Researches on Cellulose, 1895-1900Cross, C. F. (Charles Frederick)
Science
Researches on Cellulose, 1895-1900
Cross, C. F. (Charles Frederick)
Cellulose
The latter has been specially examined with regard to its proportion of
OH groups, as a necessary preliminary to the investigation of esters, in
producing which the entire complex is employed. It will be shown that
the ester groups can be actually localised in various ways, as in the
main entering the cellulose residues alpha and beta. But that the
lignone group takes little part in the reactions may be generally
concluded on the evidence of its non-reactivity as an isolated
derivative, (1) By chlorination, &c. it is isolated in the form of an
amorphous body, but of constant composition, represented by the formula
C_{19}H_{18}Cl_{4}O_{9}. This compound, soluble in acetic anhydride, was
boiled with it for six hours after adding fused sodium acetate, and the
product separated by pouring into water. The dilute acid filtered from
the product contained no hydrochloric acid nor by-products of action.
The product showed an increase of weight of 7.5 p.ct. For one acetyl per
1 mol. C_{19}H_{18}Cl_{4}O the calculated increase is 8.0 p.ct. It is
evident from the nature of the derivative that this result cannot be
further verified by the usual analytical methods. (2) The chlorinated
derivative is entirely soluble in sodium sulphite solution. This
solution, shaken with benzoyl chloride, with addition of sodium hydrate
in successive portions, shows only a small formation of insoluble
benzoate, which separates as a tarry precipitate. (3) The empirical
formula of the lignone complex in its isolated forms indicates that very
little hydrolysis occurs in the processes of isolation. Thus the
chlorinated product we may assume to be derived from the complex
C_{19}H_{22}O_{9}. In the soluble by-products from the bisulphite
processes of pulping wood the lignone exists as a sulphonated
derivative, C_{24}H_{23}(OCH_{3})_{2}.(SO_{3}H).O_{7}. The original
lignone may be regarded as passing into solution as a still condensed
complex derived from C_{24}H_{26}O_{12} (Tollens). There is evidently
little attendant hydroxylation, and another essential feature is the
small molecular proportion of groups showing the typical sulphonation.
It appears that in the lignone the elements are approximately in the
relation C_{6} : H_{6} : O_{3}, and it may assist this discussion to
formulate the main constitutional types consistent with this ratio,
viz.:
(1) The trihydroxybenzenes C_{6}H_{3}(OH)_{3}.
(2) Methylhydroxyfurfural C_{5}H_{2}O.(OH)(CH_{3}).
(CH_{3})
/ \
(3) Methylhydroxypyrone CO<C_{4}H_{2} O
\ /
(OH)
__________________
| |
(4) Trioxycyclohexane CH--CH--CH--CH--CH--CH
\ / \ / \ /
O O O
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