N-PHTHALIMIDOAZIRIDINES BY DIASTEREOSELECTIVE ADDITION TO ALPHA,BETA-UNSATURATED AMIDES - A ROUTE TO CHIRAL BETA-SUBSTITUTED ALPHA-HYDRAZINO ACID-DERIVATIVES
Lead tetraacetate oxidation of N-aminophthalimide 1 in the presence of N-enoylbornane[10,2]sultams (Oppolzer auxiliary) generates corresponding N-phthalimidoaziridine adducts (12-94% yield) with 33% to greater-than-or-equal-to 95% diastereofacial selectivity (syn attack at the re face of the alpha-carbon for 4a); these chiral N-aminoaziridine derivatives readily undergo ring opening by sulfur nucleophiles to give alpha-hydrazino acid derivatives.