Deuteriation and tritiation of aryl aldehydes in the formyl group and the synthesis of (+-)-3,4-dihydroxy ) 7β-2H2{ phenylalanine. )]

Aryl aldehydes have been converted into the corresponding α-aryl-α-morpholinoacetonitriles and thence, by treatment with base, into the derived benzylic anions. Quenching of these anions with deuterium oxide or tritiated water, followed by hydrolysis with mineral acid, gave formly-labelled aldehydes. [formyl-2H]-3,4-Dimethoxy-benzaldehyde gave, when heated with alkali, [methylene-2H2]-3,4-dimethoxybenzyl alcohol, a convenient starting material for the synthesis of (±)-3,4-dihydroxy[β-2H2]phenylalanine.