- Cardiotonic steroids with additional lactone rings
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Stereochemical structural transformations of cardiosteroids to create in them additional lactone rings were studied. Creation of β-lactones by reaction of a 3β-OH group and a 19-carboxylic group to give the corresponding A/B-trans cardiosteroids and creation of β-lactones by reaction of a 5β-OH group and a 19-COOH to give the corresponding A/B-cis steroids were studied. The new biologically active compounds 8(14)-dehydrobovogenin-19-carboxylic acid 3β-O-19-lactone, strophanthidine-19-carboxylic acid 5β-O- 19-lactone, cymarin-19-carboxylic acid 5β-O-19-lactone, convallatoxin-19-carboxylic acid 5β-O-19- lactone, and strophalloside-19-carboxylic acid 5β-O-19-lactone were prepared.
- Makarevich,Kovalenko,Ulesov
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experimental part
p. 742 - 745
(2011/02/25)
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- 19-NORCARDENOLIDES
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The products of the autooxidation of the cardenolides strophanthidin and erysimin in solutions have been studied.It has been established that the autooxidation of 19-oxocardenolides forms, together with 19-carboxylic acids, a complex mixture of 19-norcardenolides.The bulk of them consists of 10β-OH compounds and a smaller proportion of 10β-H compounds.Autooxidation affects both the functional group at C-10 and its transformation and also other groupings and bonds in ring A and, to some extent, in ring B, including the oxidation of the 3β-OH group, degradation of the 5β-OH group, and cleavage of the C5-C10 bond with the formation of 5,10-seco-19-norcardenolides.A possible mechanism of the formation of 19-norcardenolides is discussed.
- Makarevich, I. F.,Dikan', L. N.
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