反应详情

At RT, 12 μl (68 μmol) of N,N-diisopropylethylamine and then 6 μl (62 μmol) of acetic anhydride were added to a solution of 38 mg (62 μmol) of the compound of Example 53A in 0.96 ml of dichloromethane, and the mixture was stirred for 1 h. The volatile components were then removed on a rotary evaporator. Since LC/MS analysis of the crude product indicated additional formation of an O-acetylated byproduct, the residue was dissolved in 2 ml of methanol and 800 μl of 2 N aqueous sodium hydroxide solution were added. After 72 h, the mixture was acidified with 1 N hydrochloric acid and separated by preparative HPLC [Method 8]. In this step, the two product diastereomers were obtained in separated form. This gave 6 mg (16% of theory) of the title compound (Diastereomer 1) and 7 mg (19% of theory) of the second diastereomer (see Example 39).

1. customThe volatile components were then removed on a rotary evaporator
2. dissolutionthe residue was dissolved in 2 ml of methanol
3. addition800 μl of 2 N aqueous sodium hydroxide solution were added
4. waitAfter 72 h
5. customseparated by preparative HPLC [Method 8]
6. customIn this step, the two product diastereomers were obtained in separated form