STRUCTURE AND CONFORMATION OF STEREOISOMERIC C-ISOPROPOXYCARBONYLMETHYLCALIX[4]RESORCINARENES

Abstract

Treatment of (E)-2,4-dimethoxycinnamic acid isopropyl esters with boron trifluoride-diethyl ether in chloroform at room temperature affords various stereoisomeric C-alkylcalix[4]resorcinarenes, which differ in their conformations; the crystal structures of two stereoisomers have been determined and compared with geometries resulting from theoretical calculations