Metalation of alk-1-enes, using the mixture of butyllithium and potass
ium tert-butoxide in tetrahydropyran, followed by stereo-homogenizatio
n and ultimate treatment with chlorotrimethylsilane afforded a series
of alk-2-enyltrimethylsilanes in good yield and with (Z/E) ratios rang
ing from 95:5 to 98:2. The deprotonation of propene can be rapidly and
readily accomplished with a stoichiometric amount of the superbase su
spended in pentane on a 1 mol scale.