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Homodecoupled 1,1- and 1,n-ADEQUATE: Pivotal NMR Experiments for the Structure Revision of Cryptospirolepine
Josep Saurí1, Wolfgang Bermel2, Alexei V Buevich1
1Process & Analytical Chemistry, Merck Research Laboratories, Mailstop: 800-D133, 126 E. Scott Ave, Rahway, NJ 07065 (USA).
Abstract:
Cryptospirolepine is the most structurally complex alkaloid discovered and characterized thus far from any Cryptolepis specie. Characterization of several degradants of the original, sealed NMR sample a decade after the initial report called the validity of the originally proposed structure in question. We now report the development of improved, homodecoupled variants of the 1,1- and 1,n-ADEQUATE (HD-ADEQUATE) NMR experiments; utilization of these techniques was critical to successfully resolving long-standing structural questions associated with crytospirolepine.
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