Dimethyl Sulfide → (-)-4'-Demethylepipodophyllotoxin

HRID 1686180Notes

Reaction equation

HRID 1686180 reaction equation
[CH3:1][O:2][C:3]1[CH:4]=[C:5]([C@H:13]2[C@H:22]3[C:23]([O:25][CH2:26][C@@H:21]3[C@@H:20]([OH:27])[C:19]3[CH:18]=[C:17]4[O:28][CH2:29][O:30][C:16]4=[CH:15][C:14]2=3)=[O:24])[CH:6]=[C:7]([O:11][CH3:12])[C:8]=1[O:9]C.CS(O)(=O)=O.CSC>FC(F)(F)C(O)=O>[CH3:12][O:11][C:7]1[CH:6]=[C:5]([C@H:13]2[C@H:22]3[C:23]([O:25][CH2:26][C@@H:21]3[C@H:20]([OH:27])[C:19]3[CH:18]=[C:17]4[O:28][CH2:29][O:30][C:16]4=[CH:15][C:14]2=3)=[O:24])[CH:4]=[C:3]([O:2][CH3:1])[C:8]=1[OH:9]

Participants

5

Reactant 3

HCID 1068Dimethyl SulfideHCID 6395Methanesulfonic AcidHCID 10607Podophyllotoxin

Product 1

HCID 122797(-)-4'-DemethylepipodophyllotoxinYield 65,562,924%

Reagents, catalysts & solvents 1

HCID 6422Trifluoroacetic acidSolvent

Procedure

10 g (24 nmol) of podophyllotoxin are dissolved in 60 ml of trifluoroacetic acid. There are successively added 5.4 ml (72 mmol) of methanesulfonic acid. Stirring is carried out for 9 hours, 5.4 ml (72 mmol) of dimethyl sulfide are again added and stirring is carried out for 9 hours. The mixture is discharged onto ice (600 ml) and extracted with ethyl acetate (3×300 ml). The organic phases are washed with water and then with NaHCO3 solution until neutral. After drying over sodium sulfate, filtration and evaporation, there are obtained 6.3 g of 4′-demethylepipodophyllotoxin, which is used directly in the next step.

Workup

  1. stirringstirring
  2. waitis carried out for 9 hours
  3. extractionextracted with ethyl acetate (3×300 ml)
  4. washThe organic phases are washed with water
  5. dry with materialAfter drying over sodium sulfate, filtration and evaporation, there

Sources & evidence

ORD record
ord-f6c7af2217ec4cd5aeb26406552151b5
Source dataset
uspto-grants-2012_04
Patent number
US08148552B2

Reaction notes

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