The novel diterpenoid taxol isolated from the western yew Taxus brevifolia is one of the most important lead compounds to emerge from the search for anticancer agents from plants. It shows consistent clinical activity against ovarian cancer and may also be active against other cancers. In this study, the preparation of various taxol derivatives was investigated, with the objective of better understanding the structural requirements for activity in the taxol series. The 7-hydroxyl group of taxol was derivatized with a photoaffinity label and other reagents as a beginning of the project to understand the interaction of taxol and tubulin, and the activity of all the derivatives in a tubulin assay was determined. A study of the deacylation and reacylation reactions of baccatin 111 was carried out in order to find conditions suitable for the preparation of 2-debenzoylbaccatin Ill , and thus 2-debenzoyltaxol. Finally, the reactions of taxol with various electrophilic reagents were investigated, and the structures of products with an opened oxetane ring and/or contracted ring A were determined. Biological assay results are reported on many of the compounds in this investigation. / Ph. D.