A variety of steroids and sesquiterpenes have been found to possess anti-tumor activity. The variation in structure of possible analogs of these biologically active materials has been limited to variations of available natural material. The present project will be directed towards total synthesis of the basic structures which, in turn, will permit a wider variety of modified agents to be prepared. The proposed steroid research has as its basis the preparation of the fusidic acid and the shionone ring systems. These materials can be viewed as possessing a "delayed" delivery structure and a variety of derivatives will be prepared. The proposed sesquiterpene research has as its basis the synthesis of compounds related to the anti-tumor lactone, vernolepin. The general eudalene nucleus possessing the requisite functionalities will be prepared and a structure activity relationship in this lactone series will be obtained.