Water → HCID 131736392, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of (1S,2S,3S,4R,5S)-2,3,4-tribenzyloxy-5-[4-chloro-3-[(4-ethoxy-2,3-difluoro-phenyl) methyl]phenyl]-6,8-dioxabicyclo[3.2.1]octane-1-carboxylic acid 24a (507 mg, 0.67 mmol) in methanol (10 mL) was added concentrated sulphuric acid (0.04 mL, 0.74 mmol) at room temperature. The mixture was warmed up to 40° C. and stirred for 7 hours. The reaction mixture was cooled to room temperature and adjusted with saturated aqueous sodium bicarbonate to pH 7. To the mixture was added 10 mL of water and the resulting mixture was extracted with ethyl acetate (15 mL×3). The combined organic layers were dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated in vacuo and the residue was purified by silica gel chromatography eluted with PE/EtOAc(v/v)=15/1 to give the title compound 24b as colorless oil (320 mg, 62%). The compound was characterized by the following spectroscopic data: 1H NMR (400 MHz, CDCl3) δ(ppm): 7.39 (m, 10H), 7.20 (m, 6H), 6.89 (d, 2H), 6.63 (t, 1H), 6.51 (t, 1H), 4.83 (m, 3H), 4.63 (d, 1H), 4.53 (d, 1H), 4.30 (d, 1H), 4.20 (d, 2H), 4.08-3.97 (m, 5H), 3.90 (d, 1H), 3.75 (m, 1H), 3.71 (s, 3H), 1.44 (t, 3H).

Provenance & Evidence