Synthesis of 2-Methyl and Ethyl-Substituted 19-nor-1α,25-Dihydroxyvitamin D3 Analogues via the Cyclovitamin Strategy
作者:Yu-Rui Zhao、Bing Guang、Roger Bouillon、Annemieke Verstuyf、Pierre De Clercq、Maurits Vandewalle
DOI:10.1002/ejoc.200500289
日期:2005.10
The synthesis of several 19-nor-2-alkyl-1α,25-dihydroxyvitamin D3 analogues (5–14) is described following the cyclovitamin strategy. Starting from all-cis methyl 3,5-dihydroxy-4-alkyl-1-cyclohexanecarboxylate (29), the eight stereoisomeric A-ring-precursor 2-tert-butyldiphenylsilyloxy-3α-formyl-1-alkylbicyclo[3.1.0]hexanes (39, 44, 46, 63, 65, 67, 69, 71) were prepared in two series: a (R = methyl)
根据环维生素策略描述了几种 19-nor-2-烷基-1α,25-二羟基维生素 D3 类似物 (5-14) 的合成。从全顺式 3,5-二羟基-4-烷基-1-环己烷羧酸甲酯 (29) 开始,八种立体异构 A 环前体 2-叔丁基二苯基甲硅烷氧基-3α-甲酰基-1-烷基双环 [3.1.0] 己烷(39, 44, 46, 63, 65, 67, 69, 71) 以两个系列制备:a (R = 甲基) 和 b (R = 乙基)。特别是,通过偶联 39 和衍生自具有天然或 23-yne 侧链的 CD 环溴化物 20 和 21 的锂化化合物,合成了标题衍生物 5-14。(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)