Androsta-1,4-diene-3,17-dione → (8'R,9'S,10'R,13'S,14'S)-10',13'-dimethylspiro[1,3-dioxolane-2,17'-7,8,9,11,12,14,15,16-octahydro-6H-cyclopenta[a]phenanthrene]-3'-one

HRID 1175662Notes

Reaction equation

HRID 1175662 reaction equation
[CH3:1][C@:2]12[CH2:19][CH2:18][C@H:17]3[C@@H:7]([CH2:8][CH2:9][C:10]4[C@:15]3([CH3:16])[CH:14]=[CH:13][C:12](=[O:20])[CH:11]=4)[C@@H:6]1[CH2:5][CH2:4][C:3]2=[O:21].[OH2:22].[C:23]1([CH3:33])C=CC(S(O)(=O)=O)=CC=1>C1C=CC=CC=1.C(O)CO>[CH2:33]1[CH2:23][O:22][C:3]2([CH2:4][CH2:5][C@H:6]3[C@H:7]4[C@H:17]([CH2:18][CH2:19][C@:2]23[CH3:1])[C@:15]2([CH3:16])[C:10](=[CH:11][C:12](=[O:20])[CH:13]=[CH:14]2)[CH2:9][CH2:8]4)[O:21]1

Participants

5

Reactant 2

HCID 13472Androsta-1,4-diene-3,17-dioneHCID 521998p-Toluenesulfonic acid monohydrate

Product 1

HCID 7061039(8'R,9'S,10'R,13'S,14'S)-10',13'-dimethylspiro[1,3-dioxolane-2,17'-7,8,9,11,12,14,15,16-octahydro-6H-cyclopenta[a]phenanthrene]-3'-oneYield 95%

Reagents, catalysts & solvents 2

HCID 174Ethylene GlycolSolventHCID 241BenzeneSolvent

Procedure

To a solution of androsta-1,4-dien-3,17-dione (1, 10.0 g) in benzene (600 ml) and ethylene glycol (90 ml) was added toluene-p-sulfonic acid monohydrate (0.3 g), and the solution was refluxed for 8-10 hours with a Dean-Stark apparatus for collecting water. The reaction mixture was cooled to room temperature, diluted with ethyl acetate and washed thoroughly with water, dilute sodium bicarbonate solution, water and finally with brine. The organic phase was dried over anhydrous magnesium sulfate, filtered and the organic solvent removed by rotary evaporator. The resultant solid was crystallized from methanol to give 17,17-ethylenedioxyandrosta-1,4-dien-3-one (2) as a white crystalline solid in 95% yield (11.0 g).

Workup

  1. temperaturethe solution was refluxed for 8-10 hours with a Dean-Stark apparatus
  2. customfor collecting water
  3. additiondiluted with ethyl acetate
  4. washwashed thoroughly with water, dilute sodium bicarbonate solution, water and finally with brine
  5. dry with materialThe organic phase was dried over anhydrous magnesium sulfate
  6. filtrationfiltered
  7. customthe organic solvent removed by rotary evaporator
  8. customThe resultant solid was crystallized from methanol

Sources & evidence

ORD record
ord-7a8f0d035dc74027bce9ed0cff7c06b3
Source dataset
uspto-grants-2010_11
Patent number
US07842680B2

Reaction notes

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