The interaction of 2-chloroethyl chloromethyl ether (I) and the sodium salt of 2-phthalimidomalonate (II) in dimethylformamide afforded the condensation product (III). An amino group was then introduced to the latter compound by means of potassium phthalimide (A), giving (IV). The racemic amino acid (V) could be obtained on removal of the phthalyl groups by treatment with hydrazine. However, the racemic phthalimide compound (IV) could be used directly for resolution through the brucine salt, and the protecting groups were then removed by hydrolysis with 6N hydrochloric acid. The levo-amino acid (V) was finally isolated as the dihydrochloride.

The interaction of 2-chloroethyl chloromethyl ether (I) and the sodium salt of 2-phthalimidomalonate (II) in dimethylformamide afforded the condensation product (III). An amino group was then introduced to the latter compound by means of potassium phthalimide (A), giving (IV). The racemic amino acid (V) could be obtained on removal of the phthalyl groups by treatment with hydrazine. However, the racemic phthalimide compound (IV) could be used directly for resolution through the brucine salt, and the protecting groups were then removed by hydrolysis with 6N hydrochloric acid. The levo-amino acid (V) was finally isolated as the dihydrochloride.