抄録: A novel photochemical ring-contraction reaction of 5-unsubstituted 3, 1- benzoxazepines and their 5-halogeno or carboxyl derivatives to yield 3-formylindoles in an aprotic solvent is reported. This ring contraction was successfully extended to oxazepines having an alkoxycarbonyl function at the 5-position to give the indoles having this function at the 3-position. Though most of the oxazepines underwent the ring-contraction reaction ...