Formation of novel polycyclic cage compounds through 'uncaging' of readily accessible higher cage compounds

The synthesis of the novel cage compounds 7-halomethyl-8-(carbomethoxy)tetracyclo[4.2.1.14,7.02,5]deca-3-(11)-ene-10-ones, methyl-4-methylene-6-oxopentacyclo[5.4.0.0.2,5.03,10.07,9]undecane-9-carboxylate, 3-chloromethyl-4-(carbomethoxy)tetracyclo[4.2.1.1.3,8.02,5]deca-7(11)ene-10-one, 2-bromo-5-methyl-8-methylene-6-oxotricyclo[5.3.0.03,9]decane-4-carboxylic acid and 2-bromo-5-methyl-8-methylene-6-oxotricyclo[5.3.0.03,9]decane-4-methyl carboxylate, achieved through base catalyzed rearrangement, is described.