METHOD OF INHIBITING ALDOSE REDUCTASE ACTIVITY, COMPOSITIONS THEREFOR AND PROCESS FOR PREPARING SPIRO-FLUOROFLUOREN AND SPIRO-DIFLUOROFLUOREN COMPOUNDS

摘要

Accumulation of polyols in diabetic subjects causes and/or is associated with diabetic complications. Aldose reductase inhibition prevents the production of polyols. Aldose reductase activity is inhibited with tetracyclic spiro-hydantoins, which makes these compounds useful in the treatment of complications arising from diabetes mellitus. A process for preparing said tetracyclic spiro-hydantoins by reacting a mono- or di-fluorofluorene with an excess of oxygen and a tetralkyl- or arylalkyl-trialkyl-ammonium hydroxides followed by cyclization of the reaction product with ammonium carbonate and potassium cyanide at elevated temperature is also disclosed.