Profile for Syntheses along with gem buildings in the anhydride 4-oxa-tetra-cyclo-[5.3.Only two.10,Some.2009,10]dodec-11-ene-3,5-dione as well as the related imide 4-(4-bromo-phen-yl)-4-aza-tetra-cyclo-[5.Three.Two.10,Some.'08,10]dodec-11-ene-3,5-dione. (toiletsort7)