Carroll rearrangement
The Carroll rearrangement is a name reaction from the field of organic chemistry and was first observed in 1940 by Michael Francis Carroll . Part of the reaction mechanism involves the Cope rearrangement , which is why the Carroll rearrangement is also called the Kimel-Cope rearrangement.
Overview reaction
The Carroll rearrangement is carried out at 130 to 220 ° C.
There is a rearrangement of β-ketoesters to γ, δ-unsaturated ketones . The group marked in gray is released in the form of carbon dioxide . The radical R stands for alkyl groups .
Possible mechanism
The following mechanism of the Carroll rearrangement is explained using the example of allyl acetoacetate:
Allyl acetoacetate ( 1 ) enolizes and, after the Cope rearrangement, reacts to form intermediate 2 , which reacts further with elimination of carbon dioxide and is converted into ketone 3 by the keto-enol tautomerism .
application
The Caroll rearrangement is mainly used in the preparation and subsequent processing of γ, δ-unsaturated ketones. Due to the high temperatures, the process is not used in industry.
literature
- Bradford P. Mundy, Michael G. Ellerd, Frank G. Favaloro: Name Reactions and Reagents in Organic Synthesis. 2nd Edition. John Wiley & Sons, New York 2005, ISBN 0-471-22854-0 , pp. 134-135.
- Zerong Wang: Comprehensive Organic Name Reactions and Reagents. 1st edition. John Wiley & Sons, New Jersey 2009, ISBN 978-0-471-70450-8 , pp. 611-614.
- Martha Windholz: The Merck Index. 9th edition. MERCK & CO., Inc., New Jersey 1976, ISBN 0-911910-26-3 , p. 16.