Reacción #8866

Ecuación de reacción

triethylamine

tert-butyl 4-(1-hydroxyeth-1-yl)-4-(2-(tert-butyldimethylsilyloxy)eth-1-yl)piperidine-1-carboxylate

oxalyl chloride

DMSO

→

title product

Rendimiento 68.6%

tert-Butyl 4-acetyl-4-(2-(tert-butyldimethylsilyloxy)eth-1-yl)piperidine-1-carboxylate

Rendimiento 68.6%

Disolventes

water

methylene chloride

methylene chloride

Condiciones de reacción

Tratamiento posterior

1. 1
   workup.WAITAfter 1 h
2. 2
   Extracciónextracted three times with methylene chloride
3. 3
   LavadoThe combined organic layers were washed with brine
4. 4
   Secadodried over sodium sulfate
5. 5
   Filtraciónfiltered
6. 6
   Concentraciónconcentrated
7. 7
   OtroThe residue was purified by flash chromatography (10% ethyl acetate in hexanes)

Procedimiento

To a solution of oxalyl chloride (3.0 mL, 34 mmol) in methylene chloride (400 mL) at −70° C. was added DMSO (4.8 mL, 68 mmol) over 5 min. After 15 min, a solution of tert-butyl 4-(1-hydroxyeth-1-yl)-4-(2-(tert-butyldimethylsilyloxy)eth-1-yl)piperidine-1-carboxylate (6.6 g, 17 mmol) in methylene chloride (125 mL) was slowly added over 15 min. After 1 h, triethylamine (19 mL, 136 mmol) was added and the reaction was allowed to warm to room temperature for 1 h. The mixture was poured into water and extracted three times with methylene chloride. The combined organic layers were washed with brine, dried over sodium sulfate, filtered, and concentrated. The residue was purified by flash chromatography (10% ethyl acetate in hexanes) to afford the title product (4.5 g).

Fuente