Functional Classes II, Reactions - Organic Chemistry Concepts: An EFL Approach - page 118

FIGURE 7.25
Nucleophilic addition.

Aldehydes are generally more reactive than ketones. As Figure 7.26 shows, a
ketone has more positive inductive effects than an aldehyde. As discussed in
Chapter 2, this affects the extent of dipolar character of the carbonyl group.
Because of this, aldehydes have greater dipolar character. Therefore, they are
more reactive to nucleophiles than ketones.

FIGURE 7.26
The relative inductive effects in aldehydes and ketones.

Table 7.3 lists different nucleophilic addition reactions to carbonyl compounds.
These are a very important set of functional group interconversions.

Table 7.3 Nucleophilic Addition to a Carbonyl RR 1 C ] O
Addition Reagent

Product Class

R OH

Hydrogen cyanide

HCN C

Cyanohydrin

R 1 CN

R

O H

H 2 O

Water

C

Hydrate

R 1 OH

OR 2 R

R 2 OH

Alcohol

C

Acetal

R 1 OR 2

R

O H

Hydrogen

C

Alcohol

H /H

R 1 H

R OH

R 2 M g X

Grignard

C

Alcohol

R 1 R 2

R

R 2 NH 2

Amine

NR 2

Imine

R 1