反应详情

温度

-78 °C

To a 500 ml flask, flamed dry under N2 was added CH2Cl2 (65 mL) followed by oxalyl chloride (5.2 mL, 59.6 mmol). After cooling the reaction mixture to −78° C., dimethyl sulfoxide (8.4 mL, 118.4 mmol) was added, followed by 1-benzyl 2-methyl 4-hydroxypiperidine-1,2-dicarboxylate, 13b, (8.6 g, 29.2 mmol) in CH2Cl2 (65 mL). The reaction was allowed to stir at −78° C. for 45 min. To the mixture was added triethylamine (24.4 mL, 175.1 mmol) and the mixture was allowed to warm to room temperature. The reaction mixture was diluted with CH2Cl2 and 1N HCl. The layers were separated and the aqueous phase was re-extracted with CH2Cl2. The combined organic phases were washed with water, dried over MgSO4, filtered and evaporated to dryness. The crude was purified by silica gel chromatography (30-50% EtOAc/hexanes) to give the desired product, 13c.

1. temperatureTo a 500 ml flask, flamed
2. customdry under N2
3. additionwas added CH2Cl2 (65 mL)
4. temperatureto warm to room temperature
5. customThe layers were separated
6. extractionthe aqueous phase was re-extracted with CH2Cl2
7. washThe combined organic phases were washed with water
8. dry with materialdried over MgSO4
9. filtrationfiltered
10. customevaporated to dryness
11. customThe crude was purified by silica gel chromatography (30-50% EtOAc/hexanes)