Alkaloids of Physostigma venenosum Part IX. The absolute configuration of geneserine; an application of the nuclear overhauser effect

Abstract

Investigation of geneserine by use of the nuclear Overhauser technique has shown that the junction between the pyrrolidine and tetrahydro-1,2-oxazine rings is cis-fused and that at a temperature of 20° the N(1)-methyl group and the C(2)-proton of the indoline system are predominantly in a cis relationship. Since the absolute configuration at the indoline 3-carbon atom is already known, the absolute stereochemistry of the alkaloid is established.