Synthesis of oxygen heterocycles by regioselective Heck reaction

The regioselective Heck arylation of unsaturated alcohols is utilized as the key step in a convenient one-pot procedure for the production of 2,2-disubstituted tetrahydrofurans and tetrahydropyrans. The arylation reaction is effected with a palladium-diphosphine catalyst alongside a hydrogen bond donor; this is followed by the introduction of a Br?nsted acid to the reaction mixture, affording the oxygen heterocycles in moderate yields.