Hydroxy thioethers formation

The latter reaction sequence was of importance since addition of the thiol glutathione to arene-oxide intermediates under control of hepatic glutathione-S-epoxide transferase enzyme(s) is a very important metabolic transformation. It would appear probable that most of the structures of the arene oxide-glutathione adducts (premercapturic acids) reported in the literature before 1975 are incorrect with respect to the position of the hydroxy and thioether substituents (they should now be reversed). Addition of thiomethoxide anion to arene oxide 70 may occur via 1,6- and 1,4-addition, although one of these thioether adducts could also be accounted for by the alternative arene-oxide intermediate obtained from an oxygen-walk. Styrene 3,4-oxide (S3) has been observed to react with ethanethiol to yield three adducts which appear to aromatize to three isomeric ethylthiostyrenes without the formation of episulphonium intermediates. ... 

The halogen functional polymer can react with a thiol by nucleophilic reaction, resulting in a polymeric thioether and a hydrogen halide. The latter is trapped by a basic additive, preventing a reverse reaction. Snijder et al. [135] used this technique to modify the end group of poly( -butyl acrylate) into a hydroxy-functional polymer. With 2-mercaptoethanol, the yield of functionalization was higher with the addition of 1,4-diazabicyclo[2,2,2]octane (DABCO) to the reaction mixture. The addition of DABCO allows for the formation of a sulfide anion, which is a stronger nucleophile. They studied this... 

Notable new general syntheses of butenolides include the addition of the three-carbon synthon Li(PhS)C=CMeC02Me to aldehydes R CHO (R = alkyl or aryl) to yield the thioethers (19), the related reaction of lithio-j8-lithio-acrylates R CLi=CR C02Li with benzaldehyde to give compounds (20 R = H or Me), and the formation of (21) from the iodinated allyl alcohol ICMe=CHCH20H and carbon monoxide in the presence of bis(triphenylphos-phine)palladium(ii) chloride. Chloral reacts with dimethyl (benzylamino)fu-marate to yield the butenolide (22), whereas aromatic aldehydes give hydroxy-pyrrolinones (23). The total synthesis of piperolide (24) has been reported. 

In view of the relative ease of stereocontrolled formation of the 26-di-alkylaminoalkylthio derivatives obtained from pristinamycin 11 which were active in vivo in association with pristinamycin I, the chemistry of these compounds was explored further. Their in vivo activity in association with pristinamycin 1 might be explained by oxidative metabolism of these thioethers in the animal model to the corresponding sulfoxides and/or sulfones. Due to the presence of different oxidizable functionalities including the hydroxy group (see Sect. 5.4.1), the conjugated double bonds (see Sect. 5.4.4), the amino function of... 

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