反应详情

A solution of 1.365 g of methyl 2-deoxy-3-n-hexadecyl-5-trityl-D-ribofuranoside in 11.1 ml of methylene dichloride were placed in a 50 ml round-bottomed flask. 11.1 ml of MeOH were added with stirring at room temperature followed by 42.7 mg of p-toluene sulfonic acid monohydrate. After 4 hours, TLC (SiO2 ; 3:1 cyclohexane/ether or 5:1 cyclohexane/ethyl acetate) indicated reaction was substantially complete. The reaction mixture was then diluted with methylene dichloride, and the organic solution extracted with an equal volume of 0.1N aqueous sodium hydroxide (pH=12.1). The sodium hydroxide extract was washed with methylene dichloride. The methylene dichloride extracts were combined, washed with brine and dried. Evaporation of the solvent yields a solid residue which was purified by chromatography over SiO2. The solid residue was loaded onto the SiO2 column as a chloroform solution, and the column was eluted with a cyclohexane containing increasing amounts of ethyl acetate (0-20%). Two major fractions were obtained. The faster moving (first to be eluted) fraction was β-methyl 2-deoxy-3-n-hexadecyl-D-ribofuranoside (349.6 mg) and the slower moving (last to be eluted) fraction was α-methyl 2-deoxy-3-n-hexadecyl-D-ribofuranoside.

1. customreaction
2. extractionthe organic solution extracted with an equal volume of 0.1N aqueous sodium hydroxide (pH=12.1)
3. extractionThe sodium hydroxide extract
4. washwas washed with methylene dichloride
5. washwashed with brine
6. customdried
7. customEvaporation of the solvent
8. customyields a solid residue which
9. customwas purified by chromatography over SiO2
10. washthe column was eluted with a cyclohexane containing
11. temperatureincreasing amounts of ethyl acetate (0-20%)
12. customTwo major fractions were obtained
13. washto be eluted) fraction
14. wash(last to be eluted) fraction