127395-13-5Relevant articles and documents
Repulsive gauche conformational effect. Analysis of seven-membered rings containing endo and exo sulfur atoms
Dionne, P.,St-Jacques, M.
, p. 513 - 521 (2007/10/02)
The so-called repulsive gauche conformational effect associated with sulfur is investigated through a study of 3-methylthio-1,5-benzodioxepin (1) and 3-methylthio-1-benzoxepin (2), together with 3-fluoro- and 3-chloro-1,5-benzodithiepins (3 and 4), by 13C and 1H dynamic nuclear magnetic resonance methods.The results show that, while compounds 2, 3, and 4 exhibit a large amount of the Ce conformation, the TB form predominates for compound 1.Intramolecular stereoelectronic ?-?* orbital interactions are analyzed, together with several other factors (steric, electrostatic, and solvation), to explain the observed conformational behaviour.