Several β-unsubstituted (Z)-γ-alkylidenebutenolides have been prepared in highly stereocontrolled fashion by implementing a steric directing group stratagem in the vinylogous aldol condensation of butenolides with aldehydes. Applications to the synthesis of the antitumor heptene (S)-melodorinol and a thiophenelactone from Chamaemelum nobile L. are described.
通过在烯丙基
缩醛与醛的缩合反应中引入空间位阻基团,以高度立体控制的方式制备了几种β-未取代(Z)-γ-烯丙基
丁烯醇。本文介绍了将这种方法应用于合成抗肿瘤庚烯(S)-美洛多林和来自夏枯草的
噻吩内酯。