All melting points are uncorrected. Microanalyses were carried out by AB Gygli Microanalysis Laboratory. lH NMR spectra were run on a Varian T-60 or HA, 100 spectrometer. I3C NMR spectra were run on a Varian CFT-20 spectrometer using a 16K memory. Chloroform-d was used as an internal lock and reference. All spectra were referenced to Me& as an internal standard. The olefins were obtained commercially and ...