N-Confused Calix
Next to the "normal" calix[4]pyrrole 1, the N-confused calix[4]pyrrole 2 is formed in substantial amounts (up to 22 % yield) as side product in the acid-catalyzed condensation reaction of ketones and pyrrole. In some cases, doubly N-confused calix[4]pyrroles are also formed.
Depraetere
S
Department of Chemistry, Katholieke Universiteit Leuven, Celestijnenlaan 200F, BE-3001 Heverlee (Belgium).
Smet
M
Dehaen
W