Synthesis of glycidyl calixarenes, versatile substrates for the preparation of chiral calixarene-based ligands

Abstract

The first calixarenes bearing chiral glycidyl groups at the lower rim have been obtained by treatment of p-tert-butylcalix[4]arene ( 1a) and p-tert-butylcalix[6]arene ( 1b) with glycidyl tosylate or 3-nitrobenzenesulfonate in the presence of a base. Their structure was established as syn-1,3-diglycidyl calix[4]arene 2, tetraglycidyl calix[4]arene 3 (partial cone, 1,2-alternate and 1,3-alternate conformers), and 1,2,4,5-tetraglycidyl calix[6]arene 4, respectively, by 1H and 13C NMR spectroscopy. Regio- and stereoselective epoxide ring-opening of 2 with amines led to chiral β-aminoalcohols ( 5 and 6).