Lithium Hexamethyldisilazide → 2-(4-Bromo-2,6-dimethylphenyl)-5-[hydroxy(tetrahydropyran-4-yl)methyl]-3-methoxycyclopent-2-enone

HRID 514200Notes

Reaction equation

HRID 514200 reaction equation
[Br:1][C:2]1[CH:7]=[C:6]([CH3:8])[C:5]([C:9]2[C:10](=[O:16])[CH2:11][CH2:12][C:13]=2[O:14][CH3:15])=[C:4]([CH3:17])[CH:3]=1.C[Si]([N-][Si](C)(C)C)(C)C.[Li+].[CH2:28]1[CH:33]([CH:34]=[O:35])[CH2:32][CH2:31][O:30][CH2:29]1>O1CCCC1>[Br:1][C:2]1[CH:3]=[C:4]([CH3:17])[C:5]([C:9]2[C:10](=[O:16])[CH:11]([CH:34]([OH:35])[CH:33]3[CH2:32][CH2:31][O:30][CH2:29][CH2:28]3)[CH2:12][C:13]=2[O:14][CH3:15])=[C:6]([CH3:8])[CH:7]=1

Participants

5

Reactant 3

HCID 2733832Lithium HexamethyldisilazideHCID 9964078Tetrahydro-2H-pyran-4-carboxaldehydeHCID 668681542-(4-Bromo-2,6-dimethylphenyl)-3-methoxy-cyclopent-2-enone

Product 1

HCID 896013392-(4-Bromo-2,6-dimethylphenyl)-5-[hydroxy(tetrahydropyran-4-yl)methyl]-3-methoxycyclopent-2-enone

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Conditions

Temperature
-75 °C

Procedure

To a solution of 2-(4-bromo-2,6-dimethylphenyl)-3-methoxycyclopent-2-enone (7.5 g, 26.0 mmol) in anhydrous tetrahydrofuran (70 ml) under a nitrogen atmosphere is added lithium bis(trimethylsilyl)amide (44.6 ml, 31.0 mmol, 0.7M in tetrahydrofuran) dropwise at −75°C. After stirring for 40 minutes at this temperature a second solution of tetrahydropyranyl-4-carboxaldehyde (5.90 g, 52.0 mmol) in tetrahydrofuran (70 ml) is added over 20 minutes, and the resulting solution is stirred at −75°C. for 2 hours. After warming to room temperature the mixture is stirred for a further 2 hours, then is quenched with ice cold water (100 ml) and extracted with ethyl acetate (3×150 ml). Organics are combined, dried over sodium sulphate, filtered and the filtrate is concentrated in vacuo to afford 2-(4-bromo-2,6-dimethylphenyl)-5-[hydroxy(tetrahydropyran-4-yl)methyl]-3-methoxycyclopent-2-enone. This material is used directly in the next step without further purification.

Workup

  1. additionis added over 20 minutes
  2. temperatureAfter warming to room temperature the mixture
  3. stirringis stirred for a further 2 hours
  4. customis quenched with ice cold water (100 ml)
  5. extractionextracted with ethyl acetate (3×150 ml)
  6. dry with materialdried over sodium sulphate
  7. filtrationfiltered
  8. concentrationthe filtrate is concentrated in vacuo

Sources & evidence

ORD record
ord-1485ee43c98d429bb6d928d729131d75
Source dataset
uspto-grants-2015_08
Patent number
US09107415B2

Reaction notes

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