Ethyl (2E)-(2,3-dihydro-4H-1-benzopyran-4-ylidene)acetate → Ethyl (3,4-dihydro-2H-1-benzopyran-4-yl)acetate

HRID 1774007Notes

Reaction equation

HRID 1774007 reaction equation
[CH2:1]([O:3][C:4](=[O:16])/[CH:5]=[C:6]1\[CH2:7][CH2:8][O:9][C:10]2[C:15]\1=[CH:14][CH:13]=[CH:12][CH:11]=2)[CH3:2].C(OC(=O)/C=C1/CCOC2C/1=CC=CC=2)C>CCO.[Pd]>[CH2:1]([O:3][C:4](=[O:16])[CH2:5][CH:6]1[C:15]2[C:10](=[CH:11][CH:12]=[CH:13][CH:14]=2)[O:9][CH2:8][CH2:7]1)[CH3:2]

Participants

5

Reactant 2

HCID 14330280Ethyl (2E)-(2,3-dihydro-4H-1-benzopyran-4-ylidene)acetateHCID 86820652HCID 86820652, compound

Product 1

HCID 14203077Ethyl (3,4-dihydro-2H-1-benzopyran-4-yl)acetate

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 702EthanolSolvent

Conditions

Temperature
45 °C

Procedure

To a solution of chroman-(4E)-ylidene-acetic acid ethyl ester and chroman-(4Z)-ylidene-acetic acid ethyl ester (1.68 g, 7.47 mmol, 1 eq.) in EtOH (91 mL) under N2, palladium on activated carbon (10 wt. %, 168 mg) was added. The flask was carefully evacuated and refilled with H2 (3×). The black suspension was stirred at 45° C. under an H2-atmosphere for 18 hours. The black suspension was filtered through Celite. The Celite was rinsed with EtOH. The filtrate was concentrated in vacuo to give (±)-chroman-4-yl-acetic acid ethyl ester as a grey oil. The product was used without further purification.

Workup

  1. customThe flask was carefully evacuated
  2. additionrefilled with H2 (3×)
  3. filtrationThe black suspension was filtered through Celite
  4. washThe Celite was rinsed with EtOH
  5. concentrationThe filtrate was concentrated in vacuo

Sources & evidence

ORD record
ord-d9d07731092a44d9a0ccce828e074ad2
Source dataset
uspto-grants-2016_02
Patent number
US09255090B2

Reaction notes

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