To a solution of racemic (2′R,3R,4′S)-2′-[2-(2-acetoxy-ethoxy)-5-methyl-phenyl]-6-chloro-4′-(3-chlorophenyl)spiro[3H-indole-3,3′-piperidine]-2,6′(1H)-dione (0.16 g, 0.29 mmol) prepared in example 128c in tetrahydrofuran (30 mL) and methanol (10 mL) was added sodium hydroxide aqueous solution (1N, 10 mL). the reaction mixture was stirred at room temperature for 3 h, then neutralized to “pH” 7 by aqueous HCl. The mixture was then extracted with ethyl acetate. The organic layer was separated, concentrated, and purified by chromatography (EtOAc:MeOH=19:1) to give racemic (2′R,3R,4′S)-6-chloro-4′-(3-chlorophenyl)-2′-[2-(2-hydroxy-ethoxy)-5-methyl-phenyl]spiro[3H-indole-3,3′-piperidine]-2,6′(1H)-dione as a white solid (70 mg, 47%)
