The new chiral glycine equivalent 9, easily obtained from(+)-alpha-aminoisovalerophenone and glycine, afforded chiral (Z)-alpha,beta-didehydroamino acid (DDAA) derivatives 13 and 14 with a 1,2,3,6-tetrahydropyrazin-2-one structure. Compounds 13 and 14 were synthesised by reaction of 9 with Eschenmoser's salt and by condensation reactions with aldehydes or acetone under PTC conditions, respectively. The diastereoselective cyclopropanation of 14, followed by hydrolysis, furnished (-)-allo-norcoronamic acid with high ee, whilst diastereoselective Diels-Alder reaction of dienophile 13 and cyclopentadiene afforded, after double bond hydrogenation and hydrolysis, (-)-2-aminonorbornane-2-carboxylic acid. (C) 2000 Elsevier Science Ltd. All rights reserved.