An expedient pseudo four-component synthesis of dispiroindandione fused indeno-N-methylmorpholine, spectroscopic, X-ray diffraction and DFT studies

Synthesis of a novel heterocycle comprising N-methylmorpholine, spiroindandione and indenone units in good yield via one-pot pseudo four-component cascade cycloaddition reaction is described. The structure of the cycloadduct was elucidated by spectroscopic analysis and its complete stereochemistry was assigned by single crystal X-ray diffraction analysis. Further, the mechanistic rationalization for the formation of the hitherto unexpected cycloadduct is provided by performing density functional theory (DFT) calculations.