Absolute configuration of mesembrine and related alkaloids: X-ray analysis of 6-epimesembranol methiodide

Abstract

X-Ray crystal-structure analysis has established the conformation and absolute configuration of 6-epimesembranol methiodide (IV). the crystals are monoclinic, space group P2₁, with Z= 2, and cell dimensions a= 9·12, b= 8·50, c= 12·25 Å, β= 93·7°. Atomic co-ordinates were obtained by Fourier methods and refined by full-matrix least-squares calculations; the final value of R is 0·106 for 1748 independent reflexions.