Erythromycin → Erythromycin A enol ether

HRID 1582375

Reaction equation

HRID 1582375 reaction equation
[CH3:1][CH2:2][C@H:3]1[O:18][C:16](=[O:17])[C@H:15]([CH3:19])[C@@H:14]([O:20][C@@H:21]2[O:26][C@@H:25]([CH3:27])[C@H:24]([OH:28])[C@@:23]([O:30][CH3:31])([CH3:29])[CH2:22]2)[C@H:13]([CH3:32])[C@@H:12]([O:33][C@@H:34]2[O:39][C@H:38]([CH3:40])[CH2:37][C@H:36]([N:41]([CH3:43])[CH3:42])[C@H:35]2[OH:44])[C@@:11](O)([CH3:45])[CH2:10][C@@H:9]([CH3:47])[C:7](=[O:8])[C@H:6]([CH3:48])[C@@H:5]([OH:49])[C@@:4]1([OH:51])[CH3:50].C(=O)([O-])O.[Na+]>C(O)(=O)C>[CH3:1][CH2:2][C@H:3]1[O:18][C:16](=[O:17])[C@H:15]([CH3:19])[C@@H:14]([O:20][C@@H:21]2[O:26][C@@H:25]([CH3:27])[C@H:24]([OH:28])[C@@:23]([O:30][CH3:31])([CH3:29])[CH2:22]2)[C@H:13]([CH3:32])[C@@H:12]([O:33][C@@H:34]2[O:39][C@H:38]([CH3:40])[CH2:37][C@H:36]([N:41]([CH3:42])[CH3:43])[C@H:35]2[OH:44])[C@:11]2([CH3:45])[O:8][C:7](=[C:9]([CH3:47])[CH2:10]2)[C@H:6]([CH3:48])[C@@H:5]([OH:49])[C@@:4]1([OH:51])[CH3:50]

Participants

4

Reactant 2

HCID 12560ErythromycinHCID 516892Sodium Bicarbonate

Product 1

HCID 83954Erythromycin A enol etherYield 63.6%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

Glacial acetic acid solution of erythromycin A (12.4 g, 16.9 mmol) was stirred at room temperature for 2 hours, added slowly aqueous sodium hydrogen carbonate and neutralized. The reaction mixture was extracted with chloroform, dehydrated the organic layer with sodium sulfate, filtered off the sodium sulfate and removed the solvent by distillation to obtain crude substance. The crude substance was purified with silica gel chromatography (chloroform:methanol:aqueous ammonia=10:0.5:0.01→10:1:0.05) to obtain EM201 (7.7 g, 63%). Subsequently, potassium carbonate (1.4 g, 10.6 mmol) was added to the methanol solution (100 ml) of EM 201 (7.6 g, 10.6 mmol) and refluxed for 2 hours. After distilled off the solvent, the residue was dissolved in aqueous sodium hydrogen carbonate and extracted with chloroform. The mixture was dehydrated with sodium sulfate, filtered and removed the sodium sulfate, then the obtained crude substance was purified by silica gel chromatography (chloroform:methanol:aqueous ammonia=10:0.5:0.01→10:1:0.05) to obtain EM701 (5.9 g, 78%, white powder).

Workup

  1. extractionThe reaction mixture was extracted with chloroform
  2. filtrationfiltered off the sodium sulfate
  3. customremoved the solvent
  4. distillationby distillation
  5. customto obtain crude substance
  6. customThe crude substance was purified with silica gel chromatography (chloroform:methanol:aqueous ammonia=10:0.5:0.01→10:1:0.05)

Sources & evidence

ORD record
ord-89a604ed57824cd6b050648bd71b2039
Source dataset
uspto-grants-2004_05
Patent number
US06734292B1

Linked notes

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