The Diels-Alder reaction of dimethyl furandicarboxylate 6 with DMAD is investigated and the exo-exo bisadduct 8 is fully characterized. Monoadduct 7, 8, and test system 12 are cyclopropanated with diazomethane giving 10, 11, and 14. Then 7, 8, and 12 are treated with the “latently acceptor substituted” diazomethane 17. After appropriate transformations cyanocyclopropyl derivatives 18 and 19 are obtained from 7 and 12. Unexpectedly, 8 also ...