2,6-Dimethyl-6-(3-methyl-but-2-enyl)-cyclo-hex-2-enone → HCID 22026342, compound

HRID 1793230Notes

Reaction equation

HRID 1793230 reaction equation
[CH3:1][C:2]1[C:3](=[O:14])[C:4]([CH3:13])([CH2:8][CH:9]=[C:10]([CH3:12])[CH3:11])[CH2:5][CH2:6][CH:7]=1.[CH3:15][Mg]Cl>C1COCC1.C1(C)C=CC=CC=1>[CH3:15][C:3]1([OH:14])[C:4]([CH3:13])([CH2:8][CH:9]=[C:10]([CH3:12])[CH3:11])[CH2:5][CH2:6][CH:7]=[C:2]1[CH3:1]

Participants

5

Reactant 2

HCID 115792582,6-Dimethyl-6-(3-methyl-but-2-enyl)-cyclo-hex-2-enoneHCID 178418332HCID 178418332, compound

Product 1

HCID 22026342HCID 22026342, compoundYield 78%

Reagents, catalysts & solvents 2

HCID 1140TolueneSolventHCID 8028TetrahydrofuranSolvent

Conditions

Temperature
15 °C

Procedure

2,6-Dimethyl-6-(3-methyl-but-2-enyl)-cyclohexenone (245 g, 1.28 mol) was added dropwise to a solution of methyl magnesium chloride (105 g, 1.41 mol) in THF (400 ml) and toluene (1.5 L) at room temperature. The temperature rose to 50° C. The mixture was stirred for additional 45 min, was then cooled to 15° C. and poured on ice. The organic phase was separated and washed with water (0.5 L) and brine (0.5 L), dried (MgSO4) and concentrated in vacuo. The residue was distilled over a 70 cm silverplated column (bp. 83-85° C./0.1 Torr) to yield 208 g (78%) product as a mixture of two diastereomers. 1H-NMR (400 MHz, CDCl3): 5.39 (bs, 1H, 3-H), 5.29-5.24 (m, 1H, 2′-H), 2.26-2.05 (m, 2H, 2′-H), 1.98-1.88 (m, 2H, 4-H), 1.75-1.71 (m, 6H, 2-CH3, 3′-CH3), 1.63 (s, 3H, 4′-H), 1.60 (bs, 1H, O—H), 1.50-1.46 (m, 2H, 5-H), 1.24/1.23 (2s, 3H, 1a,b-CH3), 0.96/0.90 (2s, 3H, 6a,b-CH3) ppm. GC/MS (EI), Isomer a: 208 (M+, 1), 190 (20), 175 (17), 147 (56), 121 (100), 105 (46), 98 (52), 83 (45), 43 (82). Isomer b: 208 (M+, 2), 190 (8), 175 (6), 147 (58), 121 (75), 105 (46), 98 (100), 83 (52), 43 (78). IR (ATR): 3476s, 2967vs, 2922vs, 1450s, 1376s, 1073vs, 921m, 902 m cm−1.

Workup

  1. customrose to 50° C
  2. additionpoured on ice
  3. customThe organic phase was separated
  4. washwashed with water (0.5 L) and brine (0.5 L)
  5. dry with materialdried (MgSO4)
  6. concentrationconcentrated in vacuo
  7. distillationThe residue was distilled over a 70 cm silverplated column (bp. 83-85° C./0.1 Torr)

Sources & evidence

ORD record
ord-6dd357ae782d47b2bc25946eb45b099c
Source dataset
uspto-grants-2006_07
Patent number
US07078570B2

Reaction notes

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