Sodium borohydride → (20Z)-20-Formamido-3-methoxypregna-3,5,17(20)-triene-9alpha,21-diol

HRID 1613974Notes

Reaction equation

HRID 1613974 reaction equation
[BH4-].[Na+].[H-].[Al+3].[Li+].[H-].[H-].[H-].[CH:9]([NH:11]/[C:12](=[C:18]1/[CH2:19][CH2:20][C@@H:21]2[C@:35]/1([CH3:36])[CH2:34][CH2:33][C@@:32]1([OH:37])[C@H:22]2[CH2:23][CH:24]=[C:25]2[C@:30]1([CH3:31])[CH2:29][CH2:28][C:27]([O:38][CH3:39])=[CH:26]2)/[C:13](OCC)=[O:14])=[O:10].C(C(C(C([O-])=O)O)O)([O-])=O.[K+].[Na+]>O1CCCC1.C(O)C>[CH:9]([NH:11]/[C:12](=[C:18]1/[CH2:19][CH2:20][C@@H:21]2[C@:35]/1([CH3:36])[CH2:34][CH2:33][C@@:32]1([OH:37])[C@H:22]2[CH2:23][CH:24]=[C:25]2[C@:30]1([CH3:31])[CH2:29][CH2:28][C:27]([O:38][CH3:39])=[CH:26]2)/[CH2:13][OH:14])=[O:10]

Participants

7

Reactant 4

HCID 4311764Sodium borohydride2×HCID 9855836Potassium sodium tartarateHCID 21226445Aluminium lithium hydride2×HCID 86746637Ethyl (20Z)-20-formamido-9alpha-hydroxy-3-methoxypregna-3,5,17(20)-trien-21-oate

Product 1

HCID 86746638(20Z)-20-Formamido-3-methoxypregna-3,5,17(20)-triene-9alpha,21-diolYield 24.7%

Reagents, catalysts & solvents 2

HCID 702EthanolSolventHCID 8028TetrahydrofuranSolvent

Conditions

Temperature
5 °C

Procedure

Under a nitrogen atmosphere sodium borohydride (0.53 g) and lithium aluminium hydride (0.65 g) were added to a stirred solution of ethyl (20Z)-20-formamido-9α-hydroxy-3-methoxypregna-3,5,17(20)-trien-21-oate (4.85 g, prepared according to example 10), in dry tetrahydrofuran (100 ml) at 0° C. The reaction mixture was stirred at 5° C. for 2 hours, after which another 0.54 g of sodium borohydride and 0.65 g of lithium aluminium hydride were added. Stirring was continued at 5° C. for 1.5 hours, then ethanol (50 ml) was added dropwise to decompose excess reducing agent. After adding 60 ml of an aqueous solution of sodium potassium tartrate, the reaction mixture was filtered and extracted with ethyl acetate. The organic phase was washed with an aqueous sodium carbonate solution and with water, dried (MgSO4) and concentrated under reduced pressure. The residue (3.02 g) was purified by column chromatography (toluene/acetone 2/1 containing 0,1% triethylamine) to provide 1.08 g of the title compound.

Workup

  1. stirringStirring
  2. waitwas continued at 5° C. for 1.5 hours
  3. filtrationthe reaction mixture was filtered
  4. extractionextracted with ethyl acetate
  5. washThe organic phase was washed with an aqueous sodium carbonate solution and with water
  6. dry with materialdried (MgSO4)
  7. concentrationconcentrated under reduced pressure
  8. customThe residue (3.02 g) was purified by column chromatography (toluene/acetone 2/1 containing 0,1% triethylamine)

Sources & evidence

ORD record
ord-715b762d55a643e2b6f8f84ec819ee10
Source dataset
uspto-grants-1993_03
Patent number
US05194602

Reaction notes

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