Reaktion #8849

Reaktionsgleichung

HCl

tert-Butyl 1-oxo-8-azaspiro[4.5]decane-8-carboxylate

ethyl formate

potassium t-butoxide

→

title compound

Ausbeute 51.4%

tert-Butyl 2-(hydroxymethyl)-1-oxo-8-azaspiro[4.5]decane-8-carboxylate

Ausbeute 51.4%

Lösungsmittel

diethyl ether

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigeby evaporating with toluene (10 mL) three times in vacuo
2. 2
   workup.DISSOLUTIONdissolved in methyl-tert-butyl ether (5 mL)
3. 3
   Extraktionextracted three times with diethyl ether
4. 4
   Waschenwashed with brine
5. 5
   Trocknendried over sodium sulfate
6. 6
   Filtrationfiltered
7. 7
   Einengenconcentrated
8. 8
   Sonstigeto afford 0.575 g
9. 9
   SonstigeThe residue was purified by flash chromatography
10. 10
    Wascheneluting with 45% ethyl acetate/hexanes

Vorschrift

tert-Butyl 1-oxo-8-azaspiro[4.5]decane-8-carboxylate from Procedure 1, Step G (0.526 g, 2.08 mmol) was dried by evaporating with toluene (10 mL) three times in vacuo, dissolved in methyl-tert-butyl ether (5 mL), and cooled to −78° C. To this solution was added ethyl formate (0.336 mL, 4.15 mmol) and then potassium t-butoxide (0.466 g, 4.16 mmol). After 2 days, the reaction mixture was diluted with diethyl ether, poured into 2N HCl, and extracted three times with diethyl ether. The organic layers were combined, washed with brine, dried over sodium sulfate, filtered, and concentrated to afford 0.575 g. The residue was purified by flash chromatography eluting with 45% ethyl acetate/hexanes to give the title compound (0.303 g). MS/EI (acetonitrile/water): m/z 304 (M+1+Na) retention time=2.9 min.

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