Improved conditions for the addition of alkoxides to di(ethylene glycol) di-p-tosylate: application to the stereospecific synthesis of the trans-isomers of dicyclohexano-18-crown-6

Conditions are defined for the efficient preparation of polyethers by direct condensation of ditosylates and alkoxides, and this approach is shown to provide a facile method for the synthesis of the trans-syn-trans (C) and trans-anti-trans (D) isomers of dicyclohexano-18-crown-6 (DCH18C6), one which both provides significantly improved yields and avoids the difficult separations required by certain previously described synthetic methods.