Claisen rearrangement
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Transcript of Claisen rearrangement
Applications of Claisen Rearrangement11311984Sineth hasun
What is Claisen rearrangement
The Claisen rearrangement is a powerful carbon–carbon bond-forming chemical reaction discovered by Rainer Ludwig Claisen. The heating of an allyl vinyl ether will initiate a [3,3]-sigmatropic rearrangement to give a γ,δ-unsaturated carbonyl.
Applications of Claisen Rearrangement
• Aromatic Claisen Rearrangement • Aliphatic Claisen Rearrangement• Thio-Claisen Rearrangement• Tandem Reaction • Aza-Claisen Rearrangement • Thio-Claisen Rearrangement • Retro-Claisen Rearrangement
Aromatic Claisen Rearrangement
The aromatic variation of the Claisen rearrangement is the [3,3]-sigmatropic rearrangement of an allyl phenyl ether to an intermediate which quickly tautomerizes to an ortho-substituted phenol
Aliphatic Claisen Rearrangement
The aliphatic Claisen (oxa-Cope), in contrast to the all-carbon Cope, has the advantage that the equilibrium constant is reliably favorable in the direction of the carbonyl compound. Claisen himself discovered the earliest example of sigmatropic rearrangement of an allyl enol ether: Claisen Chem. Ber. 1912, 42, 3157
several effective protocols to synthesize the required allyl enol ethers have been developed: the enol ether Claisen, the Johnson orthoester Claisen, and the Ireland silyl ketene acetal Claisen.
The Eschenmoser Amide Claisen Process
Eschenmoser Helv. Chim. Acta 1964,
Claisen Rearrangment of a Propargyl alcohol
Male Dried Bean Beetle Sex Pheromone. Kocienski, P.; Cernogliaro, G.; Feldstein, G. J. Org. Chem. 1977, 42, 353
File usage • www.commons.wikimedia.org/wiki/
File:Overman_Rearrangement
• www.chem.wisc.edu/areas
• www.organic-chemistry.org › Reactions › Name Reactions
• xlink.rsc.org › Journals › Organic & Biomolecular