Reaktion #1861

Reaktionsgleichung

hydrochloric acid sodium chloride

1,8-diazabicyclo[5.4.0]undec-7-ene

carboethoxymethyl dimethylsulfonium bromide

2-cyclopenten-1-one

→

title compound

Ausbeute 68.3%

(1SR,5RS,6SR) Ethyl 2-Oxobicyclo[3.1.0]hexane-6-carboxylate

Ausbeute 68.3%

Lösungsmittel

toluene

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.WAITAfter an additional 18 hours
2. 2
   ExtraktionThe resulting mixture was extracted with diethyl ether
3. 3
   TrocknenThe combined ether extracts were dried over magnesium sulfate
4. 4
   Filtrationfiltered
5. 5
   Einengenconcentrated in vacuo
6. 6
   SonstigeThe residue was purified
7. 7
   Wascheneluting with a linear gradient of 10% ethyl acetate/hexanes to 50% ethyl acetate/hexanes

Vorschrift

A suspension of carboethoxymethyl dimethylsulfonium bromide (45.5 g) in toluene (350 mL) was treated with 1,8-diazabicyclo[5.4.0]undec-7-ene (30.2 g). The resulting mixture was stirred at room temperature. After one hour, the reaction mixture was treated with 2-cyclopenten-1-one (19.57 g). After an additional 18 hours, the reaction mixture was added to a 1N hydrochloric acid/sodium chloride solution. The resulting mixture was extracted with diethyl ether. The combined ether extracts were dried over magnesium sulfate, filtered, and concentrated in vacuo. The residue was purified using silica-gel chromatography, eluting with a linear gradient of 10% ethyl acetate/hexanes to 50% ethyl acetate/hexanes, to give 22.81 g of the title compound. Melting point: 36°-38° C.

Quelle