Studies in the synthesis of Furocoumarins. Part XXI : Synthesis of Furocoumestan derivatives

Chemistry Department, Faculty of Science., M. S. University of Baroda, Baroda-2 Manuscript received 9 November 1972 ; accepted 5 December 1973; accepted 18 November 1974 7-Allytoxy-4-hydroxycoumarin, on dehydrogenative coupling with catechol in the presence of potassium iodate gave 7-allyloxy-11, 12-dihydroxy coumestan ; which on methylation followed by Claisen migration, cyclisation with conc. sulphuric acid and dehydrogenation with palladised charcoal furnished 5`-methyl-11,12-dimethoxy furo (2,3-h) coumestan. 5',8-Dimethy1-11,12- dimethoxy furo (3,2-g) coumestan was similarly synthesised from 7-allyloxy-8-methy1-4-hydroxy­coumarin