The present invention relates to a process to prepare sucralose. More particularly the said process relates to the production of sucralose, chemically known as, 6-Dichloro-1,6-dideoxy-β-D-fructofuranosyl-4-chloro-4-deoxy-alpha-D-galactopyranoside of formula (1)
The periodateoxidation of some derivatives of sucrose at primary positions is generally selective for the D-glucopyranoside group. A cleavage at C-2-C3 or C-3-C-4 positions was observed for the 6,1',6'-tri-O-trityl and 6,1',6'-tri-O-(tert-butyldemethylsilyl) derivatives, respectively. The periodateoxidation was more complete for all other derivatives with a cleavage at C-2-C-3 and C-3-C-4.
The self-assembling properties of the 6-O- and 6-O-alkylsucrose mixtures with different chain lengths including octyl, decyl, dodecyl, and tetradecyl under aqueous conditions were studied and compared with those of the 6-O- and 6-O-hexadecylsucrose mixture previously reported. The title compounds were synthesized from sucrose in five steps. The results of scanning and transmission electron microscopes, powder X-ray diffraction, and dynamic light scattering measurements indicated that the self-assembling properties of octyl, decyl, and dodecyl derivatives were completely different from those of the 6-O- and 6-O-hexadecylsucrose mixture. The three derivatives reported here primarily formed lamellar planes, which further induced the formation of vesicle-type particles under aqueous conditions, whereas the previous derivatives primarily formed spherical micelles in water, which further assembled according to face-centered cubic organization by a drying process from the aqueous dispersion. It was also found that the 6-O- and 6-O-tetradecylsucrose mixture showed concentration-induced micelle-lamellar transition behavior in an aqueous dispersion. Furthermore, the mixing of a regioisomer, 6-O-hexadecylsucrose, with 6-O-hexadecylsucrose induced different self-assembling properties from that of 6-O-hexadecylsucrose alone, but this effect did not appear in the self-assembling of the 6-O- and 6-O-octylsucrose mixture.
Self-assembly of 6-O- and 6′-O-hexadecylsucroses mixture under aqueous conditions
In this paper we report the self-assembly of 6-O- and 6'-O-hexadecylsucroses mixture under aqueous conditions The mixture was synthesized by a five-step sequence from sucrose The SEM image of a sample prepared by drying a dispersion of the mixture in water showed nanoparticles with the diameter of similar to 50 nm and aggregates that were formed by further assembly of them The XRD measurement of the sample exhibited the diffraction pattern assignable to face-centered cubic (FCC) structure and the diameter of a sphere which took part in the FCC structure was calculated to be 5 1 nm This value was relatively close to that observed in the DLS measurement of a dispersion of the mixture in water and estimated for a spherical micelle based on the molecular sizes of the two sucrose ethers On the basis of the above findings the following self-assembly process of the mixture under aqueous conditions was proposed The mixture formed the spherical micelles with the diameter of similar to 5-7 nm in water The micelles regularly organized according to the FCC structure during the drying process from the aqueous dispersion to construct the nanoparticles with the diameter of similar to 50 nm Several numbers of the nanoparticles further assembled to form the aggregates (C) 2010 Elsevier Ltd All rights reserved