Regio- and stereoselective synthesis of pterocarpan derivatives on a carbazole scaffold by cascade sigmatropic rearrangements
Thermal rearrangement of 1-aryloxy-4-carbazolyloxy-but-2-ynes, regio- and stereoselectively led to the formation of benzofuropyranocarbazoles in a single step in good yields. An investigation into the mechanism of the formation of these heteroannulated pt