An approach to the synthesis of gelsemine: the intramolecular reaction of an allylsilane with an acyliminium ion for the synthesis of one of the quaternary centres
作者:Carol Clarke、Ian Fleming、Joseph M.D. Fortunak、Peter T. Gallagher、Matthew C. Honan、André Mann、Christoph O. Nübling、Paul R. Raithby、J.Jens Wolff
DOI:10.1016/s0040-4020(01)86646-1
日期:1988.1
steps in the synthesis are (i) the Diels-Alder reaction between 1-tetrahydropyranyloxycyclohexa-1,3-diene (10) and methyl β-nitroacrylate (11) giving an adduct (12), in which the chiral centre in the tetrahydropyranyl ring is produced substantially in only one sense, (ii) the rearrangement of a bicyclo [2.2.2] octane (23) into a bicyclo[ 3.2.1] octane (24), where control of which bridge migrates is
我们描述了适合合成明胶的高级中间体(34)的有效合成方法(在方案8和10中进行了概述)。合成中的关键步骤是(i)1-四氢吡喃基氧基环己-1,3-二烯(10)和β-硝基丙烯酸甲酯(11)之间的Diels-Alder反应,生成加合物(12),其中手性中心位于四氢吡喃基环基本上仅在一种意义上产生,(ii)将双环[2.2.2]辛烷(23)重排为双环[3.2.1]辛烷(24),其中通过路易斯酸中抗衡离子的选择,以及(iii)通过烯丙基硅烷基团和酰基亚胺离子之间的分子内反应有效形成季中心(33→34)。