反应详情

温度

0 °C

To a solution of 5-methoxy-4,4-dimethyl-5-oxopentanoic acid from Step B (7.00 g, 40.2 mmol), in CH2Cl2, was added DMF (0.1 mL), followed by the slow addition of oxalyl chloride (5.00 g, 39.4 mmol) over 30 min, during which time the reaction flask was maintained under a constant stream of dry nitrogen. Stirring was continued under a light stream of dry nitrogen for an additional hour, during which time the rate of carbon dioxide evolution diminished. This freshly formed acid chloride was then transferred via canula into a 500 mL round bottom flask, cooled to 0° C., which contained N-methoxymethanamine hydrochloride (5.76 g, 59.1 mmol) and triethylamine (15.9 g, 158 mmol). The ice bath was removed after 15 min and the reaction was allowed to warm to ambient temperature. After 1 h at ambient temperature, diethyl ether (100 mL) was added to precipitate some of the triethylamine hydrochloride, which was filtered and washed with more diethyl ether. The combined organics were then washed with 1 N HCl (2×100 mL), 1 N NaOH (100 mL), water (100 mL), half-saturated brine (100 mL) and saturated brine (100 mL). The organic layer was dried over sodium sulfate, filtered and concentrated in vacuo to provide the title compound which was used without further purification. MS: m/z=218 (M+1).

1. temperaturewas maintained under a constant stream of dry nitrogen
2. waitwas continued under a light stream of dry nitrogen for an additional hour, during which time
3. customThe ice bath was removed after 15 min
4. temperatureto warm to ambient temperature
5. additiondiethyl ether (100 mL) was added
6. customto precipitate some of the triethylamine hydrochloride, which
7. filtrationwas filtered
8. washwashed with more diethyl ether
9. washThe combined organics were then washed with 1 N HCl (2×100 mL), 1 N NaOH (100 mL), water (100 mL), half-saturated brine (100 mL) and saturated brine (100 mL)
10. dry with materialThe organic layer was dried over sodium sulfate
11. filtrationfiltered
12. concentrationconcentrated in vacuo