[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.