Studies of enzyme-mediated reactions. Part VII. Stereospecific syntheses of tritium-labelled (2R)- and (2S)-dopamines: stereochemical course of hydroxylation of dopamine by dopamine β-hydroxylase (E.C. 1.14.17.1)

An efficient synthesis has been developed for the preparation in high configurational purity of dopamines (3,4-di-hydroxyphenethylamines) stereospecifically labelled at C-2 with isotopes of hydrogen. By incubating (2R)-, and (2S)-[2-2H1]dopamines with dopamine β-hydroxylase (E.C. 1.14.17.1) it has been shown that the pro-R-hydrogen atom is lost in the formation of noradrenaline; thus the hydroxylation of the benzylic methylene group occurs with retention of configuration.