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[3,3] Sigmatropic Rearrangement of Allyl Vinyl Ethers: Claisen Rearrangement

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有機化学
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JoVE Core 有機化学
[3,3] Sigmatropic Rearrangement of Allyl Vinyl Ethers: Claisen Rearrangement

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01:24 min

April 30, 2023

The Claisen rearrangement is a [3,3] sigmatropic rearrangement of allyl vinyl ethers to unsaturated carbonyl compounds. The rearrangement is a concerted pericyclic reaction proceeding via a chair-like transition state.

Figure1

An aromatic Claisen rearrangement involves the conversion of allyl aryl ethers to an unstable ketone intermediate, which tautomerizes to give ortho-substituted phenols.

Figure2

However, ortho-substituted allyl aryl ethers exclusively yield para-substituted phenols via two sequential Clasien rearrangements.

Figure3