SYNTHESIS AND CHARACTERIZATION OF ACYLATED CHIRAL OXAZOLIDINE-2-SELONES - SELONE CHIRAL DERIVATIZING AGENTS FOR THE DETECTION AND QUANTITATION OF REMOTELY DISPOSED CHIRAL CENTERS

Racemic and chiral carboxylic acids and acid chlorides are coupled cle anly to oxazolidine-2-selone chiral derivatizing agents (CDA's) with y ields ranging from 85 to 99%. Se-77 NMR spectroscopy provides a highly sensitive method for the determination of the enantiomeric excesses o f these remotely disposed chiral centers. The geometrical relationship between the selenocarbonyl and the adduct carbonyl (syn or anti) appe ars to have a profound effect on the chemical shift difference (Delta delta(Se)) observed for pairs of adduct diastereomers. Crystallographi c and solution state NMR studies suggest that the syn orbital overlap enhances the Delta delta(Se).