Results 91 to 100 of about 282 (137)
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Acta Crystallographica Section C Crystal Structure Communications, 1996
The crystal structure of the title compound, naphtho[2,3-b]cholestane, C 35 H 50 , is composed of independent molecules with normal molecular dimensions and no unusual contacts shorter than van der Waals distances.
M. Parvez +3 more
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The crystal structure of the title compound, naphtho[2,3-b]cholestane, C 35 H 50 , is composed of independent molecules with normal molecular dimensions and no unusual contacts shorter than van der Waals distances.
M. Parvez +3 more
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Australian Journal of Chemistry, 1983
Chlorination of Sa- and 5ß-cholestan-3-one (l) and (7) proceeds sequentially to give the a-monochloro (2) and (8), a,a-dichloro (3) and (9), and a, a, a'-trichloro (4) and (10) derivatives; the nature of the product mainly depends on the reaction conditions.
M Kuniyoshi, Y Satoh
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Chlorination of Sa- and 5ß-cholestan-3-one (l) and (7) proceeds sequentially to give the a-monochloro (2) and (8), a,a-dichloro (3) and (9), and a, a, a'-trichloro (4) and (10) derivatives; the nature of the product mainly depends on the reaction conditions.
M Kuniyoshi, Y Satoh
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Two‐photon‐induced fluorescence of cholestane
Biospectroscopy, 1996Cholestane is a fully saturated alkane with a structure analogous to cholesterol. We observed fluorescence emission from cholestane with a maximum near 235 nm when excited with picosecond laser pulses at 298 nm. The emission intensity of cholestane was found to depend on the square of the laser power, indicating the biphotonic process of two-photon ...
Rezik A. Agbaria +3 more
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Cholestane rhamnosides from the bulbs of Ornithogalum saundersiae
Phytochemistry, 1999Phytochemical examination of the bulbs of Ornithogalum saundersiae yielded six cholestane rhamnosides, two of which had previously been isolated from the same plant material. However, detailed spectroscopic analysis of the aglycone led us to revise the configuration of the C-11 hydroxyl group of the latter two and reassign their structures as (22S ...
M, Kuroda, Y, Mimaki, Y, Sashida
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Synthese der 2,5‐Diole des A‐nor‐5α‐Cholestans und A‐nor‐5β‐Cholestans
Helvetica Chimica Acta, 1967AbstractTreatment of A‐nor‐Δ3(5)‐cholestene‐2‐one (1) with alkaline hydrogen peroxide gave 3β,5‐epoxy‐A‐nor‐cholestane‐2‐one (2) and the epoxylactone 3 (BAEYER‐VILLIGER reaction). LiAlH4‐reduction of 2 yielded A‐nor‐5β‐cholestane‐2β,5‐diol(4) (main product) and A‐nor‐5β‐cholestane‐2α,5‐diol (5).
R. Heckendorn, Ch. Tamm
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Collection of Czechoslovak Chemical Communications, 1980
The synthesis and mass spectrometric behaviour of a series of oxygen-bridged α-cholestans and B-homo-5α-cholestans I-X are described. The differences in fragmentation patterns of these compounds are discussed in dependence on the position of the oxygen bridge, position and configuration of additional substituents and conformation of the A and B rings ...
František Tureček, Pavel Kočovský
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The synthesis and mass spectrometric behaviour of a series of oxygen-bridged α-cholestans and B-homo-5α-cholestans I-X are described. The differences in fragmentation patterns of these compounds are discussed in dependence on the position of the oxygen bridge, position and configuration of additional substituents and conformation of the A and B rings ...
František Tureček, Pavel Kočovský
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Reaction of Chlorotrimethylsilane with Some Cholestane Derivatives
Synthetic Communications, 1981Abstract Recent publications1–4 have highlighted diverse utility of chlorotrimethylsilane (C1Me3Si) as an important reagent for organic synthesis. This reagent can be used either directly or in combination with a suitable metal. The versatile nature of chlorotrimethylsilane in chemical transformations prompted us to carry out the reaction of some ...
Mubarak Husain, Haseem Hasan Khan
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The contraction of ring a in 5α-cholestane derivatives
Tetrahedron, 1960Abstract The β-keto-ester which is obtained by Dieckmann cyclization of the dimethyl ester (I) of the dicarboxylic acid obtained by oxidative opening of ring A in 5α-cholestan-3-one and related compounds has been shown to have the structure IIa, by its degradation, via the unsaturated acid (Va), to A-nor-5β-cholestan-3-one (VI) and to the dimethyl ...
B. Fuchs, H.J.E. Loewenthal
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ChemInform Abstract: 2‐HETERO‐CHOLESTANE
Chemischer Informationsdienst. Organische Chemie, 1971AbstractDas Cholestenon (I) gibt bei Reaktion mit K‐permanganat/Na‐perjodat die Dicarbonsäure (II), deren Dimethylester durch Reduktion mit Li‐alanat in das Diol (IIIa) übergeführt wird.
Y. KASHMAN, E. D. KAUFMAN
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Steroids. Part XXXVIII. 5-Chloro-5α-cholestane
J. Chem. Soc., Perkin Trans. 1, 1975The formation of 5-chloro-5α-cholestane from cholest-5-ene and hydrogen chloride in ether–ethanol at 25 °C appears to be accompanied by production of an unidentified chloro-5ξ-cholestane; 5-chloro-5β-cholestane could not be isolated.
C W, Shoppee, R D, Lundberg
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