The synthesis of cis- and trans-2,4-Di-n-octyltetrahydrofuran: Models for the disubstituted cyclic ether groups in reduced poly(vinyl chloride-co-carbon monoxide).

2,4-disubstituted tetrahydrofuran groups have been observed in the backbone of carbon monoxide-vinyl chloride copolymers that had been reduced sequentially with lithium aluminum hydride (LAH) and tri-n-butyltin hydride. These cyclic ether structures are believed to arise from the intramolecular nucleophilic displacement of adjacent chloro substituents by intermediate metallic alkoxides formed during the LAH reduction of the pendant acyl chloride (or carbomethoxy) groups of the copolymers. The title compounds were used to obtain reference chemical shift data and were synthesized using a novel route, recently developed in our laboratories, that includes a simple and efficient method for the preparation of 3-substituted furans.