Abstract
L-Phenylalanine was prepared by the catalytic reduction of O-tosyl-L-tyrosine with Raney nickel catalyst in alkaline medium. Any change of configuration did not occur. In the reaction mixture, some tyrosine, hydrolyzed product of the O-tosyl ester, can be detected. L-Phenylalanine was isolated from the reaction mixture by the treatment with a cation-exchange resin and the fractional crystallization. The yield of L-phenylalanine was about 55% of the theoretical amount.
The reduction of ditosyl-L-tyrosine gave N-tosyl-L-phenylalanine. An improved method for the preparation of O-tosyl-L-tyrosine is also reported.
