ChemicalBook CAS DataBase List 16-Dehydropregnenolone

16-Dehydropregnenolone synthesis

7synthesis methods

Product Name:16-Dehydropregnenolone
CAS Number:1162-53-4
Molecular formula:C21H30O2
Molecular Weight:314.46

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1162-53-4
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2857-75-2
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Yield:1162-53-4 95% ，2857-75-2 88%

Reaction Conditions:

Stage #1:diosgenin with acetic anhydride in acetic acid at 200; for 1 h;
Stage #2: with dihydrogen peroxide;(NH₄)3PMo₁₂O₄₀*6H₂O in dichloromethane;water for 2 h;Heating / reflux;
Stage #3: with potassium carbonate in dichloromethane;water for 2 h;Product distribution / selectivity;Heating / reflux;

Steps:

7
Example 7 Degradation of diosgenin to 16-dehydropregnenolone and 4R-methyl-δ-pentyl lactone 10 g of diosgenin, dissolved in acetic acid and acetic anhydride, was kept in the pressure kettle at 200° C. for one hour, then the low boilers were removed under reduced pressure and the residue was dissolved in 50 ml of dichloromethane. 18 mg of (NH₄)₃[P(Mo₁₂O₄₀)].6H₂O (0.1 mmol) and 5 ml of hydrogen peroxide (30% H₂O) were added, and this mixture was refluxed for 2 hours. After K₂CO₃was added, it was kept on refluxing for 2 hours. The mixture was concentrated, diluted with water, and filtrated to get 7.2 g of 16-dehydropregnenolone in 95% yield. The water layer was acidified and extracted with organic solvent to give 2.4 g of 4R-methyl-δ-pentyl lactone in 88% yield.

References:

SHANGHAI INSTITUTE OF ORGANIC CHEMISTRY, CHINESE ACADEMY OF SCIENCES US2006/166955, 2006, A1 Location in patent:Page/Page column 4

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