Ethyl oxoacetate → Ethyl 4-oxo-3,4-dihydro-2H-pyran-2-carboxylate

HRID 1745410

반응식

HRID 1745410 반응식
[CH2:1]([O:3][C:4](=[O:7])[CH:5]=[O:6])[CH3:2].CO[CH:10]=[CH:11][C:12](=[CH2:18])[O:13][Si](C)(C)C>C1C=CC=CC=1.[Cl-].[Zn+2].[Cl-]>[CH2:1]([O:3][C:4]([CH:5]1[CH2:18][C:12](=[O:13])[CH:11]=[CH:10][O:6]1)=[O:7])[CH3:2]

참가 물질

5

반응물 2

HCID 70211Ethyl oxoacetateHCID 1010511-Methoxy-3-trimethylsilyloxy-1,3-butadiene

생성물 1

HCID 22495097Ethyl 4-oxo-3,4-dihydro-2H-pyran-2-carboxylate수율 75%

시약·촉매·용매 2

HCID 3007855Zincchloride촉매HCID 241Benzene용매

실험 절차

A solution of glyoxylic acid ethyl ester, polymer form (2.02 g, 8.9 mmol) and (3-methoxy-1 methylene-allyloxy)trimethylsilane (1.9 ml, 8.9 mmol, Danishefsky's diene) in benzene (12 ml) was placed under nitrogen. Zinc chloride (0.5 N in tetrahydrofuran, 8.9 ml, 4.45 mmol) was added and the reaction stirred at ambient temperature for 72 hours. The mixture was concentrated in vacuo, diluted with ethyl acetate (100 ml) and washed with 1 N hydrochloric acid (20 ml), saturated sodium bicarbonate (20 ml), and brine (20 ml). The organic layer was dried (Na2SO4), filtered, and the solvent evaporated in vacuo. The residue was purified by silica gel chromatography using a mixture of ethyl acetate/hexane (1:2) as eluent. Pure fractions were collected and the solvent evaporated in vacuo which afforded 1.2 g (75%) of 4-oxo-3,4-dihydro-2H-pyran-2-carboxylic acid ethyl ester as an oil.

후처리

  1. concentrationThe mixture was concentrated in vacuo
  2. additiondiluted with ethyl acetate (100 ml)
  3. washwashed with 1 N hydrochloric acid (20 ml), saturated sodium bicarbonate (20 ml), and brine (20 ml)
  4. dry with materialThe organic layer was dried (Na2SO4)
  5. filtrationfiltered
  6. customthe solvent evaporated in vacuo
  7. customThe residue was purified by silica gel chromatography
  8. additiona mixture of ethyl acetate/hexane (1:2) as eluent
  9. customPure fractions were collected
  10. customthe solvent evaporated in vacuo which

출처 및 근거

ORD 기록
ord-92bd6faa833b4c6397d99a0800f07e7f
출처 데이터셋
uspto-grants-2006_03
특허 번호
US07019026B1

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