Реакция #8853

Уравнение реакции

triethylamine

oxalyl chloride

dimethyl sulfoxide

tert-butyl 4-(3-hydroxy-1-oxopent-1-yl)-4-methoxypiperidine-1-carboxylate

→

title compound

Выход 56.6%

tert-Butyl 4-methoxy4-(1,3-dioxopent-1-yl)piperidine-1-carboxylate

Выход 56.6%

Растворители

dichloromethane

dichloromethane

Условия реакции

Обработка

1. 1
   Другоеat −78° C.
2. 2
   workup.WAITAfter 5 min
3. 3
   Другоеthe reaction mixture was removed from the cooling bath
4. 4
   Температураto warm to room temperature for 1.5 h
5. 5
   workup.ADDITIONpoured into water
6. 6
   Экстракцияextracted three times with dichloromethane
7. 7
   Промывкаwashed with brine
8. 8
   Сушкаdried over sodium sulfate
9. 9
   Фильтрацияfiltered
10. 10
    Концентрированиеconcentrated
11. 11
    ДругоеThe residue was purified by flash chromatography
12. 12
    Промывкаeluting with 10% ethyl acetate/hexanes

Методика

To a solution of oxalyl chloride (0.168 mL, 1.92 mmol) in dichloromethane (10 mL) at −78° C. was slowly added dimethyl sulfoxide (0.272 mL, 3.84 mmol). After 5 min, a solution of tert-butyl 4-(3-hydroxy-1-oxopent-1-yl)-4-methoxypiperidine-1-carboxylate (0.404 g, 1.28 mmol) from Step B in dichloromethane (5 mL) was added via syringe. The reaction mixture was stirred for 45 min at -78° C. and then triethylamine (1.1 mL, 7.68 mmol) was added. After 5 min, the reaction mixture was removed from the cooling bath, allowed to warm to room temperature for 1.5 h, poured into water, and extracted three times with dichloromethane. The organic layers were combined, washed with brine, dried over sodium sulfate, filtered, and concentrated. The residue was purified by flash chromatography eluting with 10% ethyl acetate/hexanes to afford the title compound (0.227 g).

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