An efficient one-pot synthesis of spiro dihydrofuran fluorene and spiro 2-hydroxytetrahydrofuran fluorene derivatives via [3+2] oxidative cycloaddition mediated by CAN

Spiro dihydrofuran fluorene derivatives were prepared via [3+2] oxidative cycloaddition of 1,3-dicarbonyl compounds to 9-benzylidene-9H-fluorene and 2-(9H-fluorene-9-ylidene)-1-phenylethanone derivatives mediated by ceric ammonium nitrate. In the case of the reaction of 9-benzylidene-9H-fluorene with acyclic 1,3-dicarbonyl compounds, spiro 2-hydroxytetrahydrofuran fluorene derivatives were obtained.