Reaction #362815

Reaction equation

sodium borohydride

1

(±)-2-Methyl-5-isobutyl-1-indanone

HCl

→

2

Yield 95.0%

2-Methyl-6-isobutylindene

Yield 95.0%

Solvents

tetrahydrofuran methanol

Conditions

Workup

1. 1
   Extractionthe mixture was extracted 3 times with 50 ml of diethyl ether in each case
2. 2
   DryingThe combined organic phases were dried (MgSO4)
3. 3
   Otherfreed from solvent on a rotary evaporator
4. 4
   workup.ADDITION0.4 g of p-toluenesulfonic acid was added
5. 5
   Temperaturethe mixture was refluxed for 2 hours
6. 6
   WashThe reaction mixture was washed twice with 50 ml of saturated aqueous NaHCO3 solution in each case
7. 7
   Otherfreed from solvent on a rotary evaporator
8. 8
   OtherThe residue was purified by chromatography on 400 g of silica gel (hexane)

Procedure

2.4 g (62 mmol) of sodium borohydride were added to a solution of 8.3 g (41 mmol) of 1 in 50 ml of tetrahydrofuran/methanol (2:1), and the mixture was stirred at room temperature for 16 hours. 50 ml of conc. aqueous HCl were subsequently added, and the mixture was extracted 3 times with 50 ml of diethyl ether in each case. The combined organic phases were dried (MgSO4) and freed from solvent on a rotary evaporator. The residue was taken up in 100 ml of toluene, 0.4 g of p-toluenesulfonic acid was added, and the mixture was refluxed for 2 hours. The reaction mixture was washed twice with 50 ml of saturated aqueous NaHCO3 solution in each case and freed from solvent on a rotary evaporator. The residue was purified by chromatography on 400 g of silica gel (hexane), giving 7.17 g (95%) of 2 as a colorless oil.

Source