Реакция #2660

Уравнение реакции

4-trityloxy-2-cyclopentenone

lithium aluminum hydride

lithium iodide

tert-butyl methyl ether

→

title compound

Выход 95.0%

(+/-)-cis-4-trityloxy-2-cyclopentenol

Выход 95.0%

Растворители

toluene

Условия реакции

Обработка

1. 1
   Температураwarmed to 0° C. over 30 minutes
2. 2
   workup.STIRRINGstirred at 0° C. to 15° C. for 4 hours
3. 3
   ДругоеThe reaction is quenched by slow addition of 1N NaOH (2 mL)
4. 4
   Фильтрацияthe reaction is filtered
5. 5
   ПромывкаThe solids are washed with tert-butyl methyl ether
6. 6
   Другоеthe phases of the filtrate are separated
7. 7
   СушкаThe organic phase is dried over anhydrous magnesium sulfate
8. 8
   Фильтрацияfiltered
9. 9
   Концентрированиеconcentrated under vacuum
10. 10
    ДругоеThe residue is purified by column chromatography (silica gel, 20% ethyl acetate/hexane)

Методика

A slurry of 4-trityloxy-2-cyclopentenone (1.03 g, 3.03 mmol, prepared in example 27) in toluene (8 mL) is cooled to -20° C. and treated sequentially with lithium aluminum hydride (76 mg, 2.0 mL), lithium iodide (1.06 g, 7.9 mmol) and dropwise with tert-butyl methyl ether (2 mL, over 5 minutes). The reaction is stirred for 1 hour at -20° C., warmed to 0° C. over 30 minutes, and stirred at 0° C. to 15° C. for 4 hours. The reaction is quenched by slow addition of 1N NaOH (2 mL) and then the reaction is filtered. The solids are washed with tert-butyl methyl ether and the phases of the filtrate are separated. The organic phase is dried over anhydrous magnesium sulfate, filtered and concentrated under vacuum. The residue is purified by column chromatography (silica gel, 20% ethyl acetate/hexane) to provide the title compound as a white foam (980 mg, 95%). 1H NMR (CDCl3) δ7.5 (m, 6H), 7.3 (m, 9H), 5.79 (d, 1H), 5.14 (d, 1H), 4.5 (m, 1H), 4.4 (m, 1H), 2.2 (m, 1H), 1.42 (d, 1H); 13C NMR (CDCl3) δ145.1, 136.2, 135.9, 129.0, 128.1, 127.3, 87.7, 77.4, 74.9, 43.2; IR (KBr) νmax 3422, 3057, 1491, 1364, 1084, 1065, 1024 cm-1.

Источник