تفاعل #2653

معادلة التفاعل

acetic anhydride

ethyl acetate hexane

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

diethyl ether

→

title compound

المردود 98.0%

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

المردود 98.0%

المذيبات

pyridine

ظروف التفاعل

المعالجة

1. 1
   أخرىthe reaction overnight
2. 2
   workup.ADDITIONDilute
3. 3
   غسيلwash with 3M hydrochloric acid (3×100 mL), saturated sodium bicarbonate (100 mL), brine (100 mL)
4. 4
   تجفيفdry over anhydrous magnesium sulfate
5. 5
   ترشيحfilter
6. 6
   تركيزconcentrate under vacuum

الإجراء التجريبي

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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