反应详情

A solution of Example 243A (6.8 g, 34.5 mmol) in THF (110 mL) at −78° C. under nitrogen atmosphere was treated dropwise with LDA (2.0 M solution in THF) and stirred for 1 h, then a solution of iodine in THF (30 mL) was added via cannula over about 10 min. The thick mixture was allowed to warm to rt and stirred for 1 h, then treated with saturated aqueous Na2S2O3 solution (10 mL). The mixture was concentrated to remove the THF, then H2O was added and the mixture was extracted with EtOAc. The extracts were washed with brine, dried (MgSO4) and concentrated. The residue was purified by flash chromatography on silica gel, eluting with EtOAc/hexanes (1:7), and the resulting solid was triturated with hexanes and EtOAc to give the desired product (6.8 g). Rf=0.44 (7:1 hexane:EtOAc)

1. stirringstirred for 1 h
2. concentrationThe mixture was concentrated
3. customto remove the THF
4. additionH2O was added
5. extractionthe mixture was extracted with EtOAc
6. washThe extracts were washed with brine
7. dry with materialdried (MgSO4)
8. concentrationconcentrated
9. customThe residue was purified by flash chromatography on silica gel
10. washeluting with EtOAc/hexanes (1:7)
11. customthe resulting solid was triturated with hexanes and EtOAc