A Highly Efficient Strategy for One-Pot and Pseudo-Six-Component Synthesis of Hexahydroquinolines

In this study, a homogeneous acid-catalyzed reaction
of a series
of benzaldehydes, benzylamines, and Meldrum’s acid was presented,
allowing the novel one-pot and multicomponent synthesis of hexahydroquinolines
with high stereoselectivity. The current strategy has advantages including
high regioselectivity, good efficiency, reasonable diversity, utilization
of an inexpensive and safe catalyst, and easy purification of products
by simple recrystallization. The current reaction utilizes 2 equiv
of Meldrum’s acid, 3 equiv of benzaldehyde derivatives, and
one equiv of amine derivatives to yield (4’S,5′S,7’S)-1′-benzyl-2,2-dimethyl-4′,5′,7′-triphenyl-3′,4′,7′,8′-tetrahydro-1′H-spiro[[1,3]dioxane-5,6′-quinoline]-2′,4,6(5′H)-trione derivatives.