- Is the magnetic shielding effect of a lactone group the simple sum of those of a ketone and an ether?
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3-Oxo-4-oxa-5α-androstanone (1) was synthesized in order to obtain the NMR shielding parameters for lactone group. The assignment of 1H-NMR and substituent-induced shifts (SIS) from the corresponding androstanone (2) are presented. A simple sum of the magnetic shieldings of ketone and ether can satisfactorily reproduce the observed SIS values due to the lactone group of 1.
- Fukazawa, Yoshimasa,Haino, Takeharu,Kondoh, Yoshiaki
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- Shielding effect of ether C-O bond obtained from proton chemical shifts of 4-oxa-5α- and 4-oxa-5β-androstan-17-ones
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4-Oxa-5α- and 4-oxa-5β-androstanones (1 and 2) were synthesized in order to obtained the NMR shielding parameters for the ether C-O bond. The complete NMR assignment of both the proton and carbon atoms for these compounds and substituent-induced shifts (SIS) from the corresponding androstanones (3 and 4) are presented. The comparison of the molecular structure obtained by MM3 calculation with that of X-ray crystallographic analysis disclosed that the former structure is completly superimposable to the latter in both of the compounds 1 and 2. A combination of the electric field effect and the anisotropy of the magnetic susceptibility of the C-O bond can successfully reproduce the observed SIS values for these androstanones.
- Yang, Yanyan,Haino, Takeharu,Usui, Shuji,Fukazawa, Yoshimasa
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- Hemisynthesis of 2,3,4-13C3-1,4-androstadien-3,17-dione: A key precursor for the synthesis of 13C3-androstanes and 13C3-estranes
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In this contribution, we describe two simple and efficient routes for the preparation of keto-aldehyde 1, a key intermediate for the synthesis of 13C3-androstanes and 13C3-estranes. In the first route, the targeted aldehyde 1 was obtained in 40% overall yield from 1,4-androstadien-3,17-dione (3 mmol scale) via a two-step sequence involving a one-pot, abnormal ozonolysis/sulfur oxidation/retro-Michael/ozonolysis process. Alternatively, a second route from 4-androsten-3,17-dione, using a six-step sequence, was optimized to produce 40 mmol batches of the key intermediate 1 in 42% overall yield. At the final stage, the A-ring was reconstructed through a Wittig reaction with the 1-triphenylphosphoranylidene-13C3-2-propanone 2, followed by an intramolecular condensation assisted by thioacetic acid via a Michael addition/retro-Michael reaction sequence to provide 2,3,4-13C3-1,4-androstadien-3,17-dione.
- Berthonneau, Clément,Nun, Pierrick,Rivière, Matthieu,Pauvert, Mickael,Dénès, Fabrice,Lebreton, Jacques
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p. 3727 - 3737
(2018/04/14)
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- CYP11B, CYP17, AND/OR CYP21 INHIBITORS
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Provided herein are inhibitors of CYP11B, CYP17, and/or CYP21 enzymes of Formula (Z), (IX), (X), (XI), (XII), (XIII), (XIV), (XV), (XVI), or (XVII). Also described herein are pharmaceutical compositions that include at least one compound described herein and the use of a compound or pharmaceutical composition described herein to treat androgen-dependent diseases, disorders and conditions. Formula (Z)
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Page/Page column 179
(2012/06/30)
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- NOVEL CYP17 INHIBITORS
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Provided herein are inhibitors of CYP17 enzyme. Also described herein are pharmaceutical compositions that include at least one compound described herein and the use of a compound or pharmaceutical composition described herein to treat androgen-dependent diseases, disorders and conditions.
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Page/Page column 48
(2011/08/04)
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- DECAHYDRO-1H-INDENOQUINOLINONE AND DECAHYDRO-3H-CYCLOPENTAPHENANTHRIDINONE CYP17 INHIBITORS
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Provided herein are inhibitors of CYP17 enzyme. Also described herein are pharmaceutical compositions that include at least one compound described herein and the use of a compound or pharmaceutical composition described herein to treat androgen-dependent diseases, disorders and conditions.
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Page/Page column 42
(2010/05/13)
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- A microwave promoted and Lewis acid catalysed solventless approach to 4-azasteroids
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The preparation of 3-oxo-4-azasteroid from A-nor-3,5-secosteroid-3-oic acid is described in a solventless condition catalysed by Lewis acid under microwave irradiation. We utilized urea as an environmentally benign source for the generation of ammonia for the aza cyclization reaction.
- Borthakur, Moyurima,Boruah, Romesh C.
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p. 637 - 641
(2008/09/19)
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- New approach to 3-oxo-4-aza-5α-androst-1-ene-17β-(N-tert- butylcarboxamide)
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We describe the synthesis of 3-oxo-4-aza-5α-androst-1-ene-17β- (N-tert-butylcarboxamide) (finasteride) from 4-androstene-3,17-dione (AD) in seven steps in an overall yield of 18.6% via oxidation, ammoniumation, dehydration, and dehydrogenation.
- Jiang, Zhong-Xing,Ye, Jing-Quan,Jiang, Li,Zhao, Ying-Sheng
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p. 690 - 693
(2007/10/03)
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- Peroxide oxidation of Δ4-3-ketosteroids
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Treatment of Δ4-3-ketosteroids with tert-butyl hydroperoxide in the presence of lithium hydroxide leads to the formation of the corresponding 4β,5β epoxides stereospecifically and in good yield.The stereospecificity of this reaction is explicable in terms of the accepted mechanism for the hydrogen peroxide epoxidation of Δ4-3-ketosteroids.The use of aqueous sodium peroxide as oxidant leads to the production of the corresponding Δ4-3,6-diones.A mechanism for this reaction is proposed in which the key step is autooxidation of the corresponding deconjugated Δ5-3-ketone, produced from the starting material in situ by the action of the reagents.Lithium peroxide does not oxidize androst-4-ene-3,17-dione at C-6, but produces the 4,5-epoxides in low yield together with an A-nor-3,5-secoacid.
- Holland, Herbert L.,Riemland, Elly,Ulrich, Daum
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p. 1919 - 1923
(2007/10/02)
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