Reaction #1552075

Reaction equation

4-Isobutyl-6-methylcyclohex-3-enecarbaldehyde

KOtBu

MeI

→

orange oil

Yield 99.4%

4-Isobutyl-1,6-dimethylcyclohex-3-enecarbaldehyde

Yield 99.4%

Solvents

methylene chloride

Conditions

Workup

1. 1
   workup.STIRRINGthe suspension stirred for 30 min
2. 2
   Otherto return to room temperature
3. 3
   workup.STIRRINGAfter stirring for a further 3 h
4. 4
   Otherthe reaction crude
5. 5
   workup.ADDITIONwas poured onto brine (400 ml)
6. 6
   workup.STIRRINGstirred for 10 min
7. 7
   Otherto separate
8. 8
   ExtractionThe upper aqueous phase was extracted with methylene chloride (150 ml)
9. 9
   Dryingdried (Na2SO4)
10. 10
    Concentrationconcentrated in vacuo

Procedure

4-Isobutyl-6-methylcyclohex-3-enecarbaldehyde 3b (8 g, 44 mmol) was dissolved in methylene chloride (400 ml) and cooled to −3° C. with stirring and under nitrogen. KOtBu (6.7 g, 58 mmol) and MeI (19 g, 130 mmol) were added sequentially and the suspension stirred for 30 min before being allowed to return to room temperature. After stirring for a further 3 h the reaction crude was poured onto brine (400 ml), stirred for 10 min and the phases allowed to separate. The upper aqueous phase was extracted with methylene chloride (150 ml) and the organic phases combined, dried (Na2SO4) and concentrated in vacuo to give 8.5 g of an orange oil (8.5 g). The oil was purified by flash chromatography (MTBE/hexane 1:9) and combination of pure fractions gave 3c as a 7:3 mixture of diastereomers (7 g, colorless oil, 80% yield). 1 g of the oil was distilled to give a sample for olfactory assessment. (0.52 g, colourless oil, >99% pure).

Source