Cation template assisted oligoethylene glycol desymmetrization by intramolecular Cannizzaro reaction of topologically remote aldehydes

Oligoethylene glycol chains containing 2–5 ethylene glycol units, and possessing a benzyl alcohol and a benzoic acid end groups, can be quantitatively obtained by intramolecular Cannizzaro reaction of the corresponding remote benzaldehyde end groups. The process is quite effective if a complex with an appropriate cation is formed to allow the two aldehyde groups to be spatially confined near enough each other for the intramolecular redox process.