Absolute Configuration of 18-Acetoxy-Cis-Cleroda-3,13e-Dien-15-Oic Acid

Abstract

In this paper we report the absolute configuration which has been determined from the refinement of the Flack parameter, x = 0.05(5), which indicate that the correct configuration had been assigned against 1353 (99%) CuKα Bijvoet pairs. On this basis the absolute configuration was assigned as C5R, C8S, C9R and C10S. The structure of 18-acetoxy-cis-cleroda-3,13E-dien-15-oic acid consists of a clerodane skeleton and the corresponding methyl groups are α-oriented (C8, C9) while C5 is β-oriented. The acidic lateral chain is β-oriented and the double bond between C13 and C14 has E isomeric. The ciclohexene, cyclohexane rings are cis fused, and in an sofa and chair conformation respectively. In the crystal the molecules are linked by one intermolecular OH⋅⋅⋅O hydrogen bond forming 1D-dimensional chain with distance donor-acceptor of 2.060(6)Å with graph-set notation .

CRYSTAL STRUCTURE, HIRSHFELD SURFACE ANALYSIS AND ENERGY FRAMEWORK STUDY OF THE NITRONE N-BENZYLIDENE-N-BUTYLAMINO-4-Β-PYRIDYL-N-OXIDE

“…From the interest in studying the structural characterization of biologically active molecules [14][15][16][17][18][19][20][21] , we report here the single-crystal X-ray diffraction study of the nitrone derivative N-benzylidene-N-butylamino-4-β-pyridyl-N-oxide, among a series of compounds with antiparasitic properties 10 . In order to understand the nature of the described non-covalent interactions in the supramolecular network of this material, a Hirshfeld surface analysis and energy framework study was performed 22,23 .…”