C(Cl)Cl.[CH:4](=[O:11])[C:5]1[CH:10]=[CH:9][CH:8]=[CH:7][CH:6]=1.[C:12]1([C:18]([O:21][Si](C)(C)C)=[CH:19][CH3:20])[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1.C([O-])(O)=O.[Na+]>C(OCC)(=O)C.O.CC(O)C>[C:12]1([C:18](=[O:21])[CH:19]([CH3:20])[CH:4]([C:5]2[CH:10]=[CH:9][CH:8]=[CH:7][CH:6]=2)[OH:11])[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1From the methylene chloride solution of the chiral lead catalyst thus prepared, the solvent was evaporated, then dissolved in H2O-i-PrOH (1:4.5, 0.50 ml). After cooling at 0° C., H2O:i-PrOH (1:4.5, 1.0 ml) solutions of benzaldehyde (0.5 mmols) and 1-phenyl-1-trimethylsiloxy-1-propene (0.75 mmols) were added consecutively. After stirring for 20 hours, ethyl acetate (15 ml) and aqueous saturated NaHCO3 solution (10 ml) were added thereto to separate the organic layer, followed by the extraction of the product with ethyl acetate (10 ml×2). The resulting organic layer was dried over anhydrous sodium sulfate, then the solvent was evaporated away under reduced pressure, and the residue was purified through thin-layer silica gel chromatography to obtain 1,3-diphenyl-3-hydroxy-2-methyl-1-propanone (89%, syn:anti=91:9, 69% ee (syn)).
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