The influence of hydrate formation on the Clemmensen reduction of pentacyclo [5.4.0.02,6;03,10;05,9]undecane-8,11-dione and pentacyclo[6.4.0.02,7.03,11.06,10]dodecane-9,

Article abstract of DOI:10.1016/S0040-4020(01)96209-X

Hydration of pentacyclo [5.4.0.0^2,6,0^3,10.0^5,9]undecane-8,11-dione led to the formation of a mixture of a geminal diol (80%) and a transannular hydrate (20%) and not to only the latter as previously accepted. Compounds with smaller intercarbonylic distances formed only transannular hydrates which promoted rearrangement reactions during Clemmensen reduction. The transannular hydrate of pentacyclo [6.4.0.0^2,7.0^3,11.0^6,10]dodecane-9,12-dione produced pentacyclo [6.4.0.0^2,6.0^5,9.0^4,12]-2-dodecanol.