10-bromo-3-oxatricyclo[7.3.1.0^{5,13}]trideca-1(13),5,7,9,11-pentaene-2,4-dione
8-bromo-3-oxatricyclo[7.3.1.0^{5,13}]trideca-1(13),5,7,9,11-pentaene-2,4-dione
8-bromo-3-oxatricyclo[7.3.1.05,13]trideca-1(13),5,7,9,11-pentaene-2,4-dione
10-bromo-3-oxatricyclo[7.3.1.05,13]trideca-1(13),5,7,9,11-pentaene-2,4-dione