2-oxo-3-benzyl-4-methyl-7-vinyl-2H-1-benzopyrane → 2-Oxo-2H-chromene-7-carbaldehyde

HRID 1671497Notes

Reaction equation

HRID 1671497 reaction equation
[O:1]=[C:2]1[C:7](CC2C=CC=CC=2)=[C:6](C)[C:5]2[CH:16]=[CH:17][C:18]([CH:20]=C)=[CH:19][C:4]=2[O:3]1.I([O-])(=O)(=O)=[O:23].[Na+]>O1CCOCC1.O.CC(O)(C)C.[Os](=O)(=O)(=O)=O>[CH:20]([C:18]1[CH:19]=[C:4]2[C:5]([CH:6]=[CH:7][C:2](=[O:1])[O:3]2)=[CH:16][CH:17]=1)=[O:23]

Participants

7

Reactant 2

HCID 222183942-oxo-3-benzyl-4-methyl-7-vinyl-2H-1-benzopyraneHCID 23667635Sodium periodate

Product 1

HCID 120887742-Oxo-2H-chromene-7-carbaldehydeYield 119%

Reagents, catalysts & solvents 4

HCID 30318Osmium TetroxideCatalystHCID 962WaterSolventHCID 6386tert-ButanolSolventHCID 312751,4-DioxaneSolvent

Procedure

To the suspension of 2-oxo-3-benzyl-4-methyl-7-vinyl-2H-1-benzopyrane (16.0 g, Example 23) in dioxane (350 mL) and water (75 mL) is added osmium tetraoxide (1.45 mmol) in t-BuOH. The reaction mixture is stirred at room temperature for 30 minutes and sodium periodate (30 g) is added in portions. The solid is filtered out after 30 minutes stirring and the filtrate is partitioned between CH2Cl2 and water. Separation and the organic layer is washed further with H2O and dried over MgSO4. Evaporation of the organic solvent gives the desired 7-formyl coumarin intermediate (12.0 g).

Workup

  1. filtrationThe solid is filtered out after 30 minutes
  2. stirringstirring
  3. customthe filtrate is partitioned between CH2Cl2 and water
  4. customSeparation
  5. washthe organic layer is washed further with H2O
  6. dry with materialdried over MgSO4
  7. customEvaporation of the organic solvent

Sources & evidence

ORD record
ord-46e7201a085944e18e95236a7bc90db5
Source dataset
uspto-grants-2011_08
Patent number
US07994318B2

Reaction notes

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