反応 #2653

反応方程式

acetic anhydride

ethyl acetate hexane

(-)-cis-4-tert-butyldimethylsilyloxy-2-cyclopentenol

diethyl ether

→

title compound

収率 98.0%

(+)-acetic acid cis-4-tert-butyldimethylsilyloxy-cyclopent-2-enyl ester

収率 98.0%

溶媒

pyridine

反応条件

後処理

1. 1
   その他the reaction overnight
2. 2
   workup.ADDITIONDilute
3. 3
   洗浄wash with 3M hydrochloric acid (3×100 mL), saturated sodium bicarbonate (100 mL), brine (100 mL)
4. 4
   乾燥dry over anhydrous magnesium sulfate
5. 5
   ろ過filter
6. 6
   濃縮concentrate under vacuum

実験手順

Dissolve (-)-cis-4-tert-butyldimethylsilyloxy-2-cyclopentenol (1 g, 4.67 mmol, prepared in example 10) in pyridine (20 mL) and treat with acetic anhydride (2 mL). Stir the reaction overnight. Dilute the reaction with diethyl ether (100 mL), wash with 3M hydrochloric acid (3×100 mL), saturated sodium bicarbonate (100 mL), brine (100 mL), dry over anhydrous magnesium sulfate, filter and concentrate under vacuum to provide the title compound (1 g, 98% yield) Rf =0.5 (5% ethyl acetate/hexane) [α]20D =+1.3°, (c=1.00, chloroform), 1H NMR (CDCl3)δ5.9 (m, 1H), 5.5 (m, 1H), 4.7 (m, 1H), 2.8 (m, 1H), 2.05 (s, 3H), 1.6 (m, 1H), 0.91 (s, 9H), 0.09 (s, 6H); 13C NMR (CDCl3) δ170.8, 138.8, 131.1, 76.9, 74.8, 41.1, 25.8, 21.1, 18.1, -4.7, -4.6; IR (neat) νmax 2955, 2932, 2859, 1739, 1369, 1240, 1105, 1062, 1049 cm-1 ; CIMS m/e (% relative intensity) 256 (M+H+, 7), 197 (M+H+ --AcOH, 100).

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