General Methodology for the Topologically Selective Preparation of Linear and Nonlinear Tricyclopentanoids of Hirsutane and Isocomene Type<i>via</i>a Claisen Rearrangement / Cyclopentene Annulation Sequence. Total Synthesis of (±)- Epiisocomene
作者:Tomas Hudlicky、Lawrence D. Kwart、Mark H. Tiedje、Brindaban C. Ranu、Robert P. Short、James O. Frazier、H. Lee Rigby
DOI:10.1055/s-1986-31756
日期:——
The intramolecular cyclopentene annulation methodology which combines the cyclopropanation of dienic diazoketones and the vinylcyclopropane rearrangement is utilized to synthesize linear tricyclopentanoids of the hirsutane class or nonlinear members of the isocomene class. The requisite diene precursors, endocyclic or exocyclic, respectively, are obtained from acylcyclopentenes via orthoester Claisen rearrangement of either allyl or propargyl alcohols. The scope and the generality of the method are indicated and experimental details are presented pertaining to the synthesis of precursory dienes for hirsutane and isocomene sesquiterpenes. Full details are disclosed concerning the total synthesis of epiisocomene and the synthesis of linearly fused precursors to coriolin sesquiterpenes.
采用分子内环戊烯环化方法,结合二烯二氮酮的环丙烷化和乙烯基环丙烷的重排反应,用于合成线性三环环戊烷类的大毛蕨类化合物或非线性的异黄樟素类化合物。所需的二烯前体,无论是内环的还是外环的,分别通过酰基环戊烯经由烯丙基或炔丙基醇的正酯Claisen重排得到。该方法的适用范围和普适性被指出,并详细介绍了合成大毛蕨和异黄樟素倍半萜前体二烯的实验细节。关于epiisocomene的全合成和合成coriolin倍半萜线性融合前体的全部细节被详细披露。