Highly Regioselective Gold-Catalyzed Ring-Opening Allylation and Azidation of Dihydrofurans

The ring-opening allylation and azidation of 2,5-dihydrofurans has been accomplished with allyltrimethylsilane or Me3SiN3 in the presence of catalytic amounts of HAuCl4 center dot 3H(2)O, Whereas the allylation proceeds regioselectively in the 2-position to afford 2,6-dien-1-ols, the azidation takes place in the 4-position exclusively.