SYNTHESES OF 1-SUBSTITUTED 12-OXAHEXACYCLO[7.2.1.0(2,8).0(3,7).0(4,11).0(6,10)]DODECANES AND THEIR TRANSFORMATION INTO PENTACYCLO[6.3.0.0(2,6).0(3,10).0(5,9)]UNDECANE DERIVATIVES

The reaction of nucleophilic reagents (organomagnesium and organosodium compounds containing active methylene groups) with exo-11-bromopentacyclo[5.4.0.0(2,6).0(3,10).0(5,9)]undecan-8-one leads to the formation of 1-substituted-12-oxahexacyclo[7.2.1.0(2,8).0(3,7).0(4,11).0(6,10)] dodecanes which can be used in the synthesis of trishomocubane derivatives. It is shown, using the 1-methyl- and 1-phenyl-substituted 12-oxadodecanes, that iodotrimethylsilane readily cleaves the ether bond at C(l). The resulting carbonium ions rearrange to form 1,7,11-trisubstituted pentacyclo[6.3.0.0(2,6).0(3,10).0(5,9)]-undecanes.