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Jonczyk, A.; Kowalkowska, A., Science of Synthesis, (2006) 8, 1052.
The reaction of α-halo sulfones possessing α′-hydrogen(s) with a base, often sodium hydroxide, to give alkenes (via thiirane dioxides which extrude sulfur dioxide) is named the Ramberg–Bäcklund reaction.[579–583] When this process is applied to chloromethyl cyclohexyl sulfone, it affords methylenecyclohexane in 80% yield.[584] When the starting sulfones contain more halogens, the reaction often gives mixtures containing haloalkenes, alkynes, and α,β-unsaturated sulfonic acids.[585–588] The Ramberg–Bäcklund reaction may be carried out under phase-transfer catalysis conditions, in the presence of dilute sodium hydroxide, affording alkenes 83 in 75–94% yield (Scheme 62).[183,589] Sulfones substituted with the trifluoromethyl group potentially appear to be very useful substrates, and they require equimolar amounts of tetrabutylammonium hydrogen sulfate for successful Ramberg–Bäcklund reaction.[589] Among other synthetic applications, this approach is used in the preparation of the Artemisia ketone from a trifluoromethyl-substituted oxo sulfone.[589] A one-pot phase-transfer-catalyzed reaction of dibenzyl sulfone with carbon tetrachloride leads directly to (E)-stilbene in yields of 94–100%.[177,183]
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References
[177] | Meeeeeeee, M. M.; Møeeeee, M.; Meeeeeeøe, M., Meee Meee. Meeee., Mee. M, (8888) 88, 888. |
[183] | Meeeeee, M. M.; Meeeeee, M. M., Meeeeeeee, (8888), 888. |
[579] | Meeeeeee, M. M., Mee. Meee. Mee., (8888) 8, 888. |
[580] | Meeeeeee, M. M., Mee. Meeee. (M. M.), (8888) 88, 8. |
[581] | Meeeee, M. M., Me Meeeeeeeeeeee Meeeeee Meeeeeeee, Meeee, M. M.; Meeeeee, M., Mee.; Meeeeeee: Meeeee, (8888); Mee. 8, e 888. |
[582] | Meeeee, M. M. M., Meee. Meeeee. (Meeeeeeee), (8888), 888. |
[583] | Meeeeeee, M. M., Meeeeee, (8888), 8. |
[584] | Meeeeeee, M. M., M. Me. Meee. Mee., (8888) 88, 8888. |
[585] | Meeeeeee, M. M., M. Me. Meee. Mee., (8888) 88, 8888. |
[586] | Meeeeeee, M. M.; Meeeeeeeeee, M. M., M. Me. Meee. Mee., (8888) 88, 8888. |
[587] | Meeeeeee, M. M.; Meeeeeeeeee, M. M.; Meee, M. M., M. Me. Meee. Mee., (8888) 88, 8888. |
[588] | Meeeeeee, M. M.; Meeeeeeeeee, M. M., M. Me. Meee. Mee., (8888) 88, 8888. |
[589] | Meeeeeeeeee, M. M.; Meeeeeeee, M. M.; Meeeeee, M. M., M. Me. Meee. Mee., (8888) 888, 8888. |
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- 8.Meeeee-Meee, (8888) M 88-8, 8888.
- 8.Meeeee-Meee, (8888) M 88-8, 8888.
- 8.Meeeee-Meee, (8888) M 88-8, 8888.