Regioselective and diastereoselective synthesis of two functionalized 1,5-methanoindeno[1,2-d]azocines via a three-component reaction.

The morpholine promoted three-component reaction of N-alkylpiperidinone, indane-1,3-dione and 2-arylideneindane-1,3-dione in ethanol at room temperature resulted in the (1H-1,5-methanoindeno[1,2-d]azocin-12-ylidene)-1H-indene-1,3(2H)-dione derivatives in good yields and with exo-configuration. Under similar conditions, the reaction of N-alkylpiperidinone with 2-arylideneindane-1,3-dione afforded 7H-1,5-methanoindeno[1,2-d]azocine-7,12-diones with endo-configuration. The domino reaction is believed to proceed with domino Knoevenagel condensation, Michael addition and aldol condensation reaction.