H. Bonacorso, M. B. Costa, S. Moura
Oct 1, 2005
Citations
0
Influential Citations
14
Citations
Journal
Journal of Fluorine Chemistry
Abstract
Abstract Among the synthesis of a series of five well-known 2-trifluoroacetyl-1-methoxycycloalkenes derived from cyclopentanone and substituted cyclohexanones, this paper describes the synthesis of three new 2-trifluoroacetyl-1-methoxycycloalkenes derived from cycloheptanone, cyclooctanone and cyclododecanone in 60–68% yield. Subsequently, the 17 O NMR chemical shift analysis of the carbonyl and the methoxy groups for these cyclic molecules clearly showed the electron push–pull phenomenon and revealed large and irregular variations of 17 O NMR chemical shifts with the ring size. Finally, a more stable conformation of these trifluoroacetyl-containing cycloalkenes was determined by energy minimization calculations using Austin Model 1 (AM1) semi-empirical method and correlations between 17 O NMR data and torsion angles or oxygen net charge calculated by AM1 semi-empirical method were performed.