Asymmetric Aldol Reactions of N-Propionyl Derivatives Of 1,3-Oxazin-2-One and Oxazolidin-2-One Chiral Auxiliaries Derived from [(1s)-Endo]-(-)-Borneol Via Lithium Enolate With Different Aldehydes

Tariq R. Sobahi

Department of Chemistry, Faculty of Science, King Abdulaziz University, Jeddah- 21589, P. O. Box 80203 (Saudi Arabia)

The work concerning this investigation involves preparation of lithium enolates of N-propionyl derivatives of 1, 3-oxazin-2-one and oxazolidin-2-one chiral auxiliaries derived from [(1S)-endo]-(-)-borneol by deprotonating N-propionyl derivatives with lithium diisopropylamide (LDA). It also involves condensation of these lithium enolates with different aldehydes in asymmetric aldol reactions. The stereochemical outcome for these aldol reactions is measured in terms of diastereomeric excess (d.e.) which is determined by analysis of the crude aldol products by high-field 1H NMR spectroscopy.

Asymmetric aldol reaction; Chiral auxiliaries; Lithium enolate