Intramolecular Michael-type additions. IV. Synthesis of 2-azabicyclo[3.2.1]oct-3-enes from 4-chloroalkyl-1,4-dihydropyridines

Abstract

2-Azabicyclo[3.2.1]oct-3-enes, including examples having a spiro centre at C(8), may be obtained by the reaction of anions derived from 1,3-diketones or cyclopentadiene with 4-chloroalkyl-1,4-dihydropyridines or with azepines. Intermediate 4,5-dihydro-1H-azepines have been isolated under milder conditions. The structures of the bicyclic compounds were established using infrared, ultraviolet, nuclear magnetic resonance, and mass spectrometry. Pharmacological examination of selected compounds revealed low antimicrobial and hypotensive activity.