Convenient synthesis of (S)-(+)-apomorphine from (R)-(-)-apomorphine

Article abstract of DOI:10.1002/jps.2600690918

A method was devised for preparing (S)-(+)-apomorphine from (R)-(-)-apomorphine. Dehydrogenation of the dimethyl ether of (R)-(-)-apomorphine with 10% palladium-on-carbon carbon followed by reduction with sodium cyanoborohydride under acidic conditions resulted in quantitative racemization to given (R,S)-apomorphine dimethyl ether, which then was resolved with (-)-tartaric acid. Ether cleavage of (S)-(+)-apomorphine dimethyl ether (-)-tartrate with hydriodic acid in acetic anhydride yielded (S)-(+)-apomorphine, which was isolated as the hydrochloride salt in 99% enantiomeric excess.