Studies on Orchidaceae Alkaloids. VI. Synthesis and Relative Configuration of 5,7-Dimethyloctahydroindolizines.

Abstract

The 4 racemates of 5,7-dimethyl-octahydroindolizine have been synthesized and their relative configuration assigned by NMR [nuclear magnetic resonance]- and IR-spectrometry. 5,7-cis-9-trans-5,7-Dimethyl-octahydroindolizine possessed properties identical with the alkaloid found in Dendrobium primulinum Lindl. The preferred conformations of the 4 racemates and the corresponding methiodides are discussed, as well as the position of the N-CH3 signal in the NMR-spectrum in view of the spatial relationships of the N-methyl group.