Total syntheses of pamamycin 607 and methyl nonactate: stereoselective cyclisation of homoallylic alcohols that had been prepared with remote stereocontrol using allylstannanes
作者:Olivier Germay、Naresh Kumar、Christopher G. Moore、Eric J. Thomas
DOI:10.1039/c2ob26801a
日期:——
then replaced by an N-(tert-butoxycarbonyl) group and O-debenzylation and oxidation gave the carboxylic acid 70 that corresponds to the C(1)–C(18) fragment of pamamycin 607 (1). Similar chemistry was used to prepare the C(1′)–C(11′) fragment 89 of the pamamycin, except that in this case the configuration of the secondary alcohol introduced by the allylstannane reaction had to be inverted using a Mitsunobu
发现在路易斯酸存在下,使用苯基硒烯基氯或邻苯二甲酰亚胺,由氯化锡(IV)介导的(Z)-均烯丙基醇的环化反应,然后还原性去除苯基硒烯基,可得到具有优异立体控制的2,5-顺式-二取代四氢呋喃。 。使用该程序,通过锡(IV)立体选择性地制备了(2 S,4 S,8 R,6 Z)-9-苄氧基-2-叔丁基二苯基甲硅烷基氧基-8-甲基非-6-烯-4-醇(11))之间的氯化物促进反应(R)-5-苄氧基-4-甲基戊-2-烯基(三丁基)锡烷(3)和(S)-3-叔丁基二苯基甲硅烷基氧基丁醛(10),得到(2 S,3 R,6 S,8 S)-1脱硒后的-苄氧基-8-叔丁基二苯基甲硅烷氧基-3,6-环氧-2-甲基壬烷(13)。将该四氢呋喃选择性地脱保护,氧化和酯化,得到非乳酸甲酯(2)。已经建立了2,5-顺式-二取代的四氢呋喃的这种合成,将其用于完成帕马霉素607(1)的合成。(2 S,3 R从(R)立体选择性地制备,6S,8R)-1-苄氧基-8-