Studies on the Synthesis of (−)-Spinosyn A: Application of the Steric Directing Group Strategy to Transannular Diels−Alder Reactions
作者:Scott A. Frank、William R. Roush
DOI:10.1021/jo025580s
日期:2002.6.1
highly diastereoselective and enantioselective synthesis of the decahydro-as-indacene nucleus 12 of (-)-spinosyn A (1) is reported. By implementing the steric directing group strategy, tricyclic lactone 37 was produced from a remarkably diastereoselective transannular Diels-Alder reaction of lactone 9. The tricyclic core of the natural product was then obtained by using an Ireland-Claisen ring contraction
据报道,(-)-多杀菌素A(1)的十氢化物为茚并二烯核12的高度非对映选择性和对映选择性合成。通过实施空间方向群策略,由内酯9的非对映选择性的跨环Diels-Alder反应产生了三环内酯37。然后,使用Ireland-Claisen环收缩37获得了天然产物的三环核。这两个步骤的顺序导致非对映选择性几乎完全丧失。