Furan undergoes electrophilic aromatic substitution more readily than benzene; mild reagents and conditions are sufficient.For example, furan reacts with bromine to give 2-bromofuran.(a) Propose mechanisms for the bromination of furan at the 2-position and at the 3-position. Draw the resonance forms ofeach sigma complex, and compare their stabilities.(b) Explain why furan undergoes bromination (and other electrophilic aromatic substitutions) primarily at the 2-position.O Br O123furan 2-bromofuran

Furan undergoes electrophilic aromatic substitution more readily than benzene; mild reagents and conditions are sufficient.For example, furan reacts with bromine to give 2-bromofuran.(a) Propose mechanisms for the bromination of furan at the 2-position and at the 3-position. Draw the resonance forms ofeach sigma complex, and compare their stabilities.(b) Explain why furan undergoes bromination (and other electrophilic aromatic substitutions) primarily at the 2-position.O Br O123furan 2-bromofuran

Organic Chemistry

8th Edition

ISBN:9781305580350

Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. Foote

Publisher:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. Foote

Chapter19: Enolate Anions And Enamines

Section: Chapter Questions

Problem 19.40P: Enamines normally react with methyl iodide to give two products: one arising from alkylation at...

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Write the formula of reagents used in the following reactions:(i) Bromination of phenol to 2,4,6-tribromophenol(ii) Hydroboration of propene and then oxidation to propanol.(b) Arrange the following compound groups in the increasing order of their property indicated:(i) p-nitrophenol, ethanol, phenol (acidic character)(ii) Propanol, Propane, Propanal (boiling point)
Furan undergoes electrophilic aromatic substitution more readily than benzene; mild reagents and conditions are sufficient.For example, furan reacts with bromine to give 2-bromofuran.Propose mechanisms for the bromination of furan at the 2-position and at the 3-position. Draw the resonance forms ofeach sigma complex, and compare their stabilities.
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Benzyl chloride undergoes bimolecular substitution with aqueous NaOH. (i) Deduce the rate law for this reaction. (ii) Outline the mechanism involved.
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The endiandric acids comprise a group of unsaturated carboxylic acids isolated from a tree that grows in the rainforests of eastern Australia. The methyl esters of endiandric acids D and E have been prepared from polyene Y by a series of two successive electrocyclic reactions: thermal ring closure of the conjugated tetraene followed by ring closure of the resulting conjugated triene. (a) Draw the structures (including stereochemistry) of the methyl esters of endiandric acids D and E. (b) The methyl ester of endiandric acid E undergoes an intramolecular [4 + 2] cycloaddition to form the methyl ester of endiandric acid A. Propose a possible structure for endiandric acid A.
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