反应详情

To a solution of the product of step G (710 mg, 2.3 mmol) in methanol (20 mL) was added p-toluenesulfonic acid monohydrate (20 mg, 0.1 mmol). After stirring at ambient temperature for 4 h the solution was concentrated in vacuo to afford the crude product. Purification by flash column chromatography (SiO2, 19:1 to 7:3, hexanes/ethyl acetate) afforded tert-butyl 2-(acetoxymethyl)-4-hydroxypiperidine-1-carboxylate (506 mg, 83%) as a colorless oil: 1H NMR (CDCl3, 300 MHz) δ 4.49-4.41 (m, 2H), 4.33-4.05 (m, 3H), 3.94-3.88 (m, 1H), 3.29-3.21 (s, 1H), 2.05 (s, 3H), 1.89-1.80 (m, 1H), 1.76-1.69 (m, 2H), 1.46 (s, 9H).

1. concentrationwas concentrated in vacuo
2. customto afford the crude product
3. customPurification by flash column chromatography (SiO2, 19:1 to 7:3, hexanes/ethyl acetate)