Reaction #1552077

Reaction equation

4-Isobutyl-1-methylcyclohex-3-enecarbaldehyde

MeMgBr

→

colorless oil

Yield 89.9%

1-(4-Isobutyl-1-methylcyclohex-3-enyl)ethanol

Yield 89.9%

Solvents

diethyl ether

Conditions

Workup

1. 1
   OtherAn ice-bath was used
2. 2
   Otherthe temperature below 20° C.
3. 3
   workup.ADDITIONwas added over 30 min
4. 4
   OtherThe ice-bath was removed
5. 5
   workup.STIRRINGthe reaction stirred for a further 30 min
6. 6
   workup.ADDITIONbefore being poured slowly
7. 7
   OtherThe phases were separated
8. 8
   Washthe upper organic phase washed twice with brine (2×100 ml)
9. 9
   Dryingdried (MgSO4)
10. 10
    Concentrationconcentrated in vacuo

Procedure

4-Isobutyl-1-methylcyclohex-3-enecarbaldehyde 3a (20 g, 111 mmol) was dissolved in diethyl ether (120 ml) and the solution stirred under nitrogen. An ice-bath was used to keep the temperature below 20° C. while MeMgBr (3M, 48 ml, 144 mmol) was added over 30 min. The ice-bath was removed and the reaction stirred for a further 30 min before being poured slowly, and under nitrogen, onto 2M HCl (50 ml). The phases were separated and the upper organic phase washed twice with brine (2×100 ml), dried (MgSO4) and concentrated in vacuo to give 19.6 g of a colorless oil. The product was purified by distillation (0.1 mbar, 90° C.) to give 4c as a 4:5 mixture of diastereomers containing 6.5% of a third isomer (14 g, 52% yield, colourless oil, 95% pure).

Source