32524-97-3Relevant academic research and scientific papers
Generation, Alkylation, and Silylation of Directed Enolates Formed by Reaction of Ketenes and Organolithium Reagents
Baigrie, Lynn M.,Lenoir, Dieter,Seikaly, Hani R.,Tidwell, Thomas T.
, p. 2105 - 2109 (2007/10/02)
Symmetrical ketenes R2C=C=O R2=t-Bu2(1), Et2(2),(CH2)4(3),(CH2)5(4) were reacted with organolithium reagents R'Li to give directed enolates R2C=C(OLi)R' which were alkylated with MeI or silylated with Me3SiCl.The silylation results for 2-4 were compared to those for reaction of ketones R2CHCO-n-Bu (16-18) with Me3SiCl and either i-Pr2NLi, KH, or Et3N.These latter conditions usually favored different regioisomers from the ketene route.Reaction of 1 with t-BuLi gave the previously inaccessible enolate t-Bu2C=C(OLi)-t-Bu (25), which on reaction with MeI gave a mixtureof the O-methylation product 27 along with some C-methylation product and with Me3SiCl gave the silyl enol ether 26.The vinyl ethers 26 and 27 are among the first substituted tri-tert-butylethylenes which have been reported.
