[Agr. Biol. Chem., Vol.27, No.10, p.689•`694, 1963]

Studies on the D-Xylose Series

Part I. Syntheses of 3-Acylamino-3,5-dideoxy-D-xylofuranose and Its Derivatives

By Hiroshi KUZUHARA and Sakae EMOTO

The Institute of Physical and Chemical Research, Tokyo Received June 20, 1963

Methyl 3-acetamido-3, 5-dideoxy-D-xylofuranosides (VIIIa, VIIIb) were prepared from D-

xylose. The glycoside linkage of ƒ¿-anomer (VIIIa) was more easily hydrolyzed to 3-acetamido-

3, 5-dideoxy-D-xylose (X) by acid than that of ƒÀ-anomer (VIIIb). Reduction of X gave 3-ace- tamido-3, 5-dideoxy-D-xylitol (XIV), which was hygroscopic syrup.

D-Xylose is obtained by hydrolysis of xylan L-threonine, one of the essential amino acids, which occurs in practically all land-plantslo. from them. Preparation of the optically active Because of wide botanical distribution and amino acid from the sugar derivatives are in abundance of xylan, D-xylose is one of the progress and will be noted in the following most obtainable sugars. In practice, D-xylose report. is prepared by hydrolysis of agricultural re- P.A.Levene and J. Compton3) prepared sidues such as corn cobs, cotton-seed hulls and 1, 2-O-isoplopylidene-5-deoxy-D-xylofuranose wheat straws. In spite of its abundance and (II) from 1, 2-O-isopropylidene-D-xylofuranose cheapness, D-xylose has no usefulness except (I) through three steps. its conversion to furfral. We mesylated II to 3-O-methanesulfonate In this series of paper, we will describe attempts of syntheses of useful matter by (III) which was converted by acetolysis to 1, 2-di-O-acetyl-3-O-mesyl-5-deoxy-D-xylofura- utilizing asymmetric carbons of D-xylose and nose (IV). Treatment of IV with 1% discuss various steric problems accompanying methanolic hydrogen chloride yielded syrupy with it. methyl 3-O-mesyl-5-deoxy-D-xylofuranoside (V) One of the authors and M. Matsui2) re- which partly crystallized on standing. Cry- ported previously that 2-benzamido-2-deoxy-L- stalline part was ascertained to be ƒÀ-anomer glyceraldehyde, obtained from 2-benzamido-2- deoxy-D-glucitol (N-benzoyl-D-glucosaminol) by (Vb) from [ƒ¿]D-values of itself and of the subsequent reaction-products. Syrupy residue cleavage at the 3,4-position with sodium meta- was probably ƒ¿-anomer (Va), contaminated periodate, was oxidized to N-benzoyl-L-serine. with a small amount of ƒÀ-anomer. The fact Now we report syntheses of 3-acetamido-3,5- that ƒÀ-anomer of 3-O-sulfonyl-D-xylofuranoside dideoxy-D-xylose (X) and its reduction prod- crystallizes easily than ƒ¿-anomer, had been uct (XIV) with the purpose of preparing also reported in the case of 5-O-methyl-3-O 1) C.S. Hudson and S.M.Cantor, "Advances in Carbohydrate Che- tosyl-D-xylofuranoside by G.J. Robertson and mistry," Vol.5, Academic Press Inc., Publishers, 1950, p.269. 2) H. Kuzuhara and M. Matsui, J. Agr. Chem. Soc. Japan, 34, 404 1960). ( 3) P.A. Levene and J. Compton, J. Biol. Chem. 111, 325 (1935). 690 Hiroyoshi KUZUHARA and Sakae EMOTO

FIG. 1.

D. Ga114). that of the latter was -153•‹. Pang Chang Syrupy Va and crystalline Vb were con- and Yuoh-Ting Lu5) had prepared through

verted to corresponding 2, 3-anhydro-ribosides another process only ƒÀ-anomer (VIb) of which

(VIa) and (VIb) respectively with an equiva- [ƒ¿]D-value had been noted to be -113.5•‹. lent sodium methylate. Both VIa and VIb Ammonolysis of VIa and VIb gave crystal- were crystals of low melting point, 23•Ž and line ƒ¿-aminoglycoside (VIIa) and syrupy ƒÀ- 3•Ž; [ƒ¿]D-value of the former was +26•‹ and 5) Pang Chang and Yuoh-Ting Lu, Hua Hsfieh Hsiieh Pao, 23, 169 4) G.J. Robertson and D. Gall, J. Chem. Soc., 1937, 1600. (1957); C.A., 52, 16220 (1958). Studies on the D-Xylose Series 691

anomer (VIIb). D-glucopyranose as A.B. Foster et al.13) noted Opening of the epoxide ring of 2, 3-anhydro- previously. pentofuranoside by nucleophilic reagents has On the other hand, the aldofuranosides are resulted in nearly exclusive attack at position- hydrolyzed from 50 to 200 times more rapidly 3 in all cases previously studied6-10). Thus, than the corresponding aldopyranosides14). VIIa and VIIb were expected to be methyl Thus C.D. Anderson et al.12) reported that 3-amino-3, 5-dideoxy-ƒ¿-D-xylofuranoside and its methyl 3-acetamido-2, 3-dideoxy-5-O-trytyl-ƒÀ-D-

-anomer. Though ƒ¿-anomer crystallized veryƒÀ ribofuranoside was hydrolyzed at 100•Ž to easily, ƒÀ-anomer did not crystallize after all. 3-acetamido-2, 3-dideoxy-D-ribose in 80% aque- The fact is contrast to the case of Va and Vb. ous acetic acid. Acetylation and benzoylation of VIIa in Methyl 3-acetamido-3, 5-dideoxy-ƒ¿-D-xyloside water gave corresponding N-acyl derivatives, (VIIIa) was also hydrolyzed perfectly by (Villa) and (IX), in good yield. Syrupy keeping at 80•Ž for an hour in 80% aqueous VIIb gave also crystalline N-acetyl compound acetic acid. Yielded syrupy X was identified

(VIIIb). by preparing its crystalline ƒÏ-nitrophenylhy- In the other preparation of 3-acetamido-3, 5- drazone (XII). N-Benzoyl derivative (IX) dideoxy-D-xylose (X), as shown in Fig.2, the was also changed into 3-benzamido-3, 5-dide-

hydrolysis of VIIa to 3-amino-3, 5-dideoxy-D- oxy-D-xylose (XI). xylofuranose hydrochloride (XVIII) gave On the contrary, the ƒÀ-anomer of VIII brown syrupy product which was not purified. (VIIIb) resisted hydrolysis under the above When impure XVIII was neutralized with condition. Under the more drastic condition sodium methylate for the subsequent acetyla- (refluxing in 80% aqueous acetic acid for 3 tion, partial decomposition seemed to occur hours), it gave positive Benedict test for re- because of the alkaline instability of 3-amino- ducing sugar, but did not give crystalline ƒÏ- 3-deoxy-sugars11,12). nitrophenylhydrazone. Hydrolysis with Am- berlite IR-120 (H form, 25ml in 100ml of water) at 70•Ž gave the same result. Namely, imperfect hydrolysis seemed to occur under these conditions. Hydrogenation of X yielded the correspond- ing N-acyl-aminopolyol (XIV), which was

FIG.2. hygroscopic syrup. Acetylation of XIV with acetic anhydride-pyridine gave colorless syrupy Generally stability of amide-linkage to acid triacetate (XV). is stronger than that of glycoside-linkage even in pyranoside. Thus the greater part of EXPERIMENTAL methyl 2-acetamido-2-deoxy-D-glucopyranoside All melting points were uncorrected. Low melting was hydrolyzed through 2-acetamido-2-deoxy- point of VIb was measured as follows. In a capillary tube fastened to a thermometer, the liquid sample was 6) B.R. Baker and R.E. Schaub, J. Am. Chem. Soe., 77, 5900 (1955), 7) B.R. Baker, R.E. Schaub and J.H. Williams, ibid., 77, 7 (1955). placed and cooled in an ice-salt bath in order to be 8) J.M. Anderson and E. Percival, J. Chem. Soc., 1956, 819. solidified. Then the capillary was removed from an 9) J. Davoll, B. Lythgoe and S. Trippett, ibid., 1951, 2230. ice bath and the temperature at which the sample 10) C.D. Anderson, L. Goodman and B.R. Baker, J. Am. Chem. Soc., 80, 5247 (1958). remelted was observed. 11) E.H. Flynn, M.V. Sigal, Jr., P.F. Wiley and K. Gerzon, ibid., 76, 3121 (1954). 13) A.B. Foster, D. Horton and M. Stacey, J. Chem. Soc., 1957, 81. 12) C.D. Anderson, W.W. Lee, L. Goodman and B.R. Baker, ibid., 141 W. Pigman "The Carbohydrates", Academic Press Inc., Pub- 83, 1900 (1961). lishers, 1957, p.211. 692 Hiroyoshi KUZUHARA and Sakae EMOTO

ƒËkBr 1,2-O-Isopropylidene-3-O-mesyl-5-deoxy-D-xylofura- : 3460cm-1 (OH) 1360, 1180cm-1 (sulfonate).

nose (III). To a solution of 2.6g of 1,2-O-isopropyli- It was clear from the subsequent reaction-product

dene-5-deoxy-D-xylose (II) in 30ml of dry pyridine, that the greater part of the syrup was ƒ¿-glucoside (Va)

cooled in an ice bath, was added 2.1g of methanesul- containing a little ƒÀ-anomer. Anal. Found: C, 36.85; fonyl chloride. The mixture was let stand in a H, 6.35; S, 13.16. Calcd. for C7H14O6S: C, 37.16; H, refrigerator for 16 hr. and then at room temperature 6.19; S, 14.15%. ƒËmax: 3540 cm-1 (OH), 1360, for 24 hr., and diluted with a small volume of water. 1180cm-1 (sulfonate). After 2 hr. the mixture was poured into water and Methyl 2,3-anhydro-5-deoxy-D-ribofuranoside. extracted with chloroform. The extract, washed with A. ƒ¿-Anomer (VIa) To an ice-cold solution of enough 5% ice-cold sulfuric acid and then twice with 10.8g of syrupy Va in 30ml of methanol was added water, was dried over magnesium sulfate and evapo- an ice-cold solution of 1.1g of sodium in 30ml of rated in vacuo to the thick syrup (3.6g). It was methanol. The mixture was left to stand in a refrige- dissolved in 30 ml of methanol, treated with charcoal, rator for 4days, and filtered. The insoluble materials and evaporated to dryness. When the resulted syrup were washed with methanol. The combined filtrate was allowed to stand at room temperature for a few and washings were adjusted with glacial acetic add days, it crystallized. Yield, 3.4g (90%). M.p.49•` to pH5.4, then evaporated to dryness in vacuo. The 51•Ž; [ƒ¿]21D=-10.3•‹ (in chloroform, c=3.5); Anal. residue was extracted with 200ml of chloroform and Found: C, 42.51; H, 6.30; S, 11.35, Calcd. for washed with water. After being dried over magnesium C9H16O6S: C, 42.85; H, 6.34; S, 12.30%. sulfate, the extract was evaporated in vacuo and re-

1,2-Di-O-acetyl-3-O-mesyl-5-deoxy-D-xylofuranose sidual syrup was distilled through a condenser chilled with ice-cold water. The greater part of the syrup (IV). To a stirred solution of 41g of III in 720ml of acetic acid and 84ml of acetic anhydride was added distilled off at 42•`44•Ž (3mmHg). The distillate dorpwise 43ml of concentrated sulfuric acid with crystallized immediately when it was placed in an ice-

water-cooling below 20•Ž. After standing at room salt bath. Yield, 3.2g (52%). M.p.21•`23•Ž; [ƒ¿]17D

temperature for 20hrs., the solution was poured onto 26•‹ (in methanol, c=1.36); Anal. Found: C, 54.87;+

2500g of ice, then extracted with 2l of chloroform. H, 7.67. Calcd. for C6H10O3: C, 55.37; H, 7.75%.

The extract, washed with saturated aqueous sodium max: 848cm-1 (epoxide). ƒË bicarbonate and then with water, was dried over B. ƒÀ-Anomer (VIb): Treatment of 10g of Vb in magnesium sulfate and evaporated to dryness in vacuo, 100ml of methanol with 1g of sodium in 30ml of

yielding 49 g of pale yellow syrup (107%). It is methanol, as described in preparation (A) above, gave suitable for the subsequent reaction. A part of the 2.2g (38%) of VIb. B.p.20•`23•Ž (3mmHg). It syrup, dissolved in methanol, was treated with char- crystallized also in an ice-salt bath. M.p.2•`3•Ž; coal and evaporated to dryness. Resulted colourless -153.4•‹ (in methanol, c=2.49): Anal.[ƒ¿]16D Found: syrup was used for the infra-red spectrum. ƒËmax: C, 55.28; H, 7.71. Calcd. for C6H10O3: C, 55.37; H 1750cm-1 (C=O of acetate) 1180, 1360cm-1 (sulfon- 7.75%. ƒËmax: 850cm-1 (epoxide). ate). Methyl 3-amino-3,5-dideoxy-D-xylofuranoside. Methyl 3-O-mesy1-5-deoxy-D-xylofuranoside(Va and Vb) A. ƒ¿-Anomer (Vila): A solution of 3.2g of VIa A solution of 29g of IV in 600g of 1% methanolic in 60ml of concentrated ammonium hydroxide was hydrogen chloride was allowed to stand in a stoppered heated in an autoclave at 100•Ž for 8hr. After flask for 20hr. at room temperature, then neutralized addition of 60ml of water, the solution was treated by the portionwise addition of 40g of sodium bi- with charcoal, filtered, then evaporated in vacuo. To carbonate. The filtrate was evaporated in vacuo. The the residual syrup was added 150ml of benzene, and residue was extracted with 500ml of chloroform and the mixture was evaporated in vacuo, yielding 3.6g the extract was evaporated in vacuo, yielding 12.8g of of crystal (quantitative yield). Recrystallization from

syrup and 11g of crystal. The crystal was ƒÀ-glucoside ethyl acetate gave white leaflets which gave positive

(Vb). M.p.101•`102•Ž; [ƒ¿]18D=-64.5•‹ (in methanol, ninhydrin test. M.p.122•`123•Ž; [ƒ¿]23D=+126•‹ (in

c=2.23); Anal. Found: C, 37.19; H, 6.32; S, 13.72. water, c=1.34); Anal. Found: C, 49.20; H, 8.55; N,

Calcd. for C7H14O6S: C, 37.16; H, 6.19; S, 14.15%. 9.38. Calcd. for C6H13O3N: C, 48.96; H, 8.90; N, 9.5%.

max Studies on the D-Xylose Series 693

ƒËkBrmax 3400 to stand at 40•Ž for 10 minutes and then extracted , 3210, 3120cm-1 (NH2, OH) , 1630cm-1 twice with 100ml of chloroform. After having been (NH2). washed with water, combined extracts were dried with B. ƒÀ-Anomer (VIIb): Treatment of 2.5g of VIb magnesium sulfate and evaporated in vacuo to yield with 50ml of concentrated ammonium hydroxide, as 5.5g (92%) of amorphous product. Recrystallization described in preparation (A) above, gave 2.6g of from methanol was unsuccessful. Recrystallization ninhydrin-positive syrupy product which did not from ethyl acetate gave white product of m.p. 147•Ž. crystallize. It was confirmed by subsequently de- [ƒ¿]12D=+125•‹ (in chloroform, c=0.60) ; Anal. Found: scribed N-acylation that the greater part of the syrupy C, 62.04; H, 6.62; N, 5.54. Calcd. for C13H17O4N: product was VIIb. C, 62.14; H, 6.82; N, 5.57%. Methyl 3-acetamido-3, 5-dideoxy-n-xylofuranoside. 3-Acetamido-3, 5-dideoxy-n-xylofuranose (X) and its A. ƒ¿-Anomer (VIIIa). To a solution of 850mg of p-nitrophenylhydrazone (XII). A solution of 4.2g of VIIa in 5ml of water, cooled in an ice bath, was VIIIa in 200ml of 80% aqueous acetic acid was heated added 1 g of acetic anhydride. After having been at 80•Ž for an hour. After treatment with charcoal, stirred at 0•Ž for 5 minutes and allowed to stand at the solution was evaporated in vacuo to yield 4.1g room temperature for an hour, the mixture was eva- (105%) of brown syrup (X) which gave a positive porated in vacuo, yielding 1g (90%) of crystal which Benedict test for a reducing sugar on heating. To a gave negative ninhydrin test. Recrystallization from a solution of 190mg of syrupy X in a small volume of small volume of methanol gave colourless crystals of water was added 180mg p-nitrophenylhydrazine in m.p. 157•`158•Ž. [ƒ¿]22D=+76.4•‹ (in methanol, c= 4ml of 50% aqueous acetic acid. The mixture was 2.19)'; Anal. Found: F, 50.70; H, 8.04; N, 7.38. Calcd. allowed to stand at room temperature for 16 hr. for C8H15O4N: C, 50.78; H, 7.99; N, 7.40%. ƒËkBrmax: Separated crystals were filtered and recrystallized twice 3360cm-1 (NH, OH), 1650cm-1 (amide C=O), 1560 from a small volume of methanol to yield 200mg cm-1 (amide NH) . (61%) of orange-colored crystals. They showed a B. ƒÀ-Anomer (VIIIb). To a solution of 2.6g of broad melting point 107•`116•Ž, because the recrystal-

syrupy VIIb in 30ml of water, cooled in an ice bath, lization was rather difficult. Anal. Found: C, 49.95; was added 3.0g of acetic anhydride. The mixture H, 5.81; N, 17.57. Calcd. for C13H18O5N4: C, 50.31; H, was stirred at 0•Ž for 5 minutes, let stand 5.85; N, 18.06%. room temperature for 70 minutes, and evaporated 3-Benzamido-3, 5-dideoxy-n-xylofuranose (XI) and its in vacuo to yield 3.4g of pale yellow syrup which p-nitrophenylhydrazone (XIII). A solution of 1.5g of did not crystallize in spite of treatment with char- IX in 100ml of 80% aqueous acetic acid was heated coal in methanol. Then, a solution of the syrup at 80•Ž for an hour. After treatment of charcoal, in 160ml of glacial acetic acid and 40ml of water the solution was evaporated in vacuo to yield 1.2g was heated at 65•Ž for 40 minutes. The mixture was of amorphous XI which gave a positive test with evaporated to dryness in vacuo and resulting residue Benedict's solution on heating. To a solution of was dissolved in ethyl acetate. After filtration of in- 500mg of XI in 4ml of 50% aqueous acetic acid was soluble matter, the filtrate was dried with magnesium added 350mg of p-nitrophenylhydrazine in 14ml of sulfate and evaporated in vacuo to yield 2.0g (60% 50% aqueous acetic acid. The mixture was allowed from syrupy VIIb) of crystals. Recrystallization from to stand at room temperature overnight, separating ethyl acetate gave cubic prisms of m.p. 120•`122•Ž. crystals. Careful recrystallization from ethanol gave It gave negative tests with ninhydrin and with Bene- 300mg (38%) of yellow crystals. M.p. 205•`207•Ž dict's reagent. [ƒ¿]17D=-49.2•‹ (in methanol, c=1.81); (decomposition); Anal. Found: C, 57.80; H, 5.14; Anal. Found: C, 50.89; H, 7.61; N, 7.41. Calcd. for N, 14.90. Calcd. for C18H20O5N4: C, 58.06; H, 5.41; N,

C8H15O4N: C, 50.78; H, 7.99; N, 7.40%. 15.05%.

Methyl 3-benzamido-3, 5-dideoxy-ƒ¿-D-xylofuranoside 3-Acetamido-3, 5-dideoxy-n-xylitol (XIV) and 1, 2, 4-

(IX). To a stirred solution of 3.5g of VIIa and 3.5g Tri-O-acetyl-3-acetamido-3, 5-dideoxy-D-xylitol (XV). of sodium carbonate in 100ml of water, cooled in an To an aqueous solution of 4.3g of syrupy X which ice bath, was added dropwise 4.5g of benzoyl chloride. had been dried on sodium hydroxide for elimination

The mixture was stirred at 0•Ž for 2.5 hrs., allowed of acetic acid, was added 2g of Raney nickel and th 694 Hiroyoshi KUZUHARA and Sakae EMOTO

mixture was stirred for a few minutes. After filtration, yield. For elementary analysis the syrup in methanol 3 g of Raney nickel (W-4) was added again to the was treated with charcoal and evaporated in vacuo to filtrate. Then the mixture was hydrogenated at 90•Ž yield colorless syrup.[a]22D=+ 39.5•‹ (in methanol, for 4 hr. in an autoclave. (First hydrogen pressure c=1.19); Anal. Found: C, 50.75; H, 6.87; N, 4.63. was 130 Kg/cm2 at room temperature.) Calcd. for C13H21O7N: C, 51.48; H, 6.98; N, 4.62%.

After filtration of the catalyst, the filtrate was max: 3380 cm-1 (NH), 1740 cm-1 (ester C=O),ƒË treated with hydrogen sulfide. Yielded preciptate was 1670 cm-1 (amide C=O), 1550 cm-1 (amide NH). filtered of and the filtrate was evaporated in vacuo, Acknowlegement. The authors wish to ex- resulting in 3.2 g of pale yellow hygroscopic syrup

press their thanks to Dr. Haruo Homma and (XIV). Acetylation of 200 mg of XIV with pyridine- acetic anhydride mixture at room temperature for 16 his co-workers of the Institute of Physical and hr. gave syrupy triacetate (XV) in moderately good Chemical Research for elementary analyses.