The cross-metathesis of vinyltrialkoxy- and vinyltrisiloxysilanes as well as divinyltetraethoxydisiloxane with various allyl alkyl ethers catalyzed by Cl2(PCy3)2Ru(CHPh) (I) is presented. The reaction is accompanied by self-metathesis of allyl alkyl ethers. The catalytic examination presented in this paper has allowed us to develop optimum conditions for selective synthesis of 1-silyl-3-alkoxy-propenes (R‘O)3SiCHCHOR (where R = Et, n-Bu, Cy, Ph, PhCH2, Gly, Me3Si, R‘ = Me, Et, SiMe3) with high preference of the E-isomers (E/Z > 7:1). This allowed the selective isolation of the E-isomer. A stoichiometric study of I with substrates has been carried out. The results are discussed on the basis of a metallacarbene mechanism.