ISSN:
0030-4921
Keywords:
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Carbon-13 chemical shifts of the α- and β-carbon atoms for 12 thietane 1,1-dixides, 9 thietane 1-oxides and 7 thietanes with a variety of 3-substituents [H, CH(CO2Et)2, SEt, Br, SPh, Ph, Cl, NMe2, OH, OSiMe3, OAc, OEt] are correlated according to the nature of the sulfur atom (Y=sulfone, sulfoxide, sulfide) and the nature of the 3-substituent (X) by the equations δα= aY+bX and δβ=aX+bY, where a and b are parameters characteristic of X and Y. One-bond coupling constants [J(CH)] are reported for 21 compounds. The chemical shifts for the α- and the β-carbon atoms of the sulfones show the ‘fore-membered ring sulfone effect’ (α-carbon unusually deshielded, β-carbon unusually shielded), but the α-carbon-hydrogen coupling constants are similar to those of the sulfoxides and sulfides; the β-carbon-hydrogen coupling constants are sensitive to the nature of the substituent (X) but no special β-effect is observed. Comparison of the chemical shifts of the α-methylene carbon atoms of 3-phenyl-, 3-(β-naphthyl)- and 3-(α-thienyl)-thietes with those of the coresponding sulfones also reveals the ‘four-membered ring sulfone effect’ cis- and trans-3-Substituted thietane 1-oxides may be distinguished by the greater downfield shift for the β-carbon atom in the trans-isomer.
Additional Material:
5 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/mrc.1270180207
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