The synthesis of D -arcanose

Carbohydrate

284

Research

ElsevlerPubbshmgCompany,Amsterdam Prmtcdm ES&mm

THE SYNTHESIS

OF D-ARCANOSE*

G B HO~..XRTH,W A SZAREK,AND

J K N JOYES

Department of Chemrstry, Qrreeu’s Umversrtv. Kuqston.

Ontarxo (Canada)

(Received December 27th, 1967)

ABSTRACT

Oxldatlon of methyl 4,6-0-benzyhdene-2-deoxy-a-D-lyxo-hexopyranoslde (3) with ruthemum tetroxlde gave the 3-ketone 4 m lugh yield Treatment of ketone 4 with methylmagneslum lodlde gave predommantly methyl 4,6-0-benzyhdene-2deoxy-3-C-methyl-cD-xylo-hexopyranoslde (5), which was converted mto the 3-0methyl denvative (6) The reactlon of compound 6 wth 1V-bromosucclmmlde afforded methyl 4-O-benzoyl-6-bromo-2,6-d~deoxy-3-C-methyl-3-O-methyl-~-~-~~Zo-hexopyranoslde (7) m high yield Compound 7 was converted, by catalytic debenzoylatron and reductive debrommatlon, mto methyl a-D-arcanosrde(9). Acid-catalyzed hydrolysis of glycoslde 9 gave D-arcanose (10)Configurational studies support the 2,6-dldeoxy3-C-methyl-3-0-methyl-\ylo-hexose structure for arcanose INTRODUCTION

Lankamycm, a relatively new medmm-spectrum antlblotlc, active agamst gram-positive bacteria, 1s produced, together with another antlblotlc, lankacldm, by Streptomyces tloiaceomger’, a micro-organism Isolated from a sample of sod m Ceylon Acid hydrolysis of lankamycm, which belongs to the macrohde group’, g!ves two sugar components, namely, lankavose (4,6-dldeoxy-3-0-methyl-D-_uyZohexose), and the 4-0-acetyl derlvatlve of a new branched-cham sugar, arcanose3 4 By a combmatlon of n m r and degradatlve studies, the 2,6-dldeoxy-3-C-methyl-30-methyl-L-_\>rZo-hexosestructure I was proposed for arcanose The structure was supported further by conversions of L-arcanose mto the dlastereolsomer, L-cladmose, by a simple oxldatlon-reduction process at C-4 RESULTS AND DISCUSSION

In contmuation of our syntheses of branched-cham sugars, we have now prepared D-arcanose by a route sunxlar to that employed6 m the synthesis of L-mycarose (2,6-dldeoxy-3-C-methyl-L-rrbo-hexose) and L-cladmose (2,6-dldeoxy-3-C-methyl-3*For a prehmmary commumcatlon, Carbohvd

Res , 7 (1968) 284-290

see Ref

1

289

SYNTHESISOFD-ARCANOSE

6 79 (3-proton 7

smglets, C-l

OMe

and C-3 OMe),

t 8 8 (3-proton

smglet,

C-3 Me),

8 8 (3-proton doublet, J 6 5 Hz, C-5 Me) Anal CaIc for &H,,O, C, 56 8, H, 9 5 Found

C, 56 6, H, 9 3 2,6-DIneo_~~-3-C-merhyl-3-O-methyl-D-xylo-~e_K~~e (D-arcanose) (10)- MethI 1 a-D-arcanoslde (9) (177 mg) m water (2 5 ml) was stu-red with Rexyn-101 resm (H+) for 4 h The fiitered sol&on was passed through a small column of Duohte A-4 resin (OH-) to remove any trace of acid Concentration of the solution gave a colorless syrup which crystalhzed on trlturafion with ether Recrystallization from ethyl acetate-petroleum ether (b p 60-80”) gave D-arcanosc (10)as pnsms, yield 55 mg (31%), m p IOl-102”, [z]~ +19 8” (c 1 0, ethanol), Jzi 2 93 pm (OH), n m r data ? 6 81 (3-proton singlet, C-3 OMe) r 8 78 (3-proton singlet, C-3 Me), z 8 78 @-proton doublet, J 6 5 Hz, C-5 Me), ht 3 for L-arcanose, m p 96-98”, [a]n - 19 2” (c 4 6, ethanol) The mfrared and n m r spectra of the synthetic product were identical with those of authentic r_-arcanose The two compounds were mdlstmgmshable by 3 I (solvent A), 1.42 (solvent B), and 1 98 paper chromatography and had RRhn (solvent C) Anal Calc for CsH,,04 C, 54 5, H, 9 1 Found C, 54 7, H, 9 1 Methyl3-0-acetyl-4,6-0-benz~~~tdene-2-deouy-3-C-methyC-cr-D-xylo-he~opyranosjde - To a solutlon of compound 5 (190 mg) m NJV-dlmethylamhne (0 41 ml) was added acetyl chloride (0 1 ml), and the mixture was left at room temperature for 1 h and then heated on a steam bath for 4 h The reaction nuxture was poured mto water and extracted with chloroform The extracts were washed with 6~ sulfuric acid, sodium hydrogen carbonate solution, and water, and concentrated to yield a syrup (190 mg), which was chromatographed on slltca gel with 2 3 ethyl acetate-petroleum ether (b p 60-80”) as eluent The 3-0-acetyl derivative was lsoiated as a syrup, R,O75(tlc), /g;z 5 75 (OAc), 13 3, 14 4 ,um (Ph), n m r. data T 2 4-2 8 (S-proton multlplet, Ph), T 4 41 (l-proton singlet, benzyhdene-methme H), 7 6 65 (3-proton smglet, C-l OMe), 7 8 02 (3-proton singlet, OAc), r 8 40 (3-proton singlet, C-3 Me) ACKNOWLEDGMENTS

The authors thank the National Research Council of Canada for financial support of this work, and Dr G Roncan for a generous gift of methyl 4-O-acetylL-arcanoade REFERENCES 1 G B HO~ARTH, W A SZAREK,AND J K N JONES, Chernl Cot11n1ra1,(1968) 62 2 E G.whfANN, R HUTTER,~ KELLER-SCHIERLEIN.L NEIPP,V PRELOG. AND H ZAHNER, H&r Chm Acta, 43 (I 960) 60 I 3 W KELLER-SCHIERLEINAND G ROhCARI, Helc Chrtn Acm,45 (1962) 138 4 W KELLER-SCHIERLEIN AND G RONCARI, Hell> Chmt Acra, 47 (1964) 78 5 G RONCARIAND W KELLER-SCHIERLEIN,Heh Chm Acta,49(1966) 705 6 G B HOWARTH AND J K N JONES, Can J Chrm ,45 (1967) 2253 7 A B FOSTER,~ G OVEREUD,AND M STACEY, L Chem Sot, (1951)974 S B T LAwroh, unpubhshed results Carbobyd

Res , 7 (1968) 284-290

G

290

16

W

A

SZABER. J K N JONES

(1966) COLLINS, P T DOGANGES, AND W G.OVEREND, J Chem sot (0, 1131 E L ELIEL, Stereochemsfry of Carbon Compounds, McGraw-HdI, New York, 1962, p 69 S HANESSIAN, CarbohJd Res, 2 (1966) 86; Adoan CurbhId Chem ,21 (1966) 143 A C RICHARDSONAND K A MCLAUCHLAN,I Chem Soc,(1962)2499 T D NEVIIT AND G S HAMMOND, J Am Chem Sot ,76 (1954) 4124. F W L~CEITEMXUER AND P EMIG, Tefrahedbn Lett , (1967) 577 R J FERRIER,~ G OVEREND, G A RAFFERTY, H M WALL, AND N R WILLIAMS, Proc Chem Sot , (1963) 133, B FLAHERTY, W. G OVEREND, AND N R WILL,-, J Chem Sot (C), (1966) 398 A P MACLENNAN,H M RANDLE,ANDD W SMITH, Anal Chem,31(1959)2020

9 P J. BEYNON,P.M 10 11 12 I3 14 15

B HOWARTH,

Carbohyd

Res ,7

(1968) 284-290