Réaction #95301

Équation de réaction

sodium borohydride

iodine

boron trifluoride

3-triphenylmethoxy-1-octyne

2-methyl-2-butene

→

title compound

1-iodo-3-triphenylmethoxy-trans-1-octene

Solvants

tetrahydrofuran

diglyme

Conditions de réaction

Traitement

1. 1
   workup.ADDITIONTo a mixture of 0.650 g
2. 2
   workup.ADDITIONis added over 15 minutes 3.24 g
3. 3
   workup.ADDITIONTo this mixture is then added over 5 minutes 8.32 g
4. 4
   Autreof diglyme, the cooling bath is removed
5. 5
   workup.ADDITIONof finely divided anhydrous trimethylamine oxide is added over 10 minutes
6. 6
   AutreThe cooling bath is removed
7. 7
   workup.STIRRINGthe mixture is stirred at ambient temperatures for 0.5 hour
8. 8
   workup.ADDITIONThe mixture is then poured into 200 ml
9. 9
   workup.STIRRINGthe resulting mixture is stirred for 0.5 hour
10. 10
    AutreThe organic phase is separated
11. 11
    Lavagethe aqueous phase is washed with ether
12. 12
    Lavagewashed with saturated brine
13. 13
    Séchagedried (Na2SO4)
14. 14
    Autreevaporated
15. 15
    AutreThe residue is dry-columned chromatographed upon alumina

Mode opératoire

To a mixture of 0.650 g. (16.91 mole) of sodium borohydride and 3.17 g. (45.2 moles) of 2-methyl-2-butene in 40 ml. of diglyme cooled to -5° C. under an inert atmospere is added over 15 minutes 3.24 g. (22.6 moles) of boron trifluoride ethereate and the resulting mixture is stirred at 0° C. for 2 hours. To this mixture is then added over 5 minutes 8.32 g. (22.6 moles) of 3-triphenylmethoxy-1-octyne (Example 119) in 10 ml. of diglyme, the cooling bath is removed, and the mixture is stirred at ambient temperatures for 1.5 hours. The mixture is cooled to 0° C. and 6.0 g. of finely divided anhydrous trimethylamine oxide is added over 10 minutes. The cooling bath is removed and the mixture is stirred at ambient temperatures for 0.5 hour. The mixture is then poured into 200 ml. of 15% sodium hydrooxide solution, a solution of 16 g. (63 moles) of iodine in 20 ml. of tetrahydrofuran is added immediately, and the resulting mixture is stirred for 0.5 hour. The organic phase is separated and the aqueous phase is washed with ether. The combined organic phase and washings are decolorized with 5% sodium thiosulfate solution, washed with saturated brine, dried (Na2SO4), and evaporated. The residue is dry-columned chromatographed upon alumina using hexane as eluent and the title compound is isolated as an oil.

Source