- 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 0037; 0038
(2019/07/16)
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- Zinc triflate catalyzed acylation of alcohols, phenols, and thiophenols
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An expedient procedure for the acylation of alcohols, phenols, and thiophenols using catalytic amount of Zn(OTf)2 is described. This procedure is highly suitable for industrial application due to use of less toxic metal as a part of catalyst, short reaction time at ambient temperature, without any racemization of chiral alcohols.
- Kumar, N. Uday,Reddy, B. Sudhakar,Reddy, V. Prabhakar,Bandichhor, Rakeshwar
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supporting information
p. 910 - 912
(2014/02/14)
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- Zinc triflate catalyzed acylation of alcohols, phenols, and thiophenols
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An expedient procedure for the acylation of alcohols, phenols, and thiophenols using catalytic amount of Zn(OTf)2 is described. This procedure is highly suitable for industrial application due to use of less toxic metal as a part of catalyst, short reaction time at ambient temperature, without any racemization of chiral alcohols.
- Uday Kumar,Sudhakar Reddy,Prabhakar Reddy,Bandichhor, Rakeshwar
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supporting information
p. 910 - 912
(2015/02/19)
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- The scope and limitations of the reaction of Δ5-steroids with mercury(II) trifluoroacetate
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The effect of the C-3 substituent on the reaction of androst-5-enes with mercury(II) trifluoroacetate in dichloromethane (modified Treibs oxidation) was investigated. 3β-Acyloxyandrost-5-en-17-ones gave 3β-acyloxy-6β- hydroxyandrost-4-en-17-ones accompanied by 3β-acyloxy-6- chloromercuriandrost-5-en-17-ones. 3β-Acetoxy-6β-trifluoroacetoxyandrost- 4-en-17-one and 3β-acetoxy-4β-trifluoroacetoxyandrost-5-en-17-one were revealed to be intermediates in the reaction. The formation of the chloromercury steroids indicated participation in the reaction by the solvent. With 3α-acetoxyandrost-5-en-17-one as substrate, a complete reversal in the product distribution was observed. 3β-Haloandrost-5-en-17- ones gave mainly products that reflected S(N)1 substitution of the halide. 3β-Hydroxy- and 3β-trifluoroacetoxyandrost-5-en-17-ones were formed. 3β- Methoxyandrost-5-en-17-one afforded in nearly identical yields androst-4- ene-3,17-dione, 3β-methoxy-6β-hydroxyandrost-4-en-17-one, 3β-methoxy-6- chloromercuriandrost-5-en-17-one and 6β-hydroxyandrost-4-ene-3,17-dione while androst-5-en-17-one yielded 3β,6β-dihydroxyandrost-4-en-17-one, androst-5-ene-7,17-dione and androst-4-ene-3,17-dione. The effects of solvent and other mercury salts on the reaction were also studied. Treibs oxidation was successful in chloroform, carbon tetrachloride, and dibromomethane, but not in other solvents tested. 3β-Acetoxy-6-bromomercuriandrost-5-en-17-one was obtained in dibromomethane. Replacement of the reagent by mercury(II) trichloroacetate altered the intermediates formed but not the products. Mercury(II) tribromoacetate was unreactive, however.
- Ruddock, Peter L.D.,Williams, David J.,Reese, Paul B.
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p. 650 - 664
(2007/10/03)
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- Factors Affecting the Facial Selectivity in the Hydroboration of Steroidal Δ5-Enes
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A comparison between the facial selectivity observed in the hydroboration of some androst-5-enes and B-norandrost-5-enes does not parallel the differences between the calculated force field energies of α- and β-cyclobutane models suggesting that in this case the facial selectivity is not determined by the four centre transition state but by the ease of formation of the initial ?-complexes between the alkene and the borane.
- Arantes, Simone F.,Hanson, James R.,Liman, Mansur D.,Manickavasagar, Revathy,Uyanik, Cavit
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p. 2381 - 2397
(2007/10/03)
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