Intermediates for the synthesis of olivin and rhodomycinone were prepared by a sequence involving a Diels-Alder reaction followed by a Friedel-Crafts cyclization. In all cases optimal yields were obtained by regioselective methanolysis of anhydrides 9,10, and 21 followed by treatment of the crude ester acids with trifluoroacetic anhydride. An added advantage of the latter reaction is that aromatization also occurs.