16732-86-8Relevant academic research and scientific papers
REDUCTIVE REMOVAL OF ALLYLIC FUNCTIONAL GROUPS BY NICKEL BORIDE
Sarma, D. N.,Sharma, R. P.
, p. 2581 - 2584 (1985)
Reductive removal of an allylic functional group proceeds most easily and efficiently with nickel boride as the bond being cleaved becomes a better leaving group ( e.g.OCH3OHOSiMe3OCOCH3OCOCF3 )
Syntheses and CD Studies of New Cholesteno- and -pyrimidines
Hasan, Mashooda,Rashid, Naghmana,Khan, Khalid Mohammed,Perveen, Shahnaz,Snatzke, Guenther,et al.
, p. 1871 - 1876 (2007/10/03)
The syntheses of 5α- and 5β-cholest-3-enopyrimidines (7) and (7') could be achieved by using the hydroxymethylene derivative of cholestan-4-one (5) prepared from cholesterol (1).Their 2'-derivatives 7a-7d and 7'a-7'c were also synthesized. 5α-Cholest-6-enopyrimidine (13) was prepared by the reaction of 5α-cholestan-7-one (12) with tris(formylamino)methane.The CD spectra exhibit at least three Cotton effects between 300 and 210 nm, a first CD band around 290, a second one around 260, and a third one around 220 nm.An earlier developed quadrant rule can be applied to the determination of the sign of the first CD band, while the suggested helicity rule allows prediction of the third CD band. - Keywords: Cholestenopyrimidines / Circular dichroism / Quadrant rule of cholestenopyrimidines
Dephosphorylation of Cyano Diethyl Phosphates by Reduction with Lithium-Liquid Ammonia: An Efficient Method for Conversion of Carbonyl Compounds into Nitriles
Yoneda, Ryuji,Osaki, Takahiro,Harusawa, Shinya,Kurihara, Takushi
, p. 607 - 610 (2007/10/02)
Cyano diethyl phosphate derivatives of aromatic carbonyl compounds and α,β-unsaturated ketones were successively dephosphorylated by reduction with lithium in liquid ammonia followed by treatment with isoprene or alkyl halides to give β,γ-unsaturated nitriles or α-alkyl-β,γ-unsaturated nitriles in moderate to good yields.
Reductive Deoxygenation of α,β-Unsatured Ketones via Cyanophosphates by Lithium in Liquid Ammonia
Yoneda, Ryuji,Osaki, Hirotaka,Harusawa, Shinya,Kurihara, Takushi
, p. 2817 - 2818 (2007/10/02)
A new method for deoxygenation of α,β-unsatured ketones via cyanophosphates by lithium metal in liquid ammonia is described
Acid-catalysed Rearrangements of Steroid Alkenes. Part 2. A Re-investigation of the Backbone Rearrangement of Cholest-5-ene
Peakman, Torren M.,Ellis, Karen,Maxwell, James R.
, p. 1071 - 1076 (2007/10/02)
Backbone rearrangement of cholest-5-ene (1) with boron trifluoride-diethyl ether gives, in addition to the well known diacholest-13(17)-enes (4a,b), their 10β counterparts (6a,b) as minor products.With anhydrous toluene-p-sulphonic acid-acetic acid, additional products include components also isomeric at C-10 and C-20 and having a spiro C/D ring junction.A proposed scheme for the rearrangement is given.
NICKEL BORIDE REDUCTIVE CLEAVAGE OF ALLYLIC TRIMETHYLSILYL ETHERS
Sarma, D. N.,Sharma, R. P.
, p. 371 - 372 (2007/10/02)
Nickel boride reductive cleavage of allylic trimethylsilyl ethers yielding alkenes is described.
Stereochemistry and Regiochemistry of Electron Impact, Photolytically, and Thermally Induced Eliminations from 5α-Cholestanyl Acetates
Valente, C.,Eadon, G.
, p. 44 - 51 (2007/10/02)
Deuterium-labeled compounds were used to define the sterochemistry and regiochemistry of the electron impact induced eliminations of acetic acid from 5α-cholestanyl 3α-acetate, 4α-acetate, and 6α-acetate.Comparison of the electron impact induced eliminations to the pyrolysis and to the photolysis of the corresponding phenylacetates confirmed that the mass spectral elimination was a stepwise process proceeding through the stable chair conformation of the steroid's cyclohexyl ring.The equatorially oriented 4α- and 6α-acetates fragmented with predominant loss of asecondary trans-equatorial hydrogen, rather than the tertiary cis-axial hydrogen, despite the a priori greater migratory aptitude of tertiary hydrogens.The electron impact induced fragmentation of the 3α-acetate occured with predominant loss of a C-4 hydrogen; in contrast, the photolysis of the corresponding 3α-phenylacetate results in loss of a C-2 hydrogen.This results can be attributed to the reversibility of the photolytically induced hydrogen-abstraction step.
SYNTHESIS OF STEROIDAL DITHIOLANES. REACTION OF ETHANEDITHIOL WITH α,β-UNSATURATED STEROIDAL KETONES
Shamsuzzaman, Shafiullah,Khan, B. Z.
, p. 25 - 28 (2007/10/02)
The reaction of cholest-5-en-7-one (1) with 1,2-ethanethiol (BF3-etherate as catalysts) provided cholest-5-en-7-one ethylene thioketal (5).Under similar reaction conditions the ketones 2, 3 and 4 gave thioketals 6, 7 and 8, respectively.These thioketals (5, 6, 7 and 8) on desulfurization with Raney nickel afforded compounds 9, 10, 11 and 12, respectively.The structures of these compounds were established on the basis of their spectral properties, chemical transformations and comparison with authentic samples.
DIRECT CONVERSION OF OXIRANES TO ALKENES BY CHLOROTRIMETHYLSILANE AND SODIUM IODIDE
Caputo, Romualdo,Mangoni, Lorenzo,Neri, Orsola,Palumbo, Giovanni
, p. 3551 - 3552 (2007/10/02)
Smooth and quantitative conversion of oxiranes to alkenes is achieved by treatment with in situ generated iodotrimethylsilane.
Steroids. Part 39. 5-Chloro-5β-cholestane
Shoppee, Charles W.,Hart, Reinhold J.,Howden, Merlin E. H.
, p. 1904 - 1908 (2007/10/02)
The isolation and properties of 5-chloro-5β-cholestane are described.
