Stereochemistry Determination by Powder X-Ray Diffraction Analysis and NMR Spectroscopy Residual Dipolar Couplings

Authors


  • NMR instrumentation at CMU partially supported by NSF (CHE-0130903). Use of the NSLS, BNL, was supported by DOE, Office of Basic Energy Sciences, Contract No. DE-AC02-98CH10886. S.P. thanks the College of William and Mary, Physics Dept. for funding. M.E.G. and V.E.N. thank CONICET and SeCyT-UNC for financial support. H.K. acknowledges support from ONR grants (N000140510055, N000140811235) and support for computations at the Center for Piezoelectrics by Design. A.N. thanks Centro de Supercomputación de Galicia (CESGA) for computer time, and Xunta de Galicia (PGIDIT07 PXIB 200925PR) and spanish government (CTQ2007-65310) for research grants. We thank Dr. G. E. Barboza for the collection and identification of plant material, and Prof. A. Gutierrez-Ravelo for the mass spectra. We thank Dr. N. V. Tsarevsky from ATRP Solutions for the PMMA gels.

Abstract

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Eine Frage der Technik: Dieselbe Konfiguration an C23–C26 wurde für das neue Steroidlactol Jaborosalactol 24 (1), isoliert aus Jaborosa parviflora, auf zwei unabhängigen Wegen bestimmt: NMR-spektroskopisch aus dipolaren Restkupplungen und durch Röntgenpulverbeugung. Herkömmliche NMR-spektroskopische Techniken wie die Analyse von NOEs und 3J-Kopplungskonstanten lieferten keine eindeutigen Ergebnisse.

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