566-93-8Relevant academic research and scientific papers
Electrosynthesis of cholesta-4,6-dien-3-one from cholesterol on a laboratory synthetic scale
Hosokawa, Yu-Ya,Hakamata, Hideki,Murakami, Tomonori,Kusu, Fumiyo
, p. 129 - 132 (2010)
Cholesterol has been shown to be electrochemically oxidized at a carbon electrode to form cholesta-4,6-dien-3-one in acetonitrile [Hosokawa, Y. Y.; Hakamata, H.; Murakami, T.; Aoyagi, S.; Kuroda, M.; Mimaki, Y.; Itoh, A.; Morosawa, S.; Kusu, F. Electrochim. Acta, 2009, 54, 6412-6416]. To further expand on this reaction in the field of organic synthesis, the electrolysis conditions of cholesterol were optimized on a laboratory synthetic scale. Using a flow-through column electrolysis system, cholesta-4,6-dien-3-one was efficiently produced at the applied potential of 1.9 V versus Ag/AgCl with a flow rate of 2.5 mL/min, providing a green tool for the synthesis of cholesta-4,6-dien-3-one.
Platinum-Catalyzed α,β-Desaturation of Cyclic Ketones through Direct Metal–Enolate Formation
Chen, Ming,Dong, Guangbin
supporting information, p. 7956 - 7961 (2021/03/01)
The development of a platinum-catalyzed desaturation of cyclic ketones to their conjugated α,β-unsaturated counterparts is reported in this full article. A unique diene-platinum complex was identified to be an efficient catalyst, which enables direct metal-enolate formation. The reaction operates under mild conditions without using strong bases or acids. Good to excellent yields can be achieved for diverse and complex scaffolds. A wide range of functional groups, including those sensitive to acids, bases/nucleophiles, or palladium species, are tolerated, which represents a distinct feature from other known desaturation methods. Mechanistically, this platinum catalysis exhibits a fast and reversible α-deprotonation followed by a rate-determining β-hydrogen elimination process, which is different from the prior Pd-catalyzed desaturation method. Promising preliminary enantioselective desaturation using a chiral-diene-platinum complex has also been obtained.
Chemical synthesis of 7α-hydroxycholest-4-en-3-one, a biomarker for irritable bowel syndrome and bile acid malabsorption
Offei, Samuel D.,Arman, Hadi D.,Yoshimoto, Francis K.
, (2019/07/31)
7α-Hydroxy-cholest-4-en-3-one is a biomarker for bile acid loss, irritable bowel syndrome, and other diseases associated with defective bile acid biosynthesis. Furthermore, 7α-hydroxy-cholest-4-en-3-one is the physiological substrate for cytochrome P450 8B1 (P450 8B1 or CYP8B1), the oxysterol 12α-hydroxylase enzyme implicated in obesity and cardiovascular health. We report the chemical synthesis of this physiologically important oxysterol beginning with cholesterol. The key feature of this synthesis involves a regioselective C3-allylic oxidation of a 3-desoxy-Δ4-7α-formate steroid precursor to form 7α-formyloxy-cholest-4-en-3-one, which was saponified to yield 7α-hydroxy-cholest-4-en-3-one.
P -TsOH-Catalyzed one-pot transformation of di- and trihydroxy steroids towards diverse A/B-ring oxo-functionalization
Sarkar, Antara,Das, Jayanta,Ghosh, Pranab
, p. 9051 - 9060 (2017/08/29)
A solid support-mediated p-TsOH-catalyzed milder transformative protocol was developed to furnish diverse ring-A and/or ring-B oxo-functionalized steroids. To furnish interesting isomers involving the A/B-ring of biomolecules in a one-pot approach, only solid supports (and not solution!) were found to be effective. p-TsOH/SiO2-oxidation of 4β-hydroxycholesterol, the major oxysterol in human circulation, into a mixture of cholest-4-en-3-one, cholest-4-ene-3,6-dione, and 5α-cholestane-3,6-dione was the starting point for the investigations herein. The reaction protocol was optimized in detail, and efforts were carried out toward gaining an understanding of the mechanistic aspects favoring the solid support, and a possible synergetic catalytic system involving p-TsOH and SiO2 was expected to be a key part. Application of the novel methodology to 4β,7α-dihydroxy steroids resulted in the desired diverse ketosteroids through oxidation/oxidative dehydration, which generalized the process as a facile multi-oxo-functionalization steroidal transformation.
Semisynthesis and quantitative structure-activity relationship (QSAR) study of some cholesterol-based hydrazone derivatives as insecticidal agents
Yang, Chun,Shao, Yonghua,Zhi, Xiaoyan,Huan, Qu,Yu, Xiang,Yao, Xiaojun,Xu, Hui
supporting information, p. 4806 - 4812 (2013/09/02)
In continuation of our program aimed at the discovery and development of natural-product-based insecticidal agents, four series of novel cholesterol-based hydrazone derivatives were synthesized, and their insecticidal activity was tested against the pre-third-instar larvae of oriental armyworm, Mythimna separata (Walker) in vivo at 1 mg/mL. All the derivatives showed the better insecticidal activity than their precursor cholesterol. Quantitative structure-activity relationship (QSAR) model demonstrated that six descriptors such as RDF085v, Mor06u, Mor11u, Dv, HATS0v and H-046, are likely to influence the insecticidal activity of these compounds. Among them, two important ones are the Mor06u and RDF085v.
2-Iodoxybenzoic acid organosulfonates: Preparation, X-ray structure and reactivity of new, powerful hypervalent iodine(v) oxidants
Yusubov, Mekhman S.,Svitich, Dmitrii Yu.,Yoshimura, Akira,Nemykin, Victor N.,Zhdankin, Viktor V.
supporting information, p. 11269 - 11271 (2013/12/04)
New powerful hypervalent iodine(v) oxidants, tosylate and mesylate derivatives of 2-iodoxybenzoic acid (IBX), were prepared by the reaction of IBX with the corresponding sulfonic acids. Single crystal X-ray crystallography of the diacetate derivative of IBX-tosylate revealed an unusual heptacoordinated iodine geometry without any significant intermolecular secondary interactions.
A selective electrochemical method of glycosylation of 3β-hydroxy-Δ5-steroids
Morzycki, Jacek W.,?otowski, Zenon,Siergiejczyk, Leszek,Wa?ejko, Piotr,Witkowski, Stanis?aw,Kowalski, Jan,P?oszyn?ska, Jolanta,Sobkowiak, Andrzej
experimental part, p. 1051 - 1055 (2010/08/20)
A new electrochemical glycosylation method is presented. According to the method cholesterol and other 3β-hydroxy-Δ5-steroids can be selectively transformed to glycosides using non-activated sugars. The method is also useful for the synthesis of glycoconjugates with sugar linked to a steroid moiety by an ether bond.
Chemoselective reduction of 1,4,6-cholestatrien-3-one and 1,4,6-androstatriene-3,17-dione by various hydride reagents
Kim, Eunjeong,Ma, Eunsook
, p. 360 - 367 (2008/02/04)
The chemoselectivity of rigid cyclic α,β-unsaturated carbonyl group on the reducing agents was influenced by the ring size and steric factor. Cholesterol (cholest-5-en-3β-ol) and dehydroepiandrosterone (DHEA) were oxidized with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone to form 1,4,6-cholestatrien-3-one and 1,4,6-androstatriene-3,17-dione. They were reduced with NaBH4, lithium tri-sec-butylborohydride (l-Selectride), LiAlH4, 9-borabicyclo[3.3.1]nonane (9-BBN), lithium triethylborohydride (Super-hydride), and BH3·(CH3)2S in various conditions, respectively. Reduction of 1,4,6-cholestatrien-3-one and 1,4,6-androstatriene-3,17-dione by NaBH4 (4 equiv.) produced 4,6-cholestadien-3β-ol and 4,6-androstadiene-3β,17β-diol, respectively. Reduction by l-Selectride (12 equiv.) afforded 4,6-cholestadien-3α-ol and 4,6-androstadiene-3α,17β-diol, chemoselectively. Reaction with Super-hydride (12 equiv.) produced 4,6-cholestadien-3-one and 3-oxo-4,6-androstadien-17β-ol. Reduction of 1,4,6-cholestatrien-3-one by 9-BBN (14 equiv.) produced 1,4,6-cholestatrien-3α-ol, but 1,4,6-androstatriene-3,17-dione was not reacted with 9-BBN in the reaction conditions. Reaction of LiAlH4 (6 equiv.) formed 4,6-cholestadien-3β-ol and 3-oxo-1,4,6-androstatrien-17β-ol. Reduction of 1,4,6-cholestatrien-3-one by BH3·(CH3)2S (11 equiv.) gave cholestane as major compound and unlike reactivity of cholesterol, 1,4,6-androstatriene-3,17-dione by 8 equiv. of BH3·(CH3)2S formed 3-oxo-1,4,6-androstatrien-17β-ol. LiAlH4 and BH3·(CH3)2S showed relatively low chemoselectivity.
A convenient method for the preparation of Δ4,7-steroidal 3-ketones and Δ5,7 sterols
Giner, Jose-Luis,Zhao, Hui
, p. 605 - 609 (2007/10/03)
A method is described for the preparation of Δ4,7-steroidal ketones or Δ5,7-sterols from Δ5-sterols via the sequence Wettstein-Oppenauer oxidation, trifluoroacetylation to give the Δ2,4,6-enol ester, and acid catalyzed isomerization to the Δ3,5,7-enol ester, followed by acid hydrolysis, or sodium borohydride reduction, respectively.
π-Allyl-Palladium-Komplexe stabilisiert durch den tripodalen Sauerstoffliganden [(C5H5) Co{P( OMe) 2O}3]-II 1. Eliminierung statt C-C-Bindungsbildung bei der Reaktion mit resonanzstabilisierten Carbanionen 2
Domhoever, Bernd,Klaeui, Wolfgang
, p. 207 - 212 (2007/10/03)
The reaction of the complexes [LOMePd(propenyl] (1) and [LOMePd(2-methyl-propenyl] (2) (L-OMe= [(C5H5)Co{P(OMe)2O}3]-) with sodium malonate results in the formation of the anticipated C-C coupling products (2-R-C3H5)CH(CO2Et)2 while [LOMePd{4-6-η-(3-oxo-cholestenyl)}] (4) and [LOMePd{4-6-η-(cholestenyl)}] (5) react with eliminination to give the corresponding cholestadienes. With sodium 2-acetylcyclopentanoate (Na acp), ligand substitution takes place in the reaction with 1-3 (3 = [LOMePd(2-tbutyl-propenyl)]) to give complexes of the type [(2-R-propenyl)Pd(acp)]. Their stability depends on the substituent of the allyl group. While [(propenyl)Pd(acp)] decomposes at room temperature, [(2-tbutyl-propenyl)Pd(acp)] and [(2-methyl-propenyl)Pd(acp)] are air stable compounds which could be isolated.
