18462-31-2Relevant academic research and scientific papers
Recycling method of positional isomer in preparation of 3beta-acetoxy-5alpha-chloro-6beta-hydroxyandrost-17-one
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Paragraph 0037; 0038, (2019/07/16)
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.
Zinc triflate catalyzed acylation of alcohols, phenols, and thiophenols
Kumar, N. Uday,Reddy, B. Sudhakar,Reddy, V. Prabhakar,Bandichhor, Rakeshwar
supporting information, p. 910 - 912 (2014/02/14)
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.
Zinc triflate catalyzed acylation of alcohols, phenols, and thiophenols
Uday Kumar,Sudhakar Reddy,Prabhakar Reddy,Bandichhor, Rakeshwar
supporting information, p. 910 - 912 (2015/02/19)
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.
Iminyl, Amidyl, and Carbamyl Radicals from O-Benzoyl Oximes and O-Benzoyl Hydroxamic Acid Derivatives.
Boivin, Jean,Callier-Dublanchet, Anne-Claude,Quiclet-Sire, Beatrice,Schiano, Anne-Marie,Zard, Samir Z.
, p. 6517 - 6528 (2007/10/02)
Oxime benzoates and O-benzoyl hydroxamic acid derivatives react with tributylstannane in the presence of AIBN to give iminyl, amidyl, and carbamyl radicals which can be captured by an internal olefin.
Iminyl radicals by stannane mediated cleavage of oxime esters
Boivin, Jean,Schiano, Anne-Marie,Zard, Samir Z.
, p. 249 - 252 (2007/10/02)
Despite the explosive growth in the use of radical reactions which has swept organic synthesis in the past few years, nitrogen centred radicals and iminyls in particular have not yet attracted the attention they deserve This can be traced to a large extent to a lack of convenient and mild methods for generating such species. As part of a general study of the reactivity and synthetic potential of iminyls, we recently showed that the reaction of sulfenimines with tributystannane or the Barton decarboxylation of O-carboxymethyl oximes represented useful routes to these intermediates. Another promising approach, still in its preliminary stages however, involved the reduction of oxime esters with nickel powder in acetic acid. in this Letter, we describe yet another method based on the cleavage of oxime benzoates with tin centered radicals.
o-Nitrophenylethylene glycol as photoremovable protective group for aldehydes and ketones: syntheses, scope, and limitations
Gravel, D.,Herbert, J.,Thoraval, D.
, p. 400 - 410 (2007/10/02)
The preparation of o-nitophenylethylene glycol is described along with its application as a photolabile protective group for aldehydes and ketones.Formation of the acetals and ketals is achieved in good to high yields in the usual manner and deprotection is carried out in fair to high yield, by photolysis at 350 nm in an inert solvent such as benzene.Because of the particular nature of the present protective group, its stability to basic and acidic conditions has been examined and is reported to complete the scope and limitations aspect.From a mechanistic point of view, the isolation and characterisation of o-nitroso-α-hydroxyacetophenone as the spent reagent demonstrates a mechanistic link with the known o-nitrobenzaeldehyde to o-nitrobenzoic acid photorearrangement.
Photo-induced Transformations. Part 44. Formation of Lactams in the Photolysis of Some Steroidal Acetylhydrazones in the Presence of Oxygen
Suginome, Hiroshi,Uchida, Tsutomu
, p. 1356 - 1364 (2007/10/02)
Irradiation of 3α-acetoxy-5α-androstan-17-one acetylhydrazone (3) or 3β-acetoxyandrost-5-en-17-one acetylhydrazone (5) in dioxan in the presence of oxygen afforded 17-oxo-17a-aza-D-homosteroid and its 13α-isomer , while when oxygen was excluded none of these lactams were formed under otherwise similar conditions. 5α-Cholestan-6-one acetylhydrazone (20) under similar conditions also afforded very low yields of 6-aza-D-homo-5α-cholestan-7-one (21) and 7-aza-B-homo-5α-cholestan-6-one (22) upon photolysis.In contrast with the acetylhydrazones, the corresponding hydrazone (2), upon photolysis in dioxan without the exclusion of oxygen, afforded the corresponding azine (13) without any accompanying lactams .There is a distinct difference in behaviour between the hydrazones and the N-acetyl derivatives towards oxygen under irradiation.Although as yet no definite conclusion can be drawn on the mechanism of lactam formation, some plausible paths are discussed.
