The preparation of the title compounds as a new type of stable S-ylides has been described. The reaction of 1-dimethylsulfuranylidene-1-phenylsulfonyl-2-propanone (IIb) with lithium aluminium hydride was found to result in the formation of trans-phenylpropenylsulfone (IV), phenylsulfonyl-2-propanone (Ib), and an unidentified paraffin as major products.