Intramolecular Acylating Reagent

El-Sayrafi and co-workers have reported on an intramolecular acylation reactions using diphosphoryl chloride 1. Diphosphoryl chloride (1) reacts with carboxylic acid 2 to give cyclic ketones 4 via the mixed acid anhydride 3. This reaction proceeds under mild conditions and within short period of time, and it give cyclic ketones in high yields. Also, 1 is used for phosphorylation, and has been used in various fields as a reaction reagent.