Azabicyclic amino acids by stereoselective dearomatizing cyclization of the enolates of N-nicotinoyl glycine derivatives

[GRAPHICS] On activation by pyridine N-acylation, enolates of N-nicotinoyl and N-isonicotinoyl glycine and alanine derivatives cyclize to yield 6,5-azabicyclic or 6,4-azaspirocyclic lactams. With an N-r-methyl-p-methoxybenzyl group the cyclization is diastereoselective; hydrogenation and deprotection yields azabicyclic amino acids in 94:6 er.