High-yield calix[4]pyrroles as αβαβ isomers and X-ray structure analysis

Two calix[4]pyrroles as aβaβ isomers were prepared by the reactions of pyrrole with asymmetry ketones in high yields. In addition, two single crystals of calix[4]pyrrole 2 and 2·MeOH were solved by X-ray analysis, which further proved that either in free form or inclusion complex calix[4]pyrrole 2 is aβaβ isomer and adopts 1,3-alternate conformation.