A general approach toward Janus diones: synthesis of dicyclopenta[b,g]naphthalene-1,3,6,8(2H,7H)-tetraone

A general approach toward Janus diones involving the reaction of pyromellitic or naphthalenetetracarboxylic dianhydrides with ethyl(triphenylphosphoranylidene)acetate and subsequent rearrangement of the products is described. This approach allows avoiding the formation of poorly soluble intermediates, in which purity cannot be effectively controlled. Dicyclopentab,g]naphthalene-1,3,6,8(2H,7H)-tetraone 3, a promising precursor of molecular and polymeric advanced materials is described.