تفاعل #2644

معادلة التفاعل

sodium hydroxide

lithium aluminum hydride

lithium iodide

4-tert-butoxy-cyclopent-2-enone

→

title compound

المردود 42.0%

cis-4-tert-butyloxy-cyclopent-2-enol

المردود 42.0%

المذيبات

toluene

tert-butyl methyl ether

ظروف التفاعل

المعالجة

1. 1
   workup.STIRRINGis stirred for 30 minutes
2. 2
   ترشيحtert-butyl methyl ether (10 mL) and filtered
3. 3
   أخرىThe phases of the filtrate are separated
4. 4
   استخلاصthe aqueous phase is extracted with tert-butyl methyl ether (15 mL)
5. 5
   تجفيفdried over magnesium sulfate
6. 6
   ترشيحfiltered
7. 7
   تركيزconcentrated under vacuum
8. 8
   أخرىThe residue is purified by chromatography (silica gel, 30 g, 33% ethyl acetate/hexane)

الإجراء التجريبي

A slurry of lithium aluminum hydride (55 mg, 1.44 mmol), lithium iodide (1.65 g, 5.76 mmol), tert-butyl methyl ether (2 mL) and toluene (3 mL) is cooled to -15° C. The slurry is treated dropwise with 4-tert-butoxy-cyclopent-2-enone(430 mg, 2.79 mmol, dissolved in 1 mL of toluene) over 5 minutes. The reaction mixture is stirred at -20° C. to -12° C. for 2 hours and then allowed to warm to room temperature and is stirred for 30 minutes. The reaction mixture is then treated sequentially with sodium hydroxide (1N, 1 mL), then tert-butyl methyl ether (10 mL) and filtered. The phases of the filtrate are separated and the aqueous phase is extracted with tert-butyl methyl ether (15 mL). The organic extracts and organic phase is combined, dried over magnesium sulfate, filtered and concentrated under vacuum. The residue is purified by chromatography (silica gel, 30 g, 33% ethyl acetate/hexane) to provide the title compound (183 mg, 42%) as a yellow oil, cis/trans/1-2+1-4 addition, 87/9.8/3.2; 1H NMR (CDCl3) 6 5.9 (m, 1H), 5.8 (m, 1H), 4.6 (m, 1H), 4.5 (m, 1H), 2.7 (m, 1H), 2.0 (d,1H, J=9.6 Hz), 1.5 (d appt, 1H, J=4.5, 14 Hz), 1.2 (s, 9H); 13C NMR (CDCl3) δ136.6, 36, 75.5, 74.4, 74, 44.6, 28.7; νmax 3395, 2974, 2938, 907, 2878, 1389, 1364, 1117, 1169, 1022 cm-1 ; MS (CI) m/e (% relative intensity) 157 (M+H+ -H2O), 57, 83 (100).

المصدر