INTRAMOLECULAR CYCLIZATION WITH OXOCARBENIUM ION - SYNTHESIS OF 1-AZABICYCLO[3.3.1]NONENE AND [3.2.1]OCTENE DERIVATIVES

Hydroxy- and aryl-substituted 1-azabicyclo[3.3.1]nonene and [3.2.1]oct ene derivatives have been synthesized by the intramolecular cationic c yclization of 4-aryl-1,2,5,6-tetrahydropyridines bearing an acetal moi ety in the nitrogen substituent. Factors governing the stereoselectivi ty of the ring closure step have been disclosed. Two compounds were re solved into the enantiomers and the absolute configuration of one of t hem was deduced from CD investigations. Among the new compounds substa nces with valuable antiamnesic effect have been found.