反应详情

To a solution of 3.27 g (7 mmol) of methyl 8-(p-chlorophenylsulfonamido)-4-[3-(3-pyridyl)propyl]-oct-2-enoate (example 3) in 32 ml methanol, 0.446 g (1.87 mmol) cobalt (II) chloride hexahydrate is added. The solution is cooled in an ice bath and 0.573 g (15 mmol) sodium borohydride is added in small portions. Vigorous gas evolution and formation of a black precipitate is observed during the addition of sodium borohydride. After completion of the addition, the ice bath is removed and the mixture stirred at room temperature for 1 h. The black precipitate is filtered off and washed with methanol. The combined filtrate is evaporated and the residue suspended in a mixture of 30 ml methylene chloride and 150 ml ether. The organic layer is washed with water. The aqueous phase is extracted with ether (2×50 ml). The combined organic extract is dried (MgSO4), filtered and the solvent evaporated. The residue is subjected to flash chromatography on silica using 3:2 ethyl acetate/hexane as the eluent to give methyl 8-(p-chlorophenylsulfonamido)-4-[3-(3-pyridyl)propyl]-octanoate, m.p. 81°-82°.

1. temperatureThe solution is cooled in an ice bath
2. additionAfter completion of the addition
3. customthe ice bath is removed
4. filtrationThe black precipitate is filtered off
5. washwashed with methanol
6. customThe combined filtrate is evaporated
7. additionthe residue suspended in a mixture of 30 ml methylene chloride and 150 ml ether
8. washThe organic layer is washed with water
9. extractionThe aqueous phase is extracted with ether (2×50 ml)
10. extractionThe combined organic extract
11. dry with materialis dried (MgSO4)
12. filtrationfiltered
13. customthe solvent evaporated