ASYMMETRIC DEPROTONATION OF PROCHIRAL KETONES USING CHIRAL LITHIUM AMIDE BASES

Article abstract of DOI:10.1016/S0040-4020(01)85435-1

A number of chiral secondary amines have been prepared and used as precursors to the corresponding chiral lithium amide bases.Treatment of either cis-2,6-dimethylcyclohexanone or 4-tert-butylcyclohexanone with a chiral lithium amide, followed by electrophilic quench, gives chiral products in up to 88 percent enantiomeric excess.The results with 4-tert-butylcyclohexanone are in disagreement with an earlier literature report, giving products of lower enantiomeric excess but higher optical rotation.