(1S,2S,3S,4R,5S)-2,3,4-tribenzyloxy-5-[4-chloro-3-[[4-(2,2,2-trifluoro ethoxy)phenyl]methyl]phenyl]-6,8-dioxabicyclo[3.2.1]octane-1-carbaldehyde → 1-[(1R,2S,3S,4R,5S)-2,3,4-tribenzyloxy-5-[4-chloro-3-[[4-(2,2,2-trifluoroethoxyl)phenyl]methyl]phenyl]-6,8-dioxabicyclo[3.2.1]octan-1-yl]ethanol

Participants

Reaction Conditions

Reaction Steps

To a solution of (1S,2S,3S,4R,5S)-2,3,4-tribenzyloxy-5-[4-chloro-3-[[4-(2,2,2-trifluoroethoxyl)phenyl]methyl]phenyl]-6,8-dioxabicyclo[3.2.1]octane-1-carbaldehyde 17m (1.85 g, 2.43 mmol) in dry tetrahydrofuran (40 mL) was added dropwise methylmagnesium bromide (1.22 mL, 3.66 mmol, 3M in ethyl ether) under N2 at −10° C. The mixture was stirred at −10° C. for 15 min and then room temperature for 3 hours. The reaction mixture was quenched with saturated aqueous ammonium chloride (40 mL) and extracted with ethyl acetate (50 mL×3). The combined organic layers were washed with saturated aqueous sodium chloride (15 mL×3), 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 17n as pale yellow oil (1.3 g, 69.1%). The compound was characterized by the following spectroscopic data: 1H NMR (600 MHz, CDCl3) δ(ppm): 7.41 (d, 1H), 7.36 (m, 4H), 7.30 (m, 5H), 7.24 (m, 3H), 7.20 (d, 1H), 7.16 (t, 2H), 7.09 (d, 2H), 6.89 (d, 2H), 6.76 (d, 2H), 4.97 (m, 1H), 4.90 (d, 1H), 4.81-4.73 (m, 2H), 4.37 (d, 1H), 4.29-4.20 (m, 3H), 4.08-3.98 (m, 3H), 3.96 (d, 1H), 3.89 (d, 1H), 3.79 (m, 1H), 3.72 (t, 1H), 3.66 (m, 1H), 1.25 (d, 3H).

Provenance & Evidence