- A route to the 9,10-secosteroid astrogorgiadiol featuring a key sp 2-sp3 Suzuki type cross-coupling
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The described semi-synthetic route differs from the previously published approaches by an original C-7-C-8 disconnection. The kinetic enol triflate of Grundmann ketone was chosen as the CD-ring platform on which to couple an A-ring synthon via a challengi
- Médard, Guillaume
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p. 186 - 196
(2014/01/06)
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- Synthesis of (-)-astrogorgiadiol
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Astrogorgiadiol is a naturally occurring Vitamin D analogue that, in cell culture, downregulates the production of the cytokine osteopontin (OPN). OPN has been implicated in virulent asthma, and OPN knockout mice do not develop osteoporosis. As we have pursued whole animal studies with astrogorgiadiol, we have increased the scale of the synthesis. We report an improved preparation of the A-ring synthon and the scale-up of the diasteromerically pure D-ring/sidechain chiron.
- Taber, Douglass F.,Raciti, David M.
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p. 10229 - 10233
(2012/02/03)
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- Collisionally induced dissociation in the study of A-ring hydroxylated vitamin D type compounds
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Colllslonally Induced dissociation (CID) is often used to determine the structure of ions based on comparison with the CID spectra of known ions. The latter are generated from Judiciously selected compounds taking into account basic principles of Ion chemistry. We report here on the use of this approach toward determination of the site of A-ring hydroxylation of vitamin D. Although not Intrinsically an aromatic compound, vitamin D gives rise in its mass spectrum to an aromatic methytstyryl cation at mlz 118. A-ring hydroxylated metabolites of vitamin D would thus Incorporate the extra OH group on the ion at mlz 118, shifting it to mlz 134. The position of substitution of the extra OH group on a metabolite could then be ascertained by comparing the CID spectrum of its mlz 134 fragment to those of the four possible (hydroxymethyl)styryl cations generated from synthesized authentic compounds. Because of their propensity to polymerize, these cations were generated in situ via the McLafferty rearrangement of the corresponding (hydroxyphenyl)ethanols. For optimum differentiation of Isomeric Ions, preparation of permethylated derivatives of vitamin D was necessary. The validity of the hypothesis was verified using 1,25-dihydroxy-vitamin D3 as a test compound. This method provides a viable approach for the characterization of A-ring hydroxylated metabolites of vitamin D as well as for related aromatic compounds.
- Young, David C.,Vouros, Paul,Holick, Michael F.,Higuchi, Tetsuo
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p. 837 - 842
(2007/10/02)
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