Structure of buxenine-G. X-ray diffraction studies of buxenine-G dihydrobromide and dihydroiodide

Abstract

The crystal structures of the dihydrobromide and dihydroiodide of the novel Buxus alkaloid buxenine-G, C₂₅H₄₂N₂, have been determined, and the results establish that ring A of the steroidal alkaloid adopts the chair conformation of a cyclohexane and ring C the half-chair conformation characteristic of a cyclohexene. The dihydroiodide crystallizes in the orthorhombic space group P2₁2₁2₁ with a= 13·32 ± 0·02, b= 30·65 ± 0·03, c= 6·96 ± 0·01 Å, and Z= 4, and the dihydrobromide crystallizes in the monoclinic space group P2₁, with a= 11·012 ± 0·005, b= 7·556 ± 0·004, c= 32·816 ± 0·013 Å, β= 89·8 ± 0·1°, and Z= 4.