Synthesis of 9-Aryl-9,10-dihydrophenanthrenes by Domino [3+3] Annulation/Ring-Opening/Friedel–Crafts Alkylation Reactions of 1,3-Bis(trimethylsilyloxy)-1,3-butadienes with 3-Aroyl-5-aryl-4,5-dihydrofurans

The reaction of 1,3-bis(trimethylsilyloxy)-1,3-butadienes with 3-benzoyl-5-aryl-4,5-dihydrofurans, available by CAN-mediated reaction of styrenes with benzoylacetones, afforded functionalized 9,10-dihydrophenanthrenes. These reactions proceed by a novel domino [3+3] cyclization/ring-opening/Friedel-Crafts alkylation process.