反应详情

To a stirred solution of (2S,3R,4R,5S,6R)-2-[4-Cyclopropyl-3-(2,3-dihydro-benzo[1,4]dioxin-6-ylmethyl)-phenyl]-6-hydroxymethyl-tetrahydro-pyran-3,4,5-triol (Intermediate 3, 890 mg, 2.1 mmol) in collidine (7 ml) was added a solution of methyl chloroformate (0.21 ml, 2.5 mmol) in DCM (0.5 ml) at −40° C. After stirring for 1 h at same temperature, it was stirred at room temperature for 1.5 h. Reaction mixture was poured into ice cold 10% HCl solution and extracted with ethyl acetate (2×10 ml). Combined organic layers were washed with brine (10 ml), dried over sodium sulfate, concentrated and purified by silica gel column chromatography to give 1.1 g of carbonic acid (2R,3S,4R,5R,6S)-6-[4-cyclopropyl-3-(2,3-dihydro-benzo[1,4]dioxin-6-ylmethyl)-phenyl]-3,4,5-trihydroxy-tetrahydro-pyran-2-ylmethyl ester methyl ester as a white solid.

1. stirringwas stirred at room temperature for 1.5 h
2. customReaction mixture
3. extractionextracted with ethyl acetate (2×10 ml)
4. washCombined organic layers were washed with brine (10 ml)
5. dry with materialdried over sodium sulfate
6. concentrationconcentrated
7. custompurified by silica gel column chromatography