Synthesis of 1-substituted 12-oxahexacyclo[7.2.1.02,8.03,7.04,11.06,10]dodecanes and their transformation into pentacyclo[6.3.0.02,6.03,10.05,9]undecane derivatives

Abstract

The reaction of nucleophilic reagents (organomagnesium and organosodium compounds containing active methylene groups) with exo-II-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 ]dodecanea in the synthesis of trishomocubane derivatives. It is shown, using the 1-methyl- and 1-phenyl-substituted 12-oxadodecanes, that iodotrimethylsilane readly cleaves the ether bond at C(1). The resulting carbonium ions rearrange to form 1,7,11-trisubstituted pentacyclo[5.4.0.0 2,6 .0 3,10 .0 5,9 ]undecane