Stereoselective synthesis of α-disubstituted cyclopentanones by palladium-catalyzed rearrangement of allenylcyclobutanols with aryl halides

When allenylcyclobutanols having a 1-substituted allenyl group were treated with aryl iodides in the presence of palladium(0), ring-expanded cyclopentanones possesing quaternary carbon stereocenter at the α-position were stereoselectively obtained. The reactions can be applied to various kinds of allenylcyclobutanols and aryl halides.