72747-92-3

Upstream product

• 22452-23-9 trans-(4S,6R)-dimethyl-1,3-dithiane 
• 5954-76-7 threo-(2S,4R)-pentanedithiol 
• 24347-99-7 syn-pentane-2,4-diyl bis(4-methylbenzenesulfonate) 
• 1825-14-5 pentane-1,3-diol 

Relevant academic research and scientific papers

Development of a Robust Protocol for the Determination of Weak Acids' p KaValues in DMSO

Two methods for the determination of pKa values of weak acids are described, a direct titration with dimsyl potassium in the presence of an indicator and a back-titration in which an analyte/indicator mixture is deprotonated and then titrated with ammonium chloride. Both methods have been validated by measuring pKa values of compounds, for which values had been determined previously. The back-titration method was applied to measure pKa values of two 1,3-dithiane-derived bissulfoxides and a monosulfone.

Oxidation of Dithia Compounds: Comparative Experimental and Theoretical Studies on 1,3-Bis(methylthio)propane, Bis(methylthio)methane, and meso-4,6-Dimethyl-1,3-dithiane

1,3-Bis(methylthio)propane, bis(methylthio)methane, and meso-4,6-dimethyl-1,3-dithiane were oxidized with 1–4 equivalents of hydrogen peroxide, meta-chloroperbenzoic acid, sodium periodate, or potassium permanganate, respectively, and the amounts of oxidized substrates (sulfoxides and/or sulfones) were determined by NMR spectroscopy. Sulfanyl groups in the former starting material turned out to behave like independent functions, while a mutual influence of the sulfur functions was verified in the latter compounds. A meaningful investigation was possible in the conformationally constrained dithiane derivative. Oxidation of the dithiane with stoichiometric amounts of periodate led to exclusive formation of bissulfoxides, while hydrogen peroxide and meta-chloroperbenzoic acid yielded the possible products less specifically and permanganate preferentially furnished sulfones. The experimental investigations were supported by calculations on energies and stereoelectronic effects of starting materials, products, and transition states. The unique property of permanganate to exclusively yield sulfones might be due to its special oxidation mechanism, where the sulfur is not only acting as nucleophile, but concomitantly as electrophilic moiety.

Conformationally constrained oxides of 1,3-dithiane: Synthesis and NMR spectroscopic investigations

Conformationally constrained derivatives of 1,3-dithianes (5-tert-butyl- and 4,6-dimethyl-1,3-dithiane and dithiadecalin) have been oxidised with various oxidants to yield axial and equatorial sulfoxides, disulfoxides and sulfones. Axial sulfoxides were prepared by nucleophilic hydroxide addition to the corresponding 2-alkylidene derivatives with subsequent retro-aldol-type elimination. The reaction outcome is related to the relative energies of the derivatives, as demontstrated by DFT calculations. The NMR spectroscopic data of the compounds obtained were analysed to identify 4J couplings. It was found that only 4J W couplings can be observed regardless of whether there is an axial or an equatorial sulfoxide, sulfide or sulfone group present in between the respective C-H moieties. A previously postulated γ-gauche effect of axial sulfoxides (but not of equatorial sulfoxides or sulfones) leading to the shielding of carbon atoms is not unambiguously supported by the NMR spectroscopic data of conformationally fixed derivatives. Copyright

The Reactions of O2 (1Δg) with Anancomeric 1,3-Dithianes. The First Experimental Evidence in Support of a Hydroperoxy Sulfonium Ylide as a Precursor to Sulfoxide on the Sulfide Singlet Oxygen Reaction Surface

The kinetic isotope effects for the formation of anancomeric 1,3-dithiane-1-oxides in the reactions of singlet oxygen with the parent 1,3-dithianes have been determined for a series of 2-protio and 2-deuterio analogues. The substantial isotope effects are used to argue for formation of a hydroperoxysulfonium ylide as a key intermediate in sulfoxide formation. These results confirm an earlier theoretical prediction and force a change in the currently accepted mechanism for this important reaction. The first experimental demonstration of a novel singlet oxygen-induced epimerization of a 1,3-dithiane and a novel intramolecular electron transfer within a hydroperoxysulfonium ylide are also reported.