Synthesis of a new heterocyclic ring system 2,3,5,6,7,9,10,11-octahydro-lH-cyclopenta[9,H)]benzo[i,j] quinolizine-1,9-dione

Abstract

Reaction of 1,2,3,4-tetrahydroquinoline (1) with different, α,β-unsaturated acids in the presence of PPA has been investigated. With acrylic acid, 1 affords two compounds identified as 1-keto-benzo[i,j]quinolizine (III) and 2,3,5,6,7,9,10,1 1-octahy dro-1H-cy el open ta [9,10] benzo [i,j]-quinolizine-1,9-dione (IV). A similar reaction of 1 with a-methyl acrylic and crotonie acids gives compounds V and VI whose structures are analogous to that of IV. These were deduced from their spectral and analytical data.