Synthesis of the <i>d</i>- and <i>l</i>-3: 4-dihydroxyphenylalanines

Abstract

ALTHOUGH dl-3: 4-dihydroxyphenylalanine has been synthesised on several occasions [Funk, 1911; Stephen and Weizmann, 1914; Harington and McCart- ney, 19271, the optically active forms of this amino-acid have not so far been artificially obtained. 1-3: 4-Dihydroxyphenylalanine was first isolated by Guggenheim [1913] from Viciafaba; renewed biological interest attaches to this amino-acid as the result of the recent work of Raper [1926], who has shown that it represents the first stage in the formation of melanin from tyrosine by the enzyme tyrosinase. It therefore appeared to us desirable to complete the synthesis of 1-3: 4-dihydroxyphenylalanine by resolution of the dl-amino-acid into its optically active components.