2900-98-3Relevant academic research and scientific papers
Partial Synthesis of Cardenolides and Cardenolide Analogues. XI. Synthesis of 3-(3&β,14-Dihydroxy-5&β,14&β-androstan-17&β-yl-methyl)but-2-en-4-olide, a Homologous 5&β,14&β-Cardenolide
Lindig, Claus,Repke, Kurt R. H.
, p. 695 - 704 (2007/10/02)
Wittig reaction of 3β,14-dihydroxy-5β,14β-androstane-17β-carboxaldehyde 4 with 2-carboxy-1-ethoxycarbonyl-ethyl-triphenylphosphorane 11 followed by the reduction of the resulting half ester 5 and cyclization of the γ-hydroxy acid 6 yields the 3-alkylidenebutan-4-olide 8a which was isomerized to the 3-(steroidylmethyl)but-2-en-4-olide 9.Insertion of the methylene group between the steroidyl moiety and the but-2-en-4-olide ring strongly reduces the biological activity.
Partial Syntheses of Cardenolides and Cardenolide Analogues. X. Synthesis of 22-O-Substituted Cardenolides and Studies on the Oxidative Degradation of Cardenolides with Potassium Permanganate
Lindig, Claus
, p. 682 - 694 (2007/10/02)
The stereoisomeric 20,22-dihydroxy-cardanolides 2a and 3a as well as the oxalic acid half ester of the 3β-acetoxy-14,21-dihydroxy-5β,14β-pregnan-20-one (4a) and 3β-acetoxy-20-oxo-5β,14β-pregnane-21,14-lactone (5) were identified as intermediates of intermediates of oxidative degradation of digitoxigenin 3-acetate with potassium permanganate. 2a and 3a, after selective acylation in 22-position, were converted to the 22-acyloxy-cardenolides 7a and 7b via dehydration or acetoxyelimination after selective acetylation of the 20-hydroxy group.Saponification of both 7a and 7b yields the very stable 22-hydroxycardenolide 8a.The molecular biological activities of the 22-substituted cardenolides were investigated and discussed.
