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

•Synthesis of hitherto unreported morpholine fused unusual spiroheterocyle.•Product achieved in good yield via one-pot cascade reaction sequence.•The structure determined by spectral and single crystal X-ray diffraction studies.•Formation of spiroheterocyle has been investigated through DFT calculation.

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.

Graphical abstractSynthesis of hitherto unexpected N-methylmorpholine fused spiroheterocycle has been accomplished in good yield via one-pot pseudo four component cascade cycloaddition reaction and its stereochemistry was assigned by single crystal X-ray diffraction analysis. The mechanistic rationalization for the formation of unusual cycloadduct was investigated through density functional theory (DFT) calculations.Figure optionsDownload full-size imageDownload as PowerPoint slide