Water → HCID 69338454, compound

Participants

Reaction Steps

(2R)-t-Butoxycarbonylamino-1-n-hexanoyloxy-2-methyl-4-(benzo[b]thiophen-6-yl)butane (24.3 g, 56.0 mmol) obtained in Example 68(b) was dissolved in a mixture of tetrahydrofuran (220 ml) and methanol (110 ml), and a 1N aqueous sodium hydroxide solution (110 ml) was added thereto in an ice bath followed by stirring for 15 minutes in the ice bath and subsequently for 2 hours at room temperature. After the reaction solution was concentrated in vacuo, water was added thereto, and the solution was extracted with dichloromethane, and then the dichloromethane layer was washed with a saturated aqueous sodium chloride solution. The dichloromethane layer was dried over anhydrous sodium sulfate, and the solvent was evaporated in vacua to give a crude product (18.8 g, 100% yield). This crude product was dissolved in dimethylformamide (380 ml), and potassium t-butoxide (9.43 g, 84.1 mmol) was added thereto in an ice bath followed by stirring for 5 minutes in the ice bath and subsequently for 1 hour at room temperature. To the reaction solution was added water, and the resulting solution was extracted with ethyl acetate, and then the ethyl acetate layer was washed with a saturated aqueous sodium chloride solution. After the ethyl acetate layer was dried over anhydrous sodium sulfate, the solvent was evaporated under reduced pressure. The residue was purified by chromatography on a silica gel column (elution solvent; hexane:ethyl acetate=3:2-2:1) to afford the title compound (13.8 g, 94% yield) as a white solid.

Provenance & Evidence