The preparation and properties of cage polycyclic systems—III: The cleavage in alkaline conditions of acetals derived from pentacyclo[5.3.0.02,5.03,9.04,8]decane and pentacyclo[4.3.0.02,5.03,8.04,7]nonane systems
in pentacyclo5.3.0.02,5.03,9.04,8]decane and pentacyclo4.3.0.02,5.03,8.04,7]nonane systems to give the methylene group is shown to occur in alkaline conditions in the presence of hydrazine. Evidence is presented for a mechanism which involves initial cleavage of the acetal by alkali to form the ketone. The substitution of a Br atom in the position neighbouring the CO group of 5-bromo-6,6-ethylenedioxypentacyclo5.3.0.02,5.03,9.04,8]decan-10-one facilitates the Wolff-Kishner reaction to such an extent that hydrazine hydrate is a sufficiently strong base to induce the decomposition of the hydrazone directly.
