Structure of showdomycin: X-ray analysis of N-methylbisdeoxocycloshowdomycin acetonide hydrobromide

Abstract

The crystal structure of N-methylbisdeoxocycloshowdomycin acetonide hydrobromide was determined by three-dimensional X-ray diffraction methods. The crystals are monoclinic, space-group P2₁, with Z= 2 for a unit cell of dimensions a= 11·01, b= 7·17, c= 10·98 Å, β= 118°45′. The structure was solved by heavy-atom and three-dimensional Fourier methods, and refined by least-squares calculations to final R of 0·076 for 723 independent reflexions. The absolute configuration was determined by the anomalous dispersion method.