STUDIES ON MACROCYCLIC LACTONE ANTIBIOTICS

VIII. ABSOLUTE STRUCTURES OF RHIZOXIN AND A RELATED COMPOUND

Abstract

The absolute structure of rhizoxin (1), a potent antifungal and antitumor antibiotic, was determined by interrelation with compound 2 whose structure was established by X-ray analysis. Since a ¹⁸OH group was introduced at C-3 on a hydrolytic cleavage of C-2, C-3 epoxy group with alkaline H₂¹⁸O, the original epoxy oxygen should be retained at C-2. The stereo-chemistry at C-2 and C-3 positions in rhizoxin was, therefore, determined as 2R, 3S.