反应详情

To a stirred solution of 8-benzyloxycarbonyl 1,4-dioxa-8-azaspiro[4,5] decane (0.037 mol, 10 g) in tetrahydrofuran (150 mL) was added a solution of hydrochloric acid 5% (20 mL) dropwise at room temperature. The solution was stirred for 18 h (TLC control) and then evaporated under vacuum to small volume (20 mL) and neutralized with a saturated sodium bicarbonate solution. The aqueous solution was extracted with ethyl acetate (3×100 mL) and the organic layers were dried over sodium sulfate and finally evaporated under vacuum to give 1-benzyloxycarbonyl piperidin-4-one which was substantially pure and which was used in the next step without any purification (92% yield). 1H-NMR (CDCl3): 1.63 (m, 4H); 3.56 (m,4H); 5.09 (s, 2H); 7.28 (s, 5H).

1. customevaporated under vacuum to small volume (20 mL)
2. extractionThe aqueous solution was extracted with ethyl acetate (3×100 mL)
3. dry with materialthe organic layers were dried over sodium sulfate
4. customfinally evaporated under vacuum