Term
| The _________ of alcohols is a common method for making alkenes; the term literally means the "removal of water." |
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Definition
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Term
_________ is a reversible reaction with a small equilibrium constant.
In fact, the reverse reaction (__________) is a method for converting alkenes to _________. |
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Definition
1) Dehydration
2) Hydration
3) Alcohols |
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Term
Concentrated _________ or _________ acid are often used as reagents for _________ because these acids act both as _________ _________ and as _________ agents.
Hydration of these acids is strongly _________. |
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Definition
1) Sulfuric
2) Phosphoric
3) Dehydration
4) Acidic catalysts
5) Dehydrating
6) Exothermic |
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Term
The mechanism for dehydration resembles the _________ mechanism introduced earlier:
The _________ group of the alcohol is a (poor/good) leaving group, but protonation by the _________ _________ converts it to a (poor/good) leaving group.
In the second step, loss of _________ from the protonated alcohol gives a carbocation.
The carbocation is a very strong _________: any weak base such as water or HSO4- can abstract the _________ in the final step to produce an alkene. |
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Definition
1) E1
2) Hydroxide
3) Poor
4) Acidic catalyst
5) Good
6) Water
7) Acid
8) Proton |
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Term
*Acid-Catalyzed Dehydration of an Alcohol*
Step 1: Protonation of the _________ group (_________ equilibrium).
Step 2: Ionization to a _________ (_________, rate-limiting).
Step 3: Deprotonation to give the _________ (_________). |
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Definition
1) Hydroxyl
2) Fast
3) Carbocation
4) Slow
5) Alkene
6) Fast |
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Term
Like other _________ reactions, alcohol dehydration follows an order of reactivity that reflects carbocation stability:
_________ > _________ > _________
_________ of the carbocation intermediates are common in alcohol dehydrations.
In many cases, _________ _________ applies: the major product is usually the one with the most substituted double bond. |
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Definition
1) E1
2) 3° > 2° > 1°
3) Rearrangements
4) Zaitsev's Rule |
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