Studies in olefin cyclisation

• Main Author: Solomon, Malcolm David
• Published: Imperial College London 1967
• Subjects: 547
• Online Access: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.622968

This thesis, which is divided into three main sections, deals mainly with the transannular cyclisation reactions of some alicyclic dienes. In the first part of the thesis, the synthesis and cyclisation reactions of germacrene, a possible intermediate in the biosynthesis of certain classes of sesquiterpene, are described. Germacrene, a cyclodecane sesquiterpene, can be converted to sesquiterpenes of the selinane and elemane types. The second section is concerned with the related medium-ring sesquiterpenes, humulene and caryophyllene. The mechanisms of the formation and decyclisation of some tricyclic humulene derivatives are discussed. Also described are the reduction reactions of two brominated humulene derivatives, and some attempts to convert caryophyllene to humulene. Finally, a new method for the preparation of 1,4-dienes by the lithium in liquid ammonia reduction of suitable acetoxy-dienes is described. 1,4-Dienes fulfilling certain geometrical requirements give the product of honoconjugate 1,5-addition on treatment with bromine or hypobromous acid.