反应详情

A stirred solution of the product from Step II (0.427 g, 0.00288 mol) in benzene (5.2 ml) was mixed with triphenylphosphine (0.83 g, 0400317 mol) cooled in an ice bath and treated, portion-wise, during 26 minutes with N-bromosuccinimide (0.56 g, 0.00317 mol). The mixture was kept in the ice bath for 30 minutes and at ambient temperature for 3.5 hours; it was then diluted with pentane (20 ml), cooled in an ice bath for a few minutes and filtered. The solid was washed with pentane and the filtrate was concentrated. A mixture of the residue and pentane was cooled in an ice bath for a few minutes and again filtered. The filtrate was mixed with Et2O and washed successively with cold 5% aqueous sodium thiosulfate, 0.5N NaOH and brine, dried (MgSO4) and concentrated. The residue was chromatographed on silica gel with 1-3% EtOAc-hexane to give 0.440 g of 1-bromo-6-fluoro-6-methylheptane.

1. temperaturecooled in an ice bath
2. additiontreated
3. temperaturecooled in an ice bath for a few minutes
4. filtrationfiltered
5. washThe solid was washed with pentane
6. concentrationthe filtrate was concentrated
7. additionA mixture of the residue and pentane
8. temperaturewas cooled in an ice bath for a few minutes
9. filtrationagain filtered
10. additionThe filtrate was mixed with Et2O
11. washwashed successively with cold 5% aqueous sodium thiosulfate, 0.5N NaOH and brine
12. dry with materialdried (MgSO4)
13. concentrationconcentrated
14. customThe residue was chromatographed on silica gel with 1-3% EtOAc-hexane