- Recycling method of positional isomer in preparation of 3beta-acetoxy-5alpha-chloro-6beta-hydroxyandrost-17-one
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The invention discloses a recycling method for forming 3beta-acetoxyandrost-5-en-17-one by performing a cyclization elimination reaction by utilizing solid waste 3beta-acetoxy-6beta-chloro-5alpha-hydroxyandrost-17-one obtained in the process of an addition reaction of preparing 3beta-acetoxy-5alpha-chloro-6beta-hydroxyandrost-17-one from 3beta-acetyloxyandrost-5-en-17-one as a raw material, and performing a reduction elimination reaction. The method provided by the invention can effectively recover and reuse the by-product obtained in the preparation process of the 3beta-acetoxy-5alpha-chloro-6beta-hydroxyandrost-17-one, and the synthetic method is simple and convenient to operate, has mild reaction conditions, is environmentally friendly, and reduces the production costs of preparing the3beta-acetoxy-5alpha-chloro-6beta-hydroxyandrost-17-one from the 3beta-acetyloxyandrost-5-en-17-one.
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Paragraph 0034; 0035
(2019/07/16)
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- Highly stereoselective epoxidation with H2O2 catalyzed by electron-rich aminopyridine manganese catalysts
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Fast, efficient, and highly stereoselective epoxidation with H 2O2 is reached by manganese coordination complexes with e-rich aminopyridine tetradentate ligands. It is shown that the electronic properties of these catalysts vary systematically with the stereoselectivity of the O-atom transfer event and exert fine control over the activation of hydrogen peroxide, reducing the amount of carboxylic acid co-catalyst necessary for efficient operation.
- Cusso, Olaf,Garcia-Bosch, Isaac,Font, David,Ribas, Xavi,Lloret-Fillol, Julio,Costas, Miquel
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supporting information
p. 6158 - 6161
(2014/01/17)
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- Highly selective lipase-mediated discrimination of diastereomeric 5,6-epoxysteroids
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Stereoisomerically pure 3β-hydroxy-5,6-epoxysteroids were obtained by combining selective chemical methods for α- and β-epoxidation of Δ5-unsaturated steroids with enzymatic stereoselective esterification of the 3β-hydroxyl group. 5β,6β-Epoxy-3β- hydroxysteroids were efficiently acylated by Novozym 435 and lipase AK, whereas 5α,6α-epoxy-3β-hydroxysteroids were good substrates for Candida rugosa lipase. Mild enzymatic deacylation of the 3β-acetoxy group in the presence of the epoxy functionality was also accomplished by C. rugosa lipase-mediated hydrolysis.
- Cruz Silva, M. Manuel,Riva, Sergio,Sa E Melo, M. Luisa
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p. 1173 - 1179
(2007/10/03)
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- The Stereochemistry of Epoxidation of Δ5-Steroids with Sodium Perborate and Potassium Permanganate
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Sodium perborate, with potassium permanganate as a catalyst, has been shown to be a novel reagent for the epoxidation of steroidal 5-enes with the attack occurring predominantly on the β-face.
- Hanson, James R.,Terry, Nicolas,Uyanik, Cavit
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- The Stereochemistry of Oxidation of Some B-Norsteroids
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The oxidation of ring B of some B-norsteroids is shown to have a different stereochemistry when compared to the same reactions in the normal six-membered series and it is suggested that caution should be exercised in drawing general stereochemical conclusions solely on evidence from the six-membered series.
- Hanson, James R.,Manickavasagar, Revathy,Thangavelu, Vasuki
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p. 3245 - 3260
(2007/10/03)
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- Stereoselective 7α-hydroxylation of 3β-acetoxy-Δ5-steroids by Fe(PA)3/H2O2/MeCN
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Stereoselective 7α-hydroxylation reaction of Δ5-steroids by a Fe(PA; picolinate)3/H2O2/MeCN system is presented. The 7α-hydroxylation reactions were achieved in 33-40% yields by addition of 30%-H2O2 to a solution of 3β-acetoxy-Δ5-steroids 1a-1d and a crystalline of Fe(PA)3 in MeCN.
- Kotani, Eiichi,Takeya, Tetsuya,Egawa, Hirotaka,Tobinaga, Seisho
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p. 750 - 752
(2007/10/03)
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- THE OXIDATION OF A STEROIDAL BROMOHYDRIN REVISITED
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A comparative study was made of the reactions of 5-bromo-3β,6β-dihydroxy-5α-androstan-17-one 3-acetate (1) with lead tetraacetate alone and in the presence of iodine in both high intensity visible light and in total darkness using a variety of solvents.Markedly different product profiles were obtained under the different reaction conditions, making our results of both practical importance and theoretical interest.
- Jennings, Bojan Hamlin,Yelle, Lauren Marie
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