p-Toluenesulfonic acid → Acetoacetic Acid

HRID 373869Notes

Reaction equation

HRID 373869 reaction equation
[C:1]([O:4][C:5](=[O:7])[CH3:6])(=[O:3])[CH3:2].[C:8]1([CH3:18])C=CC(S(O)(=O)=O)=C[CH:9]=1.Cl(O)(=O)(=O)=[O:20].[C:24](=[O:27])([O-])[O-:25].[Na+].[Na+].[BH4-].[Ca+2].[BH4-]>C(O)C.C(OCC)(=O)C.N1C=CC=CC=1>[C:1]([O:4][C:5](=[O:7])[CH3:6])(=[O:3])[CH3:2].[CH3:9][C:8]([CH2:18][C:24]([OH:25])=[O:27])=[O:20]

Participants

10

Reactant 5

HCID 6101p-Toluenesulfonic acidHCID 7918Acetic Anhydride2×HCID 10340Sodium CarbonateHCID 24247Perchloric AcidHCID 5070074HCID 5070074, compound

Product 2

HCID 96Acetoacetic AcidHCID 7918Acetic Anhydride

Reagents, catalysts & solvents 3

HCID 702EthanolSolventHCID 1049PyridineSolventHCID 8857Ethyl AcetateSolvent

Procedure

If 2β,19-(ethylene)-androst-4-ene-3,17-dione is reduced with sodium borohydride in ethanol, the corresponding Δ4 -3β,17β-diol is obtained. To obtain the Δ5 -3β,17β-diol, the 2β,19-(ethylene)androst-4-ene-3,17-dione is first converted to the corresponding 3-acetoxy-3,5-diene. This conversion is accomplished by treating the dione with acetic anhydride in the presence of a catalytic amount of an acid such as p-toluenesulfonic acid followed by the addition of pyridine, or the conversion can be accomplished by reacting the dione with an excess of acetic anhydride and a catalytic amount of 70% aqueous perchloric acid using ethyl acetate as the solvent followed by neutralization with sodium carbonate. The 3-acetoxy-3,5-diene is then treated with calcium borohydride in ethanol at -15° C. to give the desired Δ5 -diol. Subsequent treatment of the diol with an anhydride, such as acetic anhydride, gives the corresponding diacetate.

Workup

  1. customto give the

Sources & evidence

ORD record
ord-7067a1a7b9f64d5f9b38bc8e378c5d4d
Source dataset
uspto-grants-1992_11
Patent number
US05166201

Reaction notes

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