Abstract
Structures of chicamycins A and B have been determined from a series of chemical degradation studies coupled with spectroscopic analysis. Chicamycin A is 2(S), 11(R), 11a(S)-1, 2, 3, 10, 11, 11a-hexahydro-2, 8-dihydroxy-7, 11-dimethoxy-5H-pyrrolo-[2, 1-c][1, 4]-benzodiazepin-5-one, and chicamycin B is 2(S), 11a(S)-1, 2, 3, 11a-tetrahydro-2, 8-dihydroxy-7-methoxy-5H-pyrrolo-[2, 1-c][1, 4]-benzodiazepin-5-one which is the demethanol form of chicamycin A. The structure of chicamycin B is closely related to that of neothramycin, differing only in the position of a hydroxyl substituent on the pyrrolidine ring.
