PREPARATION AND PROPERTIES OF NEW SURFACTANTS CONTAINING D-GLUCOSAMINE AS THE BUILDING-BLOCK

Three types of new surfactants were prepared by using N-acetyl-D-glucosamine as a starting material. The first type of surfactant, sodium methyl 4,6-O-alkylidene-2-(carboxylatomethylamino)-2-deoxy-D-glucopyranoside was prepared successively by the following treatments: methyl glucosidation of N-acetyl-D-glucosamine, transacetalization with an appropriate aldehyde dimethyl acetal, deacetylation, and finally reaction of the resulting methyl-4,6-O-alkylidene-2-amino-2-deoxy-D-glucopyranoside (2-amino precursor) with bromoacetic acid. The reaction of this 2-amino precursor with methyl iodide yielded the second type of surfactant, methyl 4,6-O-alkylidene-2-deoxy-2-(trimethylammonio) iodide, in excellent yield. The last type of compound, sodium methyl 2-acetamide-4,6-O-alkylidene-3-O-[1-(carboxylato)-ethyl]-2-deoxy-D-glucopyranoside, was synthesized by the reaction of methyl 2-acetamide-4,6-O-alkylidene-2-deoxy-D-glucopyranoside with 2-chloropropionic acid. Concerning the two carboxylate types of surfactants, the compounds containing a Cg or C-11 hydrophobic chain in the alkylidene part showed higher water solubility than the corresponding compounds containing a C: hydrophobic chain. Both the micelle-forming property and the ability to lower the surface tension of these carboxylate types of compounds increased with an increase in the length of the hydrophobic chain in the alkylidene part. These compounds can be applied to new acid-decomposable types of cleavable surfactants because they contain an acetal group. The acetal bond of the ammonium type of compound was cleaved more slowly than that of the corresponding carboxylate types of surfactants in 2% aqueous HCl solution. The biodegradabilities of these compounds were also determined.