X-ray analysis of the structure and correlation with the spectra of haplophytine

Abstract

Haplophytine crystallizes as the methanolate in the orthorhombic space group P2 1 2 1 2 1 with a = 13.874(4), b = 10.628(4), c = 22.890(9) Å, Z = 4. X-Ray structure analysis confirms that the previously assigned structure 3 is correct and that haplophytine undergoes reversible rearrangement on conversion to its dihydrobromide 1. The dimensions of 3 provide evidence supporting previous interpretations of unusual features of the infrared and proton magnetic resonance spectra of haplophytine.