The first stereoselective total synthesis of the Z-isomer of cytospolide E

A convergent and highly stereoselective total synthesis of the Z-isomer of cytospolide E has been achieved via Evan’s aldol reaction, Sharpless kinetic resolution and RCM cyclisation.     

Progress towards the total synthesis of 2,3-dihydroxytrinervitanes

Intramolecular Diels-Alder approach to construct the fused AB ring of trinervitane has been demonstrated efficiently. The key intermediate for the Diels-Alder cyclization has been achieved following highly stereoselective Julia-Kocienski olefination, Sharpless epoxidation and Evan’s asymmetric alkylation as the key reactions.     

The first stereoselective and the total synthesis of Leiocarpin C and total synthesis of (+)-Goniodiol

The synthesis of the styryl lactone Leiocarpin C has been achieved in a highly stereoselective manner using Jacobsen’s kinetic resolution, Sharpless asymmetric epoxidation and Sharpless asymmetric dihydroxylation as key steps. This is the first total synthesis of Leiocarpin C, and thus establishes for the first time the absolute stereochemistry of this natural product.     

Stereoselective total synthesis of (+)-boronolide, (+)-anamarine, 8-epi-spicegerolide

A stereoselective total synthesis of the naturally occurring cytotoxic lactones (+)-boronolide, (+)-anamarine, and 8-epi-spicigerolide is described. d-Xylose has been used as a chiral source to construct the four contiguous oxygenated stereogenic centers of target molecules. The diastereoselective allylation was performed using Brown’s protocol and the lactone moiety was prepared by ring closing metathesis.     

A stereoselective total synthesis of (−)-andrachcinidine via an olefin cross-metathesis protocol

A stereoselective total synthesis of 1-(2S,6R)-6-[(2S)-2-hydroxypentyl]-hexahydro-2-pyridinylacetone, (−)-andrachcinidine is reported. The strategy utilizes olefin cross-metathesis and intramolecular S_N2 cyclization as the key steps.     

Synthesis of the peptide moiety of the jamaicamides

The jamaicamides, isolated from cyanobacterium Lyngbya majuscula in Jamaica, are unique mixed polyketide-peptides that are reported to be blockers of the sodium channels. The peptide moiety contains a pyrrolinone ring and a β-methoxy enone functionality. Herein, we report the stereoselective synthesis of the N-(Boc)₂-protected peptide moiety of the jamaicamides by utilizing Meldrum’s acid starting from l-alanine and N-Boc-β-alanine.     

Formal total synthesis of borrelidin: synthesis of C1-C11 fragment via desymmetrization strategy

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.     

First stereoselective total synthesis of Phomolide G and H via RCM protocol

A first total synthetic route has been reported for the synthesis of Phomolide G and H. The syntheses of fragments were initiated from commercially available and inexpensive starting material (R)-epichlorohydrin. The synthesis involves a key Sharpless epoxidation, stereoselective epoxide opening, lactonization and ring closing metathesis (RCM).     

Stereoselective synthesis (+)-cephalosporolide D

A simple and efficient stereoselective synthesis of macrolactone, (+)-cephalosporolide D has been accomplished in 13 steps from inexpensive and commercially available starting materials in an overall yield of 17%, respectively. This convergent synthesis utilizes Maruoka asymmetric allylation reaction, Grubb’s cross metathesis for the formation of a fully functionalized acid, and Yamaguchi lactonization as key steps.     

Highly stereoselective bioreduction and one-way isomerization of 2-alkyl-4,4,4-trichloro-2-butenals

This article describes a highly stereoselective bioreduction of 2-alkyl-4,4,4-trichloro-2-butenals (1a: Me, 1b: Et) mediated by baker’s yeast (Saccharomyces cerevisiae). The E-isomers were regiospecifically converted into the saturated alcohols 2 with high enantioselectivity, whereas the Z-isomers generated in situ by a competitive one-way isomerization were reduced only into the corresponding allyl alcohols 3 during the reactions.     

First stereoselective total synthesis of decarestrictine O via RCM protocol

A convergent first stereoselective total synthesis of decarestrictine O via RCM protocol starting from 1,3-propanediol and propylene oxide is reported.     

Ugi-type four-component reaction for a novel synthesis of 5-oxo-perhydrofuro[3,2-b]pyran carboxylate derivatives

The four-component coupling (4CC) of sugar hydroxyaldehyde, Meldrum’s acid, isocyanide, and a secondary alcohol in dichloromethane has been accomplished at room temperature in a highly stereoselective manner to produce a novel class of carbohydrate derivatives, 5-oxo-perhydrofuro[3,2-b]pyrans in good yields with trans-selectivity. The stereochemistry of the products was assigned by various NMR experiments.     

Stereoselective total synthesis of penaresidin A starting from d-galactal

A stereoselective total synthesis of penaresidin A has been accomplished involving Sharpless asymmetric epoxidation, regioselective ring-opening of epoxide, azetidine formation via S_N2 reaction, Jung’s protocol, and Julia–Kocienski olefination. This approach has successfully demonstrated the synthetic utility of d-galactal in the construction of azetidine core of the natural product.     

Total synthesis of 8-methoxygoniodiol related compounds via chiron approach

The stereoselective synthesis of 8-methoxygoniodiol related compounds was accomplished by using readily available δ-gluconolactone as a chiral source. The stereoselective addition of an aryl Grignard reagent on an aldehyde, stereoselective reduction of a keto group and regioselective opening of a chiral epoxide by ethyl propiolate are the key steps involved in this synthesis.     

Stereocontrolled synthesis of novel 6′(α)-hydroxy carbovir analogues

This paper describes the racemic and stereoselective synthetic route for a novel 6′(α)-hydroxy-carbovir from a simple acyclic precursor, Solketal. The relative stereochemistry of the target nucleosides was successfully controlled by a sequential stereoselective glycolate Claisen rearrangement followed by a ring-closing metathesis (RCM). Adenine and cytosine were coupled using a Pd(0) catalyzed allylic alkylation strategy in a high regio- and stereoselective manner.     

New reactions of alkynes with ketones in superbasic media

The present work reviews new reactions of alkynes with ketones in the superbasic media MOH—DMSO (M = Na, K, Cs) and KOBu^t—DMSO: the stereoselective nucleophilic addition of deprotonated ketones to the triple bond to form the E-isomers of β,γ-enones; vinylation of tertiary acetylenic alcohols that formed in situ from acetylene and ketones; the direct synthesis of vinyl ethers of tertiary acetylenic alcohols from acetylene and ketones; the stereoselective synthesis of dispirocyclic ketals containing the Z-ethylene fragment from arylalkynes and two molecules of a cyclic ketone; the stereoselective cascade synthesis of hexahydroazulenones from two arylalkyne molecules and 2-alkylcyclohexanones; the stereoselective cascade assembly of 7-methylidene-6,8-dioxabicyclo[3.2.1]octanes from two acetylene molecules and two ketone molecules; the stereoselective cascade synthesis of 7-methylidene-6,8-dioxabicyclo[3.2.1]octanes from acetylenes and 1,5-diketones; and the three-component cascade reaction of acetylene, ketones, and oximes to afford 4-methylidene-3-oxa-1-azabicyclo-[3.1.0]hexanes.     

2-Isopropylbenzimidazole and 2-methylbenzimidazole as bulky proton sources: Stereoselective protonation and application to the synthesis of γ- and δ-lactones

2-Isopropylbenzimidazole and 2-methylbenzimidazole have been found to be effective bulky proton sources for stereoselective protonation of chiral enolate anions. 2-Isopropylbenzimidazole worked in the stereoselective protonation of the Birch reduction of chiral α,β-unsaturated imides. On the other hand, 2-methylbenzimidazole was found to be the best protonation reagent in the isomerization reaction of α,β-unsaturated imide into β,γ-unsaturated imide. The Birch reduction using 2-isopropylbenzimidazole realized a concise and stereoselective synthesis of δ-lactone 14, a sex pheromone of Macrocentrus grandii, while the isomerization reaction using 2-methylbenzimidazole was employed in the highly stereoselective synthesis of the γ-lactone intermediate in the synthesis of depsipeptide antibiotics. These bulky proton sources would be powerful tools to achieve a concise synthesis of natural products.     

Stereoselective approach to pentenocins using RCM: synthesis of 6-epi-pentenocin B

The stereoselective synthesis of 6-epi-pentenocin B 3 is described using a stereoselective Grignard reaction and ring-closing metathesis (RCM) as the key steps.     

The total synthesis of (±)-cycloeudesmol

The highly stereoselective total synthesis of (±)-cycloeudesmol was achieved by the stereoselective cyclopropane ring formation of an epoxy alcohol ($\text{7}$) as a key reaction.     

A stereoselective approach to the synthesis of pseudodistomin D

A stereoselective total synthesis of the core unit of pseudodistomin D, starting from l-serine, is described. The key step is a stereoselective intramolecular Michael reaction in which the piperidine ring is formed with the obtention of 1.