Intramolecular acylation of aryl- and aroyl-aliphatic acids by the action of pyrophosphoryl chloride and phosphorus oxychloride

Both pyrophosphoryl chloride and phosphorus oxychloride react: with aryl aliphatic acids to form mixed anhydrides which undergo intramolecular acylation to afford cyclic ketones without the addition of a Friedel-Crafts catalyst. Aryl and aroyl-benzoic acids could be cyclized to the corresponding anthrones and anthraquinones respectively.