61949-57-3Relevant articles and documents
PROCESS FOR PREPARATION OF 7-DEHYDROCHOLESTEROL
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, (2015/11/27)
The invention discloses an improved cost-effective process for preparation of 7-Dehydrocholesterol of formula I with good yield and purity, comprising:a) epimerizing 7(alpha+beta) bromo protected cholesterol in presence of tetrabutyl ammonium bromide in toluene or a ketonic solvent or combinations thereof to obtain predominantly 7.alpha-bromo 3-protected cholesterol; b) Reacting 7.apha-bromo 3- protected cholesterol with substituted or unsubstituted thiophenol or its salts in presence of a liquor ammonia to obtain predominantly 7β-thiophenyl)-3-protected cholesterol; c) Oxidizing 7. beta. - thiophenyl 3-protected cholesterol in presence of Cumene hydrogen peroxide and Titanium tetraisopropoxide to obtain 7. beta. -phenyl sulfoxide 3-protected cholesterol; d) Converting 7. beta. -phenyl sulfoxide 3-protected cholesterol into 7-Dehydro 3-protected cholesterol in presence of base; e) purifying 7-Dehydro 3-protected cholesterol by suspending in a suitable organic solvent; and f) Deprotecting the 7-Dehydro 3-protected cholesterol by treating with alkali in presence of methanol to obtain 7-Dehydrocholesterol followed by purification of 7-Dehydrocholesterol from an organic solvent.
5,10:13,14-Disecosteroids: novel modified steroids containing 10- and 9-membered rings
Bjelakovi?, Mira S.,Krsti?, Natalija M.,Todorovi?, Nina,Kruni?, Aleksej,Tinant, Bernard,Dabovi?, Milan M.,Pavlovi?, Vladimir D.
scheme or table, p. 9557 - 9568 (2010/02/28)
In this paper a synthetic pathway to the modified 5,10:13,14-bisfragmentation cholestane derivatives 8-14 is described. The synthesis involves introduction of the 5α- and 14α-hydroxyl groups in the cholestane molecule and subsequent cleavage of the C(5)-C(10) bond in 5α,14α-dihydroxycholestan-3β-yl acetate (4) with the HgO/I2 reagent and the C(13)-C(14) bond in the stereoisomeric 14α-hydroxy-5,10-secosteroids 5 and 6 with the Pb(OAc)4/I2 reagent. Complete and unambiguous 1H and 13C NMR resonance assignments of the obtained secosteroids, as well as the solution conformations of their 10- and 9-membered rings were determined by extensive analysis of 1D and 2D NMR spectral data. The structures and the solid-state conformations of 5,10-secosteroids 5-7 were confirmed by X-ray analysis. All diseco-compounds have a novel 5,10:13,14-disecocholestane skeleton.
Synthesis of?oxysterols and?nitrogenous sterols with antileishmanial and?trypanocidal activities
Bazin, Marc-Antoine,Loiseau, Philippe M.,Bories, Christian,Letourneux, Yves,Rault, Sylvain,El Kihel, La?la
, p. 1109 - 1116 (2007/10/03)
Two sterol families have been synthesized: the first one is nitrogenous sterols containing amino, N-hydroxyimino or cyano group and the second one is oxysterols such as ketosterol and hydroxysterols. These compounds were then evaluated in vitro against Leishmania donovani promastigotes and Trypanosoma brucei brucei trypomastigotes. The most active compounds against L.?donovani promastigotes were 7β-aminomethylcholesterol and 7α,β-aminocholesterol (IC50 in a range from 1 to 3?μM, pentamidine: 2.8?μM). These compounds were active on intramacrophage amastigotes with IC50 of 1.3?μM. Such an activity justifies further in vivo antileishmanial evaluation. Against T. b. brucei, (24R,S)-24-hydroxy-24-methylcholesterol (MEC, 12.5?μM) was the most active compound from these series.
A Convenient Synthesis of Cholesta-1,5,7-trien-3β-ol
Tachibana, Yoji
, p. 3702 - 3704 (2007/10/02)
Cholesta-4,6-dien-3β-ol (4) was obtained selectively by the dehydrobromination of 7-bromocholesterol with a base in the presence of a catalytic amount of tetrabutylammonium bromide.The oxidation of 4 with 2,3-dichloro-5,6-dicyano-p-benzoquinone gave cholesta-1,4,6-trien-3-one (7).Treatment of 7 with isopropenyl acetate under acidic conditions afforded (3-acetoxy-1,3,5,7-cholestatetraene which was reduced with calcium borohydride to yield cholesta-1,5,7-triene-3β-ol (2).
