(R)-(+)-3-Amino-2-phenylpropanoic acid: a revised absolute configuration based on an enantioselective synthesis and an X-ray crystal structure of the salt with (1S)-(+)-camphor-10-sulfonic acid
Abstract
Amidoalkylation of the lithium enolate of (4S,5R)-4-methyl-5-phenyl-3-(phenylacetyl)oxazolidin-2-one 5 by 1-(N-benzyloxycarbonylaminomethyl)benzotriazole 2c, followed by cleavage of the oxazolidinone chiral auxiliary and of the N-benzyloxycarbonyl group, gave (R)-(+)-3-amino-2-phenylpropanoic acid 1, the absolute configuration of which was determined by X-ray crystallography on the salt 8 with (1S)-(+)-camphor-10-sulfonic acid.