The total synthesis of scytophycin C. Part 1: stereocontrolled synthesis of the C1C32 protected seco acid
作者:Ian Paterson、Kap-Sun Yeung、Christine Watson、Richard A. Ward、Paul A. Wallace
DOI:10.1016/s0040-4020(98)83050-0
日期:1998.9
include: (i) the asymmetric crotylboration of (S)-18 to give homoallylic alcohol 15; (ii) the boron-mediated aldol construction of aldehyde 14 from (S)-17; (iii) the Ba(OH)2-promoted HWE reaction, 13 + 14 → 31; (iv) the highly stereocontrolled Mukaiyama aldol coupling between silyl enol ether 33 and aldehyde 11 to give adduct 10; (v) the chemoselective reduction at C17 of ketone 10 to produce 1,3-syn-diol
作为C甲立体控制合成1 C 32闭联酸衍生物9为scytophycin C(1)中的溶液中从醛14步(18.2%产率,85%DS)(已完成小号- )18。关键步骤包括:(i)(S)-18的不对称巴豆基硼酸酯化,得到均相醇15;(ii)由(S)-17产生的硼介导的醛14的醛醇缩醛结构;(iii)由Ba(OH)2促进的HWE反应,13 + 14→31;(四)在甲硅烷基烯醇醚33和醛11之间高度立体调节的穆山山醇醛偶联,得到加合物10 ; (v)酮10在C 17处的化学选择性还原,产生1,3-合成二醇34。