BENZYLIC OXO-FUNCTIONALISATION OF INDANE DERIVATIVE BY BENZYLIC BROMINATION FOLLOWED BY KORNBLUM-TYPE OXIDATION

摘要

1,1'-Dimethoxy-1,1'-diphenyl-2,2'-spirobiindane and indane, as a model compound, were treated with various oxidising agents in order to achieve benzylic oxo-functionalisation. The model compound, indane, was successfully converted directly to 1-indanone, using several benzylic oxidation procedures, but when they were used on the 1,1'-dimethoxy-1,1'-diphenyl-2,2'-spirobiindane derivative, they either failed, led to fragmentation or complex mixture of products was obtained. The benzylic oxo-functionalisation was achieved on the 1,1'-dimethoxy derivative in two steps using benzylic bromination/silver-assisted Komblum type oxidation. The observed reactivity of these systems can be rationalised by steric hindrance arguments and the ring opening tendencies of the 1,1'-disubstituted-1,1'-diphenyl-2,2'-spirobiindane derivatives.