Cyclic Oligofurans: One-Pot Synthesis of 30π and 40π Expanded Porphyrinoids

Acid-catalyzed condensation of furan and pentafluorobenzaldehyde yielded conjugated macrocycles with six and eight furan rings. They
represent systems similar to annulenes with 30π and 40π electrons. From their structural analyses, it was found that furan rings in both the
molecules were inverted in an alternative fashion and displayed nontwisted conformations.