A 13C‐NMR spectral study of cellulose and glucopyranose dissolved in the NH3/NH4SCN solvent system

Abstract

AbstractThe 13C‐NMR chemical shifts of a cellulose with a DPw of 23 dissolved in the NH3/NH4SCN solvent system were found to be very similar to those of cellulose dissolved in DMSO (cellulose oligomers), in the LiCl/DMAC system and in the N‐methylmorpholine N‐oxide/DMSO system. It was concluded from this that cellulose does not react with the NH3/NH4SCN solvent. It was found, however, that glucose reacts with the solvent at C‐1 to form β‐D‐glucopyranosy‐lamine. Separation of this compound from the solvent resulted in another compound which was determined to be β,β‐di‐D‐glucopyranosylamine. The compounds β‐D‐glucopyranosylamine, N‐acetyl‐2,3,4,6‐tetra‐O‐acetyl‐β‐D‐glucopyranosylamine, β,β‐di‐D‐glucopyranosylamine, α,β‐di‐D‐glucopyranosylamine, 2,3,4,6,2′,3′,4′,6′‐octa‐O‐acetyl‐α,β‐di‐D‐glucopyranosylamine were all synthesized and the 13C‐NMR chemical shifts of these compounds are reported. It was also found that for the low‐DP cellulose sample which was used the reducing end group existed and had reacted with the solvent to form an amine at C‐1.