CONVENIENT SYNTHESIS OF N-BENZYL-1,4-DIHYDROPYRIDINES, CYCLOHEXENONES, AND BICYCLO[3.3.1]NONAN-3-ONE DERIVATIVES FROM 1-AZA-1,3-BUTADIENES

Readily available 1-aza-1,3-butadienes (enimines) react with methyl ac etoacetate and acetylacetone in the presence of catalytic amounts of l ithium iodide to form in high yields unsymmetrically substituted 1,4-d ihydropyridines or cyclohexenones. The reaction pathway depends on the structure of the enimine used. This divergence was not observed when the enimines were reacted with dimethyl 1,3-acetonedicarboxylate to pr ovide bicyclo[3.3.1]nonane-3-one derivatives in excellent yields in a remarkably stereoselective reaction.