Ketone 9 was synthesized in 7 steps from commercially available 2-methylcyclohexane-1,3-dione in a diastereoselective fashion. Shapiro reaction of easily available trisylhydrazone 11 with benzaldehyde was used as a model for A- and C-ring coupling. Finally, reaction of trisylhydrazone 24 with A-ring aldehyde 4, under carefully controlled conditions, gave seco-taxane 27 with high diastereoselectivity for the diol moiety.
酮 9 是以非对映选择性方式,通过 7 个步骤从市售的 2-
甲基环己烷-1,3-二酮合成的。利用容易获得的三基氢腙 11 与
苯甲醛的 Shapiro 反应作为 A 环和 C 环偶联的模型。最后,在严格控制的条件下,三苯基腙 24 与 A 环醛 4 反应生成了仲
对二甲苯 27,二醇分子具有很高的非对映选择性。