P-31-NMR SPECTROSCOPY IN WOOD CHEMISTRY .2. PHOSPHITE DERIVATIVES OF CARBOHYDRATES

Selected acyclic and cyclic polyols, monosaccharides, disaccharides, higher oligosaccharides, and model compounds for lignin carbohydrate complexes were reacted with 1,3.2-dioxaphospholanyl chloride, and the P-13-n.m.r. spectra of the derivatives were obtained in order to correlate the signals with the structural details of the compounds. The derivatives of most of the carbohydrates exhibited spectra containing well resolved signals in the range 138-132 p.p.m., and the number of lines accorded with the number of hydroxyl groups in the respective compounds. The chemical shift values of the phosphorus atoms at C-1 in derivatives of monosaccharides were characteristic for the anomer involved. Since completely resolved spectra with signals characteristic for the sugars and the lignin-related parts, respectively, of relevant model compounds were obtained, the method seems very suitable for the structural elucidation of molecules derived from lignin carbohydrate complexes. The cyclodextrins (cyclomalto-hexa-, -hepta-, and -octaose) were derivatized, and on examination gave spectra dramatically differing from each other.