Sulfuric Acid → 2beta-Methoxy-3alpha-hydroxy-5alpha-pregnan-20-one

HRID 232809Notes

Reaction equation

HRID 232809 reaction equation
[O:1]1[C@H:3]2[CH2:4][C@H:5]3[C@:20]([CH3:22])([CH2:21][C@@H:2]12)[C@@H:19]1[C@H:8]([C@H:9]2[C@:16]([CH3:23])([CH2:17][CH2:18]1)[C@@H:12]([C:13](=[O:15])[CH3:14])[CH2:11][CH2:10]2)[CH2:7][CH2:6]3.S(=O)(=O)(O)O.[C:29](=O)(O)[O-:30].[Na+].CCOCC>CO.CCCCCC.C(OCC)(=O)C>[CH3:29][O:30][C@H:2]1[CH2:21][C@@:20]2([CH3:22])[C@@H:5]([CH2:6][CH2:7][C@@H:8]3[C@@H:19]2[CH2:18][CH2:17][C@@:16]2([CH3:23])[C@H:9]3[CH2:10][CH2:11][C@@H:12]2[C:13](=[O:15])[CH3:14])[CH2:4][C@@H:3]1[OH:1]

Participants

8

Reactant 4

HCID 1118Sulfuric AcidHCID 3283Diethyl EtherHCID 516892Sodium BicarbonateHCID 543466312alpha,3alpha-Epoxy-5alpha-pregnan-20-one

Product 1

HCID 700865362beta-Methoxy-3alpha-hydroxy-5alpha-pregnan-20-oneYield 60%

Reagents, catalysts & solvents 3

HCID 887MethanolCatalystHCID 887MethanolSolventHCID 21226206Ethyl acetate hexaneSolvent

Procedure

2α,3α-Epoxy-5α-pregnan-20-one (325 mg) in 80 mL of methanol was treated with a 1 mL solution of methanol containing 7 drops of concentrated sulfuric acid at room temperature. This mixture was stirred at this temperature for 10 minutes and then poured into a cold saturated solution of sodium bicarbonate and ether. The organic phase was washed several times with a small portion of bicarbonate, brine and dried over potassium carbonate. The concentrated organic phase was tested by TLC for complete reaction. Flash chromatography on silica gel with hexane/ethyl acetate solvent mixture (80:20) produced 209 mg (60% yield).

Workup

  1. washThe organic phase was washed several times with a small portion of bicarbonate, brine
  2. dry with materialdried over potassium carbonate
  3. customThe concentrated organic phase was tested by TLC for complete reaction

Sources & evidence

ORD record
ord-66b179af2e07488d9e1a744c1fba938d
Source dataset
uspto-grants-1997_01
Patent number
US05591733

Reaction notes

Loading…