63-05-8Relevant articles and documents
Direct Observation of a Dienolate Intermediate in the Base-Catalyzed Isomerization of 5-Androstene-3,17-dione to 4-Androstene-3,17-dione
Pollack, Ralph M.,Mack, Joseph P. G.,Eldin, Sherif
, p. 5048 - 5050 (1987)
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Prins,Reichstein
, p. 945,950 (1941)
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Determination of the Microscopic Rate Constants for the Base-Catalyzed Conjugation of 5-Androstene-3,17-dione
Pollack, Ralph M.,Zeng, Baifei,Mack, Joseph P. G.,Eldin, Sherif
, p. 6419 - 6423 (1989)
The hydroxide ion catalyzed isomerization of 5-androstene-3,17-dione (1) to 4-androstene-3,17-dione (2) proceeds through the formation of an intermediate dienolate ion (1-1).This dienolate ion has been observed in the ultraviolet spectrum (λmax ca. 256 nm) during the isomerization reaction.Rate constants for the formation of the dienolate ion and both its reversion to reactant (1) and its conversion to product (2) in aqueous solution were measured.In addition, the rate of exchange of the C-6 protons of 2 in D2O/MeOD was determined.These results enable a complete description of the reaction profile to be made, including all rate constants and the pKa values for 1 (12.7) and 2 (16.1).The possible relevance of these results to the mechanism of action of the enzyme 3-oxo-Δ5-steroid isomerase is briefly discussed.
Activity and inhibition of 3-beta-hydroxysteroid dehydrogenase/delta-5-4-isomerase in human skin
Toth,Szecsi,Julesz,Faredin
, p. 160 - 168 (1997)
Activity and inhibition of 3β-hydroxysteroid dehydrogenase/Δ5-4-isomerase, a key enzyme of biosynthesis of androgenic steroids, in human skin were studied. Whole-width dermal tissue specimens excised from various regions of the male and female body were investigated with an in vitro radioenzyme assay method using dehydroepiandrosterone as substrate. The Michaelis-Menten constant of the enzyme was found to be K(m) = 10 nM and the maximal velocity was V(max) = 0.625 pmol produced 4-androstene-3,17-dione/mg protein/20 min. Activity of 3β-hydroxysteroid dehydrogenase/Δ5-4-isomerase in male inguinal skin (n = 8) was 0.132-0.412, in female abdominal skin (n = 4) 0.140-0.255, in perineal skin (n = 4) 0.138-0.962 pmol/mg protein/20 min. The synthetic steroids cyproterone acetate, 4-MA and epostane proved to be potent inhibitors, IC50 values were 150, 6.2 and 1.45 nM, respectively.
Synthesis of Visible-Light–Activated Hypervalent Iodine and Photo-oxidation under Visible Light Irradiation via a Direct S0→Tn Transition
Matsuda, Yu,Matsumoto, Koki,Nagasawa, Sho,Nakajima, Masaya,Nemoto, Tetsuhiro
, p. 235 - 239 (2022/03/16)
Heavy atom-containing molecules cause a photoreaction by a direct S0→Tn transition. Therefore, even in a hypervalent iodine compound with a benzene ring as the main skeleton, the photoreaction proceeds under 365–400nm wavelength light, where UV-visible spectra are not observed by usual measurement method. Some studies, however, report hypervalent iodine compounds that strongly absorb visible light. Herein, we report the synthesis of two visible light-absorbing hypervalent iodines and their photooxidation properties under visible light irradiation. We also demonstrated that the S0→Tn transition causes the photoreaction to proceed under wavelengths in the blue and green light region.
Electrochemically Enabled One-Pot Multistep Synthesis of C19 Androgen Steroids
Sommer, Florian,Kappe, C. Oliver,Cantillo, David
supporting information, p. 6044 - 6049 (2021/03/15)
The synthesis of many valuable C19 androgens can be accomplished by removal of the C17 side chain from more abundant corticosteroids, followed by further derivatization of the resulting 17-keto derivative. Conventional chemical reagents pose significant drawbacks for this synthetic strategy, as large amounts of waste are generated, and quenching of the reaction mixture and purification of the 17-ketosteroid intermediate are typically required. Herein, we present mild, safe, and sustainable electrochemical strategies for the preparation of C19 steroids. A reagent and catalyst free protocol for the removal of the C17 side chain of corticosteroids via anodic oxidation has been developed, enabling several one-pot, multistep procedures for the synthesis of androgen steroids. In addition, simultaneous anodic C17 side chain cleavage and cathodic catalytic hydrogenation of a steroid has been demonstrated, rendering a convenient and highly atom economic procedure for the synthesis of saturated androgens.
A sodium trifluoromethanesulfinate-mediated photocatalytic strategy for aerobic oxidation of alcohols
Zhu, Xianjin,Liu, Can,Liu, Yong,Yang, Haijun,Fu, Hua
, p. 12443 - 12446 (2020/10/30)
A sodium trifluoromethanesulfinate-mediated photocatalytic strategy for the aerobic oxidation of alcohols has been developed for the first time, and the photoredox aerobic oxidation of secondary and primary alcohols provided the corresponding ketones and carboxylic acids, respectively, in high to excellent yields.
