p-Toluenesulfonic acid → Pseudomonic acid C

HRID 1395640Notes

Reaction equation

HRID 1395640 reaction equation
[CH3:1][C@@H:2]([C@@H:33]([OH:35])[CH3:34])[C@@H:3]1O[C@H:4]1[CH2:6][C@@H:7]1[C@@H:12]([OH:13])[C@@H:11]([OH:14])[C@H:10]([CH2:15]/[C:16](/[CH3:32])=[CH:17]/[C:18]([O:20][CH2:21][CH2:22][CH2:23][CH2:24][CH2:25][CH2:26][CH2:27][CH2:28][C:29]([OH:31])=[O:30])=[O:19])[O:9][CH2:8]1.C1(C)C=CC(S(O)(=O)=O)=CC=1.C(=O)(O)[O-].[K+].[Se-]C#N.[K+].C(O)CCC(C)C.O>COC(OC)(C)C.C(OCC)(=O)C>[CH3:1][C@@H:2]([C@@H:33]([OH:35])[CH3:34])/[CH:3]=[CH:4]/[CH2:6][C@@H:7]1[C@@H:12]([OH:13])[C@@H:11]([OH:14])[C@H:10]([CH2:15]/[C:16](/[CH3:32])=[CH:17]/[C:18]([O:20][CH2:21][CH2:22][CH2:23][CH2:24][CH2:25][CH2:26][CH2:27][CH2:28][C:29]([OH:31])=[O:30])=[O:19])[O:9][CH2:8]1

Participants

8

Reactant 5

HCID 6101p-Toluenesulfonic acidHCID 76960Potassium selenocyanateHCID 446596MupirocinHCID 516893Potassium BicarbonateHCID 88784357HCID 88784357, compound

Product 1

HCID 10413058Pseudomonic acid CYield 45%

Reagents, catalysts & solvents 2

HCID 64952,2-DimethoxypropaneSolventHCID 8857Ethyl AcetateSolvent

Procedure

Pseudomonic acid A (500 mgs) was dissolved in 2,2-dimethyoxypropane (50 ml) and treated with p-toluene sulphonic acid (few crystals). After 1 hour the solution was diluted with ethyl acetate, washed with brine and dried (MgSO4). The solution was evaporated in vacuo and the residue redissolved in water-methanol (1:1, 20 ml) and potassium bicarbonate (100 mgs, 1 eq) added. The solvents were removed in vacuo and potassium selenocyanate (432 mgs, 3 eq) and iso-hexylalcohol-water (9:1, 15 ml) added and reaction refluxed for 4 days. After filtering, the reaction mixture was diluted with ethyl acetate (20 ml) and extracted with aqueous sodium bicarbonate (3×20 ml). The aqueous extracts were combined and acidified with acetic acid under a layer of ethylacetate (20 ml). After stirring for ca. 1 hour the organic layer was separated and aqueous layer further extracted with ethylacetate (3×20 ml). The combined extracts were washed with brine, dried (MgSO4) and evaporated to an oil. Chromatography of the oil on silica (5 g) gave pure pseudomonic acid C (215 mgs, 45%).

Workup

  1. washwashed with brine
  2. dry with materialdried (MgSO4)
  3. customThe solution was evaporated in vacuo
  4. dissolutionthe residue redissolved in water-methanol (1:1, 20 ml)
  5. additionadded
  6. customreaction
  7. temperaturerefluxed for 4 days
  8. filtrationAfter filtering
  9. additionthe reaction mixture was diluted with ethyl acetate (20 ml)
  10. extractionextracted with aqueous sodium bicarbonate (3×20 ml)
  11. customwas separated
  12. extractionaqueous layer further extracted with ethylacetate (3×20 ml)
  13. washThe combined extracts were washed with brine
  14. dry with materialdried (MgSO4)
  15. customevaporated to an oil

Sources & evidence

ORD record
ord-8ae04c4f3e4047e181ce7d32a2af112f
Source dataset
uspto-grants-1980_05
Patent number
US04205002

Reaction notes

Loading…