Syntheses of 1, 3, 4, 6, 11, 11a-Hexahydro-2H-benzo[b]quinolizine Derivatives

Abstract

Phenyl-α-pyridylcarbinol compounds (VIII and IX), possessing substituents in the 3- and 4-positions of the benzene ring, were synthesised by the Hammick reaction of picolinic acid, piperonal, and veratraldehyde. Their reduction to the α-benzyl-piperidine compounds (XII and XIII), formylation by heating with fomic acid, dehydrative cyclization with phosphoryl chloride, and reduction with zinc and hydrochloric acid afforded 8, 9-methylenedioxy- (XIV) and 8, 9-dimethoxy-1, 3, 4, 6, 11, 11a-hexahydro-2H-benzo [b] quinolizine (XV).