Reactions involving fluoride ion. Part 29. Reactions of perfluoro-2,3-dimethylbuta-1,3-diene
Abstract
Reactions of perfluoro-2,3-dimethylbutadiene (1) with methanol, phenol, and sodium methoxide yield products arising from substitution; with methanol a 1,2-addition product is also observed. Reactions of (1) with enolate anions derived from ethyl acetoacetate and acetylacetone yield pyran derivatives, and an oxepine. The diene (1) undergoes free radical addition with methanol, and cycloaddition with diazomethane. Except under strongly nucleophilic conditions, reactions occur at only one of the double bonds of the diene (1) and, on the basis of this and u.v. spectral data, the diene (1) is considered to be conjugated, contrary to other conclusions.