CuI-Mediated Synthesis of Sulfonyl Benzofuran-3-ones and Chroman-4-ones.

A concise, one-pot synthesis of sulfonyl benzofuran-3-ones and chroman-4-ones from α-sulfonyl o-hydroxyacetophenones is described, using a combination of K2CO3, CuI, and dimethylsulfoxide (DMSO). This annulation protocol generates one carbon-oxygen (C-O) bond and one carbon-carbon (C-C) bond in a highly efficient manner.