Syntheses of O-β-D-mannosyl-(1 → 4)-O-α-D-mannosyl-(1 → 3)-L-rhamnose and O-(2-acetamido-2-deoxy-β-D-mannosyl)-(1 → 4)-O-α-D-galactosyl-(1 → 4)-D-galactose via in-situ-activating glycosylation using 2-O-acetyl-3,4,6-tri-O-benzyl-D-glucose

DOI: 10.1246/bcsj.76.1603

Source and publish data:

Bulletin of the Chemical Society of Japan p. 1603 - 1615 (2003)

Update date:2022-08-04

Topics:

Authors:

Koto, Shinkiti

Shinoda, Yoshika

Hirooka, Motoko

Sekino, Akiko

Ishizumi, Sachiko

Koma, Mutsuko

Matuura, Chieko

Sakata, Naoko

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Article abstract of DOI:10.1246/bcsj.76.1603

O-β-D-Mannopyranosyl-(1 → 4)-O-α-D-mannopyranosyl-(1 → 3)-L-rhamnopyranose, a trisaccharide including a repeating unit of the O-specific polysaccharide (OSP) of Bulkholderia vietnamiensis strain LMG 6988, and O-(2-acetamido-2-deoxy-β-D-mannopyranosyl)-(1 → 4)-O-α-D-galactopyranosyl-(1 → 4)-D-galactopyranose, a trisaccharide including a repeating unit of OSP of Acinetobactor baumannii serogroup O18, were synthesized by means of in-situ-activating glycosylation using 2-O-acetyl-3,4,6-tri-O-benzyl-D-glucopyranose (2ATBG) and a reagent mixture of p-nitrobenzenesulfonyl chloride, silver triflate, and 1,8-diazabicyclo[5.4.0]undec-7-ene, and related systems. New syntheses of 2ATBG, allyl 2,3,6-tri-O-benzyl-α-D-galactopyranoside, benzyl 2,3,6-tri-O-benzyl-α-D-galactopyranoside, and 2-azido-3,4,6-tri-O-benzyl-2-deoxy-D-mannopyranose are described.

Full text of DOI:10.1246/bcsj.76.1603

ꢀ 2003 The Chemical Society of Japan

Bull. Chem. Soc. Jpn., 76, 1603–1615 (2003) 1603

Syntheses of O-ꢀ-D-Mannosyl-(1 ! 4)-O-ꢁ-D-mannosyl-(1 ! 3)-L-

rhamnose and O-(2-Acetamido-2-deoxy-ꢀ-D-mannosyl)-(1 ! 4)-O-ꢁ-D-

galactosyl-(1 ! 4)-D-galactose via In-situ-activating Glycosylation Using

2-O-Acetyl-3,4,6-tri-O-benzyl-D-glucose

ꢀ

Shinkiti Koto, Yoshika Shinoda, Motoko Hirooka, Akiko Sekino, Sachiko Ishizumi,

Mutsuko Koma, Chieko Matuura, and Naoko Sakata

School of Pharmaceutical Sciences, Kitasato University, Shirokane, Minato-ku, Tokyo 108-8641

(Received December 24, 2002)

O-ꢀ-D-Mannopyranosyl-(1 ! 4)-O-ꢁ-D-mannopyranosyl-(1 ! 3)-L-rhamnopyranose, a trisaccharide including a

repeating unit of the O-speciﬁc polysaccharide (OSP) of Bulkholderia vietnamiensis strain LMG 6988, and O-(2-acet-

amido-2-deoxy-ꢀ-D-mannopyranosyl)-(1 ! 4)-O-ꢁ-D-galactopyranosyl-(1 ! 4)-D-galactopyranose, a trisaccharide in-

cluding a repeating unit of OSP of Acinetobactor baumannii serogroup O18, were synthesized by means of in-situ-ac-

tivating glycosylation using 2-O-acetyl-3,4,6-tri-O-benzyl-^D-glucopyranose (2ATBG) and a reagent mixture of p-

nitrobenzenesulfonyl chloride, silver triﬂate, and 1,8-diazabicyclo[5.4.0]undec-7-ene, and related systems. New synthe-

ses of 2ATBG, allyl 2,3,6-tri-O-benzyl-ꢁ-D-galactopyranoside, benzyl 2,3,6-tri-O-benzyl-ꢁ-D-galactopyranoside, and 2-

azido-3,4,6-tri-O-benzyl-2-deoxy-^D-mannopyranose are described.

The synthesis of the ꢀ-manno-glycoside has been one of the

most diﬃcult problems in synthetic carbohydrate chemis-

try.^1a,bMany approaches have been proposed to overcome

the diﬃculties.^1c–eAmong the modern methods reported so

far, the one involving inversive displacement of 2-triﬂyloxy

group of a compound obtainable from the protected ꢀ-gluco-

side A (Fig. 1) with OAc or N₃group to give the correspond-

ing protected ꢀ-manno-glycoside B has recently been em-

ployed in the synthesis of various ꢀ-manno-glycosides.²

The OAc or N₃group in B is ﬁnally converted into the OH

or NHAc group of the ꢀ-manno-glycoside C. Some years

ago, we have reported a simple synthesis of 2-O-acetyl-

3,4,6-tri-O-benzyl-^D-glucopyranose^3a(1) as a donor with the

participating group at the C2 position and its use for the ꢀ-glu-

cosylation with the aid of a reagent mixture of p-nitrobenzene-

sulfonyl chloride (NsCl), silver triﬂate (AgOTf), and triethyl-

amine (Et₃N) (the Nst system) as an in-situ-activating

system.^4a,5In-situ-activating glycosylation (Eq. 1) using a lac-

tol like 1 as a glycosyl donor (DOH) is convenient because

DOH þ AOH þ Reagents ! DOA

ð1Þ

no pre-activating procedure for DOH is needed in the glycosy-

lation of an acceptor (AOH). Such in-situ-activating glycosy-

lations^4,6have not been used so often in syntheses of

oligosaccharides.^5,7We then thought that 1 has a structure that

is suitable for such ꢀ-manno-glycoside synthesis, as illustrated

in Fig. 1.

ꢀ-D-Mannopyranosyl as well as 2-acetamido-2-deoxy-ꢀ-D-

mannopyranosyl structures are found in various O-speciﬁc pol-

ysaccharides (OSP) in many kinds of pathogenic micro-

organisms.⁸We planned to synthesize O-ꢀ-D-mannopyrano-

syl-(1!4)-O-ꢁ-D-mannopyranosyl-(1!3)-L-rhamnopyranose

(2) (Fig. 2), a trisaccharide including a repeating unit of the

OSP in an opportunistic pathogen, Bulkholderia vietnamiensis

strain LMG 6998,⁹and O-(2-acetamido-2-deoxy-ꢀ-D-manno-

pyranosyl)-(1 ! 4)-O-ꢁ-D-galactopyranosyl-(1 ! 4)-D-galac-

topyranose (3) (Fig. 3), a trisaccharide including a repeating

unit of the OSP of another opportunistic pathogen, Acinetobac-

tor baumannii serogroup O18.¹⁰The key step in both synthe-

ses is the in-situ-activating glycosylation using 1. The route to

the trisaccharide 2 was designed to be synthesized via a disac-

charide donor 4 (Fig. 2). This might be obtained by the con-

densation of 1 and acceptor 5, followed by the inversive dis-

placement with OAc group at the C2^bposition and

deallylation. The trisaccharide 3 was expected to be synthe-

sized via a disaccharide donor 7 (Fig. 3). This could be acces-

sible via condensation of 1 and acceptor 8, followed by the in-

versive substitution with an N₃group at the C2^bposition and

deallylation.

Fig. 1. Synthesis of ꢀ-D-mannoside and 2-acetamido-2-de-

oxy-ꢀ-D-mannoside using 2-O-acetyl-3,4,6-tri-O-benzyl-

D-glucopyranose (1).

Published on the web August 15, 2003; DOI 10.1246/bcsj.76.1603

1604 Bull. Chem. Soc. Jpn., 76, No. 8 (2003)

Synthesis of ꢀ-Mannoside and ꢀ-Mannosaminide

Fig. 2. Synthetic scheme for ꢀ-D-Manp-(1 ! 4)-ꢁ-D-

Manp-(1 ! 3)-^L-Rhap-OH (2). A code with square

shade is a donor, whereas that with round shade is an ac-

ceptor.

Fig. 3. Synthetic scheme for ꢀ-D-ManNAcp-(1 ! 4)-ꢁ-D-

Galp-(1 ! 4)-^D-Galp-OH (3). A code with square shade

is a donor, whereas that with round shade is an acceptor.

To begin with, the inversive replacements of 2-OH group of

11 as a model compound with OAc group as well as N₃group

were studied (Fig. 4). The ꢀ-condensation of cyclohexanol

with 1 having a participating OAc group at the C-2 position

was performed using a reagent mixture of Me₃SiBr, CoBr₂,

n-Bu₄NI,^11a–cinstead of n-Bu₄NBr,^4band molecular sieve

4A (MS4A). The desired ꢀ-glycoside 10 was obtained in

56% yield with a good ꢀ-selectivity (ꢀ:ꢁ = 95:5). When 1

was reacted with this reagent system in CD₂Cl₂, the ¹H

NMR spectrum of the ﬁltrate of the reaction mixture showed

two doublets, which indicated the formation of the ꢁ-iodide

D (Fig. 4) (ꢂ 7.04,^11dJ_1;2¼ 4:0 Hz) and the ꢁ-bromide E (ꢂ

6.64, J_1;2¼ 4:0 Hz); the molar ratio of D/E was ca. 1.5. Thus,

n-Bu₄NI produces the reactive glycosyl iodide D, forming 10.

A possibility that 10 might be formed via an intermediate

chloride (NsCl), silver triﬂate (AgOTf), and 1,8-diazabicy-

clo[5.4.0]undec-7-ene (DBU) (the Nsd system)^4c,5was more

eﬃcient (69% yield, after 16 h) than the Nst system^4acom-

posed of NsCl, AgOTf, and Et₃N (63% yield, after 40 h).

We consider that DBU as a strong base enhances the nucleo-

philicity of the 1-OH with the relatively higher acidity. This

will promote the formation of the respective 1-O-p-nitroben-

zenesulfonate^4dthat is believed to be the reactive intermediate

in this glycosylation reaction. Treatment of 15 with methanol-

ic NaOMe aﬀored 16. The triﬂate of 16 was reacted with n-

ꢂ

Bu₄NOAc in toluene at 50 C to give 17 in 71% yield.

ring-contracted furanoide 18 was isolated in 14%. Similar

ring-contracting reactions giving furanoides has been report-

ed.^2m–oThe furanoidal structure of 18 was conﬁrmed by mea-

suring its NMR spectra; a GHMBC spectrum showed a three-

bond-coupling between C5^band H2^b. Displacement of 2^b-OH

group with the N₃group of 16 was conducted via triﬂylati_ꢂon

and subsequent treatment with n-Bu₄NN₃in toluene at 50 C

to form 19 in 73% yield. A furanoide 20 was isolated

(22%); its GHMBC spectrum showed a coupling between

H5^band C2^b. Although the undesired furanoide formations

were not avoidable, the crucial inversions at the C2^bposition

were perfect; no trace of gluco-compounds was detected in

the reaction mixtures of either inversion reaction of 16.

As shown in Fig. 6, the synthesis of 2 was started from con-

densation of 1 and 5^7awith the aid of the Nsd system to give

the ꢀ-glucoside 21 in 80% yield. On reaction with methanolic

NaOMe, this was converted into an alcohol 22, which was then

subjected to the subsequent inversive displacement of 2^b-OH

^11d,efrom the iodide D could not be neglected. Deacetylation

of 10 with methanolic NaOMe gave 11. This was then triﬂy-

lated, followed by the substitution reaction using n-Bu₄NOAc

in toluene,^2eto give 12 in 52%. The negative speciﬁc rotation

(ꢁ11^ꢂin CHCl₃and ꢁ18^ꢂin CH₂Cl₂) and the J_C1,H1value¹²

(155.0 Hz) of 12 indicated its ꢀ-mannopyranosyl structure.

The reported speciﬁc rotation of its ꢁ-anomer is þ28:2^ꢂin

CH₂Cl₂.^2pSimilarly, triﬂation and the reaction with n-Bu₄NN₃

in toluene of 11 gave 13 (42%); the negative speciﬁc rotation

(ꢁ54^ꢂin CHCl₃) and the J_C1,H1value (156.0 Hz) of 13 were

consistent with the ꢀ-manno-form.

Next, the cellobiose derivative 16 as a more feasible model

was prepared by a condensation of 1 and 14, followed by de-

acetylation (Fig. 5). The inversive substitution of its 2^b-OH

group was then carried out. In the preparation of 15, we found

that a ternary system composed of p-nitrobenzenesulfonyl

S. Koto et al.

Bull. Chem. Soc. Jpn., 76, No. 8 (2003) 1605

Fig. 4. The inversive displacement of 2-OH group of the glucoside 11_ꢂ(Tcim = Me₃SiBr + CoBr₂+ n-Bu₄NI + MS4A, Ch =

ꢂ

cyclohexyl): a. NaOMe/MeOH/rt; b. (i) Tf₂O + Py/CH₂Cl₂, ꢁ30 C ! 20 C, (ii) n-Bu₄NOAc/PhMe, 25 C; c. (i) Tf₂O

ꢂ

+ Py/CH₂Cl₂, ꢁ30 C ! 20 C, (ii) n-Bu₄NN₃/PhMe, 25 C.

Fig. 5. The inversive displac_ꢂement of 2^b_ꢂ-OH group of the cellobioside 1_ꢂ6 (Nsd = NsCl + AgOTf + DBU): a. dil NaOMe/rt; b. (i)

ꢂ

Tf₂O + Py/CH₂Cl₂, ꢁ30 C ! 20 C, (ii) n-Bu₄NOAc/PhMe, 50 C; c. (i) Tf₂O + Py/CH₂Cl₂, ꢁ30 C ! 20 C, (ii) n-

ꢂ

Bu₄NN₃/PhMe, 50 C.

Fig. 6. Synthesis of ꢀ-D-Manp-(1 ! 4)-ꢁ-D-Manp-(1 ! 3)-L-Rhap-OH (2) (Nsd = NsCl + AgOTf + DBU): a. NaOMe/

MeOH/rt; b. (i) Tf₂O + Py/CH₂Cl₂, ꢁ30 ^ꢂC ! 20 ^ꢂC, (ii) n-Bu₄NOAc/PhMe, 50 ^ꢂC; c. PdCl₂+ NaOAc/aq AcOH

(95%), rt; d. H₂+ Pd-C (10%)/AcOH, rt.

group with OAc group. Triﬂation of 22 and the subsequent re-

action with n-Bu₄NOAc in toluene at 50 ^ꢂC aﬀorded 23 in

72% yield; a furanoid compound was isolated (12%). Mild

deallylation¹³of 23 with (Ph₃P)₃RhCl gave disaccharide donor

4, which was condensed with 6⁵with the aid of the Nsd system

to aﬀord the desired trisaccharide derivative 24 in 35% yield;

the ꢀ-linked isomer (14% yield) was isolated. The structure of

24 was conﬁrmed by observing its NMR spectra; the ꢀ-C1^c-

to-C4^blinkage and the ꢁ-C1^b-to-C3^alinkage were assigned

by the GHMBC experiments and by the NOE spectra that

show the proximity between H1^band H3^aas well as that be-

tween H1^cand H4^b. Deacetylation of 24 with methanolic

NaOMe gave 25; its catalytic debenzylation aﬀorded 2. The

NMR spectra of 2 measured in D₂O was consistent with its

structure: (1) the J_C1,H1value¹²of C1^cof 159.0 Hz indicated

ꢀ-manno-pyranosyl linkage, (2) the GHMBC experiments

showed the coupling between H1^band C3^afor the C1^b-to-

C3^alinkage and the coupling between C1^cand H4^bfor the

C1^c-to-C4^blinkage, and (3) the NOE spectra showed the prox-

imity between H1^band H3^aas well as that between H1^cand

1606 Bull. Chem. Soc. Jpn., 76, No. 8 (2003)

Synthesis of ꢀ-Mannoside and ꢀ-Mannosaminide

H4^b.

Finally, the trisacchride 3 was synthesized starting from the

new synthesis of 8^14a,bfrom 26¹⁵by means of the controlled

benzylation.¹⁶Similar to the case of methyl ꢁ-D-galactopyra-

noside,¹⁷26 was simply reacted with benzyl chloride (40 mol.

amt.) in the presence of LiOH (8 mol. amt.) at 140 ^ꢂC to aﬀord

8 in 39% (Fig. 7). This procedure was also applied to the prep-

aration of 9¹⁸from 27;¹⁹its synthesis from D-galactose was

improved. Thus, both versatile 4-OH derivatives of ^D-galac-

tose, 8 and 9, were prepared from ^D-galactose in only two steps

from ^D-galactose. Then, condensation of 1 and 8 was conduct-

ed in the presence of the Nsd system to give a ꢀ-glucoside 28

in 96% yield. Deacetylation of 28 with methanolic NaOMe at

ꢂ

35 C gave 29 in 93% yield; this was next subjected to triﬂy-

lation and the substitution reaction.^2d–kAs shown in Table 1,

the yields of 30 in the reactions using n-Bu₄NN₃in polar sol-

vents (Runs 1–5) were low (<20%). Less polar toluene as sol-

vent gave slightly better results (Run 7, 23%). Ultrasonica-

tion²⁰improved the yield of 30 (Run 9, 32%). At last, we

found that the use of CsN₃in the presence of 18-crown-6 in

toluene under ultrasonication²⁰aﬀorded 30 in 45% yield

(Run 11). Thus, the over-all yield of 30 from 8 was 40%.

The diﬃculty in the displacement reaction might occur due

to steric hindrance to the azide anion incoming upon the 2^b-

OTf group of the triﬂate derived from 29. So, we alternatively

tried the direct ꢀ-glycosylation of the donor 31^7aof which the

preparation had been improved. However, condensation of 31

and 8 with the Nst system in CH₂Cl₂aﬀorded 30 (26%), to-

gether with the ꢁ-linked isomer (53%) (ꢀ:ꢁ = 33:67). Ex-

pecting its known ꢀ-directing eﬀect,^1f–hwe used EtCN as sol-

vent; disappointingly, it made the glycosylation more ꢁ-

selective^1i,j(ꢀ:ꢁ = 27:73). The amide LiNTf₂as additive con-

verted the ꢁ-selectivity of the glycosylation using 4-O-allyl-

2,3,6-tri-O-benzyl-^D-glucopyranose and the Nst in CH₂Cl₂in-

to the ꢀ-one.^7bHowever, its use in the present instance favored

the ꢀ-anomer a little; the value of ꢁ:ꢀ remained at 40:60.

Deallylation¹³of 30 with (Ph₃P)₃RhCl aﬀorded the disac-

charide donor 7, which was ﬁnally condensed with 9 by a sys-

tem composed of NsCl, AgOTf, N,N-dimethylacetamide

(DMA), and Et₃N (Nsdt system)^4dto yield the desired trisac-

Fig. 7. Synthesis of ꢀ-D-ManNAcp-(1 ! 4)-ꢁ-D-Galp-

(1 ! 4)-^D-Galp-OH (3) (Nsd = NsCl + AgOTf +

DBU, Nsdt = NsCl + AgOTf + DMA + TEA): a. BnCl

+ LiOH/140 ^ꢂC; b. NaOMe_ꢂ/MeOH/35 ^ꢂC; c. (i) Tf₂O +

ꢂ

Py/CH₂Cl₂, ꢁ30 C ! 20 C, (ii) CsN₃+ 18-crown-6/

PhMe, ultrasonication; d. PdCl₂+ NaOAc/aq AcOH

(95%), rt; e. (i) LiAlH₄/Et₂O, ꢀ; (ii) Ac₂O/MeOH, rt;

f. H₂+ Pd-C (10%)/AcOH, rt.

Table 1. Reaction of the 2-O-Triﬂate of 29 with Azides^a)

Temperature

^ꢂC

Time

Yield of 30

Run

Azides

mol. amt.

Solvent^b)

18-Crown-6

us^c)

n-Bu₄NN₃

CsN₃

DMF

DMA

DMSO

PhMe

ꢁ

<10

CsN₃

a) Reactions were conducted in 0.03–0.09 mmol scales. b) DMA = N,N-dimethylacetamide, DMF = N,N-

dimethylformamide, DMSO = dimethyl sulfoxide. c) us = ultrasonication.

S. Koto et al.

Bull. Chem. Soc. Jpn., 76, No. 8 (2003) 1607

acetamide), and PhMe, Kanto Kagaku) were used.

charide derivative 32 in 56% yield. The structure of 32 was

conﬁrmed by observing its NMR spectra; the ꢀ-C1^c-to-C4^b

linkage and the ꢁ-C1^b-to-C4^alinkage were assigned by

GHMBC experiments and by NOE spectra that show the prox-

imity between H1^band H4^aas well as that between H1^cand

H4^b. Reduction of 32 with LiAlH₄in diethyl ether, followed

by acetylation, aﬀorded 33 in 59% yield. The last catalytic de-

benzylation of 33 gave 3. The NMR spectra of 3 measured in

D₂O was consistent with its structure: (1) the J_C1,H1value¹²of

C1^cof 158.0 Hz indicated ꢀ-manno-pyranosyl linkage, (2) the

GHMBC experiments showed the coupling between H1^band

C4^afor the C1^b-to-C4^alinkage and the coupling between

C1^c-and-H4^bfor the C1^cto C4^blinkage, and (3) the NOE

spectra showed the proximity between H1^band H4^aas well

as that between H1^cand H4^b.

In conclusion, (1) 1, easily prepared from ^D-glucose or

1,2,3,4,6-penta-O-acetyl-ꢀ-D-glucopyranose by a simple proc-

ess, is useful in the synthesis of the ꢀ-D-manno-glycosides, 2

and 3; (2) the utilities of the Nsd system as well as the Tcim

system are shown in the ꢀ-glucosylation using 1; and (3) CsN₃

in toluene with ultrasonical treatment was useful in the azide-

substitution of the 2-O-triﬂate of 29.

Chromatographically pure samples of the acetates of 8 and 9

for the determination of the NMR spectra were prepared as

described in the previous report.^7c

The donor 1 was prepared from D-glucose instead of 1,2,3,4,6-

penta-O-acetyl-ꢀ-D-glucopyranose (PAG).^3aTo a stirred mixture

of ^D-glucose (Wako, 2.0 g, 11.1 mmol) and AcBr (11 mL, 136

mmol), AcOH (5.6 mL) was added; the resulting mixture was stir-

red at 0 ^ꢂC for 20 min and then at room temperature for 90 min to

give a solution. This was evaporated and co-evaporated with

PhMe (5 mL, three times) to give a crude solid of 2,3,4,6-tetra-

O-acetyl-ꢁ-D-glucopyranosyl bromide. The solid was further

dried in vacuo over NaOH pellets overnight. The residue (4.68

g) was treated with 2,6-dimethylpyridine (8.2 mL, 70 mmol)

and MeOH (6.8 mL, 170 mmol) in MeNO₂(22 mL) at room tem-

perature overnight. The mixture was diluted with PhMe, washed

with dil NaHCO₃(5%), and evaporated to dryness to give a syrup.

To this, BnCl (60.7 mL, 0.53 mmol) and crushed KOH (30 g, 0.54

mmol) were added and the mixture was strongly stirred at 120 ^ꢂC

for 1 h. To a cooled mixture, PhMe (150 mL) and H₂O (70 mL)

were added. This organic layer was washed well with H₂O,

evaporated, and then treated with aq AcOH (80%, 40 mL) for 2

h. Work-up, chromatography using the TK system (100:1 !

10:1), and crystallization with hexane aﬀorded the previously re-

ported 1^3a(1.10 g, 20%).

Experimental⁵

The original procedure^3afor obtaining 1 from PAG was also

improved by substituting EtOH with MeOH and extraction after

orthoesteriﬁcation with evaporation. A crude bromide obtained

by a reaction of PAG (5.0 g, 13 mmol), AcBr (5.0 mL, 61 mmol),

and H₂O (1.0 mL, 56 mmol) in CHCl₃(15 mL)^3awas treated with

2,6-dimethylpyridine (4.7 mL, 41 mmol), MeOH (4.0 mL, 100

mmol) in MeNO₂(13 mL), followed by work-up, to give an yel-

low syrup. This was then treated with BnCl (70 mL, 0.61 mol)

and crushed KOH (35 g, 0.63 mol), followed by hydrolysis with

aq AcOH (80%, 40 mL). Work-up and chromatography aﬀorded

1 (5.3 g, 84%).

The solvent systems for column chromatography on silica gel

(Kanto Chemical, No. 37047; gradient elusion) and thin-layer

chromatography (TLC) (Merck, DC-Plastikfolien Kieselgel 60 F

254, Art. 5735) were CHCl₃–MeOH (CM), 1,2-dichloroethane–

AcOEt (DE), AcOEt–MeOH (EM), hexane–AcOEt (HE), and

PhMe–2-butanone (TK). Ultrasonication was carried out with a

Velvo-Clear Ultrason 95-2403 apparatus. The melting points

were determined on a Yanaco Micro Melting Point Apparatus

(Yanagimoto). The optical rotations were measured on a JASCO

DIP-180 Digital Polarimeter at room temperature. The ¹H and

¹³C NMR spectra were recorded with a Varian VXR300 spectro-

meter or a Varian XL-400 spectrometer, along with the measure-

ments of H,H-COSY, C,H-COSY, and DEPT spectra. The J_C1,H1

values¹²were determined by gated decoupling with the NOE

experiment. The assignments of the spectra of 2, 3, 24, 25, 32,

and 33 were made by auxiliary measurements of HOHAHA,

HMQC, HMBC, GHMQC, and diﬀerential NOE spectra. The

elemental analyses were carried out with a Yanaco CHN Corder

MT-5. The HRMS were recorded with a JEOL JMS-AX505HA

spectrometer and a JEOL JMS-700 spectrometer. For other items,

see the previous report.⁵

The acceptor 14²¹was rapidly prepared from commercial meth-

yl ꢀ-D-glucopyranoside monohydrate (Tokyo Kasei). A mixture

of the starting material (1.0 g, 4.7 mmol), TsOH H₂O (78.6 mg,

ꢃ

0.41 mmol), PhCH(OMe)₂(Wako, 2.0 mL, 13.3 mmol), and

DMF (6 mL) was stirred at room temperature for 16 h. To the

mixture, BnBr (3.7 mL, 31 mmol) and NaH (Wako, ca. 60% in

oil, 1.24 g, 31 mmol) were added at 0 ^ꢂC; this mixture was stirred

for 15 min and then at 20 ^ꢂC for 2 h. After addition of MeOH (3.7

mL, 93 mmol), work-up and chromatography using the TK system

(100:1 ! 20:1) aﬀorded methyl 2,3-di-O-benzyl-4,6-O-benzyli-

dene-ꢀ-D-glucopyranoside (1.42 g). Reduction of this was per-

formed in CH₂Cl₂(16 mL) containing Et₃SiH (2.7 mL, 17 mmol)

and CF₃CO₂H (1.4 mL, 19 mmol).^21aThe solution was stirred at 0

^ꢂC for 5 min and then at 20 ^ꢂC for 30 min. Evaporation and chro-

matography with the TK system (100:1 ! 10:1) yielded the pre-

viously reported 14^4d,21c(1.23 g, 56%).

The special abbreviations used here for the assigned substitu-

ents are All (allyl), Bn (benzyl), and Ch (cyclohexyl), Ns (p-nitro-

benzenesulfonyl), and Tf (triﬂuoromethanesulfonyl).

Commercial NsCl (Wako) was passed through a silica-gel col-

umn eluted with benzene, evaporated to dryness, and stored in a

dry box in a refrigerator.⁵Syrupy donors and acceptors were pu-

riﬁed by chromatography using the HE system and then stored in a

refrigerator. Commercially available AgOTf (Aldrich), Et₃N

(Tokyo Kasei), DBU (diazabicyclo[5.4.0]undec-7-ene, Tokyo

Kasei), Me₃SiBr (Tokyo Kasei), CoBr₂(Wako), molecular sieve

4A (MS4A, Hydrous), Tf₂O (Tokyo Kasei), anhydrous pyridine

(Tokyo Kasei), n-Bu₄NOAc (Fluka), n-Bu₄NI (Tokyo Kasei),

n-Bu₄NN₃(Tokyo Kasei), CsN₃(Aldrich), 18-crown-6

(1,4,7,10,13,16-hexaoxacyclooctadecane, Aldrich), and anhydrous

solvents (DMF (N,N-dimethylformamide), DMA (N,N-dimethyl-

Cyclohexyl 2-O-Acetyl-3,4,6-tri-O-benzyl-ꢀ-D-glucopyrano-

sides (10). To a stirred mixture of 1 (49 mg, 0.10 mmol), cyclo-

hexanol (12 mL, 0.11 mmol), CoBr₂(22 mg, 0.10 mmol), n-Bu₄NI

(37 mg, 0.10 mmol), powdered MS4A (49 mg), and CH₂Cl₂(0.25

mL), Me₃SiBr (13 mL, 0.10 mmol) was added at 20 ^ꢂC; the result-

ing mixture was stirred for 1.0 h. After the addition of powdered

NaHCO₃(17 mg, 0.20 mmol), the mixture was stirred for 15 min

and transferred onto the top of silica-gel column, which was de-

veloped with the TK system (100:1 ! 20:1) to give the faster-

moving ꢁ-anomer of 10 (2 mg, 3%) and 10 (32 mg, 56%) (ꢀ:ꢁ

1608 Bull. Chem. Soc. Jpn., 76, No. 8 (2003)

Synthesis of ꢀ-Mannoside and ꢀ-Mannosaminide

= 95:5).

Hz, J_6a,6b¼ 10:0 Hz, H6a), 3.78 (dd, J_5;6b¼ 2:0 Hz,

J_6a,6b¼ 10:0 Hz, H6b), 4.38 (d, J_1;2¼ 7:5 Hz, H1); ¹³C NMR

(CDCl₃, 75 MHz) ꢂ 24.0, 24.1, 25.5, 32.0, 33.6 (Ch), 69.2 (C6),

74.8 (C2), 75.2 (C5), 77.6 (Ch), 77.7 (C4), 84.6 (C3), 101.1

(C1). Found: C, 74.35; H, 7.67%. Calcd for C₃₃H₄₀O₆: C,

74.41; H, 7.57%.

10: ½ꢁꢄ_Dꢁ12^ꢂ(c 0.4, CHCl₃); ¹H NMR (CDCl₃, 300 MHz) ꢂ

1.98 (s, Ac), 3.50 (ddd, J_4;5¼ 9:5 Hz, J_5;6a¼ 5:0 Hz, J_5;6b¼ 2:0

Hz, H5), 3.63 (m, Ch), 3.66 (t, J_3;4¼ J_4;5¼ 9:5 Hz, H4), 3.68 (dd,

J_2;3¼ J_3;4¼ 9:5 Hz, H3), 3.69 (dd, J_5;6a¼ 5:0 Hz, J_6a,6b¼ 10:5

Hz, H6a), 3.77 (dd, J_5;6b¼ 2:0 Hz, J_6a,6b¼ 10:5 Hz, H6b), 4.45

(d, J_1;2¼ 8:0 Hz, H1), 4.99 (dd, J_1;2¼ 8:0 Hz, J_2;3¼ 9:5 Hz,

H2); ¹³C NMR (CDCl₃, 75 MHz) ꢂ 20.9 (Ac), 23.6, 23.7, 25.6,

31.7, 33.4 (Ch), 69.0 (C6), 73.5 (C2), 75.2 (C4), 77.4 (Ch), 78.2

(C4), 83.1 (C3), 99.7 (C1), 169.3 (Ac). HRMS (FAB) Found:

m=z 597.2846. Calcd for C₃₅H₄₂NaO₇[M + Na]^þ: 597.2828.

Cyclohexyl 2-O-Acetyl-3,4,6-tri-O-benzyl-ꢀ-D-mannopyra-

noside (12). To a stirred mixture of 11 (25 mg, 0.047 mmol),

pyridine (51 mL, 0.63 mmol), and CH₂Cl₂(0.51 mL), Tf₂O (80

mL, 0.49 mmol) was added at below ꢁ30 ^ꢂC bath temperature.

The resulting heterogeneous mixture was stirred at below ꢁ25

^ꢂC for 5 min and then at 0 ^ꢂC for 5 min. The mixture was further

stirred at 10 ^ꢂC for 5 min and then at 20 ^ꢂC for 20 min. After H₂O

(15 mL, 0.83 mmol) was added to the mixture at 0 ^ꢂC with stirring,

the mixture was diluted with hexane and chromatographed with

the TK system (100:1 ! 20:1) to yield a homogeneous syrup.

To this, n-Bu₄NOAc (129 mg, 0.43 mmol) and anhydrous PhMe

The ꢁ-anomer: ½ꢁꢄ_D+76^ꢂ(c 0.5, CHCl₃); ¹H NMR (CDCl₃,

300 MHz) ꢂ 2.04 (s, Ac), 3.57 (m, Ch), 3.68 (dd, J_5;6a¼ 2:0 Hz,

J_6a,6b¼ 10:5 Hz, H6a), 3.72 (dd, J_3;4¼ 9:0 Hz, J_4;5¼ 10:0 Hz,

H4), 3.79 (dd, J_5;6b¼ 3:5 Hz, J_6a,6b¼ 10:5 Hz, H6b), 3.95 (ddd,

J_4;5¼ 10:0 Hz, J_5;6a¼ 2:0 Hz, J_5;6b¼ 3:5 Hz, H5), 4.05 (dd,

J_2;3¼ 10:0 Hz, J_3;4¼ 9:0 Hz, H3), 4.82 (dd, J_1;2¼ 4:0 Hz, J_2;3

10:0 Hz, H2), 5.21 (d, J_1;2¼ 4:0 Hz, H1); ¹³C NMR (CDCl₃, 75

MHz) ꢂ 20.1 (Ac), 23.6, 24.0, 25.6, 31.4, 33.2 (Ch), 68.5 (C6),

70.3 (C5), 74.0 (C2), 75.7 (Ch), 77.9 (C4), 80.4 (C3), 94.2 (C1),

170.3 (Ac); HRMS (FAB) Found: m=z 597.2870. Calcd for

C₃₅H₄₂NaO₇[M + Na]^þ: 597.2828.

(0.22 mL) were added. After stirring at 25 C for 16 h, the mix-

ture was diluted with hexane, and chromatographed with the TK

ꢂ

system (100:1 ! 20:1) to give 12 (14 mg, 52%); ½ꢁꢄ_Dꢁ11^ꢂ

(c 1.1, CHCl₃), ½ꢁꢄ_Dꢁ11^ꢂ(c 0.9, CH₂Cl₂) (Ref. 2p, ꢁ-anomer,

½ꢁꢄ_D+28.2^ꢂ(c 1.77, CH₂Cl₂)); H NMR (CDCl₃, 300 MHz) ꢂ

2.20 (s, Ac), 3.48 (ddd, J_4;5¼ 9:0 Hz, J_5;6a¼ 6:0 Hz, J_5;6b¼ 2:0

Hz, H5), 3.64 (dd, J_2;3¼ 3:0 Hz, J_3;4¼ 9:0 Hz, H3), 3.68 (t,

J_3;4¼ J_4;5¼ 9:0 Hz, H4), 3.72 (dd, J_5;6a¼ 6:0 Hz, J_6a,6b¼ 10:5

Hz, H6a), 3.80 (dd, J_5;6b¼ 2:0 Hz, J_6a,6b¼ 10:5 Hz, H6b), 4.63

(d, J_1;2¼ 1:0 Hz, H1), 5.58 (dd, J_1;2¼ 1:0 Hz, J_2;3¼ 3:0 Hz,

H2); ¹³C NMR (CDCl₃, 75 MHz) ꢂ 21.2 (Ac), 23.8, 23.9, 25.6,

31.6, 33.2 (Ch), 68.8 (C2), 69.5 (C6), 74.5 (C4), 75.5 (C5), 76.9

(Ch), 80.6 (C3), 96.7 (C1, J_C1,H1¼ 155:0 Hz), 170.8 (Ac). HRMS

(FAB) Found: m=z 597.2864. Calcd for C₃₅H₄₂NaO₇[M + Na]^þ:

597.2828.

When n-Bu₄NBr^4b(32 mL, 0.10 mmol) was used instead of n-

Bu₄NI and the reaction was conducted for 3 h at room tempera-

ture, the ꢁ-anomer (9 mg, 16%) and 10 (28 mg, 49%) were ob-

tained (ꢀ:ꢁ = 75:25).

A glycosylation using Me₃SiBr (13 mL, 0.10 mmol), CoI₂(31

mg, 0.10 mmol), and MS4A (49 mg) in CH₂Cl₂(0.25 ml) gave

the ꢁ-anomer (4 mg, 7%) and 10 (36 mg, 63%) (ꢀ:ꢁ = 90:10) af-

ter 1 h.

A condensation in the presence of Me₃SiI (14.2 mL, 0.10

mmol), CoBr₂(22 mg, 0.10 mmol), and MS4A (49 mg) in CH₂Cl₂

(0.25 mL) gave the ꢁ-anomer (7 mg, 12%) and 10 (32 mg, 56%)

(ꢀ:ꢁ = 82:18) after 1 h, whereas that using Me₃SiBr (13 mL, 0.10

mmol), CoBr₂(22 mg, 0.10 mmol), and MS4A (49 mg) in CH₂Cl₂

(0.25 mL) gave the ꢁ-anomer (4.5 mg, 8%) and 10 (18 mg, 31%)

(ꢀ:ꢁ = 79:21), after 2 h.

NMR Study Detecting 2-O-Acetyl-3,4,6-tri-O-benzyl-ꢁ-D-

glucopyranosyl Iodide D and Bromide E. To a stirred mixture

of 1 (25.0 mg, 0.051 mmol), CoBr₂(11.1 mg, 0.051 mmol), n-

Bu₄NI (18.8 mg, 0.051 mmol), MS4A (49 mg), and CD₂Cl₂con-

taining TMS (1%) (Aldrich, 1.0 mL), Me₃SiBr (6.6 mL, 0.051

mmol) was added at room temperature. After 1 h, the mixture

Cyclohexyl 2-Azido-3,4,6-tri-O-benzyl-2-deoxy-ꢀ-D-manno-

pyranoside (13). Triﬂylation of 11 (27.6 mg, 0.052 mmol) with

Tf₂O (87.2 mL, 0.53 mmol), pyridine (55.5 mL, 0.69 mmol), and

CH₂Cl₂(0.55 mL) and following chromatography as described

for 12 yielded a homogeneous syrup. Subsequent reaction with

n-Bu₄NN₃(33.8 mg, 0.12 mmol) in anhydrous PhMe (0.18 mL)

ꢂ

for 16 h at 25 C, followed by chromatography as described for

12, gave 13 (12 mg, 42%); ½ꢁꢄ_Dꢁ54^ꢂ(c 1.3, CHCl₃); ¹H

NMR (CDCl₃, 300 MHz) ꢂ 3.40 (ddd, J_4;5¼ 9:0 Hz, J_5;6a¼ 5:5

Hz, J_5;6b¼ 2:0 Hz, H5), 3.63 (dd, J_2;3¼ 3:5 Hz, J_3;4¼ 9:0 Hz,

H3), 3.69 (dd, J_5;6a¼ 5:5 Hz, J_6a,6b¼ 11:0 Hz, H6a), 3.72 (t,

J_3;4¼ J_4;5¼ 9:0 Hz, H4), 3.76 (dd, J_5;6b¼ 2:0 Hz, J_6a,6b¼ 11:0

Hz, H6b), 3.92 (dd, J_1;2¼ 1:0 Hz, J_2;3¼ 3:5 Hz, H2), 4.60 (d,

J_1;2¼ 1:0 Hz, H1); ¹³C NMR (CDCl₃, 75 MHz) ꢂ 23.76, 23.84,

25.6, 31.6, 33.4 (Ch), 62.5 (C2), 69.4 (C6), 74.7 (C4), 75.8

(C5), 76.9 (Ch), 81.2 (C3), 97.7 (C1, J_C1,H1¼ 156:0 Hz). Found:

C, 70.91; H, 7.09; N, 7.35%. Calcd for C₃₃H₃₉N₃O₅: C, 71.07; H,

7.05; N, 7.53%.

was ﬁltered through a pad of cotton. The H NMR spectrum of

the ﬁltrate determined at 300 MHz clearly showed two doublets

at ꢂ 6.64 (J_1;2¼ 4:0 Hz, H1 of E) and at ꢂ 7.04 (J_1;2¼ 4:0 Hz,

H1 of D) in the region of ꢂ 5.4–7.2.

Separately, 1 (25.0 mg, 0.051 mmol) was reacted with Me₃SiBr

(6.6 mL, 0.051 mmol), CoBr₂(11.1 mg, 0.051 mmol), n-Bu₄NBr

(16.4 mg, 0.051 mmol), and MS4A (49 mg) in CD₂Cl₂containing

TMS (1%) (Aldrich, 1.0 mL). The H NMR spectrum of the ﬁl-

trate showed one doublet of E at ꢂ 6.64 (J_1;2¼ 4:0 Hz, H1 of E) in

the above-described region.

Methyl O-(2-O-Acetyl-3,4,6-tri-O-benzyl-ꢀ-D-glucopyrano-

syl)-(1 ! 4)-2,3,6-tri-O-benzyl-ꢀ-D-glucopyranoside (15). To

a stirred mixture of 1 (41 mg, 0.083 mmol), 14 (30 mg, 0.065

mmol), NsCl (36 mg, 0.16 mmol), AgOTf (42 mg, 0.016 mmol),

and CH₂Cl₂(0.30 mL), DBU (24 mL, 0.16 mmol) was added at

Cyclohexyl 3,4,6-Tri-O-benzyl-ꢀ-D-glucopyranoside (11).

A mixture of 10 (218 mg, 0.38 mmol), MeOH (17 mL) and meth-

anolic NaOMe (7%, 0.3 mL) was kept standing overnight. Neu-

tralization with AcOH, evaporation and chromatography with the

ꢂ

ꢁ60 C (bath temperature); this mixture was stirred under unhy-

drous conditions, while the reaction temperature was gradually

raised to 0 ^ꢂC (ca. 0.3 ^ꢂC/min). The mixture was then stirred

at this temperature for 16 h. After the addition of NaHCO₃(45

mg, 0.53 mmol) and PhMe (2 mL), the mixture was chromato-

graphed with the TK system (100:1 ! 10:1) to aﬀord 15 (42

TK system (100:1 ! 20:1) aﬀorded 11²²(188 mg, 93%); ½ꢁꢄ_D

ꢁ11^ꢂ(c 1.1, CHCl₃); ¹H NMR (CDCl₃, 300 MHz) ꢂ 2.40 (s, OH),

3.51 (ddd, J_4;5¼ 9:0 Hz, J_5;6a¼ 4:5 Hz, J_5;6b¼ 2:0 Hz, H5), 3.60

(dd, J_1;2¼ 7:5 Hz, J_2;3¼ 9:0 Hz, H2), 3.61 (t, J_2;3¼ J_3;4¼ 9:0

Hz, H3), 3.69 (t, J_3;4¼ J_4;5¼ 9:0 Hz, H4), 3.69 (dd, J_5;6a¼ 4:5

mg, 69%); ½ꢁꢄ_D+18^ꢂ(c 0.2, CHCl₃) (Ref. 3a, ½ꢁꢄ_D+21^ꢂ(c

S. Koto et al.

Bull. Chem. Soc. Jpn., 76, No. 8 (2003) 1609

1.8, CHCl₃)); ¹H NMR (CDCl₃, 300 MHz) ꢂ 1.88 (s, Ac), 3.29

(ddd, J_4;5¼ 9:5 Hz, J_5;6a¼ 2:0 Hz, J_5;6b¼ 4:0 Hz, H5^b), 3.37

(m, H5^a), 3.37 (dd, J_1;2¼ 8:0 H, J_2;3¼ 9:0 Hz, H2^a), 3.50 (t,

J_2;3¼ J_3;4¼ 9:0 Hz, H3^b), 3.51 (dd, J_5;6a¼ 4:0 Hz,

J_6a,6b¼ 11:0 Hz, H6a^b), 3.55 (s, Me), 3.60 (t, J_2;3¼ J_3;4¼ 9:0

Hz, H3^a), 3.62 (dd, J_5;6b¼ 2:0 Hz, J_6a,6b¼ 11:0 Hz, H6b^b), 3.69

(dd, J_3;4¼ 9:0 Hz, J_4;5¼ 9:5 Hz, H4^b), 3.90 (dd, J_3;4¼ 9:0 Hz,

J_4;5¼ 10:0, H4^a), 4.26 (d, J_1;2¼ 8:0 Hz, H1^a), 4.59 (d,

J_1;2¼ 8:0 Hz, H1^b), 4.96 (dd, J_1;2¼ 8:0 Hz, J_2;3¼ 9:0 Hz,

H2^b); ¹³C NMR (CDCl₃, 75 MHz) ꢂ 20.9 (Ac), 56.9 (Me), 68.2

(C6^a), 68.7 (C6^b), 73.8 (C2^b), 74.9 (C5^a), 75.2 (C5^b), 76.9

(C4^a), 78.1 (C4^b), 81.9 (C2^a), 82.7 (C3^a), 83.1 (C3^b), 100.3

(C1^b), 104.6 (C1^b), 169.3 (Ac); HRMS (FAB) Found: m=z

961.4146. Calcd for C₅₇H₆₂NaO₁₂[M + Na]^þ: 961.4139.

tyl]]-2,3,6-tri-O-benzyl-ꢀ-D-glucopyranoside (18) (3.3 mg, 14%);

½ꢁꢄ_D+22^ꢂ(c 0.4, CHCl₃); H NMR (CDCl₃, 400 MHz) ꢂ 1.65

(s, Ac), 3.33 (ddd, J_4;5¼ 10:0 Hz, J_5;6a¼ 5:0 Hz, J_5;6b¼ 2:0 Hz,

H5^a), 3.37 (dd, J_1;2¼ 8:0 Hz, J_2;3¼ 9:0 Hz, H2^a), 3.47 (t, J_2;3

J_3;4¼ 9:0 Hz, H3^a), 3.53 (s, Me), 3.56 (dd, J_4;5a¼ 5:0 Hz, J_5a,5b

10:5 Hz, H5a^b), 3.59 (dd, J_4;5b¼ 9:0 Hz, J_5a,5b¼ 10:5 Hz, H5b^b),

3.73 (dd, J_5;6a¼ 5:0 Hz, J_6a,6b¼ 11:0 Hz, H6a^a), 3.78 (dd, J_5;6b

2:0 Hz, J_6a,6b¼ 11:0 Hz, H6b^a), 3.89 (dd, J_3;4¼ 9:0 Hz,

J_4;5¼ 10:0 Hz, H4^a), 4.05 (dd, J_1;2¼ 4:5 Hz, J_2;3¼ 3:5 Hz,

H2^b), 4.08 (dd, J_3;4¼ 3:5 Hz, J_4;5¼ 5:5 Hz, H4^b), 4.20 (ꢅt,

J_4;5¼ 5:5 Hz, J_5;6a¼ J_5;6b¼ 5:0 Hz, H5^b), 4.22 (d, J_1;2¼ 8:0

Hz, H1^a), 4.32 (t, J_2;3¼ J_3;4¼ 3:5 Hz, H3^b), 6.16 (d, J_1;2¼ 4:5

Hz, H1^b); 3.53 (s, Me); ¹³C NMR (CDCl₃, 100 MHz) ꢂ 20.9

(Ac), 56.9 (Me), 68.5 (C6^a), 69.9 (C6^b), 74.9 (C5^a), 77.6 (C4^a),

81.9 (C5^b), 82.0 (C2^a), 82.6 (C3^a), 83.2 (C2^b), 84.3 (C3^b), 84.8

(C4^b), 95.3 (C1^b), 104.5 (C1^a), 170.5 (Ac). HRMS (FAB) Found:

m=z 961.4186. Calcd for C₅₇H₆₂NaO₁₂[M + Na]^þ: 961.4139.

Methyl O-(2-Azido-3,4,6-tri-O-benzyl-2-deoxy-ꢀ-D-manno-

pyranosyl)-(1 ! 4)-2,3,6-tri-O-benzyl-ꢀ-D-glucopyranoside

(19). Triﬂylation of 16 (20 mg, 0.022 mmol) with Tf₂O (77 mL,

0.47 mmol) and pyridine (49 mL, 0.60 mmol) in CH₂Cl₂(0.41

mL) as described for 12 gave a syrup (21.7 mg). To this, n-

Bu₄NN₃(63 mg, 0.22 mmol) and anhydrous PhMe (0.15 mL)

Methyl

O-(3,4,6-Tri-O-benzyl-ꢀ-D-glucopyranosyl)-

(1 ! 4)-2,3,6-tri-O-benzyl-ꢀ-D-glucopyranoside (16). A mix-

ture of 15 (174 mg, 0.19 mmol), MeOH (13 mL), and methanolic

NaOMe (7%, 0.3 mL) was kept stirring at room temperature

overnight. After the neutralization with AcOH, evaporation,

and chromatography with the TK system (100:1 ! 10:1) aﬀorded

16 (161 mg, 97%); ½ꢁꢄ_D²⁴+20^ꢂ(c 1.2, CHCl₃); ¹H NMR (CDCl₃,

300 MHz) ꢂ 1.60 (s, OH), 3.21 (ddd, J_4;5¼ 10:0 Hz, J_5;6a¼ 3:5

Hz, J_5;6b¼ 2:0 Hz, H5^b), 3.42 (dd, J_1;2¼ 8:0 Hz, J_2;3¼ 9:0 Hz,

H2^a), 3.43 (dd, J_5;6a¼ 2:0 Hz, J_6a,6b¼ 11:0 Hz, H6a^b), 3.48

(dd, J_1;2¼ 8:0 Hz, J_2;3¼ 9:0 Hz, H2^b), 3.48 (t, J_2;3¼ J_3;4¼ 9:0

Hz, H3^b), 3.49 (dd, J_5;6a¼ 3:5 Hz, J_6a,6b¼ 11:0 Hz, H6b^b),

3.49 (ddd, J_4;5¼ 9:0 Hz, J_5;6a¼ 2:0 Hz, J_5;6b¼ 3:5 Hz, H5^a),

3.54 (ꢅt, J_3;4¼ 9:0 Hz, J_4;5¼ 10:0, H4^b), 3.55 (dd, J_5;6b¼ 2:0

Hz, J_6b,6b¼ 10:0 Hz, H6b^b), 3.57 (s, Me), 3.68 (t,

J_2;3¼ J_3;4¼ 9:0 Hz, H3^a), 3.80 (dd, J_5;6a¼ 2:0 Hz,

J_6a,6b¼ 11:0 Hz, H6a^a), 3.98 (dd, J_5;6b¼ 3:5 Hz, J_5a,6b¼ 11:0

Hz, H6b^a), 4.03 (t, J_3;4¼ J_4;5¼ 9:0 Hz, H4^a), 4.31 (d,

J_1;2¼ 8:0 Hz, H1^a), 4.61 (d, J_1;2¼ 8:0 Hz, H1^b); ¹³C NMR

(CDCl₃, 75 MHz) ꢂ 57.8 (Me), 68.6 (C6^b), 68.9 (C6^a), 74.4

(C2^b), 75.2 (C5^b), 75.8 (C5^a), 77.0 (C4^a), 77.4 (C4^b), 82.3

(C2^a), 83.5 (C3^a), 84.5 (C3^b), 103.3 (C1^b), 104.8 (C1^b). Found:

C, 73.55; H, 6.87%. Calcd for C₅₅H₆₀O₁₁: C, 73.64; H, 6.74%.

Methyl O-(2-O-Acetyl-3,4,6-tri-O-benzyl-ꢀ-D-mannopyra-

nosyl)-(1 ! 4)-2,3,6-tri-O-benzyl-ꢀ-D-glucopyranoside (17).

Triﬂylation of 16 (23 mg, 0.026 mmol) with Tf₂O (82 mL, 0.50

mmol) and pyridine (55 mL, 0.68 mmol) in CH₂Cl₂(0.46 mL)

in a manner similar to the transformation of 11 into 12 gave a syr-

up (24 mg). To this, n-Bu₄NOAc (62 mg, 0.21 mmol) and anhy-

drous PhMe (0.17 mL) were added; the resulting mixture was stir-

ꢂ

were added; the resulting mixture was stirred at 50 C for 16 h,

followed by chromatography using the TK system (100:1 !

10:1) as described for 12, to give 19 (15 mg, 73%); ½ꢁꢄ_Dꢁ1^ꢂ

(c 0.3, CHCl₃); ¹H NMR (CDCl₃, 300 MHz) ꢂ 3.18 (ddd,

J_4;5¼ 10:0 Hz, J_5;6a¼ 4:0 Hz, J_5;6b¼ 2:5 Hz, H5^b), 3.41 (dd,

J_1;2¼ 7:5 Hz, J_2;3¼ 9:0 Hz, H2^a), 3.42 (dd, J_2;3¼ 3:0 Hz, J_3;4

9:0 Hz, H3^b), 3.50 (ddd, J_4;5¼ 9:0 Hz, J_5;6a¼ 2:5 Hz, J_5;6b¼ 4:0

Hz, H5^a), 3.52 (dd, J_5;6a¼ 4:0 Hz, J_6a,6b¼ 11:0 Hz, H6a^b), 3.57

(s, OMe), 3.61 (dd, J_5;6b¼ 2:0 Hz, J_6a,6b¼ 11:0 Hz, H6b^b),

3.70 (t, J_2;3¼ J_3;4¼ 9:0 Hz, H3^a), 3.76 (dd, J_3:4¼ 9:0 Hz, J_4;5

10:0 Hz, H4^b), 3.76 (dd, J_5;6a¼ 2:5 Hz, J_6a,6b¼ 11:0 Hz, H6a^a),

3.85 (dd, J_5;6b¼ 4:0 Hz, J_6a,6b¼ 11:0 Hz, H6b^a), 3.87 (dd, J_1;2

1:0 Hz, J_2;3¼ 3:0 Hz, H2^b), 3.95 (t, J_3;4¼ J_4;5¼ 9:0 Hz, H4^a),

4.31 (d, J_1;2¼ 7:5 Hz, H1^a), 4.66 (d, J_1;2¼ 1:0 Hz, H1^a); ¹³C

NMR (CDCl₃, 75 MHz) ꢂ 57.1 (Me), 61.8 (C2^b), 68.78 (C6^a),

68.83 (C6^b), 74.1 (2C, C4^aand C5^a), 75.8 (C5^b), 76.8 (C4^a),

81.2 (C3^b), 82.0 (C2^a), 83.0 (C3^a), 99.7 (C1^b, J_C1,H1¼ 158:0

Hz), 104.7 (C1^b, J_C1,H1¼ 158:9 Hz). HRMS (FAB) Found:

m=z 944.4098. Calcd for C₅₅H₅₉N₃NaO₁₀[M + Na]^þ: 944.4098.

Before the elution of 19, there appeared a single isomer of

methyl 4-O-[(1R=S)-[2,5-anhydro-1-azido-3,4,6-tri-O-benzyl-^D-

mannityl]]-2,3,6-tri-O-benzyl-ꢀ-D-glucopyranoside (20) (4.6 mg,

ꢂ

red at 50 C for 16 h, followed by chromatography using the TK

system (100:1 ! 10:1), to give 17 (17 mg, 71%); ½ꢁꢄ_Dꢁ5^ꢂ(c

22%); ½ꢁꢄ_D+19^ꢂ(c 0.3, CHCl₃); ¹H NMR (CDCl₃, 400

0.6, CHCl₃); ¹H NMR (CDCl₃, 300 MHz) ꢂ 2.10 (s, Ac), 3.23

(ddd, J_4;5¼ 9:5 Hz, J_5;6a¼ 2:0 Hz, J_5;6b¼ 4:0 Hz, H5^b), 3.39

(dd, J_2;3¼ 3:0 Hz, J_3;4¼ 9:0 Hz, H3^b), 3.39 (dd, J_1;2¼ 8:0 Hz,

J_2;3¼ 9:0 Hz, H2^a), 3.45 (ddd, J_4;5¼ 10:0 Hz, J_5;6a¼ 3:0 Hz,

J_5;6b¼ 6:0 Hz, H5^a), 3.56 (s, Me), 3.62 (t, J_2;3¼ J_3;4¼ 9:0 Hz,

MHz) ꢂ 3.24 (ddd, J_4;5¼ 9:5 Hz, J_5;6a¼ 2:0 Hz, J_5;6b¼ 3:5 Hz,

H5^a), 3.43 (dd, J_1;2¼ 8:0 Hz, J_2;3¼ 9:0 Hz, H2^a), 3.54 (s, Me),

3.54 (t, J_2;3¼ J_3;4¼ 9:0 Hz, H3^a), 3.59 (dd, J_5;6a¼ 5:5 Hz,

J_6a,6b¼ 11:5 Hz, H6a^b), 3.60 (dd, J_5;6b¼ 5:5 Hz, J_6a,6b¼ 11:5

Hz, H6b^b), 3.64 (dd, J_5;6a¼ 2:0 Hz, J_6a,6b¼ 11:0 Hz, H6a^a),

H3^a), 3.75 (dd, J_3;4¼ 9:0 Hz, J_4;5¼ 9:5 Hz, H4^b), 3.99 (dd, J_3;4

3.71 (dd, J_5;6b¼ 3:5 Hz, J_6a,6b¼ 11:0 Hz, H6b^a), 3.79 (dd, J_3;4

9:0 Hz, J_4;5¼ 10:0 Hz, H4^a), 4.29 (d, J_1;2¼ 8:0 Hz, H1^a), 4.69 (s,

H1^b), 5.45 (d, J_1;2¼ 0 Hz, J_2;3¼ 3:0 Hz, H2^b); ¹³C NMR

(CDCl₃, 75 MHz) ꢂ 21.1 (Ac), 57.1 (Me), 68.5 (C2^b), 68.8

(C6^a), 68.9 (C6^b), 74.1 (2C, C5^aand C4^b), 75.6 (C5^b), 77.3

(C4^a), 80.5 (C3^b), 82.0 (C2^a), 83.1 (C3^a), 99.2 (C1^b,

J_C1,H1¼ 158:7 Hz), 104.7 (C1^a, J_C1,H1¼ 154:5 Hz), 170.6 (Ac).

Found: C, 72.59; H, 6.62%. Calcd for C₅₇H₆₂O₁₂: C, 72.90; H,

6.65%.

9:0 Hz, J_4;5¼ 9:5 Hz, H4^a), 4.07 (dd, J_1;2¼ 5:5 Hz, J_2;3¼ 3:0

Hz, H2^b), 4.09 (dd, J_3;4¼ 3:0 Hz, J_4;5¼ 4:5 Hz, H4^b), 4.15 (t,

J_2;3¼ J_3;4¼ 3:0 Hz, H3^b), 4.22 (dt, J_4;5¼ 4:5 Hz, J_5;6a¼ J_5;6b

5:5 Hz, H5^b), 4.24 (d, J_1;2¼ 8:0 Hz, H1^a), 4.93 (d, J_1;2¼ 5:5 Hz,

H1^b); ¹³C NMR (CDCl₃, 100 MHz) ꢂ 56.9 (Me), 68.1 (C6^a), 69.9

(C6^b), 74.7 (C5^a), 76.0 (C4^a), 82.1 (C2^a), 82.4 (2C, C3^aand C5^b),

84.3 (C3^b), 84.6 (C4^b), 84.8 (C2^b), 91.0 (C1^b), 104.6 (C1^a);

HRMS (FAB) Found: m=z 944.4096. Calcd for C₅₅H₅₉N₃NaO₁₀

[M + Na]^þ: 944.4098.

Before elution of 17, there appeared a single isomer of methyl

4-O-[(1R=S)-[1-acetoxy-2,5-anhydro-3,4,6-tri-O-benzyl-^D-manni-

Allyl

O-(2-O-Acetyl-3,4,6-tri-O-benzyl-ꢀ-D-glucopyrano-

1610 Bull. Chem. Soc. Jpn., 76, No. 8 (2003)

Synthesis of ꢀ-Mannoside and ꢀ-Mannosaminide

syl)-(1 ! 4)-2,3,6-tri-O-benzyl-ꢁ-D-mannopyranoside (21).

Condensation of 1 (231.7 mg, 0.47 mmol) and 5 (177.5 mg,

0.36 mmol) in the presence of NsCl (200.6 mg, 0.91 mmol),

AgOTf (232.7 mg, 0.91 mmol), and DBU (134.9 mL, 0.91 mmol)

in CH₂Cl₂(1.8 mL), followed by chromatography with the TK

H1^a), 5.45 (dd, J_1;2¼ 1:0 Hz, J_2;3¼ 3:5 Hz, H2^b), 5.85 (m,

All); ¹³C NMR (CDCl₃, 75 MHz) ꢂ 21.1 (Ac), 67.9 (All), 68.6

(C2^b), 69.0 (C6^b), 69.3 (C6^a), 71.0 (C5^a), 74.2 (C2^a), 75.4

(C4^b), 75.5 (C4^a), 75.7 (C5^b), 79.1 (C3^a), 80.5 (C3^b), 97.3 (C1^a,

J_C1,H1¼ 171:6 Hz), 99.6 (C1^b, J_C1,H1¼ 152:0 Hz), 117.2, 133.8

(All), 170.5 (Ac). HRMS (FAB) Found: m=z 987.4274. Calcd

for C₅₉H₆₄NaO₁₂[M + Na]^þ: 987.4295.

system (100:1 ! 20:1), yielded 21 (279.7 mg, 80%); ½ꢁꢄ_D

+16^ꢂ(c 0.7, CHCl₃); ¹H NMR (CDCl₃, 300 MHz) ꢂ 1.85 (s,

Ac), 3.26 (ddd, J_4;5¼ 10:0 Hz, J_5;6a¼ 4:0 Hz, J_5;6b¼ 2:5 Hz,

H5^b), 3.50 (t, J_2;3¼ J_3;4¼ 9:5 Hz, H3^b), 3.54 (dd, J_5;6a¼ 4:0

Hz, J_6a,6b¼ 11:5 Hz, H6a^b), 3.57 (dd, J_5;6b¼ 2:5 Hz,

J_6a,6b¼ 11:5 Hz, H6b^b), 3.66 (dd, J_5;6a¼ 1:5 Hz, J_6a,6b¼ 10:0

Hz, H6a^a), 3.68 (ꢅt, J_3;4¼ 9:5 Hz, J_4;5¼ 10:0 Hz, H4^b), 3.69

(ddd, J_4;5¼ 9:0 Hz, J_5;6a¼ 1:5 Hz, J_5;6b¼ 4:5 Hz, H5^a), 3.73

(dd, J_1;2¼ 2:0 Hz, J_2;3¼ 3:0 Hz, H2^a), 3.80 (dd, J_5;6b¼ 4:5 Hz,

J_6a,6b¼ 10:0 Hz, H6b^a), 3.90 (dd, J_2;3¼ 3:0 Hz, J_3;4¼ 9:0 Hz,

H3^a), 4.22 (t, J_3;4¼ J_4;5¼ 9:0 Hz, H4^a), 4.53 (d, J_1;2¼ 8:0 Hz,

Before the elution of 23, there appeared the furanoid com-

pound, allyl 4-O-[(1R=S)-[1-acetoxy-2,5-anhydro-3,4,6-tri-O-ben-

zyl-^D-mannityl]]-2,3,6-tri-O-benzyl-ꢁ-D-mannopyranoside (9.8

mg, 12%); ½ꢁꢄ_D+20^ꢂ(c 0.4, CHCl₃); ¹H NMR (CDCl₃, 300

MHz) ꢂ 3.56 (dd, J_5;6a¼ 5:5 Hz, J_6a,6b¼ 10:0 Hz, H6a^b), 3.60

(dd, J_5;6b¼ 5:5 Hz, J_6a,6b¼ 10:0 Hz, H6b^b), 3.79 (dd, J_1;2¼ 2:0

Hz, J_2;3¼ 3:0 Hz, H2^a), 4.08 (dd, J_1;2¼ 4:5 Hz, J_2;3¼ 3:5 Hz,

H2^b), 4.30 (t, J_3;4¼ J_4;5¼ 9:5 Hz, H4^a), 4.35 (t,

J_2;3¼ J_3;4¼ 3:5 Hz, H3^b), 4.87 (d, J_1;2¼ 2:0 Hz, H1^a), 6.19 (d,

J_1;2¼ 4:5 Hz, H1^b); 1.78 (s, Ac), 5.88 (m, All); ¹³C NMR

(CDCl₃, 75 MHz) ꢂ 69.1 (C6^a), 69.8 (C6^b), 72.2 (C5^a), 75.7

(C2^a), 75.8 (C4^a), 78.2 (C3^a), 81.7 (C5^b), 83.1 (C2^b), 84.3

(C3^b), 84.7 (C4^b), 95.5 (C1^b), 97.4 (C1^a); 21.1, 170.3 (Ac);

67.9, 117.2, 133.8 (All). HRMS (FAB) Found: m=z 987.4337.

Calcd for C₅₉H₆₄NaO₁₂[M + Na]^þ: 987.4295.

H1^b), 4.86 (d, J_1;2¼ 2:0 Hz, H1^a), 4.94 (dd, J_1;2¼ 8:0 Hz, J_2;3

9:5 Hz, H2^b), 5.87 (m, All); ¹³C NMR (CDCl₃, 75 MHz) ꢂ 20.9

(Ac), 67.9 (All), 68.4 (C6^b), 68.7 (C6^a), 71.6 (C5^a), 73.8 (C2^b),

75.1 (2C, C4^aand C5^b), 75.4 (C2^a), 78.0 (C4^b), 78.5 (C3^a), 97.3

(C1^a, J_C1,H1¼ 167:0 Hz), 100.7 (C1^b, J_C1,H1¼ 158:2 Hz),

117.3, 133.8 (All), 169.5 (Ac). HRMS (FAB) Found: m=z

987.4336. Calcd for C₅₉H₆₄NaO₁₂[M + Na]^þ: 987.4295.

O-(2-O-Acetyl-3,4,6-tri-O-benzyl-ꢀ-D-mannopyranosyl)-

(1 ! 4)-2,3,6-tri-O-benzyl-^D-mannopyranose (4). A mixture

of 23 (64.7 mg, 0.067 mmol), PdCl₂(34.5 mg, 0.19 mmol),

NaOAc (62.2 mg, 0.76 mmol), and aq AcOH (95%, 2.7 mL)

was stirred at room temperature for 16 h. Evaporation and chro-

matography with the TK system (100:1 ! 10:1) gave 5 (35.9 mg,

Allyl

O-(3,4,6-Tri-O-benzyl-ꢀ-D-glucopyranosyl)-(1!4)-

2,3,6-tri-O-benzyl-ꢁ-D-mannopyranoside (22). A mixture of

21 (177.1 mg, 0.18 mmol), MeOH (10 mL), 1,4-dioxane (1

mL), and methanolic NaOMe (7%, 0.4 mL) was stirred at room

temperature overnight. Neutralization with AcOH, evaporation,

chromatography with the TK system (100:1 ! 20:1), and crystal-

58%); ½ꢁꢄ_Dꢁ6^ꢂ(c 0.4, CHCl₃); H NMR (CDCl₃, 300 MHz)

(75%ꢁ) ꢂ 2.10 (s, Acꢁ), 2.11 (s, Acꢀ), 2.70 (d, J_1;OH¼ 3:5 Hz,

OHꢁ), 3.26 (ddd, J_4;5¼ 9:5 Hz, J_5;6a¼ 2:0 Hz, J_5;6b¼ 4:5 Hz,

H5^bꢁ), 3.30 (m, H5^bꢀ), 3.44 (dd, J_5;6b¼ 4:5 Hz, J_5;6b¼ 4:5

Hz, H5^bꢁ), 3.46 (dd, J_2;3¼ 3:0 Hz, J_3;4¼ 9:0 Hz, H3^bꢀ), 3.50

(dd, J_5;6a¼ 2:0 Hz, J_6a,6b¼ 11:0 Hz, H6b^bꢁ), 3.58 (dd,

J_5;6b¼ 4:5 Hz, J_6a,6b¼ 11:0 Hz, H6b^bꢀ), 3.63 (dd, J_2;3¼ 3:0

Hz, J_3;4¼ 9:0 Hz, H3^aꢀ), 3.68 (dd, J_5;6a¼ 2:0 Hz, J_6a,6b¼ 10:0

Hz, H6a^aꢁ), 3.70 (ꢅt, J_1;2¼ 2:0 Hz, J_2;3¼ 3:0 Hz, H2^aꢁ), 3.72

(ꢅt, J_3;4¼ 9:0 Hz, J_4;5¼ 9:5 Hz, H4^bꢁ), 3.76 (dd, J_5;6b¼ 5:0

Hz, J_6a,6b¼ 10:0 Hz, H6b^aꢁ), 3.97 (dd, J_2;3¼ 3:0 Hz, J_3;4¼ 9:0

Hz, H3^aꢁ), 4.03 (ddd, J_4;5¼ 9:0 Hz, J_5;6a¼ 2:0 Hz, J_5;6b¼ 5:0

Hz, H5^aꢁ), 4.20 (t, J_3;4¼ J_4;5¼ 9:0 Hz, H4^aꢁ), 4.65 (s,

J_1;2¼ J_1;OH¼ 0 Hz, H1^aꢀ), 4.68 (s, J_1;2¼ 0 Hz, H1^bꢀ), 4.72

(s, J_1;2¼ 0 Hz, H1^bꢁ), 5.22 (dd, J_1;2¼ 2:0 Hz, J_1;OH¼ 3:5 Hz,

H1^aꢁ), 5.45 (d, J_1;2¼ 0 Hz, J_2;3¼ 3:0 Hz, H2^bꢀ),

5.46 (d, J_1;2¼ 0 Hz, J_2;3¼ 3:0 Hz, H2^blpha); ¹³C NMR (CDCl₃,

75 MHz) ꢂ 21.1 (Ac), 68.4 (C2^bꢁ), 68.5 (C2^bꢀ), 69.0 (C6^bꢁ),

69.1 (C6^bꢀ), 69.6 (C6^aꢁ and C6^aꢀ), 70.9 (C5^bꢁ), 74.1 (C4^bꢁ),

74.2 (C4^bꢀ), 74.5 (C2^aꢀ), 74.8 (C4^aꢀ), 75.4 (C2^aꢁ and C4^aꢁ),

75.6 (C5^bꢁ), 75.7 (C5^bꢀ), 76.6 (C5^aꢀ), 78.3 (C3^aꢁ), 80.4

(C3^bꢁ and C3^bꢀ), 81.5 (C3^aꢀ), 92.9 (C1^aꢁ, J_C1,H1¼ 170:0 Hz),

93.5 (C1^aꢀ, J_C1,H1¼ 159:1 Hz), 99.1 (C1^bꢀ, J_C1,H1¼ 158:0

Hz), 99.4 (C1^bꢁ, J_C1,H1¼ 156:0 Hz), 170.5 (Ac). HRMS

(FAB) Found: m=z 947.4012. Calcd for C₅₆H₆₀NaO₁₂[M +

Na]^þ: 947.3982.

ꢂ

lization from n-hexane gave 22 (149.0 mg, 88%); mp 87–88 C,

½ꢁꢄ_D+34^ꢂ(c 0.7, CHCl₃); ¹H NMR (CDCl₃, 300 MHz) ꢂ

3.27 (m, H5^b), 3.41 (dd, J_5;6a¼ 2:0 Hz, J_6a,6b¼ 10:5 Hz, H6a^a),

3.75 (dd, J_1;2¼ 2:0 Hz, J_2;3¼ 3:0 Hz, H2^a), 3.78 (t, J_3;4¼ J_4;5

9:0 Hz, H4^b), 3.84 (ddd, J_4;5¼ 9:0 Hz, J_5;6a¼ 2:0 Hz, J_5;6b¼ 4:0

Hz, H5^a), 3.97 (dd, J_2;3¼ 3:0 Hz, J_3;4¼ 9:0 Hz, H3^a), 4.36 (t,

J_3;4¼ J_4;5¼ 9:0 Hz, H4^a), 4.61 (d, J_1;2¼ 7:5 Hz, H1^b), 4.87 (d,

J_1;2¼ 2:0 Hz, H1 ), 5.85 (m, All); ¹³C NMR (CDCl₃, 75 MHz)

ꢂ 67.8 (All), 68.7 (C6^a), 69.7 (C6^b), 71.0 (C5^a), 74.7 (C4^a), 74.9

(C2^a), 75.1 (C5^b), 75.5 (C2^b), 77.2 (C4^b), 79.3 (C3^a), 84.4

(C3^b), 97.3 (C1^a, J_C1,H1¼ 169:0 Hz), 103.4 (C1^b,

J_C1,H1¼ 158:0 Hz), 117.2, 133.7 (All). Found: C, 73.89; H,

6.65%. Calcd for C₅₇H₆₂O₁₁: C, 74.16; H, 6.77%.

Allyl O-(2-O-Acetyl-3,4,6-tri-O-benzyl-ꢀ-D-mannopyrano-

syl)-(1 ! 4)-2,3,6-tri-O-benzyl-ꢁ-D-mannopyranoside (23).

Triﬂylation of 22 (77.9 mg, 0.084 mmol) with Tf₂O (277 mL,

1.7 mmol) and pyridine (181 mL, 2.2 mmol) in CH₂Cl₂(1.6

mL), quenching with H₂O (46 mL, 2.6 mmol) and subsequent

chromatography with the TK system (100:1 ! 10:1) were carried

out as described for 12 to give a syrup (79.2 mg). This was react-

ed with n-Bu₄NOAc (272 mg, 0.90 mmol) in anhydrous PhMe

ꢂ

(0.72 mL) with stirring at 50 C overnight, followed by chroma-

tography with the TK system (100:1 ! 10:1), to give 23 (59.0

mg, 72%); ½ꢁꢄ_D+10^ꢂ(c 0.8, CHCl₃); ¹H NMR (CDCl₃, 300

MHz) ꢂ 2.11 (s, Ac), 3.25 (ddd, J_4;5¼ 9:5 Hz, J_5;6a¼ 1:5 Hz,

J_5;6b¼ 5:0 Hz, H6^b), 3.44 (dd, J_2;3¼ 3:5 Hz, J_3;4¼ 9:5 Hz,

H3^b), 3.48 (dd, J_5;6a¼ 1:5 Hz, J_6a,6b¼ 11:0 Hz, H6a^b), 3.57

(dd, J_5;6b¼ 5:0 Hz, J_6a,6b¼ 11:0 Hz, H6b^b), 3.69 (dd,

J_5;6a¼ 3:5 Hz, J_6a,6b¼ 10:0 Hz, H6a^a), 3.71 (t, J_3;4¼ J_4;5¼ 9:5

Benzyl O-(2-O-Acetyl-3,4,6-tri-O-benzyl-ꢀ-D-mannopyrano-

syl)-(1 ! 4)-2,3,6-tri-O-benzyl-ꢁ-D-mannopyranosyl-(1 ! 3)-

2,4-di-O-benzyl-ꢁ-D-rhamnopyranoside (24). Condensation of

4 (25.5 mg, 0.028 mmol) and 6 (13.1 mg, 0.030 mmol) in the pres-

ence of NsCl (17.1 mg, 0.077 mmol), AgOTf (19.9 mg, 0.077

mmol), and DBU (11.5 mL, 0.077 mmol) in CH₂Cl₂(0.25 mL),

followed by quenching as above and chromatography with the

TK system (100:1 ! 10:1), aﬀorded 24 (13.1 mg, 35%) and

Hz, H4^b), 3.71 (dd, J_1;2¼ 2:0 Hz, J_2;3¼ 3:0 Hz, H2 ), 3.79

(ddd, J_4;5¼ 9:0 Hz, J_5;6a¼ 3:5 Hz, J_5;6b¼ 2:0 Hz, H5^a), 3.93

(dd, J_2;3¼ 3:0 Hz, J_3;4¼ 9:0 Hz, H3^a), 4.29 (t, J_3;4¼ J_4;5¼ 9:0

Hz, H4 ), 4.69 (d, J_1;2¼ 1:0 Hz, H1^b), 4.87 (d, J_1;2¼ 2:0 Hz,

S. Koto et al.

Bull. Chem. Soc. Jpn., 76, No. 8 (2003) 1611

the ꢀ-linked isomer (5.2 mg, 14%).

J_4;5¼ 9:5 Hz, H4^b), 4.53 (s, J_1;2¼ 0 Hz, H1^c), 4.84 (d, J_1;2¼ 2:0

Hz, H1^a), 4.97 (d, J_1;2¼ 2:0 Hz, H1^b); ¹³C NMR (CDCl₃, 75

MHz) ꢂ 18.0 (C6^a), 67.8 (C2^c), 68.2 (C5^a), 68.9 (C6^b), 69.0

(C6^c), 70.1 (C5^b), 73.6 (C4^b), 74.1 (2C, C3^aand C4^c), 74.3

(C2^b), 75.1 (C2^a), 75.7 (C5^c), 78.5 (C3^b), 79.6 (C4^a), 81.5

(C3^c), 94.4 (C1^a, J_C1,H1¼ 166:7 Hz), 96.7 (C1^b, J_C1,H1¼ 167:0

Hz), 100.1 (C1^c, J_C1,H1¼ 157:8 Hz). HRMS (FAB) Found:

m=z 1321.5830. Calcd for C₈₁H₈₆NaO₁₅[M + Na]^þ: 1321.5868.

O-ꢀ-D-Mannopyranosyl-(1 ! 4)-O-ꢁ-D-mannopyranosyl-

(1 ! 3)-ꢁ-L-rhamnopyranose (2). Hydrogenation of 25 (21.8

mg, 0.017 mmol) over Pd on C (10%, 34 mg) in AcOH (6 mL)

at room temperature, ﬁltration of the catalyst, concentration, and

chromatography with the EM system (100:1 ! 1:1) aﬀorded 2

24: ½ꢁꢄ_Dꢁ13^ꢂ(c 0.7, CHCl₃); ¹H NMR (CDCl₃, 400 MHz):

ꢂ 1.28 (q, J_5;6¼ 6:0 Hz, H6^a), 2.00 (s, Ac), 3.27 (ddd, J_4;5¼ 10:0

Hz, J_5;6a¼ 2:0 Hz, J_5;6b¼ 4:5 Hz, H5^c), 3.40 (dd, J_2;3¼ 3:5 Hz,

J_3;4¼ 9:5 Hz, H3^c), 3.50 (ꢅt, J_3;4¼ 9:0 Hz, J_4;5¼ 9:5 Hz, H4^a),

3.53 (dd, J_5;6a¼ 2:0 Hz, J_6a,6b¼ 11:5 Hz, H6a^c), 3.54 (dd, J_5;6a

2:0 Hz, J_6a,6b¼ 11:0 Hz, H6a^b), 3.60 (dd, J_5;6b¼ 3:0 Hz, J_6a,6b

11:0 Hz, H6b^b), 3.61 (dd, J_5;6b¼ 4:5 Hz, J_6a,6b¼ 11:5 Hz, H6b^c),

3.69 (ꢅt, J_1;2¼ 2:0 Hz, J_2;3¼ 3:0 Hz, H2^b), 3.72 (ꢅt, J_1;2¼ 2:0

Hz, J_2;3¼ 3:0 Hz, H2^a), 3.72 (ddd, J_4;5¼ 9:5 Hz, J_5;6¼ 6:0 Hz,

H5^a), 3.75 (ꢅt, J_3;4¼ 9:5 Hz, J_4;5¼ 10:0 Hz, H4^c), 3.91 (ꢅdt,

J_4;5¼ 9:5 Hz, J_5;6a¼ 2:0 Hz, J_5;6b¼ 3:0 Hz, H5^b), 3.98 (dd,

J_2;3¼ 3:0 Hz, J_3;4¼ 9:0 Hz, H3^b), 4.12 (dd, J_2;3¼ 3:0 Hz, J_3;4

9:0 Hz, H3 ), 4.40 (ꢅt, J_3;4¼ 9:0 Hz, J_4;5¼ 9:5 Hz, H4^b), 4.65 (s,

H1^c), 4.82 (d, J_1;2¼ 2:0 Hz, H1^a), 4.98 (d, J_1;2¼ 2:0 Hz, H1^b),

5.42 (d, J_1;2¼ 0 Hz, J_2;3¼ 3:5 Hz, H2^c); ¹³C NMR (CDCl₃, 75

MHz) ꢂ 18.0 (C6^a), 21.1 (Ac), 68.1 (C5^a), 68.5 (C2^c), 68.8

(C6^c), 68.9 (C6^b), 71.1 (C5^b), 74.2 (C4^c), 74.5 (C2^a), 74.6

(C3^a), 75.0 (C4^b), 75.8 (C5^c), 78.8 (C3^b), 79.7 (C4^a), 80.6

(C3^c), 94.9 (C1^b, J_C1,H1¼ 168:7 Hz), 96.8 (C1^a, J_C1,H1¼ 167:4

Hz), 99.5 (C1^c, J_C1,H1¼ 158:2 Hz), 170.4 (Ac). HRMS (FAB)

Found: m=z 1363.5999. Calcd for C₈₃H₈₈NaO₁₆[M + Na]^þ:

1363.5970.

(6.3 mg, 77%); ½ꢁꢄ_D+42^ꢂ(c 0.3, H₂O); ¹H NMR (D₂O, 400

MHz) (60%ꢁ) ꢂ 1.24 (d, J_5;6¼ 6:5 Hz, H1^bꢁ), 1.26 (d,

J_5;6¼ 6:0 Hz, H1^bꢀ), 3.40 (ddd, J_4;5¼ 9:5 Hz, J_5;6a¼ 6:5 Hz,

J_5;6b¼ 2:0 Hz, H5^c), 3.40 (dd, J_4;5¼ 8:5 Hz, J_5;6¼ 6:0 Hz,

H5^aꢀ), 3.40 (dd, J_3;4¼ 9:5 Hz, J_4;5¼ 8:5 Hz, H4^aꢀ), 3.45 (t,

J_3;4¼ J_4;5¼ 9:5 Hz, H4^aꢁ), 3.52 (t, J_3;4¼ J_4;5¼ 9:5 Hz, H4^c),

3.62 (dd, J_2;3¼ 3:0 Hz, J_3;4¼ 9:5 Hz, H3^c), 3.67 (dd,

J_2;3¼ 3:5 Hz, J_3;4¼ 9:5 Hz, H3^aꢀ), 3.69 (dd, J_5;6a¼ 6:5 Hz,

J_6a,6b¼ 12:0 Hz, H6a^c), 3.73 (dd, J_5;6a¼ 3:0 Hz, J_6a,6b¼ 12:0

Hz, H6a^bꢀ), 3.74 (dd, J_5;6a¼ 4:0 Hz, J_6a,6b¼ 12:0 Hz, H6a^bꢁ),

3.80 (dd, J_5;6b¼ 2:0 Hz, J_6a,6b¼ 12:0 Hz, H6b^bꢀ), 3.81 (dd,

J_5;6b¼ 2:0 Hz, J_6a,6b¼ 12:0 Hz, H6b^bꢁ), 3.84 (dd, J_2;3¼ 3:0

The ꢀ-linked isomer: ½ꢁꢄ_Dꢁ58^ꢂ(c 0.5, CHCl₃); ¹H NMR

(CDCl₃, 300 MHz): ꢂ 1.33 (q, J_5;6¼ 6:0 Hz, H6 ), 2.13 (s, Ac),

3.23 (ddd, J_4;5¼ 9:5 Hz, J_5;6a¼ 2:0 Hz, J_5;6b¼ 4:5 Hz, H5^c),

3.37 (dd, J_2;3¼ 3:0 Hz, J_3;4¼ 9:5 Hz, H3^b), 3.42 (dd,

J_5;6a¼ 2:0 Hz, J_6a,6b¼ 11:0 Hz, H6a^c), 3.43 (ddd, J_4;5¼ 9:5

Hz, J_5;6a¼ 6:0 Hz, J_5;6b¼ 5:0 Hz, H5^b), 3.46 (t,

J_3;4¼ J_4;5¼ 9:0 Hz, H4^a), 3.48 (dd, J_2;3¼ 3:0 Hz, J_3;4¼ 9:5

Hz, H3^c), 3.55 (dd, J_5;6b¼ 4:5 Hz, J_6a,6b¼ 11:0 Hz, H6b^c),

3.60 (t, J_3;4¼ J_4;5¼ 9:5 Hz, H4^b), 3.73 (dd, J_5;6a¼ 6:0 Hz,

J_6a,6b¼ 11:0 Hz, H6a^b), 3.74 (m, H5^a), 3.75 (t, J_3;4¼ J_4;5¼ 9:5

Hz, H4^c), 3.79 (dd, J_5;6b¼ 5:0 Hz, J_6a,6b¼ 11:0 Hz, H6b^b),

Hz, J_3;4¼ 9:5 Hz, H3 ꢁ), 3.84 (dq, J_4;5¼ 9:5 Hz, J_5;6¼ 6:5

Hz, H5^aꢁ), 3.88 (dd, J_2;3¼ 3:5 Hz, J_3;4¼ 9:0 Hz, H3^bꢀ), 3.91

(dd, J_5;6b¼ 2:0 Hz, J_6a,6b¼ 12:0 Hz, H6b^c), 3.91 (t, J_3;4¼ J_4;5

9:5 Hz, H4^bꢀ), 3.92 (t, J_3;4¼ J_4;5¼ 9:5 Hz, H4^bꢁ), 3.94 (m,

H5^bꢁ), 3.95 (m, H5^bꢀ), 4.00 (dd, J_2;3¼ 3:5 Hz, J_3;4¼ 9:5 Hz,

H3^bꢁ), 4.02 (d, J_1;2¼ 0 Hz, J_2;3¼ 3:0 Hz, H2^c), 4.02 (dd, J_1;2

1:5 Hz, J_2;3¼ 3:5 Hz, H2^bꢁ), 4.03 (dd, J_1;2¼ 1:5 Hz, J_2;3¼ 3:5

Hz, H2^bꢀ), 4.10 (dd, J_1;2¼ 2:0 Hz, J_2;3¼ 3:0 Hz, H2^aꢁ), 4.12 (d,

J_1;2¼ 0 Hz, J_2;3¼ 3:5 Hz, H2^aꢀ), 4.71 (s, H1^c), 4.81 (s, H1^aꢀ),

4.99 (d, J_1;2¼ 1:5 Hz, H1^bꢁ), 5.01 (d, J_1;2¼ 1:5 Hz, H1^bꢀ),

5.10 (d, J_1;2¼ 2:0 Hz, H1^aꢁ); ¹³C NMR (CDCl₃, 100 MHz) ꢂ

18.7 (C6^aꢀ), 18.8 (C6^aꢁ), 62.1 (C6^b), 62.9 (C6^c), 68.6 (C2^aꢁ

and C4^c), 69.1 (C2^aꢀ), 70.1 (C5^aꢁ), 71.0 (C3^b), 71.6 (C2^bꢀ),

71.7 (C2^bꢁ), 72.0 (C4^aꢀ), 72.3 (C4^aꢁ), 72.4 (C2^c), 73.0 (C5^b),

73.8 (C5^aꢀ), 74.7 (C3^c), 75.4 (C3^b), 76.1 (C3^aꢁ), 78.3 (C5^c),

78.4 (C3^aꢀ and C4^b), 95.3 (C1^aꢀ, J_C1,H1¼ 160:0 Hz), 95.7

(C1^aꢁ, J_C1,H1¼ 170:0 Hz), 97.9 (C1^bꢀ, J_C1,H1¼ 170:0 Hz),

98.0 (C1^bꢁ, J_C1,H1¼ 169:5 Hz), 102.0 (C1^c, J_C1,H1¼ 159:0

3.99 (t, J_1;2¼ J_2;3¼ 3:0 Hz, H2^b), 4.10 (ꢅt, J_1;2¼ 2:0 Hz, J_2;3

3:0 Hz, H2^a), 4.56 (d, J_1;2¼ 3:0 Hz, H1^b), 4.74 (d, J_1;2¼ 2:0 Hz,

H1^a), 4.77 (s, J_1;2¼ 0 Hz, H1^c), 5.50 (d, J_1;2¼ 0 Hz, J_2;3¼ 3:0

Hz, H2^c); ¹³C NMR (CDCl₃, 75 MHz) ꢂ 18.0 (C6^a), 21.2 (Ac),

68.1 (C5^a), 68.5 (C2^c), 68.8 (C6^c), 69.5 (C6^b), 74.0 (C4^c), 74.9

(C4^a), 75.0 (C4^b), 75.2 (C5^b), 75.6 (C5^c), 78.3 (C2^b), 80.5

(C3^c), 81.1 (C3^a), 81.4 (C3^b), 81.6 (C2^a), 98.3 (C1^a,

J_C1,H1¼ 169:5 Hz), 99.7 (C1^c, J_C1,H1¼ 157:8 Hz), 103.6 (C1^b,

J_C1,H1¼ 155:8 Hz), 170.5 (Ac). HRMS (FAB) Found: m=z

1363.6017. Calcd for C₈₃H₈₈NaO₁₆[M + Na]^þ: 1363.5970.

Hz).

HRMS (FAB) Found: m=z 511.1662.

Calcd for

Benzyl

(1 ! 4)-2,3,6-tri-O-benzyl-ꢁ-D-mannopyranosyl-(1 ! 3)-2,4-

di-O-benzyl-ꢁ-D-rhamnopyranoside (25). A mixture of 24

O-(3,4,6-Tri-O-benzyl-ꢀ-D-mannopyranosyl)-

C₁₈H₃₂NaO₁₅[M + Na]^þ: 511.1639.

Allyl ꢁ-D-Galactopyranoside (26). A mixture of D-galactose

(5 g, 0.028 mmol), allyl alcohol (80 mL, 1.2 mmol), and MeSO₃H

ꢂ

(25.2 mg, 0.019mmol), MeOH (4.0 mL), 1,4-dioxane (0.40 mL),

and dil NaOMe (7%, 0.3 mL) was stirred at room temperature

overnight. After neutralization with AcOH, evaporation and chro-

matography with the TK system (100:1 ! 20:1) produced 25

(0.20 mL, 3.1 mmol) was stirred at 100 C for 2 h under reﬂux.

After the addition of NaHCO₃(0.30 g, 3.6 mmol), the mixture

was evaporated. Chromatography with the EM system (100:1

! 2:1), followed by crystallization with a seed and diisopropyl

ether containing MeOH (5%), gave 26 (2.1 g, 34%); mp 140–

(22.4 mg, 92%); ½ꢁꢄ_D+13^ꢂ(c 0.8, CHCl₃); H NMR (CDCl₃,

300 MHz) ꢂ 1.33 (d, J_5;6¼ 6:0 Hz, H6^a), 2.32 (s, OH), 3.25 (dt,

J_4;5¼ 9:5 Hz, J_5;6a¼ J_5;6b¼ 3:0 Hz, H5^c), 3.32 (dd, J_2;3¼ 3:0

Hz, J_3;4¼ 9:5 Hz, H3^c), 3.50 (dd, J_3;4¼ 3:0 Hz, J_4;5¼ 9:5 Hz,

142 ^ꢂC, ½ꢁꢄ_D+173^ꢂ(c 0.8, H₂O) (Ref. 15a, mp 138–142 ^ꢂC,

½ꢁꢄ_D+171.7^ꢂ(H₂O); Ref. 15b, mp 145–146 ^ꢂC, ½ꢁꢄ_D

+185.0^ꢂ(c 5.8, H₂O); Ref. 15c, mp 143–145 ^ꢂC, ½ꢁꢄ_D

+181.3^ꢂ(c 1.57, H₂O), Ref. 15e, mp 143–143.5 ^ꢂC, ½ꢁꢄ_D

H4^a), 3.53 (d, J_5;6a¼ J_5;6b¼ 3:0 Hz, H6^b), 3.65 (d, J_5;6a¼ J_5;6b

3:0 Hz, H6^c), 3.72 (dd, J_1;2¼ 2:0 Hz, J_2;3¼ 3:0 Hz, H2^a), 3.74

(dd, J_1;2¼ 2:0 Hz, J_2;3¼ 3:0 Hz, H2^b), 3.75 (dq, J_3;4¼ 9:5 Hz,

J_4;5¼ 6:0 Hz, H5^a), 3.83 (d, J_1;2¼ 0 Hz, J_2;3¼ 3:0 Hz, H2^c),

+181.4^ꢂ(c 5.8, H₂O)). HRMS (FAB) Found: m=z 243.0853.

Calcd for C₉H₁₆NaO₆[M + Na]^þ: 243.0845.

Benzyl ꢁ-D-Galactopyranoside (27). A mixture of D-galac-

tose (1.0 g, 5.6 mmol), BnOH (2.0 mL, 19 mmol), and MeSO₃H

(0.20 mL, 3.1 mmol), instead of p-toluenesulfonic acid monohy-

3.89 (dt, J_4;5¼ 9:5 Hz, J_5;6a¼ J_5;6b¼ 3:0 Hz, H5^b), 3.90 (t, J_3;4

J_4;5¼ 9:5 Hz, H4^c), 3.96 (dd, J_2;3¼ 3:0 Hz, J_3;4¼ 9:5 Hz, H3^b),

4.12 (dd, J_2;3¼ 3:0 Hz, J_3;4¼ 9:5 Hz, H3^a), 4.36 (t, J_3;4¼ 9:0 Hz,

drate,¹⁹was strongly stirred at 90 C for 25 min. After the addi-

ꢂ

1612 Bull. Chem. Soc. Jpn., 76, No. 8 (2003)

Synthesis of ꢀ-Mannoside and ꢀ-Mannosaminide

O-(2-O-Acetyl-3,4,6-tri-O-benzyl-ꢀ-D-glucopyrano-

tion of Et₃N (1.6 mL, 11 mmol), the mixture was diluted with

CHCl₃(5 mL) and chromatographed with the CM system

Allyl

syl)-(1 ! 4)-2,3,6-tri-O-benzyl-ꢁ-D-galactopyranoside

(28).

(100:1 ! 2:1) to give 27 (0.99 g, 66%); ½ꢁꢄ_D+158^ꢂ(c 0.7,

Condensation of 1 (207.7 mg, 0.42 mmol) and 8 (159.1 mg,

0.32 mmol) in the presence of NsCl (179.8 mg, 0.81 mmol),

AgOTf (208.6 mg, 0.81 mmol), and DBU (120.9 mL, 0.81 mmol)

in CH₂Cl₂(1.6 mL), followed by quenching and chromatography

with the TK system (100:1 ! 20:1) as described above, yielded

MeOH); ¹H NMR (D₂O, 300 MHz) ꢂ 3.64 (dd, J_5;6a¼ 5:0 Hz,

J_6a,6b¼ 11:5 Hz, H6a), 3.68 (dd, J_5;6b¼ 5:0 Hz, J_6a,6b¼ 11:5

Hz, H6b), 3.75 (dd, J_1;2¼ 3:0 Hz, J_2;3¼ 10:0 Hz, H2), 3.82

(dd, J_2;3¼ 10:0 Hz, J_3;4¼ 3:0 Hz, H3), 3.90 (dt, J_4;5¼ 1:0 Hz,

J_5;6a¼ J_5;6b¼ 5:0 Hz, H5), 3.93 (dd, J_3;4¼ 3:0 Hz, J_4;5¼ 1:0

Hz, H4), 4.57 (d, J ¼ 12:0 Hz, Bn), 4.72 (d, J ¼ 12:0 Hz, Bn),

5.01 (d, J_1;2¼ 3:0 Hz, H1); ¹³C NMR (D₂O, 75 MHz) ꢂ 63.8

(C6), 70.9 (C2), 71.9 (C4), 72.1 (C3), 72.3 (Bn), 73.7 (C5),

100.5 (C1), 130.9, 131.1 (2C), 131.4 (2C), 139.7 (Bn). HRMS

(FAB) Found: m=z 293.1001. Calcd for C₁₃H₁₈NaO₆[M +

Na]^þ: 293.1001.

28 (300.9 mg, 96%); ½ꢁꢄ_D+40^ꢂ(c 0.8, CHCl₃); ¹H NMR

(CDCl₃, 300 MHz): ꢂ 1.75 (s, Ac), 3.39 (ddd, J_4;5¼ 9:5 Hz,

J_5;6a¼ 4:0 Hz, J_5;6b¼ 2:0 Hz, H5^b), 3.65 (dd, J_5;6a¼ 4:0 Hz,

J_6a,6b¼ 10:5 Hz, H6a^b), 3.65 (t, J_2;3¼ J_3;4¼ 9:0 Hz, H3^b), 3.68

(ꢅt, J_3;4¼ 9:0 Hz, J_4;5¼ 9:5 Hz, H4^b), 3.72 (dd, J_5;6b¼ 2:0

Hz, J_6a,6b¼ 10:5 Hz, H6b^b), 3.81 (dd, J_1;2¼ 3:0 Hz, J_2;3¼ 10:0

Hz, H2^a), 3.82 (dd, J_5;6b¼ 6:0 Hz, J_6a,6b¼ 10:0 Hz, H6b^a), 3.90

(dd, J_2;3¼ 10:0 Hz, J_3;4¼ 2:5 Hz, H3^a), 3.96 (ꢅt, J_4;5¼ 1:0

Allyl 2,3,6-Tri-O-benzyl-ꢁ-D-galactopyranoside (8). A mix-

ture of 26 (0.950 g, 4.3 mmol), BnCl (19 mL, 0.17 mol), and

LiOH (0.829 g, 35 mmol) was stirred strongly at 140 ^ꢂC for 4

h. The mixture was evaporated at 90 ^ꢂC and chromatographed

with the TK system (100:1 ! 20:1) to give 8 (0.83 g, 39%);

Hz, J_5;6a¼ J_5;6b¼ 6:0 Hz, H5 ), 4.08 (dd, J_3;4¼ 2:5 Hz,

J_4;5¼ 1:0 Hz, H4^a), 4.70 (d, J_1;2¼ 7:5 Hz, H1^b), 4.86 (d,

J_1;2¼ 3:0 Hz, H1^a), 5.01 (dd, J_1;2¼ 7:5 Hz, J_2;3¼ 9:0 Hz,

H2^b), 5.93 (m, All); ¹³C NMR (CDCl₃, 75 MHz) ꢂ 20.9 (Ac),

68.2 (All), 69.0 (C6^b), 69.6 (C5^a), 70.2 (C6^a), 73.2 (C2^b), 74.8

(C5^b), 75.7 (C4^a), 77.0 (C2^a), 77.8 (C4^b), 78.2 (C3^a), 83.1

(C3^b), 95.9 (C1^a), 101.0 (C1^b), 117.9, 134.0 (All), 169.6 (Ac).

Found: C, 73.08; H, 6.75%. Calcd for C₅₉H₆₄O₁₂: C, 73.42; H,

6.68%.

½ꢁꢄ_D+54^ꢂ(c 0.8, CHCl₃) (Ref. 14a, ½ꢁꢄ_D+52.8^ꢂ(c 1,

CHCl₃), Ref. 14b, ½ꢁꢄ_D²⁵+42^ꢂ(c 2.4, CHCl₃)); ¹H NMR (CDCl₃,

300 MHz) ꢂ 2.00 (s, OH), 3.67 (dd, J_5;6a¼ 6:0 Hz, J_6a,6b¼ 10:0

Hz, H6a), 3.74 (dd, J_5;6b¼ 6:0 Hz, J_6a,6b¼ 10:0 Hz, H6b), 3.88

(dd, J_1;2¼ 3:0 Hz, J_2;3¼ 10:0 Hz, H2), 3.91 (dd, J_2;3¼ 10:0

Hz, J_3;4¼ 3:0 Hz, H3), 3.95 (ꢅdt, J_4;5ꢅ 1:0 Hz,

J_5;6a¼ J_5;6b¼ 6:0 Hz, H5), 4.09 (ꢅd, J_3;4¼ 3:0 Hz, J_4;5ꢅ 1:0

Hz, H4), 4.88 (d, J_1;2¼ 3:0 Hz, H1); 5.95 (m, All); ¹³C NMR

(CDCl₃, 75 MHz) ꢂ 68.1 (C4), 68.3 (All), 68.5 (C5), 69.5 (C6),

75.7 (C2), 77.6 (C3), 96.1 (C1), 118.0, 133.8 (All). HRMS

(FAB) Found: m=z 513.2275. Calcd for C₃₀H₃₄NaO₆[M +

Na]^þ: 513.2253.

Allyl O-(3,4,6-Tri-O-benzyl-ꢀ-D-glucopyranosyl)-(1 ! 4)-

2,3,6-tri-O-benzyl-ꢁ-D-galactopyranoside (29). A mixture of

28 (290 mg, 0.30 mmol), MeOH (10 mL), and methanolic NaOMe

(7%, 0.4 mL) was stirred at 35 ^ꢂC overnight. After neutralization

with AcOH, evaporation and chromatography with the TK system

(100:1 ! 10:1) gave 29 (258.3 mg, 93%); ½ꢁꢄ_D+29^ꢂ(c 0.4,

CHCl₃); ¹H NMR (CDCl₃, 300 MHz) ꢂ 3.40 (ddd, J_4;5¼ 9:0

Hz, J_5;6a¼ 2:5 Hz, J_5;6b¼ 4:0 Hz, H5^b), 3.50 (t,

J_3;4¼ J_4;5¼ 9:0 Hz, H4^b), 3.54 (t, J_2;3¼ J_3;4¼ 9:0 Hz, H3^b),

3.60 (dd, J_1;2¼ 7:5 Hz, J_2;3¼ 9:0 Hz, J_2;OH¼ 0 Hz, H2^b), 4.05

(br d, J_3;4¼ 3:0 Hz, J_4;5ꢅ 1:0 Hz, H4^a), 4.32 (d, J_1;2¼ 7:5 Hz,

H1^b), 4.87 (d, J_1;2¼ 3:5 Hz, H1^a), 5.92 (m, All); ¹³C NMR

(CDCl₃, 75 MHz) ꢂ 68.7 (C5^a), 68.4 (All), 68.8 (C6^a), 69.4

(C6^b), 75.4 (C5^b), 76.1 (C2^b), 76.8 (C2^a), 77.1 (C4^b), 77.8

(C3^a), 79.7 (C4^a), 84.8 (C3^b), 96.0 (C1^a), 106.0 (C1^b), 118.0,

NMR data of the acetate: H NMR (CDCl₃, 300 MHz) ꢂ 2.06

(s, Ac), 3.47 (dd, J_5;6a¼ 6:0 Hz, J_6a,6b¼ 10:0 Hz, H6a), 3.52 (dd,

J_5;6b¼ 6:0 Hz, J_6a,6b¼ 10:0 Hz, H6b), 3.79 (dd, J_1;2¼ 4:0 Hz,

J_2;3¼ 10:0 Hz, H2), 3.99 (dd, J_3;4¼ 10:0 Hz, J_3;4¼ 3:5 Hz,

H3), 4.13 (dt, J_4;5¼ 1:0 Hz, J_5;6a¼ J_5;6b¼ 6:0 Hz, H5), 4.90

(d, J_1;2¼ 4:0 Hz, H1), 5.63 (dd, J_3;4¼ 3:5 Hz, J_4;5¼ 1:0 Hz,

H4), 5.94 (m, All); ¹³C NMR (CDCl₃, 75 MHz) ꢂ 20.9 (Ac),

67.8 (C5), 68.3 (C4), 68.5 (2C, C6 and All), 75.5 (C2), 76.3

(C3), 96.4 (C1), 118.1, 133.7 (All), 170.3 (Ac).

133.8 (All). Found: C, 72.78; H, 6.72%. Calcd for

C₅₇H₆₂O₁₁H₂O: C, 72.74; H, 6.85%.

Benzyl 2,3,6-Tri-O-benzyl-ꢁ-D-galactopyranoside (9).

ꢃ

mixture of 27 (0.756 g, 2.8 mol), BnCl (15 mL, 0.13 mol), and

LiOH (0.538 g, 22 mmol) was stirred strongly at 140 ^ꢂC for 4

h. Evaporation at 90 ^ꢂC and chromatography with the TK system

Allyl O-(2-Azido-3,4,6-tri-O-benzyl-2-deoxy-ꢀ-D-mannopy-

ranosyl)-(1 ! 4)-2,3,6-tri-O-benzyl-ꢁ-D-galactopyranoside

(30). Triﬂylation of 29 (86.0 mg, 0.093 mmol) with Tf₂O (284.6

mL, 1.74 mmol) and pyridine (186.8 mL, 2.3 mmol) in CH₂Cl₂

(1.6 mL), followed by quenching with H₂O (47 mL, 2.6 mmol),

dilution with hexane (5 mL), and chromatography with the TK

system (100:1 ! 10:1), aﬀorded a syrup (88.2 mg). This was dis-

solved in anhydrous PhMe (2.1 mL). To the obtained solution,

CsN₃(109.8 mg, 0.63 mmol) and 18-crown-6 (165.9 mg, 0.63

mmol) were added; the resulting mixture was ultrasonicated for

11 h at ca. 60 ^ꢂC. The mixture was diluted with hexane and chro-

matographed with the TK system (100:1 ! 10:1) to give 30 (40.0

(100:1 ! 20:1) gave 9 (0.612 g, 40%); ½ꢁꢄ_D+72^ꢂ(c 1.0,

CHCl₃); (Ref. 18, ½ꢁꢄ_Dþ 69:0^ꢂ(c 0.6, CHCl₃)); ¹H NMR

(CDCl₃, 300 MHz) ꢂ 2.60 (s, OH), 3.64 (dd, J_5;6a¼ 6:0 Hz,

J_6a,6b¼ 10:0 Hz, H6a), 3.73 (dd, J_5;6b¼ 6:0 Hz, J_6a,6b¼ 10:0

Hz, H6b), 3.87 (dd, J_1;2¼ 3:5 Hz, J_2;3¼ 10:0 Hz, H2), 3.94

(dd, J_2;3¼ 10:0 Hz, J_3;4¼ 3:0 Hz, H3), 3.99 (ꢅt, J_4;5¼ 1:5 Hz,

J_5;6a¼ J_5;6b¼ 6:0 Hz, H5), 4.10 (dd, J_3;4¼ 3:0 Hz, J_4;5¼ 1:5

Hz, J_4;OH¼ 0 Hz, H4), 4,90 (d, J_1;2¼ 3:5 Hz, H1); ¹³C NMR

(CDCl₃, 75 MHz) ꢂ 68.1 (C4), 68.7 (C5), 69.6 (C6), 75.8 (C2),

77.8 (C3), 96.0 (C1). HRMS (FAB) Found: m=z 563.2380. Calcd

for C₃₄H₃₆NaO₆[M + Na]^þ: 563.2410.

mg, 45%); ½ꢁꢄ_D+15^ꢂ(c 0.8, CHCl₃); ¹H NMR (CDCl₃, 300

MHz) ꢂ 3.27 (ddd, J_4;5¼ 9:0 Hz, J_5;6a¼ 2:0 Hz, J_5;6¼ 4:5 Hz,

H6a^b), 3.39 (dd, J_2;3¼ 3:0 Hz, J_3;4¼ 9:0 Hz, H3^b), 3.62 (dd,

J_5;6a¼ 2:0 Hz, J_6a,6b¼ 11:0 Hz, H6a^b), 3.69 (t, J_3;4¼ J_4;5¼ 9:0

Hz, H4^b), 3.70 (dd, J_5;6a¼ 9:0 Hz, J_6a,6b¼ 10:0 Hz, H6a^a), 3.82

(dd, J_5;6b¼ 6:0 Hz, J_6a,6b¼ 11:0 Hz, H6b^a), 4.00 (ꢅt, J_4;5¼ 1:0

NMR data of the acetate: H NMR (CDCl₃, 300 MHz) ꢂ 2.05

(s, Ac), 3.46 (2H, d, J_5;6¼ 6:0 Hz, H6), 3.78 (d, J_1;2¼ 4:0 Hz,

J_2;3¼ 10:0 Hz, H2), 4.03 (dd, J_2;3¼ 10:0 Hz, J_3;4¼ 3:5 Hz,

H3), 4.15 (dt, J_4;5¼ 1:0 Hz, J_5;6¼ 6:0 Hz, H5), 4.91 (d,

J_1;2¼ 4:0 Hz, H1), 5.64 (dd, J_3;4¼ 3:5 Hz, J_4;5¼ 1:0 Hz, H4);

¹³C NMR (CDCl₃, 75 MHz) ꢂ 20.9 (Ac), 67.9 (C5), 68.2 (C4),

68.5 (C6), 75.6 (C2), 76.4 (C3), 96.1 (C1), 170.3 (Ac).

Hz, J_5;6a¼ J_5;6b¼ 6:0 Hz, H5 ), 4.03 (dd, J_1;2¼ 1:0 Hz,

J_2;3¼ 3:0 Hz, H2^b), 4.20 (dd, J_3;4¼ 3:0 Hz, J_4;5¼ 1:0 Hz,

H4^a), 4.73 (d, J_1;2¼ 1:0 Hz, H1^b), 4.85 (d, J_1;2¼ 3:0 Hz, H1^a),

S. Koto et al.

Bull. Chem. Soc. Jpn., 76, No. 8 (2003) 1613

5.93 (m, All); ¹³C NMR (CDCl₃, 75 MHz) ꢂ 61.7 (C2^b), 68.3

MHz) ꢂ 61.6 (C2^bꢀ), 61.7 (C2^bꢁ), 69.15 (C5^aꢁ), 69.24 (C6^b),

69.46 (C6^aꢀ), 69.50 (C6^aꢁ), 74.1 (C4^bꢁ), 75.7 (C5^bꢁ), 75.9

(C4^aꢁ), 76.6 (C2^aꢁ), 77.7 (C3^aꢁ), 81.2 (C3^bꢁ), 81.4 (C3^aꢀ),

91.6 (C1^aꢁ, J_C1,H1¼ 168:0 Hz), 97.8 (C1^aꢀ, J_C1,H1¼ 156:7

Hz), 100.4 (C1^bꢀ, J_C1,H1¼ 159:0 Hz), 100.9 (C1^bꢁ,

J_C1,H1¼ 157:5 Hz). HRMS (FAB) Found: m=z 930.3928. Calcd

for C₅₄H₅₇N₃NaO₁₀[M + Na]^þ: 930.3942.

(All), 69.2 (C5^a), 69.3 (C6^b), 69.5 (C6^a), 74.2 (C4^b), 75.8 (C5^b),

76.3 (C4^a), 76.6 (C2^a), 78.1 (C3^a), 81.3 (C3^b), 96.0 (C1^a, J_C1,H1

170:0 Hz), 101.0 (C1^b, J_C1,H1¼ 158:0 Hz), 118.0, 134.0 (All).

Found: C, 72.10; H, 6.60; N, 4.40%. Calcd for C₅₇H₆₁N₃O₁₀: C,

72.21; H, 6.49; N, 4.43%.

Condensation of 31 (48 mg, 0.10 mmol), of which a new prep-

aration method is described below, and 8 (38 mg, 0.78 mmol) in

the presence of NsCl (43 mg, 0.19 mmol), AgOTf (50 mg, 0.19

mmol), and Et₃N (27 mL, 19 mmol) in CH₂Cl₂(0.38 mL), fol-

lowed by quenching with NaHCO₃and PhMe as above and chro-

matography with the TK system (100:1 ! 10:1), aﬀorded the ꢁ-

linked isomer, allyl O-(2-azido-3,4,6-tri-O-benzyl-2-deoxy-ꢁ-D-

mannopyranosyl)-(1 ! 4)-2,3,6-tri-O-benzyl-ꢁ-D-galactopyrano-

side, (39 mg, 53%) and then 30 (19 mg, 26%) (ꢀ:ꢁ = 33:67).

Benzyl O-(2-Azido-3,4,6-tri-O-benzyl-2-deoxy-ꢀ-D-manno-

pyranosyl)-(1 ! 4)-2,3,6-tri-O-benzyl-ꢁ-D-galactopyranosyl-

(1 ! 4)-2,3,6-tri-O-benzyl-ꢁ-D-galactopyranoside (32). Con-

densation of 7 (41.1 mg, 0.045 mmol) and 9 (31.9 mg, 0.059

mmol) in the presence of NsCl (30.1 mg, 0.14 mmol), AgOTf

(34.9 mg, 0.14 mmol), DMA (12.6 mL, 0.14 mmol), and Et₃N

(19.0 mL, 0.14 mmol) in CH₂Cl₂(0.40 mL), followed by quench-

ing as above and chromatography with the TK system (100:1 !

The ꢁ-linked isomer: ½ꢁꢄ_D+53^ꢂ(c 0.6, H₂O); ¹H NMR

10:1), aﬀorded 32 (36.0 mg, 56%); ½ꢁꢄ_D+44^ꢂ(c 0.8, CHCl₃);

(CDCl₃, 300 MHz) ꢂ 3.05 (dd, J_5;6a¼ 1:5 Hz, J_6a,6b¼ 10:5 Hz,

H6a^a), 3.46 (dd, J_5;6b¼ 5:5 Hz, J_5;6¼ 9:0 Hz, H6b^b), 3.81 (dd,

¹H NMR (CDCl₃, 400 MHz) ꢂ 3.23 (ddd, J_4;5¼ 9:5 Hz,

J_5;6a¼ 1:5 Hz, J_5;6b¼ 4:5 Hz, H5^c), 3.32 (dd, J_2;3¼ 3:5 Hz,

J_3;4¼ 9:5 Hz, H3^c), 3.55 (dd, J_5;6a¼ 1:5 Hz, J_6a,6b¼ 11:0 Hz,

H6a^c), 3.64 (dd, J_5;6b¼ 4:5 Hz, J_5;6a¼ 11:0 Hz, H6b^c), 3.70 (t,

J_3;4¼ J_4;5¼ 9:5 Hz, H2^a), 3.88 (dd, J_1;2¼ 3:0 Hz, J_2;3¼ 10:0

Hz, H2^a), 3.88 (dd, J_2;3¼ 10:0 Hz, J_3;4¼ 2:5 Hz, H3^b), 3.92

(dd, J_2;3¼ 10:0 Hz, J_3;4¼ 2:5 Hz, H3^a), 3.99 (d, J_1;2¼ 1:5 Hz,

J_2;3¼ 3:5 Hz, H2^c), 4.00 (dd, J_1;2¼ 3:5 Hz, J_2;3¼ 10:0 Hz,

J_1;2¼ 3:5 Hz, J_2;3¼ 9:0 Hz, H2^a), 3.82 (dd, J_1;2¼ 1:5 Hz, J_2;3

3:0 Hz, H2^b), 3.92 (dd, J_2;3¼ 3:0 Hz, J_3;4¼ 10:0 Hz, H3^b), 4.02

(ꢅt, J_3;4¼ 10:0 Hz, J_4;5¼ 9:5 Hz, H4^b), 4.18 (d, J_3;4¼ 2:5 Hz,

J_4;5¼ 0 Hz, H4^a), 4.82 (d, J_1;2¼ 3:5 Hz, H1^a), 4.90 (d,

J_1;2¼ 1:5 Hz, H1^b); 5.92 (m, All); ¹³C NMR (CDCl₃, 75 MHz)

ꢂ 61.7 (C2^b), 67.7 (C6^a), 67.9 (C6^b), 68.6 (C5^b), 71.8 (C5^a),

74.2 (C4^b), 74.9 (C2^a), 75.6 (C4^a), 77.0 (C3^a), 79.9 (C3^b), 99.5

(C1^a, J_C1,H1¼ 170:0 Hz), 96.3 (C1^b, J_C1,H1¼ 169:0 Hz); 68.4,

118.1, 133.8 (All). HRMS (FAB) Found: m=z 970.4275. Calcd

for C₅₇H₆₁N₃NaO₁₀[M + Na]^þ: 970.4255.

H2^b), 4.09 (dd, J_3;4¼ 2:5 Hz, J_3;4¼ 1:0 Hz, H4^a), 4.28 (dd, J_3;4

2:5 Hz, J_4;5¼ 1:0 Hz, H4^b), 4.62 (d, J_1;2¼ 1:5 Hz, H1^c), 4.91 (d,

J_1;2¼ 3:0 Hz, H1^a), 5.04 (d, J_1;2¼ 3:5 Hz, H1^b), ¹³C NMR

(CDCl₃, 100 MHz) ꢂ 61.9 (C2^c), 68.0 (C6^b), 68.2 (C6^a), 68.9

(C5^a), 69.0 (C6^c), 69.7 (C5^b), 74.0 (C4^c), 75.3 (C2^a), 75.8

(C5^c), 75.7 (C2^b), 76.0 (C4^a), 76.8 (C4^b), 77.7 (C3^a), 78.4

(C3^b), 81.2 (C3^c), 96.2 (C1^a, J_C1,H1¼ 168:5 Hz), 99.6 (C1^b,

J_C1,H1¼ 166:5 Hz), 101.7 (C1^c, J_C1,H1¼ 155:0 Hz). HRMS

(FAB) Found: m=z 1452.6338. Calcd for C₈₈H₉₁N₃NaO₁₅[M

+ Na]^þ: 1452.6348.

Condensation of 31 (40.7 mg, 0.086 mmol) and 8 (32.3 mg,

0.066 mmol) in the presence of NsCl (43.1 mg, 0.19 mmol),

AgOTf (50.0 mg, 0.19 mmol), and Et₃N (27.1 mL, 0.19 mmol)

in EtCN (0.38 mL) aﬀorded the ꢁ-linked anomer (41.4 mg,

66%) and 30 (15.3 mg, 25%) (ꢀ:ꢁ = 27:73).

Condensation of 31 (44.9 mg, 0.095 mmol) and 8 (35.6 mg,

0.073 mmol) in the presence of NsCl (46.6 mg, 0.21 mmol),

AgOTf (54.0 mg, 0.21 mmol), LiNTf₂(60.3 mg, 0.21 mmol),

and Et₃N (29.3 mL, 0.21 mmol) in CH₂Cl₂(0.41 mL) yielded

the ꢁ-linked anomer (21.8 mg, 31%) and 30 (14.6 mg, 21%)

(ꢀ:ꢁ = 40:60).

Benzyl

O-(2-Acetamido-3,4,6-tri-O-benzyl-2-deoxy-ꢀ-D-

mannopyranosyl)-(1 ! 4)-2,3,6-tri-O-benzyl-ꢁ-D-galactopyra-

nosyl-(1 ! 4)-2,3,6-tri-O-benzyl-ꢁ-D-galactopyranoside (33).

A mixture of 32 (29.1 mg, 0.020 mmol), LiAlH₄(14.0 _ꢂmg, 0.37

mmol), and anhydrous Et₂O (4.0 mL) was stirred at 40 C under

reﬂux for 0.5 h. After quenching with MeOH (4 mL) and AcOH

(0.10 mL, 1.8 mmol), Ac₂O (0.10 mL, 1.1 mmol) was added at 0

^ꢂC to the mixture. After stirring at room temperature overnight,

the mixture was evaporated and chromatographed using the TK

O-(2-Azido-3,4,6-tri-O-benzyl-2-deoxy-ꢀ-D-mannopyrano-

syl)-(1 ! 4)-2,3,6-tri-O-benzyl-^D-galactopyranose (7). A mix-

ture of 30 (44.1 mg, 0.047 mmol), PdCl₂(22.7 mg, 0.13 mmol),

NaOAc (41.1 mg, 0.50 mmol), and aq AcOH (95%, 1.76 mL)

was stirred overnight at room temperature. After addition of allyl

alcohol (17.3 mL, 0.25 mmol) at 10 ^ꢂC, the mixture was stirred for

30 min, evaporated and chromatographed with the TK system

system (100:1 ! 1:1) to give 33 (17.3 mg, 59%); ½ꢁꢄ_D+43^ꢂ

(c 0.7, CHCl₃). ¹H NMR (CDCl₃, 400 MHz) ꢂ 1.95 (3H, s,

Ac), 3.20 (dd, J_5;6a¼ 4:5 Hz, J_6a,6b¼ 8:5 Hz, H6a^b), 3.24 (br d,

H5^c), 3.40 (dd, J_5;6a¼ 4:5 Hz, J_6a,6b¼ 8:5 Hz, H6a^a), 3.40 (dd,

J_2;3¼ 4:0 Hz, J_3;4¼ 8:0 Hz, H3^c), 3.55 (dd, J_5;6a¼ 1:0 Hz,

J_6a,6b¼ 10:5 Hz, H6a^c), 3.60 (dd, J_5;6b¼ 8:5 Hz, J_6a,6b¼ 8:5

Hz, H6b^b), 3.62 (ꢅt, J_3;4¼ 8:0 Hz, J_4;5¼ 9:0 Hz, H4^c), 3.66

(dd, J_5;6b¼ 3:0 Hz, J_6a,6b¼ 10:5 Hz, H6b^c), 3.84 (ꢅt,

J_5;6b¼ 8:0 Hz, J_6a,6b¼ 8:5 Hz, H6b^a), 3.87 (dd, J_2;3¼ 10:0 Hz,

J_3;4¼ 3:0 Hz, H3^b), 3.88 (br m, H5^a), 3.88 (br d, H2^a), 3.92

(dd, J_2;3¼ 10:0 Hz, J_3;4¼ 2:0 Hz, H3^a), 3.98 (dd, J_1;2¼ 3:0

Hz, J_2;3¼ 10:0 Hz, H2^b), 4.08 (br s, H4^a), 4.32 (br s, H4^b),

4.40 (br dd, H5^b), 4.82 (s, H1^c), 4.83 (br d, J_2;NH¼ 10:0 Hz,

(100:1 ! 10:1) to give 7 (26.5 mg, 63%), ½ꢁꢄ_D+2^ꢂ(c 0.6,

CHCl₃); H NMR (CDCl₃, 300 MHz) (67%ꢁ) ꢂ 2.86 (d, J_1;OH

2:0 Hz, OH^aꢁ), 3.18 (d, J_1;OH¼ 6:5 Hz, OH^aꢀ), 3.28 (ddd, J_4;5

9:5 Hz, J_5;6a¼ 3:0 Hz, J_5;6b¼ 4:5 Hz, H5^bꢁ), 3.29 (br m, H5^bꢀ),

3.41 (dd, J_2;3¼ 3:5 Hz, J_3;4¼ 9:0 Hz, H3^bꢁ), 3.44 (dd, J_2;3¼ 3:5

Hz, J_3;4¼ 9:5 Hz, H3^bꢀ), 3.51 (dd, J_2;3¼ 9:0 Hz, J_3;4¼ 3:0 Hz,

H3^aꢀ), 3.69 (ꢅt, J_3;4¼ 9:0 Hz, J_4;5¼ 9:5 Hz, H4^bꢁ), 3.79 (dd,

J_5;6b¼ 5:5 Hz, J_6a,6b¼ 10:0 Hz, H6b^aꢁ), 3.90 (dd, J_2;3¼ 9:0

Hz, J_3;4¼ 2:5 Hz, H3^aꢁ), 3.95 (dd, J_1;2¼ 3:0 Hz, J_2;3¼ 9:0

Hz, H2^aꢁ), 4.02 (dd, J_1;2¼ 1:5 Hz, J_2;3¼ 3:5 Hz, H2^bꢁ), 4.04

(dd, J_1;2¼ 1:5 Hz, J_2;3¼ 3:5 Hz, H2^bꢀ), 4.15 (dd, J_3;4¼ 3:0

Hz, J_4;5¼ 1:0 Hz, H4^aꢀ), 4.19 (dd, J_3;4¼ 2:5 Hz, J_4;5¼ 1:5

Hz, H4^aꢁ), 4.20 (ꢅt, J_4;5¼ 1:5 Hz, J_5;6a¼ J_5;6b¼ 1:5 Hz,

H5^aꢁ), 4.66 (dd, J_1;2¼ 7:5 Hz, J_1;OH¼ 6:5 Hz, H1^aꢀ), 4.70 (d,

J_1;2¼ 1:5 Hz, H1^bꢀ), 4.71 (d, J_1;2¼ 1:5 Hz, H1^bꢁ), 5.30 (ꢅt,

J_1;2¼ 3:0 Hz, J_1;OH¼ 2:0 Hz, H1^aꢁ); ¹³C NMR (CDCl₃, 75

NH), 4.87 (br d, H2^c), 4.92 (d, J_1;2¼ 3:0 Hz, H1^a), 4.98 (d, J_1;2

3:0 Hz, H1^b); ¹³C NMR (CDCl₃, 100 MHz) ꢂ 23.4 (Ac), 50.1 (br,

C2^c), 67.9 (C6^b), 68.2 (C6^a), 68.7 (C6^c), 69.0 (C5^b), 69.8 (C5^a),

74.0 (C4^c), 74.1 (C4^b), 75.2 (C5^c), 75.5 (C2^a), 75.9 (C4^a), 77.0

(C2^b), 77.9 (C3^a), 78.9 (C3^b), 81.2 (C3^c), 96.0 (C1^a,

J_C1,H1¼ 168:0 Hz), 99.9 (C1^b, J_C1,H1¼ 167:0 Hz), 100.0 (C1^c,

1614 Bull. Chem. Soc. Jpn., 76, No. 8 (2003)

Synthesis of ꢀ-Mannoside and ꢀ-Mannosaminide

J_C1,H1¼ 158:0 Hz), 171.1 (br) (Ac); HRMS (FAB) Found: m=z

1468.6554. Calcd for C₉₀H₉₅NNaO₁₆[M + Na]^þ: 1468.6549.

O-(2-Acetamido-2-deoxy-ꢀ-D-mannopyranosyl)-(1 ! 4)-O-

ꢁ-D-galactopyranosyl-(1 ! 4)-D-galactopyranose (3). Hydro-

genation of 33 (27.9 mg, 0.019 mmol) over Pd on C (10%, 36

mg) in AcOH (6 mL) at room temperature overnight, ﬁltration

of the catalyst, concentration, and chromatography with the EM

Na₂SO₄for 30 min, ﬁltered, and evaporated, to give a monotriﬂate

as a syrup (1.324 g). This was dissolved in DMF (3.75 mL) and

treated with n-BuNN₃(5.0 g, 18 mmol) at room temperature over-

night and then at 40 ^ꢂC for 4 h. Work-up and chromatography

with the TK system (100:1 ! 3:1) yielded allyl 2-azido-4,6-O-

benzylidene-2-deoxy-ꢁ-D-mannopyranoside (0.620 g, 38%); mp

141–142 ^ꢂC, ½ꢁꢄ_D+79^ꢂ(c 1.0, CHCl₃); ¹H NMR (CDCl₃,

system (100:1 ! 2:1) aﬀorded 3 (8.2 mg, 78%); ½ꢁꢄ_D+67^ꢂ

300 MHz)

ꢂ

2.66 (d, J_3;OH¼ 3:5 Hz, OH), 3.91 (t,

(c 0.3, H₂O); ¹H NMR (D₂O, 400 MHz) (ꢅ40%ꢁ) ꢂ 2.03 (3H,

s, Ac), 3.36 (ddd, J_4;5¼ 10:0 Hz, J_5;6a¼ 5:5 Hz, J_5;6b¼ 2:0 Hz,

H5^c), 3.47 (ꢅt, J_3;4¼ 9:5 Hz, J_4;5¼ 10:0 Hz, H4^c), 3.48 (dd,

J_1;2¼ 8:0 Hz, J_2;3¼ 10:0 Hz, H2^aꢀ), 3.59 (dd, J_5;6a¼ 6:0 Hz,

J_6a,6b¼ 11:5 Hz, H6a^b), 3.60 (dd, J_5;6a¼ 6:0 Hz, J_6a,6b¼ 11:5

Hz, H6a^aꢀ), 3.68 (dd, J_2;3¼ 10:0 Hz, J_3;4¼ 3:0 Hz, H3^aꢀ),

3.73 (dd, J_1;2¼ 3:5 Hz, J_2;3¼ 10:0 Hz, H2^bꢁ), 3.74 (dd,

J_1;2¼ 3:5 Hz, J_2;3¼ 10:0 Hz, H2^bꢀ), 3.75 (dd, J_5;6b¼ 6:5 Hz,

J_6a,6b¼ 11:5 Hz, H6b^aꢀ and H6b^b), 3.77 (dd, J_5;6a¼ 5:5 Hz,

J_6a,6b¼ 12:0 Hz, H6a^c), 3.78 (dd, J_2;3¼ 4:5 Hz, J_3;4¼ 9:5 Hz,

H3^c), 3.81 (dd, J_1;2¼ 3:5 Hz, J_2;3¼ 10:5 Hz, H2^aꢁ), 3.88 (dd,

J_5;6b¼ 2:0 Hz, J_6a,6b¼ 12:0 Hz, H6b^c), 3.89 (dd, J_2;3¼ 10:5

Hz, J_3;4¼ 3:0 Hz, H3^aꢁ), 3.94 (dd, J_2;3¼ 10:0 Hz, J_3;4¼ 3:0

Hz, H3^bꢁ), 3.95 (dd, J_3;4¼ 3:0 Hz, J_4;5¼ 1:5 Hz, H4^aꢀ), 3.96

(dd, J_2;3¼ 10:0 Hz, J_3;4¼ 3:0 Hz, H3^bꢀ), 4.01 (dd, J_3;4¼ 3:0

J_3;4¼ J_4;5¼ 9:5 Hz, H4), 4.00 (dd, J_1;2¼ 1:5 Hz, J_2;3¼ 3:5

Hz, H2), 4.30 (dt, J_2;3¼ J_3;OH¼ 3:5 Hz, J_3;4¼ 9:5 Hz, H3),

4.84 (d, J_1;2¼ 1:5 Hz, H1), 5.58 (s, benzylidene), 5.90 (m, All);

¹³C NMR (CDCl₃, 75 MHz) ꢂ 63.5 (C5), 63.7 (C2), 68.4 (All),

68.6 (C6), 68.9 (C3), 80.0 (C4), 98.1 (C1, J_C1,H1¼ 170:6 Hz),

102.2 (benzylidene, J_C,H¼ 162:0 Hz), 118.1, 133.1 (All). Found:

C, 57.87; H, 5.76; N, 12.38%. Calcd for C₁₆H₁₉N₃O₅: C, 57.65; H,

5.75; N, 12.61%. A mixture of this azido acetal (1.6246 g, 4.9

ꢂ

mmol) and aq AcOH (80%, 16 mL) was heated at 95 C for 15

min with stirring. Evaporation and chromatography with the

CM system (100:1 ! 2:1) aﬀorded allyl 2-azido-2-deoxy-ꢁ-D-

mannopyranoside (0.9513 g); ½ꢁꢄ_D+127^ꢂ(c 1.1, MeOH)

(Ref. 13, ½ꢁꢄ_D+108.7^ꢂ(c 0.8, MeOH)). HRMS (FAB) Found:

m=z 268.0913. Calcd for C₉H₁₅N₃NaO₅[M + Na]^þ: 268.0909.

This (398.6 mg, 1.6 mmol) was reacted with BnBr (1.2 mL, 10

mmol) and NaH (ca. 60% in oil, 393.6 mg, 9.8 mmol) in DMF

(4.0 mL) at 0 ^ꢂC for 15 min then 20 ^ꢂC for 60 min. After quench-

Hz, J_4;5¼ 1:0 Hz, H4^aꢁ), 4.10 (ꢅt, J_4;5¼ 1:0 Hz, J_5;6a¼ J_5;6b

6:0 Hz, H5^aꢁ), 4.18 (dd, J_3;4¼ 3:0 Hz, J_4;5¼ 1:0 Hz, H4^bꢁ), 4.19

(dd, J_3;4¼ 3:0 Hz, J_4;5¼ 1:0 Hz, H4^bꢀ), 4.33 (ꢅt, J_4;5¼ 1:5 Hz,

J_5;6a¼ 6:0 Hz, J_5;6b¼ 6:5 Hz, H5^aꢀ), 4.35 (ꢅt, J_4;5¼ 1:0 Hz,

J_5;6a¼ J_5;6b¼ 6:0 Hz, H5^b), 4.58 (dd, J_1;2¼ 1:0 Hz, J_2;3¼ 3:0

Hz, H2^c), 4.60 (d, J_1;2¼ 8:0 Hz, H1ꢀ^a), 4.86 (d, J_1;2¼ 3:5 Hz,

H1^bꢀ), 4.88 (d, J_1;2¼ 3:0 Hz, H1^bꢁ), 4.89 (d, J_1;2¼ 1:0 Hz,

H1^c), 5.26 (d, J_1;2¼ 3:5 Hz, H1ꢁ^a); ¹³C NMR (D₂O, 100 MHz)

ꢂ 24.6 (Ac), 55.9 (C2^c), 62.8 (C6^aꢀ and C6^b), 63.0 (C6^aꢁ),

63.1 (C6^c), 69.6 (C4^c), 71.1 (C2^aꢁ), 71.4 (C3^aꢁ), 71.8 (C3^b),

72.8 (C5^b), 72.9 (C5^aꢀ), 73.5 (C5^aꢁ), 74.5 (C2^aꢀ and C3^c),

75.0 (C3^aꢀ), 77.7 (C2^b), 78.7 (C5^c), 79.0 (C4^b), 79.9 (C4^aꢀ),

81.2 (C4^aꢁ), 95.0 (C1^aꢁ, J_C1,H1¼ 168:0 Hz), 99.3 (C1ꢀ^a,

J_C1,H1¼ 160:0 Hz), 102.7 (C1^c, J_C1,H1¼ 158:0 Hz), 102.8

(C1^bꢀ, J_C1,H1¼ 170:0 Hz), 103.0 (C1^bꢁ, J_C1,H1¼ 168:0 Hz),

178.3 (Ac). HRMS (FAB) Found: m=z 568.1868. Calcd for

C₂₀H₃₅NNaO₁₆[M + Na]^þ: 568.1854.

ꢂ

ing with MeOH (10 mL), evaporation at 90 C and chromatogra-

phy with the TK system (100:1 ! 20:1) yielded a syrup (681.2

mg). This (244.4 mg, 0.47 mmol) was stirred in aq AcOH

(95%, 18 mL) containing PdCl₂(117.4 mg, 0.66 mmol) and

NaOAc (216.1 mg, 2.6 mmol) at room temperature overnight_ꢂ.¹³

After quenching with allyl alcohol (0.5 mL, 7.4 mmol) at 10 C

for 20 min, evaporation and chromatography with the TK system

(100:1 ! 20:1) gave 31 (149.0 mg, 43%), which was identiﬁed

with the sample prepared before.^7a

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