Multiple pathways to ring-contracted aromatic hydrocarbons

Abstract

The conversion of 3-phenylphthalic anhydride into cyclopent[a]indene (benzopentalene) by flash vacuum pyrolysis (FVP) is not unique; eighteen biphenyl-based anhydrides, allyl esters and bis-allyl esters can form benzopentalene .Similarly, triphenylene derivatives with 1,2-, 1,3 -, 1,4- and 2,3- anhydride or bis-allyl ester functions form cyclopent[h,i ]acephenanthrylene on FVP.