SYNTHESIS OF GAMMA-OXO ALPHA-AMINO-ACIDS FROM L-ASPARTIC ACID

The synthesis of different gamma-oxo alpha-amino acids from hexafluoro acetone protected L-aspartic acid chloride 1 via Stille cross coupling reaction is described. Stille reaction of 1 with vinyltributyltin fol lowed by Lewis acid catalyzed intramolecular Michael addition provides access to 4-substituted pipecolic acid derivatives. An efficient synt hesis of 5-hydroxy-4-oxo-L-norvaline 7 and a new approach to the 4-oxo -L-ornithine skeleton starting from 1 have been elaborated. Copyright (C) 1996 Elsevier Science Ltd