An amino group of an &agr;-amino acid ester is protected as an imine, and it is then reacted with a halomethyllithium to obtain an N-protected-&agr;-aminohalomethylketone. Further, this N-protected-&agr;-aminohalomethylketone is treated with an acid to obtain an &agr;-aminohalomethylketone. This process is suited for industrial production, and can produce an &agr;-aminohalomethylketone and its related compounds economically and efficiently.
An amino group of an &agr;-amino acid ester is protected as an imine, and it is then reacted with a halomethyllithium to obtain an N-protected-&agr;-aminohalomethylketone. Further, this N-protected-&agr;-aminohalomethylketone is treated with an acid to obtain an &agr;-aminohalomethylketone. This process is suited for industrial production, and can produce an &agr;-aminohalomethylketone and its related compounds economically and efficiently.
Dihalomethylation of several N-protected amino acid esters gave N-protected alpha -aminoalkyl-alpha ' -dihalomethylketones, which are useful intermediates for the synthesis of erythro P-amino-a-hydroxycarboxylic acids, in good yield. The dihalomethylketones were successfully converted to N-protected alpha -aminoalkyl-alpha ' -halomethylketones by selective catalytic hydrogenation. (C) 2001 Elsevier Science Ltd. All rights reserved.