Synthesis of Enantiopure syn-β-Amino Alcohols. A Simple Case of Chelation-Controlled Additions of Diethylzinc to α-(Dibenzylamino) Aldehydes

摘要

Enantiomerically pure syn-2-ammo alcohols 6 are prepared by addition of diethylzinc to chiral α-(dibenzylamino) aldehydes 4. The addition is highly stereoselective, leading to syn-2-(dibenzyl-amino) alcohols 5 with excellent diastereomeric excesses (76-98%). Debenzylation of 5 by hydrogenolysis on Pearlman's catalyst yields quantitatively the amino alcohols 6.