Reaktion #90653

Reaktionsgleichung

ethyl cyclobutanecarboxylate

acetone

→

1-cyclobutyl-1,3-butanedione

Ausbeute 76.0%

Lösungsmittel

Ether

ether

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONAfter addition
2. 2
   workup.ADDITIONpoured onto ice water
3. 3
   workup.STIRRINGwith stirring
4. 4
   Extraktionthe unreacted components were extracted into the organic phase
5. 5
   ExtraktionThe clear aqueous extract
6. 6
   ExtraktionThe solution was extracted with ether
7. 7
   TrocknenThe combined organic layers were dried (Na2SO4)
8. 8
   Filtrationfiltered
9. 9
   Einengenconcentrated

Vorschrift

To a solution of NaNH2 (11.7 g, 91 mmol) in anhydrous ether (150 mL) under N2 at 30° C. was added dropwise a mixture of ethyl cyclobutanecarboxylate (19.2 g, 150 mmol) and acetone (21.75 g, 375 mmol). After addition, the reaction mixture was stirred for 4 h, then poured onto ice water with stirring. Ether was added and the unreacted components were extracted into the organic phase. The clear aqueous extract was acidified to pH 5.0 with 2 N HCl, and then to pH 7.5 with Na2CO3. The solution was extracted with ether. The combined organic layers were dried (Na2SO4), filtered, and concentrated to give the crude product of 1-cyclobutyl-1,3-butanedione (9.7 g, 76%), which was used in the next step without further purification. 1H NMR (400 MHz, CDCl3-d3) δ 5.42 (s, 1H), 3.66 (s, 1H), 2.11-2.23 (m, 4H), 2.02 (s, 3H), 1.93-1.99 (m, 2H).

Quelle