Hydrochloric Acid → (5alpha)-21-(Acetyloxy)pregn-2-ene-11,20-dione

HRID 233505Notes

Reaction equation

HRID 233505 reaction equation
[C:1]([O:4][CH2:5][C:6](=[O:38])[C@@H:7]1[C@:24]2([CH3:25])[C@H:10]([C@H:11]3[C@H:21]([C:22](=[O:26])[CH2:23]2)[C@:19]2([CH3:20])[C@H:14]([CH2:15][C@@H:16](OS(C4C=CC(C)=CC=4)(=O)=O)[CH2:17][CH2:18]2)[CH2:13][CH2:12]3)[CH2:9][CH2:8]1)(=[O:3])[CH3:2].O.Cl>N1C(C)=CC(C)=CC=1C>[C:1]([O:4][CH2:5][C:6](=[O:38])[C@@H:7]1[C@:24]2([CH3:25])[C@H:10]([C@H:11]3[C@H:21]([C:22](=[O:26])[CH2:23]2)[C@:19]2([CH3:20])[C@H:14]([CH2:15][CH:16]=[CH:17][CH2:18]2)[CH2:13][CH2:12]3)[CH2:9][CH2:8]1)(=[O:3])[CH3:2]

Participants

5

Reactant 3

HCID 313Hydrochloric AcidHCID 962WaterHCID 10506735HCID 10506735, compound

Product 1

HCID 53989573(5alpha)-21-(Acetyloxy)pregn-2-ene-11,20-dioneYield 78.5%

Reagents, catalysts & solvents 1

HCID 79532,4,6-TrimethylpyridineSolvent

Procedure

A solution of (3β,5α)-21-(acetyloxy)-3-{[(4-methylphenyl)sulfonyl]oxy}pregnane-11,20-dione (35 g) in collidine (350 ml) was heated under reflux for 2 h. The reaction mixture was poured into water (3.5 l) containing hydrochloric acid (614 ml; 5M) and the precipitated solid was filtered off, washed with water and dissolved in dichloromethane. After drying the solution over sodium sulfate, the solvent was removed under reduced pressure. Crystallisation of the residue from methanol gave a mixture (3:1) (18.8 g) of (5α)-21-(acetyloxy)pregn-2-ene-11,20-dione and its 3-ene-isomer.

Workup

  1. temperatureunder reflux for 2 h
  2. filtrationthe precipitated solid was filtered off
  3. washwashed with water
  4. dissolutiondissolved in dichloromethane
  5. dry with materialAfter drying the solution over sodium sulfate
  6. customthe solvent was removed under reduced pressure
  7. customCrystallisation of the residue from methanol

Sources & evidence

ORD record
ord-1aee45b670354ffc9de0574ab8012a15
Source dataset
uspto-grants-1997_01
Patent number
US05593983

Reaction notes

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