A NEW APPROACH TO THE SYNTHESIS OF PHENOL CONTAINING MACROHETEROCYCLES

A one-step method for the synthesis of new phenol-containing cryptands and cryptohemispherands by treating N,N'-bis(methoxymethyl)diazacrown s with the appropriate bis- and trisphenols is reported. This method, based on a special Mannich reaction, gives cyclized products without-t he need for protecting groups and high dilution conditions. Unusually high yields of cryptohemisherands were realized using a relatively hig h concentration of the starting materials (50 mmol/L) and in the absen ce of metal cations as template agents in the reaction mixture. These excellent yields can be explained by intramolecular hydrogen bonding w hich prevents polycondensation. This new method also allowed preparati on of new phenol-containing cylindrical tricyclic ligands by first for ming bisphenol-substituted diaza-18-crown-6 at 80 degrees C followed b y its reaction with a second bis(methoxymethyl)-substituted diaza-18-c rown-6 at 144 degrees C. Crystal structures of two cryptohemispherands are reported herein. A shorter internal distance between N and O atom s in 27 as compared to 6 (R = NO2, n = m = 2) indicates intramolecular hydrogen bonding in phenol-containing macrocycle 27.