Lithium hydroxide, monohydrate → 2-[(4'-Methoxy[1,1'-biphenyl]-4-yl)sulfonyl]amino-4-hydroxy-5-(benzylthio)-pentanoic Acid

To a solution of 3-[(4′-methoxy[1,1′-biphenyl]-4-yl)sulfonyl]amino-2-oxo-5-[(benzylthio)methyl]-tetrahydrofuran 17a (40 mg, 0.083 mmol) in water (3 mL) and THF (3 mL) is added slowly lithium hydroxide monohydrate (35 mg, 0.82 mmol). The reaction mixture is stirred overnight, then concentrated to dryness. The resulting mixture is diluted with water, and then the mixture is extracted twice with Et2O. The Et2O layer is discarded and the aqueous layer is neutralized carefully with 1N HCl to pH 6, then extracted three times with EtOAc. The combined EtOAc layer is washed with brine, dried over MgSO4 and concentrated to a solid which is recrystallized from EtOAc/hexane (1:4) to give the desired product as a white solid.