Efficient Syntheses of Pyrofolic Acid and Pteroyl Azide, Reagents for the Production of Carboxyl-Differentiated Derivatives of Folic Acid
摘要:
Reaction of folic acid (1) with excess trifluoroacetic anhydride provides access to both the previously unknown N-10-(trifluoroacetyl)pyrofolic acid (8) and pyrofolic acid (9). Reaction of either of these materials with hydrazine selectively affords pteroyl hydrazide (13), which may be oxidized to pteroyl azide (27) on a large scale (62% overall from 1 without the need for chromatography). Treatment of 27 with differentially protected glutamates provides a convenient and high-yielding synthesis of differentially protected, optically pure folates.
C−H Bond Activation for the Synthesis of Heterocyclic Atropisomers Yields Hedgehog Pathway Inhibitors
作者:Gang Shan、Jana Flegel、Houhua Li、Christian Merten、Slava Ziegler、Andrey P. Antonchick、Herbert Waldmann
DOI:10.1002/anie.201809680
日期:2018.10.22
pronounced bioactivity, and methods for their efficient synthesis have gained widespread attention. However, enantioselective synthesis of axially chiral 4‐arylisoquinolones by means of C−Hactivation has not been reported to date. Described here is a rhodium (III)‐catalyzed C−Hbondactivation and annulation for the atroposelective synthesis of axially chiral 4‐arylisoquinolones. The method employs
An endothelin antagonist comprising as the active ingredient a prostanoic acid derivative wherein the &agr;-chain has eight or more skeletal carbon atoms.
Erikson, Torsten K. G.; Bryan, Jeffrey C.; Mayer, James M., Organometallics, 1988, vol. 7, # 9, p. 1930 - 1938
作者:Erikson, Torsten K. G.、Bryan, Jeffrey C.、Mayer, James M.
DOI:——
日期:——
Lamy, A., Comptes Rendus Hebdomadaires des Seances de l'Academie des Sciences, 1864, vol. 59, p. 781 - 781
作者:Lamy, A.
DOI:——
日期:——
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