Synthesis of p-tert-butyl-calix[6]-biscrown-3 via intramolecular ring-closure of 1,4-bis(2-(2-chloroethoxy)ethoxy)-p-tert-butyl-calix[6]arene

With a variation in reaction conditions, 1, 4-bis(2-(2-chloroethoxy)ethoxy) -calix[6]arene (3) and 1,3,5-tris(2-(2-chloroethoxy) ethoxy)-calix[6] arene (4) or 4 and 4-chloroethoxy ethoxy-calix[6] crown-3 (5) were selectively s ynthesized from p-tert-butyl-calix [6] arene and 2-(2-chloroethoxy) ethylto sylate. 1,3-4,6-p-tert-butylcalix[6] -biscrown-3 (6) with (u,u,u,d,d,d) con formation and 1,3-4,5-p-tert-butylcalix[6]-biscrown-3 (7) with self-anchore d (u,u, u, u, u, d) conformation were synthesized through an Intramolecular ly ring-closing condensation of 1, 4-bis(2-(2- chloroethoxy) ethoxy)-p-tert -butyl-calix[6] arene (3) in 25% and 15% yield, respectively. Using 5 inste ad of 3, only 7 was obtained In 65% high yield. 6 and 7 show different comp lexation properties toward alkali metal and ammonium ions.