“…Thus, aiming for the application of ortho-formyl acids, in recent years, a number of works have been published. For example, new protocols for the synthesis of 3-difluoroalkyl phthalides [1], 3-benzylphthalides [2], 3-(1 -indolyl)phthalides [3], and electrochemical protocol for isoindolinones [4] were developed. Syntheses of (+)-Rubellin C [5], benzo[f]pyrrolo [1, 2-a] [1,4] diazepines [6], fluorinated isocoumarines [7], furo [2,3-d]pyridazines [8], furo [3,4-c]pyridines [9], 1-oxo-9H-thiopyrano [3,4-b]indoles [10], pyrazoloisoindoles [11], phthalazines [12] and isothiocoumarines [13] were studied.…”