Reaktion #8863

Reaktionsgleichung

lithium borohydride

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

lithium borohydride

→

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

Lösungsmittel

THF

THF

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeThe mixture was then quenched with acetic acid
2. 2
   workup.ADDITIONdiluted with ether and aq. sodium bicarbonate solution
3. 3
   Extraktionextracted three times with ether
4. 4
   WaschenThe combined organic layers were washed with brine
5. 5
   Trocknendried over sodium sulfate
6. 6
   Filtrationfiltered
7. 7
   Einengenconcentrated
8. 8
   SonstigeThe residue was purified by flash chromatography (20% ethyl acetate in hexanes)
9. 9
   Sonstigeto afford
10. 10
    Sonstigerecovered

Vorschrift

The crude tert-butyl 4-methoxycarbonyl-4-(2-(tert-butyldimethylsilyloxy)eth-1-yl)piperidine-1-carboxylate (assumed 44 mmol) from Step A was taken up in THF (200 mL) and 2M lithium borohydride in THF (29 mL, 58 mmol) was added via syringe at room temperature. The reaction was stirred for 2 days at room temperature and then at 50° C. for 20 h after addition of more 2M lithium borohydride in THF (2.9 mL, 5.8 mmol). The mixture was then quenched with acetic acid, diluted with ether and aq. sodium bicarbonate solution, and extracted three times with ether. The combined organic layers were washed with brine, dried over sodium sulfate, filtered, and concentrated. The residue was purified by flash chromatography (20% ethyl acetate in hexanes) to afford recovered starting material (2.5 g) and the title product (7.1 g).

Quelle