958463-35-9

Upstream product

• 54974-07-1 phthalimidesulfenyl chloride 
• 958463-36-0 2,3-dimethyl-4-[[(1,1-dimethylethyl)dimethylsilyl]oxy]phenol 

Downstream Products

• 958463-40-6 C₂₃H₃₂O₃SSi 
• 958463-41-7 C₃₄H₅₈O₄SSi₃ 
• 1448175-44-7 4-(tert-butyldimethylsilyloxy)-2,3-dimethyl-6-(1H-pyrrol-2-ylthio)phenol 
• 1448175-37-8 4-(tert-butyldimethylsilyloxy)-6-(1H-indol-3-ylthio)-2,3-dimethylphenol 

Relevant academic research and scientific papers

A straightforward hetero-diels-alder approach to (2-ambo,4′R, 8′R)-α/β/γ/δ-4-thiatocopherol

A simple and original inverse electron demand hetero-Diels-Alder reaction has been successfully applied to the synthesis of (2-ambo,4′R,8′R)- α/β/γ/δ-4-thiatocopherol. Commercially available methyl hydroquinones and. (2E,7R,11R)-(+)-phytol were exploited for the preparation of the ortho-thioquinones, acting as electron-poor dienes, and of the proper 1,3-diene used as dienophile, respectively. The benzoxathiine cycloadducts, with the required tocopherol-like skeleton, were obtained with complete control, of regio and chemoselectivity. The antioxidant activity of 4-thiatocopherols was measured and rationalized in comparison with that of the corresponding natural components of Vitamin E.

Kinetic and thermochemical study of the antioxidant activity of sulfur-containing analogues of vitamin E

Sulfur-containing analogues of vitamin E (thiachromanols), either linked or not to a catechol moiety, were synthesized and their hydrogenatom donating ability evaluated. The determination of the O-H bond dissociation enthalpy (BDE) of the a-tocopherol analogue 4 by the electron paramagnetic resonance (EPR) equilibration technique provided a value of 78.9 kcal mol-1, that is, approximately 1.8 kcal mol-1 higher than that of α-to-copherol. The kinetic rate constants for the reaction with peroxyl radicals (kinh), measured by inhibited autoxidation studies, showed that thiachromanols react 2.5 times slower than the corresponding tocopherols, in agreement with the higher BDE value. This behavior was explained, on the basis of crystallographic analyses and DFT calculations, in terms of a change in the molecular geometry caused by insertion of a sulfur atom into the frame-work of vitamin E. This behavior implies a greater deviation of the condensed ring from coplanarity with the aromatic ring, thus giving rise to a decrease in the conjugative stabilization of the phenoxyl radical and consequently to an increase in the O-H bond strength. Although less reactive than tocopherols, thiachromanols may, however, act as bimodal antioxidants as a result of the hydroperoxide decomposing ability of the sulfur atom.