Reaktion #8866

Reaktionsgleichung

triethylamine

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

oxalyl chloride

DMSO

→

title product

Ausbeute 68.6%

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

Ausbeute 68.6%

Lösungsmittel

water

methylene chloride

methylene chloride

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.WAITAfter 1 h
2. 2
   Extraktionextracted three times with methylene chloride
3. 3
   WaschenThe combined organic layers were washed with brine
4. 4
   Trocknendried over sodium sulfate
5. 5
   Filtrationfiltered
6. 6
   Einengenconcentrated
7. 7
   SonstigeThe residue was purified by flash chromatography (10% ethyl acetate in hexanes)

Vorschrift

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).

Quelle