29. Stereoselektive Synthese von optisch aktivem Vincamin
    Pfäffli, P.; Oppolzer, W.; Wenger, R.; Hauth, H.
    Helv. Chim. Acta 1975, 58, 1131-1145

Vincamine (13) was prepared from the aldehyde 8 in 5 steps using methyl dimethyl-phosphono-methoxy-acetate as a synthon for the pyruvic ester residue. A method to convert apovincamine (12) into vincamine (13) has hen worked out. Optically active 8 was synthesized from ethyl-malonaldehydic acid ethyl ester in 9 steps including optical revolution of the acid intermediate 3 by means of salt formation with L-(+)-pseudoephedrine. The two diastereomeric salts were distinguishable by NMR. in carbontetrachloride.

DOI : 10.1002/hlca.19750580416