Reaktion #95932

Reaktionsgleichung

1,5-dibromopentane

t-butyl acetate

ammonium chloride

diisopropylamine

n-butyl lithium

→

title compound

7-bromoheptanoic acid t-butyl ester

Lösungsmittel

tetrahydrofuran

tetrahydrofuran

tetrahydrofuran

hexane

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGthe mixture was stirred for 30 minutes
2. 2
   workup.STIRRINGthe mixture was stirred for 5 minutes
3. 3
   workup.ADDITIONTo it was added 17 ml of hexamethylphosphamide
4. 4
   workup.STIRRINGthe mixture was stirred at -78° C. for 1 hour and at from -40° C. to -30° C. for 30 minutes
5. 5
   Sonstigewas separated aqueous layer from organic layer
6. 6
   ExtraktionThe aqueous layer was extracted with diethyl ether
7. 7
   workup.ADDITIONthe extract was added that organic layer
8. 8
   Waschenwashed with water
9. 9
   Trocknena saturated aqueous solution of ammonium chloride, dried over magnesium sulfate
10. 10
    Einengenconcentrated under reduced pressure
11. 11
    SonstigeThe residue was purified by column chromatography on silica gel using
12. 12
    workup.ADDITIONa mixture of methylene chloride and cyclohexane (1:1) as an eluent

Vorschrift

To 6.94 ml of diisopropylamine in 100 ml of anhydrous tetrahydrofuran was added dropwise 34 ml of a 1.45 M solution of n-butyl lithium in hexane at -70° C. and the mixture was stirred for 15 minutes. To the solution was added dropwise a solution of 6.63 ml of t-butyl acetate in 30 ml of anhydrous tetrahydrofuran and the mixture was stirred for 30 minutes, and then 8 ml of 1,5-dibromopentane in 10 ml of anhydrous tetrahydrofuran were added thereto and the mixture was stirred for 5 minutes. To it was added 17 ml of hexamethylphosphamide, the mixture was stirred at -78° C. for 1 hour and at from -40° C. to -30° C. for 30 minutes. To the reaction mixture was added an aqueous solution of ammonium chloride, and was separated aqueous layer from organic layer. The aqueous layer was extracted with diethyl ether, and the extract was added that organic layer and washed with water, a saturated aqueous solution of ammonium chloride, dried over magnesium sulfate and concentrated under reduced pressure. The residue was purified by column chromatography on silica gel using a mixture of methylene chloride and cyclohexane (1:1) as an eluent to give 8.5 g of the title compound having the following physical characteristic:

Quelle