SYNTHESIS OF SEVERAL DIESTER GROUP-CONTAINING CALIX[4]ARENES

Several ester group-containing calix[4]arenes were synthesized by the reaction of calix[4]arene and various acyl chlorides. Two or four ethy l succinyl units could be introduced into the calix[4]arene lower rim depending on the reaction conditions. But the mixture of three and fou r ethyl malonyl substituted calix[4]arenes were obtained and only thre e ethyl oxalyl units were introduced at the lower rim of calix[4]arene . interestingly when calix[4]arene was treated with ethyl oxalyl chlor ide in the presence of aluminum chloride, two ethyl oxalyl units were introduced at the upper rim of calix[4]arene. The conformation of thos e ester- containing calix[4]arenes was presented based on the H-1 and C-13 NMR spectra.