Reactions of 1,5-diketones. 42. Synthesis of heterocycles by the reaction of 4,4-dimethyl-1-phenyl-1-(2′-oxocycloalkyl)-3-pentanones with nitrogen-containing nucleophiles

The reaction of 1,5-diketones containing a pivaloyl fragment with several nitrogen-containing nucleophiles was studied. Derivatives of 2-tert-butyl-1,4-dihydropyridine were obtained and the direction of heterocyclization upon the reaction of these diketones with primary amines containing an additional nucleophilic site was elucidated. The facile free-radical cleavage of the angular tert-butyl group was demonstrated.