Chapter 14 Aldehydes, Ketones, and Chiral Molecules 14.4 Addition Reactions of Aldehydes and Ketones

Addition Reactions When a polar molecule adds to the carbonyl group of an aldehyde or ketone, the negative part of the added molecule bonds to the positive carbonyl carbon the positive part of the added molecule bonds to the negative carbonyl oxygen

Addition Reactions (continued)

Acetal Formation Acetals are the product of two alcohols adding to the carbonyl groups of aldehydes and ketones.

Hemiacetal Formation A hemiacetal is an intermediate produced when one alcohol adds to the carbonyl group of an aldehyde or ketone usually unstable and difficult to isolate

Cyclic Hemiacetals In glucose, a cyclic hemiacetal between the C═O group and the —OH forms a stable, six-atom ring

Learning Check Identify each as a 1) hemiacetal or 2) acetal.

Solution Identify each as a 1) hemiacetal or 2) acetal. 1) hemiacetal

Learning Check Draw the condensed structural formula of the acetal formed by adding CH3OH to butanal.

Solution Draw the condensed structural formula of the acetal formed by adding CH3OH to butanal.