Water → HCID 21466121, compound

HRID 1940212Notes

Reaction equation

HRID 1940212 reaction equation
[CH3:1]C(C)([O-])C.[K+].[CH3:7][CH:8]([CH3:27])[C:9]([O:11][C:12]1[C:13]([CH3:26])=[C:14]([CH3:25])[C:15]2[O:19][C:18]([CH3:21])([CH3:20])[C:17](=O)[C:16]=2[C:23]=1[CH3:24])=[O:10].O>[Br-].C[P+](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1.O1CCCC1>[CH2:1]=[C:17]1[C:16]2[C:23]([CH3:24])=[C:12]([O:11][C:9](=[O:10])[CH:8]([CH3:27])[CH3:7])[C:13]([CH3:26])=[C:14]([CH3:25])[C:15]=2[O:19][C:18]1([CH3:20])[CH3:21]

Participants

6

Reactant 3

HCID 962WaterHCID 23665647Potassium tert-butoxideHCID 54110445HCID 54110445, compound

Product 1

HCID 21466121HCID 21466121, compoundYield 85.2%

Reagents, catalysts & solvents 2

HCID 74505Methyltriphenyliphosphonium bromideCatalystHCID 8028TetrahydrofuranSolvent3×

Procedure

Potassium tert-butoxide (1.53 g, 13.68 mmol) is added portionwise at 0° C. and under nitrogen to a suspension of methyltriphenylphosphonium bromide (4.9 g, 13.68 mmol) in dry tetrahydrofuran (57 mL) and the reaction mixture is stirred for 1 hr at room temperature. The 5-(2-methyl-propionoxy)-2,2,4,6,7-pentamethyl-2,3-dihydro-1-benzofuran-3-one (3.31 g, 11.4 mmol) in dry tetrahydrofuran (20 mL) is dropwise added at 0° C. to the yellow suspension and the reaction is stirred overnight at room temperature. Water is added and most of tetrahydrofuran is evaporated under reduced pressure. The residue is taken up in ethyl acetate, washed with brine, dried (magnesium sulfate) and the solvent is evaporated to dryness. Purification by flash chromatography eluting with heptane/ethyl acetate 95:5 and then 90:10 gave 2.8 g (85%) of 3-methylene-5-(2-methylpropionoxy)-2,2,4,6,7-pentamethyl-2,3-dihydro-1-benzofuran as a yellow oil. Rf=0.79 (heptane/ethyl acetate 70:30)

Workup

  1. stirringthe reaction is stirred overnight at room temperature
  2. customis evaporated under reduced pressure
  3. washwashed with brine
  4. dry with materialdried (magnesium sulfate)
  5. customthe solvent is evaporated to dryness
  6. customPurification by flash chromatography
  7. washeluting with heptane/ethyl acetate 95:5

Sources & evidence

ORD record
ord-c46bdc35bfcb472289eec89a8cdc13b1
Source dataset
uspto-grants-1997_12
Patent number
US05698696

Reaction notes

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