PURPOSE: To obtain a dibenzocyclooctane compound having an aldose reductase inhibiting activity, useful for a therapeutic agent for the complication of diabetes such as cataract, retinopathy, nervous disturbances, renal disturbances, etc., and an intermediate for the production of medicines such as an ameliorating agent for hepatic disturbances, etc.
CONSTITUTION: This dibenzocyclooctane compound of formula I (X is a halogen; R1 to R6 are each OH, a lower alkyloxy, a (substituted) benzyloxy, a (substituted) alkylcarbonyloxy or forming a lower alkylenedioxy group together with an adjacent group), e. g. (RS)-(Z) or (E)-2[2-bromo-4,5-dimethoxy-3-(4- nitrobenzyloxy)benzylidene}-3-(3,4,5-trimethoxybenzyl)butanolide, is obtained by reacting a hologenated butyrolactone compound of formula II in the presence of ferric perchlorate, etc., and trifluoroacetic acid in an organic solvent such as methylene chloride, toluene, etc., at approximately -10 to 30°C for 0.5-3hr.
TANAKA MASAHIDE
YAMAGUCHI TAKUJI
YOSHIDA RIE
