Formation of hybrid polymethylene–poly(oxyethylene) macrocycles

Macrocyclisations, particularly those forming crown ethers, normally require high dilution conditions. However, treatment of 1,9-bis(sarcosylamino)nonane with α,ω-bis(oxiranylmethyl) ethers derived from oligomeric poly(ethyleneglycol)s of MW 400–600 Da under high concentration conditions was found to give excellent yields of 1:1 hybrid polymethylene–poly(oxyethylene) macrocyclic crown ether derivatives. The corresponding α,ω-bis(oxiranylmethyl) ether derived from poly(ethyleneglycol) of mean MW 1500 Da gave polymeric material only. The macrocycles were characterised by NMR, GPC and MS.