643758-93-4Relevant academic research and scientific papers
Regioselective oxyfunctionalization of unactivated carbons in steroids by a model of cytochrome P-450: Osmiumporphyrin complex/tert-butyl hydroperoxide system
Iida, Takashi,Ogawa, Shoujiro,Hosoi, Keiji,Makino, Mitsuko,Fujimoto, Yasuo,Goto, Takaaki,Mano, Nariyasu,Goto, Junichi,Hofmann, Alan F.
, p. 823 - 830 (2007/10/03)
(Chemical Equation Presented) tert-Butyl hydroperoxide catalyzed by (5,10,15,20-tetramesitylporphyrinate) osmium(II) carbonyl [Os(TMP)CO] complex was found to be a highly efficient versatile oxidant for C-H carbons in steroid substrates. When reacted with representative steroids with an estrane, pregnane, 5β-cholane, or 5α-cholestane structure, regioselective oxyfunctionalization and/or oxidative degradation occurred to give a variety of novel and uncommon derivatives in one step.
The remote-oxyfunctionalization of unactivated carbons in (5β)-3-oxobile acids by 2,6-dichloropyridine N-oxide catalyzed by ruthenium-porphyrin and HBr: A direct lactonization at C-20
Ogawa, Shoujiro,Iida, Takashi,Goto, Takaaki,Mano, Nariyasu,Goto, Junichi,Nambara, Toshio
, p. 1013 - 1018 (2007/10/03)
Remote-oxyfunctionalization induced by 2,6-dichloropyridine N-oxide (DCP N-oxide) as an oxygen donor and a (5,10,15,20-tetramesitylporphyrinate) ruthenium(n) carbonyl complex (Ru-porphyrin) and HBr as catalysts was examined for a series of methyl ester-peracetylated derivatives of (5β)-3-oxobile acids. Using the DCP-N-oxide/Ru-porphyrin/HBr system, 5β-hydroxylation predominated for the substrates having a 12-acetoxyl substituent due to steric hindrance, but the presence of a 7-acetoxyl substituent decreased the reactivity of the 5β-position allowing for the competitive (20S)-20- oxyfunctionalization, subject to electronic constraints. A variety of novel 5β-hydroxylation and (20S)-24,20-γ-lactonization products, as well as their double-oxyfunctionalization and dehydration products, were obtained in one-step. The alkaline hydrolysis of the γ-lactones gave the corresponding stereoselective (20S)-20-hydroxy-carboxylic acids.
