The preparation of macrocyclic polyether‐diester compounds by transesterification including the preparation of two new nitrogen containing diester‐crown compounds

Macrocyclic polyether‐diester compounds have been prepared by reacting oligoethylene glycols with the appropriate dimethyl esters in the presence of catalytic amounts of alkali metal methoxides. The methanol by‐product was removed by molecular sieves. Product yields were improved for the preparation of all macrocyclic compounds except a compound containing a furan subcyclic group (4). Six new macrocyclic diester compounds (7‐12) could only be prepared using the base catalyzed transesterification process since the acid chloride synthetic method failed or the acid chloride could not be made. The formation of compounds 5 and 6 from dimethyl 2, 6‐pyridine dicarboxylate (17) and the triethylene and tetraethylene glycols proceded by way of half‐transesterified intermediates. These intermediates were also observed for the base catalyzed decomposition of 5 and 6 in methanol to form the glycol and the diester 17.