Reaktion #456969

Reaktionsgleichung

tri-o-tolyphosphine

2-iodobenzyl alcohol

toluene

cyclopentene

tri-ortho-tolylphosphine

→

2-cyclopentylbenzyl alcohol

Ausbeute 74.0%

Lösungsmittel

MeOH

EtOAc

hexane

CH2Cl2

Et3N

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeThe mixture was deoxygenated
2. 2
   Sonstigeby bubbling N2 through for 10 min
3. 3
   workup.ADDITIONwas then treated with 0.96 g of Pd(OAc)2 (Aldrich)
4. 4
   SonstigeThe bomb was flushed with N2
5. 5
   Sonstigesealed
6. 6
   TemperaturThe vessel was cooled to RT
7. 7
   Sonstigepurged with N2
8. 8
   SonstigeThe dark red reaction mixture
9. 9
   Einengenwas concentrated in vacuo
10. 10
    Sonstigeto give a red-brown syrup
11. 11
    Waschenwashed with water (4×100 mL)
12. 12
    Trocknendried over anhydrous MgSO4
13. 13
    Einengenconcentrated in vacuo
14. 14
    Sonstigeto afford a brown oil
15. 15
    SonstigeThe crude product was purified by flash chromatography (twice) on 200 g of silica gel (9:1 hexane:EtOAc)
16. 16
    Sonstigeto afford 6
17. 17
    workup.ADDITIONa mixture of double bond isomers by 1H-NMR
18. 18
    SonstigeThe catalyst was removed by filteration through celite
19. 19
    Einengenthe filtrate was concentrated in vacuo

Vorschrift

A 300 mL Parr bomb was charged with 10.0 g of 2-iodobenzyl alcohol (Aldrich), 80 mL of toluene, 30 mL of cyclopentene (Aldrich), 2.60 g of tri-ortho-tolylphosphine (Aldrich), and 6.6 mL of Et3N. The mixture was deoxygenated by bubbling N2 through for 10 min and was then treated with 0.96 g of Pd(OAc)2 (Aldrich). The bomb was flushed with N2, sealed, and heated to 100° C. for 18 h. The vessel was cooled to RT, purged with N2 and opened. The dark red reaction mixture was concentrated in vacuo to give a red-brown syrup. This material was dissolved in 200 mL of CH2Cl2, washed with water (4×100 mL), dried over anhydrous MgSO4, and concentrated in vacuo to afford a brown oil. Analysis by tlc (SiO2, 8:2 hexane:EtOAc) indicated two new major components at Rf =0.45 and 0.50, tri-o-tolyphosphine at Rf =0.90, and 4 minor components at Rf =0.60, 0.70, 0.85 and 0.0. The crude product was purified by flash chromatography (twice) on 200 g of silica gel (9:1 hexane:EtOAc) to afford 6:1 g (82%) of a mixture of the Rf =0.45 and 0.50 materials. This material was determined to be a mixture of double bond isomers by 1H-NMR. The product (6.0g ) was then hydrogenated at 40 psi in 40 mL of MeOH in the presence of 0.60 g of 5% Pt(C) (Aldrich) for 4 h. The catalyst was removed by filteration through celite and the filtrate was concentrated in vacuo to afford 5.47 g (74% from 2-iodobenzyl alcohol) of 2-cyclopentylbenzyl alcohol as a light yellow-brown liquid.

Quelle