Reaktion #2006439

Reaktionsgleichung

hydrogen

cyclopentadiene

cyclopentadiene

bromine

hydrogen peroxide

NaOH

bromine

→

alcohol

1-Cyclopentylcyclopentanol

Lösungsmittel

tetrahydrofuran

tetrahydrofuran

tetrahydrofuran

methanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeTo a 1000-mL 3-necked round bottom flask equipped with a 250-mL pressure
2. 2
   workup.ADDITIONaddition funnel, a nitrogen inlet with thermocouple and an overhead stirrer
3. 3
   SonstigeThe flask was immersed in an ice-water bath
4. 4
   SonstigeThe solvent was then removed under reduced pressure
5. 5
   Sonstigethe remaining oil transferred to a 5 L 3-necked round bottom flask
6. 6
   Sonstigeequipped with a thermocouple inlet
7. 7
   workup.ADDITIONoverhead stirrer and a 500-mL addition funnel
8. 8
   workup.ADDITIONDichloromethane (2 L) and water (500 mL) were added
9. 9
   workup.ADDITIONwas then added slowly over 1 hr
10. 10
    Sonstigewas recooled to 5° C.
11. 11
    workup.STIRRINGAfter stirring overnight at room temperature the organic layer
12. 12
    Sonstigewas separated
13. 13
    Waschenwashed several times with water
14. 14
    Trocknenonce with brine and then dried over anhydrous magnesium sulfate for 1 hour
15. 15
    FiltrationFiltration and removal of the solvent at reduced pressure
16. 16
    Sonstigeresulted in a light-colored oil which
17. 17
    workup.DISTILLATIONwas distilled from Na2CO3 through a short Vigreux (bp 63° C.@ 1 mmHg)

Vorschrift

To a 1000-mL 3-necked round bottom flask equipped with a 250-mL pressure equalizing addition funnel, a nitrogen inlet with thermocouple and an overhead stirrer was added 172 mL (1.72 mol) of a 10M solution of BH3-Me2S in tetrahydrofuran and 300 mL of dry tetrahydrofuran. The addition funnel was charged with 116.8 g (1.72 mol) of cyclopentadiene dissolved in 100 mL of dry tetrahydrofuran. The flask was immersed in an ice-water bath and the cyclopentadiene solution slowly added over 2 hours at 0-5° C. Stirring was continued for an additional 90 min at this temperature at which time 130 mL of methanol was cautiously added over 1 hour with vigorous evolution of hydrogen. The solvent was then removed under reduced pressure and the remaining oil transferred to a 5 L 3-necked round bottom flask equipped with a thermocouple inlet, overhead stirrer and a 500-mL addition funnel. Dichloromethane (2 L) and water (500 mL) were added and the mixture cooled to 5° C. The addition funnel was charged with 100 mL (1.95 mol) of bromine which was then added slowly over 1 hr. The resulting dark mixture was exposed to a long wave UV lamp with stifling at room temperature overnight by which time the bromine color had largely disappeared. The reaction mixture was recooled to 5° C. and 1.3 L of 6N NaOH was added slowly via the addition funnel followed by 400 mL of 30% hydrogen peroxide. After stirring overnight at room temperature the organic layer was separated, washed several times with water, once with brine and then dried over anhydrous magnesium sulfate for 1 hour. Filtration and removal of the solvent at reduced pressure resulted in a light-colored oil which was distilled from Na2CO3 through a short Vigreux (bp 63° C.@ 1 mmHg) to yield 72 g (55%) the title alcohol as a clear, colorless oil.

Quelle