Crystal and molecular structure of stemonine hydrobromide hemihydrate

Abstract

The crystal structure and absolute stereochemistry of stemonine hydrobromide hemihydrate, C₁₇H₂₅O₄N,HBr,½H₂O, have been determined by a single-crystal X-ray analysis. The crystals are orthorhombic, a= 17·781, b= 8·786, c= 11·859 Å, Z= 4, space group P2₁2₁2₁. The intensities were measured with a Hilger and Watts automatic four-circle diffractometer using Mo-K_α radiation. The structure was solved by the programme SEARCHER, for the automatic heavy-atom analysis, and refined by full-matrix least-squares calculations to a final R of 0·092 for 1436 independent observed reflexions. The absolute configuration was determined by consideration of anomalous dispersion effects. The skeleton of the molecule consists of two furan rings, a pyrrolidine, and an azepine ring.