Department of Chemistry, Isfahan University of Technology, Postcode 85156 Isfahan, I.R. IRAN
The 1H and natural-abundance 13C-NMR spectra of 1-thiacyclooctan-3-one (1) have been measured from 25 to -100°C. Coalescence is observed in the 1H-NMR spectra of (1) at about -80°C, and attributed to ring inversion in a boat-chair conformation, which is the predominant conformation of (1). The free energy of activation (DG¹) for this process is 9.2±0.2 kcal/mol. The 13C-NMR spectra of (1) is temperature independent.