油菜素甾醇类似物(醚类侧链)的合成

The Synthesis of Ether-like Side Chain Analogue of Brassinosteroid

运用经典的 Williamson 法和相转移催化的方法合成了油菜素甾聚类似物的?类侧链中间体(?a～c)。对以“四氢吡喃醚”式保护妊娠烯醇酮(3)C-3 位羟基的方法作了改进,大大地缩短了室温反应时间,且产率略有提高。研究了酮体(4)的硼氢化钠还原和硼氢化钾-聚乙二醇400的还原反应条件。全部合成条件温和,后处理简便。

Ether-like side chain analogues <6a-c>f Brassinosteroid were synthesized by the classical Williamson method or under phase transfer catalysis. The C3-OH group of the starting material prognenolonc (3) was protected with 3,4-dihydro-2H-pyran in an improved way giving (4). The reaction conditions of ketone(4) reduction using NaBH4 and KBH4-PEG400 were investigated. All the syntheses were carried out under mild conditions leading to a convenient professing of the reactions.