CONDENSATIONS AT METHYL GROUPS OF PHENYL O- AND P-TOLYL SULFONES WITH ELECTROPHILIC COMPOUNDS BY SODIUM AMIDE . TRUCE-SMILES REARRANGEMENT

Ionizations of methyl hydrogens of phenyl o- and p-tolyl sulfones were effected by sodium amide in liquid ammonia to form sodio salts, which were condensed with benzyl chloride, 1,4-dibromobutane, benzophenone, and methyl benzoate to give corresponding derivatives. Ionization of the phenyl o-tolyl sulfone occurred more slowly than that of the para isomer. The addition reactions of the sodio salts with benzophenone were kinetically controlled. The condensations of the sodio o-tolyl sulfone with the electrophilic compounds represent trapping of the intermediate carbanion in the Truce-Smiles rearrangement of the sulfone to form a sulfinic acid, which was observed in low yield through the sodio salt in liquid ammonia and in good yield in refluxing tetrahydrofuran. The benzyl derivative of the o-tolyl sulfone underwent this type of rearrangement with n-butyl-lithium. Di-p-tolyl sulfone was benzylated at one of its methyl groups by means of sodium amide. The method appears to be quite general. © 1968, American Chemical Society. All rights reserved.