Participants
| Role | Name | HCID | Charge |
|---|
| Reactant | Testosterone | HCID 6013 | — |
| Reactant | Methyl chloroformate | HCID 6586 | — |
| Solvent | Pyridine | HCID 1049 | — |
| Product | HCID 11439410 | HCID 11439410 | 76% |
Reaction Steps
Testosterone is treated with methyl chloroformate in pyridine to give 17β-methoxycarbonyloxyandrost4-en-3-one in 76% yield after recrystallization from methanol. A solution of the 17β-methoxycarbonyloxyandrost4-en-3-one in toluene is pyrolyzed at 460° C., and the crude product is recrystallized from acetone at room temperature to give androsta-4,16-dien-3-one in 90% yield. The androsta-4,16-dien-3-one is reduced at −55° with lithium tris(1,2-dimethylpropyl)hydridoborate in tetrahydrofuran to give a mixture of androsta-4,16-dien-3β-ol and androsta-4,16-dien-3α-ol; and chromatography on silica gel using dichloromethane/ethyl acetate gives pure androsta-4,16-dien-3β-ol and pure androsta-4,16-dien-3α-ol, each in 48% yield. These may be recrystallized (androsta-4,16-dien-3β-ol from cyclohexane at room temperature and androsta-4,16-dien-3α-ol from petroleum ether at −30° C.).
Provenance & Evidence
| DOI | 10.6084/m9.figshare.5104873.v1 |
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| Patent number | US08309539B2 |
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| Source dataset | uspto-grants-2012_11 |
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| ORD ID | ord-68a0ef1c488147128b37ab524e7eff3e |
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| Source note | uspto-grants-2012_11 |
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