Sodium Hydroxide → (S)-1'-(tert-butyl)-3-chloro-5,7-dihydrospiro[cyclopenta[b]pyridine-6,3'-pyrrolo[2,3-b]pyridin]-2'(1'H)-one

A solution of 57 (2.39 g, 6.56 mmol) in toluene (50 mL) was cooled to −2.5° C. under nitrogen atmosphere. Compound 61 (17 mg, 0.020 mmol) was charged, and the resulting solution was aged for about 15 min while cooled to −3.3° C. A pre-cooled (−1° C.). aqueous NaOH (26.2 mL, 0.3 N) was charged in over 4 min below −0.6° C. The reaction was aged at −1.3° C. for 3 h. The reaction was quenched with water (10 ml). The organic layer was washed with water (10 mL), concentrated, flushed with IPA to give crude product 58 (2.59 g, 94.4% ee, 83% wt by NMR against 1,3,5-trimethoxybenzene as an internal standard).