The preparation of 3-(3, 4-methylenedioxyphenyl)-D-, and -L-alanine (D-and L-(V)) was carried out by the chemical or biological resolution of N-acety1-3-(3, 4-methylenedioxyphenyl)-DL-alanine (DL-(IV)). The N-acetyl-DL-amino acid prepared from 3, 4-methylenedioxybenzyl chloride (H) and diethyl acetamidomalonate (I), via the diester (III), was resolved into two forms, D-and L-(IV), by means of fractional recrystallization of their cinchonine salts from ethanol, followed by the liberation of cinchonine base. Asymmetric hydrolysis of DL-(W) was also smoothly effected by Takadiastase to give the L-amino acid (L-(V)) and N-acetyl-D-amino acid (D-(W)). The latter as well as the one derived from the chemical resolution was converted by boiling it with 10% hydrochloric acid into the D-amino acid (D-(V)) in good yield.