New Application of Crown Ethers. III. Synthesis of 4′-Hydroxybenzocrown Ethers and Their Bis(benzocrown ether)s Linked by Poly(oxyethylene) Chain

Baeyer-Villiger oxidation of 4′-acetylbenzocrown ethers followed by alkaline hydrolysis was proved to be a convenient route to 4′-hydroxybenzo-15-crown-5 and -18-crown-6, which formed air-stable hydrated crystals containing three and one mole of water, respectively, on crystallization from the solvent containing a small amount of water. New bis(benzocrown ether)s, connected by poly(oxyethylene) chain, were obtained in good yields by the reaction of the sodium salts with the ditosylates of di-, tri-, tetra-, and pentaethylene glycol.