A total synthesis of the C/D rings - side chain fragment of vitamin D and sterols, using Mukaiyama - Michael conjugate addition
作者:Stanisław Marczak、Jerzy Wicha
DOI:10.1016/0040-4039(93)88122-y
日期:1993.10
Vitamin D and the sterol C/D -sidechain fragments 16 and 17 were synthesized from ketene acetal 4 derived from 6-methylheptanoic acid, 2-methylcyclopent-2-en-1-one (5) and allyl methyl carbonate, using Mukaiyama-Michael conjugate addition and Tsuji alkylation as the key steps.
维生素d和甾醇C / d -侧链片段16和17是从乙烯酮合成缩醛4从6-甲基庚酸,2-甲基环戊-2-烯-1-酮(衍生5)和烯丙基甲基碳酸酯,使用Mukaiyama-迈克尔共轭加成和Tsuji烷基化是关键步骤。
Synthesis of a Vitamin D<sub>3</sub> Hydrindan Ring−Side-Chain Building Block, Involving Tandem Conjugate Addition and Alkylation Reactions
作者:Paweł Grzywacz、Stanisław Marczak、Jerzy Wicha
DOI:10.1021/jo9705834
日期:1997.8.1
Vitamin D-3 hydrindan ring-side-chain building block 4 (racemic) has been synthesized from ketene acetal 12 (derived from 6-methylheptanoic acid), 2-methylcyclopent-2-en-1-one (13), allyl methyl carbonate, and dimethyl methylphosphonate. The Mukaiyama-Michael conjugate addition of 12 and 13 yielded the adduct 11 (lk) accompanied by ca. 10% of its diastereomer. Allylation of 11 with allyl methyl carbonate in the presence of palladium catalyst afforded 10. The latter was transformed into enol lactone 26, which on treatment with 2 equiv of lithium dimethyl methylphosphonate and then 1 equiv of acetic acid provided 4.