Advices For Studying Organic Chemistry

R C O −Mg2+X −+ + MgX 2

Halomagnesium alkoxide

H OH

H

+ X− R C O H + OH

H

+

Alcohol

In the second step, the addition of aqueous HX causes protonation of the alkoxide

ion; this leads to the formation of the alcohol and MgX 2.

(^)

LCOHOLS FROM GRIGNARD REAGENTS

e a 1° Alcohol.

12.8 A

1. Grignard Reagents React with Formaldehyde to Giv

Rδ− MgXδ+ + H^3 O

alcohol

C

H

O C O

H

R C OH

H

R

Fromaldehyde

MgX

2. Grignard Reagents React with All Other Aldehydes to Give 2° Alcohols

H H + H

1 o

.

Rδ− MgXδ+ + H^3 O

alcohol

C

H

O C O

R' +

2 o

R'

H

R C OH

R'

H

R

Higher aldehyde

MgX

3. Grignard Reagents React with Ketones to Give 3° Alcohols.

+ H^3 O

δ− δ+ R' +

R MgX

alcohol

C

R"

O C O

R'

3 o

R"

R C OH

R'

R"

R

Ketone

MgX

4. Esters React with Two Molar Equivalents of a Grignard Reagent to Form 3°
   Alcohols.