When sulfoxides are reacted with alkyllithiums two competing reactions can occur: (i) abstraction of an α-hydrogen to give an α-lithiosulfoxide and (ii) carbon–sulfur bond cleavage according to R1S(O)R2 + R3Li → R1S(O)R3 + R2Li. In the cleavage reaction the group which can best carry a negative charge is most readily displaced. The displacements occur with inversion of configuration at sulfur. t-Butyllithium racemizes optically active t-butyl aryl sulfoxides within a few minutes at −78° in tetrahydrofuran. The results show that in general t-butyl-lithium and n-butyllithium are unsatisfactory bases for the efficient generation of α-lithio sulfoxides. Methyllithium or lithium diisopropyl amide are better suited for this purpose.