SYNTHESIS OF PIPECOLIC ACID-DERIVATIVES BY AZA-DIELS-ALDER REACTION - ZINC IODIDE ACTIVATED CYCLOADDITIONS BETWEEN THE 1-(PHENYL)-ETHYLIMINE OF METHYL GLYOXYLATE AND ELECTRON-RICH DIENES
The methyl N-(1-phenylethyl)-alpha-iminoacetate undergoes zinc iodide activated aza-Diels-Alder cycloaddition reactions with electron rich conjugated dienes. Cyclic alpha-amino-acids are formed in good yields, with complete regioselectivity, but the extent of asymmetric induction by the chiral phenethyl group on the nitrogen is low.