Piotr Lyzwa

A NEW PROCEDURE FOR OXIDATION OF SULFIDES TO SULFONES

Abstract A series of variously substituted sulfones has been synthesized by oxidation of the corresponding sulfides with the hydrogen peroxide/selenium dioxide system. Very short reaction time, easy work-up and high yields make this new preparation of sulfones a recommendable method.

A NEW ASYMMETRIC SYNTHESIS OF CHIRAL t-BUTYL t-BUTANETHIOSULPHINATE1

Abstract Thermal decomposition of di-t-butyl sulphoxide (3) in the presence of chiral amines has been found to give chiral t-butyl t-butanethiosulphinate (1). Optical purities of 1 were in the range between 1 and 26%.

New Oxidation Procedures Based on the use of Selenium Derivatives as Reagents and Catalysts

New procedures for the oxidation of selected groups of organic compounds based on the use of selenium derivatives as reagents and catalysts are described.

Asymmetric Syntheses of α-Sulfinylphosphonates in the Thiolane Series

Enantiopure α-sulfinyl phosphonates are useful chiral olefinating reagents for the generation of α,β-ethylenic sulfoxides, which in turn can be used as asymmetric dienophiles or Michael acceptors.1 The first enantioselective synthesis of a 1-oxo 2-phosphonothiolane 2 had already been achieved via the [2,3]-sigmatropic rearrangement of the carbanion derived from di(-)-menthyl (allylsulfanyl)methanephosphonate.2 We now describe more direct and general ways to prepare nonracemic sulfoxides of the same series by the methods involving asymmetric oxidations of racemic or achiral thiolanes. When racemic 2-phosphonothiolanes 1 (R = ethyl, isopropyl, 2,2-dimethylpropane-1,3-diyl), prepared from 1-oxothiolane by a Pummerer-phosphorylation reaction,3 were treated with one half equiv of (+)-(2S, 8aR)-8,8-dichloro-camphorsulfonyloxaziridine, a preferential oxidation of one of the enantiomers of thiolane 1, together with a diastereoselective formation of the trans-sulfoxides 2, was observed leading to enantioenriched 1 and 2 (ee ∼ 75% with R = iPr) 2-Phosphono-2,3-didehydrothiolanes 3 were further prepared from the racemic sulfoxides 2 under Pummerer conditions. Their enantioselective oxidation using the same oxaziridine led to the enantioenriched