coupling reactions of α-(alkoxycarbonyl)amino ketones 1 and 3 with methyl, ethyl, isopropyl, and tert-butyl crotonate took place with high stereocontrol about the new chiral centers providing the syn-1,2-amino alcohol products, syn-trans-γ-lactones 2 and 4, in excellent yields. Apparently, the stereochemicalcourse of these reductive couplings is stereocontrolled by chelation of the Sm(III) cations