A new synthesis of γ-butyrolactones via AuCl(3)- or Hg(II)-catalyzed intramolecular hydroalkoxylation of 4-bromo-3-yn-1-ols.

An efficient conversion of 4-bromo-3-yn-1-ols to γ-butyrolactones via AuCl(3)-catalyzed electrophilic cyclization (hydroxyl-assisted regioselective hydration) in wet toluene is described. Various secondary and tertiary alcohols including benzylic systems were found to be equally reactive with moderate to excellent yields obtained in all cases.