Reactions of Carbonyl Compounds Simple Reversible Additions

6 Reactions of Carbonyl Compounds Simple Reversible Additions 

FIGURE 16.19 Addition of water to an alkene to give an alcohol is analogous to addition to a ketone or aldehyde to give a hydrate. 

If water acts as a nucleophile and adds to the Lewis acid carbonyl group, there is a choice to be made. In principle, water could add to either the carbon or the oxygen of the carbonyl group (Rg. 16.20). 

FIGURE 16.20 In principle, addition of water to a carbonyl group could occur in two ways. 

WORKED PROBLEM 16.7 Explain how the thermodynamic preference for placing a negative charge on oxygen, rather than carbon, can influence the rates of addition to the two ends of the carbon—oxygen double bond. 

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