Structural studies of bicyclomycin

Abstract

The complete 1H and 13C nmr assignments for both bicyclomycin (1) and bicyclomycin‐3′‐ethyl carbamate (2) were achieved through the combined use of a series of nmr techniques. Extensive use of the long range heteronuclear multiple quantum chemical shift correlation experiment (HMBC) permitted the assignments of all the exchangeable protons as well as the 2,5‐piperazinedione carbonyl carbons in both compounds. The X‐ray crystallographic structure of 2 was determined and compared to the reported structure of bicyclomycin. Compound 2 crystallizes in the orthorhombic space group P212121 with four molecules in a unit cell having dimensions a = 7.931(2), b = 10.834(4), and c = 24.468(7) Å. The structure refined to a final R value of 6.2%. Copyright © 1988 Journal of Heterocyclic Chemistry