Synthesis and carbon-13 NMR study of some methanesulfonyloxy and trifluoroacetoxy derivatives of naphthalene

Several mono- and di-methanesulfonyloxy (mesyloxy) and trifluoroacetoxy derivatives of naphthalene were prepared and their C-13 NMR recorded. The C-13 NMR spectra were analysed and the complete assignment of aromatic carbon chemical shifts reported. The substituent induced chemical shifts of naphthalene due to mesyloxy and trifluoroacetoxy groups were derived and compared with that of the hydroxy substituent. Carbon chemical shifts of disubstituted naphthalenes were calculated by simple additivity of substituent induced chemical shifts. The experimental chemical shifts were compared with the calculated shifts and deviations discussed in terms of steric and electronic effects of the substituents.