SYNTHESIS OF L-CANALINE AND GAMMA-FUNCTIONAL 2-AMINOBUTYRIC ACID-DERIVATIVES

The convergent synthesis of L-canaline (1) from L-homoserine (3) or L-methionine by the common intermediate 2-[(benzyloxycarbonyl)amino]-L-4-butyrolactone 5a is described. Functional group protection of L-homoserine (3) is examined, and procedures are reported which overcome the tendency for lactone formation, to provide protected 2-amino-4-hydroxybutyric acid derivatives with .gamma.-hydroxyl groups which are suitable for further .gamma.-functionalization.