Reaktion #8845

Reaktionsgleichung

tert-butyl 2-(methoxycarbonyl)-1-oxo-8-azaspiro[4.5]decane-8-carboxylate

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

lithium hydroxide

→

title compound

Ausbeute 67.5%

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

Ausbeute 67.5%

Lösungsmittel

ethanol tetrahydrofuran water

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONwas added
2. 2
   Temperaturto cool
3. 3
   Einengenwas then concentrated
4. 4
   workup.DISSOLUTIONdissolved in water
5. 5
   Extraktiondichloromethane, and extracted three times with dichloromethane
6. 6
   Waschenwashed with brine
7. 7
   Trocknendried over sodium sulfate
8. 8
   Filtrationfiltered
9. 9
   Einengenconcentrated
10. 10
    Sonstigeto afford 11.4 g
11. 11
    SonstigeThe residue was purified by flash chromatography
12. 12
    Wascheneluting with 20–30% ethyl acetate in hexanes

Vorschrift

To a solution of tert-butyl 2-(methoxycarbonyl)-1-oxo-8-azaspiro[4.5]decane-8-carboxylate (17.2 g, 0.055 mol) from Step F in a 2:2:1 mixture of ethanol/tetrahydrofuran/water (555 mL) was added pulverized lithium hydroxide (26 g, 1.10 mol). The reaction mixture was heated to 90° C. for 60 h. The reaction mixture was allowed to cool and was then concentrated, dissolved in water and dichloromethane, and extracted three times with dichloromethane. The organic layers were combined, washed with brine, dried over sodium sulfate, filtered, and concentrated to afford 11.4 g. The residue was purified by flash chromatography eluting with 20–30% ethyl acetate in hexanes to give the title compound (9.41 g).

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