SYNTHESIS OF DEMETHYL DERIVATIVES OF ISTAMYCIN A

Abstract

4-N, 6'-N, 3-O-Tridemethylistamycin A₀ (9) and 6'-N, 3-O-didemethylistamycin A₀ (15)
were synthesized from 3, 2', 6'-tri-N-benzyloxycarbonyl-3', 4'-dideoxyneamine 1, 6-carbamate
(1) through an aziridine derivative 6 by an analogous procedure employed in the total synthesis
of istamycin A₀ (19). Acylation of 15 with glycine at the 4-methylamino group gave 6'-N, 3-Odidemethylistamycin
A (18) having interesting activities especially against pseudomonas, but
4-N, 6'-N, 3-O-tridemethylistamycin A (12) derived from 9 showed only weak activity. Therefore,
the 4-N-methyl group of istamycin A (20) is essential for the antimicrobial activity.