enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Wagner–Meerwein rearrangement - Wikipedia

    en.wikipedia.org/wiki/Wagner–Meerwein...

    A Wagner–Meerwein rearrangement is a class of carbocation 1,2-rearrangement reactions in which a hydrogen, alkyl or aryl group migrates from one carbon to a neighboring carbon. [ 1 ] [ 2 ] They can be described as cationic [1,2]- sigmatropic rearrangements, proceeding suprafacially and with stereochemical retention.

  3. Ring expansion and contraction - Wikipedia

    en.wikipedia.org/wiki/Ring_expansion_and_contraction

    The cationic rearrangement contraction proceeds through the loss of a leaving group and the migration of an endocyclic bond to the carbocation. Pinacol type rearrangements are often used for this type of contraction. [20] Like the expansion reaction this proceeds with an electron donating group aiding in the migration.

  4. Rearrangement reaction - Wikipedia

    en.wikipedia.org/wiki/Rearrangement_reaction

    In organic chemistry, a rearrangement reaction is a broad class of organic reactions where the carbon skeleton of a molecule is rearranged to give a structural isomer of the original molecule. [1] Often a substituent moves from one atom to another atom in the same molecule, hence these reactions are usually intramolecular.

  5. Demjanov rearrangement - Wikipedia

    en.wikipedia.org/wiki/Demjanov_rearrangement

    This displacement can occur via a rearrangement (path A), in which one of the sigma bonds adjacent to the diazo group migrates. This migration results in an expansion of the ring. The resulting carbocation is then attacked by a molecule of water. Alternately, the diazo group can be displaced directly by a molecule of water in an S N 2 reaction ...

  6. 1,2-rearrangement - Wikipedia

    en.wikipedia.org/wiki/1,2-rearrangement

    The 1,2-rearrangement belongs to a broad class of chemical reactions called rearrangement reactions. A rearrangement involving a hydrogen atom is called a 1,2-hydride shift . If the substituent being rearranged is an alkyl group, it is named according to the alkyl group's anion : i.e. 1,2-methanide shift , 1,2-ethanide shift , etc.

  7. Oxymercuration reaction - Wikipedia

    en.wikipedia.org/wiki/Oxymercuration_reaction

    In practice, the mercury adduct product created by the oxymercuration reaction is almost always treated with sodium borohydride (NaBH 4) in aqueous base in a reaction called demercuration. In demercuration, the acetoxymercury group is replaced with a hydrogen in a stereochemically insensitive reaction [6] known as reductive elimination. The ...

  8. Koch reaction - Wikipedia

    en.wikipedia.org/wiki/Koch_reaction

    Carbocation rearrangements, etherization (in case an alcohol is used as a substrate, instead of an alkene), and occasionally substrate C N+1 carboxylic acids are observed due to fragmentation and dimerization of carbon monoxide-derived carbenium ions, especially since each step of the reaction is reversible. [15]

  9. Carbocation - Wikipedia

    en.wikipedia.org/wiki/Carbocation

    The IUPAC acknowledges the three divergent definitions of carbonium ion and urges care in the usage of this term. For the remainder of this article, the term carbonium ion will be used in this latter restricted sense, while non-classical carbocation will be used to refer to any carbocation with C–C and/or C–H σ-bonds delocalized by bridging.