Kondakov acylation
The Kondakov acylation , also Kondakoff acylation, is a name reaction in organic chemistry and was first published in 1892 by IL Kondakow . AG Darzens published extensions of the reaction in 1910, whereby the reaction is also known as Darzens olefin acylation . The reaction describes the synthesis of β-haloketones from alkenes and carboxylic acid halides .
Overview reaction
An alkene, e.g. B. 2,3-dimethyl-2-butene, reacts with a carboxylic acid halide (X usually Cl), under the influence of a Lewis acid , to form a β-haloketone:
Reaction mechanism
The reaction mechanism is described in the literature. The mechanism is illustrated here with a carboxylic acid chloride and aluminum chloride as the Lewis acid.
With the addition of aluminum chloride as Lewis acid, the carboxylic acid chloride 1 reacts to form an acyl ion. The aluminum chloride is converted into tetrachloroaluminate:
The reactive acyl ion reacts with an alkene - in the example 2,3-dimethyl-2-butene ( 2 ) - to form intermediate 3 . Intermediate 3 reacts to form β-chloroketone 4 with regression of the tetrachloroaluminate to aluminum chloride :
Individual evidence
- ↑ Herbert H. Seltzman, Yung Ao Hsieh, Colin G. Pitt and Patricia H. Reggio (1991): Synthesis of rotationally restricted tetrahydrocannabinol ethers In: J. Org. Chem. 56 (4), pp. 1549–1553, doi: 10.1021 / jo00004a039 .
- ↑ Kondakoff, J. (1893): About the syntheses under the influence of zinc chloride , Journal for practical chemistry , 48, pp. 467-486. doi: 10.1002 / prac.18930480148 .
- ^ Z. Wang: Comprehensive organic name reactions and reagents Volume 1 . John Wiley, Hoboken (NJ) 2009, ISBN 978-0-470-28662-3 , pp. 848-850 .