SYNTHETIC STUDIES ON DIAZONAMIDE .A. BENZOFURANONE-TYROSINE AND INDOLE-OXAZOLE FRAGMENT SUPPORT STUDIES

This paper discloses efforts toward the total synthesis of the marine natural product cytotoxin diazonamide A. Specifically addressed are ef ficient procedures for the synthesis of suitably substituted benzofura none and indole systems (C10-C17 and C18-C25 of the final product, res pectively). In addition, methods for incorporation of the tyrosine res idue, acylation of C10, elaboration of the C16-C18 biaryl bond, and fo rmation of the oxazole ring comprising C26-C28 have been explored.