Action of dilute sulfuric acid on D -fructose

96

NOTES

Anal. Calc. for C&H18N2010: N, 6.3_.

C, 53.8; H, 4.1; N, 6.3. Found: C, 53.9; H, 4.1;

This ester (0.25 g) was dissolved in 80% acetic acid (20 ml) and the solution was boiled under reflux. The hydrolysis was followed by observing the optical rotation (r-dm tube): [a]: - I. IO (initial) + -0.16’ (8 h of refluxing)).Thesolutionwascooled and after having been kept for several h deposited a crop of crystals; recrystallization from benzene, and then from absolute ethanol,

m-p. and mixed m_p.5 2oo-202°. Anal. Calc. for C, 8H16N201 o: C,

51.4;

gave I,4-di-0-p-nitrobenzoyl

H, 3.8; N, 6.7. Found:

erythritol

C, 51.6;

H, 3.8;

N, 6.5. J. W. VAN CLEW

Northern Regional Research Laboratory*

C. E. F&ST

Peoria, Illinois 61604 (U. S. A.) REFERENCES I C. E. BALLOU, J. Am. Chum. SOL, 82 (1960) 2585. 2 J. M. SUGIHARA, Adcan. Carbohydrate C&m., 8 (1953) 3; H. 0. BOUVENG. B. 0. THEANDER, Actu Chem. Scand., I I (1957) 1788. 3 J. hf. SUGIHARA, Adran. Carbohydrate Chem., 8 (1953) 5. 4 R. BARKERAND D. L. MACDONALD. J. Am. Chem. Sot., 82 (1960) 2302. 5 F. Shims AND J. W. VAN CLEVE, J. Am. Chem. Sot., 77 (1955) 3659. (Received September rst, 1966; in revised form, November

LINDBERG, AND

7th, 1966)

*This is a laboratory of the Northern Utilization Research and Development Research Service, U. S. Department of Agriculture.

Division, Agricultural

Carbohyd. Res., 4 (1967) 95-96

Action

of dilute

sulfuric

acid on D-fructose

The modern literature records no study of the action on D-fructose of dilute sulfuric acid, a reagent often utilized for the hydrolysis of polysaccharides. In 1886, Conrad and Guthzeit’ found that D-fructose is decomposed into levulinic acid, formic acid and humin by heating with 10% hydrochloric acid or 10% sulfuric acid. Wohl’ discovered 5-(hydroxymethyl)-2-furaldehyde in the decomposition products formed when n-fructose is warmed with dilute hydrochloric acid. The products obtained by prolonged refluxing of D-fructose with 10% sulfuric acid tie now shown to be a brownish black, water-insoluble product (ca. 11.4%) that during the process of refluxing, and nonvolatile, water-soluble products (ca. 69 %) from which levulinic acid (2,4dinitrophenyl)hydrazone. conld be isolated. separates

Carbohjd. Res.; 4 (1967) 96-98

NOTES

97

The rest of the products (ca. 19.6%) were volatile and contained 5.6% of acetone, determined according to Messinger and Huppert3 and identified by its i.r. spectrum

and by conversion into its (2&iinitrophe~yl)hydrazone,

and 9% of carbon dioxide,

as determined by precipitation as barium carbonate. EXPERIMENTAL

A solution of D-fructose (10.0 g) in 500 ml of 10% sulfuric acid in a flask connected to a distilling apparatus was boiled over a direct flame, and the volume of the solution was kept nearly constant by dropwise addition of distilled water. A test of the distillate with barium hydroxide solution showed that carbon dioxide was present, and the iodoform test was positive until the elapse of 35 h, when it was negative (and the volume of the distillate was ca. 10 1). The mixture in the distilling flask (500 ml) was filtered, giving a brownish black, amorphous substance (1.14 g, 1 l-4%), insoluble in ether, but soluble in alkali. Half of the filtrate (250 ml) was treated with barium carbonate, to neutralize the sulfuric acid present, and the neutral solution was evaporated. The residue (3.45 g, 69%) was partially soluble in ether, and it gave a negative Seliwanoff test, and positive Fehling, ammoniacal silver nitrate, and (2,4-dinitrophenyl)hydrazine tests. The other half of the filtrate (250 ml) was treated with (2+dinitrophenyl)hydrazine reagent* affording a heavy, yellow precipitate that was altered off, and fractionally recrystallized to give a yellow, crystalline material (50 mg), m. p. and mixed m. p. with levulinic acid (2,4_dinitrophenyl)hydrazone, 206”. ?dent@ation of acetone. - The distillate gave positive Legal and iodoform tests. It was therefore treated with (2,Pdinitrophenyl)hydrazine reagent*. The yellowish red precipitate that separated (0.6 g) was filtered off after 24 h, and the filtrate was extracted several times with benzene. The extract was washed with water until neutral, and evaporated to dryness under diminished pressure at 50”; yield, 0.1 g. The yellowish red precipitate and the benzene extract were combined, diluted with benzene, and the solution chromatographed on aluminum oxide, with petroleum ether (b-p. 60-80’7 as the mobile phase.Two main bands separated, the lower of which was eluted with petroleum ether to give a yellow, crystalline material. Recrystallization from ethanol gave acetone (2,4-dinitrophenyl)hydrazone (30 mg), m. p. and mixed m.p. 128”. Its i.r. spectrum was identical with that of an authentic sample. The upper band, eluted with benzene, gave an orange mixture that is still under investigation. Determination of acetone. - A solution of D-fructose (1 .O g) in 30 ml of 10% sulfuric acid was treated as before for 35 h. The volume of the distillate collected was 500 ml. In two separate determinations, the acetone content of the total solution was 5.62 and 5.52%. *Prepared by dissolving 0.25 g of (2,4-dinitrophenyl)hydrazine in 50 ml of water and 42 ml of concentrated hydrochloricacid, by warmingon the waterbath, cooling,and diluting the clear solution to 250 ml tith distilled water.

Carbohpi. Res., 4 (1967) 96-98

98

NOTJZS

In a repetition of the preceding experiDetermination of carbon dioxide. ment, the distillate was trapped in 150 ml of 0.1~ barium hydroxide, and air, free from carbon dioxide, was passed through the distilling apparatus for 35 h. The baryta solution, which had become turbid, was then filtered quickly. The precipitate was dried to constant weight (0.392 g). The content of carbon dioxide was found to be 8.7%. ACKNOwLEDGMENT The author thanks Professor H. El Khadem for hi interest and for the infrared measurements. EL S. AMIN

Faculty of Science,

Alexandria University, Alexandria (U. A. R.) REFERENCES 1 M.c!oANDM. GUTHZEIT. Ber.. 19 (1886) 2569.2572,2847. 2 A. WOIIL,Ber., 23 (1890) 2095. 3 J. MESSMGER AND K. H. HUPPHRT, An&se des Hums, A. G. Verlag, Ziirich, Switzerland, (1898)

760. (Received October llth,

1966; in revised form, November 14th, 1966)

Curbohyd. Res., 4 (1967) 96-98

Complexes of amylose with halogen-substituted diffraction results for wet precipitates

hydrocarbons :

Diffraction diagrams of the dried precipitates obtained by treatment of aqueous solutions of amylose with tert-butyl alcohol’ or isopropyl alcohol2 can readily be indexed. A simple, pseudohexagonal unit exists, which can be accounted for by a close-packed arrangement of he&es having seven D-glucose residues per helix tuml. The structure of the helix is similar to that found in “V” amylose, but expanded or enlarged by one D-glucose residue per helix turn. Powder patterns of wet precipitates formed from various branched-chain alcohol molecules with amylose are indistinguishable among themselves3, and are considerably more detailed2-4. Optical examinationbymicroscopehas shownthat crystals of amylose with certain halogen-substituted hydrocarbons exhibit the same crystal habit as do the amylose-branched-chain alcohol adduct? l 6. The following X-ray examination of the addition product of amylose with several halogen-substituted hydrocarbons was undertaken to characterize these subst&c& more fully. Dif%action spectra of complexes containing bromine and chlorine Clzrboiyd. Res., 4 (1967) 98-101