Réaction #1552075

Équation de réaction

4-Isobutyl-6-methylcyclohex-3-enecarbaldehyde

KOtBu

MeI

→

orange oil

Rendement 99.4%

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

Rendement 99.4%

Solvants

methylene chloride

Conditions de réaction

Traitement

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

Mode opératoire

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