Preparation of ketones by insertion of diazo compounds into the formyl C-H bond of an aldehyde is an attractive procedure, but use of structurally diverse diazo compounds is hampered by preparation and safety issues. A convenient procedure for the synthesis of unsymmetrical ketones from bench-stable tosylhydrazones and aryl aldehydes is reported. The procedure can be performed in one pot from the parent carbonyl compound and needs only a base, with no additional promoters being required.