Abstract: In the (1) H and (13) C NMR spectra of methyl 6,7-endo,sin-dibromo-7-anti-(phenylsulfonyl)bicycle-[3.1.1]heptane-6-exo-carboxylate, H(1) and H(5) protons as well as C(1) and C(5) carbon atoms show their chemical inequivalence determined by the hindered rotation of sulfonyl and ester groups about simple C-S and C-C bonds due to the existence of donor-acceptor interaction between the carbonyl C atom and the oxygen atom of the SO2Ph group. This interaction is indicated by the single crystal X-ray diffraction study detecting the shortened intramolecular contacts (2.49 with the sum of the CaEuro broken vertical bar O van der Waals radii of 3.00 ). Other features of the norpinane skeleton conformation and the spatial orientation of substituents in the single crystal are discussed. By (1) H NMR methods, the parameters of the dependence of molecular conformations on the temperature of DMSO-d (6) solution and the activation free energy a-(3)G (c) (not equal) = 80.1 kJ/mol of conformational transitions are determined. By a quantum chemical DFT calculation of the potential energy surface it is revealed that the hindered rotation of the ester group makes the main contribution to the barrier of conformational transitions.

Cite: Vasin V.A. , Petrov P.S. , Genaev A.M. , Gindin V.A. , Razin V.V.
On the spatial structure of methyl 6,7-endo, sin-dibrom-7-anti-(phenylsulfonyl) bicyclo[3.1.1]heptane-6-exo-carboxylate
Journal of Structural Chemistry. 2010. V.51. N5. P.949-955. DOI: 10.1007/s10947-010-0144-6 WOS Scopus РИНЦ

Dates:

Published print:	Oct 1, 2010
Published online:	Nov 19, 2010

Identifiers:

Web of science	WOS:000284428100021
Scopus	2-s2.0-78649509808
Elibrary	16696366
OpenAlex	W2004131935

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