Tetrahydrofuran → 3',4'-Dihydroxyflavone

HRID 908913Notes

Reaction equation

HRID 908913 reaction equation
C([O:8][C:9]1[CH:10]=[C:11]([CH:40]=[CH:41][C:42]=1[O:43]CC1C=CC=CC=1)[C:12]1[O:13][C:14]2[C:19]([C:20](=[O:39])[C:21]=1OC(CCCCC(OCC1C=CC=CC=1)=O)=O)=[CH:18][CH:17]=[CH:16][CH:15]=2)C1C=CC=CC=1.C1COCC1>[OH-].[OH-].[Pd+2].CCO>[OH:8][C:9]1[CH:10]=[C:11]([CH:40]=[CH:41][C:42]=1[OH:43])[C:12]1[O:13][C:14]2[C:19]([C:20](=[O:39])[CH:21]=1)=[CH:18][CH:17]=[CH:16][CH:15]=2

Participants

5

Reactant 2

HCID 8028TetrahydrofuranHCID 11855572HCID 11855572, compound

Product 1

HCID 1457263',4'-DihydroxyflavoneYield 87.1%

Reagents, catalysts & solvents 2

HCID 9942167Palladium hydroxideCatalystHCID 702EthanolSolvent

Procedure

A mixture of 3′,4′-dibenzyloxy-3-(benzyloxycarbonylbutylcarbonyloxy)flavone (2.12 g, 3.16 mmol) and Pd(OH)2 (107 mg) in 9:1 THF:EtOH containing 0.05% acetic acid (50.0 mL) was treated with H2 under high pressure for 5 h. The reaction mixture was filtered (Celite) and concentrated to give a dark green solid. The green residue was purified by flash chromatography (30-90% THF/toluene+1% acetic acid) followed by crystallization from THF/petroleum spirits to yield the pure hemiadipate as a pale brown solid (0.70 g, 56%); mp=194-197° C.; 1H NMR (399.8 MHz, CDCl3); δ 1.44-1.62 (m, 4H, CH2CH2); 2.10 (t, 2H, J=6.8 Hz, CH2CO); 2.44 (t, 2H, J=6.8 Hz, CH2CO); 6.73 (d, 1H, J5′,6′=8.4 Hz, H5′); 7.09 (dd, 1H, J2′,6′=2.0 Hz, J5′,6′=8.4 Hz, H6′); 7.16-7.22 (m, 2H, H6, 2′); 732 (d, 1H, J7,8=8.0 Hz, H8); 7.48 (ddd, 1H, J5,7=1.6 Hz, J6,7=6.8 Hz, J7,8=8.0 Hz, H7); 7.94 (dd, 1H, J5,6=8.4 Hz, J5,7=1.6 Hz, H5). 13C NMR (100.5 MHz, d6-DMSO) δ 25.30, 25.62 (2C, CH2CH2CO2); 34.43, 34.81 (2C, CH2CO2); 116.59, 117.42, 119.98, 121.41, 122.06, 124.13, 126.51, 127.07, 133.32, 136.04, 146.97, 150.65, 156.35, 157.27 (14C, Ar); 171.97, 173.46, 179.95 (3C, C═O). Anal. Found; C, 68.89; H, 4.91; C21H18O6 requires C, 68.85; H, 4.95%. HRMS (ESI+) m/z 389.1000, C21H18NaO6 [M+Na]+ requires 389.1001.

Workup

  1. filtrationThe reaction mixture was filtered (Celite)
  2. concentrationconcentrated
  3. customto give a dark green solid
  4. customThe green residue was purified by flash chromatography (30-90% THF/toluene+1% acetic acid)
  5. customfollowed by crystallization from THF/petroleum spirits

Sources & evidence

ORD record
ord-a6397f96990e4bd197ec878f05611f6b
Source dataset
uspto-grants-2011_09
Patent number
US08017649B2

Reaction notes

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