Preparation of Oxysterols by C–H Oxidation of Dibromocholestane with Ru(Bpga) Catalyst |
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| Authors: | Yui Fujii Makoto Yoritate Kana Makino Kazunobu Igawa Daiki Takeda Daiki Doiuchi Katsuhiko Tomooka Tatsuya Uchida Go Hirai |
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| Institution: | 1.Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Fukuoka, Japan; (Y.F.); (M.Y.); (K.M.); (D.T.);2.Institute for Materials Chemistry and Engineering, Integrated Research Consortium on Chemical Sciences (IRCCS), Kyushu University, Kasuga 816-8580, Fukuoka, Japan; (K.I.); (K.T.);3.Department of Chemistry, Graduate School of Science, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Fukuoka, Japan; (D.D.); (T.U.) |
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| Abstract: | Seven mono- and dihydroxycholesterols were prepared by direct C–H oxidation of the cholestane skeleton with a recently developed Ru(Bpga) catalyst (Ru(Bpga) = RuCl (bpga) (PPh3)] Cl; bpga = 2-(bis(pyridin-2-ylmethyl)amino)-N-(2,6-dimethylphenyl)acetamide)). Due to the high selectivity of the Ru(Bpga) complex for tertiary C–H, the reaction afforded a mixture of 25-, 20-, 17-, and 14-oxygenated cholesterols that could be easily separated by high-performance liquid chromatography. These results suggest that late-stage C–H oxidation could be a viable strategy for preparing candidate metabolites of biologically important molecules. |
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| Keywords: | cholesterol oxysterol C– H oxidation Ru (bpga) 25-hydroxycholesterol dihydroxycholesterol |
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