A Modified Synthesis of Dibenzo-18-Crown-6-Polyether and Related Macrocycles

Abstract
The synthesis of crown polyethers of the type I involves the stepwise treatment of catechol with 2,2′-dichloroethyl ether or its oxyethylene homologues.1,2 The commercial unavailability of the higher chloroethers coupled with the inherent danger involved in the handling of such compounds3 led us to investigate the use of the crystalline di-tosyl derivatives (II and III) of digol4 and trigol5 in such condensations. Dale and Kristiansen6 have used the di-tosyl derivatives II and III in the preparation of cyclic oligo-ethers although application to the benzo-fused crowns was not described.