Total synthesis of FK-506. Part 1: Construction of the C16–C34 fragment
作者:Robert E Ireland、Longbin Liu、Thomas D Roper
DOI:10.1016/s0040-4020(97)00865-x
日期:1997.9
catalyzed carboalumination - in situ transmetalation with a higher order cuprate, followed by stereoselective conjugate addition to a spiroenone. The C27–C28 tri-substituted olefin was formed either via coupling of a methyl cuprate with an enoltriflate, mediated by sonication, or via direct coupling between the C17-aldehyde and the C28-vinyl magnesium bromide.
C23–C27 1,3-二醇是通过Brown的crotylation-osmylation或区域和D-xylofuranose衍生的2,3-anhydro-β-rifurfuranoside的立体选择性开口而构建的。路易斯酸用受保护的硫代糠醛醇催化环氧化物开环,然后氧化螺环缩酮化,将C21–C24螺缩酮建立为掩蔽的α'-烯丙基醛醇。C19-C20三取代的烯烃是通过锆催化的碳铝化反应合成的-用较高级的铜酸盐原位进行金属转移,然后将立体选择性的共轭物加成螺碳烯酮。C27-C28三取代烯烃是通过将铜酸甲酯与烯醇三酯偶联(通过声波作用)或通过C17-醛与C28-乙烯基溴化镁之间的直接偶联而形成的。