A simple one-pot entry to cyclic ethers of varied ring sizes from diols via phosphonium ion induced iodination and base catalyzed Williamson etherification

A novel and an efficient one-pot cyclization method using triphenylphosphine, iodine and a nitrogenous base has been established for the synthesis of cyclic ethers of various ring sizes. This appears to follow a two-step procedure, which includes preferential substitution of one hydroxyl group by an iodide generated in situ followed by an intramolecular ring closure through the attack of a free hydroxyl group or the more nucleophilic oxide ion.