THE TITLE COMPOUND [SYSTEMATIC NAME: 11-oxo-2,3-(oxy-dinitrilo)olean-12-en-29-oic acid], C(30)H(42)N(2)O(4), contains a linear array of five six-membered rings and a five-membered heterocyclic ring. The C ring, containing an α,β-unsaturated ketone, has a slightly distorted half-chair conformation, as does the A ring, with N-C-C angles 125.3 (5), 111.2 (4), 124.9 (5) and 109.2 (5)°, while the other three six-membered rings adopt chair conformations. The enanti-omer has been assigned by reference to unchanging chiral centres in the synthetic procedure. An intramolecular C-H⋯O interaction is present. In the crystal structure, inter-molecular O-H⋯O hydrogen bonds link the mol-ecules.
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http://dx.doi.org/10.1107/S1600536809020996 | DOI Listing |
Acta Crystallogr E Crystallogr Commun
October 2024
Cryssmat-Lab, Cátedra de Física, DETEMA, Facultad de Química, Universidad de la República, Av. General Flores 2124, CP 11800, Montevideo, Uruguay.
Phys Chem Chem Phys
December 2024
Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
Single-crystal structures of four alditol complexes are presented. In LuCl/galactitol and ScCl/-inositol complexes, μ-bridge-relevant deprotonations were observed. The polarization from two rare earth ions in the μ-bridge activates the chemically inert OH and promotes deprotonation.
View Article and Find Full Text PDFJ Phys Chem A
December 2024
Laboratoire de Chimie et Physique Quantiques, IRSAMC-CNRS-UMR 5626, Université Paul-Sabatier (Toulouse III), 31062 Toulouse, Cedex 4, France.
Recent work has documented conjugate polycyclic hydrocarbons presenting unusual properties: accepting full on-bond electron pairing, they could be considered as closed-shell architectures, but their ground-state wave function is actually a pure diradical singlet, free of any ionic component, in contrast to diradicaloids. These so-called molecules also differ from disjoint diradicals, which do not accept on-bond electron pairing, in that their singly occupied molecular orbitals (SOMOs) are spatially entangled rather than disjoint. The present work first extends the study to a broad series of architectures exhibiting the same properties, namely: they present two degenerate SOMOs in the topological Hückel Hamiltonian, and their pure diradical wave functions lead to symmetry-keeping geometries.
View Article and Find Full Text PDFOrg Lett
December 2024
College of Chemistry, Henan Key Laboratory of Chemical Biology and Organic Chemistry, State Key Laboratory of Coking Coal Resources Green Exploitation, Zhengzhou University, Zhengzhou 450052, P. R. China.
A visible-light-induced radical cyclization of α-brominated amides has been developed to construct benzimidazole[2,1-]isoquinolin-6(5)-ones and pyrrolidonesin in yields up to 97%. The methodology exhibits a certain functional-group compatibility with 43 examples and operational simplicity, offering a rapid and concise approach to obtain five- and six-membered rings under the irradiation of 18 W blue LED. Additionally, large-scale reaction of this method for synthesizing benzimidazo-isoquinolineones and the further transformations to useful pyrrolidones were also conducted and afforded positive results.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
December 2024
Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), 44919, Ulsan, Republic of Korea.
Entropy-driven strategy enables the systematic design of complex systems by using entropy as a quantifiable design parameter for the degree of mixing. In this study, we present mixed-linker zeolitic imidazolate frameworks (ZIFs), sod-ZIF-1 series, that features two types of six-membered rings (6MRs) with aperture sizes of 3.4 Å and 1.
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