✍ Scribed by Atef G. Hanna; Nagwa M. M. Shalaby; Nagy A. M. Morsy; András Simon; Gábor Tóth; Shahid Malik; Helmut Duddeck
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Isolation of a new artifact (1) from Calotropis procera is reported which, apparently, is formed from the precursor calotropagenin (4) when exposed to methanol during work‐up. In addition, two more known cardenolides (2 and 3) could be identified. The structure of 1 and its full ^1^H and ^13^C signal assignment were accomplished by 1D and 2D NMR techniques. Copyright © 2002 John Wiley & Sons, Ltd.
📜 SIMILAR VOLUMES
The structure of carbon films derived from polycarbodiimide (PCDI) has been investigated in relation to carbonization temperature by using wide-and small-angle X-ray scatterings. Various parameters characterizing the microvoids in an anisotropic arrangement are deduced from the analysis of the small
At Ihe MP4/6-31 lC\*\*//6-31C\* thcoretlul level. CH:' and CH:'hsve relallvely large brrners towards proton IOU. despite the high evofhermicity of these reactions. In contrast, this activation bnrner for C#'IS very small and CH'\*only has a purely repulswe polentlal carve. CH? prefers a square plana