反应详情

6,7,8-Triacetoxy-1-bromomethyl-3-oxo-2-oxa-4-azabicyclo[3.3.1]nonane (as described in Example 1 of the Japanese Patent Application No. 144309/1981, pp. 37) (800 mg) is dissolved in toluene (50 ml), and tri-n-butyltin hydride (1 ml) and α,α'-azo-bis-isobutyronitrile (100 mg) are added to the solution, followed by reflux with stirring for 1 hour. The reaction mixture is concentrated under reduced pressure, and petroleum ether is added to the residue, which is allowed to stand overnight in a refrigerator. The resulting precipitates are recovered by filtration, dried and chromatographed on a column of silica gel (180 ml), followed by elution with ethyl acetate. The eluate is concentrated under reduced pressure, and ethyl ether-petroleum ether (1:1) is added to the residue, which is allowed to stand overnight in a refrigerator to produce crystalline 6,7,8-triacetoxy-1-methyl-3-oxo-2-oxa-4-azabicyclo[3.3.1]nonane (510 mg).

1. temperatureby reflux
2. concentrationThe reaction mixture is concentrated under reduced pressure, and petroleum ether
3. additionis added to the residue, which
4. waitto stand overnight in a refrigerator
5. customThe resulting precipitates
6. filtrationare recovered by filtration
7. customdried
8. customchromatographed on a column of silica gel (180 ml)
9. washfollowed by elution with ethyl acetate
10. concentrationThe eluate is concentrated under reduced pressure, and ethyl ether-petroleum ether (1:1)
11. additionis added to the residue, which
12. waitto stand overnight in a refrigerator