Search results
Results from the WOW.Com Content Network
The Cope rearrangement is the prototypical example of a concerted sigmatropic rearrangement. It is classified as a [3,3]-sigmatropic rearrangement with the Woodward–Hoffmann symbol [π 2 s + σ 2 s + π 2 s] and is therefore thermally allowed.
The Cope rearrangement is an extensively studied organic reaction involving the [3,3] sigmatropic rearrangement of 1,5-dienes. [ 14 ] [ 15 ] [ 16 ] It was developed by Arthur C. Cope . For example, 3,4-dimethyl-1,5-hexadiene heated to 300 °C yields 2,6-octadiene.
The aza-Cope rearrangements are predicted by the Woodward-Hoffman rules to proceed suprafacially. However, while never explicitly studied, Overman and coworkers have hypothesized that, as with the base-catalyzed oxy-Cope rearrangement, the charged atom distorts the sigmatropic rearrangement from a purely concerted reaction mechanism (as expected in the Cope rearrangement), to one with partial ...
The reverse or retro-Cope elimination has been reported, in which an N,N-disubstituted hydroxylamine reacts with an alkene to form a tertiary N-oxide. [ 9 ] [ 10 ] The reaction is a form of hydroamination and can be extended to the use of unsubstituted hydroxylamine, in which case oximes are produced.
In organic chemistry, the oxy-Cope rearrangement is a chemical reaction.It involves reorganization of the skeleton of certain unsaturated alcohols. It is a variation of the Cope rearrangement in which 1,5-dien-3-ols are converted to unsaturated carbonyl compounds by a mechanism typical for such a [3,3]-sigmatropic rearrangement.
Main page; Contents; Current events; Random article; About Wikipedia; Contact us; Pages for logged out editors learn more
Arthur C. Cope (June 27, 1909 – June 4, 1966) was an American organic chemist and member of the United States National Academy of Sciences. He is credited with the development of several important chemical reactions which bear his name including the Cope elimination and the Cope rearrangement .
By contrast, in pericyclic reactions, the atoms under chemical change form a single closed cycle, and include reactions like the Diels–Alder reaction and Cope rearrangement, among many others. In contrast to these types of reactions, a coarctate reaction is characterized by a doubly cyclic transition state, in which at least one atom ...