反应详情

A Solution of 1 g. of nogamycin in 20 ml. of trifluoroacetic acid is cooled in an ice bath and stirred for 5 hours. Stirring is continued while a solution of sodium methoxide in methanol is added dropwise until the reaction mixture turns purple. One hundred ml. of water is added, the pH is adjusted to 7.0 with additional sodium methoxide, and the mixture is extracted with three 100-ml. portions of methylene chloride. The combined extracts are evaporated to dryness under reduced pressure, wt. 1.004 g. A mixture of 0.5 g. of residue, 15 ml. of 0.1 M glucuronic acid, 10 ml. water, and 10 ml. of methanol is stirred for 15 minutes and filtered. The filtrate is neutralized (pH 7.0) with 1 N sodium hydroxide and stirred while maintaining at pH 7. After about 30 minutes the precipitate is collected by filtration, yield 211 mg. of con 7-0-methylnogarol. TLC in chloroform-methanol-water (78:20:2) indicates the material is homogeneous and identical with the same material prepared by methanolysis: [α]D 897° (c 0.1525, CHCl3); 13C NMR identical with that of previously prepared material; mass spectrum m/e 541.

1. stirringStirring
2. additionis added dropwise until the reaction mixture
3. extractionthe mixture is extracted with three 100-ml
4. customThe combined extracts are evaporated to dryness under reduced pressure, wt. 1.004 g
5. additionA mixture of 0.5 g
6. stirringof methanol is stirred for 15 minutes
7. filtrationfiltered
8. stirringstirred
9. temperaturewhile maintaining at pH 7
10. filtrationAfter about 30 minutes the precipitate is collected by filtration, yield 211 mg
11. customprepared by methanolysis