Aldehyde
Nucleophilic addition reactions

Nucleophiles add readily to the carbonyl group. In the product, the carbonyl carbon becomes sp -hybridized, being bonded to the nucleophile, and the oxygen center becomes protonated:

In many cases, a water molecule is removed after the addition takes place; in this case, the reaction is classed as an addition – elimination or addition – condensation reaction. There are many variations of nucleophilic addition reactions.
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