反应详情

Dissolve 1,4-dioxaspiro{4.5}decan-8-one (100 g, 640.3 mmol), methyl-4-aminobutyrate hydrochloride (98.5 g, 640.3 mmol), triethylamine (90 mL, 640.3 mmol) and dichloromethane (2 L) and stir at room temperature. Add Sodium triacetoxyborohydride (135.7 g, 640.3 mmol) stir 17 h at room temperature. Quench with water (1 L), separate, wash the aqueous layer with dichloromethane (3×500 mL), combine the organic phases and dry over anhydrous sodium sulfate, filter and concentrate. Purify the material on a 1.5 kg silica column, 6 inches in diameter, and eluted with 8:2 hexanes/ethyl acetate to 95:5 ethyl acetate/methanol to give 73 g of the title compound as a waxy brown solid. 1H NMR (CDCl3) δ 3.99-4.10 (m, 1H), 3.93 (s, 4H), 3.32-3.36 (m, 2H), 2.36-2.40 (m, 2H), 1.94-2.03 (m, 2H), 1.65-1.83 (m, 8H).

1. customQuench with water (1 L)
2. customseparate
3. washwash the aqueous layer with dichloromethane (3×500 mL)
4. dry with materialdry over anhydrous sodium sulfate
5. filtrationfilter
6. concentrationconcentrate
7. customPurify the material on a 1.5 kg silica column, 6 inches in diameter
8. washeluted with 8:2 hexanes/ethyl acetate to 95:5 ethyl acetate/methanol