Symmetrical ketenes R2C= C= 0 [&= t-Bu2 (l), Eh (21,(CH,),(3),(CH& (4)] were reacted with organolithium reagents R'Li to give directed enolates R, C= C (OLi) R'which were alkylated with Me1 or silylated with Me3SiC1. The silylation results for 2-4 were compared to those for reaction of ketones R2CHCO-n-Bu (16-18) with Me, SiCl and either i-PrzNLi, KH, or EgN. These latter conditions usually favored different regioisomers from the ketene route. ...