3-benzoyl derivative (IIa) could be directly prepared from (I) using an equivalent mole of benzoyl chloride in the presence of an excess of aluminum chloride in nitrobenzene

compound possessing the acyl group in the 3-position of DHA nucleus 〔triacetic acid lactone (TAL)〕, the derivatives having the aroyl instead of the acyl group in the 3-position have never been synthesized. In order to investigate the activity which the carbonyl group in their side chain displays for of various primary amines and their antibacterial activity, some new DHA type derivatives possessing the aroyl group were attempted to synthesize, and the details of these synthesis and their reaction processes are described below. It was already attempted 3) to synthesize 3-benzoyl derivative of DHA by FriedelCrafts reaction of TAL (I) and benzoyl chloride in the presence of a suitable condensing agent, for example, a few drops of conc. sulfuric acid, pyridine-piperidine or an equivalent mole of aluminum chloride, but without success. In the cases when pyridine-piperidine or an equivalent mole of aluminum chloride was used as the candensing agent, a monobenzoate (IIIa), m.p. 91°, was obtained, while