336099-76-4Relevant articles and documents
Synthesis method for obeticholic acid intermediate 7-ketolithocholic acid
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Paragraph 0139; 0140, (2017/08/31)
The invention discloses a chemical synthesis method for an obeticholic acid intermediate 7-ketolithocholic acid (3alpha-hydroxy-7-keto-5beta-cholestane-24-acid), and belongs to the field of organic chemical synthesis. The method adopts cholic acid as a raw material, and through 7alpha-hydroxyl selective oxidation, side chain carboxyl esterification, 3alpha-hydroxyl etherification, 12alpha-hydroxyl methanesulfonic acid esterification, elimination, hydrogenation, hydrolysis and other reactions, the obeticholic acid intermediate 7-ketolithocholic acid is synthesized. The synthesis method for 7-ketolithocholic acid adopts cheap cholic acid as the raw material, and has the advantages of novel synthesis method, low cost, high yield, environmental friendliness and convenience in industrialized production.
First total synthesis of xestobergsterol A and active structural analogues of the xestobergsterols
Jung, Michael E,Johnson, Ted W
, p. 1449 - 1481 (2007/10/03)
The novel pentacyclic polyhydroxylated sterol, xestobergsterol A 1a, a strong inhibitor of histamine release from rat mast cells induced by anti-IgE, has been synthesized in 24 steps and good overall yield from stigmasterol 7. The Breslow remote functionalization process has been extended to several more highly functionalized steroid derivatives, especially those with oxygen functionality in the B-ring. The key steps of the synthesis of xestobergsterol A 1a and its analogues, 7-deoxyxestobergsterol A 1d and 16,23-seco-23-deoxyxestobergsterol A 73, are the Breslow remote functionalization of oxygenated steroids and for compounds 1a and 1d, a novel base-catalyzed epimerization-aldol condensation of a dione to give the desired CD-cis ring structure of the xestobergsterols. Thus the known alcohol 75, prepared from stigmasterol 7, was taken to the tetraacetate 107 which was then converted via a Breslow remote functionalization into the alkene aldehyde 114 which was transformed in 5 steps to xestobergsterol A 1a. Testing of the synthetic materials showed that the two analogues, 7-deoxyxestobergsterol A 1b and 16,23-seco-23-deoxyxestobergsterol A 73, are also potent inhibitors of histamine release with IC50 values (IC50 500 nM and 750 nM, respectively) being only 1015 times less than that of xestobergsterol A itself (50 nM).
