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;i 4-O-metl1ylgl~1curo11oxy1a11 has been isolated in almost quantitative yielcl from the 117ood of trembling aspen ( P O~I C~Z L S tretnz~loides Michx.). The hernicellulose was electrophoretically hoinogeneo~is and had a number-average degree of polyrnerizatio~~ of 212. Partial hydrolysis gave D -~Y~o s~, galacturonic acid, 4-0-~nethylglucuronic acid, and 2-0-(4-0-methyl-a-Dglr~copyranosyluronic acid)-D-xylopyranose. Methanolysis and hydrolysis of the fully methylated polysaccharide, which contained 108 xylose residues per average molecule, gave 2-0-lnethylxylose, 2,3-di-0-methyl-D-xylose, 2,3,4-tri-0-methyl-~-xylose, and methyl 2-0-(2,3,4-tri-0-methyl-a-D-glucopyranosyluronic acid)-3-0-methyl-D-xylopyranoside in a inole ratio of 0.2:95:1:11. I t is concl~lded that the hemicellulose contained a linear frarneworl; of approximately 200 (1 --, 4)-linked P-D-xylopyranose residues and that, on the average, every ninth xylose unit carried a (1 -, 2)-linked 4-0-methyl-a-D-glucuronic acid residue directly attached to the xylan backbone. The polysaccharide is evidently similar to the 4-0-methylgl~~curon-oxylalis occurring in the \\rood of all arborescent angiosperms so far investigated.The xylan present in trembling aspen was the first wootl hernicell~~lose to bc subjectetl to detailed structural investigations. Jones and Wise (1) on hydrolysis of aspen wootl obtained several nlonosaccharides, xylobiose, xylotriose, D-galacturonic acid, 4-0-methyl-D-glucuronic acid, and ~-0-(4-0-methyl-a-~-g~ucopyranosyluro1lic acid)-u-sylop~~ranose! a11 of which were uneq~~ivocally identified. Millis and PUI-ves (2) isolated froin the saine wood four iractio~ls containing vario~is amounts of hesuronic, 4-0-i11etl1ylgluc~1roili~ and (1 -+ 4)-1inl;ed xylose residues. Partial hydrolysis yielded a crystalline alc1otriu1-onic acicl containing oue 4-0-metllylgl~~curonic acid and two xylose residues. The polysaccl~aricle appeared to be extensively branched and was considered to possess non-reduciilg entl groups of hexuroizic acid rather than xylopyranose residues.Jones, Merler, and Wise (3), on direct extraction of aspen wood with alkali, obtainetl a hemicellulose fraction in a yield of 19%. This material had a specific rotation of -75" and contained 1.7y0 ~nlethoxyl and 9.2y0 uronic anhydride groups. I-Iydrolysis yielded nlostly xylose in addition to minol-ainounts of hexoses, arabinose, and rhamnose. On electrophoresis, the material was resolvable into two components, while on enzymic hydrolysis, 2@y0 was enzymc-resistailt. On the basis of results obtained by the methylation technique, the authors co~lcluded that the xylose-containing hemicelluloses coilsisted of (1 -) 4)-linlied xylose residues to which were attached, through positions 2 and 3, end groups of L-arabinofuranose and side chains terminated by uronic acid residues. I t was pointed out that the acid side chains might contain both glucose and xylose I-csidues, since 2,3,6-tri-0-methyl-D-glucose and 3,4-di-O-rnethyl-~-xylose were obtainecl 011 hydrolysis of the methylated polysacch...

Can. J. Chem. Downloaded from www.nrcresearchpress.com by 34.213.178.48 on 05/10/18For personal use only. SEG.4LL diYD PPORI E S : .ICTIO.V OF HE'DRO.YYL.I.\IISEStil and perhaps even in a selective u~a )~, but technical difficulties preventetl a iLlll investigation of this possibility.When 1 gnl. of cellulose trinitrate \\:as dissol~~ecl in 25 cc. of pure dry pyi-idine a t room temperature, the viscosity of the solution, originally high, dinlinishetl to that of the solvent within two days; the solution became deep yellow or orange, and the addition of nlucl~ water precipitated a 40% yield of cellulose with a nitrogen content of 12.0% (substitution 2.2). The yield was only 15% when fixre days elapsed before the acldition of the water. When, however, the original pyridine solution contained a large excess, 5 gni., of pure hydroxylamine, practically no color developed, the viscosity decreased much more slowly although the reaction was still exothermic, and large volunles of a colorless gas were vigorousl~-evolved. This gas was shown by analysis in an Orsat apparatus and by its density to be nitrogen of 99y0 purity, and in one experiment the moles collected per glucose residue in the trinitrate were 0.94 and 1.05 after 4.5 and 11 hr., respectively. A second experiment yielded 1.00 moles in 13 hr., and thereafter the gas evolution was exceeclingly slow. These values were correct, in spite of the fact that the formation of gas in similar experiinents with many technical nitrates was much greater (16). Precipitation of the solution after 11 hr. gave a nearl~r quantitative yield of strong white fibers whose total nitrogen content of 10.670 (:orresponded to a substitution of 1.9. A lower nitrate nitrogen content of 10.Oyc, however, suggested a substitution of 1.70 nitrate and 0.08 oxime groups. These substitutions remained practically unchanged a t 1.68 and 0.08, respective1~-, when the reaction was allowed to proceed for 76 hr., although in this case the viscosity of the original solution was considerably lower. In agreement with this observation, the nitrogen content of the fibers was not changed by re-solution for three days in pyridine-hydroxylan~ine, and decreased by only 0.4% after solution for 18 hr. in pure pyridine.Several attempts to detect the carbonyl groups expected in the fibers by condensation with o-methylhydroxylanline, CH30NH2, introduced only 1% or less oi methoxyl groups (substitution 0.08 or less) and the reaction was presunlabl!-restricted to the replacement of the oxime already present by o-niethyloxime units. Attempts to remove the supposed oxi~ne group by hydrolysis with 0.5% sulphuric or 1.5yo hydrochloric acid in various solvent mixtures a t room temperature for several days gave negative results, but methylation with diazomethane introduced 0.5yo of methoxy groups (substitution 0.04). These groups probab1~-corresponded to the o-methyloxi~ne because diazomethane, when anhydrous, \\.as known not t o methylate aliphatic alcohols of an ordinary type. Although free carbonyl groups could not be dete...

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Cyclohexerie-3-01 acetate was readily made fro111 cyclohesene and when oxidized, preferably with performic acid, gave 20 to 25y0 yields of partly acylatecl cis-cis-trans-cyclol~exane-1,2,3-triol, but only 1 to 27, oT the cis-trans-cis isomer. The striictures of the three cyclohexa~~e-1,2,3-triols were deduced froin the theory of the Walclen Inversion.

Fritsch's cyclization of N-(a-veratrylveratry1idene)-an~inoacetal in sulphuric acid was shown to give 1.1% of papaverine and 23% of an isomer, n1.p. lG4.5-165.5"C.; hydrochloride, m.p. 212°C. decomp., which was supposed to be 4,5-bis(3,4-dirnethoxypheny1)-2fI-pyrrolenine, produced by an internal condensation of the acetal or the corresponding aldehyde with the reactive methylene group. A similar structure was proposed for another unidentified isomer prepared by Schlittler and Miiller. Ilydrogenation of Fritsch's acetal gave N-(a-veratrylveratry1)-aminoacetal, m.p. 69.5-7O0C., which was cyclized to a base, m.p. 155.5-156°C.; N-aceiyl derivative, m.p. 203.5-204"C., formulated as 2,3-bis(3,4-dimethoxypheny1)-3-pyrroline. Substances pres~imed t o be the intermediate aldehyde and aldol were isolated as colorless oils. Condensation of the dil-&one veratril with aminoacetal, followed by cyclization of the crude product, constituted a new two-step synthesis of papaveraldine in 8y0 yield, and the reduction of the latter to papaverine was known.Other crystalline compounds prepared incidentally and thought to be new were veratril monoanil, m.p. 172-173°C.; a,al-biveratrylidenean~ii~oacetal, m.p. 101-102°C. ; a compound formulated as 2,3-bis(3,4-dimethoxyphenyl)-4-ethylmercaptopyrrolidine hydrochloride, m.p. 184-185°C.; from this a n unidentified mercury complex, n1.p. 109°C. decornp.; 4,4'dibe11zylosy-3,3'-dimethoxydesoxybenzoin, n1.p. 141-142°C.; and its osime, m.p. 137.5"C.

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