تفاعل #2645
ord-4080122b276c4fa69f2e3e82eeb5a920
معادلة التفاعل
المتفاعلات
الكواشف
المذيبات
ظروف التفاعل
المعالجة
- 1ترشيحThe reaction is then filtered through diatomaceous earth
- 2تركيزthe filtrate is concentrated under vacuum
- 3أخرىThe products are separated by chromatography on silica gel (5% to 20% ethyl acetate/hexane)
الإجراء التجريبي
Cis-4-tert-butyldimethylsilyloxy-2-cyclopentenol (10.0 g, 46.6 mmol, prepared in example 3a) is dissolved in tert-butyl methyl ether (60 mL, anhydrous). To the solution is added triethylamine (4.5 mL, 32.3 mmol), pancreatin (30 g, available from Sigma Chemical Company), and vinyl acetate (22 mL, 239 mmol). The reaction is allowed to stir for 7 hours at room temperature. The reaction is then filtered through diatomaceous earth and the filtrate is concentrated under vacuum. The products are separated by chromatography on silica gel (5% to 20% ethyl acetate/hexane) to provide (-)-acetic acid 4-tert-butyldimethylsilyloxy-cyclopent-2-enyl ester (B, 6.1 g, 51% yield, 99% ee), [α]D -0.2°, (c=0.52, chloroform) as a yellow oil and (-)-cis-4-tert-butyldimethylsilyloxy-2-cyclopentenol (A, 4.7 g, 47% yield, >99% ee), [α]D -18.6°, (c=1.01, chloroform) as a yellow oil.