THE ABSOLUTE CONFIGURATION OF BERBERASTINE AND THALIDASTINE

Article abstract of DOI:10.1016/0040-4039(80)80166-3

Optical resolution of (+/-)-tetrahydrojatrorrhizine using (-)-O,O-di-p-toluoyl-d-tartaric acid gave rise to (+)-tetrahydrojatrorrhizine (6) of high optical purity and of known absolute configuration.Oxidation of this enantiomer with lead tetraacetate, followed by acid hydrolysis, furnished alcohols 10 and ll in a 2:1 ratio, whose relative stereochemistry was established from their nmr spectra.Iodine oxidation of the major alcohol 10 led to protoberberinium salt 14 which was found to be dextrorotatory.Since berberastine (1) and thalidastine (2) are also dextrorotatory, they must possess the same absolute configuration as 14.