Gold-Catalyzed Synthesis of Oxetan-3-ones from Propargylic Alcohols

Significance

The gold-catalyzed synthesis of ­oxetan-3-ones 3 from propargylic alcohols 1 is reported. A range of substituents (R^¹) are tolerated, including acid labile (OMOM, NHBoc) and reactive (N₃, Br) groups. Tertiary propargylic alcohols 4 are also suitable substrates, although the electron-withdrawing ester is required to prevent the formation of undesired propargylic cations under the acidic reaction conditions. This methodology may also be used to prepare the volatile and expensive oxetan-3-one 7, which may be converted, without purification, into useful oxetane derivatives 8 and 9.