STEREOSPECIFIC SYNTHESIS OF ALPHA-DEUTERIATED ALPHA-AMINO-ACIDS - REGIOSPECIFIC DEUTERIATION OF CHIRAL 3-ISOPROPYL-2,5-DIMETHOXY-3,6-DIHYDROPYRAZINES

Base-catalysed deuteriation of (3R)- or 3S)-3-isopropyl-2.5-dimethoxy- 3,6-dihydropyrazines in refluxing (CH3OH)-H-2-(H2O)-H-2 gives the [6-H -2(2)]-isotopomer in excellent yields without disturbing the stereogen ic centre at C-3. These compounds provide convenient and efficient acc ess to a range of (R)- and (S)-alpha-deuteriated alpha-amino acids, in cluding serine, aspartic acid, allylglycine and phenylalanine, via alk ylation of the butyllithium generated C-6 anion.