GRAPHICAL ABSTRACT ABSTRACT Two facile syntheticapproaches to the novel biologically interesting 1-thiocyclopropanecarboxylates starting from corresponding thiols were developed. Approach A involved five steps with the key steps being the SN2 reactions of thiols and α-bromobutyrolactone and cyclopropane formation via t-BuOK-mediated intramolecular SN2 cyclization. It had advantages such as inexpensive
图形摘要 摘要 开发了从相应的硫醇开始的新型生物学上有趣的 1-硫代环丙烷羧酸盐的两种简便合成方法。方法 A 涉及五个步骤,关键步骤是硫醇和 α-溴丁内酯的 SN2 反应以及通过 t-BuOK 介导的分子内 SN2 环化形成环丙烷。它具有试剂便宜和操作简单等优点,但也存在一些限制,例如相对较多的反应步骤以及与具有酸性和碱性官能团的硫醇不相容。方法 B 涉及两个步骤,关键步骤是使用 1,3,2-二氧杂硫杂环戊烷-2,2-二氧化物在羧酸酯基团的 α 位形成 LDA 介导的环丙烷。它显示出诸如反应步骤少和操作简单等优点,但也存在一些局限性,例如相对昂贵的试剂以及与具有酸性官能团的硫醇不相容。这两种方法在很多方面是互补的,可以根据合成方法特点的具体要求灵活选择。
A facile route to homochiral sulfoxides
作者:Kevin Burgess、Ian Henderson
DOI:10.1016/s0040-4039(01)80467-6
日期:1989.1
Biocatalytic resolutions of methyl sulfinylacetates fford sulfoxides (R)-(1) - (6) in very high optical yields; the products have been used in a systematic study of the “SPAC” reaction, an asymmetric synthesis of γ-hydroxy-α,β-unsaturated esters.
The preparation of (Z)-α-fluoroalkenoates from readily available methyl-tert-butylsulfanyl- or tert-butylsulfinylfluoroacetate 1 or 5 is described. This short synthesis, based on a direct extrusion of SO2 from β-hydroxysulfoxides, presents a moderate to high selectivity and affords (Z)-α-fluoroalkenoates in 40–81% overall yields without purifications of the intermediates. This procedure was applied