- Succinates and maleates of some cardenolides, and their potassium salts
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The succinates of corotoxigenin, digitoxigenin, and oleandrigenin, and the maleate of strophanthidin, and their potassium salts, have been synthesized. In contrast to the initial cardenolides (1, 4, 7, and 10), the succinates (2, 5, and 8) and the maleate (11) and their potassium salts (3, 6, 9, and 12) possess no cardiotonic activity.
- Komissarenko,Komissarenko,Derkach
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- Synthesis of 3β,14-Dihydroxy-5β,14β-pregnan-20-one C-3 Derivatives: Ozonolysis of Digitoxin and Digitoxigenin and their Derivatives followed by Zinc-Acid Reduction to the C-21 Methyl Ketone
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Ozonolysis of digitoxin, digitoxin tetraacetate, digitoxin tetrakis-(2,2,2-trichloroethyl carbonate), digitoxigenin, digitoxigenin acetate, digitoxigenin hemisuccinate and digitoxigenin 2,2,2-trichloroethyl carbonate followed by treatment with excess of zinc in acetic acid gave either the corresponding 21-hydroxy ester after 5 min or the 21-methyl ketone after 20 h.This procedure is more efficient than methods previously reported for the conversion of the α,β-unsaturated γ-lactone into an acetyl group and is applicable to the cardiac glycosides directly to give 14β-hydroxypregnan-20-one derivatives.Acidic hydrolysis of 14,21-dihydroxy- and 14-hydroxy-3β-tris(digitoxosyloxy)-5β,14β-pregnan-20-one is reported.Structures are based on 1H and 13C NMR assignments.
- Templeton, John F.,Ling, Yangzhi,Jin, Jichun,Boehmer, Mark A.,Zeglam, Talal H.,LaBella, Frank S.
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p. 823 - 829
(2007/10/02)
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- NEW METHOD OF PREPARATION OF CARDIOGLYCOSIDE HEMISUCCINATES
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An indirect method for preparation of hemisuccinates (hydrogen butanedioates) is described, consisting in reaction of hydroxy derivatives with 2-(trimethylsilyl)ethyl hemisuccinate (I), followed by removal of the 2-(trimethylsilyl)ethyl group from the mixed succinate with tetrabutylammonium fluoride.It has been applied to the synthesis of hemisuccinates derived from cholesterol (II), (20E)-21-methoxycarbonylpregna-5,20-dien-3β-ol (V), digitoxigenin (XII), digitoxin (XV) and digoxin (XVIII).The method, however, is not suitable for the preparation of estrone hemisuccinate X which is cleaved with tetrabutylammonium fluoride to give estrone (VIII).
- Pouzar, Vladimir,Cerny, Ivan,Drasar, Pavel,Havel, Miroslav
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p. 2019 - 2028
(2007/10/02)
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