(...)-Fluoromethyl phenyl sulfoxide, a,a-difluoromethyl phenyl sulfoxide, a-bromo-a,a-difluoro sulfoxide, a-fluoromethyl phenyl sulfone and a,a-difluoro methyl phenyl sulfone were synthesized. These compounds are useful in organic synthesis. Preliminary investigation on the possible existence of the a-fluoromethyl phenyl sulfoxide dianion and its reactions were studied. The reaction of a-lithio a-fluoromethyl phenyl sulfinyl carbanions with dihaloalkanes gave the cyclic fluorosulfoxides (Eq. 1). The reaction of such carbanions with 2-cyclohexenone and 2-cyclopentenone gave the corresponding 1,2-adducts and a small amount of 1,4-adducts in the presence of Lewis acid (Eq. 2). The reaction of a-lithio a-fluoromethyl with aldehydes gave corresponding a. fluoromethyl-,B-hydroxy phenyl sulfoxide in good yields. With a proper choice of reaction condition, flash vacuum pyrolysis of these conpounds gave the a-fluoro ketones in moderate yields. Flash vacuum pyrolysis of O-allylated-a-fluoro-,B-hydroxy phenyl sulfoxide, Claisen rearrangement, gave a-fluoro ketones in high yields(Scheme 1). Reactions of a-fluoromethyl phenyl sulfones with a,B-unsaturated carbonyl compounds depended on the type of carbonyl compounds. The results were obtained as follow: a. 2-Cyclohexenone, 2-cyclopentenone, also methyl acrylate, methyl crotonate, dimethyl alkylidene malonate yielded 1,4-adducts and a small amount of double Michael products. However methyl vinyl ketone gave 1,2-addition products and small amout of 1,4-adducts when activated with Lewis acids (Eq. 3). b. a,B-Unsaturated aldehydes gave 1,2-addition products exclusively (Eq. 4). Os o HO The reactions of a-fluoromethyl phenyl sulfones with imines and could the reaction be stopped at the acyclic adducts. Only acyclic adducts of aromatic imines could be alkylated at a-carbon bearing fluorine and sulfinyl groups (Eq. 5).