Vinyl sulfones shift

Three possible mechanisms may be envisioned for this reaction. The first two i.e. 1) Michael addition of R M to the acetylenic sulfone followed by a-elimination of LiOjSPh to yield a vinyl carbene which undergoes a 1,2 aryl shift and 2) carbometallation of the acetylenic sulfone by R M followed by a straightforward -elimination, where discarded by the authors. The third mechanism in which the organometallic reagent acts as an electron donor and the central intermediates is the radical anion ... 

Configurations of the isomeric sulfonates and carboxylates of (134) have been derived from H and C NMR spectra <85CCC348>. The chemical shifts of the vinyl protons and their coupling constants in the H NMR spectra have enabled determination of the ( )- and (Z)-configurations, confirmed by the value of C shifts of C-1 and C-5. Analysis of the values of Vh,h[H-2,H-3 ... 

Sulfonyl-2-pyrones. Based on the NMR chemical shift data in Table 1, 3-arylsulfonyl-2-pyrones were expected to cycloadd to electron-rich dienophiles, such as vinyl ethers. Pyrone sulfone 47 underwent cycloaddition to ethyl vinyl ether at room temperature and ambient pressure in the absence of Lewis acid to give cycloadduct 48 in excellent yield. For steric and electronic reasons, it was expected... 

Svoboda et al. [160] investigated the emulsion copolymerization and ter-polymerization of VC with vinyl accetate, butyl acrylate and/or ethyl acrylate. The polymerizations proceeded under batch and continuous conditions and were initiated by peroxodisulfates. Anionic emulsifiers (sodium dodecyl sulfate, sodium dodecylbenzene sulfonate,..) and blends of anionic and non-ionic emulsifiers (mostly polyoxyethylene type) were used. Copolymer latexes prepared with emulsifier blends were much more stable than those with an anionic emulsifier. As expected, the copolymers prepared by continuous polymerization gave copolymers with homogeneous composition. In the batch copolymerizations, the shift in the copolymer composition with conversion was observed and particles with broader size distribution were prepared. For example, the batch VC/ethyl acrylate polymer latexes gave particles with a diameter from 180 nra to 320 nm. 

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