A Convenient Synthesis of Enantiomerically Pure (2<i>R</i>,3<i>S</i>)- and (2<i>S</i>,3<i>R</i>)-3-Hydroxy-2-methylbutanoic Esters
作者:Yves Petit、Caroline Sanner、Marc Larchevêque
DOI:10.1055/s-1988-27629
日期:——
Both enantiomers of erythro methyl or ethyl 3-hydroxy-2-methylbutanoate were prepared by reaction of lithium dimethylcuprate with enantiomerically pure cis-2,3-epoxybutanoic esters derived from L- or D- threonine.
Synthesis of (+)-Xylogiblactones B and C through a Kinetic Resolution of the Allenoate γ-Addition: Stereochemical Establishment
作者:Aimin Zhang、Gyungah Pak、Suh Young Yu、Sehui Yang、Jimin Kim
DOI:10.1021/acs.joc.2c02711
日期:2023.2.17
Concise syntheses of naturally occurring γ-butenolides (+)-xylogiblactones B and C have been achieved for the first time startingfrom commercial methyl crotonate in 5–8 steps. The synthetic course involves allenoate γ-addition to racemic aldehydes through a kinetic resolution to establish the required stereochemical framework as center and axial chirality and subsequent oxacyclization via gold catalysis
从商业巴豆酸甲酯开始,通过 5-8 个步骤首次实现了天然存在的 γ-丁烯酸内酯 (+)-木糖内酯 B 和 C 的简明合成。合成过程包括通过动力学拆分将联烯酸 γ-加成到外消旋醛,以建立所需的立体化学框架作为中心和轴向手性,随后通过金催化进行氧杂环化以完成 (+)-木糖内酯骨架。两种关键的转变都以区域特异性和立体特异性的方式进行。这一结果依赖于找到一种有效的外消旋醛合成方法作为动力学拆分的前体。合成的完成为 (+)-木内酯 B 和 C 提供了立体化学澄清。
Optical rotatory dispersion studies. 135. Synthesis and chiroptical properties of (S)- and (R)-(3-2H1)-2,2-dimethylcyclobutanone. Evidence for conformational effects in substituted cyclobutanones
作者:R. N. Harris、P. Sundararaman、C. Djerassi
DOI:10.1021/ja00346a050
日期:1983.4
Synthesis and reactions of 3-hydroxy-2-nosyloxy esters produced by the stereoselective reduction of 2-nosyloxy-3-keto esters
作者:Robert V. Hoffman、Hwa Ok Kim
DOI:10.1021/jo00024a013
日期:1991.11
The reduction of 2-nosyloxy-3-keto esters is an effective method for the preparation of 3-hydroxy-2-nosyloxy esters. The reduction is stereoselective for the syn isomer. The anti isomer can be produced as the major product by the addition of p-nitrobenzenesulfonyl peroxide to ketene bis-silyl acetal derivatives of 3-hydroxy esters. The diastereomers are separable chromatographically and can be converted stereospecifically to glycidic esters and 2-azido-3-hydroxy esters. As such they appear to have excellent potential as versatile synthetic intermediates for the synthesis of 1,2,3-trifunctional substances.