Reaction of the appropriate compound XXII with a glycol of the formula, ##STR50## wherein and subsequently elsewhere, X is an oxygen or sulfur atoms, Q is a hydrogen atom or alkyl group having 1-2 carbon atoms and k is either 0 or 1, under acid catalysis under reflux (e.g., p-toluene sulfonic acid) yields the corresponding alkyl ketoalkanote-ketal, XXIV (step A, Table C).