Microwave-assisted dehydration-oxidation of 𝛽-bromo-tert-alcohols to afford 2,3-unsaturated ketones in good yield is reported. The reaction of substrates with DMSO in 1:1 ratio (w/v) is promoted by ZnS in a solvent-free condition. A concurrent bi-functional activation of trans-vicinal bromo- and hydroxyl groups with ZnS is elucidated. This is a new observation under microwave and applies to 𝛽-bromo-tert-alcohols derived from 1,4-disubstitued-1-cyclohexenes. It is very useful in the synthesis of 2,3-unsaturated ketones derived from monoterpenes which are valuable flavour compounds.
