@article {48027, title = {Divergent annulation of spiro[indoline-pyran] and fused (Epoxyetheno)indeno-furan from 1,2-diketone and 1-cyanoketone}, journal = {European Journal of Organic Chemistry}, volume = {2022}, year = {2022}, month = {AUG}, pages = {e202101534}, type = {Article}, abstract = {

A simple and efficient method for the construction of spiro[indoline-pyran] and fused (epoxyetheno)indeno[1,2-b]furan compounds from 1-cyanoketones and 1,2-diketone has been developed. The synthesis proceeded via the Knoevenagel and Michael adduct through intramolecular/Paal-Knorr cyclization under similar reaction condition. The less commonly used 1-cyanoketones and active carbonyl compounds served as the indole containing pyran and bicyclic furan source for the preparation of a new series of heterocyclic compounds. This heterocyclic structure allows one and more than one tetra-substituted carbon center and sequential hexa- and penta-cyclic core under very mild conditions and shows excellent chemo and regioselectivity. In addition, the synthesis of spiro[indoline-pyran] and (epoxyetheno)indeno[1,2-b]furan was demonstrated in a gram scale.

}, keywords = {Diverse synthesis, Intramolecular, Knoevenagel and Michael adduct, molecular diversity, Oxygen heterocycles, Paal-Knorr cyclization}, issn = {1434-193X}, doi = {10.1002/ejoc.202101534}, author = {Yadav, Maruti B. and Vagh, Sandip S. and Jeong, Yeon Tae} }