反应详情

To a solution of (3S, 2RS) 3-allyloxycarbonylamino-2-benzyloxy-5-oxotetrahydrofuran [Bioorg. & Med. Chem. Lett., 2, pp. 615-618 (1992)] (4.4 g, 15.1 mmol) in dichloromethane was added N,N-dimethylbarbituric acid (5.9 g, 3.8 mmol) then tetrakispalladium(0) triphenyl phosphine (1.7 g, 1.5 mmol) and the resulting mixture was allowed to stir at ambient temperature for 15 minutes. To the resulting mixture was added the acid, compound XIII (from step C) (5.0 g, 12.6 mmol), hydroxybenzotriazole(2.0 g, 14.8 mmol), then 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (2.7 g, 14 mmol) and the reaction was allowed to stir for 3 hours at ambient temperature. The reaction mixture was then poured into water and extracted with ethyl acetate. The organics were washed with 0.5M sodium bisulfate, water, sodium bicarbonate, brine, dried over magnesium sulfate and concentrated in vacuo to afford 2.6 g of the crude product as a yellow foam. The crude material was purified by column chromatography (SiO2, dichloromethane:acetone 9:1-3:1) to afford 1.2 g of the compound 4-b.

1. stirringto stir for 3 hours at ambient temperature
2. extractionextracted with ethyl acetate
3. washThe organics were washed with 0.5M sodium bisulfate, water, sodium bicarbonate, brine
4. dry with materialdried over magnesium sulfate
5. concentrationconcentrated in vacuo
6. customto afford 2.6 g of the crude product as a yellow foam
7. customThe crude material was purified by column chromatography (SiO2, dichloromethane:acetone 9:1-3:1)