Acetic Acid → 2-[3,4-Bis(acetyloxy)phenyl]-3,4-dihydro-2H-1-benzopyran-5,7-diyl diacetate

HRID 2419217Notes

Reaction equation

HRID 2419217 reaction equation
[C:1]([O:4][C:5]1[CH:6]=[C:7]([CH:27]=[CH:28][C:29]=1[O:30][C:31](=[O:33])[CH3:32])[CH:8]1[CH2:17][C:16](=O)[C:15]2[C:10](=[CH:11][C:12]([O:23][C:24](=[O:26])[CH3:25])=[CH:13][C:14]=2[O:19][C:20](=[O:22])[CH3:21])[O:9]1)(=[O:3])[CH3:2].[BH4-].[Na+].C(O)(=O)C.C(OC(=O)C)(=O)C>C1COCC1.C(O)C.N1C=CC=CC=1>[C:1]([O:4][C:5]1[CH:6]=[C:7]([CH:27]=[CH:28][C:29]=1[O:30][C:31](=[O:33])[CH3:32])[CH:8]1[CH2:17][CH2:16][C:15]2[C:10](=[CH:11][C:12]([O:23][C:24](=[O:26])[CH3:25])=[CH:13][C:14]=2[O:19][C:20](=[O:22])[CH3:21])[O:9]1)(=[O:3])[CH3:2]

Participants

7

Reactant 4

HCID 176Acetic AcidHCID 7918Acetic AnhydrideHCID 369614HCID 369614, compoundHCID 4311764Sodium borohydride2×

Product 1

HCID 1492192-[3,4-Bis(acetyloxy)phenyl]-3,4-dihydro-2H-1-benzopyran-5,7-diyl diacetateYield 36%

Reagents, catalysts & solvents 2

HCID 1049PyridineSolventHCID 21873804Tetrahydrofuran ethanolSolvent

Procedure

To a stirred solution of 1.0 grams 3',4',5,7-tetraacetoxyflavanone in 50 ml of 50% THF-ethanol was added 100 mg NaBH4. After 30 min., an additional 100 mg NaBH4 was added and stirring continued at room temperature for a total of 1 hour. The mixture was then poured into 200 ml of cold 0.5% acetic acid and extracted three times with 75 ml CHCl3. The combined CHCl3 extracts were dried (NA2SO4) and evaporated to give a thick oil. To the oil was added 6 ml acetic anhydride and 8 ml pyridine and this solution allowed to stand at room temperature overnight. After pouring into 100 ml ice water, the resulting emulsion was extracted with 125 ml chloroform and the chloroform washed with 100 ml ice water, 100 ml cold 3% HCl and 100 ml 0.5% NaHCO3. Drying (Na2SO4) and evaporating the CHCl3 gave an oil which was purified by chromatography on a 2.5 × 4.0 cm column of SILICAR CC-7. The first material to elute with 60% CHCl3 -hexane was 3',4',5,7-tetraacetoxyflavan, which after recrystallization from MeOH, was obtained in an amount of 345 mg (36% yield) mp 143°-4° C.

Workup

  1. customcontinued at room temperature for a total of 1 hour
  2. extractionextracted three times with 75 ml CHCl3
  3. dry with materialThe combined CHCl3 extracts were dried (NA2SO4)
  4. customevaporated
  5. customto give a thick oil
  6. waitto stand at room temperature overnight
  7. extractionthe resulting emulsion was extracted with 125 ml chloroform
  8. washthe chloroform washed with 100 ml ice water, 100 ml cold 3% HCl and 100 ml 0.5% NaHCO3
  9. dry with materialDrying (Na2SO4)
  10. customevaporating the CHCl3
  11. customgave an oil which
  12. customwas purified by chromatography on a 2.5 × 4.0 cm column of SILICAR CC-7
  13. washThe first material to elute with 60% CHCl3 -hexane
  14. customafter recrystallization from MeOH
  15. customwas obtained in an amount of 345 mg (36% yield) mp 143°-4° C.

Sources & evidence

ORD record
ord-fe04abc88133489a888cef5932249472
Source dataset
uspto-grants-1978_08
Patent number
US04105675

Reaction notes

Loading…