A novel 1,5-rearrangement of a sulfonyl group in a 1-sulfenylated 2,4-alkadiene
1-Substituted 1-methylthio-2,4-pentadien-1-yl sulfones (4) smoothly underwent a 1,5-rearrangement of a sulfonyl group by the action of silica gel. Its application to a new synthesis of conjugated dienones is also described.