反应详情

To a round bottomed flask equipped with magnetic stirrer was loaded 4-(2,4-bis{[tert-butyl(dimethyl)silyl]oxy}phenyl)cyclohexanone (3.20 g, 7.36 mmol). Anhydrous 1,2-dichloroethane (85 ml) was added, and to the stirred solution was added benzylamine (0.97 ml, 8.83 mmol) as a solution in 1,2-dichloroethane (20 ml). Activated powdered 4 Å molecular sieves (5.80 g) were added and the reaction mixture stirred vigorously for 2.5 hr. Tetramethylammoniumtriacetoxyborohydride (2.90 g, 11.0 mmol) 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 then 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 product (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. customTo a round bottomed flask equipped with magnetic stirrer
2. additionwere added
3. stirringthe reaction mixture stirred for 64 hr at room temperature
4. stirringvigorous stirring
5. waitwas continued for 0.5 hr
6. filtrationThe reaction mixture was then filtered through celite
7. washwashing with dichloromethane (100 ml)
8. customThe layers were separated
9. extractionthe aqueous layer was extracted with dichloromethane (2×50 ml)
10. washThe combined organic phases were washed with brine (100 ml)
11. dry with materialdried over magnesium sulfate
12. filtrationfiltered
13. concentrationconcentrated in vacuo
14. customaffording the crude product
15. customPurification via flash column chromatography (
16. washSiO2, ethyl acetate/petroleum ether, gradient elution