Synthesis of Vinyl Sulfones and Benzoxathiins via Base‐Catalyzed Reactions of o‐Hydroxyaryl Thiosulfonates and Ynones

The cyclization reaction and hydrosulfonylation reaction of ynones have been simultaneously realized through a single operation. Under the mediation of cesium carbonate, different S‐(α‐hydroxyaryl) aryl thiosulfonates reacted with various ynones to produce functionalized vinyl sulfones in 37%‐83% yields with E‐selectivity. At the same time, a variety of benzoxathiins were formed in 42%‐97% yields.