83872-56-4Relevant academic research and scientific papers
Method for preparing 2-methyl-4-(benzenesulfonyl)-2-butanol
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Paragraph 0008; 0013-0016, (2021/06/09)
The invention provides a method for preparing 2-methyl-4-(benzenesulfonyl)-2-butanol. According to the method, sodium benzenesulfinate and halogenated pentanol (X-C5-OH) are used as raw materials and react with each other under the action of a catalyst, namely tetrabutylammonium bromide, so a target product can be obtained. The method provided by the invention has the advantages of easily available raw materials, mild reaction conditions, simple post-treatment, easy realization of industrialization and the like, and is a good method for synthesizing 2-methyl-4-(benzenesulfonyl)-2-butanol.
Preparation method of a 25-hydroxy vitamin D3 intermediate
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Paragraph 0071; 0076-0078; 0079; 0084-0086; 0087; 0092-0095, (2020/04/29)
The invention discloses a preparation method of a 25-hydroxy vitamin D3 intermediate, wherein the 25-hydroxy vitamin D3 intermediate is 2-methyl-4-(phenylsulfonyl)-2-butanol, and is prepared from 3-methyl-3-butanol-p-toluenesulfonate, a halide and sodium
Eosin Y as a Direct Hydrogen-Atom Transfer Photocatalyst for the Functionalization of C?H Bonds
Fan, Xuan-Zi,Rong, Jia-Wei,Wu, Hao-Lin,Zhou, Quan,Deng, Hong-Ping,Da Tan, Jin,Xue, Cheng-Wen,Wu, Li-Zhu,Tao, Hai-Rong,Wu, Jie
supporting information, p. 8514 - 8518 (2018/07/14)
Eosin Y, a well-known economical alternative to metal catalysts in visible-light-driven single-electron transfer-based organic transformations, can behave as an effective direct hydrogen-atom transfer catalyst for C?H activation. Using the alkylation of C?H bonds with electron-deficient alkenes as a model study revealed an extremely broad substrate scope, enabling easy access to a variety of important synthons. This eosin Y-based photocatalytic hydrogen-atom transfer strategy is promising for diverse functionalization of a wide range of native C?H bonds in a green and sustainable manner.
Visible-Light-Promoted Remote C-H Functionalization of o-Diazoniaphenyl Alkyl Sulfones
Du, Shaofu,Kimball, Elizabeth Ann,Ragains, Justin R.
supporting information, p. 5553 - 5556 (2017/10/25)
Visible-light irradiation of ortho-diazoniaphenyl alkyl sulfones in the presence of Ru(bpy)32+ results in remote Csp3-H functionalization. Key mechanistic steps in these processes involve intramolecular hydrogen atom transfer from Csp3-H bonds to aryl radicals to generate alkyl/benzyl radicals. Subsequent polar crossover occurs by single-electron oxidation of the alkyl/benzyl radicals to carbenium ions that then intercept nucleophiles. We have developed remote hydroxylations, etherifications, an amidation, and C-C bond formation processes using this strategy.
Efficient synthesis and biological evaluation of all A-ring diastereomers of 1α,25-dihydroxyvitamin D3 and its 20-epimer
Fujishima, Toshie,Konno, Katsuhiro,Nakagawa, Kimie,Kurobe, Mayuko,Okano, Toshio,Takayama, Hiroaki
, p. 123 - 134 (2007/10/03)
An improved synthesis of the diastereomers of 1α,25-dihydroxyvitamin D3 (1) was accomplished utilizing our practical route to the A-ring synthon. We applied this procedure to synthesize for the first time all possible A- ring diastereomers of 20-epi-1α,25-dihydroxyvitamin D3 (2). Ten-step conversion of 1-(4-methoxyphenoxy)but-3-ene (6), including enantiomeric introduction of the C-3 hydroxyl group to the olefin by the Sharpless asymmetric dihydroxylation, provided all four possible stereoisomers of A- ring enynes (3), i.e., (3R,5R)-, (3R,5S)-, (3S,5R)- and (3S,5S)-bis[(tert- butyldimethylsilyl)oxy]oct-1-en-7-yne, in good overall yield. Palladium- catalyzed cross-coupling of the A-ring synthon with the 20-epi CD-ring portion (5), (E)-(20S)-de-A,B-8-(bromomethylene)cholestan-25-ol, followed by deprotection, afforded the requisite diastereomers of 20-epi-1α,25- dihydroxyvitamin D3 (2). The biological profiles of the synthesized stereoisomers were assessed in terms of affinities for vitamin D receptor (VDR) and vitamin D binding protein (DBP), HL-60 cell differentiation- inducing activity and in vivo calcium-regulating potency in comparison with the natural hormone. (C) 2000 Elsevier Science Ltd.
Vitamin D analogues
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, (2008/06/13)
STR1 The present invention relates to compounds of formula (I), in which formula, n is 0 or 1, m is 0 or an integer from 1-7, R1 and R2 (which may be the same or different) stand for hydrogen or C1 l-C8 -hydroca
Convenient synthesis of 1α,25-dihydroxyvitamin D3 from vitamin D2
Takahashi,Sakakibara
, p. 2494 - 2499 (2007/10/02)
(1S,6R)-1-Acetoxy-6-(1,3-benzodithiol-2-yloxy)-3,5-cyclovitamin D2 (7) was synthesized from vitamin D2 by five steps. The new compound 7 was ozonized regioselectively and subsequently reduced, leading to (7E)-(1S,3S,5R,6R)-1-acetoxy-6-(1,3-benzodithiol-2-yloxy)-3,5-cyclo-9, 10-seco-23,24-dinor-7,10(19)-choladien-22-ol (11). The alcohol 11 obtained as a key intermediate was tosylated, iodinated, and coupled with 2-methyl-4-phenylsulfonyl-2-(tetrahydropyranyloxy)butane to give (1S,6R)-1-hydroxy-6-(1,3-benzodithiol-2-yloxy)-23-phenylsulfonyl-25-te trahydropyranyloxy-3,5-cyclovitamin D3 (16). By desulfonylation and hydrolysis of the compound 16 1α,25-dihydroxyvitamin D3 was obtained selectively.
Generation of hydroxyl radicals from 1-hydroxypyridine-2(1H)-thione and their application to organic synthesis
Boivin, J.,Crepon, E.,Zard, S. Z.
, p. 145 - 150 (2007/10/02)
Upon irradiation with visible light N-hydroxypyridine-2-thione 1 gives rise to hydroxyl radicals which can be used in radical chain reactions involving selective hydrogen abstraction as the key-step. Key Words: N-hydroxypyridine-2-thione / hydroxyl radicals
N-HYDROXY-2-PYRIDINETHIONE: A MILD AND CONVENIENT SOURCE OF HYDROXYL RADICALS
Boivin, Jean,Crepon, Elisabeth,Zard, Samir Z.
, p. 6869 - 6872 (2007/10/02)
N-Hydroxy-2-thiopyridone gives hydroxyl radicals on irradiationm with visible light and these can be incorporated in useful radical chain processes involving hydrogen abstraction.
