Synthesis of 7,9,10,11-tetrahydro-8 H-chromeno[3,2- h]quinolin-8-ones.

The article offers information on synthesis of tetrahydro-8 H-chromeno[3,2- h]quinolin-8-ones conducted by the authors. It states that the reaction of the Mannich base with the enamines 2a,b is a tandem process that includes formation of o-quinone methide from the Mannich base. It mentions that infra-red (IR) spectra of compounds 3a,b revealed absorption bands corresponding to the stretching of a carbonyl group.