The Friedel–Crafts reactions of benzene with hex-3-en-2-one, hex-4-en-2-one, hex-5-en-2-one, hept-3-en-2-one, hept-4-en-2-one, oct-3-en-2-one, oct-4-en-2-one, oct-5-en-2-one, oct-6-en-2-one, oct-7-en-2-one, and 5-methylhex-5-en-2-one are reported. Hex-4-en-2-one and hex-5-en-2-one both yielded 5-phenylhexan-2-one as the sole monophenylation product. Each of the other ketones gave a mixture of phenylated alkanones, the composition of which depended on the position of the double bond relative to the carbonyl group in the starting ketone.