反応 #1861

反応方程式

hydrochloric acid sodium chloride

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

carboethoxymethyl dimethylsulfonium bromide

2-cyclopenten-1-one

→

title compound

収率 68.3%

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

収率 68.3%

溶媒

toluene

反応条件

後処理

1. 1
   workup.WAITAfter an additional 18 hours
2. 2
   抽出The resulting mixture was extracted with diethyl ether
3. 3
   乾燥The combined ether extracts were dried over magnesium sulfate
4. 4
   ろ過filtered
5. 5
   濃縮concentrated in vacuo
6. 6
   その他The residue was purified
7. 7
   洗浄eluting with a linear gradient of 10% ethyl acetate/hexanes to 50% ethyl acetate/hexanes

実験手順

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.

出典