CarbohydrateResearch233( 1992)251-253 ElsevierSciencePublishers8.V.. Amstcdam
251
Note A novelroute to 2-deoxy-2-iodo-o-mannopyranose derivatives Du5an Miljkovid, EvgenijaDjurendii, Nada vukojevid, Katarina GaIi and J6nosCsan6di Instituteof Chemistry,Facultyof Sciences, Ilnircnity of Nori Sa4 21000ttoci Sad(yug&tia) (ReceivedDecember20th. t99l: accepredMarch t3rh. 1992)
1,5-Anhydro-2'deory-o-hex-l-enitolsare versatile synthonsl'2. Various functional groups,suchas chloro3,fluoroa-7,bromos,or iodoe-il, may be introduced at position 2 by either direct or indirect addition of suitable agentsacross the doublebond. Iodination of o-glucal triacetate, using iodine and silver benzoatein dry ben_ zenee'|o, iodine and silver acetate in methanols, N-iodosuccinimide in dry methanolrr,or iodonium bis(2,4,Gtrimethyrpyridine)perchloratel2, havebeen described,correspondingto the formal addition of atkyl or acyl hypoioditeacrossthe double bond. However,the formation of free 2-deory-2-iodosugarshas not been describedhitherto. we now report a formal electrophiricadditionof ,.hypoiodousacid" to 3,4,6-tri13(l) and o'acetyl-o-glucal 3,4-di-o-acegl{-o-tosyl-n-glucalra (2). Dependingon the buffer systemused and the pH, a mixture of the 2-deory-2-iodoesters3 of 5 together,withthe corresponding2-deory-2-iodo sugars4 or 6, or only 4 or 6, were obtained.The compoundsobtainedcould be used for the preparationof 2-deoxy sugarsor Brigl's anhydrides. Thus, treatmentof I or 2 with iodine in rerr-butylatcohol in the presence of acetatebuffer (pH 5, room temperature,3 h) gave a mixture of the 2-deoxy-2iodo'manno'esters 3 or 5 togetherwith the corresponding2-deoxy-2-iodo-a-o-mannopyranosederivatives4 or 6, in .the ratio 3: l. However,when this reactionwas carried out in the presenceof a phosphateor carbonatebuffer (pH 6-7, room temperature,3 h), the 2-deory-2-iodo-a-o-mannopyranose derivatives.l or 6 were the only isolableproducts6o-60vd. The structuresof 3-6 were confirmedby the NMR data(TableI) and [a]o values. The above procedure for the preparationof the 2-deoxy-2-iodo-a-o-mannoCofiespondence to: Dr. D. Miljkovid, Institute of Chemistry.Facultyof Sciences,Universityof Novi Sad, 21000Novi Sad,Yugoslavia. 0008-6215/92/505.00 O 1992- ElsevierSciencePublishers B.V. All rightsreservcd
D. tvlitikocit et a!./ Cartulrydr. Rer 2t1(I99il
?52
251-253
TABLE T NMR datafor 3-6 Compound
tH (6 in pPm,.l in Hz) H-2
H-l
H-3
H-5
H4
H-6a
H-6b
Ac
MdOTs)
2"07s 2.ll s Ll2s 2.17s
4.5Edd It,4 9.2
5.44t
4.20m 4.13-.l.lEm
5.60d r.57dd 4.73dd .f3r 9.5 ILzl.3 tt4.3
5.,t0t
4.28m ,r.5 9'5
4.20m
2.07s 2.10s 2-13s
5.29r
4.16m
4.ll m
2I}6 s 2.09s 1 1 5s
2.45s
4.33m
4.01-1'09m
2.01s 2.07s
2.i14s
CH3CO
cH3CO
6.39d t \21.5
-1.53dd It 4.3
6.28d r.47dd 4.56dd /r.4 9'o .Ir.21.5 I,4.3
,4i 9.0
5.51d r.5l dd 4.69dd 5.1?t '3.r 9'5 It.zl.4 I$4.3 /1{ 9.5 (6 in ppm)
c-3
c4
c-5
c6
6.76
67.63
69.09
62.24
20.65 20.78 20.93
169.64
94.36 26.82 68.48 /c.r.s-r tc-zg.z 158 lE4
67.44
7t.2r
67.88 :1.68
205e 20.83 20.E9
16E.08
[email protected] r69.84
68.57
67.89
68.90
68.36 ll.6l
20.56 2038
169.72 169.87
c-l
c-2
95.71 30.2E
95.72 30.00 tc-z.g.z 159
!te(OTs)
1m.04 171.05
inexpensive pyranose derivatives4 and 6 gives satisfactory yields and involves reagents. cHpR
^.(::-e, Lo
AcO l R = A c 2n =
T:
:tR =
Ac,R'=oAc
l.R =
Ac,R'=oH
5R =
rs,R'=cAc
6 R =
Ts,R'= oH
EXPERIMENTAL
with a Biichi General methods.-Meltingpoints(uncorrected)were determined a Bruker rH with were recorded andr3C NMR spectra The SMP-20appararus. (internal Nle.Si)' AC 250 E instrumenton solutionsin CDCI-.,
D. Miljkodt et d-/Carbohydr. Res.233(t99il 2SI-ZSJ
(3) and 3,4,6-ti-OL,3,4,6-Tetra-O-acetyl-2-deory-2-iodo-a-o-mannopyranose (4').1a) To a solution of I (1.39 g, 5.1 acetyl-2-deory-2-iodo-a-o-mannopyranose mmol) in 8: I tert-butyl alcohol-water (.15rnl-) at rtx)m temperaturewas added a solutionof iodine (4.06 g, 16 mmol) in 2:l tert-butylalcohol-water(45 mL) and acetatebuffer Q7.73e (0.34 mol) of NaOAc and 41.45mL (0.12mol) of HOAcI at pH 5. The mixture was stirred in the dark for 3 h (room temperature) then poured into water (150 mL), neutralised with NaHCOr, illd extracted with ether. The extractswere combined, washed with 0.1 M sodium thiosulfate (50 mL), dried (NarSOa),andconcentrated.Columnchromatography (silicagel;benzene-EtOAc, 19:1) of the syrupyresidue(1.95g, 87.3Vo\ gave3 (1.14g, 48.7Vo), [clo +13. (c 0.5,CHCI3),and 4 (0.293g,13.\Vo\,[o]o -ZO' k 0.2,CHCI3),isolatedascolorless oils. (b) To a solutionof I (0.455g,1.67 mmol) in 8: I tert-butylalcohol-water(20 mL) at room temperature was added a solution of iodine (1.05 g, 4.14 mmol) in 2:l tert-burylalcohol-water(20 mL) at pH 6-7 (phosphatebuffer; NaTHPO*and NaHtPOn, 40 mL, 0.2 M). The mixture was stirred in the dark for 24 h (room temperature),then poured into water (100mL), and extractedwith CHClr. The extracts were combined, washed with 0.1 M sodium thiosulfate (25 mL), dried (Na2SOa),and concentrated.Columnchromatography (benzene-EtOAg 19: l) of the syrupyresidue(0.5589,80.2Vo) gave4 (0.435g, 62.5Vo),isolated as an oil. 1,3,4-Ti-O -acetyl-Z-deory-2-iodo -6-Q-p+oluenesulpho nyl-a-D-mannolryrano se (S\ -2-iodo-6-O-p-tolaenaulphonyl-a-o-mannofo and 3,44i-O-acetyl-2-deory ranose (6\. -(a) Treatmentof 2 (1.96g, 5.1 mmol),asdescribedin (a) for l, gaveS as a synrp (1.55g, 53.3Vo'),lalo+27.5" (c 0.54,CHCI3),and 6 (0.35g L3.0Vo), mp 123-t24" (dec)(from CH2Cl2-hexane),Ialp + 10' (c 0.5,CHCI3). (D) Treatmentof 2 (0.295g, 0.768mmol),as describedin (b) for I, with iodine (0.591g, 2.32mmol) for 3 h lthe pH wasadjustedwith 0.54M NaHCO, (3.6 mL)] gave,after column chromatography,6 (0.214g, 52.8Vo);which crystallisedfrom CHrClr-hexane and had mp 123-124"(dec),[clo + 10. (c 0.5, CHCI3). Anal.,Calcdfor C,rH,IO'S: C, 38.67;H, 3.97.Found:C, 39.07,H,4.28. REFERENCES I I 3 { 5
R.J. Fenier. Adt- Carbohydr.Chem.,20 {o967167-t37. R.J. Ferrier, Adr. Carbohydr.Chem.Biochem.,24 (1969) l9f-266. K lgarashi,T. Honma,and T. tmagawa,l. Org.Chem.,35 (1969)610-616. J. Adamsonand D.M. Marcus,Carbohydr.Res..22(o97D257-2f/,. J. Adamson, A.B. Foster, L.D. Hall, R.N. Johnson,and R.H. Hesse.carbohydr. Ras., Li q970) 35t-359. 6 E.L. Albano, R.L. Tolman, and R.K. Robins.Carbohytlr.Res.,19(1971)63-20. 7 C.G. Butchard and P.W. Kent, Tetrahedron,7i (l9ill3457-3463. 8 R.U. Lemieuxand B. Fraser-Reid,Can.!. Chem..42egil) 535-538. 9 J. Stanekand V. Schwarz,Collect.Czech.Chem.Commun.,20(1955)42. l0 R.U. Lemieuxand S. Levine.Cun.J. Chem.,l0(l%2) 1926-1932. ll D. Horton, W. Priebe,and M. Sznaidman,Carbohydr. Res.,205(1990)7l-g6. 12 P.J.Careggand B. Samuelsson, Curbohytlr.Res.,84 (19g0)cl-c4. 13 W. Roth and W. Pigman,MethodsCurboht'dr.Chem, 2 (1963)405-406. l{ D. Miljkovii' N' Vukojevii. and D. Medakovit- carbohytlr.Res.,193 eg8r 275-279.
