6,7-Bis(bromomethyl)-2,11,18,21,24-pentaoxatetracyclo.

The 17-crown-5 unit, C(26)H(26)Br(2)O(5), consisting of a 1,2-bis(bromomethyl) group, three benzo groups and diethylene glycol, was prepared from the reaction of 1,2,4,5-tetrakis(bromomethyl)benzene and bis-phenol in the presence of sodium hydride as a base. This molecule seems to offer an internal cavity for the formation of a host--guest complex.