Hunsdiecker condensation
The Hunsdiecker condensation , named after the German chemist Heinz Hunsdiecker , is a name reaction from the field of organic chemistry and was first described in 1942. The Hunsdiecker condensation enables the synthesis of cyclopentenones by means of intra-molecular condensation of γ-diketones .
Overview reaction
In a basic environment, the elimination of water leads to a cyclopentenone ring closure of the γ-diketone (also called 1,4-diketone). The newly made bond is marked in blue :
Reaction mechanism
A 1,4-diketone 1 is deprotonated in a basic medium , whereby a carbanion 2 is formed. Electron rearrangement enables a ring closure to compound 3 . With water, compound 3 is protonated and then, through intra-molecular condensation of water, the cyclopentenone 4 is formed .
Individual evidence
- ↑ Heinz Hunsdiecker: About the behavior of γ ‐ diketones, 1st communication In: Ber. German Chem. Ges. 75, 1942, pp. 447-454, doi: 10.1002 / cber.19420750502 .
- ↑ a b c Heinz Hunsdiecker: About the behavior of γ ‐ diketones, 2nd communication In: Ber. German Chem. Ges. 75, 1942, pp. 455-460, doi: 10.1002 / cber.19420750503 .
- ^ Zerong Wang: Comprehensive Organic Name Reactions and Reagents , Wiley, 2009, ISBN 978-0-471-70450-8 , pp. 1508-1510.