the use of C–C bond formation in synthesis to increase the length of a carbon chain (see also 6.1.1d, 6.1.2b)

formation of C–C≡N by reaction of:

(i) haloalkanes with CN^– and ethanol, including nucleophilic substitution mechanism (see also 4.2.2c)
(ii) carbonyl compounds with HCN, including nucleophilic addition mechanism (see also 6.1.2b–c)

reaction of nitriles from (b):

(i) by reduction (e.g. with H₂/Ni) to form amines
(ii) by acid hydrolysis to form carboxylic acids

formation of a substituted aromatic C–C by alkylation (using a haloalkane) and acylation (using an acyl chloride) in the presence of a halogen carrier (Friedel–Crafts reaction) (see also 6.1.1d).