#gorin - further studies on the assignment of signals in 13c of aldoses and derived meth

8/13/2019 #GORIN - Further Studies on the Assignment of Signals in 13C of Aldoses and Derived Meth

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Further Studies on the Assignment of Signals in 3C Magnetic ResonanceSpectra of Aldoses and Derived Methyl Glycosidesl

PHILIP . J. GORINAND MYTOSKM A Z U R E KPrairie Regional Laborato ry National Research Council of Can ada Saskatoon Saskatchew an S7N OW9

Received October 9,1974PHILIPA. J. GORIN nd MYTOSKMAZUREK. an. J. Chem. 53,1212(1975).The I3C signals of most of the more common sugars and their methyl glycosides have beenassigned, based on the a-carbon and a-carbon effects that occur on deuterium substitution.For pyranoses having the same hydroxyl configuration, replacement of the CH,OH substituentat C-5 with CH,, CO,H, CO,Me, or H is accompanied by displacement of the C-4, C-5, andwhen applicable C-6 signals. The magnitudes of the displacements in the glucopyranose andmannopyranose series are almost identical and were of aid in assigning signals in the 13C spec-trum of methyl (methyl a-D-mannopyranuronosid uronate.The displacements, however, differfrom corresponding ones observed in the galactopyranose series. Some assignments are madefor the I3C signals of structurally related methyl aldofuranosides.PHILIPA. J. GORIN t MYTOSKMAZUREK.an. J. Chem. 53,1212(1975).On a attribue les signaux en r.m.n. du 13C de la plupart des sucres usuels ainsi que de leursglycosides de methyle; ces attributions ont Cte faites en se basant sur les effets que produisentles carbones a et des substitutions par du deuterium. Pour des pyrannoses ayant la m meconfiguration des groupes hydroxyles, le remplacement d'un substituant C H20H en C-5 parCH3, C0 2H , C0, Me ou H s'accompagne par un dkplacement des signaux en '2-4, C-5 etlorsque c'est possible en C-6. L'amplitude de ces deplacements dans les series glucopyrannoseset mannopyrannoses sont presque identiques et a ete fort utile pour attribuer les signaux dansle spectre r.m.n. du 13C du (a-D-mannopyrannuronoside de m6thyle)uronate de mithyle. LesdCplacements different toutefois des deplacements correspondants observCs en serie galacto-pyrannose. On a fait quelques attributions pour des signaux de I3C dans des aldofurannosidesde methyle qui leur sont reli b d'une f a ~ o ntructurale. [Traduit par le journal]

In a previous study (I), the carbon-13 mag-netic resonance (I3c.m .r.) spectra of deuteratedderivatives of ap-D-glucose, ap-D-mannose, andap-D-galactose were interpreted and discussed.With the aid of two suitable deuterated deriva-tives of each aldose it was possible to make anunambiguous assignment of each signal, sincethe signals of the 13C nucleus attac hed to thedeuteron (a-carbon) disappeared and those ofthe adjacent P-carbons were displaced upfield by0.02-0.10 p.p.m. (1). Since some of the assign-ments carried out elsewhere have proved to beincorrect, the studies in this laboratory have been

alized by observing the expected a-carbon and the P-carbon deuterium isotope effects (Table 1). Although, for the most part, the sigof the a-carbon disappears, in the case 5 - 2 ~erivatives of pentoses, or the 6 - 2 Hderitives of 6-deoxyhexoses and methyl 6-deohexopyranosides, the a-13C signals appear triplets at 0.4 p.p.m. upfield (3). The P-carbeffect appeared as an upfield shift of 0.04-0.p.p.m. on mon odeuteratio n, 0.07-0.12 p.p.m.dideutera tion, and 0.17 p.p.m. for the C-3 sigof p - ~ - a r a b i n o ~ ~ r a n o s e - 4 5 - ~ ~ .he signalsa- and P-anomers of reducing sugars were dextended to most of the frequently encountered tinguished by following the mutarotation pmonosaccharides and certain derived methyl cess by 13c.m.r. spectroscopy, and those glycosides. Th e prep aratio n of the deuterated isomeric methyl glycosides, which were co

sugars was rendered easier, in most instances, by ponen ts of mixtu res, were obtained by referesynthetic routes previously devised for the un- to appropriate s tandards.deuterated counterp arts. Th e assignments mad e by these approacAs in the above study, which was relatively are summarized in Tables 2-6. The results brief, two deutera ted derivatives of each sugar tained on the methyl glycosides can be usedwere selected an d their 1 3c.m.r. spectra ration- interpreting the 1 3c.m .r. spectra of polyscharides and other sugar-containing polym'NRCC No. 14432. (4). Also, the following discussion will show t


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GORIN AND MAZUREK: N M R STUDIES OF ALDOSES 1213TABLE . Upfield displacement of 13C-C- H an d 13C- H signals of sugars* compared with those ofcorresponding I3C-C- H a n d 13C- H resonances, respectively, in p.p.m.

Sug ar Upfield displacement in p.p.m.t

aB-~-Rhamnose-6 - HMethyl a~-~-xylopyranoside-3-'HMethyl ap-~-xyIopyranoside-5-'HMethyl a(3-o-arabinopyranoside-5-'HMethyl a(3-~-arabinopyranoside-4,5-'H~Methyl up-D-galactopyranoside-4-'HMethyl a~-~-galactopyranoside-6-'H~Methyl a~-~-ribofuranoside-3-'HMethy l aD -~- r i o furanoside-5 - HMethyl ae-D-arabinofuranoside-pHMethyl a 3-~-arabinofuranoside-4,5-'H,Methyl ae-D-galactofuranoside-4-'HMethyl a~-~-galactofuranoside-6- H~Methyl 6-deoxy-a 3-~-galactopyranoside-4-'HMethyl 6-deoxy-a~-~-galactopyranoside-6-'HMethyl 6-deoxy-a~-~-glucopyranoside-6-'HMethyl 6-deoxy-ae-D-gl~copyranoside-4-~H

C,-4(0.07), Cp-4(0. 07), C.-5(0.42;20 HZ), Cp-5(0.37; 23 HZ)Cm-4(0.o), C,-4(0.12)C.-3(0. lo), C,-3(0.17)C=-3(0.08), C,-3(0.06), Cm-5(0.06)CB-5(0 06)Cm-5(0. 4), CB-5(0. 4), Cm-6(0. 0;

20 Hz), CB-6(0. 0, 20 HZ)Cm-5(0. 5), Cp-5(0. 06)Cm-3(0. 8), C,-3(0.07), Cm-5(0. 6),Cp-5(0 .06)Cm-3(0.06),Cp,-3(0.05), Ca-5(0.05),Cp-5(0. 06)C.-5(0.09), Cp-5(0.08) , Cap-6(0.41, 18 HZ)Ca-4(0.06), CB-4(0. 6)Ca-3(0.08), C,-3(0.09)Cm-3(0. 8), C,-3(0.08), Cm-5(0. 6),

C,-5(0.06)Ca-5(0.12), CD-5(0. 1)Ca-4(0.04), C,-4(0.04)Cm-3(0. 4), C,-3(0 04)C.-3(0. 04), C,-3(0 05), Cm-5(0. 8),CB-5(0. 6)Ca-5(0. 12), C,-5(0 12)C.-3(0.08), C,-3(0 07), Cm-5(006),Cp-5(0.05)C.-5(0.04), C,-5(0 05)C.-5(0.04), C,-5(0. 04)Cm-3(0. 5), Co-3(0 06), Cm-5(006),C,-5(0.05)Methyl a-L-rhamnopyranoside-4- H C.-3(0. 08), Cp-5(0. 6)Methyl a-L-rhamnopyranoside-6- H C.-5(0.05), Cap-6(0. 2; 0 68)Methyl up-D-glucopyranosiduronic cid-2- H C.-3(0.04), Cp-3(0.05)Methyl US-D-glucopyranosiduronic cid-5- H C.-4(0. 07), C,-4(0.07)Methyl (methyl a(3-D-glucopyranosid)uronate-pH C,-3(0 06), C,-3(0.06)Methyl (methyl ap-D-glucopyranosid)uronate-5-'H C.-4(0.06), Co-4(0.06)

a and i3 subscripts refer to C 1 configuration of sugar.tun les s otherwise stated, the signals of carbons attached to deuterium disappear.

signal displacements observed on changing cer-tain substituents in structurally related sugarsare consistent, so that they may be of aid ininterpreting the spectra of other sugars.

The chemical shifts of signals of 13C nuclei ofmethyl a-D-glucopyranoside may be comparedwith those of respective nuclei in methyl a-R-aldopyranosides having a C1 conformation andthe same configuration at C-2, C-3, C-4, and C-5(Table 2). On going from methyl a-D-gluco-pyranoside to methyl 6-deoxy-a-D-glucopyrano-side, methyl a-D-glucopyranosiduronic acid,

methyl (methyl a-D-glucopyranosid)uronate,andmethyl a-D-xylopyranoside, marked differencesof shift were not observed for the respective C-1,C-2, C-3, and OCH,-1 signals. Replacement ofCH OH at C-5 with CH, causes (2-4 and C-5signals to be displaced at + 6 p.p.m. (down-field) and - 4 p.p.m., respectively. These figuresare 1.9 p.p.m. and -0.8 p.p.m., respectively,when comparisons are made with the spectra of

Shifts ar e measured relative to external Me,Si, whichis always upfield from observed signals.


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TABLE . Assignment of signals in I C spectra of configurationally related sugars. The figures of the chemical shifts are in p.p.m., as are those in parentheses,which represent the difference of the shift from tha t of the correspond ing carbon in a-D-glucose and m ethyl a-D-glucopyranosidea-D-Glucose Methyl a-D-glucopyranoside

a-D-Glucose I) Meth yl a-D-glucopyranoside92.7 72.14 73.4 70.4 72.10 61.3 100.3 72.5 74.2 70.6 72.7 61.7 56.2 -

a-D-Xylose Methy l a-D-xylopyranoside93.3 72.5 73.9 70.4 62.1 100.6 72.3 74.3 70.4 62.0 56.0+0.6 ) +0.4) +0.5) 0) -10.0) +0.3) -0.2) +O.l ) -0.2) -10.7) -0.2) P

6-Deoxy-a-D-glucose Methyl 6-deoxy-a-D-glucopyranoside r93.1 72.9 73.6 76.4 68.6 18.0 73.9 76.2 68.7 17.6 56.2 V00.3 72.6+0.4 ) +0.8) +0.2) +6.0) -3.5) -43.3) 0) +O .l) -0.3) +5.6 ) -4.0) -44.1) 0)Methyl a-D-glucopyranosiduronic cid V

100.7 71.9 73.8 72.5 71.9 56.7+0.4) -0.6) -0.4) +1.9) -0.8) f0 .5)Methyl methyl a-D-g1ucopyranosid uronate

100.8 71.94 73.7 72.4 71.87 56.8 54.2+0.5) -0.6) -0.5) +1.8) -0.8) +0.6)


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TABLE. Assignment of signals in I3C spectra of configurationally related sugars. The figures of the chemical shifts are in p.p.m., as are those in parentheses,which represent the difference of the shift from that of the corresponding carbon in a-D-glucose and methyl P-D-glucopyranoside13-D-Glucose Methyl a-D-glucopyranoside

C-1 C-2 C-3 C-4 C-5 C-6 C- 1 C-2 C-3 C-4 C-5 C-6 OCHS-1 OCH3a-D-Glucose I) Methyl a-D-glucopyranoside

96.5 74.8 76.4 70.3 76.6 61.5 104.3 74.2 76.9 70.8 76.9 61.9 58.3Methyl P-D-xylopyranoside

105.1 74.0 76.9 70.4 66.3 58.3+0. 8) -0.2) 0) -0.4) -10.6) 0)

6-Deoxy-P-D-glucose Methyl 6-deoxy-P-D-glucopyranoside96.8 75.6 76.6 76.1 73.0 18.0 104.3 74.5 76.7 76.2 73.0 17.8 58.3+0.3) +0.8) +0.2 ) +5.8) -3.6) -43.5) 0) +0.3) -0.2) +5.4) -3.9) -44.1) 0)

Methyl a-D-glucopyranosiduronic cid104.3 73.8 76.5 72.3 75.6 58.50) -0.4) -0.4) +1.5) -1.3) +0.2)

Methyl methyl a-D-g1ucopyranosid uronate104.6 73.7 76.3 72.4 75.7 58.7 56.5+0.3) -0.5) -0.6) +1.6) -1.2) +0.4)


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TABLE. Assignment of signals in I Cspectra of configurationally related sug ars. The figures of the chemical shifts are in p.p.m., as a re those in parentheses,which represent the difference of the shift from tha t of the correspond ing carbon in a - and p-D-mannose and methyl a-D-mannopyranosidea- and p-D-Mannose Methyl a-D-mannopyrano side

a-D-Mannose I) Methyl a-D-mannopyranoside95.0 71.7 71.3 68.0 73.4 62.1 101.9 71.2 71.8 68.0 73.7 62.1 55.9

a-L-Rhamnose Meth yl a-L-rhamnopyranoside 395.0 71.9 71 I 73.3 69.4 18.0 101.9 71.0 71.3 73.1 69.4 17.7 55.80) +0.2) -0.2) +5.3) -4.0) -44.1) 0) -0.2) -0.5) +5.1) -4.3) -44.4) -0.1)

p-D-Mannose I) Meth yl methyl a-D-rnannopyranosid uronate*94.6 72.3 74.1 67.8 77.2 62.1 102.3 70.4 71.1 69.2 72.9 ? 56.5 54.1

+0.4) -0.8) -0.7) +1.2) -0.8) +0.6)p-L-Rhamnose94.6 72.4 73.8 72.9 73.1 18.00) +O.l) -0.3) +5.l) -4.1) -44.1)

Suggested assignments.


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TABLE. Assignment of signals n I3Cspectra of configurationally related sugars. The figures of the chemical shifts are in p.p.m., as a re those in parentheses,which represent the difference of the shift from tha t of the corrzsponding carbonin a- and p-D-galactose nd methyl a- and methyl p-D-galactopyranosidea- an d p-D-Galactose Methyl a- and methyl p-D-galactopyranoside

C- 1 C-2 C-3 C-4 C-5 C-6 C- C-2 C-3 C-4 C-5 C-6 OCHa-1 >Ia-D-Galactose I) Methyl a-D-galactopyranoside '393.6 69.8 70.56 70.63 71.7 62.5 100.5 69.4 70.6 70.4 71.8 62.3 56.3 Lk~-L- oT-)-Arabinose Methyl p-L- or D-)-arabinopyranoside C93.7 69.6 69.8 69.8 63.6 101.0 69.4 69.92 69.96 63.8 56.3 m+O.l ) -0.2) -0.8) -0.8) -8.1) +0.5) 0) -0.7) -0.4) -8.0) 0) xI:

6 Deoxy-a-D-galactose Methyl 6-deoxy-a-D-galactopyranoside93.3 69.2 70.4 73.0 67.4 16.7 100.5 69.0 70.6 72.9 67.5 16.5 56.3-0.3) -0.6) -0.2) +2.4) -4.3) -45.8) 0) -0.4) 0) +2. 5) -4.3) -45.8) 0) m

p-D-Galactose I) Methyl p-D-galactopyranoside97.7 73.3 74.2 70.1 76.3 62.3 104.9 71.8 73.9 69.8 76.2 62.1 58.3 ~-

Methyl a-L- or D-)-arabinopyranoside58.1 >105.1 71.8 7 3.4 69.4 67.3 r

+0.2) 0) -0.5) -0.4) -8.9) -0.2) '36 Deoxy-p-D-galactose Methyl 6-deoxy-p-D-galactopyranoside bV

97.3 72.8 74.0 72.5 71.9 16.7 104.8 71.5 74.1 72.4 71.9 16.5 58.3-0.4) -0.5) -0.2) +2.4) -4.4) -45.6) -0.1) -0.3) +0.2) +2.6) -4.3) -45.6) 0)


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T BLE. Assignments of signals in 13c.m.r. spectra of various methyl aldofuran osides. Chemical shifts and the figures in parentheses which represent the differ-ence of the shift of a given signal from that of the corresponding methyl galactofuranoside are in p.p.m.Methyl a-D-galac tofurano side Methyl 13-D-galactofuranoside

C- 1 C-2 C-3 C-4 C-5 C-6 OCH3-1 C- 1 C-2 C-3 C-4 C-6 C-6 0CH 3- 1Meth yl a-D-galactofuranoside Meth yl p-D-galactofuranoside

103.1 77.4 75.5 82.3 73.7 63.4 56.1 109.2 81.9 77.8 84.0 72.0 63.9 56.1Meth yl p-D-arnbinofuranoside Methy l a-D-arabinofuranoside

103.2 77.5 75.7 83.1 64.2 56.3 109.3 81.9 77.5 8,4 9 62.4+o. l) +O.l) +0.2) +0.8) -9.5) +0.2) i-0.1) 0) -0.3) +0.9) -9.6)

Methy l p-D-ribofuranoside109.0 75.3 71.9 83.9 63.9

Methyl a-D-ribojiiranoside56.3 104.2 72.1 70.8 85.5 62.2


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GORIN AND MAZUREK: N.M.R. STUDIES OF ALDOSES 2 9C0 2H or C 02 CH 3 erivatives. When the spectraof methyl a-D-glucopyranoside and methyl a Dxylopyranoside, and a-D-glucose and a-D-xyloseare compared, respectively, only the shifts of C-5signals are markedly different - 1 1 and 10p.p.m., respectively).The displacements of the C-4 and C-5 signalsrecorded for the methyl P-D-aldopyranosides aresimilar to those recorded above in the a-series,as are those which are obtained when the spectraof the p-anomers of glucose, 6-deoxyglucose, andxylose are compared (Table 3).A similar approach can be used for compari-son of the chemical shifts of the C-4 and C-5signals of a and p-D-mannose with those of aand P-L-rhamnose on one hand and for those ofmethyl a-D-mannopyranoside and methyl a Lrhamnopyranoside on the other (Table 4).Again the C-4 and C-5 signal displacements are+.5 p.p.m. and p.p.m., respectively, withoutappreciable effects on those of C-1, C-2, and C-3.Since the result of replacing a C H20H groupwith a CH, group is the same in the glucopyra-nose and mannopyranose series, little differencewould be expected between these two serieswhen a C H20H group is replaced with a C 02-CH, group. Such a relationship allows a tenta-tive assignment of signals in the 13c.m.r. spec-trum of methyl (methyl a-D-mannopyranosid)-uronate, whose deuterated derivatives would bedifficult to prepare. Using the CH 20 H toC02Me displacements in the glucopyranoseseries, which are : C-2 (-0.6), C-3 (-0.5),C-4 (+1 .8) , and C-5 (-0.8), the nearest fit ob-tained by comparison of signal displacements ofmethyl a-D-mannopyranoside and the methylester are C-2 (-0.8), C-3 (-0.7), C-4 + 1.2),and C-5 (-0.8) (see Table 4).Comparisons can be made between the shiftsof 13C signals of various sugars conformation-ally and configurationally related to galactose(Table 5). These are between: (i) a-D-galactoseand 6-deoxy-a-D-galactose, (ii) the correspond-ing P-derivatives, (iii) methyl a-D-galactopyrano-side and methyl 6-deoxy-a-D-galactopyranoside,and (io) the corresponding P-derivatives. In eachcomparison the C-5 and C-4 signals are dis-placed by 4 p.p.m. and +2.5 p.p.m., res-pectively. The downfield displacement is less than+6 p.p.m. observed in the glucopyranoseseries, which contains sugars with equatorialrather than axial OH-4 groups. However, on

going from (i) a-D-galactose to P-L-arabinose,(ii) P-D-galactose to a-L-arabinose, (iii) methyla-D-galactopyranoside to methyl P-L-arabino-pyranoside, and (iv) methyl P-D-galactopyrano-side to methyl a-L-arabinopyranoside, the C-5signals are displaced by 9 to 10 p.p.m. Thisis of the same order as is observed when the sig-nals of glucose and xylose, or their correspond-ing methyl pyranosides are compared.The signals of 13Cspectra of some of the pyra-nose sugars described above and in a previousstudy (1) have been assigned previously by othermethods. The results obtained by Perlin et al(6), who correlated chemical shifts of 13C nucleiwith electron densities based on molecular orbi-tal data, agree in most cases. Assignments of 13Csignals of ap-D-glucose, ap-D-mannose, P Dgalactose, P-D-allose, ap-D-xylose, a-arabinose,methyl P-D-galactopyranoside, methyl P-D-glu-copyranoside, and methyl ap-D-xylopyranosidewere in agreement. In the cases of a-D-galactose,methyl a-D-glucopyranoside, methyl a-D-galac-topyranoside, and methyl a-D-mannopyrano-side, some were different. Differences were alsoobserved for the C-2, C-3, and C-4 signals ofP-arabinose but since they were resolved by only0.2 p.p.m. and less, the discrepancy may be dueto the use of H 2 0 as solvent in their study andD 2 0 in ours. The latter solvent was preferredsince it appeared to suppress microbial activityand was suitable for H- ,C decoupling studies.Less agreement was attained when the presentdata were compared with the results of Dormanand Roberts (7), who used a system of empiricalconstants based on steric or proximity effects toestimate chemical shift differences. Agreementwas obtained when the assignments of 13C sig-nals of P-D-glucose, ap-D-mannose, BD-galac-tose, a-D-allose, P-D-xylose, ap-L-rhamnose,p-fucose, and methyl P-D-glucopyranoside werecompared. Their assignments of signals ofa-D-glucose, a-D-galactose, ap-arabinose, P Dallose, a-D-xylose, a-fucose, and methyl a-D-glu-copyranoside differed. The disagreement thatexists in the cases of a and 0-arabinose can be

explained partly by the differing interpretationsof the 13c.m.r. spectrum. Dorman and Roberts(7) reported a signal for each anomer that couldnot be observed by Perlin et al (6) or in thepresent study. Their discrepancy is likely due t othe slowness of recording the spectra, relative tothe speed of mutarotation.


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CAN J. CHEM VOL. 53, 1975TABLE Differences between the 13C chemical shifts of the ano mer sof D -glucose, and the respective on es of D-mannose an d D -galactose,in p.p.m.

C- C-2 C-3 C-4 C-5 C-6

The signal displacements occurring on chang-ing the nature of the substituent a t C-5 are con-fined to C-4, C-5 (and C-6 in some cases). Thus,these effects are over much shorter range thanthose observed on going from an equatorial toan axial hydroxyl group, for example, P-D-glu-cose to P-D-galactoseor P-D-glucose o p-D-man-nose. As far as these longer range effects are con-cerned, it is evident that on going from P Dglucose to p-D-mannose, with an axial OH-2group, and to P-D-galactose with an axial OH-4group, there is little correlation between signaldisplacements of carbons in the correspondingpositions relative to the axial OH group (Table7). It, therefore, does not seem profitable topursue such an approach in predicting 13Cchemical shifts of other sugars containing axialOH groups.

A certain number of methyl furanosides wereexamined and their 13c.m.r.spectra rationalized.Not surprisingly, the C-1, C-2, C-3, C-4, andOCH, signals of methyl P-D-galactofuranosidecorrespond in their shifts to those of methylP-L-arabinofuranoside and those of the corres-ponding P-hexoside to those of the a-pentoside(Table 6). Evidently the CH OH and CHOH-CH OH substituents are similar in their shield-ing or deshielding effects and d o not give rise todifferences of conformation or populations ofgiven conformations.

A few of the deuterated compounds compiledin Table 1 were prepared by routes that have notbeen described previously. For example, methyla-L-rhamnopyranoside was treated with phos-gene in pyridine to give the 2,3-cyclic carbonate,which was then oxidized with phosphorus pen-taoxide in dimethyl sulfoxide to the 2,3-cyclic

carbonate of methyl 6-deoxy-a-L-lyxohexranosid-4-ulose. Treatment with sodium bhydride provided a mixture containing mea-L-rhamnopyranoside which was identifiedits 13c.m.r. spectrum and a larger proportioanother isomer, which although it was not isted, is probably methyl 6-deoxy-ol-L-talopyside. The action of sodium borodeuteride onketone provided a mixture of the 4- H dertives of the methyl 6-deoxy-ol-L-hexopysides, which was used for assigning the 13Cnals of methyl a-L-rhamnopyranoside. The ture of aldoses prepared on hydrolysis contaap-L-rhamnose-4- H, which aided the assment of signals of ap-L-rhamnose.

D-Ribose-5- H was prepared from I ,isopropylidene ol D allofuranose by succeperiodate oxidation, sodium borodeuterideduction and hydrolysis. ~-Ribose-3- H wastained from ,2-0-isopropylidene-a-D-allofnose-3- H in a similar fashion, except sodium borohydride was used as reducing ag

ExperimentalCarbon-13 magnetic resonance spectra were obtusing a Varian XL-100-15 spectrometer with Ft ransform f rom D 2 so lu t ions (0 .85 ml) of comp(20-100 mg) contained in a coaxial glass cylinder fsnugly within a 12 mm diameter x 8 in . tube main tat 33 . Larger amo unts of solute were dissolved in

(2 ml) conta ined in the 12 mm x 8 in. tube similar tdescribed above, except that it was fitted with a Tvortex plug. T o obtain a com plete I3c.m.r. spectruspectral width was 5000 Hz, the acquisi t ion t ime an d th e pulse width 50 ps. In several experiments inecessary to improve the resolution and the spwidth was narrowed to 500 Hz, with the acquisi t ion4 s and the pulse width 117 ps. Under these condthe extent of the p-carbon deuterium isotope effect


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GORIN AND MAZUREK: N.M.R. STUDIES OF ALDOSES 1221be measured by examination of a m ixture of deuteratedand undeuterated material. Frequently signals weresuper imposed when a 5000 Hz scan was used and thosecould be resolved by preparation of two o r three spectrawith a 500 Hz sweep width and suitable offsets. Signalsof CH, gro ups were recognized as triplets in partiallydecoupled spectra. The chemical shifts are expressed as6 c in p.p.m., relative t o external M e4Si, whose shift rela-t ive to D 2 0 (lock s ignal) was ob tained in a separate

deutera ted methyl ap-D-g alactop yrano sides by refluxingin 3% methanolic hydrogen chloride fo r 3 h .S 2 H 2 nd 4,5-2H3 Derivatives of ap-D-Arabinopyra-nose, and Corresponding Deuterated Methyl

ae-D-Arabinopyranosides an d Methylap-D- rabinofi~ranosides3-~-Arabinopyranose-5-~H, as prepared from a-D-g l u c 0 s e - 6 - ~ H ~I) by the meth od used by Isbell et at. (20)for the meoaration of ~-~-arabino~vranose-5- ~Cro m~ L ~~ .experiment. a - ~ - g l u c o s e - 6 - ~ ~Some of the undeuterated chemicals used were ob- ~ : D - ~ ~ u c o s e - 5 , 6 - 2 ~ 3as prepared by acid hydrolysistained commercially and they are listed below with SUP- of ~ ~ - 0 - i ~ ~ ~ ~ ~ ~ ~ ~ i ~ ~ ~18)~ l ie rs : -D-xylose (Fisher Scientific Co., F air Law n, and converted to p-D-arabinopyranose-4 5-2H3y theN.J.), a- L-arabin ose (Nutrition al Biochemicals Cor p., same procedure,Cleveland, Ohio), a-L-rhamnose (Aldrich Chemical Co., ~ ~ t ~ ~ ~ t ~ t i ~ ~f of the arabinoses i n ~~ aveMilwaukee, Wisc.), a-L-fucose, and a- and a-anomers o f the ap-pyranosidic mixturesm et hy l D - g l u c o ~ ~ r a n o s i d en d m e th y l D - g a l a c t o ~ ~ r a n o - Treatment of the an omeric m ixture with refluxing 3%side, methy l a- and methy l 13 -~-x y lop~ra nosideSigma methano]ic hydrogen chloride for 3 h gave a mixture ofChemical Co . , S t . Lou is , Mo. ) , a-~-g lucose-2 -~HRaylo methyl ap-D-arabinopyrano~ide nd methyl ae-D-arabin-Chemicals Ltd., Edmonton, Alta.), methyl e-L-arabino- 0f~ranosic-J~.n a parallel experiment using undeuteratedpyranoside (K K Labs Inc., Plainview, N.Y.). derivatives, the glycosidic mixture g ave a 13c.m.r. spec-Other compounds were prepared according to Pro- trum with 23 of the possible 24 signals. Even when acedures described in the appe nded references. These were: spectral width of 500 H~ was used the signal at 6 c 75 .7m eth yl a - ~ - r h a m n o p y r a n ~ s i d e8), a- an d P-anomers o f f rom methyl a- and methyl p-D-arabinofuran~side ouldmethyl 6-deoxy-L-galactopyranoside 9), methyl a-D-ara- not be resolved,binofu ranosid e (lo) , methyl P-L-arabinofuranoside (1 l),methyl a - ~ - ~ ~ ~ b i ~ o p y r a n o s i d e12), methyl p-D-galacto- 6-Deox~-ap-D-gatactose-6-2H-Deoxy-ae-L-ga1ac-furano side and its minor a-anomer which are produced t o ~ e - 4 - ~ H ,erived Methyl 6-Deoxy-aP-~-galacto-s imul taneously (13), a- and o f methy l ~ - g l u c ~ - pyranosides , 6 Deoxy ap L gtucose 4 2H~nd

pyranosiduronic acid (14), methyl (methyl a-D-manno- Methy16-Dcoxy-ap-L-g1uco~~ranoside-4-2Hpyranosid )u ronate ( IS ) , and methy l 6 -deoxy-a-~-~ luco- U s in g a I l l e thod analogous to t h a t of Schmid andpyranoside (16). Kar rer (21), who reduced 1,2:3,4-di-0-isopropylidene-6-The above g lucopyranosiduron icacid derivatives were p tolylsulfonyl a D galactopyranose with lithium alumi-converted to thei r methy lesters by treatment for wi th num hydride to give 1,2:3,4-di-O-iso~rop~lidene-a-~-cold 1% methanolic HCI. fucopyranose, the 6 -2H derivative was obtained by usinglithium aluminum deuteride.Heyns et at . (22), using Pt/H2 as reagent, reducedPrepa ration of D euterate d Sug ars methyl 6 deoxy a L xylohexopyranosid 4 ulose to givea ~ - ~ - X y l o ~ ~ r a n o s e - 5 - ~ H ,~ - ~ - X y l o p y r a n o s e - 3 - ~ H , m e t h y l 6-deoxy-a-L-galactopyranosideexclusively. Usingand Derived Meth yl ap-D-Xylopyranosides Pt/D 2 we obtained the 4-'H derivative, and when sodiuma - ~ - X y l o s e - 5 - ~ Has prepared from 1,2-0-isopropy- borodeuteride in water was used .as a reagent, som elidene a D glucofuranose by successive oxida tion with methyl 6-deo~~-a-~-glucopyranoside-4-~Has formedsodium periodate, reduction with sodium borodeuteride, also, as shown by th e '3c .m.r. spectrum.and hydrolysis, as outlined by Isbell et at. (17) for the Hydrolysis of each deuterated glycoside or glycosidespreparation of a-D-xylose-5r3H. with 0 .5 M H2 S04 at 100 fo r 6 h gave the appropr i -a - ~ - X y l o s e - S - ~ Has similarly prepared from 1,2-0- ate reducing sugars. Each deuterated glycoside was equi-isopropylidene-a-D-glu~ofuranose-3-~H,btained from librated with refluxing 3% metha nolic hydrogen chlorid epartial acid hydrolysis of 1,2:5,6-di-0-isopropylidene-a- for 3 h to give the ae-glycosidic mixture.~ - g l u c o f u r a n o s e - 3 - ~ H1 8 ) . a e - ~ - R h a m n o s e - 6 - ~ H ,p - ~ - ~ h a m n o s e - 4 - ~ H ,ethylMuta rotation of each of the deuterated X Y ~ O S ~ Sn D 2 0 a-D-Rhanmopyranoside-6-~Hn d thygave ae-D-xylopyranose. a-L-Rhamnopyrano~ide-4-~HEach of th e ap-m ixtures was treated with refluxing 3% Haskin s et (23) hydrogenated methyl 2,3,4-tri-0-methano lic hydrogen ch lor ide to g ive methy l 4 - D - benzoy~-6-deoxy-6~iodo-a-~-ma~nopyran~sido givexylopyranoside. methyl 2,3,4-tri-0-benzo~l-a-D-rhamnopyranosidsing

4- 2H an d 6-2H , Derivatives of Me thy l ap-D-ga/aCto- Raney nickel in the presence of diethylamine. They Pro-furanoside and Methyl ae-D-Galactopyranoside ceeded to prepare methyl a-D-rha mno pyrano side andThe 4 -2H and 6 - 'H derivat ives o f r -D-galactose ( I ) a-D-rhamnopyranose. Th e compounds were p repared asweredissolvedin0.5~methanolichydrogenchloridewhich 6- 2H derivatives by substituting deuterium for hydrogenwas left for 15 h at room temperature (19). The produ ct in the reduction step.consisted mainly of methy l me-D-galacto fu ranoside To methy l a- L- rh am n~ p~ ra no si de6.6 g) in pyridineaccord ing to the l3c.m .r. spectru m. Th e signals of methyl (30 ml), phosgene (1.2 molar-equiv.) in toluene (20 mi)ae-D-galactofuranoside were assigned once the signals of was added with stirring. After 3 h , thesolution wasev apor-methyl ap-D-galactopyranoside were accounted for. ated to a sirup, which was partit ioned between chloroformTh e abo ve furanosidic mixtures were converted to and water. Th e chloroform layer was washed with water


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GORIN AND MAZUREK: N.M.R. STUDIES OF ALDOSES 122314. S. A. BARKER, . J BOURNEnd M STACEY. hem.Ind. London) 970 (1951).15. H. W . H. SCHMIDT.Tetrahedron Lett. 236 (1 7).16. T. E. TIMELL, ENTERMAN,. SPENCERnd E JSOLTES.Can. J Chem. 43,2296 (1965).17. H. S. ISBELL,H . FRUSH nd J D. MAYER. Res.Natl. Bur. Standards. @A, 359(1960).18. H. J KOCH nd A. S. PER LIN. arbohyd. Res. 15,403(1970).19. P. A. LEVENE, . L. RAYMONDnd R. T. DILLON..Biol. Chem. 95,699(1932).

20. H. S. ISBELL,N. B. HOLTand H. L. FRUSH. Res.Natl. Bur. Standards 57 ,95 (1956).21. H. SCHMIDnd P KARRER. elv. Chim. Acta. 32,1371 (194 9).22. K. HEYNS,A. L BARON nd H. PAULSEN. hem.Ber. 97,921 (1964).23. W. T. HASKINS, . M HANN nd C. S. HUDSON.Am. Chem. Soc. 68,6 28 (1946).24. P. M. COLLINS. etrahedron 21,1809 (1965).25. I AUGESTADnd E. BERN ER. cta. Chem. Scand. 10,911 (1956).

#gorin - further studies on the assignment of signals in 13c of aldoses and derived meth

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