The conformational enthalpies (ΔH) of 2-methyl-(− 1.76 kcalmol− 1) and 4-methyl-1, 3- dithiane (− 1.75 kcalmol− 1) were obtained by the analysis of 13C chemical shifts as a function of temperature. These energies are in excellent agreement both with calculated values (B3LYP/6-31G (d, p)) and with literature values based on 2, 4-dialkyl-1, 3-dithiane. The results confirm the similarity between the conformational energies of the methyl group ...
[Page, Philip C. Bulman; Klair, Sukhbinder S.; Brown, Michael P.; Smith, Christopher S.; Maginn, Stephen J.; Mulley, Suzanne Tetrahedron, 1992 , vol. 48, # 28 p. 5933 - 5940]