111 research outputs found
Bis[3α,7α,12α-tris(4-nitrobenzoyloxy)-5β-cholan-24-yl] disulfide–ethyl acetate–n-hexane (4/4/1)
The crystal structure of the title compound, C90H100N6O24S2·C4H8O2·0.25C6H14, solved and refined against synchrotron diffraction data, contains two formula units in the asymmetric unit with the all-trans n-hexane molecule having half-occupancy and one of the ethyl acetate molecules disordered over two positions. The two symmetry-independent disulfide molecules are assembled by approximate face-to-face and face-to-edge interactions between their 4-nitrobenzoyloxy groups into an intertwined dimer having a double-helix-type structure. The centrally placed disulfide bridges in the two symmetry-independent molecules exhibit different helicity as shown by the C—S—S—C torsion angles of 71.0 (1) and −92.5 (1)°
Electrochemical oxidation of cholesterol
Indirect cholesterol electrochemical oxidation in the presence of various mediators leads to electrophilic addition to the double bond, oxidation at the allylic position, oxidation of the hydroxy group, or functionalization of the side chain. Recent studies have proven that direct electrochemical oxidation of cholesterol is also possible and affords different products depending on the reaction conditions
Some reactions of 16α,17α-oxido-steroids: a study related to the synthesis of the potent anti-tumor Saponin OSW-1 aglycone
One-Step Synthesis of Nitriles from Acids, Esters and Amides Using DIBAL-H and Ammonium Chloride
Two-step Synthesis of Solasodine Pivalate from Diosgenin Pivalate
A two-step synthesis of solasodine pivalate from diosgenin pivalate is described. The key transformation involves the reaction of diosgenin pivalate with benzyl carbamate (CbzNH2) promoted by TMSOTf. During the reaction the F-ring of the spiroketal moiety opens up with a simultaneous introduction of a Cbz-protected amino group in position 26. A one-pot deprotection of 26-amine with AcBr/BuOH followed by the N-cyclization affords solasodine pivalate in 45% overall yield.</jats:p
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