Lithium Perchlorate-, Acetic Anhydride-, and Triphenylphosphine-assisted Multicomponent Syntheses of 4-Unsubstituted 2,5-Dioxooctahydroquinoline-3-carboxylates and 3-carbonitriles.

Lithium perchlorate and acetic anhydride were the key additives for the multi-component reaction between 3-aminocyclohex-2-enones, formaldehyde, and malonates yielding adducts that were annulated under acidic conditions to afford bicyclic 2,5-dioxooctahydroquinoline-3-carboxylates. When methyl cyanoacetate was subjected to the same reaction conditions in the presence of a catalytic amount of triphenylphosphine, the bicyclic 2,5-dioxooctahydroquinoline-3-carbonitriles were obtained in a one-flask reaction.