Potassium Carbonate → 5-Hydroxy-2,2-dimethyl-8-oxo-10-propyl-2H,8H-pyrano[2,3-f]chromene-6-carbaldehyde

HRID 975534Notes

Reaction equation

HRID 975534 reaction equation
[OH:1][C:2]1[CH:11]=[C:10]([OH:12])[C:9]([CH:13]=[O:14])=[C:8]2[C:3]=1[C:4]([CH2:16][CH2:17][CH3:18])=[CH:5][C:6](=[O:15])[O:7]2.C(=O)([O-])[O-].[K+].[K+].Cl[C:26]([CH3:30])([CH3:29])[C:27]#[CH:28]>CC(=O)CC.CN(C=O)C.[I-].C([N+](CCCC)(CCCC)CCCC)CCC.[Cl-].[Cl-].[Zn+2]>[OH:12][C:10]1[C:9]([CH:13]=[O:14])=[C:8]2[C:3]([C:4]([CH2:16][CH2:17][CH3:18])=[CH:5][C:6](=[O:15])[O:7]2)=[C:2]2[O:1][C:26]([CH3:30])([CH3:29])[CH:27]=[CH:28][C:11]=12

Participants

8

Reactant 3

HCID 11430Potassium CarbonateHCID 706791-Butyne, 3-chloro-3-methyl-HCID 54661995,7-Dihydroxy-2-oxo-4-propyl-2H-chromene-8-carbaldehyde

Product 1

HCID 117231425-Hydroxy-2,2-dimethyl-8-oxo-10-propyl-2H,8H-pyrano[2,3-f]chromene-6-carbaldehydeYield 63.1%

Reagents, catalysts & solvents 4

HCID 67553Tetrabutylammonium IodideCatalystHCID 3007855ZincchlorideCatalyst2×HCID 6228DimethylformamideSolventHCID 6569Methyl Ethyl KetoneSolvent

Conditions

Temperature
60 °C

Procedure

To a solution of 6 (5.60 g, 22.5 mmol) in 2-butanone (125 mL) and dry DMF (10 mL) was added potassium carbonate (13.2 g, 95.5 mmol), tetrabutylammonium iodide (12.2 g, 33.0 mmol) and 3-chloro-3-methyl-1-butyne (11.2 g, 109 mmol). The reaction mixture was heated at 60° C. for 1 h, at which time anhydrous ZnCl2 (16 mL, 1 M solution in ether) was added. The reaction mixture was then heated at 60° C. for 12 h. Additional anhydrous ZnCl2 (8 mL, 1M solution in ether) was added, and the reaction mixture was kept at 60° C. for another 24 hr. The reaction mixture was cooled, quenched with saturated aqueous NH4Cl (150 mL), and extracted with EtOAc (3×100 mL). The combined organic layers were then washed with brine (1×50 mL), dried (MgSO4), concentrated and submitted to silica gel chromatography (solvent B) to obtain 7 (4.46 g, 63%) as a yellow solid: mp 116°-117° C.; 1H NMR (3:2 CDCl3 -CD3OD): δ 1.08 (t, J=7.3 Hz, 3H, --CH2CH3), 1.57 (s, 6H, --C(CH3)2), 1.68 (m, 2H, --CH2CH3), 2.90 (t, 2H, J=7.7 Hz, --CH2CH2CH3), 5.67 (d, 1H, J=10.0 Hz, H-3), 6.02 (s, 1H, H-9), 6.62 (d, 1H, J=10.0 Hz, H-4), 10.29 (s, 1H, --CHO); 13C NMR (3:2 CDCl3 -CD3OD): δ 12.79, 22.44, 27.15, 37.76, 79.87, 102.02, 103.08, 104.74, 110.18, 113.91, 126.31, 157.30, 157.54, 158.09, 158.91, 160.21, 192.12. Anal. Calcd for C18H18O5 : C, 68.78; H, 5.77. Found C, 68.77; H, 5.79.

Workup

  1. additionwas added
  2. temperatureThe reaction mixture was cooled
  3. customquenched with saturated aqueous NH4Cl (150 mL)
  4. extractionextracted with EtOAc (3×100 mL)
  5. washThe combined organic layers were then washed with brine (1×50 mL)
  6. dry with materialdried (MgSO4)
  7. concentrationconcentrated

Sources & evidence

ORD record
ord-bb054904658d420dbfc57e7ca485fbb4
Source dataset
uspto-grants-1997_03
Patent number
US05608085

Reaction notes

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