Synthesis and Conformational Properties of Bis(calix[4]arene)

The bis(calix[4]arene) 3 was synthesized in moderate yield by the reaction of p-tert-butylcalix[4]arene (1) with 1,4-bis(chloromethyl)benzene (2). The conformation of all alkylated product 4 was investigated by the variable-temperature 1H-NMR.