ZaballosGarcia, E,GonzalezRosende, ME,JordaGregori, JM,SepulvedaArques, J,Jennings, WB,OLeary, D,Twomey, S;

1997

July

Tetrahedron

Ring transformation of furfural into an unusual bicyclic system: Characterisation and dynamic stereochemistry of 6,7-diethoxycarbonyl-6,7-diaza-8-oxabicyclo[3,2,1]oct-3-en-2-one.

Validated

()

53

9313

9322

2-Formylthiophene and 3-formylindole react with diethyl azodicarboxylate to give simple products derived from reactions on the formyl group whereas 2-formylfuran reacts to give the unexpected bicyclic title compound. H-1 and C-13 NMR Studies indicate that this compound undergoes a series of three dynamic conformational changes over the temperature range 50 to -90 degrees C which are ascribed to slow rotation about the exocyclic carbamate bonds and hindered bridge inversion. (C) 1997 Elsevier Science Ltd.