Isotope shifts in 13C-n.m.r. spectra of 18O-labelled acetals; multiple labelling effects at β-carbons
Abstract
Acetals which are isotopically mono- or disubstituted with 18O show 13C-n.m.r. isotope shifts, both at directly attached carbons and at β-carbons, which are dependent on the number of labelled oxygens in an additive fashion.