P-(benzyloxy)calix[8]arene synthesis revisited: P-(benzyloxy)calix[4]-, p-(benzyloxy)calix[5]-, p-(benzyloxy)calix[7]-, and p-(benzyloxy)bis(homooxa) calix[4]arenes

A detailed investigation of the 4-(benzyloxy)phenol/formaldehyde reaction shows that along with the previously described p-(benzyloxy)calix[8]arene and p-(benzyloxy)calix[6]arene, others calixarenes are observed and easily recovered on a preparative scale. All these new calixarenes are opening interesting perspectives for the synthesis of new supramolecular hosts, easily functionalized at the para position under very mild conditions and/or exhibiting a deep hydrophobic pocket. During the course of the synthesis of p-(benzyloxy)calix[8]arene, compounds 4-7 are easily recovered as byproducts on a preparative scale. Alkylation of these new calixarenes leads to the first functionalized derivatives.