反应详情

To a round bottomed flask was charged 4-(2,4-bis{[tert-butyl(dimethyl)silyl]oxy}phenyl) cyclohexanone (3.20 g), 1,2-dichloroethane (85 ml), and to the stirred solution was added benzylamine (0.97 ml) as a solution in 1,2-dichloroethane (20 ml) followed by activated powdered 4 Å molecular sieves (5.80 g) and the reaction mixture stirred for 2.5 hr. Tetramethylammoniumtriacetoxyborohydride (2.90 g) was added in one portion and the reaction mixture stirred for 64 hr at room temperature. Aqueous sodium hydroxide solution (30 ml, 0.4M) was added and vigorous stirring was continued for 0.5 hr. The reaction mixture was filtered through celite, washing with dichloromethane (100 ml). The layers were separated and the aqueous layer was extracted with dichloromethane (2×50 ml). The combined organic phases were washed with brine (100 ml), dried over magnesium sulfate, filtered and concentrated in vacuo affording the-crude product. Purification via flash column chromatography (SiO2, ethyl acetate/petroleum ether, gradient elution using 1:9, 1:4, then 3:7 v/v) furnished the title compound (2.69 g, 70%) as a pale yellow oil. δH(CDCl3) 0.01 (6H, s), 0.05 (6H, s), 0.77 (9H, s), 0.83 (9H, s), 1.31 (1H, br), 1.39 (4H, m), 1.52 (2H, m), 1.70 (2H, m), 2.69 (1H, m), 2.75 (1H, m), 6.10 (1H, d), 6.23 (1H, dd), 6.84 (1H, d), 7.15 (5H, m).

1. stirringthe reaction mixture stirred for 64 hr at room temperature
2. stirringvigorous stirring
3. waitwas continued for 0.5 hr
4. filtrationThe reaction mixture was filtered through celite
5. washwashing with dichloromethane (100 ml)
6. customThe layers were separated
7. extractionthe aqueous layer was extracted with dichloromethane (2×50 ml)
8. washThe combined organic phases were washed with brine (100 ml)
9. dry with materialdried over magnesium sulfate
10. filtrationfiltered
11. concentrationconcentrated in vacuo
12. customaffording the-crude product
13. customPurification via flash column chromatography (
14. washSiO2, ethyl acetate/petroleum ether, gradient elution