Stereoselective preparation of mono- and bis-derivatives of pentacyclo[6.3.0.02,6.03,10.05,9] undecane (D 3-trishomocubane)

The rearrangement of easily accessible Cookson’s diketone with chlorosulfonic acid in chloroform followed by the acidic hydrolysis gave 6-chloro-7-hydroxy-dichloropentacyclo[6.3.0.0^2,6.0^3,10.0^5,9]undecane-4-one, whose syn-stereochemistry was assigned through the X-ray crystal structure analysis. This key structure was used for the stereoselective synthesis of the D ₃-trishomocubane derivatives as well as for the preparation of potential drugs bearing hydroxy- and amino-functional groups. A new multigram preparative synthesis of D ₃-trishomocubane was developed.