Tin tetrachloride → HCID 23270450, compound

HRID 929749Notes

Reaction equation

HRID 929749 reaction equation
[CH3:1][O:2][C:3]1[CH:12]=[C:11]([O:13][CH3:14])[CH:10]=[C:9]2[C:4]=1[CH2:5][C:6](=O)[C@@H:7]([C:15]1[CH:20]=[CH:19][C:18]([O:21][CH3:22])=[C:17]([O:23][CH3:24])[CH:16]=1)[O:8]2.COC1C=C(OC)C=C2C=1C[C@H](O)[C@@H](C1C=CC(OC)=C(OC)C=1)O2.[Sn](Cl)(Cl)(Cl)Cl>ClCCl>[CH3:1][O:2][C:3]1[CH:12]=[C:11]([O:13][CH3:14])[CH:10]=[C:9]2[C:4]=1[CH:5]=[CH:6][CH:7]([C:15]1[CH:20]=[CH:19][C:18]([O:21][CH3:22])=[C:17]([O:23][CH3:24])[CH:16]=1)[O:8]2

Participants

5

Reactant 3

HCID 24287Tin tetrachlorideHCID 182659(2R,3S)-2-(3,4-Dimethoxyphenyl)-3,4-dihydro-5,7-dimethoxy-2H-1-benzopyran-3-olHCID 25068463HCID 25068463, compound

Product 1

HCID 23270450HCID 23270450, compoundYield 10.3%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

Dried (2R)-5,7,3′,4′-tetrakis(methyloxy)flavan-3-one (1) (200 mg, 0.581 mmol) and (2R,3S)-5,7,3′,4′-tetrakis(methyloxy)flavan-3-ol (5) (400 mg, 1.162 mmol, 2 eq.) was dissolved in dry dichloromethane (10 mL) and the mixture was cooled in ice/NaCl bath. Then tin(IV)chloride (1 M solution in dichloromethane, 1 mL, 1 mmol, 1.7 eq.) was added dropwise and the reaction mixture was stirred under argon in thawing ice/NaCl bath for 24 hours (TLC monitoring of consumption of starting materials). The reaction mixture was then filtered on a basic aluminium oxide and washed with ethyl acetate. Purification on silica preparative TLC plates (hexane-ethyl acetate 4:6) afforded (2R)-3-[(2R,3S)-5,7,3′,4′-tetrakis(methyloxy)-3-hydroxyflavan)]-5,7,3′,4′-tetramethoxyflavan-3-ene (6) (Rf 0.20, 40.1 mg, 0.060 mmol, 10%).

Workup

  1. custom(TLC monitoring of consumption of starting materials)
  2. filtrationThe reaction mixture was then filtered on a basic aluminium oxide
  3. washwashed with ethyl acetate
  4. customPurification on silica preparative TLC plates (hexane-ethyl acetate 4:6)

Sources & evidence

ORD record
ord-f4e1755afdd541e3abd77561a396898a
Source dataset
uspto-grants-2016_03
Patent number
US09296717B2

Reaction notes

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