for the following products
(4S,5R)-2-(4-methoxyphenyl)-4-phenyl-3,5-oxazolidinedicarboxylic acid 3-(1,1-dimethylethyl)ester | (4S,5R)-3-(N-Boc)-2-(4-anisyl)-4-phenyl-5-oxazolidin carboxylic acid | (4S,5R)-3-(tert-Butoxycarbonyl)-2-(4-methoxyphenyl)-4-phenyl-1,3-oxazolidine-5-carboxylic acid and (4S,5R)-3-tert-Butoxycarbonyl-2-(4-anisyl)-4-phenyl-5-oxazolidinecarboxylic acid
