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Ch.11 - Reactions of Alcohols
Wade - Organic Chemistry 9th Edition
Wade9th EditionOrganic ChemistryISBN: 9780135213728Non è quello che usi tu?Cambia libro di testo
Capitolo 11, Problema 26a

Propose a mechanism for each reaction.
(a) Chemical reaction diagram showing a pentanol converting to an alkene with sulfuric acid and heat as catalysts.

Guida verificata passo dopo passo
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Step 1: Recognize the reaction type. This is an acid-catalyzed dehydration reaction where an alcohol is converted into an alkene using concentrated sulfuric acid (H₂SO₄) and heat.
Step 2: Protonation of the alcohol group. The hydroxyl group (-OH) on the cyclopentanol molecule is protonated by H₂SO₄, forming a good leaving group (water). The protonation step increases the electrophilicity of the carbon attached to the hydroxyl group.
Step 3: Formation of the carbocation intermediate. The protonated hydroxyl group leaves as water, generating a carbocation intermediate on the cyclopentane ring. This step is crucial for the subsequent rearrangement or elimination.
Step 4: Elimination of a proton to form the double bond. A base (often HSO₄⁻ or water) abstracts a proton from a β-carbon adjacent to the carbocation, leading to the formation of a double bond (alkene) in the cyclopentane ring.
Step 5: Verify the product. The final product is cyclopentene, an alkene formed by the elimination of water from cyclopentanol. The reaction follows Zaitsev's rule, favoring the most substituted alkene.

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