SYNTHESIS OF VINYL ETHER COMPOUNDS BY PYROLYSIS OF DIMETHYL PERFLUORO-2,7-DIMETHYL-3,6-DIOXA-1,8-OCTANEDIOATE

Dimethyl perfluoro-2,7-dimethyl-3,6-dioxa-1,8-octa (1) is pyrolyzed ov er Na2CO3, K2CO3, CaCO3, BaCO3 and ZnO to give mixtures containing per fluoro-3,6-dioxa-1,7-octadiene (2) and methyl perfluoro-2-methyl-3,6-d ioxaoctanoate-7-ene (3). The pyrolysis conditions necessary to obtain these vinyl ethers require a higher temperature for the divalent metal compounds than for the monovalent. Increase in the pyrolysis temperat ure and decomposition time result in an increasing conversion of 1. At lower temperatures the pyrolysis product is mainly 3. However, the fo rmation of 2 increases with increasing decomposition temperature. Dime thyl carbonate was found in the decomposition product of the pyrolysis of 1 over Na2CO3, K2CO3.