Addition Reactions to Carbon/Oxygen Double Bonds
In this chapter, the authors look at addition reactions to another very common multiple bond system, namely the carbon/oxygen double bond. This system differs quite significantly from the carbon/carbon multiple bond system, primarily because there is an inherent dipole across the bond. The authors also look at the reactions of a carbonyl group that is joined to hydrogen atoms or alkyl groups, that is, aldehydes and ketones. Such carbonyl compounds undergo addition reactions. Many of the addition reactions that a carbonyl group undergoes are reversible, and so the thermodynamic product is formed. However, in addition to examining which is the favoured product, it is interesting to study the kinetics of the reaction. The addition of an alcohol molecule follows a similar pattern to the addition of water. Draw the mechanism for the addition of ethanol to ethanal under general acid catalysis conditions.