Advances in terpene chemistry

Abstract

In the first part of the lecture some new advances in the chemistry of sesquiterpenic lactones are discussed and the revised structures of some cmaianolides and germacranolides are presented. The second part is devoted to the chemistry of sesquiterpenic compounds of eremophilane type, met by the author and his collaborators repeatedly during the study of the plants of Petasites species and related plants. In addition to the basic hydrocarbon eremophilen.e a series of lactonic compounds was also isolated from the mentioned plants, to which the name eremophilanolides was given and which represent a new group of sesquiterpenic lactones. The most common natural derivatives of the eremophilane series are however furoeremophilanes. In addition to the free furoeremophilane an appreciable number of hydroxy-and keto-derivatives substituted predominantly in positions 3, 6 and 9 of the eremophilane nucleus, saturated and unsaturated and containing free or esterified hydroxy groups, has been isolated from plants. In the lecture the chemistry of these compounds is discussed, mainly those isolated recently, as for example adenostylone, neoadenostvlone, isoadenostvlone and kablicin. Finally, possible biogenetical pathways of the sesquiterpenic lactones from the corresponding furan derivatives are also discussed. © 1970, Walter de Gruyter. All rights reserved.