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Maresins are among the most potent antiinflammatory lipid metabolites. We report stereoselective syntheses of maresin 2 and maresin 2n-3 DPA. The anti-diol was constructed through epoxide ring opening of an optically active β,γ-epoxy aldehyde, synthesized in situ by Swern oxidation of the corresponding alcohol. Finally, the target compounds were synthesized through a Sonogashira coupling of a C9–C22 iodide and methyl (Z)-oct-4-en-7-ynoate or methyl oct-7-ynoate, respectively.

One of the most important approaches to the preparation of aldehydes from benzylic alcohols is the use of DMSO-based systems, including DMSO/oxalyl chloride/Et3N (Swern oxidation),1,2 DMSO/DCC/H+ (...

3,3,7,7-tetrakis(difluoroamino) octahydro-1,5-dinitro-1,5-diazocine (HNFX) is a high-density energetic oxidizer with four difluoroamino groups (-NF2). In this study, 1,5-ditosyl-1,5-diazocane-3,7-dione, as an important intermediate for synthesis of HNFX, was successfully synthesized using Swern oxidation in a traditional batch reactor and a continuous flow microreactor, respectively. 1,5-dotosyl-1,5-diazocane-3,7-dione was characterized by HPLC, FTIR, 1H NMR, 13C NMR, Mass spectrometry, and X-ray crystal diffraction. Compared with the traditional batch reactor, the microreactor showed several advantages, including less reaction time, milder reaction temperature, higher yield and selectivity for 1,5-ditosyl-1,5-diazocane-3,7-dione. Moreover, the microreactor could ensure the safer and large-scale industrial production of 1,5-ditosyl-1,5-diazocane-3,7-dione. However, some solids produced in Swern oxidation which might block the channels (diameter of 0.3 mm) in the microreactor. To overcome the challenges, the experimental device was modified to suit for Swern oxidation, contributing to wider application of the microreactor. Besides, response surface methodology (RSM) was introduced and an appropriate mathematical model was built to optimize experimental conditions. The optimum experimental parameters were recommended as 7.8 ℃ for the reaction temperature, 7.7 mL/min for the flow rate, and 6% for the concentration of oxalyl chloride. The actual yield of 1,5-ditosyl-1,5-diazocane-3,7-dione was 89.7%, which was in great agreement with the highest predicted yield (90.1%).

Hyacinthacines C1 and C4 are natural products that were isolated from Hyacinthoides non-scripta and Scilla socialis in 1999 and 2007, respectively. Despite their different 1H NMR and 13C NMR spectroscopic data, these compounds have been assigned the same structures, including absolute configurations. This work details the total synthesis of natural (+)-hyacinthacine C1, whose structure is confirmed as being the C-6 epimer of that reported. The synthetic strategy focused on inverting the configuration at C-1 of the final hyacinthacines via operating the inversion at the corresponding carbon atom in three previously synthesized intermediates. To do this, the advanced intermediates were subjected to Swern oxidation, followed by a stereoselective reduction with L-Selectride. This approach led to the synthesis of (+)-5 -epi-hyacinthacine C1 (15), the corrected structure for (+)-hyacinthacine C1 (19), (+)-6,7-di- epi-hyacinthacine C1 (23), and (+)-7- epi-hyacinthacine C1 (29). Glycosidase inhibition assays revealed that (+)-hyacinthacine C1 (19) proved the most active, with IC50 values of 33.7, 55.5, and 78.2 μM, against the α-glucosidase of rice, human lysosome, and rat intestinal maltase, respectively.

Swern oxidation is widely used to convert alcohols into their corresponding carbonyl compounds. However, the conventional method with use of the volatile oxalyl chloride as an activator requires the reaction to be conducted below −60 °C. We discovered that 3,3-dichloro-1,2-diphenylcyclopropene (DDC) can be used as a new activator for Swern-type oxidations of alcohols, which can be conducted at −20 °C. This new protocol features mild and fast reactions with easy operation. Furthermore, the activator DDC is easy to handle, and diphenylcyclopropenone can be recovered quantitively. This new type of Swern oxidation shows a broad scope of substrates including benzylic, allylic, aliphatic, and biobased alcohols, and gives high yields of up to 93%.

Ever since Hirata’s report of yuzurimine in 1966, nearly fifty yuzurimine-type alkaloids have been isolated, which formed the largest subfamily of the Daphniphyllum alkaloids. Despite extensive synthetic studies towards this synthetically challenging and biologically intriguing family, no total synthesis of any yuzurimine-type alkaloids has been achieved to date. Here, the first enantioselective total synthesis of (+)-caldaphnidine J, a highly complex yuzurimine-type Daphniphyllum alkaloid, is described. Key transformations of this approach include a highly regioselective Pd-catalyzed hydroformylation, a samarium(II)-mediated pinacol coupling, and a one-pot Swern oxidation/ketene dithioacetal Prins reaction. Our approach paves the way for the synthesis of other yuzurimine-type alkaloids and related natural products., Despite being known for more than 50 years, yuzurimine-type alkaloids have not been accessed by total synthesis. Here, the authors report the first enantioselective total synthesis of (+)-Caldaphnidine J, a highly complex yuzurimine-type Daphniphyllum alkaloid.

Oxalyl chloride, (COCl)2, as an inexpensive commercially available chemical is one of the most versatile applicable organic reagents in chemical transformations. It is also employed extensively in various chemical industries. It is employed in various chemical transformations such as chlorination, oxidation, reduction, dehydration, decarboxylation, and formylation reactions as well as ring cleavage of epoxides. During the past decades, numerous procedures using (COCl)2 as reagent have been developed and published. However, its importance has largely been overlooked by the absence of a comprehensive review in chemical literature dealing with its application in organic transformations and its utilization in the chemical industry. This Review aims to provide an overview for the applications of oxalyl chloride in organic synthesis, including its physical properties, synthesis, as well as its unique roles as the reagent in organic reactions, covering the literature over the past 103 years (from 1916 to date).

The total synthesis of 16-membered C2–Symmetric dilactone (-)-Pyrenophorol was accomplished starting from commercially available (S)-epoxide prepared by hydrolytic kinetic resolution of (±)...

Methods for the synthesis of phenylacetaldehydes (oxidation, one-carbon chain extension) were compared by using the synthesis of 4-methoxyphenylacetaldehyde as a model example. Oxidations of 4-methoxyphenylethanol with activated DMSO (Swern oxidation) or manganese dioxide gave unsatisfactory results; whereas oxidation with 2-iodoxybenzoic acid (IBX) produced 4-methoxyphenylacetaldehyde in reasonable (75%) yield. However, Wittig-type one-carbon chain extension with methoxymethylene-triphenylphosphine followed by hydro­lysis gave an excellent (81% overall) yield of 4-methoxyphenylacetaldehyde from 4-methoxybenzaldehyde (a cheap starting material). This approach was subsequently used to synthesise a set of 10 substituted phenylacetaldehydes in good to excellent yields.

Preparation of benzaldehyde by Swern oxidation of benzyl alcohol was carried out in a continuous flow microreactor system. Dimethyl sulfoxide (Me2SO) was used as oxidizing agent and oxalyl chloride or p-toluenesulfonyl (p-TsCl) chloride was used as the activating agent. Benzyl alcohol was oxidized to benzaldehyde by the Me2SO-activating agent mixture in the continuous flow microreactor system. The optimized reaction conditions of the Swern oxidation were as follows: oxalyl chloride was used as the activating agent; the mole ratio of Me2SO, oxalyl chloride, and benzyl alcohol was 4:2:1; the ow rate of Me2SO was 1.5 mL/min; the reaction temperature was 15 ℃; length of delay loop was 1.5 m; a Caterpillar Split-Recombine Micro Mixer was used; and all of the experiments were completed at atmospheric pressure. The yield of benzaldehyde can reach 84.7% with selectivity of 98.5%. Due to the small reactor volume and short residence times, the Swern oxidation of benzyl alcohol in a continuous flow microreactor system can be operated at nearly room temperature (5–19 ℃) instead of –70 ℃ in a batch reaction, with residence time of reactants in microreactors in milliseconds instead of several hours in a batch reaction.

β-D-Idopyranosides are interesting sugars because of their unusual conformational flexibility in the pyranosyl ring, and also their β-1,2-cis-anomeric configuration. Here we report our studies of the regioselective opening of 4,6-O-benzylidene-protected β-D-idopyranosides under reducing conditions, and the subsequent 6-homologation via Swern oxidation and Wittig olefination to afford a 6,7-dideoxy-β-D-ido-hept-6-enopyranoside. This olefination product was found to adopt predominantly 1C4 conformation in solution by NMR experiments, which places the vinyl group at a more sterically hindered axial position and creates difficulty in subsequent hydroborations.

A conversion of trimethylsilylalkanes into the corresponding alcohols is established based on an iridium-catalyzed, chemoselective C(sp3)–H borylation of the methyl group on silicon. The (borylmethyl)silyl group formed by C(sp3)–H borylation is treated with H2O2/NaOH, and the resulting (hydroxymethyl)silyl group is converted into a hydroxyl group by Brook rearrangement, followed by oxidation of the resulting methoxysilyl group under Tamao conditions. An alternative route proceeding through the formylsilyl group formed from a (hydroxymethyl)silyl group by Swern oxidation is also established. The method is applicable to substituted trimethylsilylcycloalkanes and 1,1-dimethyl-1-silacyclopentane for conversion into the corresponding stereodefined cycloalkyl alcohols and 1,4-butanediol.

The Burgess reagent ([methoxycarbonylsulfamoyl]triethylammonium hydroxide) has historically found utility as a dehydrating agent. Herein we show that, in the presence of dimethyl sulfoxide, the Burgess reagent efficiently and rapidly facilitates the oxidation of a broad range of primary and secondary alcohols to their corresponding aldehydes and ketones in excellent yields and under mild conditions, and can be combined with other transformations (e.g., Wittig olefinations). A mechanism similar to those described for the Pfitzner-Moffatt and Swern oxidations is proposed.

A simple approach has been developed for the sulfenyllactonization of alkenoic acids using dimethyl sulfoxide activated with oxalyl chloride, in which methanesulfenyl chloride is proposed as the intermediate.

In a one pot procedure , a series of novel Triazole linked thiazolidenone derivatives 8 a-g and 9 a-g was prepared by condensation of (3a R ,5 S ,6 R ,6a R )- 6-((1-(4-fluorophenyl)-1 H -1,2,3-triazol-4-yl)methoxy)-2,2-dimethyltetrahydro[2,3- d ][1,3]dioxole-5- carbaldehyde 7 with mercapto acids and primary amines in presence of ZnCl 2 under both micro wave irradiation and conventional heating conditions. Compound 7 prepared from di Acetone D- Glucose with oxidation followed by reduction , click reaction, primary acetonide deprotection and with oxidative cleavage .Characterization of new compounds has been done by means of IR, NMR, MS and elemental analysis. The nematicidal and anti bacterial activity of the compounds has also been evaluated.

The synthesis and structure of the substituted trioxane compound 2,4,6,-tri­cyclo­butyl-1,3,5-trioxane is described. The three cyclo­butane rings attached to the 1,3,5-trioxane six-membered ring are all in a cis arrangement. The compound may find application as a stable trimeric form of the fragile cyclo­butane carbaldehyde., The synthesis and structure of 2,4,6,-tri­cyclo­butyl-1,3,5-trioxane, C15H24O3 1, is described. It was formed in 39% yield during the work-up of the Swern oxidation of cyclo­butyl­methanol and may serve as a stable precursor of the cyclo­butane carbaldehyde. The mol­ecule of 1 occupies a special position (3.m) located at the center of its 1,3,5-trioxane ring. The latter is in a chair conformation, with the symmetry-independent O and C atoms deviating by 0.651 (4) Å from the least-squares plane of the other atoms of the trioxane ring. All three cyclo­butane substituents, which have a butterfly conformation with an angle between the two planes of 25.7 (3)°, are in the cis conformation relative to the 1,3,5-trioxane ring. Inter­molecular C—H⋯O inter­actions between the 1,3,5-trioxane rings consolidate the crystal structure, forming stacks along the c-axis direction. The crystal studied was refined a as a racemic twin.

The cyclohexenone derivatives pleosporols A, B and stemfolone B were reported as novel antibacterial agents. In this study, we reported the first total synthesis of pleosporol A and its stereoisomers from arabinose, utilizing intramolecular nitrone-alkene cycloaddition and Hofmann elimination under Swern condition for constructing the cyclohexene ring.

An efficient multigram-scale synthesis of methyl 2,3,4,6-tetra-O-benzyl-L-glycero-α-D-manno-heptopyranoside from methyl 2,3,4-tri-O-benzyl-α-D-mannopyranoside is reported. It involves a sequence of Swern oxidation, Grignard addition and Fleming-Tamao reactions. The resulting scaffold was used as a precursor to design a small library of clickable L-heptosides. This study shows that the use of mercuric bistrifluoroacetate is required both to accelerate and to cleanly perform the Fleming-Tamao oxidation, without side-reactions.

The first total synthesis of neurotrophic diacetylenic tetraol, petrosiol A and stereoselective total synthesis of petrosiol E was accomplished. The total synthesis involves Cadiot-Chodkiewicz coupling reaction as the key step for petrosiol A. The diastereorich chiral alcohol (third chiral center) was synthesized from CBS mediated stereoselective ketone reduction reaction for petrosiol E. Of the three chiral centers, the two chiral centers are originated from (+)-diethyl l -tartrate and the third chiral center was generated by an addition reaction of lithium trimethylsilylacetylide leading to two diastereomers which were used for the synthesis of both the natural products and their diastereomer C6-epi-petrosiol A and C6-epi-petrosiol E, respectively.

The crystal solvates of 2,2′-, 2,3′- and 3,3′-bis(dipyrrinato)zinc(II) with acetone, dimethyl sulfoxide, and triethylamine were obtained by slow crystallization. Composition, stability, and spectral luminescent properties of the samples were studied. Spectroscopic studies showed that the quantum yield (φ) of crystal solvates in cyclohexane is noticeably lower (to ~1.5–4.5 times) than φ for of [Zn2 L 2] helicates. The thermal dissociation processes of crystal solvates in an argon atmosphere have been investigated. It is shown that bis(dipyrrinato)zinc(II) form stable supramolecular complexes with electron donor molecules X of the composition [Zn2 L 2Xn], where n = 1, 2, or 4. Crystal solvates are stable up to a temperature ~356.9–412.2 К. The energy stability of the solvates [Zn2 L 2Xn] reduced at replacing the 2,2′-bis(dipyrrine) on 2,3′- and 3,3′-isomer and with a decrease in electron donor number of molecular ligands X: Acet, DMSO, TEA. It is demonstrated that the high energies of the coordination interactions Zn–X in supramolecular complexes [Zn2 L 2Xn] are the main cause of the fluorescence quenching of [Zn2 L 2] luminophores in the presence of electron donor ligands X. The obtained results are of interest for the development on the basis of [Zn2 L 2] of the new fluorescent sensors of the electron donor molecules.

The addition of bromomagnesium 2-vinyloxy ethoxide to various aldehydes in the presence of 10 mol% Sc(OTf) 3 provides a broad range of functionalized protected aldol compounds. The enantioselective preparation of these aldols can be achieved via a Swern oxidation–CBS reduction sequence. Use of the dioxolane derived from 2-bromocyclohexanone provides the expected aldol product as the anti diastereoisomer (dr >99:1).

A highly enantioselective hydrogenation of heteroaromatics bearing a hydroxyl group, 3-hydroxypyridinium salts, has been successfully developed using chiral iridium catalyst, providing a direct access to trans 6-substituted piperidin-3-ols with up to 95% ee. Swern oxidation of the hydrogenation products affords chiral 6-substituted piperidin-3-ones, which are easily reduced to cis 6-substituted piperidin-3-ols using K-selectride.

In order to improve the antitumor and/or antiviral activities of existing nucleoside analogs, eight new compounds (9a,b, 14a,b, 15a,b and 16a,b) were designed and synthesized. Halogen atom were incorporated at the 2-position of the purine base to render the amino group at the 6-position less susceptible to metabolism by adenosine deaminase. A methylene group was introduced at the 2′-position following the lead of nucleoside antibiotics angustmycin A and neplanocin A. The two key intermediates 9a and 9b were prepared from guanosine after protection of the 3′ and 5′ hydroxyl groups and oxidation of the 2′ hydroxyl group to the corresponding carbonyl group using swern method. The conversion of the carbonyl group to the methylene function was carried out by applying wittig reaction conditions. The final compounds 14a,b, 15a,b, 16a,b were prepared by means of nonaqueous diazotization of 9a and 9b. The prepared compounds were subjected to in vitro antileukemic and antiviral activity upon a new L1210 cell line that is doubly resistant to both hydroxyurea and deoxyadenosine which was grown and characterized. The new compounds showed potent antileukemic activity.

An efficient asymmetric synthetic route for the synthesis of anti-glaucoma agent, (15R)-latanoprost using Corey lactone diol as chiral substrate under Swern oxidation, allylic reduction and Wittig reaction conditions has been developed. In this method, reduction of keto and alkene functional groups has been achieved in a single step using low cost catalyst NiCl2/NaBH4 in methanol. This new synthetic protocol is a good alternative for the synthesis of latanoprost with high stereo selectivity and improved yield.

The preparation of nitriles from primary amides or aldoximes was achieved by using oxalyl chloride with a catalytic amount of dimethyl sulfoxide in the presence of Et3N. The reactions were complete within 1 h after addition at room temperature. A diverse range of cyano compounds were obtained in good to excellent yields, including aromatic, heteroaromatic, cyclic, and acyclic aliphatic species.

Lignin, the planet's most abundant renewable source of aromatic compounds, is difficult to degrade efficiently to welldefined aromatics. We developed a microwave-assisted catalytic Swern oxidation system using an easily prepared catalyst, MoO2 Cl2 (DMSO)2 , and DMSO as the solvent and oxidant. It demonstrated high efficiency in transforming lignin model compounds containing the units and functional groups found in native lignins. The aromatic ring substituents strongly influenced the selectivity of β-ether phenolic dimer cleavage to generate sinapaldehyde and coniferaldehyde, monomers not usually produced by oxidative methods. Time-course studies on two key intermediates provided insight into the reaction pathway. Owing to the broad scope of this oxidation system and the insight gleaned with regard to its mechanism, this strategy could be adapted and applied in a general sense to the production of useful aromatic chemicals from phenolics and lignin.

The stereoselective synthesis of resolvin D4 (RvD4) was achieved using the Wittig reaction of the C1–C10 dienal with the known C11–C22 phosphonium salt. The (S,E)-enantiomer (S)-10, corresponding to the C1–C8 part, was synthesized in 95% ee by the asymmetric transfer hydrogenation reaction of the corresponding acetylenic ketone followed by Red-Al reduction. Sharpless epoxidation of this alcohol using Ti(O-i-Pr)4/l-(+)-DIPT as a catalyst produced anti epoxy alcohol with >99% ee as the sole product in 82% yield. A subsequent functional group manipulation, including removal of the PMB group, produced the alcohol, which upon Swern oxidation afforded anti 4-hydroxy-5-TBS-oxy enal via epoxide ring opening of the resulting aldehyde. The Horner–Wadsworth–Emmons reaction was used to add the C9–C10 enal part to this aldehyde, and the resulting dienal was subjected to the Wittig reaction with C11–C22 phosphonium salt to furnish the entire structure of RvD4. Conversion of the primary alcohol to the methyl ester and d...

Intramolecular carbolithiation of 3-lithioxy-5-hexenyllithiums was studied. Unlike the case of 5-hexenyllithium, the cyclization of 3-lithioxy-5-hexenyllithium was very sluggish. Acceleration was observed when lithium chloride was added, suggesting that intramolecular lithioxy coordination would hinder the cyclization. Introduction of a silyl or thiophenyl group at the olefin terminus caused smooth cyclization. The resulting dianions having a cyclopentane framework are subjected to C–C bond-forming reaction with electrophiles to give 3-substituted cyclopentanols. Coupled with the Swern oxidation, the overall protocol served as a platform for 3-substituted cyclopentanones.

The Moffatt-Swern oxidation (MSO) is a multistep, versatile, metal-free reaction by which alcohols are transformed into aldehydes and ketones. Batch MSO requires low temperatures (−70 °C) due to a highly exothermic reaction step that generates intermediates. This work shows that a rigorous investigation of the MSO in batch can be used as a stepping-stone to its implementation in a continuous-flow reactor (CFR). This work has two parts: the first part details the investigation of MSO in batch; the second covers the translation of the knowledge derived from batch to a CFR. The MSO batch reaction was performed under cryogenic conditions with real-time process monitoring. The reaction was monitored with Raman spectroscopy and could be tracked throughout the reaction. All concentrations were validated using offline high-performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GC-MS). Two configurations of the CFR were produced. Configuration 1 used the traditional batch methodology in...

The total synthesis of pectinolide H and 4'- epi -pectinolide H was accomplished with 27% yield in nine steps from inexpensive and commercially available compound, (+)-diethyl tartrate ((+)DET)) by employing swern oxidation, Wittig olefination, Grignard and lactonization reactions.