Reactions of carbonyl compounds
(a) oxidation of aldehydes using Cr2O7 2–/H+ (i.e. K2Cr2O7/H2SO4) to form carboxylic acids
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(b) nucleophilic addition reactions of carbonyl compounds with:
(i) NaBH4 to form alcohols
(ii) HCN [i.e. NaCN(aq)/H+(aq)], to form hydroxynitriles
(c) the mechanism for nucleophilic addition reactions of aldehydes and ketones with NaBH4 and HCN
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Characteristic tests for carbonyl compounds
(d) use of 2,4-dinitrophenylhydrazine to:
(i) detect the presence of a carbonyl group in an organic compound
(ii) identify a carbonyl compound from the melting point of the derivative
(e) use of Tollens’ reagent (ammoniacal silvernitrate) to:
(i) detect the presence of an aldehyde group
(ii) distinguish between aldehydes and ketones, explained in terms of the oxidation of aldehydes to carboxylic acids with reduction
of silver ions to silver.
