The order of addition of salt-free ethyllithium/benzene solution to enantiomerically pure acylketene acetal 1 dictates the product formed in a chemospecific manner. Introduction of lithium bromide removes the distinction.
Enantiomerically pure ketals in synthesis. Diastereoselective formation of β-keto and β-hydroxy ketals
作者:Clark N. Eid、Joseph P. Konopelski
DOI:10.1016/s0040-4039(00)79468-8
日期:1991.1
Enantiomerically pure acylketene acetals were employed to generate a homochiral β-keto ketal through a highly diastereoselective lithium enolate quench. The β-keto ketal, which was also prepared through a desymmetrization ketalization reaction on a meso dione, was employed in the synthesis of the isomers of the insect pheromone sitophilure.
reactivity of achiral and enantiomerically pure acylketene acetals are described. The key reactions of these substrates involve facile conjugate hydroboration and organolithium addition. Enantiomerically pure acylketene acetals were employed to generate a homochiral β-keto ketal through a highly diastereoselective lithium enolate quench. This β-keto ketal, which was also prepared through a desymmetrization
Conjugate addition reactions of enantiomerically pure acylketene acetals and ethyllithium. A pronounced salt effect.
作者:Joseph P. Konopelski
DOI:10.1016/s0040-4039(00)79469-x
日期:1991.1
The order of addition of salt-free ethyllithium/benzene solution to enantiomerically pure acylketene acetal 1 dictates the product formed in a chemospecific manner. Introduction of lithium bromide removes the distinction.