The synthesis and reactivity of propargylic and allylic trifluoromethanesulfinates under various conditions has been investigated. Propargylic esters readily undergo (2,3)-sigmatropic rearrangement to the corresponding allenyl trifluoromethyl sulfones, even under solvolytic conditions. An unusually facilenucleophilic addition of the solvent to the allenyl sulfone under the latter conditions has also