Cycloaddition reactions of thiazolidine derivatives. An approach to the synthesis of new functionalized heterocyclic systems

A one-pot procedure for the synthesis of two functionalized tricyclic systems having structures of benzo[g]isoquinoline-5,10-dione and dihydrothieno[2,3-b]naphto-4,9-dione (DTNQ) is described. These new series were synthesized from cycloaddition reactions between naphthoquinone and arylthiazolidine derivatives, the latter acting, respectively, as highly reactive N-arylidenedehydroalanine ethyl esters (2-AD) or as amino ester nucleophilic species.