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A new experimental protocol is described which greatly improves our recently reported method for the determination of the enantiomeric composition of alcohols, phenols, thiols, and amines. Thus, successive addition into the NMR tube of (1) a chiral fluorinated diamine (or any other chiral Cg symmetrical diamine), (2) CDCI3, (3) a tertiary amine, (4) PCI3, and 5) the chiral alcohol, phenol, thiol, or amine allows a 31P NMR spectrum of the diastereomeric derivatives to be recorded in 5 min. The method is accurate and very general, and no kinetic discrimination is observed. Sulfuration or selenation of the trivalent phosphorus derivatives, carried out in the NMR tube, allows for a second 31P NMR determination, in addition to the , 13C, and 19F NMR spectra which may also be recorded.

cussions. The financial help of Rh6ne-Poulenc Company through a grant to S.M. is also greatly appreciated. 1r(13) Typical procedure: To a suspension of CUI (476 mg; 2.5 mmol) in T H F (40 mL) is added ligand 1 (3.4 mL of a 1.5 N solution in toluene; 5.1 mmol) at -30 OC. The temperature is allowed to rise, and solubilization is usually observed around IO OC. After stirring for 15 min, the solution is cooled to -40 OC and nBuLi (1.45 mL of a 1.6 M solution in hexane; 2.3 mmol) is added. The solution, which turns yellow, is warmed for IS min at -5 OC and then cooled again to 78 OC, and 2-cyclohexenone 7 (200 & 2 mmol) in T H F ( 5 mL) is introduced. The mixture is then slowly warmed to -30 OC (in 1 h) and stirred until the disappcarance of 7. Hydrolysis was carried out with 15 mL of 5 N HCI, and stirring is continued in the open air for 1 h in order to hydrolyze the ligand completely. The aqueous phase is extracted with two 1 0 0 " portions of ether, and the combined organic phases were then washed twice with NH,OH in order to remove the copper salts. The solvents were removed in vacuo, and the crude product was treated with (R,R)-2,3-butanediol in a Dean-Stark trap.* The final ketal 9 was purified by flash column chromatography and then by Kugelrohr distillation.

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