Sodium Hydroxide → (S)-2-(1-BOC-2-pyrrolidinyl)acetic acid

関与物質

反応手順

tert-Butyl (2S)-2-(2-methoxy-2-oxoethyl)-1-pyrrolidinecarboxylate (8.35 g, 34.3 mmol) was dissolved in 150 mL MeOH. Aqueous NaOH (50 mL, 1 M) was added and the reaction mixture was allowed to stand overnight. After concentration in vacuo to ca. 100 mL, the solution was added to 300 mL water and extracted with ether (2×). The carboxylate solution was acidified to pH 2 with 12 N HCl and extracted with ether (2×). The aqueous layer was saturated with salt and extracted a third time with ether. The combined organic layers were washed with water, brine and dried over MgSO4. Filtration and concentration provided the title acid as a white solid (7.28 g, 31.7 mmol, 92.6%): 1H NMR (300 MHz, CDCl3, mixture of rotamers) δ 4.16 (bs, 1H), 3.37 (bs, 2H), 3.0–2.8 (bs, 1H), 2.36 (dd, J=9.3, 15.3 Hz, 1H), 2.2–2.0 (m, 1H), 1.9–1.7 (m, 4H), 1.48 (s, 9H) ppm.

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