UNUSUAL AMINO ACIDS. IV. ASYMMETRIC SYNTHESIS OF THIENYLALANINES

Article abstract of DOI:10.1016/S0957-4166(00)80424-3

(Z)-2-N-Acylamino-3-thienyl-acrylic acids and thei esters were prepared by known procedures and hydrogenated to the corresponding optically active 2-N-acetyl(or benzoyl)-3-(2- or 3-thienyl)-alanines with optically yields up to 90percent using the rhodium complexes of 'PROPRAPHOS" 6a,b and O,N-bis(diphenylphosphino)-2-exo-hydroxy,3-endo-methylamino-norbornane 6c as chiral catalysts.Recrystallization and deacylation of the obtained amino acid derivatives yields the optically pure hydrochlorides of the thienylalanines as the free amino acids.