Preparation:

Functional group transformations

Functional group transformations permit the conversion of a functional group to an aldehyde or a ketone without influencing the carbon skeleton of the molecule. Aldehydes can be synthesized through the oxidation of primary alcohols, or through the reduction of esters, acid chlorides, or nitriles. Because nitriles can be acquired from alkyl halides, this is a mode of adding an aldehyde unit (CHO) to an alkyl halide.

Figure: Synthesis of an aldehyde from an alkyl halide with 1C chain extension.

Ketones can be synthesized through the oxidation of secondary alcohols. From terminal alkynes methyl ketones can be synthesized.