反应详情

温度

5 °C

(Reference: Park, K. K.; Oh, C. H.; Joung, W. K. Tetrahedron Lett. 1993, 34, 7445-7446) The product from Example 60A (992 mg, 4.31 mmol) in CH2Cl2 at 23° C. (6 mL) was treated with water (1.5 mL) and N,N′-diheptyl-4,4′-bipyridinium dibromide (43 mg, 10 mg/mmol of substrate). The biphasic mixture was cooled to 5° C. and treated with a solution of sodium dithionite (3.00 g, 17.2 mmol) and K2CO3 (2.68 g, 19.4 mmol) in water (3.5 mL). The cooling bath was removed and the biphasic mixture stirred vigorously at 23° C. for 4 hours. The mixture was partitioned between additonal CH2Cl2 (15 mL) and water (10 mL) and the aqueous layer was extracted with CH2Cl2 (10 mL). The combined organic portions were washed with brine (10 mL) and dried (Na2SO4). Ethyl acetate (5 mL) was added along with silica gel (5 g) and the suspension was filtered through a small pad of Celite, rinsing with 10% ethyl acetate/CH2Cl2 (15 mL). The filtrate was concentrated to provide the title compound (716 mg, 3.58 mmol, 82%) as an off-yellow powder.

1. customThe cooling bath was removed
2. customThe mixture was partitioned between additonal CH2Cl2 (15 mL) and water (10 mL)
3. extractionthe aqueous layer was extracted with CH2Cl2 (10 mL)
4. washThe combined organic portions were washed with brine (10 mL)
5. dry with materialdried (Na2SO4)
6. additionEthyl acetate (5 mL) was added along with silica gel (5 g)
7. filtrationthe suspension was filtered through a small pad of Celite
8. washrinsing with 10% ethyl acetate/CH2Cl2 (15 mL)
9. concentrationThe filtrate was concentrated