Synthesis of conjugated diallenes by double [2,3]-sigmatropic rearrangement of conjugated diyne trichloromethanesulfenates

The preparation of several 2,4-diyne-1,6-diols and their esterification with trichloromethanesulfenyl chloride is described. The thus generated bis- propargylic trichloromethanesulfenates undergo spontaneous double [2,3]- sigmatropic rearrangement which leads to the formation of conjugated diallenic trichloromethyl sulfoxides in good to excellent yields.