1. CDCl 3 ) ? 4.72 (s, 1H;H Nmr (600 Mhz;Cp-H)
2. diphenylhydroxy)methylferrocene 24. The solution of (S, Sp)-23 (438 mg, 1.13 mmol);Cp-C�5)
3. 56 mmol, 2.3 equiv.) slowly by syringe. The mixture was stirred for 2 h, and then warmed to 0 o C for 8 h. The resulting solution was treated with recrystallized benzophenone (413 mg, 2.27 mmol, 2 equiv.) and kept stirring for further 6 h. The reaction was quenched with saturated NaHCO 3 solution, extracted with Et 2 O twice and dried over MgSO 4 . The crude product was purified by column chromatography (silica gel, hexane/EtOAc = 99/1);M;24 yielded as an orange solid (425 mg, 0.75 mmol; 66%),1038