Control of Diastereoelectivity in Alkylation of Chiral Lithium Enolates Mediated by a Chiral Secondary Amine Ligand

Article abstract of DOI:10.1016/S0040-4039(00)91975-0

Diastereoselective alkylation of chiral lithium enolates (dl-, (R)- and (S)-9) derived from 4-t-butylcyclohexanone in the presence of a chiral secondary amine (R)-1 and lithium bromide was studied.It is shown that (R)-1 regulates the direction of the attack of electrophiles.Thus highly stereoselective axial attack was observed on (R)-9, while equatorial attack on (S)-9.The present method provides an efficient procedure for the asymmetric synthesis of 2,4-disubstituted cyclohexanones.