Conformational analysis: XXI—<sup>1</sup>H NMR study of 4,5‐dimethyl‐, 2,4,5‐trimethyl‐ and 2,2,4,5‐tetramethyl‐1,3‐dithiolanes

1-Oxo-1,3-dithiolane (4) and its cis- and trans-2-methyl (5,6), -4-methyl (7,8) and -5-methyl (9,10) derivatives were prepared by oxidizing the corresponding 1,3-dithiolanes (1-3) with NaIO(4) in water. The oxides were purified and their isomers separated using thin layer chromatography. The structural characterization was carried out with (1)H and (13)C NMR spectroscopy and molecular modelling. The sulfoxides 4-6 and 8-10 attain two S(1) type envelopes (sometimes slightly distorted) the S=O(ax) envelope greatly dominating. Cis-4-methyl-1-oxo-1,3-dithiolane is a special case exhibiting both two closely related S=O(ax) (30 and 27%) as well as S=O(eq) (21 and 22%) forms [S(1) and C(4) envelopes, respectively]. The relative energies of these conformations, the values of (1)H-(1)H coupling constants and (1)H and (13)C chemical shifts were estimated by computational methods and they support well the conclusions based on the experimental data.

show abstract

Conformational analysis: XXI—¹H NMR study of 4,5‐dimethyl‐, 2,4,5‐trimethyl‐ and 2,2,4,5‐tetramethyl‐1,3‐dithiolanes

Abstract: The 60 MHz 1H NMR spectra of seven differently substituted 4,5‐dimethyl‐1,3‐dithiolanes have been recorded and analysed. Configurational assignments are made and conformational aspects are discussed in the light of the spectral parameters.

Cited by 4 publications

References 5 publications

The conformational analysis of sulphur‐containing rings

The conformational analysis of sulphur‐containing rings

Substituent Effects on ¹³ C Chemical Shifts in Aliphatic Molecular Systems. Dependence on Constitution and Stereochemistry

1‐Oxo‐1,3‐dithiolanes—synthesis and stereochemistry

Contact Info

Product

Resources

About

Conformational analysis: XXI—1H NMR study of 4,5‐dimethyl‐, 2,4,5‐trimethyl‐ and 2,2,4,5‐tetramethyl‐1,3‐dithiolanes

Abstract: The 60 MHz 1H NMR spectra of seven differently substituted 4,5‐dimethyl‐1,3‐dithiolanes have been recorded and analysed. Configurational assignments are made and conformational aspects are discussed in the light of the spectral parameters.

Cited by 4 publications

References 5 publications

The conformational analysis of sulphur‐containing rings

The conformational analysis of sulphur‐containing rings

Substituent Effects on 13 C Chemical Shifts in Aliphatic Molecular Systems. Dependence on Constitution and Stereochemistry

1‐Oxo‐1,3‐dithiolanes—synthesis and stereochemistry

Contact Info

Product

Resources

About

Conformational analysis: XXI—¹H NMR study of 4,5‐dimethyl‐, 2,4,5‐trimethyl‐ and 2,2,4,5‐tetramethyl‐1,3‐dithiolanes

Substituent Effects on ¹³ C Chemical Shifts in Aliphatic Molecular Systems. Dependence on Constitution and Stereochemistry