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- Ramberg–Bäcklund_reaction abstract "The Ramberg–Bäcklund reaction is an organic reaction converting an α-halo sulfone into an alkene in presence of a base with extrusion of sulfur dioxide. The reaction is named after the two Swedish chemists Ludwig Ramberg and Birger Bäcklund. The carbanion formed by deprotonation gives an unstable thiirane dioxide that decomposes with elimination of sulfur dioxide. This elimination step is considered to be a concerted cycloelimination.The overall transformation is the conversion of the carbon–sulfur bonds to a carbon–carbon double bond. The original procedure involved halogenation of a sulfide, followed by oxidation to the sulfone. Recently, the preferred method has reversed the order of the steps. After the oxidation, which is normally done with a peroxy acid, halogenation is done under basic conditions by use of dibromodifluoromethane for the halogen transfer step. This method was used to synthesize 1,8-diphenyl-1,3,5,7-octatraene.The Ramberg–Bäcklund reaction has several applications. Due to the nature of elimination, it can be applied to both small rings ,and large rings containing a double bond .The necessary α-halo sulfones are accessible through oxidation of the corresponding α-halo sulfides with peracids such as meta-chloroperbenzoic acid; oxidation of sulfides takes place selectively in the presence of alkenes and alcohols. α-Halo sulfides may in turn be synthesized through the treatment of sulfides with halogen electrophiles such as N-Chlorosuccinimide or N-Bromosuccinimide.The sulfone group contains an acidic proton in one of the α-positions which is abstracted by a strong base (scheme 1). The negative charge placed on this position (formally a carbanion) is transferred to the halogen residing on the other α-position in a nucleophilic displacement temporarily forming a three-membered cyclic sulfone. This intermediate is unstable and releases sulfur dioxide to form the alkene. Mixtures of cis isomer and trans isomer are usually obtained.This reaction type gives access to 1,2-dimethylenecyclohexaneand the epoxide variation access to allyl alcohols.The Favorskii rearrangement and the Eschenmoser sulfide contraction are conceptually related reactions.A recently developed application of the Ramberg–Bäcklund reaction is the synthesis of C-glycosides. The required thioethers can be prepared easily by exchange with a thiol. The application of the Ramberg–Bäcklund conditions then leads to an exocyclic vinyl ether that can be reduced to the C-nucleoside .".
- Ramberg–Bäcklund_reaction thumbnail RambergBacklundreaction.png?width=300.
- Ramberg–Bäcklund_reaction wikiPageExternalLink prep.asp?prep=cv8p0212.
- Ramberg–Bäcklund_reaction wikiPageID "4735673".
- Ramberg–Bäcklund_reaction wikiPageLength "7966".
- Ramberg–Bäcklund_reaction wikiPageOutDegree "46".
- Ramberg–Bäcklund_reaction wikiPageRevisionID "679402580".
- Ramberg–Bäcklund_reaction wikiPageWikiLink Alkene.
- Ramberg–Bäcklund_reaction wikiPageWikiLink Allyl_alcohol.
- Ramberg–Bäcklund_reaction wikiPageWikiLink Base_(chemistry).
- Ramberg–Bäcklund_reaction wikiPageWikiLink Canadian_Journal_of_Chemistry.
- Ramberg–Bäcklund_reaction wikiPageWikiLink Carbanion.
- Ramberg–Bäcklund_reaction wikiPageWikiLink Category:Carbon-carbon_bond_forming_reactions.
- Ramberg–Bäcklund_reaction wikiPageWikiLink Category:Elimination_reactions.
- Ramberg–Bäcklund_reaction wikiPageWikiLink Category:Name_reactions.
- Ramberg–Bäcklund_reaction wikiPageWikiLink Chemical_Communications.
- Ramberg–Bäcklund_reaction wikiPageWikiLink Cis–trans_isomerism.
- Ramberg–Bäcklund_reaction wikiPageWikiLink Dibromodifluoromethane.
- Ramberg–Bäcklund_reaction wikiPageWikiLink Epoxide.
- Ramberg–Bäcklund_reaction wikiPageWikiLink Eschenmoser_sulfide_contraction.
- Ramberg–Bäcklund_reaction wikiPageWikiLink European_Journal_of_Organic_Chemistry.
- Ramberg–Bäcklund_reaction wikiPageWikiLink Favorskii_rearrangement.
- Ramberg–Bäcklund_reaction wikiPageWikiLink Halogen.
- Ramberg–Bäcklund_reaction wikiPageWikiLink Hydrogen.
- Ramberg–Bäcklund_reaction wikiPageWikiLink Journal_of_the_American_Chemical_Society.
- Ramberg–Bäcklund_reaction wikiPageWikiLink Liebigs_Annalen.
- Ramberg–Bäcklund_reaction wikiPageWikiLink Ludwig_Ramberg.
- Ramberg–Bäcklund_reaction wikiPageWikiLink Meta-Chloroperoxybenzoic_acid.
- Ramberg–Bäcklund_reaction wikiPageWikiLink N-Bromosuccinimide.
- Ramberg–Bäcklund_reaction wikiPageWikiLink Nucleophilic_substitution.
- Ramberg–Bäcklund_reaction wikiPageWikiLink Organic_Reactions.
- Ramberg–Bäcklund_reaction wikiPageWikiLink Organic_Syntheses.
- Ramberg–Bäcklund_reaction wikiPageWikiLink Organic_reaction.
- Ramberg–Bäcklund_reaction wikiPageWikiLink Peroxy_acid.
- Ramberg–Bäcklund_reaction wikiPageWikiLink Redox.
- Ramberg–Bäcklund_reaction wikiPageWikiLink Sulfide.
- Ramberg–Bäcklund_reaction wikiPageWikiLink Sulfone.
- Ramberg–Bäcklund_reaction wikiPageWikiLink Sulfur_dioxide.
- Ramberg–Bäcklund_reaction wikiPageWikiLink Tetrahedron_(journal).
- Ramberg–Bäcklund_reaction wikiPageWikiLink Thiol.
- Ramberg–Bäcklund_reaction wikiPageWikiLink File:EpoxideRBreaction.png.
- Ramberg–Bäcklund_reaction wikiPageWikiLink File:Ramberg-Backlund_Reaction_synthesis_of_1,8-diphenyl-1,3,5,7-octatetraene.png.
- Ramberg–Bäcklund_reaction wikiPageWikiLink File:Ramberg-Backlund_Reaction_to_synthesize_C-Nucleoside_Formation.png.
- Ramberg–Bäcklund_reaction wikiPageWikiLink File:Ramberg-Backlund_Ring_Application_1.png.
- Ramberg–Bäcklund_reaction wikiPageWikiLink File:Ramberg-Backlund_Ring_Application_2.png.
- Ramberg–Bäcklund_reaction wikiPageWikiLink File:RambergBacklundDimethylenecyclohexane.png.
- Ramberg–Bäcklund_reaction wikiPageWikiLink File:RambergBacklundreaction.png.
- Ramberg–Bäcklund_reaction wikiPageWikiLinkText "Ramberg-Backlung ring contraction".
- Ramberg–Bäcklund_reaction wikiPageWikiLinkText "Ramberg–Bäcklund reaction".
- Ramberg–Bäcklund_reaction wikiPageUsesTemplate Template:Cite_book.
- Ramberg–Bäcklund_reaction wikiPageUsesTemplate Template:Cite_journal.
- Ramberg–Bäcklund_reaction wikiPageUsesTemplate Template:Note.
- Ramberg–Bäcklund_reaction wikiPageUsesTemplate Template:Ref.
- Ramberg–Bäcklund_reaction wikiPageUsesTemplate Template:Use_dmy_dates.
- Ramberg–Bäcklund_reaction subject Category:Carbon-carbon_bond_forming_reactions.
- Ramberg–Bäcklund_reaction subject Category:Elimination_reactions.
- Ramberg–Bäcklund_reaction subject Category:Name_reactions.
- Ramberg–Bäcklund_reaction hypernym Reaction.
- Ramberg–Bäcklund_reaction type Disease.
- Ramberg–Bäcklund_reaction type Diacritic.
- Ramberg–Bäcklund_reaction type Eponym.
- Ramberg–Bäcklund_reaction type Reaction.
- Ramberg–Bäcklund_reaction type Redirect.
- Ramberg–Bäcklund_reaction comment "The Ramberg–Bäcklund reaction is an organic reaction converting an α-halo sulfone into an alkene in presence of a base with extrusion of sulfur dioxide. The reaction is named after the two Swedish chemists Ludwig Ramberg and Birger Bäcklund. The carbanion formed by deprotonation gives an unstable thiirane dioxide that decomposes with elimination of sulfur dioxide.".
- Ramberg–Bäcklund_reaction label "Ramberg–Bäcklund reaction".
- Ramberg–Bäcklund_reaction sameAs Q1935557.
- Ramberg–Bäcklund_reaction sameAs Reacció_de_Ramberg-Bäcklund.
- Ramberg–Bäcklund_reaction sameAs Ramberg-Bäcklund-Reaktion.
- Ramberg–Bäcklund_reaction sameAs Reacción_de_Ramberg-Backlund.
- Ramberg–Bäcklund_reaction sameAs ランバーグ・バックランド反応.
- Ramberg–Bäcklund_reaction sameAs Ramberg-Bäcklund-reactie.
- Ramberg–Bäcklund_reaction sameAs Reação_de_Ramberg-Bäcklund.
- Ramberg–Bäcklund_reaction sameAs m.0ckmhq.
- Ramberg–Bäcklund_reaction sameAs Q1935557.
- Ramberg–Bäcklund_reaction sameAs 兰堡–巴克伦反应.
- Ramberg–Bäcklund_reaction wasDerivedFrom Ramberg–Bäcklund_reaction?oldid=679402580.
- Ramberg–Bäcklund_reaction depiction RambergBacklundreaction.png.
- Ramberg–Bäcklund_reaction isPrimaryTopicOf Ramberg–Bäcklund_reaction.