ASYMMETRIC-SYNTHESIS OF SUBSTITUTED 1-AMINOCYCLOPROPANE-1-CARBOXYLIC ACIDS FROM A NEW CHIRAL GLYCINE EQUIVALENT WITH 3,6-DIHYDRO-2H-1,4-OXAZIN-2-ONE STRUCTURE

Condensation of the new chiral glycine equivalent 10 with aldehydes at room temperature in the presence of K2CO3 under solid-liquid phase-tr ansfer-catalysed conditions afforded stereoselectively new chiral (Z)- alpha,beta-didehydroamino acid (DDAA) derivatives with oxazinone struc ture 14. These systems have been used in diastereoselective cyclopropa nation reactions for the synthesis of enantiomerically pure 1-aminocyc lopropanecarboxylic acids (ACCs) such as (-)-allo-norcoronamic and (-) -allo-coronamic acids. (C) 1998 Elsevier Science Ltd. All rights reser ved.