Advices For Studying Organic Chemistry

A Me

chanism for the Reaction

Acid-Catalyzed Hydration of an Alkene
Step 1

C

CH 2

CH 3

H 3 C HO

H

H

+

ow H

3 CC

H 2 C

CH 3

H H

+ + OH

sl

The alkene accepts a proton to form the more stable 3° carbocation.

Step 2

C

CH 3

H 3 CCH 3

+

H

+ OH fast H 3 CC

CH 3

CH 3

H

OH

+

The carbocation reacts with a molucule of water to form a protonated alcohol.

Step 3

H

+ OH fast

H

H 3 CC + H OH+

CH 3

CH 3

H

OH

+

H 3 CC

CH 3

CH 3

OH

A transfer of a proton to a molecule of water leads to the product.

(^)

4. The rate-determining step in the hydration mechanism is step 1: the formation of
   the carbocation ⇒ accounts for the Markovnikov addition of water to the double

1) ore stable tert-butyl cation is formed rather than the much less stable

isobutyl cation in step 1 ⇒ tert-buty lcoho

bond.

The m

the reaction produces l a l.