Реакция #710552

Уравнение реакции

triethylamine

tert-butyl 3-(tert-butyldimethyl-silyloxy)-2-hydroxypropylcarbamate

oxalyl chloride

DMSO

→

tert-butyl 3-(tert-butyldimethylsilyloxy)-2-oxopropylcarbamate

Выход 92.0%

Растворители

CH2Cl2

CH2Cl2

Условия реакции

Обработка

1. 1
   workup.ADDITIONAfter complete addition the resulting solution
2. 2
   workup.STIRRINGStirring
3. 3
   workup.ADDITIONwas added
4. 4
   ДругоеThe cooling bath was removed
5. 5
   Температураto warm to room temperature
6. 6
   ДругоеThe reaction mixture was partitioned between water (100 mL) and CH2Cl2 (70 mL)
7. 7
   Экстракцияthe aqueous layer was extracted with further CH2Cl2 (2×70 mL)
8. 8
   Сушкаthe combined organics were dried over Na2SO4
9. 9
   Концентрированиеconcentrated under a stream of nitrogen gas
10. 10
    ДругоеThe crude residue was purified over silica gel eluting with 5% ethylacetate in n-hexane

Методика

To a stirring solution of oxalyl chloride (13.6 mL, 0.16 mol) in dry CH2Cl2 (150 mL) at −78° C. under N2 was added DMSO (15.2 mL, 0.21 mol) dropwise over 30 min. After complete addition the resulting solution was stirred at −78° C. for 1 h. A solution of tert-butyl 3-(tert-butyldimethyl-silyloxy)-2-hydroxypropylcarbamate (32.6 g, 0.11 mol) in CH2Cl2 (50 mL) was then added dropwise over 20 min. Stirring was continued for a further 1 hour at which time triethylamine (59.6 mL, 0.43 mol) was added. The cooling bath was removed and the reaction mixture was allowed to warm to room temperature. The reaction mixture was partitioned between water (100 mL) and CH2Cl2 (70 mL) and the aqueous layer was extracted with further CH2Cl2 (2×70 mL); the combined organics were dried over Na2SO4 and concentrated under a stream of nitrogen gas. The crude residue was purified over silica gel eluting with 5% ethylacetate in n-hexane to give tert-butyl 3-(tert-butyldimethylsilyloxy)-2-oxopropylcarbamate (29.8 g, 92%) as a pale yellow oil. 1H-NMR (300 MHz; CDCl3) δ ppm: 0.11 (6H, s), 0.94 (9H, s), 1.47 (9H, s), 3.92 (2H, s), 4.26 (2H, d, J 4.6 Hz), 5.22 (1H, br s).

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