| Pyrolysis at 280;Deuteration of the methyl group of vinylcyclopropane 29, and subsequent pyrolysis revealed isotope effects of 1.08 (.02) and 1.12 (.03) for the appearance of cyclopentene and diene products respectively. This result suggests diene formation occurs through the initial geometric isomerization of trans-29 to cis-29 and a subsequent (1,5) -sigmatropic shift. |
