600538411
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Progesterone -> 17a-Hydroxyprogesterone -> Androstenedione -> Testosterone
The synthesis starts with the hydroxylation of C-17 of progesterone, to yield 17á-hydroxyprogesterone. The side chain is then cleaved to form
androstenedione
The keto group on C-17 is reduced to an alcohol to yield testosterone.
Anyone have any idea's of how this is performed... Journal articles seem to be no existent for this process (except for one's that are
realted to the P450 conversion in body)
Any help or steering in direction of paper or help would be GREATLY APPRECIATED...
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sparkgap
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Maybe we should rephrase your question:
"Are there any reducing agents that leave conjugated carbonyls unscathed?"
All the hydrides I know can't do that... 
(edit: Years of not performing an appreciably complex organic synthesis must have caught up to me. Thanks, Sandmeyer.  I have seen this done as well.)
sparky (~_~)
[Edited on 5-9-2005 by sparkgap]
"What's UTFSE? I keep hearing about it, but I can't be arsed to search for the answer..."
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Sandmeyer
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| Quote: | Originally posted by sparkgap
Maybe we should rephrase your question:
"Are there any reducing agents that leave conjugated carbonyls unscathed?"
All the hydrides I know can't do that...
sparky (~_~) |
He can reduce the a simpel keto group with NaBH4 in the presence of the a,b-unsaturated ketone elsewhere. Hydride is a hard nucleophile, it reacts
faster at C=O (1,2) than in 1,4-fashion. I even have the reference (NaBH4 for C=O to C-OH) for this particular compound, I can edit my post when I get
home to include it.
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Sandmeyer
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With NaBH4:
Norymberski; Woods; J. Chem. Soc.; 1955; 3426,3429.
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Can't get the above paper - unfortunately. But it has also been done with LAH:
Steroids. LI.1 4,6-Dien-3-ones2,3
Franz Sondheimer, C. Amendolla, G. Rosenkranz;
J. Am. Chem. Soc.; 1953; 75(23); 5932-5935.
http://rapidshare.de/files/4764838/Steroids.pdf.html
[Edited on 5-9-2005 by Sandmeyer]
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600538411
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Thanks for paper, most informative...
How does one get such old papers dated back to the 50's? Hard copies from university libraries? I bet most of the good informative papers would
be of equal age hence not onlice accessable generally...
I would like to look even futher backwards into how sex steroids are synthesised from things like Diosgenin and Cryptogenin... Did you know 90% of
steroid hormones are synthesised from ethnobotanical precursors?
| Quote: |
The majority of medicinally useful steroids are obtained by semi-synthesis from natural products: saponins, phytosterols, cholesterol and bile acids.
The immense commercial significance of spirostanol saponins as raw materials for steroid production stems from the discovery by Marker that their
aglycones can be easily converted into pregnane derivatives. An excellent historical perspective on the chemistry of Russell Marker was recently
described. The Marker degradation includes acetolysis of the spiroketal moiety followed by an oxidative cleavage of the double bond in the resulting
furost-20-enes (pseudosapogenins). The most important sapogenin from an economic standpoint is diosgenin that is extracted from Dioscorea species.
Oxidation of the corresponding pseudosapogenin with various reagents, such as CrO3/AcOH, KMnO4/NaIO4 or H2O2/AcOH has been intensively studied. These
reactions lead to 16-dehydro-pregnane derivatives by cleavage of the E ring. They are key intermediates in the synthesis of steroid hormones,
particularly corticosteroids and sex hormones.
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I would be great to know more information on on this is all done... There must be a paper or two that summarises all the different procedures used (as
there is with most things)... That would be the wholy grail of papers... Must be out there...
If anyone knows something that might help, please holla at your boy...
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S.C. Wack
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Many journals are fully available online, going back well over a hundred years. And searchable as well. For instance:
http://pubs.acs.org/about.html
http://www.rsc.org/Publishing/Journals/DigitalArchive/availa...
http://www.sciencedirect.com/science/journals
A small sample of what is out there. Some are free, but for most articles of interest one has to log in to a university proxy server for off-campus
access, or access subscribed journals from within the library.
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ChemHack
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Marker, Russell E.; Wagner, R. B.; Ulshafer, Paul R.; Wittbecker, Emerson L.; Goldsmith, Dale P. J.; Ruof, Clarence H. Sterols. CLX. Sapogenins. 72.
Steroidal sapogenins. Journal of the American Chemical Society (1947), 69 2167-2230. CODEN: JACSAT ISSN:0002-7863. CAN 42:5828 AN 1948:5828
CAPLUS
I am at two with nature.
- Woody Allen
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Sandmeyer
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| Quote: | | How does one get such old papers dated back to the 50's? |
library skills my friend, library skills... 
| Quote: | | Marker, Russell E.; Wagner, R. B.; Ulshafer, Paul R.; Wittbecker, Emerson L.; Goldsmith, Dale P. J.; Ruof, Clarence H. Sterols. CLX. Sapogenins. 72.
Steroidal sapogenins. Journal of the American Chemical Society (1947), 69 2167-2230. CODEN: JACSAT ISSN:0002-7863. CAN 42:5828 AN 1948:5828 CAPLUS
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7,3 megabytes of heterocyclic madnesss:
http://rapidshare.de/files/4875928/Steroidal_Sapogenins.pdf....
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fermium
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MR. T.
Mr. T can be synthesized by oxidation of the 4-androstenediol by dissolving in chloroform and stirring with active manganese dioxide for 24 - 48
hours. Then extract and crystallize
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Illegal Parkinson
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Don't know if this thread is still active. There is a way to go from 5-Androstenediol to DHEA high yield.
DOI:10.1021/jo00963a028
Convenient, high yield conversion of androst-5-ene-3.beta.,17.beta.-diol to dehydroisoandrosterone
Hiroshi Hosoda , David K. Fukushima , Jack Fishman
J. Org. Chem., 1973, 38 (24), pp 4209–4211
I just not understood where does 5-Androstenediol come from in the first place? That was the hurdle that i wasn't able to get my head around.
Incidently, the authors name (Fukushima) is the name of the Japanese nuclear reactor tsunami melt down.
[Edited on 16-4-2015 by Illegal Parkinson]
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