Methanol → 2,6-Dimethyl-6-(3-methyl-but-2-enyl)-cyclo-hex-2-enone

HRID 638790Notes

Reaction equation

[H-].[Na+].[CH3:3][C:4]1[CH:9]=[CH:8][CH:7]=[C:6]([CH3:10])[C:5]=1[OH:11].C(Cl)[CH:13]=[C:14]([CH3:16])[CH3:15].[CH3:18]O>C1(C)C=CC=CC=1.[Pd]>[CH3:3][C:4]1[C:5](=[O:11])[C:6]([CH3:18])([CH2:10][CH:13]=[C:14]([CH3:16])[CH3:15])[CH2:7][CH2:8][CH:9]=1

Participants

Conditions

Temperature: 5 °C

Procedure

Sodium hydride (60%, 85 g, 2.13 mol) was added portionwise to a solution of 2,6-dimethylphenol (250 g, 2.05 mol) in 2 L of toluene at 10-15° C. The resulting suspension was stirred for 45 min. The mixture was cooled to 5° C., and prenyl chloride (262 g, 2.13 mol, 85%) was added during 1.5 h keeping the temperature at 5° C. The mixture was then stirred for further 2 h at 10-15° C. Methanol (1 L) and palladium (2.5 g, 10% on charcoal) was added and the gray suspension was hydrogenated at 0.3 bar overpressure, keeping the temperature at 20-22° C. (ice bath). The suspension was then filtered through a pad of celite. The yellow filtrate was washed with water (0.5 L), aqueous sodium hydroxide (0.5 L) and brine (0.5 L), dried (MgSO4) and concentrated in vacuo. The residue was distilled over a 5 cm Vigreux column to yield 318 g (81%, bp 78-82° C./0.05 Torr) of a colorless oil.

Workup

customat 5° C
stirringThe mixture was then stirred for further 2 h at 10-15° C
customat 20-22° C.
filtrationThe suspension was then filtered through a pad of celite
washThe yellow filtrate was washed with water (0.5 L), aqueous sodium hydroxide (0.5 L) and brine (0.5 L)
dry with materialdried (MgSO4)
concentrationconcentrated in vacuo
distillationThe residue was distilled over a 5 cm Vigreux column
customto yield 318 g (81%, bp 78-82° C./0.05 Torr) of a colorless oil

Sources & evidence

ORD record: ord-f3f4a7c0c1e941a0a63367f6b1e4bfb2
Source dataset: uspto-grants-2010_04
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07691802B2

Reaction notes

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