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The prevalence of Clostridium difficile (CD) infection has grown rapidly due to resistance and the emergence of new, highly virulent strains of the organism that have become less sensitive to many antibiotics. Vancomycin and metronidazole are front-line treatments of CD infection that still show good efficacy, but their effectiveness has declined for the treatment of recurrent infection and less sensitive strains of CD. More recently, the macrolide antibiotic fidaxomicin been introduced in the treatment of CD infection. Its high cost and limited usefulness against recurrent infection has prompted the search for new, narrow spectrum agents. We identified the CD dihydroorotate dehydrogenase (DHODase) as a potential enzyme target for the design of Knoevenagel products formed from reaction of 2-thiobarbituric acid and naphthaldehyde substrates. The presence of a hydroxyl substituent at position C2 in the naphthaldehyde ring offers the possibility to form the Knoevenagel product and to cyclize to give the tetracyclic, oxadeazaflavine with benzo-homologation. In this work, the selectivity for straight-chain formation over competing cyclisation on Knoevenagel condensation between thiobarbituric acid and naphthaldehyde substrates was examined. The outcomes of uncatalyzed condensations in refluxing ethanol were investigated by various methods including high field 1H and 13C NMR. Unsubstituted naphthaldehyde and its 2-methoxyl derivative favored straight-chain product formation whereas use of 2-hydroxynaphthaldehyde favored cyclisation and concomitant Michael addition of a second molecule of the corresponding acid to the newly formed exocyclic C=C bond. The pattern of reactivity was mirrored in the benzaldehyde series where the presence of the 2-hydroxyl function led to cyclized products with concomitant formation of the Michael adducts. The Knoevenagel products and the benzo-homologated oxadeazaflavine derivatives are candidates for evaluation as potential growth inhibitors of CD.

The predominant enantiomer of nicotine found in nature is (S)-nicotine and its pharmacology has been widely established. However, pharmacologic information concerning individual enantiomers of nicotine-related compounds is limited. Recently, a modified macrocyclic glycopeptide chiral selector was found to be highly stereoselective for most tobacco alkaloids and metabolites. This study examines the semi-synthetic and native known macrocyclic glycopeptides for chiral recognition, separation, and characterization of the largest group of nicotine-related compounds ever reported (tobacco alkaloids, nicotine metabolites and derivatives, and tobacco-specific nitrosamines). The enantioseparation of nicotine is accomplished in less than 20s for example. All liquid chromatography separations are mass spectrometry compatible for the tobacco alkaloids, as well as their metabolites. Ring-closed, cyclized structures were identified and separated from their ring-open, straight chain equilibrium structures. Also, E/Z-tobacco-specific nitrosamines and their enantiomers were directly separated. E/Z isomers also are known to have different physical and chemical properties and biological activities. This study provides optimal separation conditions for the analysis of nicotine-related isomers, which in the past have been reported to be ineffectively separated which can result in inaccurate results. The methodology of this study could be applied to cancer studies, and lead to more information about the role of these isomers in other diseases and as treatment for diseases.

Students of single crystal X-ray diffraction are often give advice as to how best to collect their data when attempting absolute configuration determination. These ‘rules’ often have more grounding in gut-feeling than evidence. Thus, in an effort to provide advice and evidence that today’s crystallographers can pass onto to tomorrow’s young scientists, we present a systematic study of 1-deoxy- l -arabinitol, a straight chain sugar which crystalises well in the space group I 4 1 .

Cyclodextrins have been extensively used for inclusion of various drugs for improvement of pharmaceutical characteristics of diverse nature. Numerous derivatives of cyclodextrins are currently available and are being subjected to continuous investigations. On the other hand, urea was previously being used as host for inclusion of straight chain linear compounds. However, development of a modified technique has opened flood gates for inclusion of non-linear drugs containing cyclic moieties. Cis-retinoic acid, nicorandil, vitamin E, amiloride, glipizide, enalapril maleate, simvastatin, lafutidine and ezetimbe are some of the drugs which have already been investigated for improvement of pharmaceutical characteristics. These characteristics include improvement of stability, content uniformity, dissolution profile and rheological behavior. Recently, pesticide-fertilizer combination has also been reported to serve the dual purpose of pesticide cum fertilizer and for improvement in safe handling and formulation characteristics. All FDA approved cyclodextrins are safe chemicals for human use within permissible limits. Urea is a component of normal physiological processes of body in human beings and other mammals. Urea is far cheaper when compared to cyclodextrins. Studies reveal that despite unique characteristics of urea like high solubility, non-toxicity, stability, inexpensiveness, biodegradability and easy availability, the use of urea as a host for inclusion of drugs has been grossly overlooked by researchers. Immense potential of urea as a host for inclusion of drugs need to be explored for improvement of pharmaceutical characteristics. The relative use of both cyclodextrins and urea as hosts for inclusion of drugs has been briefly reviewed in the present article.

The EFSA Panel on Food Additives and Flavourings (FAF) was requested to evaluate 54 flavouring substances attributed to the Flavouring Group Evaluation 05 (FGE.05), using the Procedure as referred to in the Commission Regulation (EC) No 1565/2000. This Revision 3 includes 17 additional substances which have been cleared with respect to genotoxicity in FGE.200Rev1 ([FL‐no: 02.192, 02.231, 05.072, 05.144, 05.184, 05.189, 05.190, 05.191, 05.195, 09.247, 09.400, 09.866, 09.948]) and in FGE.203Rev2 ([FL‐no: 05.081, 05.186, 05.194, 05.196]). The substances were evaluated through a stepwise approach that integrates information on the structure–activity relationships, intake from current uses, toxicological threshold of concern (TTC), and available data on metabolism and toxicity. The Panel concluded that none of the 54 substances gives rise to safety concern at their levels of dietary intake, estimated on the basis of the ‘Maximised Survey‐derived Daily Intake’ (MSDI) approach. Besides the safety assessment of the flavouring substances, the specifications for the materials of commerce have also been considered and found adequate, except for 10 substances ([FL‐no: 08.072, 08.083, 08.101, 08.119, 08.120, 09.181, 09.329, 09.335, 09.379 and 09.637]) for which quantitative figures on the composition of stereoisomeric mixtures are missing and for [FL‐no: 09.578] complete specifications should be provided. Normal and maximum use levels were not available for [FL‐no: 08.072, 08.083, 08.101, 08.119, 08.120, 09.287, 09.326 and 09.578]. Except for flavouring substances [FL‐no: 05.072, 05.081, 05.186, 05.194, 05.196, 09.934 and 09.942], more reliable intake data should be requested for all the 46 flavouring substances, for which use levels were submitted, as their modified Theoretical Added Maximum Daily Intake (mTAMDI) exposure estimates are above the threshold of concern for structural classes I and II. This would include more reliable intake data and then, if required, additional toxicological data.

Density of binary mixtures of ethyl acetoacetate (EAA) with straight chain aliphatic ketones butan-2-one, pentan-2-one, hexan-2-one, heptan-2-one, octan-2-one and nonan-2-one were measured at varying compositions of the ethyl acetoacetate at 298.15 K. The derived properties such as excess molar volumes, V m E , of the binary mixtures were calculated from the experimental density data of the mixtures. The calculated excess molar volumes were fitted into the Redlich-Kister polynomial to obtain the fitting parameters and standard deviations. The excess molar volumes of the binary mixtures investigated were negative over the entire range of composition. The negative values were attributed to dipole–dipole interactions between the unlike molecules of mixtures than those between the like molecules of the pure solvents. The observed negative values of the excess molar volumes for the studied binary mixtures were discussed in terms of intermolecular interactions which were present in the mixtures.

Fluorinated surfactants are usually composed of a perfluorinated chain and a hydrophilic group. Academic surveys have reported that straight chain fluorinated surfactants have the lowest surface tension in a relatively high concentration while the branched fluorinated surfactants show more efficient in a relatively low concentration. Introducing branch is one of effective strategies for synthesis of non-bioaccumulable fluorinated surfactants. Three novel branched fluorinated surfactants were designed and prepared through a five-step route using perfluoro-2-methyl-2-pentene as starting material. The surface activities of them were investigated and found that they exhibited excellent surface activities. FCS can reduce the surface tension of water to below 20 mN/m, and the cmc value of FAS in water is about 1.04 × 10−4 mol/L at 298 K. All the values of surface properties of FCS, FGS and FAS are lower than that of sodium perfluorooctanoate.

Alkane-1,1-bistriflates, prepared in excellent yields by reaction of aldehydes with triflic anhydride, are converted to their respective 1,1-difluoroalkanes in good to excellent yield through reaction with fluorinating agent, triethylaminetrishydrofluoride. Straight chain 1,1-bistriflates are more reactive than those substituted at the 2-position, but the latter are also converted successfully, without evidence of any rearrangement products.

After completely hydrogenation of Fischer–Tropsch synthesis (FTS) products on Pt/C catalyst, the branched C8, C10, C11, and C12 alkanes were identified using authentic samples to be methyl branched alkanes in both Co and Fe catalyzed reactions. No detectable ethyl branched and dimethyl branched alkanes were observed. The total amount of branched hydrocarbons in Co catalyzed FTS is about 5 % while the amount of branched hydrocarbons in Fe catalyzed FTS is about 25 %. The branched hydrocarbon distribution of Co catalyzed FTS does not obey the Anderson–Schulz–Flory (ASF) kinetics and the branched hydrocarbon distribution of Fe catalyzed FTS shows larger α value than that of straight chain alkanes. These results were explained by the formation of 2-alkylidene through readsorbed 1-alkenes, which can grow to form methyl branched hydrocarbons. Since the rate of propagation of 2-alkylidene is much slower than that of ethylidene and 1-alkylidenes, a “kink” will result in C2 in the FT product distribution plot.

Hydrazides reacted with acylpyruvic acid esters possessing a terminal straight chain alkyl substituent at the C=O bond distal from the ester group, giving 5-hydroxy-2-pyrazolines. Acylpyruvates with bulky terminal substituents underwent condensation at the C=O bond adjacent to the ester group, giving products with hydrazone or 5-hydroxy-2-pyrazoline structure and capable of displaying ring-chain equilibrium between these tautomers in solution.

The conjugate addition on a natural bioactive pseudoguaianolide sesquiterpene lactone parthenin with various Grignard reagents leads to 13-C alkylated products chemo and diastereoselectively in fair overall yields. Compared with other Grignard reagents vinyl and smaller straight chain alkyl Grignard reagents gave better yields.

Following a request from the European Commission, the EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety and efficacy of 24 compounds belonging to chemical group 4 (non‐conjugated and accumulated unsaturated straight‐chain and branched‐chain, aliphatic primary alcohols, aldehydes, acids, acetals and esters). This opinion concerns 23 compounds from this group. They are currently authorised as flavours in food. The FEEDAP Panel established the following conclusions: hex‐3(cis)‐en‐1‐ol [02.056], (Z)‐non‐6‐en‐1‐ol [02.093], oct‐3‐en‐1‐ol [02.094], non‐6(cis)‐enal [05.059], hex‐3(cis)‐enal [05.075], (Z)‐hept‐4‐enal [05.085], hex‐3(cis)‐enyl acetate [09.197], hex‐3(cis)‐enyl formate [09.240], hex‐3‐enyl butyrate [09.270], hex‐3‐enyl hexanoate [09.271] and hex‐3(cis)‐enyl isobutyrate [09.563] are safe at the proposed maximum use level of 5 mg/kg complete feed for all target species; citronellol [02.011], (‐)‐3,7‐dimethyl‐6‐octen‐1‐ol [02.229], citronellal [05.021], 2,6‐dimethylhept‐5‐enal [05.074], citronellic acid [08.036], citronellyl acetate [09.012], citronellyl butyrate [09.049], citronellyl formate [09.078] and citronellyl propionate [09.129] are safe at the maximum use level of 5 mg/kg for all species, except cats for which the proposed normal use level of 1 mg/kg is considered safe; undec‐10‐enal [05.035], 1‐ethoxy‐1‐(3‐hexenyloxy)ethane [06.081] and hex‐3‐enyl isovalerate [09.505] are safe at the normal use levels of 1 mg/kg for all species. No safety concern would arise for the consumer from the use of these compounds up to the highest safe level in feeds. Hazards for skin and eye contact, and respiratory exposure are recognised for the majority of the compounds under application. Most are classified as irritating to the respiratory system. The use of the majority of the compounds in animal feed at the maximum safe level is considered safe for the environment. As all the compounds under assessment are used in food as flavourings, and their function in feed is essentially the same as in food, no further demonstration of efficacy is necessary.

Experimental measurements of turbulent and laminar burning velocities have been made for premixed hydrocarbon–air flames of straight chain molecules of increasing carbon number (from n-pentane to n-octane). Measurements were performed at 0.5 MPa, 360 K and rms turbulent velocities of 2 and 6 m/s, for a range of equivalence ratios. The laminar burning velocities were used to interpret the turbulent data, but were also found to be broadly in line with those of previous workers. At lean conditions the turbulent burning velocity was measured to be similar between the four alkanes studied. However, at rich conditions there were notable differences between the turbulent burn rates of the fuels. The equivalence ratio of the mixtures at which the maximum burning velocities occurred in the turbulent flames was richer than that under laminar conditions. The equivalence ratio of the peak turbulent burning velocity was found to be a function of the carbon number of the fuel and the turbulent intensity and became gradually fuel rich with increases in each of these values.

A novel series of 2-acetamido and 2 or 3-propanamido derivatives of 4- or 5-substituted-thiazoles was designed and synthesized. Structure elucidation of the new synthesized compounds was attained by the use of 1 H & 13 C NMR, and Mass spectrometry. Compounds were subjected to NCI in vitro assessment for their antitumor activity, at a single dose of 10 μM of test compounds. Compounds bearing straight chain substituent or 4-phenyl function proved to be more active than their branched or 4-methyl congeners. Compounds 37 , 41 and 42 exhibited broad spectrum antitumor activity. Compounds 23 and 27 proved lethal while compounds 18 , 21 , 32 and 37 showed remarkable GI values of 75.5, 69.3, 96.2 and 92.7% to the Leukemia CCRF-CEM cell line, respectively.

The reaction of p-cymene with tert.amyl alcohol, which yields indans, has been extended to other alcohols and homologues of cymene. It has been found that straight chain secondary alcohols yield substituted cymenes, but secondary alcohols containing a tertiary carbon atom, and tertiary alcohols, yield polyalkylindans. Under the conditions of the reaction cumene does not yield indans.

Experiments were carried out to investigate the effect of pretreatment by organic solvents with different hydrophobicities, functional groups and molecular constitutions as activation agents on initial esterification activity and secondary structure of immobilized Pseudomonas cepacia lipase. The results showed that esterification activity of immobilized P. cepacia lipase treated with organic solvents containing –C O– and –C N– functional groups was highest, followed by the one treated with –C–C– functional groups but the lowest with –OH and aromatics functional groups. An organic solvent with a branched structure was more favorable compared with a straight chain in terms of enhancing enzyme activity. Conformational studies via Fourier transform-infrared spectroscopy indicated that the catalytic activity variance was attributed to the secondary structure changes for immobilized P. cepacia lipase treated with organic solvents. Moreover, the effects of moisture, pH and temperature on the esterification activity of immobilized P. cepacia lipase were also addressed.

Treatment of [Fc-1-R 1 -1′-R 2 ] (R 1 = H, R 2 = CH(O); R 1 = H, R 2 = CMe(O); R 1 = R 2 = CMe(O)) with LiC CCH 2 OLi (prepared in situ from HC CCH 2 OH and n -BuLi) affords the ferrocenyl-substituted but-2-yne-1,4-diol compounds of general formula [Fc-1-R 1 -1′-{CR(OH)C CCH 2 OH}] (R 1 = R = H ( 1a ); R 1 = H, R = Me ( 1b ); R 1 = CMe(O), R = Me ( 1c )) in low to high yields, respectively (where Fc = Fe(η 5 -C 5 H 4 ) 2 ). In the case of the reactions of [Fc-1-R 1 -1′-R 2 ] (R 1 = H, R 2 = CH(O); R 1 = R 2 = CMe(O)), the by-products [Fc-1-R 1 -1′-{CR(OH)(CH 2 ) 3 CH 3 }] (R 1 = R = H ( 2a ); R 1 = CMe(O), R = Me ( 2c )) along with minor quantities of [Fc-1,1′-{CMe(OH)(CH 2 ) 3 CH 3 } 2 ] ( 3 ) are also isolated; a hydrazide derivative of dehydrated 2c , [1-(CMe CHCH 2 CH 2 CH 3 )–1′-(CMe NNH-2,4-(NO 2 ) 2 C 6 H 3 )] ( 2c ′), has been crystallographically characterised. Interaction of 1 with Co 2 (CO) 8 smoothly generates the alkyne-bridged complexes [Fc-1-R 1 -1′-{Co 2 (CO) 6 -μ-η 2 -CR(OH)C CCH 2 OH}] (R 1 = R = H ( 4a ); R 1 = H, R = Me( 4b ); R 1 = CMe(O), R = Me ( 4c )) in good yield. Reaction of 4a with PhSH, in the presence of catalytic quantities of HBF 4 · OEt 2 , gives the mono- [Fc-1-H-1′-{Co 2 (CO) 6 -μ-η 2 –CH(SPh)C CCH 2 OH}] ( 5 ) and bis-substituted [Fc-1-H-1′-{Co 2 (CO) 6 -μ-η 2 -CH(SPh)C CCH 2 SPh}] ( 6 ) straight chain species, while with HS(CH 2 ) n SH ( n = 2,3) the eight- and nine-membered dithiomacrocylic complexes [Fc-1-H-1′-{ cyclo -Co 2 (CO) 6 -μ-η 2 -CH(S(CH 2 ) n –)C CCH 2 S–}] [ n = 2 ( 7a ), n = 3 ( 7b )] are afforded. By contrast, during attempted macrocyclic formation using 4b and HSCH 2 CH 2 OCH 2 CH 2 SH dehydration occurs to give [Fc-1-H-1′-{Co 2 (CO) 6 -μ-η 2 -C( CH 2 )C CCH 2 OH}] ( 8 ). Single crystal X-ray diffraction studies have been reported on 2c ′, 4b , 4c , 7b and 8 .

A gas-chromatographic technique is described whereby fatty acids up to C34 may be separated as their methyl esters. Application to commercial fatty acid mixtures revealed the presence of acids with odd numbers of carbon atoms and small amounts of acids hitherto unidentified in such mixtures.

Seven coal and carbonaceous mudstone samples were collected from outcropping Jurassic coal beds, on the margin of the Dingxi Basin, Northwestern China. The n -alkane distributions in all of the samples are characterised by high concentrations of the C 19 –C 29 homologues, and very much lower amounts outside of this range. C 23 or C 24 are usually the most abundant n -alkanes. Straight chain n -alkanes from C 23 to C 29 show moderate odd-to-even C number predominances (CPI range: 1.26–2.70). Long-chain acyclic n -alkan-2-ones, n -alkan-3-ones and n -alkan-4-ones ranging from C 15 to C 33 with moderate odd-to-even C number predominances, were detected together with one isoprenoid methyl ketone (6,10,14-trimethylpentadecan-2-one) in all of the samples. The C number distributions of the three series of alkanones show a similar distribution to that of the n -alkanes, but the correspondence is not sufficient to substantiate a product–precursor relationship. It can be concluded that the n -alkan-2-ones are a mixture of the products of microbially-mediated β-oxidation of corresponding n -alkanes in the sediments and from the microbial oxidation of higher plant-derived n -alkanes prior to incorporation in the sediments. The n -alkan-3-ones and n -alkan-4-ones were formed from microbially mediated oxidation of the corresponding n -alkanes in the γ and δ positions, respectively. Generation of the ketones from higher plant n -fatty alcohols and n -alkanoic acids could be a possible way to form some of the ketones observed, but it can only play a minor role in the samples analysed.

Synthetic dispersants can greatly increase the solubility of asphaltenes in crude oils at low concentrations. They have one or more head groups that complex with the polynuclear aromatic structures in asphaltenes and long paraffinic tails that promote solubility in the rest of the oil. As a result, synthetic dispersants can be much more effective than the natural dispersants in the oil, the resins. At high concentrations, synthetic dispersants can even make all the asphaltenes soluble in n-heptane and thereby convert asphaltenes to resins. Asphaltene dispersants were optimized according to their ability to reduce the toluene equivalence of 05a crude oil. By synthesizing families of prospective dispersants, one sulfonic acid group was determined to be the most effective head attached to a two ring aromatic structure. As previously reported, a straight chain paraffinic tail is not effective above 16 carbons. We discovered that this was because of decreased solubility in the oil caused by crystalliz...

The interfacial tension (IFT) of 1 M solutions of N,N-dialkyl amide in n-dodecane against water and nitric acid has been measured at 303K. Ten amides, namely, dibutyl hexanamide (DBHA), diisobutyl hexanamide (DiBHA), dibutyl octanamide (DBOA), dihexyl hexanamide (DHHA), dibutyl dodecanamide (DBDA), di n-octyl butanamide (DOBA), diisooctyl butanamide (DiOBA), di n-octyl isobutanamide (DOiBA), di n-hexyl octanamide (DHOA), and di n-octyl hexanamide (DOHA) were synthesized and used. The effect of concentration of DOHA on IFT against 3 M nitric acid was also studied. It was observed that the introduction of branching in an amide on either the acyl or the nitrogen side increases the IFT over its straight chain analogue, as in the case of DiOBA, DOiBA, and DiBHA. Increasing the carbon chain length on the acyl side, keeping the total carbon number constant, was found to increase the IFT considerably. Increasing the concentration of the amide resulted in a decrease in the IFT values, due to the lowering of the concentration of hydrophobic diluent. An increase in the uranium loading of the organic phase in the case of 1 M DOHA, was found to increase the IFT.

Biolubricants from Castor oil were produced enzymatically by transesterification with higher alcohols using a lipase mixture of immobilized Mucor miehei (RMIM) and immobilized Candida antarctica lipase B (Novozym 435) under low water conditions. The conversions were in the range of 80–95% under the optimized conditions.

The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to evaluate the genotoxic potential of 74 flavouring substances from subgroup 1.1.1 of FGE.19 in the Flavouring Group Evaluation 200 (FGE.200). The Flavour Industry has provided additional genotoxicity studies for one representative substance in FGE.200, namely hex-2(trans)-enal [FL-no 05.073], and for other two substances in the same subgroup, namely 2-dodecenal [05.037] and 2-nonenal [05.171]. The Panel has evaluated these data and concluded that the concern still remains with respect to genotoxicity for the substances of this subgroup and their three representative substances. The Panel confirms, the need for an in vivo Comet assay performed in duodenum and liver for hex-2(trans)-enal [FL-no: 05.073]. For the two other representative substances of subgroup 1.1.1 (nona-2(trans),6(cis)-dienal [FL-no: 05.058] and oct-2-enal [FL-no: 05.060]), a combined in vivo Comet assay and micronucleus assay would be required. For the latter, evidence of bone marrow exposure should be provided.

The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to evaluate the genotoxic potential of flavouring substances from subgroup 3.2 of FGE.19 in the Flavouring Group Evaluation 215 (FGE.215). The Flavour Industry has provided in vitro genotoxicity studies for the representative substances in FGE.215, namely 4-phenylbut-3-en-2-one [FL-no: 07.024] and 1-(4-methoxyphenyl)pent-1-en-3-one [FL-no: 07.030]. Based on these genotoxicity data, the Panel concluded that the genotoxicity concern could not be ruled out and in vivo genotoxicity data are requested.

The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to evaluate the genotoxic potential of flavouring substances from subgroup 1.1.4 of FGE.19 in the Flavouring Group Evaluation 203, Revision 1 (FGE.203Rev1). The Flavour Industry has provided additional genotoxicity studies for one representative substance in FGE.203, namely 2,4-decadienal [FL-no: 05.140]. Based on the available data, on newly submitted studies and on the scientific evidence from the literature, the Panel concluded that the genotoxic potential cannot be ruled out for the flavouring substances in this FGE.

The rate of condensation of a series of alcohols with N,N-diethylaminotrimethylsilane have been measured. It was observed that the relative rate varied inversely with the chain length of the straight chain primary alcohols investigated. Branched alcohols reacted at slower rates than the straight chain alcohols through n-octyl alcohol.

Stereoselective reduction of a triple C-C bond and chemoselective transformation of an azide function into amino group have been employed in the synthesis of straight-chain primary E and Z allylic amines from alk-2-yn-1-ols.

This paper describes the synthesis of ( Z )-1-chlorovinyl sulfoxides 1 by the Horner-Wittig reaction. The required [(α-chloro)sulfinylmethyl]diphenylphosphine oxides 2 (R 1 =Me, c -Hex, Ph, p -Tol, p -(CF 3 )Ph), were prepared in high yields by selective monochlorination and subsequent monooxidation of (thiomethyl)diphenylphosphine oxides 3 . The stable lithiated anions of 2 gave an efficient reaction with all structural types of aldehydes. Aromatic and α,β-unsaturated aldehydes gave 1 with excellent Z -selectivity (> 98%), irrespective of the nature of the substituent R 1 at sulfur. With straight chain aliphatic aldehydes, an aromatic substituent at sulfur was required to obtain high Z -selectivity. A mechanistic explanation for these observations is presented. An X-ray analysis of 1 , R 1 =Me, R 2 =4-MeOC 6 H 4 confirmed the Z -disposition of the chloro and aryl substituents.

The radical cyclisation reaction of the 5-[2-bromo-ethyl]-5H-dibenzo[ a , d ]cycloheptene 4 with Bu 3 SnH and AIBN led to the cyclised hydrocarbon 5 as major product, whereas the bromo-derivative 8 with Bu 3 SnH and AIBN gave only the straight chain product 9 . An explanation based on the conformational rigidity of dibenzo[ a , d ]cycloheptene system calculated by AM1 method is proposed.

About 170 compounds were identified in the headspace or liquid exudate from garden waste. Typical for microbiological growth were branched and straight chain alcohols, carboxylic acids and esters C 2 –C 8 . Several of the substances have been identified in early studies of compost For some waste samples the organosulfur compound concentration (C 1 and C 3 mono-, di- and trisulfides) was ca. 10 mg/m 3 which suggests that these substances may contribute to mucous membrane irritation or nausea reported by waste collection personnel.

The sex pheromone of Scrobipalpula absoluta (Meyrick) (Lepidoptera: Gelechiidae) was identified as a 92:8 mixture of (3E,8Z,11Z)-3,8,11-tetradecatrienyl acetate (1) and (3E,8Z)-3,8-tetradecadienyl acetate (2) through mass spectrometric investigation of the dimethyl disulphide derivatives of excised sex pheromone glands. It is the first time that this method was used for triple unsaturated straight chain molecules. Compound (2) was identified as a new pheromone component. A synthetic mixture of the two identified compounds proved to be attractive in wind tunnel experiments.

A series of analogues of 2-phenylmorpholines with alkyl substituents at the C-3 position were synthesized for anti-tetrabenazine (anti-TBZ) testing in mice. The target compounds were prepared by reaction of (2-bromoalkyl) phenyl ketones 21a-h with the appropriate aminoalcohol 20a-b to form morpholinols 22a-h. Hydride reduction of the morpholinols gave aminodiols 23a-h which were cyclized to morpholines 6, 8, 10–12, 14–16, 18 and 19 by acid catalaysis. Compounds 7, 9, 13 and 17 were prepared by reductive formylation. The smaller straight chain substituents of 6, 8, 12 and 15, and the beta branching of the iso-butyl group of 16 were well tolerated; anti-tetrabenazine ED50′s were comparable to compounds 2–5. The α-branched, N-methylated, and side chain aryl derivatives were less active.

The light induced isomerization of 4-N,N-dimethylaminobenzonitrile (DMABN) has been measured versus pressure to 10 kbar in ethanol, n-butanol, n-pentanol, iso-butanol and glycerol. or the three straight chain alcohols a linear plot of log(ITICT/ILE) versus α log η (η=viscosity) was obtained with α = −0.5 ± 0.02. Iso-butanol gave a non-linear plot of the above variables and at any viscosity the value of ITICT/ILE was greater than for n-butanol, although those two alcohols have nearly identical values for their electronic and volumetric properties. The results for glycerol extend the viscosity range significantly and exhibit distinctly non-linear behavior for the above type of plot.

A series of branched esters (methyl 2,2-dimethylpropanoate to ethyl 2-ethylhexanoate) were purified by preparative gas chromatography and their odor thresholds were determined using sensory panel methods. The odor thresholds reached a minimum with the butanoate and pentanoate esters. In general, the branched esters have much lower odor thresholds than their straight chain counterparts. Replacing methyl and ethyl branch substituents with mercapto- or hydroxy-groups resulted in higher odor thresholds.

A convenient method has been developed to selectivly form the monotriphenylmethyl derivatives of symmetric 1,n-diols, both straight chain and cyclic, in moderate to high yields.

Infrared and low-frequency Raman data evidence the presence of the crystalline phase in the gels prepared from ultra-high molecular weight polyethylene. The straight chain segment length distribution covers the range from 1 to 10 nm with a sharp maximum at 3 nm. The latter peak is attributed to chain-folded crystals while the wings of the distribution are referred to the contribution of adjoined straightened portions of different molecules. The crystalline sites of both kinds serve as junctions in newly formed polymeric network.

The cocondensation of atomic carbon with water at 77 K generates a mixture of straight chain aldoses with up to five carbons. A proposed mechanism involves initial reaction of C with H 2 O to give hydroxymethylene which rearranges to formaldehyde. Subsequent nucleophilic addition of hydroxymethylene to formaldehyde with hydrogen transfer generates glycolaldehyde which reacts with additional hydroxymethylenes to build up the higher carbohydrates. Confirmation of this mechanism is provided by deuterium labeling studies

Two new halogenating reagents, viz. allyltriphenoxyphosphonium bromide (ATPB) and allyltriphenoxyphosphoniurn chloride (ATPC) have been prepared and characterised. These have been evaluated for their potential application in bromination/ chlorination of a variety of compounds including aliphatic straight chain alcohols, branched chain alcohols and also 3'and s··hydroxy groups of deoxyribonucleosides.

The preference for chair- and boatlike transition-state geometries in the ester enolate Claisen rearrangement of straight chain, carbocyclic, and heterocyclic propanoates was investigated. A novel stereoelectronic effect in pyranoid and furanoid glycal systems leads to a significant relative stabilization of the boatlike vs the chairlike TS : . The preferred transition state in six- and five-membered carbocyclic systems is highly dependent on steric factors, as the energy difference between chair- and boatlike TS : tends to be small. With straight-chain substrates, a significant contribution of the boatlike TS : to the rearrangement product mixture is only expected in bis-donor substituted allylic esters

Tri(2-ethylhexyl) amine (TEHA) was found to be a considerably weaker extractant for mineral acids than straight chain aliphatic amines. It is still, however, markedly stronger than solvating extractants such as alcohols and esters. Its medium strength provides for a relatively wide range of efficient and reversible extraction. TEHA and similarly branched chain tertiary amines are therefore suitable for recovery of strong mineral acids from effluents containing them in low concentrations. Effects of diluents and modifiers and of amine concentration were found to provide a strong tool for adjusting the range of efficient and reversible extraction to characteristics of treated solutions.

The composition of the volatile fraction from Cochlospermum tinctorium rhizome was investigated by GC and GC-MS; among 11 constituents detected, eight were identified as straight chain ketonic compounds. In addition, five triacylbenzenes were isolated from a petrol extract of the rhizome, separated by HPLC and identified by their spectral data.

Mishra, Shashank Jeanneau, Erwann Daniele, Stephane Ledoux, Gilles Swamy, Pralkash N.; Solvated yttrium iodide precursors [Y(L)(8)]l(3) [L = dimethylformamide (DMF) or dimethylsulf oxide (DMSO)], prepared in situ by stirring Y-3(PrOH)(4) in DMF/DMSO, react with 3 equiv of Pbl(2) in the presence of NH(4)l to give novel hybrid derivatives based on either a one-dimensional (1D) straight chain, [Y(DMF)(8)][Pb-3(mu-l)(9)](1 infinity) center dot DMF (1), or discrete pentanuclear iodoplumbates, [Y(DMSO)(8)](2)[(DMSO)(2)Pb-5(mu(3)-l)(2)(mu-l)(8)l(6)] (2a). The complex 2a and a closely related [Y(DMSO)(8)][Y(DMSO)(7)(DMF)][(DMSO)(2)Pb-5(mu(3)-l)(2)(mu-l)(8)l(6)] (2b) were obtained in good yield by solution phase transformation of 1 in DMSO under slight different conditions. Derivatives 1 and 2 also undergo unique solid-state transformation in a confined environment of paratone to give 1D polymers based on zigzag iodoplumbate chains; crystals of 1 transform into [Y(DMF)(6)(H2O)(2)][Pb-3(mu(3)-l)(mu-l)(7)l](1 infinity) (3) via an exchange reaction, whereas those of 2a and 2b are converted into [Y(DMSO)(7)][Pb-3(mu(3)-l)(mu-l)(7)l](1 infinity) (4) via a decomposition pathway. The trifurcate H-bonding between water ligands on yttrium cation and iodide of the iodoplumbate anion plays a pivotal role in transforming the straight 1D polymeric Pb-l chain of 1 into a zigzag chain in 3. The thermogravimetry-differential thermal analysis studies indicate that complexes with DMF ligands are thermally more stable than those with DMSO ones, the mixed DMF-H2O ligand complex 3 being the most stable one because of the presence of strong H-bonding. Diffuse-reflectance UV-visible spectral analyses of 1-4 show an optical band gap in the 1.86-2.54 eV range, indicating these derivatives as potential semiconductors. In contrast to non-emissive 3 and 4, derivatives 1, 2a, and 2b show remarkable luminescent emission with peak maxima at 703 nm, assigned as an iodine 5p-lead 6s to lead 6p charge transfer (XM-M-CT).

A novel diester, pentacosane dioic acid dihexadecyl ester 1 has been isolated for the first time from n-hexane soxhlet extract of Acacia nilotica. Saponification of the diester reveals the presence of an alcohol, hexadecanol and pentacosane dioic acid. The structures of both the compounds are confirmed by GCMS analysis. Saponification of pet-ether extract of Acacia nilotica has been carried out. Unsaponifiable matter is further purified by column chromatography followed by repeated mixed solvent crystallization to afford heptacosan-l,2,3-triol 2.

1,5-Dideoxy-1,5-iminoalditols of various configurations as well as isofagomine were N-alkylated with non-polar straight chain spacer-arms by a set of simple standard procedures. The spacer-arms’ terminal functional groups, primary amines, were employed to introduce fluorescent tags such as dansyl and dapoxyl moieties. Resulting derivatives in the d - xylo , d - gluco , d - galacto as well as GlcNAc series showed distinctly improved glycosidase inhibitory activities compared to parent compounds and are designed to be useful analytical tools.

[reaction: see text] A combinatorial library of dipeptide N-acylethylenediamine-based ligands was synthesized by parallel solid-phase methods. These ligands were screened in crude form as catalysts for the asymmetric addition of vinylzinc reagents to aldehydes to give chiral allylic alcohols. Three sites of diversity on the ligands were optimized using a positional scanning approach. The optimized structure from the library, ligand 54, was found to catalyze the formation of 10 different (E)-allylic alcohols with enantioselectivities ranging from 90% to 95% ee. This ligand was effective for both aromatic and alpha-branched aldehydes, and vinylzinc reagents derived from both bulky and straight chain terminal alkynes.

The title reagent engaged in the modified Julia olefination with aldehydes under mild reaction conditions (DBU, CH(2)Cl(2), rt or -78 degrees C) to yield alpha,beta-unsaturated esters; aryl aldehydes and aliphatic aldehydes possessing significant chain branching elements gave trans alkene products with high stereoselectivity (E : Z up to98 : 2), while straight chain aliphatic aldehydes gave cis products preferentially (Z : E up to 92 : 8).