Tin tetrachloride pentahydrate-catalyzed regioselective chlorohydroxylation of α,β-unsaturated ketones in water with Selectfluor as a chlorine source

A facile entry to α-chloro-β-hydroxy ketone derivatives via SnCl4·5H2O-catalyzed regioselective chlorohydroxylation of α,β-unsaturated carbonyl compounds is described. This reaction proceeded in water and is a rare example of Selectfluor serving as a chlorine source. The utility of the products was highlighted by the transformations to β-dicarbonyl compound and highly substituted 1,4-dioxane derivative. Some mechanistic investigations were also carried out, which suggested that a radical pathway was more likely to be involved.