反应详情

A solution of 1,4-dioxa-spiro[4.5]decan-8-one (5.00 g, 32.0 mmol) in CH2Cl2 (100 mL) was treated with morpholine (2.79 mL, 32.0 mmol), NaBH(OAc)3 (9.50 g, 44.8 mmol), and acetic acid (1.84 mL, 32.0 mmol) at RT for 4 h. The mixture was quenched with NaOH (75 mL, 2N aq) and extracted with ether (3×150 mL). The combined organic layers were washed with water (1×100 mL) and brine (1×100 mL), dried over MgSO4, and concentrated in vacuo to about 100 mL volume. HCl (9 mL, 4N in dioxane) was added dropwise with stirring. The resulting precipitate was filtered, rinsed with ether, and air-dried to afford the title compound (6.79 g, 80%) as a white solid. 1H-NMR (CD3OD; 400 MHz): δ 4.13-4.05 (m, 2H), 3.90-3.80 (m, 2H), 3.54-3.46 (m, 2H), 3.32-3.17 (m, 3H), 2.23-2.14 (m, 2H), 1.95-1.75 (m, 4H), 1.72-1.61 (m, 2H).

1. customThe mixture was quenched with NaOH (75 mL, 2N aq)
2. extractionextracted with ether (3×150 mL)
3. washThe combined organic layers were washed with water (1×100 mL) and brine (1×100 mL)
4. dry with materialdried over MgSO4
5. concentrationconcentrated in vacuo to about 100 mL volume
6. additionHCl (9 mL, 4N in dioxane) was added dropwise
7. filtrationThe resulting precipitate was filtered
8. washrinsed with ether
9. customair-dried