- Synthesis and Anti-hyperglycemic Activity of New C-Glucoside SGLT2 Inhibitors
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A series of new trans-1-{4-methoxy-3-[(4-substituted cyclohexyl) methyl]phenyl}-1-deoxy-β-D-glucopyranoses (12a-12d) was synthesized. The structures of synthesized compounds were confirmed by 1H NMR and HR-MS data. The synthesis of compounds bearing large
- Wan, Xiaorong,Qin, Cheng
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p. 403 - 409
(2021/02/02)
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- Synthesis of 20-Carbaldehydes and 20-Carbonitriles of the Pregnane Series Starting with (20S)-20-Hydroxymethylpregna-1,4-dien-3-one
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An efficient six-step approach to 3-protected (20S)-3β-hydroxypregna-1,5-diene-20-carbaldehydes 8 with potential importance in the synthesis of vitamin D analogues was developed starting with (20S)-20-hydroxymethylpregna-1,4-dien-3-one (1).Oxidation of the 22-hydroxy group of 1 by means of periodinane 2 (Dess-Martin reagent) furnished the aldehyde 3 without epimerization. 3 was protected selectively at C-22 as dimethyl acetal 5.Isomerization to 6 and subsequent reduction of the 3-carbonyl group with calcium borohydride furnished the 3β-alcohol 7a with high stereoselectivity.Cleavage of the acetal to 8a occurred in a homogeneous solution of acetic acid in the presence of small amounts of water and trifluoroacetic acid.After protection of the 3-OH group 8b-d were obtained in 54percent overall yield.The in situ generated aldehyde N,N-dimethylhydrazones of 3, 8a, and 8b were converted in high yields with excellent chemoselectivity into the nitriles 12, 15a, and 15b with magnesium monoperoxyphthalate hexahydrate.The uniform (20S) stereochemistry of 3 and 8a-d was elucidated by 1H-NMR investigations. - Key Words: Pregnanes / Steroids
- Krieg, Reimar,Schoenecker, Bruno
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p. 1025 - 1032
(2007/10/02)
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- About the Influence of Geometrical Factors on Liquid Crystalline Properties-The Methylene Group as a Central Spacer Unit
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The preparation and liquid crystalline properties of four classes of substance with a central methylene spacer unit are described.As a result of our investigations, it is shown that a "one-atomic" central spacer, such as a methylene group, combined with a
- Frach, R.,Deutscher, H. -J.,Zaschke, H.,Altmann, H.
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p. 151 - 164
(2007/10/02)
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- EFFECTS OF MOLECULAR LENGTH ON NEMATIC MIXTURES - 2. ANISOTROPIC AND DYNAMIC SCATTERING PROPERTIES OF 4-ALKOXYPHENYL 4-ALKYLCYCLOHEXANECARBOXYLATE MIXTURES.
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The properties of nematic liquid-crystal mixtures of 4-alkoxyphenyl trans-4-alkylcyclohexane-carboxylates are studied as a function of temperature and their average molecular length. Mixtures are prepared with clearpoints near 72 degree C( plus or minus 3
- Margerum,Wong,Lackner,Jensen
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p. 157 - 174
(2007/10/02)
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