6247-88-7Relevant academic research and scientific papers
Catalytic removal of tert-butyldimethylsilyl (TBS) ether by PVP-I
Ke, Yanxiong,Lu, Guangying,Ren, Jiangmeng,Wang, Di,Zeng, Bu-Bing
, (2019/09/06)
A mild, efficient and rapid protocol the deprotection of alcoholic TBDMS ethers using PVP-1 as catalyst in methanol, the procedure of deprotection of various TBDMS ethers were found to be very convenient, easy work-up, high yielding.
Stereo selective one-step reduction in the steroid skeleton 4 - ene -3 - ketone as a 3 α - hydroxy - 5 β - hydrogen A/B cis structure method
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Paragraph 0022; 0041; 0042; 0043, (2017/02/17)
The invention relates to a method for one-step reduction of a 4-ene-3-one structure in a steroid skeleton into an A/B cis-3a-hydroxy-5b-hydrogen structure, belonging to the fields of organic chemistry and drug synthesis. According to the method, under the conditions of room temperature and an environment of absolute ethyl alcohol, cuprous chloride is used as a catalyst and sodium borohydride is used as a reducing agent for high-selectivity conversion of the 4-ene-3-one structure of 4-AD, ADD and derivatives thereof into the A/B cis-3a-hydroxy-5b-hydrogen structure. According to results of X-diffraction results, an androstane-3a-hydroxy-5b-hydrogen-17-one product prepared by using the method has a stereo structure; reaction conditions are mild and simple; used reagents are cheap and easily available; operation is convenient; good repeatability is realized, and high yield is obtained. The method provided by the invention lays a good foundation for exploitation of resourceful utilization of sterol and for research on synthesis of drugs like ursodesoxycholic acid, chenodeoxycholic acid, deoxycholic acid and ecdyson with the A/B cis-structure with non-cholic acid type steroids as raw materials.
Heterogeneous Catalysis in Carbonyl Regeneration from 1,3-Dithiolanes and 1,3-Dithianes by Zirconium Sulfophenyl Phosphonate
Curini, Massimo,Marcotullio, Maria Carla,Pisani, Emanuela,Rosati, Ornelio,Costantino, Umberto
, p. 769 - 770 (2007/10/03)
Layered zirconium sulfophenyl phosphonate was found to be an efficient heterogeneous catalyst for mild hydrolysis of 1,2 dithiolanes and 1,3 dithianes to their corresponding carbonyl compounds.
Triethylamine-photosensitized reduction of a ketone via a chemical sensitization mechanism
Wu, Zheng-Zhi,Hug, Gordon L.,Morrison, Harry
, p. 1812 - 1816 (2007/10/02)
Photolysis of acetonitrile solutions of 3β-hydroxy-5α-androstan-17-one (1), or its 3β-methoxy analogue (5), and triethylamine (TEA) with 254-nm light leads to reduction of the 17-keto group with high stereoselectivity. By contrast, Norrish type I products are exclusively observed when the photolysis is carried out in cyclohexane, and products from both α-cleavage and reduction are observed in ether or THF. Excitation of TEA in acetonitrile results in the photoionization of the amine to form a radical cation and a solvent radical anion. Several possible mechanisms for reduction of ground-state ketones by these species, or radicals derived therefrom, are outlined. The limiting quantum efficiency for reduction of 1 is 0.17. The results observed in cyclohexane are explained by singlet-singlet energy transfer from the TEA excited state to the ketone, while both photoionization and energy transfer appear to be operating in the ethereal solvents.
A New Procedure for Dethioacetalization via Equilibrium Exchange with Aqueous Acetone, Paraformaldehyde and Amberlyst 15 as Acidic Catalyst
Ballini, Roberto,Petrini, Marino
, p. 336 - 337 (2007/10/02)
Carbonyl compounds were regenerated from corresponding Ethanediyl S,S-Acetals via equilibrium exchange with aqueous acetone, paraformaldehyde and Amberlyst 15, as acidic catalyst, at 80 deg C.
CHEMOSELECTIVITY IN MOLYBDENUM CATALYZED ALCOHOL AND ALDEHYDE OXIDATIONS
Trost, Barry M.,Masuyama, Yoshiro
, p. 173 - 176 (2007/10/02)
Hydrogen peroxide in the presence of (NH4)6Mo7O24*4H2O and potassium carbonate is a chemoselective method to oxidize secondary alcohols to ketones and to oxidize aldehydes to acids, the latter also accelerated by cerium chloride.
Steroids. Part 21. Photorearrangement of Steroidal Nitronate Salts and a N-Butyl Spiro-oxaziridine
Edge, Graham J.,Imam, Syed H.,Marples, Brian A.
, p. 2319 - 2326 (2007/10/02)
Irradiation, at 254 nm, of ethanol solutions of nitro-steroids in the presence of an excess of sodium ethoxide gave a range of products including hydroxamic acids, ketones, and alkenes possibly derived from the anions of the N-hydroxyoxaziridines.Alternatively, the ketones and hydroxamic acids may be derived from the anions of the hydroxy-nitroso compounds.The proportions of products depend on the ring size and stereochemistry and the photoreactions differ significantly from those observed for N-alkyl spiro-oxaziridines including a steroidal N-butyl spiro-oxaziridine.
Synthesis of new steroid haptens for radioimmunoassay. III. 15beta Carboxyethylmercaptosteroid bovine serum albumin conjugates. Specific antisera for radioimmunoassay.
Rao,Khan,Moore Jr.
, p. 171 - 184 (2007/10/10)
The synthesis of 15β carboxyethylmercapto 5α dihydrotestosterone, 15β carboxyethylmercapto 5α androstane 3β, 17β diol and 15β carboxyethylmercapto 5α androstane 3α, 17β diol and the preparation of their bovine serum albumin (BSA) conjugates are described.
