2. H, O+ HC0, H and mass spectral data as well as by elemental analysis. The gemdimethyl group of all three olefins appeared as a singlet at 7 8.20-8.23. With the exception of ala'- dimethylstilbene 3a which was prepared from l-phenylethyl chloride by the method of Kharasch and Kleiman, 4 the other olefinic products which would result from the migration of methyl to the carbene center were conveniently synthesized by the sequence of reactions ...