Centropentaindan: synthesis and some bridgehead transformations of a novel regular centropolyindan

Abstract

The synthesis of a novel centropentacyclic hydrocarbon, centropentaindan 1, has been achieved by fourfold bromination of the readily available difuso-triindan 4 followed by AlBr₃-catalysed condensation with two molecules of benzene; functionalization of the two remaining tertiary bridgehead positions of 1 gives the strained, labile dibromide 6, which has been converted into the dimethyl derivative 7, the centrohexacyclic endoperoxide 8, and, again by AlBr₃-catalysed condensation with benzene, into centrohexaindan 2.