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13C chemical shifts and conformational analysis of S-methylthiolanium cations

✍ Scribed by G. Barbarella; P. Dembech

Publisher
John Wiley and Sons
Year
1981
Tongue
English
Weight
649 KB
Volume
15
Category
Article
ISSN
0749-1581

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✦ Synopsis

Abstract

The ^13^C NMR spectra of all cations obtained by methylation at sulphur of the mono‐and dimethylthiolanes are reported. The methyl substituent on sulphur affects the shieldings of the adjacent carbons in a manner which allows easy identification of the cis and trans isomers. For most compounds the ^13^C pattern is consistent with a half‐chair ring conformation with maximum staggering at C‐3, C‐4. Only with methyl groups at the 1,2‐or 1,2,3‐positions is the half‐chair appreciably deformed. It is suggested that in these cases the preferred conformation is a quasi‐envelope with C‐3 at the top.

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