3.5 methoxyethene (VI) were formed in small amounts (1.8 and 1.5%) respectively) in the sodium methoxide catalyzed addition to trifluoromethylacetylene. Assignments of stereochemistry and of structure are based primarily on nmr spectroscopy. The stereochemical assignments are based on ones made by Cullen and Dawson1* for the analogous compound VII. The nmr data are summarized in Table I.\/cF3 CF3 c= c
