Regiodivergent synthesis of trisubstituted furans through Tf<sub>2</sub>O-catalyzed Friedel–Crafts acylation: a tool for access to tetrahydrofuranlignan analogues
of the ring-chain tautomerism occurring in compounds equipped with two neighbouring carboxylic functions. Since 4-aroylfuran derivatives show a typical lignan backbone, suitable hydrogenation conditions were found out to gain tetrahydrofuranlignans.