Chiral Hypervalent Iodine(III) Catalyst Promotes Highly Enantioselective Sulfonyl- and Phosphoryl-oxylactonizations.

An efficient enantioselective hypervalent iodine promoted oxylactonization of 4-pentenoic acids has been achieved using stoichiometric or a catalytic amount of chiral aryl-λ3-iodane. This reaction provides straightforward access to a wide range of sulfonyloxy- and phosphoryloxy-γ-butyrolactones in respectable yields with moderate to excellent enantioselectivities.