Diastereoselective Approaches to trans-Hydrindane Derivatives − Total Synthesis of 8-(Phenylsulfonyl)de-A,B-cholestane Precursors to 25-Hydroxyvitamin D3
作者:Igor Prowotorow、Wiaczesław Stepanenko、Jerzy Wicha
DOI:10.1002/1099-0690(200208)2002:16<2727::aid-ejoc2727>3.0.co;2-1
日期:2002.8
The total diastereoselective synthesis of the C,D rings/side chain building block for the synthesis of 1α,25-dihydroxyvitamin D3 is described. Two tandem Mukaiyama−Michael additions involving silylated ketene acetals derived from tert-butyl 6-methylhept-5-enethioate or tert-butyl 6-methylhept-6-enethioate, 2-methylcyclopent-2-en-1-one, and 1-(phenylthio)but-3-en-2-one afforded the corresponding intermediates
描述了用于合成 1α,25-二羟基维生素 D3 的 C、D 环/侧链结构单元的总非对映选择性合成。两个串联的 Mukaiyama-Michael 加成涉及衍生自 6-methylhept-5-enethioate 叔丁酯或 6-methylhept-6-enethioate 叔丁酯、2-methylcyclopent-2-en-1-one 和 1-(苯硫基)but-3-en-2-one 得到相应的中间体,其具有目标化合物的完整碳骨架。这些关键中间体的进一步转化包括环化、用 m-CPBA 氧化和还原乙烯基砜部分以提供反式氢化茚环系统。该合成包括五次操作,并在大约 30% 的收率。2-[(苯硫基)甲基]-2-乙烯基[1,3]二氧戊环和2-(苯磺酰基甲基)-2-乙烯基[1, 3]二氧戊环作为迈克尔受体也进行了检查。(© Wiley-VCH Verlag GmbH, 69451 Weinheim,