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Carbon‐13 NMR spectra of bromine‐containing esters
Author(s) -
Velichko F. K.,
Dostovalova V. I.,
Vinogradova L. V.,
Kh. Freidlina R.
Publication year - 1980
Publication title -
organic magnetic resonance
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.483
H-Index - 72
eISSN - 1097-458X
pISSN - 0030-4921
DOI - 10.1002/mrc.1270130610
Subject(s) - bromine , diastereomer , chemistry , chemical shift , nmr spectra database , carbon 13 nmr , spectral line , carbon fibers , stereochemistry , medicinal chemistry , organic chemistry , materials science , physics , astronomy , composite number , composite material
13 CHBrCOOR fragments of bromine‐containing mono‐ and dicarboxylates show 13 C NMR signals in the range 38–45 ppm, at 12–15 ppm to high field of their chloro analogues. The introduction of one bromine atom into the α‐CH 2 group causes a 6–13 ppm shift of the carbon signal, depending on the type of ester. The replacement of H with Br in 13 CH 2 (COOR) 2 has only a negligible influence on the 13 CH 2 signal position. The 13 CBr 2 COOR fragment signals appear in the range 50–54 ppm. 13 C NMR data, including the chemical shift values, signal multiplicities and spin‐spin couplings, make possible the identification of isomers present in isomer mixtures of bromine‐containing esters. The 13 COOR chemical shifts of diastereomers of α,β‐dibromoesters differ noticeably from each other, and the 13 C NMR spectra can thus be used to supply preliminary information about the stereochemistry of bromine addition to α,β‐unsaturated acids.