反应 #2655

反应方程式

bicarbonate

p-toluenesulfonic acid

(-)-acetic acid cis-4-(tetrahydro-pyran-2-yloxy)-cyclopent-2-enyl ester

carbonate

→

title compound

收率 75.0%

(-)-cis-4-acetoxy-cyclopent-2-enol

收率 75.0%

溶剂

chloroform

ethanol

反应条件

后处理

1. 1
   其他the reaction at room temperature for 2 hours
2. 2
   浓缩concentrate under vacuum
3. 3
   其他Purify the residue by chromatography (silica gel, 3 g, 1.5×3 cm column, 33% ethyl acetate/hexane, 80 mL)

实验过程

Dissolve (-)-acetic acid cis-4-(tetrahydro-pyran-2-yloxy)-cyclopent-2-enyl ester (192 mg, 0.85 mmol, prepared in example 11) in ethanol (1.5 mL) and treat with p-toluenesulfonic acid (11.7 mg). Stir the reaction at room temperature for 2 hours. Add carbonate or bicarbonate to neutralize the reaction mixture and concentrate under vacuum. Purify the residue by chromatography (silica gel, 3 g, 1.5×3 cm column, 33% ethyl acetate/hexane, 80 mL), to provide the title compound (90 mg, 75% yield, 91% ee), [α]20 D =-66.1°, (c=0.63, chloroform).

来源