Also known as: Claisen-Ireland rearrangement
![Schematic of the Ireland-Claisen rearrangement. Reagents: allyl ester, LDA, TMSCl, NaOH, water. Product: γ,δ-unsaturated carboxylic acid. Comments: Concerted [3,3]-sigmatropic rearrangement.](https://img.rnalibrary.com/rnalibrary/ireland-claisen-rearrangement-s-357dcfe757c38e1bb98195a0616c3e53.svg)
The Ireland-Claisen rearrangement is an organic reaction used to convert an allyl ester to a γ,δ-unsaturated carboxyl acid using LDA, TMSCl, and NaOH/H2O. The reaction begins with deprotonation of the α-hydrogen of the ester to form an enolate which then attacks TMSCl to stabilize the charge and produce LiCl salt. The two olefin groups are ideally positioned for a Claisen rearrangement, which results in the formation of a carbonyl group. Deprotection of the TMS group with base and protonation then results in the final carboxylic acid product. 3-(Hydroxymethyl)pyrrolidin-2-one Purity Buy(E)-3-(Thiazol-4-yl)acrylic acid [1][2][3]
Mechanism
References:
| 1. |
Ireland, R. E.; Mueller, R. H. J. Am. Chem. Soc. 1972, 94, 5897–5898.
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| 2. |
Ireland, R. E.; Willard, A. K. Tetrahedron Letters 1975, 16, 3975–3978.
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| 3. |
Ireland, R. E.; Mueller, R. H.; Willard, A. K. J. Am. Chem. Soc. 1976, 98, 2868–2877.
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