Asymmetric induction and diastereomeric ratio in the enzymatic oxygenation of various sulfides to the corresponding sulfoxides with hepatic mirosomal cytochrome P-450 obtained from phenobarbital pretreated rabbit were investigated in comparison with those of nonenzymatic oxidation with m-chloroperbenzoic acid and sodium metaperiodate. While substantial asymmetric inductions were observed in the sulfoxides formed by the enzymattc oxygenations, diastereomeric ratios of the sutfoxides formed were also quite different from those obtained by oxidation with m-chloroperbenzoic acid and sodium metaperiodate.

Sulfinyl sulfone was confirmed as a stable intermediate in direct NMR study on the oxidation of thiosulfonic S-ester with MCPBA in CDCL3, by comparing the chemical shifts with those of the authentic sample prepared by condensation method.

New one-pot syntheses of both unsymmetrical disulfides and thiolsulfonates by treatment of thionitrites with thiols and sulfinic acids are reported.

The Pummerer reaction, viz., the reaction of sulfoxides having at least one methyl or methylene group with carboxylic acid anhydride gives α-acyloxy derivatives of the corresponding sulfide. Earlier, we suggested on the basis of 18O tracer experiments with 18O-labeled acetic anhydride that the Pummerer reaction of dimethyl sulfoxide with acetic anhydride proceeds through an intermolecular nucleophilic attack of acetoxy group on the methylene carbon of the ylide-ylene intermediate. Noticeable acetoxy interchange has been found to take place during a similar Pummerer reaction of aryl methyl sulfoxide. However, the Pummerer reaction is the main path when the reaction with acetic anhydride is performed at around 120°C. In the Pummerer reaction of aryl methyl sulfoxides, the substituent effect is large (ρ=−1.6) and the kinetic isotope effect (kH/kD) is also substantial, i.e., 2.9. The reaction is assumed to involve the initial acetylation and the subsequent slow proton removal steps. Addition of sodium perchlorate or acetic acid accelerates the acetoxy exchange reaction rather than the Pummerer reaction.

Small electronic effects were discernible for rates of thermal racemization of various S-o-anisyl S-phenyl N-(substituted)sulfilimines. The rate was retarded by the electron-withdrawing group on the nitrogen atom. A correlation was found further between the rate and the streching frequency ( νS-N).