The reactions with aldehydes of enaminones derived from dimedone

Abstract

The primary and a secondary enaminone derived from dimedone react with formaldehyde to give the expected methylenebisenaminone derivatives (V). Depending upon the conditions, further reactions can take place to give 3,4,5,6,9,10-hexahydro-3,3,6,6-tetramethylacridine-1(2H),8(7H)-diones (VI) or 1,2,3,4,7,8-hexahydro-4′,4′,7,7-tetramethylquinoline-3-spirocyclohexane-2′,5(6H),6′-triones (VII). The corresponding reaction with benzaldehyde gives only the decahydroacridinedione (VId); that with acetaldehyde gives either the decahydro-acridinedione (VIc) or 1,2,7,8-tetrahydro-2,4,7,7-tetramethyl-4H-3,1-benzoxazin-5(6H)-one (XI).