The Vibrational Spectra of Tetrahydropyran and p-Dioxane

Our major purpose in the present paper will be to identify the bands which arise from the stretching vibrations of the tetrahydropyran ring. While it is not expected that these bands will occur unshifted in sugar spectra, their identification may be expected to be of assistance in the discussion of sugar spectra. In the carbohydrates the hydrogens which are attached to carbons are predominantly tertiary and bands involving them may be expected to fall at somewhat higher frequencies than C-C or C-O stretchings (e.g., see Rasmussen), but in tetrahydropyran and p-dioxane some of the hydrogen frequencies do lie in this spectral region so that we include a brief treatment of the methylene vibrations.