- "Syn-Effect" in the Conversion of (E)-Vinylic Sulfones to the Corresponding Allylic Sulfones
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It was found that (E)-vinylic sulfones preferentially afford (Z)-allylic sulfones as kinetically-controlled products by treatment with a base under mild conditions, while (Z)-vinylic sulfones give (E)-allylic sulfones.Such stereochemical relationship was
- Hirata, Takaki,Sasada, Yoshihiro,Ohtani, Takashi,Asada, Takahiro,Kinoshita, Hideki,et al.
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- A 1,3-Rearrangement of Allylic Sulphones Caused by m-Chloroperbenzoic Acid and Sodium Hydrogen Carbonate
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The reaction of allylic sulphones with m-chloroperbenzoic acid in the presence of aqueous sodium hydrogen carbonate can result in 1,3-allylic rearrangement or isomerisation of the double bond depending on the structure of the allylic sulphone.Subsequent e
- Kocienski, Philip
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p. 945 - 948
(2007/10/02)
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- The Influence of Chain-branching on the Steric Outcome of Some Olefin-forming Reactions
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When applied to the construction of internal disubstituted double bonds in compounds such as pentadec-7-ene and 2,6,11,15-tetramethylhexadeca-2,6,8,10,14-pentaene (5), the reductive elimination of vicinal benzoyloxy-sulphones gives products with a trans:cis ratio of ca. 4:1.When applied to the construction of disubstituted olefins in which branching occurs adjacent to the newly formed double bond, much higher trans-stereoselectivity is observed, e.g. for 5-ethyl-2-methylhept-3-ene (21) and 3,6-dimethylocta-2,4,6-triene (25) it is at least 98percent.A similar effect of chain-branching is also observed in some Wittig and Horner reactions using primary allylic phosphorus derivatives.When a Z-allylic sulphone is used as the starting material in the benzoyloxy-sulphone method, the original Z-geometry is preserved in the product; (Z)-2-methylbut-2-enyl p-tolyl sulphone and tiglic aldehyde give almost exclusively (2E,4E,6Z)-3,6-dimethylocta-2,4,6-triene (27).
- Kocienski, Philip J.,Lythgoe, Basil,Waterhouse, Ian
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p. 1045 - 1050
(2007/10/02)
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