2-tetrahydropyranylmethylester of L-3,4-dihydroxyphenylalanine

phenoxyethyl ester of L-3,4-dihydroxyphenylalanine

p-methoxyphenylethyl ester of L-3,4-dihydroxyphenylalanine

L-DOPA tert-butyl ester

(S)-methyl 2-(4-(3,4-dihydroxybenzyl)-2,2-dimethyl-5-oxoimidazolidin-1-yl)acetate