反应详情

To a stirred solution of Intermediate 7 (2.50 g) in methanol (100 ml) under nitrogen at 0° C. was added a solution of sodium hexamethyldisilazide (1M in THF, 11.3 ml) and the resulting mixture was stirred for 10 mins, then a solution of 3-bromopropanol (1.5 g) was added. The mixture was stirred for 6 h, then evaporated and the residue treated with water (100 ml) and extracted with dichloromethane (4×50 ml). The combined dichloromethane extracts were washed with water (2×50 ml), brine (50 ml), dried over MgSO4 and evaporated. The residue was purified on silica gel eluting with 2:1 ethyl acetate/hexane, to give the title compound (2.41 g) as a colourless oil. TLC Rf0.26 (2:1 ethyl acetate/hexane).

1. stirringThe mixture was stirred for 6 h
2. customevaporated
3. additionthe residue treated with water (100 ml)
4. extractionextracted with dichloromethane (4×50 ml)
5. washThe combined dichloromethane extracts were washed with water (2×50 ml), brine (50 ml)
6. dry with materialdried over MgSO4
7. customevaporated
8. customThe residue was purified on silica gel eluting with 2:1 ethyl acetate/hexane