-exo-Dibromo-3-methyl-3,6-endo-oxyperhydrophthalic anhydride 3b and en
do-dibromo-3-methyl-3,6-endo-oxyperhydrophthalic anhydride 3c were iso
lated from the bromo-adducts of 3-methyl-3,6-endo-oxy-1,2,3,6-tetrahyd
rophthalic anhydride 2. When 3b or 3c was heated in quinoline, only 3-
bromo-2-methyifuran 4 was obtained from 3b and only 4-bromo-2-methylfu
ran 5 from 3c.