mm., wjJ 1-4334, hydrolysed to methyl alcohol, tri

methylene glycol, and acraldehyde under conditions which do not effect the hydrolysis of trimethylene glycol mononiethyl ether, b. p. 153°/768 mm., nft 1-4126.

2-p-Hydroxyethyl-l : 3-dioxan is prepared synthetic­

ally, by the action of sodium hydroxide on 2-fi-chloro- ethyl-1 : 3-dioxan, b. p. 74—75°/9 mm., nf, 1-4542, obtained by the action of hydrogen chloride on acraldehyde and trimethylene glycol.

AcetylcycZoaldol (loc. cit.) is converted similarly by hydrogen into 4:-methyl-2-$-acetoxy-Ti-propyl-\ : 3-di­

oxan, OAc;CH]Me-CH2-C H < Q > C3H5Me, b. p. 114—

116°/15 mm., n~,f 1-4347, dimeric as vapour, also obtained when the monomeric acetylq/cfoaldol is passed with hydrogen a t 200°/22 mm. over palladised asbestos. I t is hydrolysed lay alkali hydroxide to i-m ethyl-2-$-liydroxypropyl-l : 3-dioxan, b. p. 100°/

15 mm., and by acids to crotonaldehyde and butanc- ay-diol, b. p. 108— 109°/12 mm., »iff* 1-4418.

H . Wr e n. S te r e o iso m e r ism of o x im e s. T. P. Ra ik o w a

(Ber., 1929, 62, [2?], 1626— 1637).— The observation that those unsymmetrical oximes which form an

exception to the Hantzsch-W emer theory are capable of adding hydrogen cyanide directly, whereas those which harmonise with the theory do not possess this ability, shows that addition does not occur, as pre­

viously assumed, at the double linking between the 0 and N atoms, but at some other portion of the oxime molecule. A second double linking can be produced in suitable cases by desmotropic change;

R-CiCHgjrN-OH — >- R-C(:CH2)-NH-OH, thus yield­

ing ^-oximes which may be produced directly by the oximation of the enolic forms of aldehydes and ketones. The essential condition for the formation of a 0-oximc is the presence in one at least of the hydro­

carbon residues of a mobile hydrogen atom which can wander to the nitrogen atom. This condition is fulfilled by all the oximes of aldehydes and ketones in which one valency of the oximino-group is attached directly to a methyl or methylene residue; a methene group appears incapable of allowing desmotropic change. The transformation of the oximino- to the hydroxylamino-group causes free movement in the nitrogen atom, and the oxime consequently loses its ability to exist in stereoisomeric modifications accord­

ing to Hantzsch and Werner.

The ^-oximes, ~C(!C!)-NH-OH, are closely related to the hydroxamic acids ~C(;CK)-NH-OH, with which they share the ability to give intense red colorations with ferric chloride. Examination of a large series of oximes shows that only those members which are constitutionally capable of desmotropic change give a colour with the reagent, whereas those in winch such change is impossible do not react. The behaviour of an oxime towards ferric chloride is therefore a ready criterion of its behaviour towards hydrogen cyanide and the Hantzsch-Werner theory. The oximes are tested in alcoholic solution or, if not preformed, it is usually sufficient to boil the carbonyl compound in alcoholic solution with hydroxylamine hydrochloride and to test the cold solution. q/cZoPentanone, cyclo- hexanone, menthone, carvone, pulegone, and camphor in which the methylene group is present in the ring pass into desmotropic ^-oximes like the purely ali­

phatic compounds. Caution is required in applying the test to certain aldoximes on account of their ready oxidisability to hydroximic or hydroxamic acids.

The group -C(-NH-);N-OH does not appear capable of desmotropic change to •C(:N>)-NH*OH, whereas the transition R-C(NH2):N-OH =^= R-C(:NH)-]SrH-OH is

possible. H . Wr e n.

D io x im e s . LII. G. B. Se m e r ia and B. So m ig-

l ia n o (Gazzetta, 1929, 5 9 , 258—265).—The rate of formation of methylglyoxime from oximinoacetone and hydroxylamine at different acidities has been studied (cf. Olander, A., 1927,1036). Hydroxylamine is determined by adding iodine and determining the excess, making a correction for the reaction between iodine and oximinoacetone, and the results are plotted in the form of curves for 13 different p K values, from 1-2 to 12. The velocity of reaction increases rapidly as the p R increases. E. W . Wig n a l l.

H y d r o ly sis of a cety la ted s u g a r s and s im ila r su b sta n ce s. G. ZEMPLtiN and E. Pa c s u (Ber.

1929, 6 2 , [J3], 1613— 1614).—A c e t y l compounds of sugars which do not possess reducing groups after

912 BRITISH CHEMICAL ABSTRACTS.----A.

hydrolysis can be hydrolysed in methyl-alcoholic solution on the water-bath with minimal amounts of sodium methoxide. The instances described include raannitol from the hexa-acetate, p-glucosan from the triacetate, sucrose from the octa-acetate, thioiso- trehalose from the octa-acetate, salicin from its penta-acetate, and a-methylmannoside from the tetra-acetate. The acetates of reducing sugars are similarly hydrolysed, but the solutions become yellowish-brown, so that it is preferable to use the cold

chloroform process. H. Wr e n.

U ltr a -v io le t lig h t, in su lin , and a m in o -a cid c a ta ly sis [in th e oxid a tio n of su g a rs]. J. M. Or t.

—See this vol., 889.

D e co m p o sitio n of su g a r s and g lu c o sa m in e s in a d ilu te a lk a li solu tio n . R. Masui (Osaka J. Med., 1928, 27, 1437— 1446).—The quantity of methyl- glucose produced by distillation of a slightly alkaline solution decreases in the order : lævulose, dextrose, glucosamine, the residue being lactic acid. A phos­

phate buffer retards the decomposition of dextrose.

Ch e m ic a l Ab s t r a c t s. B eh aviou r of d ex tr o se w h en h eated in alk alin e solu tio n . F. Fi s c h l e r, K. Tâ u f e l, and S. W.

S ouci (Biochem. Z., 1929, 208, 191—211).—The effect of temperature, time of heating, and concentra­

tion on the acids produced by the action of alkali hydroxide on dextrose was studied. Rise of temper­

ature up to 140— 150° increases the amount of acid formed ; above this the amount decreases. Using dilute alkali (0-7N) the yield of acid increases with time of reaction at 98-5° and at 140° ; in the latter case it reaches a constant value after 4 hrs. W ith 102V- potassium hydroxide the constant value is reached in

| hr. With increase in the amount of alkali there is a rapid increase in the amount of acid, followed by a slow decrease. In very concentrated solution there is no caramélisation. The lowest sugar concentrations give the highest percentage of acid.

The acids formed were qualitatively investigated ; indications of carbon dioxide, acetic, lactic, and glycollic acids were obtained using both 1-2A7- and lOJV-alkali, and at the lower concentrations formic and oxalic acids in addition. Using l-2i\r-alkali, distill­

ation of the acidified product yielded 7-2%, steam distillation 10-1%, ether extraction 49-7% of the total acid and 29-5%, 35-1%, and 8-9%, respectively, with lOjV-alkali. J. H. Bi r k i n s h a w.

M e ch a n ism of ta u to m e ric in terch a n g e and th e effect of stru ctu re on m o b ility and eq u ilib riu m . IV. M e ch a n ism of acid ca ta ly sis in th e m u ta r o t­

ation of n itr o g e n d eriv a tiv es of tetra -a cety l- g lu co se. J. W. Ba k e r.—See this vol., 889.

y -A cetyl-ap -isop rop ylid en eglu cose and it s r e ­ a rran g em en t in to Ç-acetyl-a(5-tsopropylidene- glu cose. K. Jo s e f h s o n (Svensk Kem. Tidskr., 1929, 41, 99— 106).—Prolonged treatment of y-acetyl- dnsopropylideneglucose (I) with slightly diluted acetic acid and subsequent removal of volatile products at 30—35°/vac. affords y-a-cetyl-a.$-isopropyUdeiieglucose (II), m. p. 125— 126° (corr.), [a]^gvcIl0W—20-1° in water. Treatment of II with acetone and anhydrous copper sulphate at the ordinary temperature regener­

ates I. The rotation of an aqueous solution of II

shows no change after 16 hrs., but wrhen a drop of dilute ammonia is added, isomérisation into Ç-acetyl- ap-isopropylideneglucose, m. p. 144— 146° (cf.

Fischer and Noth, A., 1918, i, 225), is complete after 5 min. Whilst II is stable in acetic acid solution rearrangement does take place in a slightly acid medium, and the velocity of the change has been measured polarimetififcally at p n 5-81, 6-75, and 7-1.

The velocity is approximately proportional to the concentration of hydroxyl ions, and is of the same order as that of mutarotation of a reducing sugar.

Rapid isomérisation occurs at about p a 9. The conversion of Robison’s hexosemonophosphate into zymophospkate is considered to involve a similar

rearrangement. H . Bu r t o n.

C rystallin e te tra -a c ety l-a -g lu co se. H. H.

Sc h l u b a c h and I. Wo l f [with P. St a d l e r] (Ber., 1929, 62, [23], 1507— 1509).—The action of silver carbonate on §'-acetochloroglucose in moist ether proceeds so slowly that isomérisation of the product to the equilibrium mixture of tetra-acetyl-a- and -p-gluc- ose occurs. Reaction occurs much more rapidly in highly purified acetone to which water has been added in definite amount and leads to the isolation of 2 : 3 : 4 : Q-tetm-acetyl-a-glucose, m. p. 107— 108°, [a]“

-f-138-9° in chloroform, [a]?? +139-4° to +83-1° in alcohol within 14 days or immediately on addition of

ammonia. H. Wr e n.

D isp la c em e n t of th e eq u ilib riu m between n o rm a l and y -g a la c to se in solu tio n . H. H.

Sc h l u b a c h and V. Pr o c h o w n ic k (Ber., 1929, 62, [5 ], 1502— 1507).—The observation of Riiber and Minsaas (A., 1926, 1228) that y-galactose is formed from the two normal forms of galactose with absorp­

tion of heat indicates the probable displacement of the equilibrium in favour of the y-form as the tem­

perature is raised. This is indicated by observation of the variation of the specific rotation of the equili­

brium mixture in pyridine with varying temperature and confirmed by treatment of such mixtures with acetic anhydride and preparation of the [3 -variety of penta-acetyl-y-galactose. In boiling pyridine the (3-form of y-galactose appears to be present in 23-4%

proportion. H . Wr e n.

T rip h en y lm eth y l eth er of m a n n ose. N ew tetra -a cety lm a n n o se. B. H e l f e r i c h and J . F.

L e e t e (Ber.,. 1929, 62, [5 ], 1549— 1554).—¿-Mannose is converted by triphenylmethyl chloride at the atmospheric temperature into f>-d-ma?mose 6-tri- phenylmethyl ether, m. p. 160— 170° after softening at 140°, .[«]g - 2 - 0 ° in chloroform, [a]1,? - 3 - 7 ° to 20-4°

in pyridine. Treatment of the crude product with acetic anhydride affords fi-tetra-acetyl-d-mannose 6-tri- phenylmethyl ether, m. p. 204—206° (corr.), [a]“ —2-6° in chloroform, and a-tetra-acetyl-d-mannose Q-triphenyl- methyl ether, m. p. 130-5— 131-5° (corr.), [a]“ —73-4°

in chloroform (possibly accompanied by a second, isomorphous form , m. p. 123—124°), separated from one another by crystallisation from alcohol. Either form is hydrolysed to fZ-mannose 6-triphenylmethyl ether described above. Hydrogen bromide in glacial acetic acid transforms the (3-tetra-acetate into 1 : 2 : 3 : 4:-tetra-aeetyl-$-d-mannose> m. p. 135-5—

136-5° (corr.), [a]“ - 2 2 - 5 ° in chloroform ; in aqueous

ORGANIC CHEMISTRY. 913 solution in ordinary glass tubes mutarotation is

observed, ascribed, at least in part, to migration of acyl groups catalysed by alkali. Further acétylation gives p-penta-acetyl-iZ-mannose, m. p. 116°, [V|57

—24-1° in chloroform. The assignation of the tri- phenylmethyl group to the position 6 is based 011 the conversion of the tetra-acetylmannose by phosphoryl chloride in pyridine into tetra-acetyl-fi-d-mannose-ti- chlorohydrin, m. p. 142— 143°, [a]1,; —7-6° in chloro­

form, the chlorine atom of which reacts very sluggishly, whereas in Freudenberg’s ditsopropylidenemannose-l- chlorohydrin it is highly reactive. Similarly, with thionyl chloride ditetra-acelyl-$-d-mannose 6-sulphite, m. p. 173— 175° (corr.), [ajg —33-1° in chloroform, is

obtained. H. Wr e n.

M od el e x p e r im e n ts b a sed on th e th eory of alcoh olic ferm en tation . I. D e grad ation of di- /sop rop ylid en efru ctose su lp h ate. H. Oh l e and J. Ne u s c h e l l e r (Ber., 1929, 6 2 , [B], 1651— 1658).—

It is assumed that in the initial stage of alcoholic fermentation the sugar or its phosphate must undergo dehydrogenation to yield reactive compounds which suffer fission between the y- and 8-carbon atoms and that therefore oxidation products of dextrose or lævulose must exist which, under very mild conditions, decompose into three-carbon or simpler products.

With diisopropylideneglucose or a-difsopropylidene- fructose it does not appear possible to limit the action to the oxidation of the sec.-carbinol group 3 to the keto- group, whereas p-di/sopropylidenefructose gives 2-ketoditsopropylidenegluconic acid. Potassium fi-di- isopropylidenefructose sulphate, hemiliydrate, incipient decomp, about 210°, [a]$ —21-91° (also anhydrous-, corresponding sodium salt, incipient decomp, about 200°, [ a ] —22-53°), is oxidised by potassium per­

manganate at 100° without marked production of sulphate ions if the oxygen used does not exceed 2 atoms, but much material remains unchanged. With increasing amounts of oxygen reaction occurs with formation of a dextrorotatory intermediate, the production of which is at a maximum with 6 atoms of oxygen. Under these conditions about 15% of the material is oxidised to carbon dioxide and sulphuric acid, 15% remains unchanged, about one third is converted into 4 mois, of carbon dioxide and 1 mol. of the compound, C 02K-CH2-0-S 03K, which darkens at 250° but does not melt below 300° (prepared also from glycollic and chlorosulphonic acids in pyridine), whereas the remainder affords the dextrorotatory tri-potassium salt CMe2<^ q _ ^ CH (CO K ) ^ 3^' ^j'dro-lysis of the last-named salt with iV-hydrochloric acid at 100° yields acetonc, sulphuric acid, methylglyoxal, glycollic acid, and carbon dioxide, the yield of mcthyl- glyoxal, isolated as the disemicarbazone, being 75—

80%. If hydrolysis is effected at about 35° and inter­

rupted as soon as the solution is optically inactive, the yield is only about 30%. I t appears therefore that the salt first loses the wopropylidene group and yields the sulphuric ester of dihydroxyaeetone, which sub­

sequently gives methylglyoxal and sulphuric acid.

H . We e n. T h io -su g a rs an d th eir d erivatives. XIV.

a-G lucothiose [a-th ioglu cose]. W . Sc h n e i d e r

and H. Le o n h a r d t (Ber., 1929, 6 2 , [B], 1384— 1389;

cf. A., 1928, 872).—The sodium compound of p-thio- glucose is preserved in aqueous acidic solution until mutarotation is complete and the dried product of the reaction is treated with acetic anhydride and pyridine at 0°, thus yielding a mixture of a- and (3-t-hioglucose penta-acetates, separated into its components by fractional crystallisation from alcohol. a.-Thioglucose penta-acetate has m. p. 128— 129°, [a];’; -)-132-6° in s-tetrachloroethane. I t is hydrolysed by sodium methoxide to the sodmm compound

CGH1105SNa,2H20 , m. p. 129— 130° (dccomp.) after softening at 100° when rapidly heated, [a]g +142-93°

in water [also anhydrous, m. p. 155° (decomp.) after becoming yellow at 130°]. Free a-thioglucose is strongly dextrorotatory in aqueous solution, but the specific rotation slowly diminishes and attains an equilibrium value about 15—20° higher than that observed with the equilibrium mixture from the corresponding p-compound. aa-Diglucosyl disulphide, from the sodium compound and iodine, has [a]1,?

+535-5°, whereas the value [<x]$ -1 4 9 -3 ° is now recorded for the (3-derivative. H. Wr e n.

S y n th e sis of su cro se. A. Pic t e t and H. Vo g e l

(Ber., 1929, 6 2 , [5 ], 1418— 1422; cf. A., 1928, 510, 741; Zemplen, this vol., 683).—Full details are given of the preparation of tetra-aeetyl-y-fructose, the con­

densation of the tetra-acetates of glucose and y-fructose, and the isolation and hydrolysis of sucrose

octa-acetate. H. Wr e n.

U n u su a l co u rse of th e so lu b ility of c a lc iu m h y d ro x id e in d ilu te so lu tio n s of su cro se . P.

Fu c h s (Ber., 1929, 6 2 , [£], 1535— 1538).— The solu­

bility at 17— 17-5° is determined by successive addition to the sugar solution of known concentration of iY-sodium hydroxide and a slight excess of about 2iV-calcium chloride solution. After 5 min. the mixture is filtered and the filtrate is titrated with A-hydrochloric acid in presence of methyl-orange.

The solubility of calcium hydroxide at first increases uniformly with increasing concentration of sucrose, passes through a maximum and minimum, and then again increases uniformly. The curve closely resembles the pressure-volume graph of a non-ideal gas somewhat below its critical temperature.

H. Wr e n. O ptical ro ta tio n and a to m ic d im en sio n s.

VIII. H a lo gen o h ep ta -a cetyl d eriv a tiv es of m e li- b io se and m a lto se . S tru ctu r es of b io s e s and of cellu lose. D. H. Br a u n s (J. Amer. Chem. Soc., 1929, 5 1 , 1S20— 1831).—The isolation in a pure state of fluoromelibiose hepta-acetate, m. p. 135°, [a|j?

+ 149-7° (all rotations measured in chloroform);

chloromelibiose hepta-acetate, m. p. 127°, [ajjj +192-5°;

bromomelibiose hepta-acetate, m. p. 116°, [a]™ +209-9°;

fluormnaltose hepta-acetate, m. p. 174— 175°, [a]“

+ 1 1 1-1°; chloromaltose hepta-acetate, m. p. 125°, [ajg +159-5° (cf. Foerg, A., 1902, i, 347), and bromo- maltose liepta-acetate, m. p. 112— 113°, [ajg +180-1°, obtained crystalline with great difficulty (cf. Fischer and Armstrong, A., 1902, i, 746), is described in detail.

The specific rotations of these derivatives of a-bioses, unlike those of the P-bioses (cf. A., 1928, 157), show agreement with the regular relationship observed

914 BRITISH CHEMICAL ABSTRACTS.— A.

among the corresponding derivatives of the monose sugars. This difference in behaviour is explained by means of models which show that, under certain conditions, the oxide rings of (3-bioses may face one another, bringing the halogen atoms under the influence of secondary valencies proceeding from the opposite ring, whereas with a-bioses this is impossible.

The models also give formulae for cellulose and cello- biose in agreement with their chemical properties and X-ray diffraction spectra. H. E. F. No t t o n.

C on stitu tion of n odak en in, a n ew g lu c o sid e fr o m P eu ced a n u m d e c tirsiv iim , M a x im . II. J.

Ar i m a (Bull. Chem. Soc. Japan, 1929, 4 , 113—119).—

Nodakenetin (A., 1927, 599; this vol., 430) treated with bromine in chloroform gives a ôrcwio-derivative, m. p. 230—231°, converted by alcoholic potassium hydroxide into nodahilic acid, C13H1303-C0 2H ,H20, m. p. 214— 215° (methyl ester, m. p. 133— 134°) ; the acid is considered analogous to coumarilic acid.

Nodakenetin is oxidised by boiling aqueous chromic acid to 7 - hydroxy co umarin-6- carbozylic acid, m. p.

244—246° (decomp.) to 260—261° (decomp.) (accord­

ing to rate of heating), identified by decarboxylation to umbelliferone, and synthesised by the interaction of 4-resorcylic acid and malic acid in sulphuric acid;

methyl 1-methoxycoumarin-Q-carboxylate, m. p. 165—

166°, is prepared from degradation and synthetical

products. E. W. W iq n a ll.

C on stitu tion of sin istr in . H. H. Sch lx jba c h

and W. Fl o k s h e im (Ber., 1929, 6 2 , j\B], 1491— 1493).

— Extraction of the fresh bulbs of Scilla m aritim a with cold water followed by treatment of the extracts with lead acetate and fractional precipitation with alcohol permits the isolation of sinistrin B , (C6H10O5)4, [a]“

—30-6° in water, and sinistrin A , (C0H10O5)2, [a]“

—25-3° in water. The last-named substance is con­

verted by methyl sulphate and alkali hydroxide into a compound closely resembling methylinulin and con­

verted by oxalic acid into 3 : 4 : 6-trimethylfructose- (2 : 5 ) (cf. Schlubach and Eisner, this vol., 51 ; Haworth and Learner, A., 1928, 510). Sinistrin B appears to be a tetrafructose anhydride.

H. Wr e n. S ta rch . II. P o ta to starch . K. He s sand F. A.

Sm it h (Ber., 1929, 6 2 , [B], 1619— 1626; cf. 1928, 1225).—The influence of pre-treatment of starch with pyridine on its acétylation depends on the induced swelling of the starch for which the water contont of both materials is responsible. Dry starch does not swell in anhydrous pyridine. The ease of acétylation increases with increased degree of swelling. The isolation by Brigl and Schinle (this vol., 299) by the author’s process (loc. cit.) of a starch acetate “ rapidly ” soluble in chloroform to a homogeneous viscous solution has led to a repetition of the work with varied amounts of pyridine and acetic anhydride, whereby readily soluble products are not obtained; under similar conditions amylose affords a freely soluble acetate corresponding with Brigl and Schinle’s starch acetate. Treatment of starch with warm water below the swelling temperature causes layer-wise dissolution without altering the microscopic appearance of the granules except in regard to diameter. Tho aqueous solution yields preparations with the properties of

starch amylose when treated with alcohol. Prolonged treatment of a fraction thus obtained with boihng water causes increased reducing power and diminished optical activity, whilst the solution becomes markedly more acidic. Treatment of natural starch with warm water causes an irregular development of acidity in the solvent which is not apparently related to the amount of carbohydrate yielded to the water in tho corresponding period.

In contrast to natural starch, the product regener­

ated from starch acetate by hydrolysis with methyl- alcoholic ammonia can be dissolved only with difficulty in cold iV-sodium hydroxide. Comparison of the optical activities of solutions of the product and natural starch (prepared by protracted heating with 0-81IV-alkali at 60°) appears to confirm the identity of the substances. The specific rotation of natural starch in solutions of differing concentration with respect to carbohydrate and sodium hydroxide is

tabulated. H. Wr e n.

N e w se r ie s of sta rch d ep o ly m erisa tio n pro­

d u cts. A. Pic t e t and H. Vo g e l (Helv. Chim. Acta, 1929, 1 2 , 700—713).—B y heating dry starch with 3 parts of dry glycerol at 220° followed by dilution with alcohol etc. isotrihexosan, (C6H10O5)s, m. p. 260—

262° (decomp., after colouring at 235°), [a]D +166-5°

in water, was obtained. I t gave the starch-iodine test, and did not reduce Fehling’s solution or aqueous potassium permanganate; when warmed with hydro­

chloric acid it was converted into dextrose. I t was unattacked by emulsin but malt-diastase gave dextrinose. Boihng acetic anhydride produced a monoacetate, m. p. 156— 160°, decomp. 200°, [a]D + 154-8° in chloroform, notcoloured by iodine; hydro­

lysis by sodium methoxide caused regeneration of iso- trihexosan.

tsoTrihexosan when treated with concentrated hydrochloric acid under cooling formed isotrihexose, C18H32O10, decomp. 155—160°, [a]D + 102-1° in water (iosazone, m. p. 169—170°, decomp. 180°), which reduced Fehling’s solution but was not coloured by iodine. Treatment by warm dilute aqueous oxalic acid led to a mixture of dextrose and dextrinose (cf.

Syniewski, A., 1900, i, 79), m. p. 67— 68°, decomp.

200° (Syniewski gave m. p. 82— 85°) [monohydrate, m. p. 94—96°, decomp. 200°; osazone, m. p. 167° (lit.

152—153°); octa-acetate, m. p. 157° (identical with maltose octa-acetate, m. p. 158°)].

isoTriheyosan was further depolymerised by heating with glycerol at 240°, when the dihexosan dcxtrinosan, (CcH10O5)2, m. p. 185—186° (decomp.), [a]D +151-0°

in water (hexa-acetate, m. p. 140— 143°, [a]D +145-5°

in chloroform), was formed. Iodine coloured dextrin- osan a reddish-brown, whilst concentrated hydro­

chloric acid at the ordinary temperature converted it into dextrinose (above). An attem pt to reverse the last change by heating dextrinose at 175° under 12 mm. pressure led only to a substance, in. p. 130—140°,

chloric acid at the ordinary temperature converted it into dextrinose (above). An attem pt to reverse the last change by heating dextrinose at 175° under 12 mm. pressure led only to a substance, in. p. 130—140°,

W dokumencie British Chemical Abstracts. A. Pure Chemistry, August (Stron 53-61)