反应详情

To a solution of (4S)-2-(4-methoxycarbonyl-2-methylphenylimino)-3,4-diisobutyl-1,3-thiazolidine (prepared in a manner analogous to that described in Method D2a; 0.035 g, 0.097 mmol) in a mixture of MeOH (1.5 mL) and H2O (1.5 mL) was added LiOH (0.016 g, 0.39 mmol). The resulting mixture was stirred for 2 d at room temp., then was concentrated under reduced pressure. The residue was adjusted to pH 1 with a 1% HCl solution, then extracted with EtOAc (4×10 mL). The combined organic layers were sequentially washed with H2O (15 mL), a saturated NaCl solution (15 mL), and dried (Na2SO4). Concentration under reduced pressure gave (4S)-2-(4-carboxy-2-methylphenylimino)-3,4-diisobutyl-1,3-thiazolidine (0.034 g, 100%): TLC (40% EtOAc/hex) Rf 0.08. This material was used in the next step without further purification.

1. concentrationwas concentrated under reduced pressure
2. extractionextracted with EtOAc (4×10 mL)
3. washThe combined organic layers were sequentially washed with H2O (15 mL)
4. dry with materiala saturated NaCl solution (15 mL), and dried (Na2SO4)
5. concentrationConcentration under reduced pressure