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Ultraviolet (UV) irradiation is a serious problem for skin health thus the interest in the research to develop sunscreen agent has been increasing. Chalcone is a promising compound to be developed as its chromophore absorbs in the UV region. Therefore, in the present work, we synthesized eight chalcone derivatives through Claisen–Schmidt condensation at room temperature. The evaluation of the optical properties of each chalcone derivatives in the UV region was conducted through spectroscopic and computational studies. The synthesized chalcones were obtained in good yields and they were active in the UV region. The results revealed that more methoxy substituents to chalcone leads toward red shift. All chalcone derivatives have high molar absorptivity value (21,000–56,000) demonstrating that they have the potential to be used as the sunscreen agent. The cytotoxicity assay showed that chalcone derivatives were demonstrating low toxicity toward normal human fibroblast cell, which is remarkable. Therefore, we concluded that the synthesized chalcones in this work were potential to be developed as novel sunscreen agents in real application.

The asymmetric synthesis of (3R,5S)-5-(aminomethyl)-3-(4-methoxyphenyl)dihydrofuran-2(3H)-one, as the most potent selective inactivator of monoamine B, was successfully achieved by applying a newly developed synthetic method toward the key γ-aminomethyl-γ-lactone via intramolecular aziridine ring opening in 63% overall yield from a commercial starting material.

This descriptive, cross-sectional study illustrates the high prevalence of intellectual impairment among students at the Kanisius Prontakan primary school near Mt. Merapi, one of the most active volcanic mountains in Indonesia. To determine the possible cause of these abnormal cognitive impairments, we considered and investigated the threats to society and the environment of the frequent volcanic eruptions, as well as the effects of malnutrition due to extreme poverty, in that area. The results showed that intellectual impairment and stunting were remarkably common among the students, with 10.7% of the students showing sigma of intellectual impairment and 96.4% showing signs of stunting. No noticeable chemical problems due to the volcanic activity were found in the drinking water, and no causes of such disorders other than poor nutrition due to poverty were found. Nevertheless, our results provide information on the high prevalence of health problems being experienced by children living in one of the most isolated and underdeveloped volcano mountain areas in Indonesia and draws attention to the severe effects of malnutrition on the development of those children.

The preparation of (S)-3-methylamino-3-[(R)-pyrrolidin-3-yl]propanenitrile (1), a key fragment of fluoroquinolone antibiotic PF-00951966 and others was achieved by N-methylative aziridine ring opening, addition of methyl group at the ring nitrogen, and ring-opening via a cyanide nucleophile in a single operation starting from bicyclic (R)-2-[(R)-pyrrolidine-3-yl]aziridine. The starting compound was elaborated from stereoselective conjugate addition of nitromethane to (R)-aziridine-2-yl acrylate followed by selective reduction without breaking the aziridine ring.

Implementation of Principles of Green Chemistry in teaching chemistry can become an essential approach to enhance students’ awareness of the environmental problem. In contrast with the goal of sustainability, chemistry practicum normally deals with chemicals and waste management which contribute to environmental problem. A shift toward more sustainable and economical experiments is essential to maintain the existence of the practicum in the senior high curriculum. Small Scale Chemistry (SSC) practicum is one of the approaches to promote sustainability in chemistry practicum by using smaller scale and safer apparatus. It is expected to produce less waste. It is also safer and more economical chemistry experiment. This research aims to study the integration of principles of green chemistry in chemistry practicum by using SSC experiment. This study investigates two main topics in senior high school chemistry subject: electrochemistry and acid-base indicator. This study has shown the practice of integration of the principles of green chemistry approach into senior high school chemistry practicum through SSC. The experiments demonstrated in this study enable us to integrate Principles of Green Chemistry in terms of preventing waste, using less hazardous chemical, and conducting safer experiments which can be implemented in senior high school chemistry practicum.

Chemistry practicum does not have to be complicated and requires expensive apparatus and chemicals, and is considered not environmentally friendly. The concept of small scale chemistry practicum is one of appropriate technology that is packaged elegantly to introduce and embed the principles of green chemistry in every chemistry experiments, and also to enhance the concepts of chemistry through verification and scientific discovery. This study aims to create the newest product, the small scale chemistry practicum module to identify the ability of the students of chemistry education study program, Sanata Dharma University, Yogyakarta in formulating predictions on phenomenon based on the insights they have, making direct observations through small scale chemistry practicum, and explaining the results of observations and emphasis on concepts in detail and depth. This research is the development research with the model of Analysis, Design, Develop, Implement, and Evaluate (ADDIE). Data were analyzed by descriptive analysis and Rasch Model. The results of the study show that the product developed has a perfect and feasible level of readability to be tested. From the content aspect, it presented in perfect criteria, as well as the construction aspect and aspect of language, also shows good value. The students already have quite an excellent ability to predict (average score= 76), observe (average score= 88.5), and explain (average score 87.5). Also, it was noted that students enthusiastically applied POE, and the results of POE students show good person reliability value (0.88) in small scale chemistry experiments. The product developed has been valid, effective, and practical for use in experiments according to experts and teachers, and good student responses (Cronbach's alpha value= 0.92) to the product.

In welcoming chemistry learning that emphasizes the quality of students, the teacher’s role is very important. As a prospective chemistry teacher, students must be prepared critically, both in terms of mastery of teaching materials and the development of learning models that are implemented. One of the alternatives offered is guided inquiry-based learning, which aims to develop students’ abilities so that exploration can continue. This study aims to develop valid dan practical product of chemical equilibrium practicum module based on guided inquiry to be used by chemistry education students in the experiment, so that students are able to think critically and reflectively. This research is a design thinking through the framework of Empathize, Define, Ideate, Prototype, and Test (EDIPT), with chemistry education students. Supporting instruments of this research include consultation sheets, observation sheets, and student response questionnaires. Data analysis was conducted in quantitative descriptive. The results of the study show that the practicum module developed can help developing the flow of students’ thinking carefully, analyse practical needs, design varied practicum topics, and reflect on experience during designing and implementing experiments. The average of students responds well to the development of the practicum module.

Reported is a tandem palladium-catalyzed Heck/regioselective C(sp

Diversely substituted oxindoles were obtained from atom economical direct C–C bond formation reactions of various substituted anilides and pyridinylamides with metal salts and oxides. The catalysts include CuO, Cu2O, FeCl3, Fe2O3, TiO2, ZnO, and Ag2O and their nanoparticles. The reaction proceeds under solvent-free and aerobic conditions in excellent yields. The reaction mechanism was proved to be a single electron transfer pathway with oxygen as the re-oxidant of the metal catalysts.

A chiral aziridine was utilized for the synthesis of the anti-bacterial natural amino acid L-(+)-furanomycin, and its analogues including 5'-epi-furanomycin and norfuranomycin. Key steps of this synthesis are the stereoselective Pd-catalyzed etherification for diallyl ethers and ring closing metathesis.

A series of α-sulfonamido-N-adamantanecarboxamide derivatives as 11β-HSD1 inhibitors was identified. Among them, compound 7j was the most active with an IC50 value of 8 nM in humans 11β-HSD1. Compound 7j exhibited reasonable stability, permeability and safety profiles (CYP and hERG). Compound 7j showed good ex vivo 11 β-HSD1 inhibition with ~80% inhibition after 20 MPK oral dosing.

Chiral aziridine-2-carboxylates have two important functional groups, the carboxylate group and aziridine ring, that are useful for synthetic purposes. As both (2R)- and (2S)-aziridine-2-carboxylates were commercialized in optically pure forms, we have studied to extend their synthetic utilities for the construction of various nitrogen-containing molecules. The C2 ester group can be transformed into aldehydes, alcohols, amides, ketones, β-ketoesters, and amines bearing diverse substituents with defined stereochemistry in high yields. In particular, ring-opening reactions of aziridines are carried out in regio- and stereoselective manners toward α- or β-amino cyclic and acyclic compounds in optically pure forms. The highlight of this chemistry based on the regio- and stereoselective functional-group transformations of aziridine-2-carboxylates is exemplified by efficient and highly stereoselective syntheses of many biologically important amines, including natural products.

Many amines are liquid and their handling is inconvenient compared with the corresponding solids. We transformed a liquid (S)-(−)-1-phenylethylamine 1 to the corresponding neutral solid form 2 by reacting with carbon dioxide. We performed reductive amination of 2 with various aldehydes 3 under solvent-free conditions to provide secondary amines 5 in high yields.

Asymmetric syntheses of biologically and pharmaceutically important (−)-hygroline, (−)-pseudohygroline, and (−)-hygrine were achieved by a newly developed ‘N-methylative aziridine ring opening reactions’ of (2S)-methoxycarbonylethylaziridine as a key step.

E-mail: wonkoo@sogang.ac.krReceived March 18, 2013, Accepted March 26, 2013Key Words : Tyroscherin, Aziridine, MCF-7, Human breast cancer, Phenylmagnesium bromideThe synthesis and biological evaluation of natural pro-ducts and their analogs have been an important subject formany medicinal chemists in order to determine the pharma-cophores of their activity and to search for a new chemicalentity with more potent biological activity and less toxicity.

Azines, pyrazoles, and pyridazinones were isolated as the sole products in high yields (>97%) by grinding solid hydrazine (H3N + NHCO2 � ) with di-carbonyl compounds or by their reaction in the absence of sol- vent. Neither catalysts nor additives were needed to promote the reactions. The solid-state and sol- vent-free reactions proceeded under ambient conditions and did not produce any wastes other than water and carbon dioxide. They are operationally easy, environmentally safe, and readily scalable, allow- ing for highly selective synthesis of compounds containing the hydrazine motif.

An efficient synthesis of (−)-8- epi -swainsonine, starting from a commercially available 1-( R )-α-methylbenzylaziridine-2-methanol, was developed. The synthetic route utilizes stereocontrolled Sharpless asymmetric dihydroxylation governed by AD-mix-β followed by an aziridine ring opening-cyclization sequence to generate the five membered N-heterocyclic ring system present in the bicyclic target. A subsequent stereoselective allylation and piperidine ring forming cyclization then produced a precursor that was converted into (−)-8- epi -swainsonine.

Copper-mediated Michael addition of ethyl bromodi­fluoroacetate to Michael acceptors is accompanied by the formation of a substantial amount of byproducts. Elucidation of their structure hinted the cause of their formation, from which we discovered a highly improved and robust protocol by treatment with protic additives such as H2O and AcOH. This modification led to significant increase of yield with concomitant decreased use of reagent.

Preparation of functionalized 3,4-dihydroisoquinolines 17a–j from (S)-N-methoxy-N-methyl-1-[(R)-1-phenylethyl]aziridine-2-carboxamide 4 is an effective route for the synthesis of 3-(hydroxymethyl)-1,2,3,4-tetrahydroisoquinolin-4-ols. Stereoselective reduction of the cyclic imines 17a–j resulted in (1S,3S,4R)-4-(tert-butyldimethylsilyl-oxy)-3-[(tert-butyldimethylsilyloxy)methyl]-6,7-dimethoxy-1,2-disubstituted-1,2,3,4-tetrahydroisoquinolines and the desilylation of the TBS groups afforded (1S,3S,4R)-3-(hydroxymethyl)-6,7-dimethoxy-1,2-disubstituted-1,2,3,4-tetrahydroisoquinolin-4-ols 19a–i in good yields. Also, an asymmetric synthesis of novel tetracyclic 3-(hydroxymethyl)-1,2,3,4-tetrahydroisoquinolin-4-ols 23 and 25 was successfully achieved via Pd-catalyzed N-arylation and C–C coupling reaction.

Heterocyclic analogs of ceramide as 3-alkanoyl or benzoyl-4-(1-hydroxy-2-enyl)-oxazolidin-2-ones were designed by binding of primary alcohol and amide in sphinogosine backbone as a carbamate. They were synthesized by addition of acyl halide to the common ring 4-(1-t-butyldimethylsilyloxyhexadec-2-enyl)-oxazolidin-2-one which was elaborated from chiral aziridine-2-carboxylate including stereoselective reduction and ring opening reactions as key steps. Other analogs with different carbon frame at C4 position which is corresponding to the sphingoid backbone were prepared from 3-cyclopentanecarbonyl-4-(1-t-butyldimethylsilyloxybut-2-enyl)-oxazolidin-2-one and straight and cyclic alkenes by cross metathesis. All compounds were tested as antileukemic drugs against human leukemia HL-60 cells. Many of them including propionyl, cyclopentanoyl and p-nitrobenzoyl-4-(1-hydroxyhexadec-2-enyl)-oxazolidin-2-ones showed better antileukemic activities than natural C2-ceramide with good correlation between cell death and DNA fragmentation. There is a drastic change of the activities by the carbon chain lengths at C4 position. Cytotoxicity was induced by caspase activation without significant accumulation of endogenous ceramide concentration or any perturbation of ceramide metabolism.

Sphingosine-1-phosphate (S1P) plays an important role in angiogenesis by stimulating DNA synthesis, chemotactic motility, and early blood vessel formation. Accordingly, the S1P signaling pathway is an attractive target for novel anti-angiogenic therapeutics. Here, we describe a small synthetic derivative of S1P that acts as an anti-angiogenic agent. We found that the S1P derivative NHOBTD [N-((2S,3R)-3-hydroxy-1-morpholino-4-(3-octylphenyl)butan-2-yl)tetradecanamide] suppressed S1P-induced invasion and tube formation by human umbilical vein endothelial cells. NHOBTD also suppressed S1P signaling, as seen by destabilization of hypoxia inducible factor-1 alpha (HIF-1α) and secretion of VEGF, a transcriptional target of HIF-1α. Moreover, NHOBTD profoundly blocked endogenous neovascularization of the chick embryo chorioallantoic membrane, without rupturing any existing vessels. Together, these results demonstrate that NHOBTD is a new anti-angiogenic molecule that is capable of perturbing S1P signaling, and provides the basis for developing new anti-angiogenic drugs.

An efficient synthesis of 1,2,5- and 1,2,3,5-substituted pyrroles has been achieved from the sequential reactions including a ring-opening of 1-(aziridin-2-yl)propargylic alcohols by various nucleophiles under mild condition followed by an intramolecular cyclization using Ag(I) catalyst.

One of stored food mites, Suidasia medanensis Oudemans, 1924 is first reported form Korea after the stored food surveys in 2008 and 2009. The morphological characteristic is given.

An efficient synthesis of enantiomerically pure aromatic-fused N-containing heterocycles was successfully achieved via Pd-catalyzed intramolecular C–N bond formation between the nitrogen originated from the aziridine and the halogen containing aromatic carbon. This reaction has a broad substrate scope to provide various enantiomerically pure (3,4-dihydro-2H-benzo[b][1,4]oxazin-3-yl)methanols, 2-hydroxymethyl-1,2,3,4-tetrahydroquinolines and (1,2,3,4-tetrahydroquinoxalin-2-yl)methanols from common chiral aziridines in good yields.

Aminoacyl-tRNA synthetases (aaRSs) play vital roles in protein biosynthesis of living organisms and are interesting antibacterial drug targets. In order to find out new inhibitor candidate molecules as antibacterial agent, the binding modes of the candidate molecules were investigated at the active sites of aaRSs by molecular docking study. The docking simulations were performed with 48 compounds from four different scaffolds into the eight different aaRSs. The results show that scaffolds 3 and 4 compounds have consistently better binding capabilities, specifically for HisRS (E. coli) and IIeRS (S. aureus). The binding modes of the best compounds with the proteins were well compatible with those of two ligands in crystal structures. Therefore, we expect that the final compounds we present may have reasonable aaRS inhibitory activity.

Substituted imidazolidin-2-ones deduced as potential inhibitors of IleRS by docking simulations were synthesized from an aziridine-2-carboxaldehyde. Reductive amination of an aziridine-2-carboxaldehyde with dipeptides for the sub- stituents at N1 and followed by aziridine-ring expansion with triphosgene afforded 4-chloromethylimidazolidin-2-ones whose chloride were further manipulated towards phenylurea, pyrimidin-2-yl-urea or benzenesulfonamide at C4.

To enrich the utility of enantiomerically pure (2R)- and (2S)-aziridine-2-carboxylates, it is necessary to develop a proper method for the preparation of 2-alkylaziridine which has vari-ous functional group in the side chain. The substitution of 2- toluenesulfonyloxymethyaziridne with alkyl nucleophiles has been studied to result limited success.

Noble metal nanocatalysts such as Pd, Pt, and Au were strongly immobilized on the inside walls of monolithic honeycomb-structured cordierite, in which bi-functional molecules were used as linkers for anchoring noble metal nanoparticles (NPs) on the cordierite surface. The supported nanocatalysts were characterized by ICP-MS, TEM, and X-ray powder diffraction. The efficiencies of the immobilized nanocatalysts for the removal of harmful nitrogen oxides (NO x ) have been investigated by measuring the deNO x capability as a function of temperature. The catalytic activities depend mainly on the compositions of the nanocatalysts. The Pd/Pt bi-metal catalyst anchored on the cordierite surface shows higher NO x conversion and better activity than the commercial emission catalyst at low temperature region, which could be due to the large portion of active surface areas of the catalysts with nanometer scale.

Candida antarctica lipase B catalyzed the stereoselective ammoniolysis of N-alkyl aziridine-2-carboxylates in tBuOH saturated with ammonia and yielded the (2S)-aziridine-2-carboxamide and unreacted (2R)-aziridine-2-carboxylate. Varying the N-1 substituent on the aziridine ring changed the rate and stereoselectivity of the reaction. Substrates with a benzyl substituent or a (1′R)-1-phenylethyl substituent reacted approximately ten times faster than substrates with a (1′S)-1-phenylethyl substituent. Substrates with a benzyl substituent showed little stereoselectivity (E=5–7) while substrates with either a (1′R)- or (1′S)-1-phenylethyl substituent showed high stereoselectivity (D>50). Molecular modeling by using the current paradigm for enantioselectivity—binding of the slow enantiomer by an exchange-of-substituents orientation—could not account for the experimental results. However, modeling an umbrella-like-inversion orientation for the slow enantiomer could account for the experimental results. Steric hindrance between the methyl in the (1′S)-1-phenylethyl substituent and Thr138 and Ile189 in the acyl-binding site likely accounts for the slow reaction. Enantioselectivity likely stems from an unfavorable interaction of the methine hydrogen with Thr40 for the slow enantiomer and from subtle differences in the orientations of the other three substituents. This success in rationalizing the enantioselectivity supports the notion that an umbrella-like-inversion orientation can contribute to enantioselectivity in lipases.

The nucleophilic substitution reactions of 1-[1′(R)-α-methylbenzyl]-(2R)- and (2S)-(sulfonyloxymethyl)aziridines were carried out with various nucleophiles including N3−, MeO−, CN−, SCN−, and diarylcuprates. The reaction pathway is influenced by the stereochemistry of the substrates, nucleophiles, and also the structure of the leaving groups. When the reaction site is less sterically hindered for the reactive nucleophiles to approach to the substrate 1-[1′(R)-α-methylbenzyl]-(2S)-(p-toluenesulfonyloxymethyl)aziridines, product is obtained as a single isomer while all the other starting materials afford a mixture of two isomers from two different reaction pathways. Application of this method enabled us to prepare both isomers of orally effective antiarrhythmic agent mexiletine.

A facile route for mono‐BOC protection of symmetrical and unsymmetrical diamines was developed by sequential additions of 1 mol of HCl and 1 mol of (BOC)2O followed by neutralization.

Diversely substituted oxindoles were obtained from atom economical direct C–C bond formation reactions of various substituted anilides and pyridinylamides with metal salts and oxides. The catalysts include CuO, Cu2O, FeCl3, Fe2O3, TiO2, ZnO, and Ag2O and their nanoparticles. The reaction proceeds under solvent-free and aerobic conditions in excellent yields. The reaction mechanism was proved to be a single electron transfer pathway with oxygen as the re-oxidant of the metal catalysts.

The immobilized cell using self-assembled synthetic oligopeptide was applied to the electrochemical detection of pathogen infection. Thin films based on cysteine-terminated synthetic oligopeptides were fabricated for the immobilization of HeLa cell on gold (Au) substrate. Layer formation and immobilization of the cell were investigated with surface plasmon resonance (SPR) and electrochemical impedance spectroscopy (EIS). Experimental results showed that the thin film of cysteine-terminated synthetic oligopeptide was successfully fabricated and it could be applied for the immobilization of HeLa cells. The adhered living cell was exposed to E. coli O157:H7, which induced the change of SPR angle and electrochemical impedance signal. The proposed cell immobilization method using self-assembly technique can be applied to construct the cell microarray for on-site pathogen monitoring.

Constrained ceramide analogs were designed and synthesized by binding terminal alcohol and amine of ceramide with additional carbonyl functional group as 3-acetyl (3), 3-propionyl (4), 3-benzoyl (5), and 3-hexadecanoyl-4-(1-hydroxyhexadec-2-enyl)-oxazolidin-2-ones (6). Compounds 4 and 5 showed potent antileukemic activities against human leukemia HL-60 cells with good correlation between cell death and DNA fragmentation.

Vibrio vulnificus was found to produce a chemical that induced the expression of Vibrio fischeri lux genes. Electron spray ionization-mass spectrometry and 1 H nuclear magnetic resonance analyses indicated that the compound was cyclo( l -Phe- l -Pro) (cFP). The compound was produced at a maximal level when cell cultures reached the onset of stationary phase. Sodium dodecyl sulfate-polyacrylamide gel analysis of the total proteins of V. vulnificus indicated that expression of OmpU was enhanced by exogenously added synthetic or purified cFP. A toxR -null mutant failed to express ompU despite the addition of cFP. The related Vibrio spp. V. cholerae , V. parahaemolyticus , and V. harveyi also produced cFP, which induced the expression of their own ompU genes. cFP also enhanced the expression in V. cholerae of the ctx genes, which are known to be regulated by ToxR. Our results suggest that cFP is a signal molecule controlling the expression of genes important for the pathogenicity of Vibrio spp.

We synthesized 2'-deoxy-2'-[18F]fluorouridine (7) as a radiotracer for positron emission tomography from a new nosylate precursor (6). This new precursor was synthesized from uridine in four steps. The overall synthetic yield was 9.4% and we have high stability of >98% purity up to 6 months at 4°C. The optimal manual [18F]fluorination conditions were 30 mg of the precursor 6 in 500 µl of acetonitrile at 145°C for 15 min with 370 MBq of [18F]fluoride. The [18F]fluorination yield was 76.5±2.7% (n = 3). After hydrolysis of protecting groups with 1 N HCl and purification by HPLC, the overall radiochemical yield and purity were 26.5±1.4% and 98.2±2.5%, respectively. The preparation time was 70.0±10.5 min (n = 3 for each result). We also developed an automated method with a radiochemical yield and purity of 24.0±2.8 and 98.0±1.5% (n = 10) using a GE TracerLab MX chemistry module. This new nosylate precursor for 2'-deoxy-2'-[18F]fluorouridine synthesis showed higher radiochemical yields and reproducibility than previous methods. Copyright © 2006 John Wiley & Sons, Ltd.

Chiral aziridine-2-carboxylates have two important functional groups, the carboxylate group and aziridine ring, that are useful for synthetic purposes. As both (2R)- and (2S)-aziridine-2-carboxylates were commercialized in optically pure forms, we have studied to extend their synthetic utilities for the construction of various nitrogen-containing molecules. The C2 ester group can be transformed into aldehydes, alcohols, amides, ketones, β-ketoesters, and amines bearing diverse substituents with defined stereochemistry in high yields. In particular, ring-opening reactions of aziridines are carried out in regio- and stereoselective manners toward α- or β-amino cyclic and acyclic compounds in optically pure forms. The highlight of this chemistry based on the regio- and stereoselective functional-group transformations of aziridine-2-carboxylates is exemplified by efficient and highly stereoselective syntheses of many biologically important amines, including natural products.

Sphingosine 1-phosphate (S1P), a product of sphingosine kinases (SphK), mediates diverse biological processes such as cell differentiation, proliferation, motility, and apoptosis. In an effort to search and identify specific inhibitors of human SphK, the inhibitory effects of synthetic sphingoid analogs on kinase activity were examined. Among the analogs tested, we found two, SG12 and SG14, that have specific inhibitory effects on hSphK2. N,N-Dimethylsphingosine (DMS), a well-known SphK inhibitor, displayed inhibitory effects for both SphK1 and SphK2, as well as protein kinase C. In contrast, SG12 and SG14 exhibited selective inhibitory effects on hSphK2. Furthermore, SG14 did not affect PKC. In isolated platelets, SG14 blocked the conversion of sphingosine into sphingosine 1-phosphate significantly. This is the first report on the identification of a hSphK2-specific inhibitor, which may provide a useful tool for studying the biological functions of hSphK2.

A highly efficient method for the synthesis of 1,4-dideoxy-1,4-imino- d - and l -arabinitol ( d -AB1, 1 and l -AB1, 3 ) and 1,4-dideoxy-1,4-imino- d - and l -xylitol ( d -DIX, 2 and l -DIX, 4 ) starting from commercially available chiral aziridines was developed. The general strategy employs a sequence involving two-carbon homologation, dihydroxylation, and regioselective aziridine ring opening/intramolecular five-membered iminosugar ring formation. The facile use of recrystallization to generate pure diastereomers makes the routes more amenable to large-scale synthesis.

Diphenyl carbonate, the key intermediate of the non-phosgene polycarbonate manufacturing process, can be produced by the transesterification of dimethyl carbonate with phenol in the presence of dibutyltin oxide. The use of an alkyl or aryl sulfonic acid in conjunction with dibutyltin oxide significantly enhances the activity of dibutyltin oxide. 19 F and 119 Sn NMR studies suggest the formation of tin complex containing strongly electrophilic sulfonate ligand from the reaction of dibutyltin oxide with alkyl or aryl sulfonic acid. Various factors affecting the transesterification of dimethyl carbonate with phenol were investigated.

A new and efficient preparation of pharmacologically and biologically important 2,5-disubstituted 6-azaindoles was achieved from cyclizations of aziridin-2-yl dipropargylic alcohols as adducts of two propargyl groups to ethyl 1-benzylaziridine-2-carboxylate. The sequential cyclizations include pyrrole formation and a novel base-catalyzed intramolecular acetylenic Schmidt reaction.