Abstract: Reaction of unsymmetrical ketenes RR'C= C= O (4, R, R'= CMe,(CH,),; 8, R= Ph, R'= Me; 9, R= Ph, R'= Et; 10, R= Me3%, R'= Et; 11, R= t-Bu, R'= H) with organolithiums R” Li (R”= n-Bu, Ph, t-Bu, CH2= CH, HCEC) followed by silylation with Me3SiC1 gave stereospecific formation of a single silyl enol ether in each case. This result is interpreted in terms of preferential attack by the organolithium reagent in the plane of the ketene from ...
