CHIRAL LIGANDS CONTAINING HETEROATOMS .11. OPTICALLY-ACTIVE 2-HYDROXYMETHYL PIPERAZINES AS CATALYSTS IN THE ENANTIOSELECTIVE ADDITION OF DIETHYLZINC TO BENZALDEHYDE

Starting from enantiomerically pure serine, a series of (2R,5S) and (2 S,5S)-2-hydroxymethyl-5-alkyl piperazines 1-5 were prepared in good yi elds without any racemization. The use of these compounds as chiral ca talysts for the enantioselective addition of diethylzinc to aldehydes is described. This paper reports the first example of the use of piper azine methanols in asymmetric synthesis.