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A convergent and stereoselective approach for the synthesis of C1–C23 and C24–C32 segments of polyether antibiotic, ionomycin has been achieved. The key steps involved in this approach are the elaboration of two advanced fragments from a common precursor using enzymatic desymmetrization to create two methyl chiral centers, desymmetrization of the bicyclic olefin to introduce two methyl and two hydroxyl chiral centers, the use of Evans auxiliary to introduce another methyl group and the creation of four chiral centers in bis -tetrahydrofuran ring by Sharpless asymmetric epoxidation and the regioselective opening of epoxide with methyl sulphone. The coupling of C11–C16 with C17–C23 was achieved through a Julia-Kocienski olefination and directed Aldol reaction. Oxidation of C9 alcohol facilitates the coupling of C10–C23 with C1–C9. [ABSTRACT FROM AUTHOR]

Abstract: A stereoselective synthesis of tetrahydropyran–tetrahydrofuran (THP–THF) core 2 of (+)-muconin (1) has been achieved using Prins cyclization as a key step to construct tetrahydropyran moiety. Other important transformations such as Wittig olefination, Sharpless epoxidation, regio-, and stereoselective exo-cyclization of the epoxy alcohol, titanocene induced regioselective deoxygenation of 2,3-epoxy alcohol, Grignard reaction, and Barton–McCombie reaction are successfully employed to accomplish the synthesis of THP–THF core 2. [Copyright &y& Elsevier]

Abstract: The highly stereoselective total synthesis of polyacetate α,β-unsaturated δ-lactone natural product (+)-synargentolide A has been accomplished from inexpensive d-1,5-gluconolactone. Key reactions involved in the synthesis are hydroboration, Wittig olefination, Brown’s asymmetric allylation, and a ring closing metathesis reaction. [Copyright &y& Elsevier]

Abstract: The O-propargyl derivative of a sugar aldehyde derived from d-glucose undergoes smooth intramolecular domino Knoevenagel–hetero-Diels–Alder reactions with 1,3-diketones in the presence of CuI/Et3N system in refluxing methanol to afford a novel class of carbohydrate analogues, furopyranopyrans in good yields. 1-Aryl-pyrazol-5-ones also undergo smooth coupling with O-propargyl tethered sugar aldehyde under similar conditions to furnish pyrazole-annulated furopyranopyrans. The stereochemistry of the products was assigned by various NMR experiments. [Copyright &y& Elsevier]

Abstract: An efficient and highly stereoselective asymmetric synthesis of C1–C9 and C9–C17 fragments of (+)-13-deoxytedanolide have been achieved. Utilization of desymmetrization technique to prepare the triol with five stereogenic centers, regioselective Sharpless asymmetric dihydroxylation, Evans'' aldol reaction, chiral methylation, and Wittig olefination are highlights of the synthesis. [Copyright &y& Elsevier]

Abstract: A simple and efficient total synthesis of five-membered pyrrolidine, (+)-pseudohygroline is described. The key steps involved in this synthesis are highly stereoselective Prins cyclisation followed by reductive ring opening and hydroboration. [Copyright &y& Elsevier]

Abstract: A protective group free, concise, and stereoselective total synthesis of (+)-artemisinin, starting from readily available (R)-(+)-citronellal, is described. Asymmetric 1, 4-addition, Aldol condensation, Ene reaction, regioselective hydroboration are the key steps involved in the total synthesis of the target molecule. [Copyright &y& Elsevier]

Abstract: A stereoselective formal total synthesis of borrelidin is described. The synthetic strategy for synthesis of C1–C11 fragment features desymmetrization of Diels–Alder adduct, Sharpless asymmetric epoxidation, regioselective opening of chiral epoxide, and alkylation using Evans chiral auxiliary. [Copyright &y& Elsevier]

Abstract: A highly stereoselective asymmetric total synthesis of marine polypropionate (−)-baconipyrone C has been achieved. Utilization of desymmetrization technique to create five stereogenic centres, Sharpless epoxidation, Gilman''s reaction and resolution of methyl group using enzyme PS-C is the highlight of the synthesis. [Copyright &y& Elsevier]

Starting from 2,3-O-isopropylidene-D-glyceraldehyde (3) as chiral material, (R)-(-)-rhododendrol 2, the aglycone of the naturally occurring rhododendrin 1 was synthesized. [ABSTRACT FROM AUTHOR]

Lipoxygenases are a group of non-heme iron containing dioxygenases catalyzing the addition of molecular oxygen to poly unsaturated fatty acids in a stereospecific as well as regiospecific way and involved in the biosynthesis of inflammatory mediators, in cell differentiation and atherogenesis. Synthetic use of lipoxygenase over the last decade for total synthesis of several natural products, e.g. 6(R)-lopoxin A, 5(S)-HPETE, (R) and (S) coriolide is discussed in this review. In the second part of the review we have discussed on the LOX biocatalysis of unnatural substrates mimicking natural substrates, lipoxygenase biocatalysis in non-conventional media, the use of immobilized LOX and biocatalysis with engineered lipoxygenase. The factors governing the regiospecificity as well as stereospecificity of LOX biocatalysis will also be discussed here. From the synthetic chemist’s point of view, the asymmetric oxygenation reaction of unnatural substrates has a tremendous potential. The products of these reactions are important chiral building blocks for the total synthesis of numerous biological active natural products. [Copyright &y& Elsevier]

Abstract: An efficient stereoselective formal synthesis of marine derived monocyclic ether (−)-brevisamide is reported. The key steps involved in this synthesis are syn-Aldol reaction, Sharpless asymmetric epoxidation, and stereoselective construction of tetrahydropyran ring by 6-endo-cyclization of suitably substituted hydroxy styrylepoxide. [Copyright &y& Elsevier]

Abstract: A simple and highly efficient stereoselective total synthesis of (+)-garvensintriol, isolated from the stem bark of Goniothalamus arvensis, is described using Sharpless kinetic resolution, MacMillan α-hydroxylation, and Horner–Wadsworth–Emmons olefination as the key steps. [Copyright &y& Elsevier]

Abstract: The first total synthesis of (3R),(5R)-5-hydroxy-de-O-methyllasiodiplodin and its epimer is reported from malic acid. The adopted approach is highly convergent and stereoselective. The strategy utilizes syn selective reduction and ring-closing metathesis as key steps. [Copyright &y& Elsevier]

Abstract: A facile stereoselective total synthesis of secondary metabolite (+)-polyrhacitide A is described. Stereoselective aldol reaction, Horner–Wardsworth–Emmons reaction, Evans acetal intramolecular oxa-Michael reaction and diastereoselective syn reduction reaction are the key steps involved in the target synthesis. [Copyright &y& Elsevier]

Abstract: A total synthesis of erogorgiaene is described in 16 steps. The synthesis relies upon a highly diastereoselective intramolecular Friedel–Crafts reaction of an oxetane derived via an asymmetric syn aldol coupling. [Copyright &y& Elsevier]

A concise and flexible stereoselective route to synthesize both enantiomers of the highly functionalized α,β-unsaturated-δ-lactones, altholactone and isoaltholactone, from readily available cinnamyl alcohol is described. This approach derived its asymmetry from Sharpless catalytic asymmetric epoxidation and Sharpless asymmetric dihydroxylation reactions. The resulting diols were produced in high enantiomeric excess and were cyclized in a stereoselective manner in the presence of a catalytic amount of camphor sulphonic acid. [Copyright &y& Elsevier]

Abstract: A highly stereoselective synthesis of (−)-dihydrotetrabenazine has been accomplished using (R)-tert-butanesulfinamide as a chiral source. The synthesis involves the allylation of chiral N-sulfinyl imine followed by ring closure of the resulting secondary amide with a tethered halide and the Evans-Aldol reaction as key steps. [Copyright &y& Elsevier]

Abstract: The first efficient total syntheses of 3((1R,2R)- and 3((1S,2R)-2-(12-methyltridecyl)cyclopropyl)propanoic acid have been achieved following a chelation controlled modified Simmon–Smith cyclopropanation, Wittig reaction, Horner–Wadsworth–Emmons olefination, and p-toluenesulfonyl hydrazide catalyzed hydrogenation as key reactions in good overall yield. [Copyright &y& Elsevier]

Abstract: A general synthetic approach has been developed for the first asymmetric total synthesis of tuberolactone 1, jasmine lactone 2 and δ-decalactone 3. The key step is the selective hydrogenation of triple and endocyclic double bonds in the key intermediate 4. [Copyright &y& Elsevier]

The diastereoselective total syntheses of dodoneine (1) and epidodoneine (2) have been accomplished with an overall yield 11.2%. The key steps involved in this approach are Jacobsen hydrolytic kinetic resolution, Prins cyclisation and ring closing metathesis (RCM). The Prins cyclisation has successfully been utilized for the first time to construct ant i-1,3-diols, which are key precursors for dodoneine and its diastereomer, epidodoneine. This approach is highly diastereoselective to generate the required stereocenters of the natural product. To create your abstract, type over the instructions in the template box belowFonts or abstract dimensions should not be changed or altered. Leave this area blank for abstract info.Stereoselective total syntheses of dodoneine and its diastereomer, epidodoneine via Prins cyclisation. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract: A new l-prolinamide trifunctional catalyst has been developed for the enantioselective aldol reaction of various aromatic and aliphatic aldehydes with acetone. This method provides high yields of β-hydroxyketones (up to 90%) with good enantioselectivity (up to 92%) at a low catalyst loading (10mol%). [Copyright &y& Elsevier]

Abstract: A convergent stereoselective total synthesis of (+)-anamarine via cross-metathesis (CM) protocol starting from 2-butyn-1,4-diol and vinyl lactone is reported. Other key features of the strategy include the use of Sharpless asymmetric epoxidation, Sharpless dihydroxylation, and Red-Al reduction. [ABSTRACT FROM AUTHOR]

Abstract: The enantioselective total synthesis of (+)-patulolide C isolated from Penicillium urticae has been achieved from commercially available 9-decen-1-ol. Jacobsen’s kinetic resolution and sequential α-aminooxylation and Horner–Wadsworth–Emmons (HWE) olefination followed by Yamaguchi lactonization are used as the key reaction steps. [Copyright &y& Elsevier]

Abstract: First stereoselective total synthesis of nonenolide stagonolide G involving a convergent strategy is described. The key reactions include Keck allylation and Grubbs ring closing metathesis reaction. [Copyright &y& Elsevier]

Abstract: Asymmetric synthesis of putaminoxin, a phytotoxic macrolide from the cultured dinoflagellate Amphidinium sp., has been accomplished. Absolute configuration of putaminoxin was concluded to be 1 from comparison of the NMR data and [α]D values of synthetic and natural putaminoxin. [Copyright &y& Elsevier]

Abstract: The first total synthesis of (3S,4R)-dihydroxy-(6S)-undecyl-α-pyranone 1 and total synthesis of (2S,3R,5S)-(−)-2,3-dihydroxytetradecan-5-olide 2 have been achieved in five steps in a highly stereoselective manner using Maruoka allylation, olefin cross-metathesis, and Sharpless asymmetric dihydroxylation as key steps. [Copyright &y& Elsevier]