A chiral titanium complex, Ti(O-
i-Pr)
4/BINOL/
tert-butylcatechol, catalyzes enantioselective addition reaction of ketene silyl acetals to nitrones to give optically active
-amino acid derivatives which are biologically active compounds and useful synthetic intermediates of natural products and pharmaceuticals such as
-lactam antibiotics. The combined process of catalytic oxidation of secondary amines and enantioselective carbon-carbon bond formation of nitrones thus obtained with ketene silyl acetals provides a useful two-step method for the synthesis of optically active
-amino acid derivatives and related nitrogen compounds.