Cellulose 6-thio-, derivs

A number of investigations have been made on the conversion of cellulose to the 6-thio derivative, with a view to formation of disulfide cross-links. Some of the more-useful properties of wool are believed to be due to such cross-links. p-Toluenesulfonated, acetylated cellulose reacted with thiosulfate ion to give the thiosulfonate derivative (Bunte salt), which was readily oxidized to the disulfide by oxidation with iodine, according to the following equation. 

In their comparative studies, Rogovin and coworkers confirmed the sensitivity of 0-(methoxycarbonyl)celluloses toward aqueous alkali, noted earlier by Heuser and Schneider, but found an 0-[(methylthio)thiocar-bonyl] derivative to possess enhanced stability, similar to that of cellulose acetate. Thus, whereas the action of N sodium hydroxide at 25° causes almost complete de-esterification of O-(methoxycarbonyl) cellulose in 5 minutes, the methyl xanthate suffers only 20 % hydrolysis during 1 hour. No quantitative data of this nature are available for the corresponding mono-thiocarbonate. The product from its iodine oxidation was far more stable than that (see p. 147) derived from cellulose xanthate. The 0-[(methyl-thio)thiocarbonyl] derivative of methyl a-D-glucopyranoside was seemingly more alkali-sensitive than the cellulose analog described above, possibly on account of its higher solubility. 

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