From polymer to size-defined oligomers: A highly divergent and stereocontrolled construction of chondroitin sulfate A, C, D, E, K, L, and M oligomers from a single precursor: Part 2

FULL PAPER

DOI: 10.1002/chem.200900741

From Polymer to Size-Defined Oligomers: A Highly Divergent and

Stereocontrolled Construction of Chondroitin Sulfate A, C, D, E, K, L, and M

Oligomers from a Single Precursor: Part 2**

Jean-Claude Jacquinet,* Chrystel Lopin-Bon, and Aude Vibert^[a]

Abstract: An efficient, stereocon-

trolled, and highly divergent approach

for the preparation of oligomers of

chondroitin sulfate (CS) A, C, D, E, K,

L, and M variants, starting from a

single precursor easily obtained by

semisynthesis from abundant natural

polymer is reported for the first time.

Common intermediates were designed

that allowed the straightforward con-

struction of O-sulfonated species either

on the d-galactosamine unit (CS-A, -C,

and -E) or on both d-glucuronic acid

and d-galactosamine units (CS-D and

CS-K, -L, and -M). This strategy repre-

sents a successful improvement and

brings a definitive answer toward the

synthesis of such complex molecules

with numerous relevant biological

functions.

Keywords: carbohydrates

droitin sulfate glycosylation

oligosaccharides · sulfo forms

· chon-

·

Introduction

lating evidences implies CS chains in cytokinesis, cell prolif-

eration, migration and differentiation, tissue morphogenesis,

and infection.^[2]CS chains interact with a large variety of

structures such as growth factors, cytokines, and adhesion

molecules through specific saccharide domains within the

chains.^[3,4]

Chondroitin sulfate (CS) belongs to a family of linear, mi-

croheterogeneous, polyanionic complex polysaccharides

called glycosaminoglycans (GAGs). They are distributed as

side chains of proteoglycans (PGs) in the extracellular

matrix

es or at the cell surface of animal tissues. They are co-

Unfortunately, structurally defined oligosaccharide frag-

ments of CS are not easily prepared, even though they are

in great demand according to their potential therapeutic ap-

plications. Because of the heterogeneity of the polymer and

since no regularly O-sulfonated species are found in nature,

natural sources seldom provide sufficient amounts of com-

plex oligomers for further evaluation of their full biological

potential. Accordingly, for deciphering the CS code,^[5]effi-

cient synthetic methodologies are required for producing

enough pure material for biological studies. Several chemi-

cal syntheses of various CS oligosaccharides have been re-

ported in the last decade, most of them starting from mono-

meric units.^[6]A combinatorial approach was used for the

preparation of a library of variously O-sulfonated disaccha-

polymers made up of dimeric units composed of d-glucuron-

ic acid (d-GlcA) and 2-acetamido-2-deoxy-d-galactose (d-

GalNac) and contain, on average, one sulfate group per di-

ACHTUNGTRENNUNGsaccharide unit, but several variants, also called sulfo forms,

with sulfate(s) at various positions are known.^[1]Although

heparin, another member of the GAG family, has been ex-

tensively studied and has an established position in therapy

today, CS attracted less attention until the turn of the mil-

lennium when its sulfation pattern, also called sulfo code,

was found to give rise to numerous relevant biological func-

tions. In addition to its conventional structural role, accumu-

[a] Dr. J.-C. Jacquinet, Dr. C. Lopin-Bon, A. Vibert

Institut de Chimie Organique et Analytique

UMR 6005 Universitꢀ d’Orlꢀans et CNRS

Universitꢀ d’Orlꢀans, BP 6759

AHCTUNGTRENNUNG

rides,^[7]and an enzymatic synthesis of the 4-sulfate variant

(CS-A) through polymerization of a 4-sulfated disaccharide

oxazoline derivative catalyzed by hyaluronidase has been re-

ported.^[8]However, no efficient general method allowing the

preparation of size-defined oligomers for all known CS var-

iants is still available.

We recently disclosed the possible chemical synthesis of

size-defined chondroitin oligomers by semisynthesis starting

from easily available CS polymer.^[9]This step economy pro-

45067 Orlꢀans Cedex (France)

Fax : (+33)2-3841-7281

E-mail: Jean-Claude.Jacquinet@univ-orleans.fr

[**] For Part 1, see: A. Vibert, C. Lopin-Bon, J.-C. Jacquinet, Chem. Eur.

J. 2009, DOI: 10.1002/chem.200900740.

Supporting information for this article is available on the WWW

under http://dx.doi.org/10.1002/chem.200900741.

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cess allowed the efficient construction of size-defined oligo-

mers up to octasaccharides as reducing species or biotinylat-

ed conjugates.^[10]Herein, we further report the development

of this strategy for an expeditious and stereocontrolled con-

struction of size-defined oligomers of all known CS variants

from a single precursor.

dure.^[13]Benzoate esters were found to be suitable for per-

manent protection of hydroxy groups that were not to be O-

sulfonated. Accordingly, conventional benzoylation of diol 1

gave the crystalline 2’,3’-dibenzoate 2, which should be able

to be used as a unique precursor for the preparation of CS-

A, -C, and -E variants. Regioselective 3’-benzoylation of 1

with benzoyl cyanide cleanly afforded the crystalline 3’-ben-

zoate 3, potential precursor of the CS-D variant, whereas

tin-mediated^[14]selective benzoylation gave predominantly

the crystalline 2’-benzoate 4 in 68% yield, precursor of CS-

K, -L, and -M variants. Having in hand these three tailor-

made building blocks, easily available on a multigram scale,

we first focused on the preparation of O-sulfonated variants

on the d-GalNAc unit.

Results and Discussion

Structurally speaking, CS variants can be divided into two

main classes: those bearing sulfate group(s) on the d-

GalNAc unit (4-sulfated CS-A, 6-sulfated CS-C, and 4,6-di-

ACHTUNGTRENNUNGsulfated CS-E) or on both d-GlcA and d-GalNAc moieties

(6,2’-disulfated CS-D, 4,3’-disulfated CS-K, 6,3’-disulfated

CS-L, and 6,4,3’-trisulfated CS-M). To achieve the prepara-

tion of all these possible sulfo forms (and others that should

be discovered in the near future), the disaccharide building

block 1 (Scheme 1), easily prepared in 11 steps from the

Syntheses of CS-A, -C, and -E oligomers: In an attempt

to try to reduce the number of chemical transformations,

common precursors to the A, C, and E oligomers were de-

signed (Scheme 2). To this end, the benzylidene acetal in 2

was first hydrolyzed and the intermediate diol was chloroa-

cetylated to give the crystalline

ester 5. The necessity of remov-

ing the 4,6-acetal before further

activation at the anomeric

center to avoid extensive for-

mation of unwanted 1,2-cis-gly-

coside in glycosylation reaction

is still being discussed.^[15]The

ester 5 was either transformed

into acceptor 6 through selec-

tive delevulinoylation with hy-

drazine acetate, or into donor 7

through oxidative removal of

the NAP group with 2,3-di-

chloro-5,6-dicyanobenzoqui-

none (DDQ) followed by tri-

chloroacetimidoylation. A cou-

pling reaction of alcohol 6 with

imidate 7 under the catalysis of

trimethylsilyl triflate (TMSOTf)

afforded the tetrasaccharide de-

rivative 8 in 71% as a single

Scheme 1. The versatility of diol 1 toward the preparation of chondroitin sulfate (CS) A, C, D, E, K, L, and M

variants. a) PhCOCl, CH₂Cl₂/pyridine, 08C, 1 h, 91%; b) PhCOCN, pyridine, 6 h, 80%; c) Bu₂SnO, dioxane/

benzene, reflux, 7 h; then PhCOCl (1 equiv), RT, 16 h, 68% overall. TCA=trichloroacetyl, NAP=2-naphthyl-

methyl, Lev=4-oxopentanoate, Bz=benzoyl.

stereoisomer. Selective delevu-

linoylation of 8 gave the crystal-

line alcohol 9, which, upon fur-

ther coupling with imidate 7

under similar conditions, gave

abundant natural polymer (see Part 1^[10]), was selected as a

versatile starting material. Its protective group pattern al-

lowed either elongation at the reducing end by oxidative re-

moval^[11]of the 2-naphthylmethyl (NAP) group followed by

imidoylation, or at the nonreducing end through selective

removal of the levulinoyl (Lev) group, as previously report-

ed.^[9]The 2-deoxy-2-trichloroacetamido group in 1 was used

since it proved to be a powerful stereocontrolling auxiliary

for the preparation of 1,2-trans-2-amino-2-deoxyglyco-

sides,^[12]and the crucial coupling reactions were planned

using Schmidtꢂs trichloroacetimidate glycosylation proce-

the crystalline hexasaccharide derivative 10 in 68% yield.

This latter should be able to be used after selective delevu-

ACHUTNGRENlNUG inACHUTNGTRENoNGUN ylation as an acceptor for further elongation at the non-

reducing end. Selective removal of the chloroacetate esters

in 8 and 10 with thiourea gave the crystalline tetrol and

hexaol intermediates, respectively, the N-trichloroacetyl

groups of which were subjected to radical reduction with tri-

n-butylstannane^[12]to afford the crystalline key intermedi-

ates 11 and 12, respectively, in good yields.

The transformation of 11 and 12 into the corresponding

CS-A, C, and E variants was then achieved as follows

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Stereocontrolled Construction of Size-Defined Oligomers

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Scheme 2. Construction of the precursors of CS-A, -C, and -E variants. a) 75% AcOH, 1008C, 30 min; then (ClAc)₂O, CH₂Cl₂/pyridine, 08C, 1 h, 83 %

overall; b) hydrazine acetate, pyridine, 2 min, 89% for 6, 82% for 9; c) DDQ, CH₂Cl₂/MeOH, 24 h; then Cl₃CCN, DBU, CH₂Cl₂, 30 min, 61% overall;

d) TMSOTf, CH₂Cl₂, 45 min, 71%; e) 7, TMSOTf, CH₂Cl₂, 45 min, 68%; f) thiourea, pyridine/EtOH, 808C, 2 h; then Bu₃SnH, AIBN, benzene/DMAC,

808C, 4 h, 77% overall for 11, 69% for 12. DDQ=2,3-dichloro-5,6-dicyanobenzoquinone, DBU=1,8-diazabicyclo

ACHTUNGTRNE[NUNG 5.4.0]undec-7-ene, ClAc=mono-

ACHTUNGTRENNUNGchloroacetyl, TMSOTf=trimethylsilyl trifluoromethanesulfonate, AIBN=2,2’-azobis-2-methylpropionitrile, DMAC=N,N-dimethylacetamide.

(Scheme 3). Selective benzoylation at O-6 of 11 and 12 with

benzoyl cyanide gave the crystalline 6-benzoylated deriva-

tives, respectively, which were further treated with an excess

of sulfur trioxide/trimethylamine complex in N,N-dimethyl-

formamide (DMF) at 608C to provide, after ion exchange

with a [Na⁺] resin, the 4-sulfated derivatives 13 and 14, re-

spectively, in 72 and 85% overall yields. Comparison of the

¹H NMR spectra of 13 and 14 and those of their precursors,

recorded in the same mixture of solvents (CD₃OD/CDCl₃

3:1), showed the expected^[16]downfield shifts (d=0.8–

1.0 ppm) of the signals for GalNAc H-4 in 13 and 14. Con-

trolled regioselective 6-O-sulfonation of 11 and 13 at 408C

followed by acetylation and ion exchange gave the 6-sulfat-

ed derivatives 15 and 16, respectively, in 83 and 81% yields.

Though the downfield shifts for GalNAc H-6a,b in the

¹H NMR spectra of 15 and 16 was smaller (d=0.2–0.3 ppm)

than those observed for GalNAc H-4 in 4-sulfated species,

the presence of telling signals at d=5.50–5.20 ppm, charac-

teristic of H-4 protons in 4-O-acetylated-d-galacto deriva-

tives, ensured exclusive O-sulfonation at C-6. Exhaustive O-

sulfonation of 11 and 12 provided the 4,6-disulfated deriva-

tives 17 and 18, respectively, in 86 and 82% yields, the

¹H NMR spectra of which showed the expected downfield

shifts for GalNAc H-4 and H-6a,b. Deprotection of sulfo

forms 13–18 was then achieved through a two-step saponifi-

cation process, avoiding a b-elimination reaction at the d-

GlcA units with lithium hydroperoxide^[17]and sodium hy-

droxide, to afford the target glycosides 19–24 in more than

1

80% yield. The H and ¹³C NMR spectra for 19–24 showed

high purity and were fully consistent with the expected

structures. These molecules, fitted out with a fluorophore

(NAP group), should be very useful as probes for the study

of the sulfotransferases involved in the biosynthesis of these

CS variants. Catalytic hydrogenation of 19–24 with 10% pal-

ladium on carbon in water afforded the target-reducing olig-

omers 25–30 in excellent yields. Despite the presence of

severe chemical shift overlap due to a,b-reducing mixture,

1

the H and ¹³C NMR spectra for 25–30 showed high purity.

It was the first time that these reducing oligomers were syn-

thesized and fully characterized.

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Scheme 3. Access to chondroitin sulfate A, C, and E tetra- and hexasaccharides. a) PhCOCN, pyridine, 6 h; then Me₃N·SO₃(5 equiv), DMF, 608C, 48 h;

then SP-C25 [Na⁺] resin, 72% overall for 13, 85% for 14; b) Me₃N·SO₃(2 equiv), DMF, 408C, 2 h 30; then Ac₂O/pyridine, 16 h; then SP-C25 [Na⁺]

resin, 83% overall for 15, 81% for 16; c) Me₃N·SO₃(5 equiv), DMF, 608C, 48 h; then SP-C25 [Na⁺] resin, 86% overall for 17, 82% for 18; d) LiOH/

H₂O₂, THF/H₂O, 0 8C!RT, 16 h; then 4m NaOH, MeOH, 10 h, 81–84% for 19–24; e) H₂, Pd/C, H₂O, 24 h, 88–95% for 25–30. DMF=N,N-dimethyl-

ACHTUNGTRENNUNGformamide, THF=tetrahydrofuran.

mild acid hydrolysis afforded the crystalline diol 31, which

was further subjected to selective chloroacetylation at O-6

with chloroacetic anhydride at ꢀ208C followed by benzoyl-

Synthesis of CS-D oligomers: The CS-D (6,2’-disulfated)

motif was isolated from shark cartilage^[18]and was found to

play an important role in brain development.^[19]With alco-

hol 3 in hand, the synthesis of CS-D oligomers was next un-

dertaken (Scheme 4). Chloroacetylation of 3 followed by

AHCTUNGTREGaNNNU tion at O-4 to give the disaccharide derivative 32 in good

yield. The ester 32 was either transformed into donor 33 or

acceptor 34 following the same protocol as reported. A cou-

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Stereocontrolled Construction of Size-Defined Oligomers

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catalytic hydrogenation provide

the known^[6f]reducing disac-

charide 42 and the reducing tet-

rasaccharide 43 in high yield.

This expeditious route com-

pares well, in term of length

and efficiency, with those previ-

ously reported by our group

starting from d-glucose and d-

glucosamine.^[6d,f]

Synthesis of CS-K, -L, and -M

oligomers: These less common

sulfo forms were identified in

marine animals (king crab,

squid, skate). Their intriguing

and not yet fully understood

biological functions in the cen-

tral nervous system^[1]prompted

us to find an efficient route for

the preparation of these var-

iants. First of all, the synthesis

of the basic reducing disacchar-

ides

was

undertaken

(Scheme 5). To this end, the al-

cohol 4 was subjected to radical

reduction of its N-tri

ACHTUNGTRENNUNGchloACHTUNGTRENNUNGro-

AHCTUNGTRENNUNG

acidic hydrolysis to give the

crystalline triol derivative 44 in

good yield. This key intermedi-

ate was used as a single precur-

sor for the preparation of the

three sulfo forms CS-K, -L, and

-M. Selective benzoylation at

O-6 followed by O-sulfonation

at C-4 and C-3’, as reported,

gave the 4,3’-disulfated deriva-

tive 45 in 80% overall yield.

Comparison of the ¹H NMR

spectra of 45 and 44 showed the

Scheme 4. Access to chondroitin sulfate D di- and tetrasaccharides. a) (ClAc)₂O, CH₂Cl₂/pyridine, 08C, 1 h;

then 80% AcOH, 808C, 30 min, 83% overall; b) (ClAc)₂O, CH₂Cl₂/pyridine, ꢀ208C, 20 min; then PhCOCl,

CH₂Cl₂/pyridine, 08C, 1 h, 76% overall; c) DDQ, CH₂Cl₂/MeOH, 24 h; then Cl₃CCN, DBU, CH₂Cl₂, 30 min,

66% overall; d) hydrazine acetate, pyridine, 2 min, 82%; e) TMSOTf, CH₂Cl₂, 1 h, 68%; f) Thiourea, pyridine/

EtOH, 808C, 2 h; then Bu₃SnH, AIBN, benzene/DMAC, 808C, 4 h, 73% overall for 36, 82% for 37;

g) Me₃N·SO₃(5 equiv), DMF, 608C, 48 h; then SP-C25 [Na⁺] resin, 90% for 38, 88% for 39; h) LiOH/H₂O₂,

THF/H₂O, 0 8C!RT, 16 h; then 4m NaOH, MeOH, 10 h, 90% for 40, 81% for 41; i) H₂, Pd/C, H₂O, 24 h,

92% for 42, 90% for 43.

pling reaction of imidate 33 with alcohol 34 under the catal-

ysis of TMSOTf gave the tetrasaccharide derivative 35 in

68% yield. Selective removal of the chloroacetate esters on

32 and 35 followed by radical reduction of their N-trichloro-

relevant downfield shifts of the signals of GalNAc H-4 (d

ꢁ0.9 ppm) and GlcA H-3 (dꢁ1.1 ppm) in 45, in full agree-

ment with those reported for oligosaccharide fragments iso-

lated from king crab cartilage.^[21]Interestingly, carefully con-

trolled selective O-sulfonation of 44 afforded the 6,3’-disul-

fate 46 as a major product in 75% yield, along with approxi-

mately 10% of its trisulfated congener 47, thus showing that

in a sulfation reaction of this triol, the relative reactivity of

the hydroxy groups clearly followed the order O-6>O-3’>

O-4. Exhaustive O-sulfonation of 44 gave the trisulfate 47 in

ACHTUNGTRENNUNGacetyl groups as described provided the acetamides 36 and

37. Exhaustive O-sulfonation of 36 and 37 gave the 6,2’-dis-

ulfated species 38 and 39 in 90 and 88% yields, respectively.

1

Comparison of the H NMR spectra of 38 and 39 and those

of their respective precursors showed a significant downfield

shift (dꢁ0.9 ppm) for the signal of GlcA H-2 as well as

those (dꢁ0.4 ppm) for the signals of GalNAc H-6a,b in sul-

fates 38 and 39. These values are in full agreement with

those reported for oligosaccharide fragments isolated by hy-

aluronidase degradation of shark cartilage CS-D.^[20]Saponi-

fication of 38 and 39 as reported gave the target glycosides

40 and 41, respectively, in 90 and 81% yields, which upon

1

90% yield, the H NMR spectra of which showed the ex-

pected characteristic downfield shifts of the signals for pro-

tons on carbon bearing a sulfate group. Final transformation

of 45–47 was achieved through saponification and catalytic

hydrogenation as described to provide the target-reducing

sulfo forms 51–53. Noticeable in these later variants is the

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Scheme 5. Access to chondroitin sulfate K, L, and M disaccharides. a) Bu₃SnH, AIBN, benzene/DMAC, 808C, 4 h; then 80% AcOH, 808C, 30 min, 80%

overall; b) PhCOCN, pyridine, 6 h; then Me₃N·SO₃(5 equiv), DMF, 608C, 48 h; then SP-C25 [Na⁺] resin, 80% overall; c) Me₃N·SO₃(3 equiv), DMF,

408C, 24 h, then SP-C25 [Na⁺] resin, 75%; d) Me₃N·SO₃(5 equiv), DMF, 608C, 48 h; then SP-C25 [Na⁺] resin, 90%; e) LiOH/H₂O₂, THF/H₂O, 0 8C!

RT, 16 h; then 4m NaOH, MeOH, 10 h, 86–88% for 48–50; f) H₂, Pd/C, H₂O, 24 h, 94–95% for 51–53.

relevant downfield shift (dꢁ10 ppm) observed in their

¹³C NMR spectra for the C-3’ signal in 48–50 and 51–53

compared to their non-3’-O-sulfonated congeners.

55 and 56 gave the intermediates 57 and 58, respectively,

which were readily transformed into acceptors 59 and 61 or

donors 60 and 62 respectively, as reported. Coupling reac-

tion of 59 with 60 and 61 with 62 provided the tetrasacchar-

ide derivatives 63 and 64, respectively, in 65 and 62% yields.

The ¹H NMR spectra of these latter compounds showed that

no acyl migration of the acid-sensitive 3’-chloroacetate oc-

curred in these coupling reactions. Following a similar se-

quence as those reported above, the tetrasaccharide deriva-

tives 63 and 64 were transformed into the corresponding

acetamides 65 and 66, respectively, which upon O-sulfona-

tion and saponification gave the glycosides 69 and 70, re-

spectively. The ¹H and ¹³C NMR spectra of 69 and 70

showed the same characteristic features as those reported

for their disaccharide congeners 48 and 49. Catalytic hydro-

genation of 69 and 70 allowed the obtention for the first

time of reducing tetrasaccharides 71 and 72, respectively.

The construction of CS-K and -L tetrasaccharides was

then achieved as follows (Scheme 6). Chloroacetylation of

alcohol 4 followed by mild acid hydrolysis gave the crystal-

line key intermediate 54. However, for the preparation of

this latter compound, a tin-free procedure could be achieved

starting from alcohol 1. Selective chloroacetylation of diol 1

with N-chloroacetyl imidazole gave the crystalline inter-

mediate 3’-chloroacetate, which upon benzoylation followed

by acid hydrolysis afforded the expected diol 54 in 60%

overall yield. Starting from this common intermediate, a

short route to gain access to precursors of CS-K and -L was

designed. Treatment of diol 54 with trimethyl orthobenzoate

in the presence of a catalytic amount of 10-camphorsulfonic

acid (CSA) gave the intermediate 4,6-orthoester, which was

treated with aqueous acetic acid to give the 6-O-benzoyl

(54) and the 4-O-benzoyl (55) derivatives in a ratio of ap-

proximately 1:1 and in excellent yield. This means that

under mildly acidic conditions, the oxygen atoms at C-4 and

C-6 in the transient orthoester were equally protonated and

that no other factors, steric or electronic, influenced the ste-

reochemical outcome of the hydrolysis. Chloroacetylation of

Conclusion

An efficient and highly divergent approach for the construc-

tion of oligomers of chondroitin sulfate (CS) A, C, D, E, K,

L, and M variants from a single precursor is described for

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Stereocontrolled Construction of Size-Defined Oligomers

FULL PAPER

copy. The crystallinity of most

intermediates as well as the ex-

cellent stereoselectivity and the

good yields achieved in glycosy-

lation reaction using a moder-

ate excess of glycosyl donors

brings a definitive answer to

the problem of the synthesis of

such complex molecules. In ad-

dition, the strategy employed

here can be extended for the

preparation of larger oligomers.

We do hope that this collection

of molecules, which are in great

demand, will help to decipher

the intriguing biological func-

tions of these natural products.

Experimental Section

General methods: Solvents were dried

by standard methods, and molecular

sieves were activated prior to use by

heating for 4 h at 5008C. Melting

points were determined in capillary

tubes using a Bꢃchi apparatus and are

uncorrected. Optical rotations were

measured at 20–258C using a Perkin–

Elmer 341 polarimeter. ¹H and

¹³C NMR spectra were recorded at

258C using Bruker DPX 250 and Ad-

vance II 400 instruments, with Me₄Si

as internal standard, unless otherwise

stated. Assignments were based on

homo- and heteronuclear correlations

using the supplierꢂs software. In the

NMR data for oligomers, GlcA^Iand

GalN^I(with roman numeral super-

scripts) refer to d-glucuronic acid and

d-galactosamine residues, respectively,

in the reducing disaccharide unit.

Low-resolution mass spectra were ob-

tained using a Perkin–Elmer SCIEX

API 300 spectrometer operating in the

ion-spray mode or using a Micromass

Quattro

Ultima

spectrometer

equipped with

a

Z-spray ionization

Scheme 6. Access to chondroitin sulfate K and L tetrasaccharides. a) (ClAc)₂O, CH₂Cl₂/pyridine, 08C, 1 h;

then 80% AcOH, 808C, 30 min, 82% overall; b) N-chloroacetylimidazole, 1,2-dichloroethane, 508C, 30 min;

then PhCOCl, CH₂Cl₂/pyridine, 08C, 1 h; then 80% AcOH, 808C, 30 min, 60% overall; c) PhCHACTHNURGTNEUNG(OMe)₃,

source operating in the negative mode.

HRMS were obtained from the Centre

Regional de Mesure Physique (Uni-

versitꢀ Blaise Pascal, Clermont-Fer-

rand, France). Flash silica chromatog-

raphy was performed on silica gel 60

(0.040–0.063 mm, Merck, Darmstadt).

The reactions were monitored by TLC

on coated aluminum sheets (silica gel

60 GF₂₅₄, Merck), and spots were de-

tected under UV light and by charring

with a 95:5 mixture of ethanol and sul-

furic acid. Elemental analyses were

carried out at the Service Central de Microanalyse du CNRS (Vernaison,

France).

CSA, toluene/CH₂Cl₂, 45 min; then 80% AcOH, RT, 15 min, 47% for 55 and 43% for 56; d) (ClAc)₂O,

CH₂Cl₂/pyridine, 08C, 1 h, 92% for 57, 93% for 58; e) hydrazine acetate, pyridine, 2 min, 87% for 59, 80%

for 61; f) DDQ, CH₂Cl₂/MeOH, 24 h; then Cl₃CCN, DBU, CH₂Cl₂, 30 min, 67% overall for 60, 68% for 62;

g) TMSOTf, CH₂Cl₂, 45 min, 65% for 63, 62% for 64; h) thiourea, pyridine/EtOH, 808C, 2 h; then Bu₃SnH,

AIBN, benzene/DMAC, 808C, 4 h, 69% overall for 65 and 66; i) Me₃N·SO₃(5 equiv), DMF, 608C, 48 h; then

SP-C25 [Na⁺] resin, 90% for 67, 89% for 68; j) LiOH/H₂O₂, THF/H₂O, 0 8C!RT, 16 h; then 4m NaOH,

MeOH, 10 h, 88% for 69, 90% for 70; k)) H₂, Pd/C, H₂O, 24 h, 93% for 71, 92% for 72. CSA=camphorsul-

fonic acid.

the first time. This procedure allowed the preparation of

reasonable amounts of chemically pure substances, which

1

were fully characterized through H and ¹³C NMR spectros-

Chem. Eur. J. 2009, 15, 9579 – 9595

ꢁ 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

www.chemeurj.org

9585

J.-C. Jacquinet et al.

2-Naphthylmethyl O-(methyl 2,3-di-O-benzoyl-4-O-levulinoyl-b-d-gluco-

pyranosyluronate)-(1!3)-4,6-O-benzylidene-2-deoxy-2-trichloroacetami-

do-b-d-galactopyranoside (2): Benzoyl chloride (1.08 mL, 9 mmol) was

added at 08C to a solution of 2-naphthylmethyl O-(methyl 4-O-levulino-

yl-b-d-glucopyranosyluronate)-(1!3)-4,6-O-benzylidene-2-deoxy-2-tri-

chloroacetamido-b-d-galactopyranoside (1; 2.52 g, 3 mmol) in anhydrous

pyridine (10 mL) and CH₂Cl₂(16 mL), and the mixture was stirred for

1 h at 08C. The reaction was then quenched with MeOH (1 mL), diluted

with CH₂Cl₂(100 mL), washed with water, saturated aqueous NaHCO₃

and water, dried (MgSO₄), and concentrated. The solid residue was re-

crystallized from hot MeOH to give the disaccharide 2 (2.86 g, 91%).

R_f=0.40 (CH₂Cl₂/acetone 16:1); m.p. 231–2328C; [a]²_D²=+30 (c=1 in

chloroform); ¹H NMR (250 MHz, CDCl₃): d=7.92–7.30 (m, 22H; arom.

H), 6.99 (d, J_2,NH=6.5 Hz, 1H; GalN NH), 5.62 (dd, J_2,3=J_3,4=9.0 Hz,

1H; GlcA H-3), 5.59 (s, 1H; CHPh), 5.48 (m, 2H; GlcA H-2,H-4), 5.22

(d, J_1,2=8.0 Hz, 1H; GalN H-1), 5.18 (d, J_1,2=7.5 Hz; GlcA H-1), 4.92

(ABq, 2H; CH₂Ar), 4.75 (dd, J_2,3=11.0 Hz, J_3,4=3.5 Hz; GalN H-3), 4.49

(dd, J_4,5<1 Hz; GalN H-4), 4.39 (dd, J_5,6a=1.5 Hz, J_6a,6b=12.0 Hz; GalN

H-6a), 4.19 (d, J_4,5=10.0 Hz; GlcA H-5), 4.12 (dd, J_5,6b=2.0 Hz; GalN H-

6b), 3.84 (m, 1H; GalN H-2), 3.75 (s, 3H; COOCH₃), 3.55 (m, 1H; GalN

H-5), 2.82–2.55 (m, 4H; CH₂CO), 2.06 ppm (s, 3H; COCH₃); MS: m/z:

1070 [M+Na]⁺(for ³⁵Cl); elemental analysis calcd (%) for

C₅₂H₄₈Cl₃NO₁₆: C 59.58, H 4.52, N 1.34; found: C 59.50, H 4.45, N 1.27.

AcOH/water (3/1, 32 mL) was stirred at 1008C for 30 min. The clear so-

lution was then cooled, concentrated, evaporated with water (3ꢄ10 mL),

and the solid residue was recrystallized from hot EtOH to give the inter-

mediate diol (1.21 g, 91%): R_f=0.40 (CH₂Cl₂/MeOH 15:1); m.p. 201–

2028C. Freshly recrystallized chloroacetic anhydride (0.86 g, 5 mmol) was

added at 08C to a solution of the diol in anhydrous CH₂Cl₂(15 mL) and

pyridine (5 mL), and the mixture was stirred for 1 h at 08C. Crushed ice

was then added, and the mixture was diluted with CH₂Cl₂(80 mL),

washed with water, saturated aqueous NaHCO₃and water, dried

(MgSO₄) and concentrated. Flash silica chromatography (CH₂Cl₂/acetone

15:1) gave the ester 5 (1.28 g, 83% from 2). M.p. 165–1668C; [a]²_D²=+26

(c=1 in chloroform); ¹H NMR (250 MHz, CDCl₃): d=7.80–7.30 (m,

17H; arom. H), 6.75 (d, J_2,NH=7.0 Hz, 1H; GalN NH), 5.60 (dd, J_3,4

=

3.5 Hz, J_4,5<1.0 Hz, 1H; GalN H-4), 5.59 (dd, J_2,3=J_3,4=9.5 Hz, 1H;

GlcA H-3), 5.44 (dd, J_4,5=9.5 Hz, 1H; GlcA H-4), 5.33 (dd, J_1,2=7.5 Hz,

1H; GlcA H-2), 5.08 (d, J_1,2=8.5 Hz, 1H; GalN H-1), 4.86 (ABq, 2H;

CH₂Ar), 4.85 (d, 1H; GlcA H-1), 4.80 (dd, J_2,3=11.0 Hz, 1H; GalN H-3),

4.33 (m, 2H; GalN H-6a, H-6b), 4.24 (ABq, 2H; COCH₂Cl), 4.12 (s, 2H;

COCH₂Cl), 4.01 (m, 1H; GalN H-5), 3.80 (s, 3H; COOCH₃), 2.72–2.30

(m, 4H; CH₂CO), 2.03 ppm (s, 3H; COCH₃); MS: m/z: 1134 [M+Na]⁺

(for ³⁵Cl); elemental analysis calcd (%) for C₄₉H₄₅Cl₅NO₁₈: C 52.82, H

4.16, N 1.26; found: C 52.80, H 4.09, N 1.20.

2-Naphthylmethyl O-(methyl 2,3-di-O-benzoyl-b-d-glucopyranosyluro-

nate)-(1!3)-4,6-di-O-chloroacetyl-2-deoxy-2-trichloroacetamido-b-d-gal-

actopyranoside (6): A freshly prepared mixture of pyridine/AcOH/hydra-

zine hydrate (6:4:0.5, 10.5 mL) was added to a solution of 5 (0.60 g,

0.54 mmol) in pyridine (2 mL), and the mixture was stirred for 2 min,

then was diluted with CH₂Cl₂(50 mL), washed with cold water, saturated

aqueous NaHCO₃and water, dried (MgSO₄), and concentrated. Flash

silica chromatography (CH₂Cl₂/acetone 15:1) gave the alcohol 6 (0.49 g,

89%). M.p. 193–1948C; [a]²_D²=+20 (c=1 in chloroform); ¹H NMR

2-Naphthylmethyl O-(methyl 3-O-benzoyl-4-O-levulinoyl-b-d-glucopyra-

nosyluronate)-(1!3)-4,6-O-benzylidene-2-deoxy-2-trichloroacetamido-b-

d-galactopyranoside (3): A mixture of 1 (420 mg, 0.5 mmol) and benzoyl

cyanide (165 mg, 1.25 mmol) in anhydrous pyridine (8 mL) was stirred

for 6 h at RT. Methanol (0.5 mL) was added, and the mixture was con-

centrated. Flash silica chromatography (CH₂Cl₂/acetone 11:1) and crystal-

lization of the residue from EtOH gave the 3’-benzoate 3 (380 mg, 80%).

M.p. 203–2048C; [a]²_D²=+12 (c=1 in chloroform); ¹H NMR (250 MHz,

CDCl₃): d=7.90–7.30 (m, 17H; arom. H), 7.22 (d, J=7.0 Hz, 1H; GalN

NH), 5.58 (s, 1H; CHPh), 5.31 (dd, J_2,3=J_3,4=9.0 Hz, 1H; GlcA H-3),

5.28 (dd, J_4,5=10.0 Hz, 1H; GlcA H-4), 5.16 (d, J_1,2=8.0 Hz, 1H; GalN

H-1), 4.93 (ABq, 2H; CH₂Ar), 4.68 (d, J_1,2=7.5 Hz, 1H; GlcA H-1), 4.59

(dd, J_2,3=11.0 Hz, J_3,4=3.5 Hz, 1H; GalN H-3), 4.40 (m, 2H; GalN H-4,

H-6a), 4.08 (m, 2H; GalN H-6b, GlcA H-5), 3.96 (m, 1H; GalN H-2),

3.73 (m, 1H; GlcA H-2), 3.72 (s, 3H; COOCH₃), 3.50 (m, 1H; GalN H-

5), 2.98 (d, J=3.5 Hz, 1H; GlcA HO-2), 2.80–2.48 (m, 4H; CH₂CO),

2.01 ppm (s, 3H; COCH₃); MS: m/z: 966 [M+Na]⁺(for ³⁵Cl); elemental

analysis calcd (%) for C₄₅H₄₃Cl₃NO₁₅: C 57.24, H 4.59, N 1.48; found: C

57.12, H 4.63, N 1.40.

(400 MHz, CDCl₃): d=7.90–7.30 (m, 17H; arom. H), 6.74 (d, J_2,NH

=

7.0 Hz, 1H; GalN NH), 5.60 (dd, J_3,4=3.5 Hz, J_4,5<1.0 Hz, 1H; GalN H-

4), 5.47 (dd, J_2,3=J_3,4=9.5 Hz, 1H; GlcA H-3), 5.28 (dd, J_1,2=7.5 Hz, 1H;

GlcA H-2), 5.10 (d,

J_1,2=8.5 Hz, 1H; GalN H-1), 4.85 (ABq, 2H;

CH₂Ar), 4.83 (d, 1H; GlcA H-1), 4.82 (dd, J_2,3=11.0 Hz, 1H; GalN H-3),

4.32 (m, 2H; GalN H-6a, H-6b), 4.24 (ABq, 2H; COCH₂Cl), 4.15 (m,

J

_4,OH=3.0 Hz; GlcA H-4), 4.12 (s, 2H; COCH₂Cl), 4.01 (m, 2H; GalN H-

5, GlcA H-5), 3.87 (s, 3H; COOCH₃), 3.51 (m, 1H; GalN H-2), 3.28 ppm

(d, 1H; GlcA HO-4); MS: m/z: 1039 [M+Na]⁺(for ³⁵Cl); elemental

analysis calcd (%) for C₄₄H₄₀Cl₅NO₁₆: C 52.01, H 3.97, N 1.38; found: C

51.90, H 4.05, N 1.27.

2-Naphthylmethyl O-(methyl 2-O-benzoyl-4-O-levulinoyl-b-d-glucopyra-

nosyluronate)-(1!3)-4,6-O-benzylidene-2-deoxy-2-trichloroacetamido-b-

O-(Methyl 2,3-di-O-benzoyl-4-O-levulinoyl-b-d-glucopyranosyluronate)-

(1!3)-4,6-di-O-chloroacetyl-2-deoxy-2-trichloroacetamido-1-O-trichlor-

oacetimidoyl-a-d-galactopyranose (7): A mixture of 5 (4.10 g, 3.68 mmol)

and DDQ (2.5 g, 11 mmol) in CH₂Cl₂/MeOH (9:1, 50 mL) was stirred for

24 h, then was diluted with CH₂Cl₂(100 mL), washed with water, saturat-

ed aqueous NaHCO₃and water, dried (MgSO₄), and concentrated. Flash

silica chromatography (CH₂Cl₂/acetone 9:1) gave the hemiacetal (2,97 g,

83%) as a pale yellow foam. A solution of the hemiacetal, trichloroace-

tonitrile (2.5 mL, 25 mmol), and DBU (80 mL, 0.52 mmol) in CH₂Cl₂

(20 mL) was stirred for 30 min, then was concentrated. Flash silica chro-

matography (EtOAc/petroleum ether 1:1 containing 0.2% of Et₃N) gave

the imidate 7 (2.39 g, 61% from 5) as a colorless foam. [a]²_D²=+99 (c=1

in chloroform); ¹H NMR (250 MHz, CDCl₃): d=8.78 (s, 1H; C=NH),

7.90–7.30 (m, 10H; arom. H), 6.75 (d, J_2,NH=8.0 Hz, 1H; GalN NH), 6.53

(d, J_1,2=3.5 Hz, 1H; GalN H-1), 5.69 (dd, J_3,4=3.5 Hz, J_4,5<1.0 Hz, 1H;

d-gaACHTUNGTRENNUNGlactoACHTUNGTRENNUNGpyranoside (4): A mixture of 1 (337 mg, 0.4 mmol) and di-n-bu-

tyltin oxide (110 mg, 0.44 mmol) in 1,4-dioxane (15 mL) and benzene

(15 mL) was stirred at reflux with continuous removal of water (Dean–

Stark apparatus) for 7 h. Solvents (18 mL) were then slowly distilled at

atmospheric pressure, and the mixture was cooled to RT under argon.

Benzoyl chloride (48 mL, 0.4 mmol) was added, and the mixture was

stirred overnight, then was concentrated. Flash silica chromatography

(CH₂Cl₂/acetone 11:1) gave first the 3’-benzoate 3 (61 mg, 16%). Next

eluted was the 2’-benzoate 4 (257 mg, 68%). M.p. 211–2128C (from

EtOH); [a]²_D²=+2 (c=1 in chloroform); ¹H NMR (250 MHz, CDCl₃):

d=8.10–7.20 (m, 17H; arom. H), 7.07 (d, J=7.0 Hz, 1H; GalN NH),

5.55 (s, 1H; CHPh), 5.24 (dd, J_1,2=7.0 Hz, J_2,3=9.0 Hz, 1H; GlcA H-2),

5.21 (dd, J_3,4=9.0 Hz, J_4,5=10.0 Hz, 1H; GlcA H-4), 5.16 (d, J_1,2=8.0 Hz,

1H; GalN H-1), 5.07 (d, 1H; GlcA H-1), 4.91 (ABq, 2H; CH₂Ar), 4.70

(dd, J_2,3=11.0 Hz, J_3,4=3.5 Hz, 1H; GalN H-3), 4.48 (dd, J_4,5=1.0 Hz,

1H; GalN H-4), 4.25 (m, 2H; GalN H-6a, H-6b), 4.05 (d, 1H; GlcA H-

5), 3.88 (m, 1H; GalN H-2), 3.87 (m, 1H; GlcA H-3), 3.72 (s, 3H;

COOCH₃), 3.52 (m, 1H; GalN H-5), 3.16 (d, J=6.0 Hz, 1H; GlcA HO-

3), 2.81–2.39 (m, 4H; CH₂CO), 2.10 ppm (s, 3H; COCH₃); MS: m/z: 966

[M+Na]⁺(for ³⁵Cl); elemental analysis calcd (%) for C₄₅H₄₃Cl₃NO₁₅: C

57.24, H 4.59, N 1.48; found: C 57.18, H 4.67, N 1.39.

GalN H-4), 5.64 (dd, J_2,3=J_3,4=9.5 Hz, 1H; GlcA H-3), 5.42 (dd, J_4,5

9.5 Hz, 1H; GlcA H-4), 5.38 (dd, J_1,2=7.5 Hz, 1H; GlcA H-2), 5.07 (d,

_1,2=7.5 Hz, 1H; GlcA H-1), 4.62 (m, J_2,3=11.0 Hz, 1H; GalN H-2),

=

J

4.45–4.33 (m, 3H; GalN H-3, H-6a, H-6b), 4.18 (ABq, 2H; COCH₂Cl),

4.16 (m, 1H; GalN H-5), 4.06 (s, 2H; COCH₂Cl), 3.80 (s, 3H;

COOCH₃), 2.72–2.35 (m, 4H; CH₂CO), 2.04 ppm (s, 3H; COCH₃); MS:

m/z: 1137 [M+Na]⁺(for ³⁵Cl); elemental analysis calcd (%) for

C₄₀H₃₈Cl₈N₂O₁₈: C 42.96, H 3.43, N 2.50; found: C 42.77, H 3.49, N 2.31.

2-Naphthylmethyl O-(methyl 2,3-di-O-benzoyl-4-O-levulinoyl-b-d-gluco-

pyranosyluronate)-(1!3)-4,6-di-O-chloroacetyl-2-deoxy-2-trichloroaceta-

mido-b-d-galactopyranoside (5): A suspension of 2 (1.46 g, 1.39 mmol) in

Tetrasaccharide 8: A mixture of imidate 7 (1.096 g, 0.98 mmol), alcohol 6

(712 mg, 0.7 mmol), and activated powdered 4 ꢅ molecular sieves (0.5 g)

in anhydrous CH₂Cl₂(16 mL) was stirred for 1 h at RT under dry argon.

9586

www.chemeurj.org

ꢁ 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Chem. Eur. J. 2009, 15, 9579 – 9595

Stereocontrolled Construction of Size-Defined Oligomers

FULL PAPER

A solution of TMSOTf in toluene (1m, 185 mL) was added, and the mix-

ture was stirred for 45 min. Triethylamine (0.28 mL) was added, and the

mixture was filtered and concentrated. Flash silica chromatography (tolu-

ene/EtOAc 4:3, containing 0.1% of NEt₃) gave the tetrasaccharide 8

(0.98 g, 71%) as a colorless foam. [a]²_D²=+18 (c=1 in chloroform);

¹H NMR (400 MHz, C₆D₆): d=8.05–6.95 (m, 27H; arom. H), 6.37, 6.34

(2d, J_2,NH=7.5 Hz, 2H; 2GalN NH), 5.88 (dd, J_2,3=J_3,4=9.5 Hz, 1H;

troleum ether (20 mL). The solids were filtered off, washed with petrole-

um ether, and recrystallized from hot EtOH to give the acetamide 11

(337 mg, 77% from 8). M.p. 215–2178C; [a]²_D²=+22 (c=1 in chloro-

form); ¹H NMR (400 MHz, CD₃OD/CDCl₃3:1): d=8.0–7.10 (m, 27H;

arom. H), 5.71 (dd, J_2,3=J_3,4=9.5 Hz, 1H; GlcA^IIH-3), 5.53 (dd, J_2,3

=

J

_3,4=9.5 Hz, 1H; GlcA^IH-3), 5.48 (dd, J_1,2=7.5 Hz, 1H; GlcA^IIH-2),

5.36 (dd, J_4,5=9.5 Hz, 1H; GlcA^IIH-4), 5.28 (dd, J_1,2=7.5 Hz, 1H; GlcA^I

H-2), 4.96, 4.95 (2d, 2H; 2GlcA H-1), 4.86 (ABq, 2H; CH₂Ar), 4.76, 4.68

(2d, J_1,2=8.0 Hz; 2GalN H-1), 4.36 (dd, J_4,5=9.5 Hz, 1H; GlcA^IH-4),

4.27(d, 1H; GlcA^IIH-5), 4.26 (dd, J_2,3=11.0 Hz, J_3,4=3.5 Hz, 1H; GalN

H-3), 4.20 (d, 1H; GlcA^IH-5), 4.15 (dd, J_2,3=11.0 Hz, J_3,4=3.5 Hz, 1H;

GalN H-3), 4.06, 3.98 (2dd, J_4,5<1 Hz, 2H; 2GalN H-4), 3.90–3.80 (m,

4H; 4GalN H-6), 3.75, 3.69 (2s, 6H; COOCH₃), 3.70–3.65 (2m, 2H;

2GalN H-5), 3.35 (m, 2H; 2GalN H-2), 2.70–2.25 (m, 4H; CH₂CO), 2.03

(s, 3H; COCH₃), 1.26, 1.24 ppm (2s, 6H; NHCOCH₃); MS: m/z: 1459.5

[M]^ꢀ; elemental analysis calcd (%) for C₇₄H₇₈N₂O₂₉: C 60.90, H 5.39, N

1.92; found: C 60.72, H 5.43, N 1.81.

GlcA^IIH-3), 5.84 (dd, J_2,3=J_3,4=9.5 Hz, 1H; GlcA^IH-3), 5.66 (dd, J_1,2

7.5 Hz, 1H; GlcA^IIH-2), 5.64 (dd, J_4,5=9.5 Hz, 1H; GlcA^IIH-4), 5.61

(dd, J_1,2=7.5 Hz, 1H; GlcA^IH-2), 5.47, 5.34 (2dd, J_3,4=3.5 Hz, J_4,5

=

<

1 Hz, 2H; 2GalN H-4), 5.08, 4.87 (2d, J_1,2=8.0 Hz, 2H; 2GalN H-1), 4.74

(d, 1H; GlcA^IIH-1), 4.72 (ABq, 2H; CH₂Ar), 4.69 (d, 1H; GlcA^IH-1),

4.58, 4.41 (2dd, J_2,3=11.0 Hz, 2H; 2GalN H-3), 4.52 (dd, 1H; GlcA^IH-

4), 4.25–4.12 (m, 4H; 2GalN H-6a, H-6b), 4.00 (d, 1H; GlcA^IIH-5), 3.94

(d, 1H; GlcA^IH-5), 3.80, 3.66 (2s, 6H; COOCH₃), 3.75–3.50 (m, 8H;

COCH₂Cl), 3.50 (m, 2H; 2GalN H-2), 3.28 (m, 2H; 2GalN H-5), 2.40–

1.80 (m, 4H; CH₂CO), 1.48 ppm (s, 3H; COCH₃); MS: m/z: 1985

[M+NH₄]⁺(for ³⁵Cl); elemental analysis calcd (%) for C₈₂H₇₆Cl₁₀N₂O₃₃

:

Hexasaccharide acetamide 12: From hexasaccharide 10 (637 mg,

0.22 mmol) as described for the preparation of 11. Flash silica chromatog-

raphy (CH₂Cl₂/MeOH 15:1) gave the intermediate hexaol (454 mg,

85%): m.p. 176–1788C (from EtOH); MS: m/z: 2389 [M+Na]⁺(for

³⁵Cl). The hexaol (450 mg, 0.19 mmol) was treated as described for the

preparation of 11. Flash silica chromatography (CH₂Cl₂/MeOH 9:1) gave

the acetamide 12 (312 mg, 69% from 10). M.p. 236–2388C (from

MeOH); [a]²_D²=+14 (c=1 in methanol); ¹H NMR (400 MHz, CD₃OD/

CDCl₃3:1): d=8.0–7.30 (m, 37H; arom. H), 5.72 (dd, J_2,3=J_3,4=9.5 Hz,

1H; GlcA^IIIH-3), 5.55, 553 (2dd, J_2,3=J_3,4=9.5 Hz, 2H; GlcA^IH-3,

C 49.94, H 3.88, N 1.42; found: C 50.02, H 3.75, N 1.31.

Tetrasaccharide acceptor 9: From 8 (915 mg, 0.46 mmol) as described for

the preparation of 6. Flash silica chromatography (EtOAc/petroleum

ether 4:3) gave the alcohol 9 (713 mg, 82%). M.p. 141–1428C (from 2-

propanol); [a]²_D²=+11 (c=1 in chloroform); ¹H NMR (400 MHz,

CDCl₃): d=8.0–7.30 (m, 27H; arom. H), 6.73, 6.64 (2d, J_2,NH=7.5 Hz,

2H; 2GalN NH), 5.50, 5.37 (2dd, J_3,4=3.5 Hz, J_4,5<1 Hz, 2H; 2GalN H-

4), 5.44 (dd, J_2,3=J_3,4=9.5 Hz, 1H; GlcA^IH-3), 5.42 (dd, J_2,3=J_3,4

=

9.5 Hz, 1H; GlcA^IIH-3), 5.25 (dd, J_1,2=7.5 Hz, 1H; GlcA^IH-2), 5.18

(dd, J_1,2=7.5 Hz, 1H; GlcA^IIH-2), 5.07 (d, J_1,2=8.0 Hz, 2H; 2GalN H-1),

4.77 (d, 1H; GlcA^IH-1), 4.85 (ABq, 2H; CH₂Ar), 4.75 (d, 1H; GlcA^II

H-1), 4.72, 4.63 (2dd, J_2,3=11.0 Hz, 2H; 2GalN H-3), 4.35 (m, 2H;

2GlcA H-4), 4.20–4.0 (m, 12H; 2GalN H-5, 2GalN H-6, COCH₂Cl), 4.0,

3.96 (2d, 2H; 2GlcA H-5), 3.84, 3.82 (2s, 6H; COOCH₃), 3.50 (m, 3H;

2GalN H-6, GalN H-2), 3.28 (m, 1H; GalN H-2), 3.27 ppm (d, J=3.0 Hz,

1H; GlcA^IIHO-4); MS: m/z: 1893 [M+Na]⁺(for ³⁵Cl); elemental analy-

sis calcd (%) for C₇₇H₇₀Cl₁₀N₂O₃₁: C 49.35, H 3.76, N 1.49; found: C

49.12, H 3.80, N 1.33.

GlcA^IIH-3), 5.40 (dd, J_1,2=7.5 Hz, 1H; GlcA^IIIH-2), 5.37 (dd, J_4,5

=

9.5 Hz, 1H; GlcA^IIIH-4), 5.28, 5.27 (2dd, J_1,2=7.5 Hz, 2H; GlcA^IH-2,

GlcA^IIH-2), 4.99, 4.98, 4.97 (3dd, 3H; 3GlcA H-1), 4.85 (ABq, 2H;

CH₂Ar), 4.71, 4.58, 4.54 (3d, J_1,2=8.0 Hz; 3GalN H-1), 4.35, 4.34 (2dd,

J

_4,5=9.5 Hz, 2H; GlcA^IH-4, GlcA^IIH-4), 4.29 (d, 1H; GlcA^IIIH-5),

4.21, 4.18 (2d, 2H; GlcA^IH-5, GlcA^IIH-5), 4.16 (m, 2H; 2GalN H-3),

4.08, 3.99, 3.92 (3dd, J_3,4=3.5 Hz, J_4,5<1 Hz, 3H; 3GalN H-4), 3.90–3.75

(m, 7H; GalN H-3, 6GalN H-6), 3.76, 3.70, 3.67 (3s, 9H; COOCH₃),

3.60–3.50 (m, 3H; 3GalN H-5), 3.30–3.25 (m, 3H; 3GalN H-2), 2.72–2.28

(m, 4H; CH₂CO), 2.02 (s, 3H; COCH₃), 1.30, 1.26, 1.24 ppm (3s, 9H;

NHCOCH₃); MS: m/z: 2054.9 [M]^ꢀ; elemental analysis calcd (%) for

C₁₀₃H₁₀₉N₃O₄₂: C 60.02, H 5.33, N 2.04; found: C 59.87, H 5.21, N 1.81.

Hexasaccharide 10: From alcohol 9 (521 mg, 0.28 mmol) and imidate 7

(559 mg, 0.5 mmol) as described for the preparation of 8. Flash silica

chromatography (EtOAc/petroleum ether 4:3, containing 0.1% of NEt₃)

gave the hexasaccharide 10 (533 mg, 68%) as a white foam. M.p. 146–

1478C (from 2-propanol); [a]²_D²=+12 (c=1 in chloroform); ¹H NMR

(400 MHz, CDCl₃): d=8.0–7.30 (m, 37H; arom. H), 6.70, 6.64, 6.62 (3d,

CS-A disulfate 13: From tetrol 11 (255 mg, 175 mmol) as described for

the preparation of 3. Flash silica chromatography (CH₂Cl₂/MeOH 19:1)

gave the intermediate diol (255 mg, 87%) as a white solid. M.p. 230–

1

2328C (from MeOH); H NMR (400 MHz, CD₃OD/CDCl₃3:1): d=8.05–

J

_2,NH=7.5 Hz, 3H; 3GalN NH), 5.55, 5.44, 5.37 (3dd, J_2,3=J_3,4=9.5 Hz,

7.25 (m, 37H; arom. H), 5.74 (dd, J_2,3=J_3,4=9.5 Hz, 1H; GlcA^IIH-3),

5.58 (dd, J_2,3=J_3,4=9.5 Hz, 1H; GlcA^IH-3), 5.42 (dd, J_1,2=7.5 Hz, 1H;

3H; 3GlcA H-3), 5.50, 5.34, 5.26 (3dd, J_3,4=3.5 Hz, J_4,5<1 Hz, 3H;

3GalN H-4), 5.42, 5.22, 5.15 (3dd, J_1,2=7.5 Hz, 3H; 3GlcA H-2), 5.25

(dd, J_4,5=9.5 Hz, 1H; GlcA^IIIH-4), 5.06, 5.05, 5.01 (3d, J_1,2=8.0 Hz;

3GalN H-1),), 4.86 (ABq, 2H; CH₂Ar), 4.77, 4.76, 4.71 (3d, 3H; 3GlcA

H-1), 4.75, 4.57, 4.54 (3dd, J_2,3=11.0 Hz; 3GalN H-3), 4.32, 4.28 (2dd,

2H; GlcA^IH-4, GlcA^IIH-4), 4.25–4.0 (m, 12H; COCH₂Cl), 3.96, 3.93,

3.91 (3d, 3H; 3GlcA H-5), 381, 3.79, 3.77 (3s, 9H; COOCH₃), 3.80–3.70

(m, 6H; 3GalN H-5, 3GalN H-6), 3.58, 3.42 (2m, 3H; 3GalN H-6), 3.50,

3.25 (2m, 3H; 3GalN H-2), 2.60–2.25 (m, 4H; CH₂CO), 2.03 ppm (s, 3H;

COCH₃); elemental analysis calcd (%) for C₁₁₅H₁₀₆Cl₁₅N₃O₄₈: C 48.81 H

3.77, N 1.48; found: C 48.70, H 3.69, N 1.40.

GlcA^IIH-2), 5.37 (dd, J_4,5=9.5 Hz, 1H; GlcA^IIH-4), 5.33 (dd, J_1,2

=

7.5 Hz, 2H; GlcA^IH-2), 5.01 (d, 1H; GlcA^IIH-1), 4.98 (d, 1H; GlcA^IH-

1), 4.84 (ABq, 2H; CH₂Ar), 4.74, 4.63 (2d, J_1,2=8.0 Hz; 2GalN H-1),

4.61 (m, 2H; 2GalN H-6), 4.34 (dd, J_4,5=9.5 Hz, 1H; GlcA^IH-4), 4.32,

4.18 (2d, 2H; GlcA^IH-5, GlcA^IIH-5), 4.25, 4.08 (2dd, J_2,3=11.0 Hz,

J

_3,4=3.5 Hz, 2H; 2GalN H-3), 4.14, 4.04 (2dd, J_4,5<1 Hz, 2H; 2GalN H-

4), 3.90–378 (m, 4H; 2GalN H-5, 2GalN H-6), 3.67, 3.64 (2s, 6H;

COOCH₃), 3.50 (m, 2H; 2GalN H-2), 2.72–2.30 (m, 4H; CH₂CO), 2.04

(s, 3H; COCH₃), 1.30, 1.28 ppm (2s, 6H; NHCOCH₃). A mixture of the

diol (250 mg, 150 mmol) and sulfur trioxide/trimethylamine complex

(210 mg, 1.5 mmol) in anhydrous DMF (3 mL) was stirred for 24 h at

608C, then was cooled. Methanol (0.5 mL) was added, and the mixture

was directly eluted from a column (4ꢄ60 cm) of Sephadex LH-20 with

1:1 CH₂Cl₂/MeOH. Fractions containing the product were next eluted

from a column (1.5ꢄ30 cm) of Sephadex SP C-25 [Na⁺] with 9:5:1

CH₂Cl₂/MeOH/water to give the disulfate 13 (234 mg, 72% from 11) as a

white powder. R_f=0.40 (CH₂Cl₂/MeOH 6:1); [a]²_D²=+44 (c=1 in metha-

nol); ¹H NMR (400 MHz, CD₃OD/CDCl₃3:1): d=8.10–7.15 (m, 37H;

Tetrasaccharide acetamide 11: A mixture of 8 (590 mg, 0.3 mmol) and

thiourea (190 mg, 2.5 mmol) in pyridine–EtOH (1:1, 10 mL) was stirred

for 2 h at 808C, then was cooled and concentrated. A solution of the resi-

due in CH₂Cl₂(50 mL) was washed with water, saturated aqueous

NaHCO₃and water, dried (MgSO₄), and concentrated. Flash silica chro-

matography (CH₂Cl₂/MeOH 14:1) gave the intermediate tetrol (450 mg,

90%). M.p. 242–2448C (from EtOH); MS: m/z: 1686 [M+Na]⁺(for

³⁵Cl). Argon was bubbled for 1 h at RT through a solution of the tetrol

(448 mg, 0.27 mmol), tri-n-butylstannane (0.84 mL, 3 mmol), and AIBN

(100 mg) in benzene-N,N-dimethylacetamide (1:1, 8 mL), and the mixture

was then stirred for 2 h at 808C. More tri-n-butylstannane (0.28 mL,

1 mmol) and AIBN (50 mg) in N,N-dimethylacetamide (0.5 mL) were

then added, and stirring was resumed for 2 h at 808C. The mixture was

then cooled and concentrated, and the residue was stirred at 08C with pe-

arom. H), 5.92 (dd, J_2,3=J_3,4=9.5 Hz, 1H; GlcA^IIH-3), 5.68 (dd, J_2,3

J

=

_3,4=9.5 Hz, 1H; GlcA^IH-3), 5.52 (dd, J_4,5=9.5 Hz, 1H; GlcA^IIH-4),

5.51 (dd, J_1,2=7.5 Hz, 1H; GlcA^IIH-2), 5.43 (dd, J_1,2=7.5 Hz, 1H; GlcA^I

H-2), 5.27, 4.99 (2dd, J_3,4=3.5 Hz, J_4,5<1 Hz, 2H; 2GalN H-4), 5.15, 5.14

(2d, 2H; 2GlcA H-1), 4.94, 4.85 (2d, J_1,2=8.0 Hz; 2GalN H-1), 4.84

(ABq, 2H; CH₂Ar), 4.75 (m, 2H; 2GalN H-6), 4.41 (d, 1H; GlcA^IIH-5),

Chem. Eur. J. 2009, 15, 9579 – 9595

ꢁ 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

www.chemeurj.org

9587

J.-C. Jacquinet et al.

4.28 (d, 1H; GlcA^IH-5), 4.25 (dd, 1H; GlcA^IH-4), 4.18 (m, 2H; 2GalN

H-3), 4.10–3.90 (m, 6H; 2GalN H-5, 4GalN H-6), 3.67, 3.58 (2s, 6H;

COOCH₃), 3.38 (m, 2H; GalN H-2), 2.70–2.32 (m, 4H; CH₂CO), 2.02 (s,

3H; COCH₃), 1.38, 1.28 ppm (2s, 6H; NHCOCH₃); HRMS: m/z: calcd

for [C₈₈H₈₄N₂Na₂O₃₇S₂ꢀ2Na+2H]^2ꢀ: 912.2097; found: 912.2085.

4.40–4.30 (m, 4H; 2GalN H-3, GlcA^IH-4, GlcA^IIH-4), 4.29, 4.26, 4.24

(3d, 3H; 3GlcA H-5), 4.10–3.95 (m, 6H; 3GalN H-5, 3GalN H-6), 3.84,

3.81, 3.78 (3s, 9H; COOCH₃), 3.63–3.54 (m, 4H; GalN H-2, 3GalN H-6),

3.30 (m, 2H; 2GalN H-2), 2.70–2.35 (m, 4H; CH₂CO), 2.03 (s, 3H;

COCH₃), 2.01, 1.80, 1.78 (3s, 9H; OCOCH₃), 1.32, 1.29, 1.26 ppm (3s,

9H;

NHCOCH₃);

HRMS:

m/z:

calcd

for

CS-A trisulfate 14: From hexaol 12 (288 mg, 140 mmol) as described for

the preparation of 3. Flash silica chromatography (CH₂Cl₂/MeOH 15:1)

gave the intermediate triol (283 mg, 85%) as a white solid. M.p. 242–

[C₁₀₉H₁₀₉N₃Na₃O₅₄S₃ꢀ3Na+3H]^3ꢀ: 807.5091; found: 807.5089.

CS-E tetrasulfate 17: From tetrol 11 (255 mg, 175 mmol) as described for

the O-sulfonation of 13 to give the tetrasulfate 17 (281 mg, 86%) as a

white powder. R_f=0.40 (EtOAc/MeOH/water 5:2:1); [a]²_D²=+27 (c=1

in methanol); ¹H NMR (400 MHz, CD₃OD/CDCl₃3:1): d=8.0–7.23 (m,

27H; arom. H), 5.76 (dd, J_2,3=J_3,4=9.5 Hz, 1H; GlcA^IIH-3), 5.63 (dd,

1

2448C (from MeOH); H NMR (400 MHz, CD₃OD/CDCl₃3:1): d=8.05–

7.25 (m, 52H; arom. H), 5.73 (dd, J_2,3=J_3,4=9.5 Hz, 1H; GlcA^IIIH-3),

5.58 (dd, J_2,3=J_3,4=9.5 Hz, 1H; GlcA^IIH-3), 5.56 (dd, J_2,3=J_3,4=9.5 Hz,

1H; GlcA^IH-3), 5.41 (dd, J_1,2=7.5 Hz, 1H; GlcA^IIIH-2), 5.36 (dd, J_4,5

=

J

_2,3=J_3,4=9.5 Hz, 1H; GlcA^IH-3), 5.47 (dd, J_4,5=9.5 Hz, 1H; GlcA^IIH-

4), 5.45 (dd, J_1,2=7.5 Hz, 1H; GlcA^IIH-2), 5.39 (dd, J_1,2=7.5 Hz, 1H;

GlcA^IH-2), 5.05 (d, 1H; GlcA^IIH-1), 5.0, 4.94 (2dd, J_3,4=3.5 Hz, J_4,5

9.5 Hz, 1H; GlcA^IIIH-4), 5.34 (dd, J_1,2=7.5 Hz, 1H; GlcA^IIH-2), 5.30

(dd, J_1,2=7.5 Hz, 1H; GlcA^IH-2), 5.0, 4.98, 4.97 (3d, 3H; 3GlcA H-1),

4.85 (ABq, 2H; CH₂Ar), 4.72, 4.64, 4.62 (3d, J_1,2=8.0 Hz; 3GalN H-1),

4.60–4.54 (m, 3H; GalN H-6), 4.32, 4.31 (2dd, J_4,5=9.5 Hz, 2H; GlcA^I

<

1 Hz, 2H; 2GalN H-4), 4.96 (d, 1H; GlcA^IH-1), 4.84 (ABq, 2H;

CH₂Ar), 4.58 (dd, 1H; GlcA^IH-4), 4.54 (d, 1H; GlcA^IH-5), 4.44–4.36

(m, 4H; 2GalN H-1, 2GalN H-3), 4.34 (d, 1H; GlcA^IIH-5), 4.05, 3.98

(2dd, J_2,3=11.0 Hz, 2H; 2GalN H-2), 3.96–3.78 (m, 6H; 2GalN H-5,

4GalN H-6), 3.83, 3.77 (2s, 6H; COOCH₃), 2.68–2.32 (m, 4H; CH₂CO),

2.01 (s, 3H; COCH₃), 1.32, 128 ppm (2s, 6H; NHCOCH₃); HRMS: m/z:

calcd for [C₇₄H₇₄N₂Na₄O₄₁S₄ꢀ4Na+4H]^4ꢀ: 443.5662; found: 443.5678.

H-4, GlcA^IIH-4), 4.30, 4.28, 4.26 (3d, 3H; 3GlcA H-5), 4.23 (dd, J_2,3

=

11.0 Hz, J_3,4=3.5 Hz, 1H; GalN H-3), 4.14, 4.04, 3.94 (3dd, J_4,5<1 Hz,

3H; 3GalN H-4), 4.08 (m, 2H; 2GalN H-3), 3.85–3.70 (m, 6H; 3GalN H-

5, 3GalN H-6), 3.67, 3.61, 3.55 (3s, 9H; COOCH₃), 3.63, 3.56, 3.48 (3dd,

3H; 3GalN H-2), 2.72–2.34 (m, 4H; CH₂CO), 2.04 (s, 3H; COCH₃), 1.30,

1.28 ppm (2s, 6H; NHCOCH₃). The triol was O-sulfonated as described

for the preparation of 13 to give the trisulfate 14 (265 mg, 70% from 12)

as a white solid. R_f=0.35 (CH₂Cl₂/MeOH 6:1); [a]²_D²=+34 (c=0.5 in

methanol); ¹H NMR (400 MHz, CD₃OD/CDCl₃3:1): d=8.10–7.15 (m,

52H; arom. H), 5.82 (dd, J_2,3=J_3,4=9.5 Hz, 1H; GlcA^IIIH-3), 5.68, 5.62

CS-E hexasulfate 18: From hexaol 12 (144 mg, 70 mmol) as described for

the O-sulfonation of 13 to give the hexasulfate 18 (155 mg, 82%) as a

white powder. R_f=0.35 (EtOAc/MeOH/water 5:2:1); [a]²_D²=+21 (c=0.5

in water); ¹H NMR (400 MHz, D₂O, internal HOD, d_H=4.79): d=8.0–

7.23 (m, 37H; arom. H), 5.82 (dd, J_2,3=J_3,4=9.5 Hz, 1H; GlcA^IIIH-3),

5.62, 5.60 (2dd, J_2,3=J_3,4=9.5 Hz, 2H; GlcA^IH-3, GlcA^IIH-3), 5.52 (dd,

(2dd, J_2,3=J_3,4=9.5 Hz, 2H; GlcA^IH-3, GlcA^IIH-3), 5.58 (dd, J_4,5

=

9.5 Hz, 1H; GlcA^IIIH-4), 5.51 (dd, J_1,2=7.5 Hz, 1H; GlcA^IIIH-2), 5.48,

5.43 (2dd, J_1,2=7.5 Hz, 2H; GlcA^IH-2, GlcA^IIH-2), 5.15, 5.14, 5.12 (3d,

3H; 3GlcA H-1), 5.10, 4.99, 4.95 (3dd, J_3,4=3.5 Hz, J_4,5<1 Hz, 3H;

3GalN H-4), 4.94, 4.90, 4.85 (3d, J_1,2=8.0 Hz; 3GalN H-1), 4.86 (ABq,

2H; CH₂Ar), 4.70 (m, 3H; 3GalN H-6), 4.41 (d, 1H; GlcA^IIIH-5), 4.28,

4.26 (2d, 2H; GlcA^IH-5, GlcA^IIH-5), 4.22 (m, 2H; GlcA^IH-4, GlcA^II

H-4), 4.05–3.85 (m, 6H; 3GalN H-5, 3GalN H-6), 3.72, 3.68, 3.65 (3s,

9H; COOCH₃), 3.60–3.50 (m, 3H; 3GalN H-2), 2.70–2.32 (m, 4H;

CH₂CO), 2.02 (s, 3H; COCH₃), 1.31, 1.30, 1.28 ppm (3s, 9H;

J

_4,5=9.5 Hz, 1H; GlcA^IIIH-4), 5.41 (dd, J_1,2=7.5 Hz, 1H; GlcA^IIIH-2),

5.37, 5.36 (2dd, J_1,2=7.5 Hz, 2H; GlcA^IH-2, GlcA^IIH-2), 5.15 (d, 1H;

GlcA^IIIH-1), 5.05, 5.02 (2d, 2H; GlcA^IH-1, GlcA^IIH-1), 4.89, 4.78, 4.74

(3dd, J_3,4=3.5 Hz, J_4,5<1 Hz, 3H; 3GalN H-4), 4.86 (ABq, 2H; CH₂Ar),

4.54 (d, J_1,2=8.0 Hz, 1H; GalN H-1), 4.50 (m, 2H; GlcA^IH-4, GlcA^IIH-

4), 4.48 (d, 1H; GlcA^IIIH-5), 4.46, 4.45 (2d, J_1,2=8.0 Hz, 2H; 2GalN H-

1), 4.30 (m, 2H; 2GalN H-6), 4.23, 4.22 (2d, 2H; GlcA^IH-5, GlcA^IIH-

5), 4.0–3.80 (m, 7H; 3GalN H-2, 3GalN H-3, GalN H-5), 3.82, 3.79, 3.77

(3s, 9H; COOCH₃), 3.60–3.50 (m, 4H; 2GalN H-5, 2GalN H-6), 3.20 (m,

2H; 2GalN H-6), 2.75, 2.48 (2m, 4H; CH₂CO), 2.0 (s, 3H; COCH₃),

1.36, 1.28, 1.10 ppm (3s, 9H; NHCOCH₃); HRMS: m/z: calcd for

[C₁₀₃H₁₀₃N₃Na₆O₆₀S₆ꢀ5Na+5H]^5ꢀ: 511.2665; found: 511.2663.

NHCOCH₃); HRMS: m/z: calcd for [C₁₂₄H₁₁₈N₃Na₃O₅₄S₃ꢀ3Na+3H]^3ꢀ

:

869.5247; found: 869.5252.

CS-C disulfate 15: A mixture of the tetrol 11 (197 mg, 135 mmol) and

sulfur trioxide/trimethylamine complex (76 mg, 0.54 mmol) in anhydrous

DMF (6 mL) was stirred for 2 h 30 at 408C, then was cooled. Methanol

(0.5 mL) was added, and the mixture was concentrated. A mixture of the

residue, pyridine (4 mL), and Ac₂O (1.5 mL) was stirred overnight at RT,

then was concentrated. Flash silica chromatography (CH₂Cl₂/MeOH 4:1)

followed by ion-exchange as described for the preparation of 13 gave the

disulfate 15 (196 mg, 83%) as a white powder. [a]²_D²=+28 (c=1 in meth-

anol); ¹H NMR (400 MHz, CD₃OD/CDCl₃3:1): d=8.0–7.25 (m, 27H;

CS-A tetrasaccharide glycoside 19: A solution of ester 13 (220 mg,

117 mmol) in THF/water (3:1, 4 mL) was treated at 08C with a freshly

prepared mixture of hydrogen peroxide (30 wt% in water, 0.5 mL) and

LiOH (1m, 1 mL), and the mixture was stirred for 1 h at 08C and for

15 h at RT, and was then cooled to 08C. Methanol (1 mL) and NaOH

(4m, 2.5 mL) were added, and the mixture was stirred for 10 h at RT,

then was adjusted to pH 3 (pH meter monitoring) with Amberlite IR-120

[H⁺] resin, filtered, concentrated, and dried. The residue was stirred with

EtOH (5 mL), and the resulting solids were filtered off and washed with

EtOH. A solution of the residue in water (2 mL) was adjusted to pH 8

with NaOH (0.1m, pH meter monitoring) and was then eluted from a

column (3ꢄ80 cm) of Sephadex LH-20 with water to give the sodium salt

19 (112 mg, 82%) as a white powder. R_f=0.40 (EtOAc/MeOH/water

4:3:2); [a]²_D²=ꢀ39 (c=1 in water); ¹H NMR (400 MHz, D₂O, internal

HOD, d_H=4.79): d=8.0–7.40 (m, 7H; arom. H), 4.92 (ABq, 2H;

CH₂Ar), 4.78, 4.73 (2dd, J_3,4=3.5 Hz, J_4,5<1 Hz, 2H; 2GalN H-4), 4.57,

4.55 (2d, J_1,2=8.0 Hz, 2H; 2GalN H-1), 4.45 (d, J_1,2=7.5 Hz, 1H; GlcA^II

H-1), 4.38 (d, J_1,2=7.5 Hz, 1H; GlcA^IH-1), 4.02 (m, 3H; 2GalN H-2,

GalN H-3), 3.94 (dd, J_2,3=11.0 Hz, 1H; GalN H-3), 3.85–3.78 (m, 6H;

2GalN H-5, 4GalN H-6), 3.76 (dd, J_3,4=J_4,5=9.5 Hz, 1H; GlcA^IH-4), 3.64

(d, J_4,5=9.5 Hz, 1H; GlcA^IIH-5), 3.62 (d, 1H; GlcA^IH-5), 3.53 (m, 2H;

GlcA^IH-3, GlcA^IIH-4), 3.47 (dd, J_2,3=9.5 Hz, 1H; GlcA^IIH-3), 3.46

(dd, 1H; GlcA^IH-2), 3.43 (dd, 1H; GlcA^IIH-2), 2.01, 1.83 ppm (2s, 6H;

arom. H), 5.70 (dd, J_2,3=J_3,4=9.5 Hz, 1H; GlcA^IIH-3), 5.58 (dd, J_2,3

_3,4=9.5 Hz, 1H; GlcA^IH-3), 5.48, 5.32 (2dd, J_3,4=3.5 Hz, J_4,5<1 Hz,

=

J

2H; 2GalN H-4), 5.35 (dd, J_4,5=9.5 Hz, 1H; GlcA^IIH-4), 5.27 (m, 2H;

2GlcA H-2), 4.97 (d, J_1,2=7.5 Hz, 1H; GlcA^IIH-1), 4.94 (d, J_1,2=7.5 Hz,

1H; GlcA^IH-1), 4.86 (ABq, 2H; CH₂Ar), 4.68, 4.54 (2d, J_1,2=8.0 Hz;

2GalN H-1), 4.37 (dd, J_4,5=9.5 Hz, 1H; GlcA^IH-4), 4.29, 4.25 (2d, 2H;

2GlcA H-5), 4.24 (m, 2H; 2GalN H-3), 4.10 (m, 2H; 2GalN H-6), 3.95

(m, 2H; 2GalN H-5), 3.86, 3.78 (2s, 6H; COOCH₃), 3.80 (m, 2H; 2GalN

H-6), 3.52, 3.42 (2dd, J_2,3=11.0 Hz, 2H; 2GalN H-2), 2.72–2.30 (m, 4H;

CH₂CO), 2.03 (s, 3H; COCH₃), 1.98, 1.78 (2s, 6H; OCOCH₃), 1.30,

1.28 ppm (2s, 6H; NHCOCH₃); HRMS: m/z: calcd for

[C₇₈H₈₀N₂Na₂O₃₇S₂ꢀ2Na+2H]^2ꢀ: 850.1941; found: 850.1952.

CS-C trisulfate 16: From hexaol 12 (205 mg, 0.1 mmol) as described for

the preparation of 15 to give the trisulfate 16 (202 mg, 81%) as a white

powder. R_f=0.35 (CH₂Cl₂/MeOH 3:1); [a]²_D²=+24 (c=0.5 in methanol);

¹H NMR (400 MHz, CD₃OD/CDCl₃3:1): d=8.0–7.25 (m, 37H; arom.

H), 5.67 (dd, J_2,3=J_3,4=9.5 Hz, 1H; GlcA^IIIH-3), 5.55 (m, 2H; 2GlcA H-

3), 5.50, 5.30, 5.24 (3dd, J_3,4=3.5 Hz, J_4,5<1 Hz, 3H; 3GalN H-4), 5.32

(dd, J_4,5=9.5 Hz, 1H; GlcA^IIIH-4), 5.28 (dd, J_1,2=7.5 Hz, 1H; GlcA^IIIH-

2), 5.22 (m, 2H; 2GlcA H-2), 4.92, 4.91, 4.88 (3d, 3H; 3GlcA H-1), 4.84

(ABq, 2H; CH₂Ar), 4.57, 4.56, 4.49 (3d, J_1,2=8.0 Hz, 3H; 3GalN H-1),

NHCOCH₃); HRMS: m/z: calcd for [C₃₉H₄₈N₂Na₄O₂₉S₂ꢀ4Na+4H]^2ꢀ

:

537.0970; found: 537.0972.

CS-A hexasaccharide glycoside 20: From ester 14 (241 mg, 90 mmol) as

described for the preparation of 19 to give the sodium salt 20 (123 mg,

82%) as a white powder. R_f=0.35 (EtOAc/MeOH/water 4:3:2); [a]_D²²

=

9588

www.chemeurj.org

ꢁ 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Chem. Eur. J. 2009, 15, 9579 – 9595

Stereocontrolled Construction of Size-Defined Oligomers

FULL PAPER

1

ꢀ31 (c=1 in water); H NMR (400 MHz, D₂O, internal HOD, d_H=4.79):

CS-A tetrasaccharide 25: A solution of glycoside 19 (95 mg, 81 mmol) in

water (4 mL) was hydrogenolyzed in the presence of Pd/C catalyst

(50 mg) for 24 h at RT. The catalyst was removed by filtration through a

Celite pad, and the filtrate was concentrated. The residue was eluted

from a column (3ꢄ80 cm) of Sephadex LH-20 with water and lyophilized

to give the target tetrasaccharide 25 (79 mg, 95%) as a white foam. R_f=

0.30 (EtOAc/MeOH/water 4:3:2); [a]²_D²=ꢀ13 (c=1, equil., in water);

d=8.0–7.40 (m, 7H; arom. H), 4.94 (ABq, 2H; CH₂Ar), 4.78, 4.72 (2dd,

_3,4=3.5 Hz, J_4,5<1 Hz, 3H; 3GalN H-4), 4.58, 4.56, 4.54 (3d, J_1,2=

J

8.0 Hz, 3H; 3GalN H-1), 4.47, 4.45, 4.38 (3d, J_1,2=7.5 Hz, 3H; 3GlcA H-

1), 4.06–3.95 (m, 6H; 3GalN H-2, 3GalN H-3), 3.85–3.75 (m, 9H; 3GalN

H-5, 6GalN H-6), 3.74 (m, 2H; GlcA^IH-4, GlcA^IIH-4), 3.65, 3.64, 3.62

(3d, J_4,5=9.5 Hz, 3H; 3GlcA H-5), 3.56 (dd, J_3,4=9.5 Hz, 1H; GlcA^IIIH-

4), 3.51, 3.50 (2dd, J_2,3=J_3,4=9.5 Hz, 2H; GlcA^IH-3, GlcA^IIH-3), 3.45

(dd, J_2,3=9.5 Hz, 1H; GlcA^IIIH-3), 3.35, 3.34 (2dd, 3H; 3GlcA H-2),

2.02, 199, 1.82 ppm (3s, 9H; NHCOCH₃); HRMS: m/z: calcd for

[C₅₃H₆₇N₃Na₆O₄₃S₃ꢀ6Na+6H]^3ꢀ: 510.7515; found: 510.7518.

¹H NMR (400 MHz, D₂O, internal HOD, d_H=4.79): d=5.23 (d, J_1,2

=

3.5 Hz; GalN^IH-1a), 4.82, 4.78 (2dd, J_3,4=2.5 Hz, J_4,5<1 Hz, 1H; GalN^I

H-4a,H-4b), 4.81 (dd, J_3,4=2.5 Hz, J_4,5<1 Hz, 1H; GalN^IIH-4), 4.77 (d,

J

_1,2=8.0 Hz; GalN^IH-1b), 4.58 (d, J_1,2=8.0 Hz, 1H; GalN^IIH-1), 4.53,

4.51 (2d, J_1,2=7.5 Hz, 1H; GlcA^IH-1a,H-1b), 4.48 (d, J_1,2=7.5 Hz, 1H;

GlcA^IIH-1), 4.35 (d, J_2,3=11.0 Hz; GalN^IH-2a), 4.28 (m; GalN^IH-5a),

4.21 (dd; GalN^IH-3a), 4.10–4.02 (m; GalN^IH-2b, H-3b, GalN^IIH-2, H-

3), 3.90–3.78 (m; GalN^IH-5b, GalN^IIH-5, 2GalN H-6, GlcA^IH-4, 2GlcA

H-5), 3.68 (m, 2H; 2GalN H-6), 3.61, 3.49 (2dd, J_2,3=J_3,4=9.5 Hz, 2H;

2GlcA H-3), 3.54 (dd, J_4,5=9.5 Hz, 1H; GlcA^IIH-4), 3.42, 3.35 (2dd, 2H;

2GlcA H-2), 2.04, 2.02 ppm (2s, 6H; NHCOCH₃); HRMS: m/z: calcd for

[C₂₈H₄₀N₂Na₄O₂₉S₂ꢀ3Na+2H]^ꢀ: 957.1212; found: 957.1226.

CS-C tetrasaccharide glycoside 21: From ester 15 (190 mg, 108 mmol) as

described for the preparation of 19 to give the sodium salt 21 (105 mg,

83%) as a white powder. R_f=0.45 (EtOAc/MeOH/water 4:3:2); [a]_D²²

=

1

ꢀ23 (c=1 in water); H NMR (400 MHz, D₂O, internal HOD, d_H=4.79):

d=8.0–7.40 (m, 7H; arom. H), 4.94 (ABq, 2H; CH₂Ar), 4.52, 4.51 (2d,

J

_1,2=8.0 Hz, 2H; 2GalN H-1), 4.48 (d, J_1,2=7.5 Hz, 1H; GlcA^IIH-1), 4.43

(d, J_1,2=7.5 Hz, 1H; GlcA^IH-1), 4.30–4.22 (m, 4H; 4GalN H-6), 4.21,

4.14 (2dd, J_3,4=3.5 Hz, J_4,5<1 Hz, 2H; 2GalN H-4), 4.02, 4.01 (2dd, J_2,3

11.0 Hz, 2H; 2GalN H-2), 3.90 (m, 2H; 2GalN H-5), 3.83, 3.74 (2dd,

_2,3=11.0 Hz, 2H; 2GalN H-3), 3.67 (dd, J_3,4=J_4,5=9.5 Hz, 1H; GlcA^IH-

=

CS-A hexasaccharide 26: From glycoside 20 (90 mg, 54 mmol) as de-

scribed for the preparation of 25 to give the target hexasaccharide 26

(78 mg, 94%) as a white foam. R_f=0.25 (EtOAc/MeOH/water 4:3:2);

[a]²_D²=ꢀ20 (c=1, equil., in water); ¹H NMR (400 MHz, D₂O, internal

HOD, d_H=4.79): d=5.22 (d, J_1,2=3.5 Hz; GalN^IH-1a), 4.84, 4.79 (2dd,

J

4), 3.66, 3.64 (2d, 2H; 2GlcA H-5), 3.53 (dd, J_2,3=9.5 Hz, 1H; GlcA^IH-

3), 3.47 (m, 2H; GlcA^IIH-3, H-4), 3.34 (dd, 1H; GlcA^IIH-2), 3.32 (dd,

1H; GlcA^IH-2), 1.99, 1.80 ppm (2s, 6H; NHCOCH₃); HRMS: m/z:

calcd for [C₃₉H₄₈N₂Na₄O₂₉S₂ꢀ4Na+4H]^2ꢀ: 537.0970; found: 537.0979.

J

_3,4=2.5 Hz, J_4,5<1 Hz, 1H; GalN^IH-4a, H-4b), 4.81, 4.78 (2dd, J_3,4

=

2.5 Hz, J_4,5<1 Hz, 2H; 2GalN H-4), 4.75 (d, J_1,2=8.0 Hz; GalN^IH-1b),

4.59 (d, J_1,2=8.0 Hz, 2H; 2GalN H-1), 4.53, 4.51 (2d, J_1,2=7.5 Hz, 1H;

CS-C hexasaccharide glycoside 22: From ester 16 (190 mg, 76 mmol) as

described for the preparation of 19 to give the sodium salt 22 (103 mg,

GlcA^IH-1a, H-1b), 4.47 (d, J_1,2=7.5 Hz, 2H; 2GlcA H-1), 4.34 (d, J_2,3

=

81%) as a white powder. R_f=0.40 (EtOAc/MeOH/water 4:3:2); [a]_D²²

=

11.0 Hz; GalN^IH-2a), 4.27 (m; GalN^IH-5a), 4.19 (dd, J_2,3=11.0 Hz;

GalN^IH-3a), 4.08–4.01 (m; GalN^IH-2b, H-3b, 2GalN H-2, 2GalN H-3),

3.88–3.75 (m; GalN^IH-5b, 2GalN H-5, 4GalN H-6, 2GlcA H-4, 3GlcA

H-5), 3.68 (m, 2H; 2GalN H-6), 3.59, 3.57 (2dd, J_2,3=J_3,4=9.5 Hz, 2H;

1

ꢀ20 (c=1 in water); H NMR (400 MHz, D₂O, internal HOD, d_H=4.79):

d=8.0–7.40 (m, 7H; arom. H), 4.95 (ABq, 2H; CH₂Ar), 4.53, 4.52, 4.51

(3d, J_1,2=8.0 Hz, 3H; 3GalN H-1), 4.50, 4.49, 4.45 (3d, J_1,2=7.5 Hz, 3H;

3GlcA H-1), 4.30–4.20 (m, 6H; 6GalN H-6), 4.20, 4.17, 4.15 (3dd, J_3,4

=

2GlcA H-3), 3.54 (dd, J_4,5=9.5 Hz, 1H; GlcA^IIIH-4), 3.48 (d, J_2,3=J_3,4

=

3.0 Hz, J_4,5<1 Hz, 3H; 3GalN H-4), 4.07–3.98 (m, 3H; 3GalN H-2),

3.97–3.90 (m, 3H; 3GalN H-5), 3.85, 3.83, 3.76 (3dd, J_2,3=11.0 Hz, 3H;

3GalN H-3), 3.72 (m, 2H; GlcA^IH-4, GlcA^IIH-4), 3.70, 3.68, 3.65 (3d,

9.5 Hz, 1H; GlcA^IIIH-3), 3.41, 3.39, 3.37 (3dd, 3H; 3GlcA H-2), 2.05,

2.04, 2.02 ppm (3s, 9H; NHCOCH₃); ¹³C NMR (100 MHz, D₂O, internal

acetone, d_C=30.83): d=176.48, 175.54, 175.52, 175.49 (3GlcA C-6),

175.23, 175.05 (NHCO), 104.17, 104.0, 103.90 (3GlcA C-1), 101.38

(GalN^IIC-1, GalN^IIIC-1), 95.44 (GalN^IC-1b), 91.79 (GalN^IC-1a), 80.89,

80.85 (GlcA^IC-4, GlcA^IIC-4), 77.09, 77.0 (3GalN C-3), 76.95, 76.78

(3GalN C-4), 75.58 (3GalN C-5), 75.09, 75.05 (GlcA^IIC-3, 2GlcA C-5),

74.06, 74.01 (2GlcA C-3), 73.02 (GlcA^IIIC-4), 72.70, 72.65 (3GlcA C-2),

61.64, 61.50 (3GalN C-6), 52.10, 52.01, 49.88, 49.38 (3GalN C-2), 23.06,

23.03, 22.75, 22.54 ppm (NHCOCH₃); HRMS: m/z: calcd for

[C₄₂H₅₉N₃Na₆O₄₃S₃ꢀ5Na+5H]^2ꢀ: 707.5908; found: 707.5896.

J

_4,5=9.5 Hz, 3H; 3GlcA H-5), 3.60 (dd, J_3,4=9.5 Hz, 1H; GlcA^IIIH-4),

3.50 (m, 3H; 3GlcA H-3), 3.46, 3.45, 3.43 (3dd, J_2,3=9.5 Hz, 3H; 3GlcA

H-2), 2.02, 2.0, 1.83 ppm (3s, 9H; NHCOCH₃); HRMS: m/z: calcd for

[C₅₃H₆₇N₃Na₆O₄₃S₃ꢀ6Na+6H]^3ꢀ: 510.7515; found: 510.7503.

CS-E tetrasaccharide glycoside 23: From ester 17 (261 mg, 140 mmol) as

described for the preparation of 19 to give the sodium salt 23 (156 mg,

81%) as a white powder. R_f=0.35 (EtOAc/MeOH/water 4:3:2); [a]_D²²

=

1

ꢀ22 (c=1 in water); H NMR (400 MHz, D₂O, internal HOD, d_H=4.79):

d=8.0–7.40 (m, 7H; arom. H), 4.96 (ABq, 2H; CH₂Ar), 4.84, 4.78 (2dd,

CS-C tetrasaccharide 27: From glycoside 21 (99 mg, 85 mmol) as de-

scribed for the preparation of 25 to give the target tetrasaccharide 27

(83 mg, 88%) as a white foam. R_f=0.35 (EtOAc/MeOH/water 4:3:2);

[a]²_D²=ꢀ5 (c=1, equil., in water); ¹H NMR (400 MHz, D₂O, internal

J

_3,4=3.0 Hz, J_4,5<1 Hz, 2H; 2GalN H-4), 4.59, 4.57 (2d, J_1,2=8.0 Hz, 2H;

2GalN H-1), 4.46 (d, J_1,2=7.5 Hz, 1H; GlcA^IIH-1), 4.42 (d, J_1,2=7.5 Hz,

1H; GlcA^IH-1), 4.32–4.20 (m, 4H; 4GalN H-6), 4.11, 3.95 (2dd, J_2,3

11.0 Hz, 2H; 2GalN H-3), 4.07–4.0 (m, 4H; 2GalN H-2, 2H-5), 3.74 (dd,

_3,4=J_4,5=9.5 Hz, 1H; GlcA^IH-4), 3.66, 3.62 (2d, 2H; 2GlcA H-5), 3.55

=

HOD, d_H=4.79): d=5.22 (d, J_1,2=3.5 Hz; GalN^IH-1a), 4.68 (d, J_1,2

=

8.0 Hz; GalN^IH-1b), 4.57, 4.53 (2d, J_1,2=7.5 Hz, 1H; GlcA^IH-1a,H-1b),

4.55 (d, J_1,2=8.0 Hz, 1H; GalN^IIH-1), 4.51 (d, J_1,2=7.5 Hz, 1H; GlcA^II

H-1), 4.35 (m; GalN^IH-2a, GalN H-6), 4.28–4.15 (m; GalN^IH-3a, H-5a,

2GalN H-4, 3GalN H-6), 4.05–3.95 (m; GalN^IIH-2b, GalN^IH-2, 2GalN

H-5), 3.85 (m; GalN^IH-3b, GalN^IIH-3), 3.72 (m; GlcA^IH-4, 2GlcA H-

5), 3.60 (dd, J_2,3=J_3,4=9.5 Hz, 1H; GlcA^IH-3), 3.58 (m, 2H; GlcA^IIH-3,

H-4), 3.38 (m, 1H; GlcA^IH-2a,b), 3.31 (dd, J_2,3=9.5 Hz, 1H; GlcA^IIH-

2), 2.02, 2.01 ppm (2s, 6H; NHCOCH₃); HRMS: m/z: calcd for

[C₂₈H₄₀N₂Na₄O₂₉S₂ꢀ3Na+2H]^ꢀ: 957.1212; found: 957.1221.

J

(m, 2H; GlcA^IH-3, GlcA^IIH-4), 3.47 (dd, J_2,3=9.5 Hz, 1H; GlcA^IIH-3),

3.37(dd, J_2,3=9.5 Hz, 1H; GlcA^IH-2), 3.34 (dd, 1H; GlcA^IIH-2), 2.01,

1.93 ppm (2s, 6H; NHCOCH₃); HRMS: m/z: calcd for

[C₃₉H₄₆N₂Na₆O₃₅S₄ꢀ3Na+3H]^2ꢀ: 650.0268; found: 650.0262.

CS-E hexasaccharide glycoside 24: From ester 18 (150 mg, 56 mmol) as

described for the preparation of 19 to give the sodium salt 24 (92 mg,

84%) as a white powder. R_f=0.30 (EtOAc/MeOH/water 4:3:2); [a]_D²²

=

1

ꢀ21 (c=1 in water); H NMR (400 MHz, D₂O, internal HOD, d_H=4.79):

d=8.0–7.40 (m, 7H; arom. H), 4.96 (ABq, 2H; CH₂Ar), 4.96, 4.80, 4.78

CS-C hexasaccharide 28: From glycoside 22 (90 mg, 54 mmol) as de-

scribed for the preparation of 25 to give the target hexasaccharide 28

(78 mg, 95%) as a white foam. R_f=0.30 (EtOAc/MeOH/water 4:3:2);

[a]²_D²=ꢀ7 (c=1, equil., in water); ¹H NMR (400 MHz, D₂O, internal

(3dd, J_3,4=3.0 Hz, J_4,5<1 Hz, 3H; 3GalN H-4), 4.63, 4.61, 4.58 (3d, J_1,2

=

8.0 Hz, 3H; 3GalN H-1), 4.47, 4.43 (2d, J_1,2=7.5 Hz, 3H; 3GlcA H-1),

4.35–4.20 (m, 6H; 6GalN H-6), 4.18–4.03 (m, 8H; 3GalN H-2, 2GalN H-

3, 3GalN H-5), 3.98 (dd, J_2,3=11.0 Hz, 1H; GalN H-3), 3.78, 3.76 (2dd,

HOD, d_H=4.79): d=5.22 (d, J_1,2=3.5 Hz; GalN^IH-1a), 4.71 (d, J_1,2

=

_3,4=J_4,5=9.5 Hz, 2H; GlcA^IH-4, GlcA^IIH-4), 3.68, 3.66 (2d, 3H;

8.0 Hz; GalN^IH-1b), 4.57, 4.54 (2d, J_1,2=7.5 Hz, 1H; GlcA^IH-1a,H-1b),

4.55 (d, J_1,2=8.0 Hz, 2H; 2GalN H-1), 4.51 (d, J_1,2=7.5 Hz, 2H; 2GlcA

H-1), 4.30 (m; GalN^IH-2a, H-5a), 4.35–4.25 (m, 9H; 3GalN H-3, 6GalN

J

3GlcA H-5), 3.59 (dd, J_3,4=J_4,5=9.5 Hz, 1H; GlcA^IIIH-4), 3.55, 3.53, 3.49

(3dd, 3H; 3GlcA H-3), 3.38, 3.37, 3.35 (m, 3H; 3GlcA H-2), 2.08, 2.03,

1.86 ppm (3s, 9H; NHCOCH₃); HRMS: m/z: calcd for

[C₅₃H₆₄N₃Na₉O₅₂S₆ꢀ6Na+6H]^3ꢀ: 612.6903; found: 612.6896.

H-6), 4.05–3.96 (m, 5H; 2GalN H-2, 3GalN H-5), 3.87, 3.85 (2dd, J_3,4

=

2.5 Hz, J_4,5<1 Hz, 3H; 3GalN H-4), 3.72 (m, 5H; 2GlcA H-4, 3GlcA H-

Chem. Eur. J. 2009, 15, 9579 – 9595

ꢁ 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

www.chemeurj.org

9589

J.-C. Jacquinet et al.

5), 3.68 (m, 2H; GlcA^IIIH-4, GlcA H-3), 3.48 (m, 2H; 2GlcA H-3),

3.40–3.30 (m, 3H; 3GlcA H-2), 2.04, 2.03 ppm (2s, 9H; NHCOCH₃);

¹³C NMR (100 MHz, D₂O, internal acetone, d_C=30.83): d=176.41,

175.47, 175.43 (3GlcA C-6), 175.14, 174.80, 174.76, 174.68 (NHCO),

104.75, 104.60, 104, 52 (3GlcA C-1), 101.85 (GalN^IIC-1,GalN^IIIC-1),

95.62 (GalN^IC-1b), 91.74 (GalN^IC-1a), 81.78, 81.66 (GlcA^IC-4, GlcA^II

C-4), 80.49, 80.45, 80.41 (3GalN C-3), 77.46, 76.85, 76.82 (3GalN C-5),

76.58, 75.80 (3GlcA C-5), 74.38 (GlcA^IIIC-3), 74.32 (GlcA^IIIC-4), 73.21,

73.10 (2GlcA C-3), 72.85, 72.80, 72.28 (3GlcA C-2), 68.81, 68.63, 67.89

(3GalN C-4), 68.04, 67.97 (3GalN C-6), 52.68, 51.36, 51.32, 49.32 (3GalN

C-2), 23.04, 23.03, 22.74, 22.51 ppm (NHCOCH₃); HRMS: m/z: calcd for

[C₄₂H₅₉N₃Na₆O₄₃S₃ꢀ5Na+5H]^2ꢀ: 707.5908; found: 707.5916.

(m, 2H; 2GalN H-6), 3.75 (s, 3H; COOCH₃), 3.52 (m, 1H; GalN H-5),

2.65–2.29 (m, 4H; CH₂CO), 2.03 ppm (s, 3H; COCH₃); MS: m/z: 954

[M+Na]⁺for ³⁵Cl; elemental analysis calcd (%) for C₄₀H₄₁Cl₄NO₁₆: C

51.46, H 4.43, N 1.50; found: C 51.35, H 4.37, N 1.41.

2-Naphthylmethyl O-(methyl 3-O-benzoyl-2-O-chloroacetyl-4-O-levuli-

noyl-b-d-glucopyranosyluronate)-(1!3)-4-O-benzoyl-6-O-chloroacetyl-2-

deoxy-2-trichloroacetamido-b-d-galactopyranoside (32):

A solution of

freshly recrystallized chloroacetic anhydride (241 mg, 1.42 mmol) in an-

hydrous CH₂Cl₂(1 mL) was added dropwise at ꢀ208C within 20 min to a

solution of the diol 31 (1.03 g, 1.09 mmol) in anhydrous CH₂Cl₂(20 mL)

and pyridine (2 mL). Crushed ice was then added, and the mixture was

diluted with CH₂Cl₂(50 mL), washed with water, saturated aqueous

NaHCO₃and water, dried (MgSO₄), and concentrated. Crystallization of

the residue from EtOH gave the intermediate alcohol (882 mg, 80%).

M.p. 192–1938C. Benzoylation of the alcohol (880 mg, 0.87 mmol) as de-

scribed for the preparation of 2 followed by flash silica chromatography

(CH₂Cl₂/acetone 11:1) gave the ester 32 (923 mg, 76% from 31) as a

white foam. [a]²_D²=+22 (c=1 in chloroform); ¹H NMR (400 MHz,

CDCl₃): d=8.05–7.30 (m, 17H; arom. H), 6.91 (d, J=7.5 Hz, 1H; GalN

CS-E tetrasaccharide 29: From glycoside 23 (116 mg, 85 mmol) as de-

scribed for the preparation of 25 to give the target tetrasaccharide 29

(98 mg, 94%) as a white foam. R_f=0.25 (EtOAc/MeOH/water 4:3:2);

[a]²_D²=ꢀ1 (c=1, equil., in water); ¹H NMR (400 MHz, D₂O, internal

HOD, d_H=4.79): d=5.23 (d, J_1,2=3.5 Hz; GalN^IH-1a), 4.86 (m; GalN^I

H-4a, GalN^IIH-4), 4.81 (dd, J_3,4=2.5 Hz, J_4,5<1 Hz; GalN^IH-4b), 4.75

(d, J_1,2=8.0 Hz; GalN^IH-1b), 4.63 (d, J_1,2=8.0 Hz, 1H; GalN^IIH-1), 4.54,

4.53 (2d, J_1,2=7.5 Hz, 1H; GlcA^IH-1), 4.48 (d, J_1,2=7.5 Hz, 1H; GlcA^II

H-1), 4.35 (dd, J_2,3=11.0 Hz; GalN^IH-2a), 4.30–4.19 (m, GalN^IH-3a,

GalN^IH-5a, 4GalN H-6), 4.15–4.10 (m; GalN^IH-3b, GalN^IIH-3), 4.12–

4.04 (m; GalN^IH-2b, H-5b, GalN^IIH-2, H-5), 3.78 (dd, J_3,4=J_4,5=9.5 Hz,

1H; GlcA^IH-4), 3.68, 3.66 (2d, 2H; 2GlcA H-5), 3.62 (dd, J_2,3=9.5 Hz,

1H; GlcA^IH-3), 3.54 (dd, J_3,4=J_4,5=9.5 Hz, 1H; GlcA^IIH-4), 3.48 (dd,

NH), 5.67 (dd, J_3,4=3.5 Hz, J_4,5<1 Hz, 1H; GalN H-4), 5.37 (dd, J_2,3

_3,4=9.5 Hz, 1H; GlcA H-3), 5.31 (dd, J_4,5=9.5 Hz, 1H; GlcA H-4), 5.22

(dd, J_1,2=7.5 Hz, 1H; GlcA H-2), 4.96 (d, J_1,2=8.0 Hz, 1H; GalN H-

1),4.94 (ABq, 2H; CH₂Ar), 4.85 (dd, 1H; GlcA H-1), 4.65 (dd, J_2,3

=

J

=

11.0 Hz, 1H; GalN H-3), 4.35 (m, 2H; 2GalN H-6), 4.10 (s, 2H;

COCH₂Cl), 4.08 (d, 1H; GlcA H-5), 4.05 (m, 2H; GalN H-2, H-5), 3.92

(ABq, 2H; COCH₂Cl), 3.71 (s, 3H; COOCH₃), 2.65–2.29 (m, 4H;

CH₂CO), 2.01 ppm (s, 3H; COCH₃); MS: m/z: 1134 [M+Na]⁺for ³⁵Cl;

elemental analysis calcd (%) for C₄₉H₄₆Cl₅NO₁₈: C 52.82, H 4.16, N 1.26;

found: C 52.74, H 4.18, N 1.18.

J

_2,3=9.5 Hz, 1H; GlcA^IIH-3), 3.41 (dd, 1H; GlcA^IH-2), 3.36 (dd, 1H;

GlcA^IIH-2), 2.06, 2.03 ppm (2s, 6H; NHCOCH₃); HRMS: m/z: calcd for

[C₂₈H₃₈N₂Na₆O₃₅S₄ꢀ4Na+4H]^2ꢀ: 569.0045; found: 569.0060.

CS-E hexasaccharide 30: From glycoside 24 (85 mg, 43 mmol) as de-

scribed for the preparation of 25 to give the target hexasaccharide 30

(75 mg, 95%) as a white foam. R_f=0.20 (EtOAc/MeOH/water 4:3:2);

[a]²_D²=ꢀ5 (c=1, equil., in water); ¹H NMR (400 MHz, D₂O, internal

HOD, d_H=4.79): d=5.23 (d, J_1,2=3.5 Hz; GalN^IH-1a), 4.84 (m; GalN^I

H-4a, GalN H-4), 4.79 (dd, J_3,4=2.5 Hz, J_4,5<1 Hz, 1H; GalN H-4), 4.78

(dd, J_3,4=2.8 Hz, J_4,5<1 Hz; GalN^IH-4b), 4.73 (d, J_1,2=8.0 Hz; GalN^IH-

O-(Methyl 3-O-benzoyl-2-O-chloroacetyl-4-O-levulinoyl-b-d-glucopyra-

nosyluronate)-(1!3)-4-O-benzoyl-6-O-chloroacetyl-2-deoxy-2-trichloro-

AHCTUNGTERGaNNUN cetamido-1-O-trichloroacetimidoyl-a-d-galactopyranose (33): From gly-

coside 32 (776 mg, 0.7 mmol) as described for the preparation of 7 to

give imidate 32 (518 mg, 66%) as a white foam. R_f=0.40 (EtOAc/petro-

leum ether 1:1); [a]²_D²=+76 (c=1 in chloroform); ¹H NMR (400 MHz,

CDCl₃): d=8.80 (s, 1H; C=NH), 7.08 (d, J=8.0 Hz, 1H; GalN NH), 6.68

(d, J_1,2=3.5 Hz, 1H; GalN H-1), 5.64 (dd, J_3,4=3.5 Hz, J_4,5<1 Hz, 1H;

GalN H-4), 5.47 (dd, J_2,3=J_3,4=9.5 Hz, 1H; GlcA H-3), 5.30 (m, 2H;

1b), 4.62, 4.61 (2d, J_1,2=8.0 Hz, 2H; 2GalN H-1), 4.54, 4.52 (2d, J_1,2

=

7.5 Hz, 1H; GlcA^IH-1), 4.49, 4.48 (2 d, J_1,2=7.5 Hz, 2H; 2GlcA H-1),

4.36 (dd, J_2,3=11.0 Hz; GalN^IH-2a), 4.30–4.18 (m, GalN^IH-3a, GalN^I

H-5a, 6GalN H-6), 4.15–4.10 (m; GalN^IH-3b, 2GalN H-3), 4.09–4.02 (m;

GalN^IH-2b, H-5b, 2GalN H-2, H-5), 3.77, 3.76 (2dd, J_3,4=J_4,5=9.5 Hz,

2H; GlcA^IH-4, GlcA^IIH-4), 3.68, 3.67, 3.66 (3d, J_4,5=9.5 Hz, 3H;

GlcA H-2, H-4), 4.96 (d, J_1,2=7.5 Hz, 1H; GlcA H-1), 4.75 (m, J_2,3

=

11.0 Hz, 1H; GalN H-2), 4.58 (dd, 1H; GalN H-3), 4.52 (m, 1H; GalN

H-5), 4.75 (m, 2H; 2GalN H-6), 4.28 (d, J_4,5=9.5 Hz, 1H; GlcA H-5),

4.08 (ABq, 2H; COCH₂Cl), 4.07 (s, 2H; COCH₂Cl), 3.72 (s, 3H;

COOCH₃), 2.68–2.26 (m, 4H; CH₂CO), 2.02 ppm (s, 3H; COCH₃); ele-

mental analysis calcd (%) for C₄₀H₃₈Cl₈N₂O₁₈: C 42.96, H 3.43, N 2.50;

found: C 42.68, H 3.21, N 2.40.

3GlcA H-5), 3.60 (m, 2H; GlcA^IIIH-4, GlcA H-3), 3.52, 3.47 (2dd, J_2,3

=

9.5 Hz, 2H; 2GlcA H-3), 3.42–3.33 (m, 3H; 3GlcA H-2), 2.05, 2.03,

2.01 ppm (3s, 9H; NHCOCH₃); ¹³C NMR (100 MHz, D₂O, internal ace-

tone, d_C=30.83): d=176.20, 175.34, 175.29 (3GlcA C-6), 175.01, 174.85,

174.75 (NHCO), 104.07, 103.89, 103.84 (3GlcA C-1), 101.94, 101.90

(GalN^IIC-1, GalN^IIIC-1), 95.37 (GalN^IC-1b), 91.71 (GalN^IC-1a), 82.56,

82.51 (3GlcA C-4), 77.65, 76.94 (3GalN C-3), 76.47, 76.42 (3GalN C-4),

75.76, 75.69 (3GlcA C-5), 75.23, 75.21, 75.18 (3GalN C-5), 74.16 (GlcA^III

C-3), 72.97, 72.92 (GlcA^IC-3, GlcA^IIC-3), 72.74 (GlcA^IIIC-4), 72.40,

72.34, 72.21 (3GlcA C-2), 68.64, 68.57, 68.07 (3GalN C-6), 53.01, 51.81,

51.72, 49.68 (3GalN C-2), 23.01, 22.99, 22.67, 22.47 ppm (NHCOCH₃);

HRMS: m/z: calcd for [C₄₂H₅₆N₃Na₉O₅₂S₆ꢀ5Na+5H]^2ꢀ: 860.4990; found:

860.5004.

2-Naphthylmethyl O-(methyl 3-O-benzoyl-2-O-chloroacetyl-b-d-gluco-

pyranosyluronate)-(1!3)-4-O-benzoyl-6-O-chloroacetyl-2-deoxy-2-tri-

chloroacetamido-b-d-galactopyranoside (34): From ester 32 (556 mg,

0.5 mmol) as described for the preparation of 6. Flash silica chromatogra-

phy (EtOAc/petroleum ether 3:2) gave the alcohol 34 (420 mg, 82%) as

a white foam. [a]²_D²=+32 (c=1 in chloroform); ¹H NMR (400 MHz,

CDCl₃): d=8.05–7.32 (m, 17H; arom. H), 6.94 (d, J=7.5 Hz, 1H; GalN

NH), 5.84 (dd, J_3,4=3.5 Hz, J_4,5<1 Hz, 1H; GalN H-4), 5.59 (dd, J_2,3

=

J

_3,4=9.5 Hz, 1H; GlcA H-3), 5.53 (dd, J_1,2=7.5 Hz, 1H; GlcA H-2), 4.99

(d, J_1,2=8.0 Hz, 1H; GalN H-1), 4.94 (ABq, 2H; CH₂Ar), 4.88 (d, 1H;

GlcA H-1), 4.64 (dd, J_2,3=11.0 Hz, 1H; GalN H-3), 4.28 (m, 2H; 2GalN

H-6), 4.04 (s, 2H; COCH₂Cl), 4.03–3.96 (m, 3H; GalN H-2, H-5, GlcA

H-4), 3.90 (ABq, 2H; COCH₂Cl), 3.78 (s, 3H; COOCH₃), 3.20 ppm (d,

2-Naphthylmethyl O-(methyl 3-O-benzoyl-2-O-chloroacetyl-4-O-levuli-

noyl-b-d-glucopyranosyluronate)-(1!3)-2-deoxy-2-trichloroacetamido-b-

d-galactopyranoside (31): The alcohol 3 (1.84 g, 1.95 mmol) was chloroa-

cetylated as described for the preparation of 5. A suspension of the crude

intermediate in AcOH/water (4:1, 50 mL) was stirred at 808C for 30 min,

then was cooled and concentrated. Recrystallization of the residue from

hot EtOH gave the diol 31 (1.51 g, 83%). R_f=0.40 (CH₂Cl₂/MeOH

12:1); m.p.162–1648C; [a]²_D²=ꢀ16 (c=1 in methanol); ¹H NMR

J

_4,OH=3.0 Hz; GlcA HO-4); MS: m/z: 1036 [M+Na]⁺for ³⁵Cl; elemental

analysis calcd (%) for C₄₄H₄₀Cl₅NO₁₆: C 52.01, H 3.97, N 1.38; found: C

51.91, H 3.91, N 1.21.

CS-D tetrasaccharide 35: From imidate 33 (515 mg, 0.46 mmol) and alco-

hol 34 (365 mg, 0.36 mmol) as described for the preparation of 8. Flash

silica chromatography (EtOAc/petroleum ether 3:2, containing 0.1% of

(400 MHz, CD₃OD): d=8.0–7.40 (m, 12H; arom. H), 5.43 (dd, J_2,3=J_3,4

9.5 Hz, 1H; GlcA H-3), 5.30 (dd, J_4,5=9.5 Hz, 1H; GlcA H-4), 5.22 (dd,

_1,2=7.5 Hz, 1H; GlcA H-2), 4.96 (ABq, 2H; CH₂Ar), 4.88 (d, 1H; GlcA

=

J

NEt₃) gave the tetrasaccharide 35 (483 mg, 68%) as a white foam. [a]_D²²

=

H-1), 4.76 (d, J_1,2=8.0 Hz, 1H; GalN H-1), 4.22 (d, 1H; GlcA H-5), 4.18

(dd, J_2,3=11.0 Hz, 1H; GalN H-2), 4.08 (ABq, 2H; COCH₂Cl), 4.06 (dd,

+7 (c=1 in chloroform); ¹H NMR (400 MHz, CDCl₃): d=8.05–7.02 (m,

27H; arom. H), 6.94, 6.87 (2d, J=7.5 Hz, 2H; 2GalN NH), 5.68, 5.40

J

_3,4=3.5 Hz, J_4,5<1 Hz, 1H; GalN H-4), 4.02 (dd, 1H; GalN H-3), 3.85

(2dd, J_3,4=3.5 Hz, J_4,5<1 Hz, 2H; 2GalN H-4), 5.36 (dd, J_2,3=J_3,4=

9590

www.chemeurj.org

ꢁ 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Chem. Eur. J. 2009, 15, 9579 – 9595

Stereocontrolled Construction of Size-Defined Oligomers

FULL PAPER

9.5 Hz, 1H; GlcA^IIH-3), 5.33 (dd, J_2,3=J_3,4=9.5 Hz, 1H; GlcA^IH-3),

5.30 (dd, J_4,5=9.5 Hz, 1H; GlcA^IIH-4), 5.02, 4.94 (2d, J_1,2=8.0 Hz, 2H;

2GalN H-1), 4.98 (m, 2H; 2GlcA H-2), 4.91 (ABq, 2H; CH₂Ar), 4.76,

4.74 (2d, J_1,2=7.5 Hz, 2H; 2GlcA H-1), 4.68, 4.38 (2dd, J_2,3=11.0 Hz,

2H; 2GalN H-3), 4.42 (dd, J_gem=12.0 Hz, J_vic=5.0 Hz,1H; GalN H-6),

4.38 (dd, J_vic=7.0 Hz,1H; GalN H-6), 4.19 (dd, J_4,5=9.5 Hz, 1H; GlcA^I

H-4), 4.10–3.90 (m, 13H; 2GalN H-2, 4 COCH₂Cl, COOCH₃), 3.82 (m,

2H; CH₂Ar), 4.74, 4.57 (2d, J_1,2=8.0 Hz, 2H; 2GalN H-1), 4.43 (m, 2H;

2GlcA H-2), 4.32 (m, 2H; 2GalN H-3), 4.24 (dd, J_4,5=9.5 Hz, 1H; GlcA^I

H-4), 4.24–4.16 (m, 4H; 4 GalN H-6), 4.17, 4.13 (2d, 2H; 2GlcA H-5),

3.83–3.78 (m, 2H; 2GalN H-5), 3.72, 3.58 (2s, 6H; 2COOCH₃), 3.70–3.63

(m, 2H; 2GalN H-2), 2.62–2.24 (m, 4H; CH₂CO), 2.01, 2.0 ppm (2s, 9H;

COCH₃,

2NHCOCH₃);

HRMS:

m/z:

calcd

for

[C₇₄H₇₄N₂Na₄O₄₁S₄ꢀ4Na+4H]^2ꢀ: 888.1403; found: 888.1406.

2H; 2GalN H-5), 3.66 (s, 3H; COOCH₃), 3.38 (dd, J_gem=12.0 Hz, J_vic

=

CS-D disaccharide glycoside 40: From ester 38 (75 mg, 70 mmol) as de-

scribed for the preparation of 19 to give the sodium salt 40 (49 mg, 90%)

as a white powder. R_f=0.40 (EtOAc/MeOH/water 5:3:2); [a]²_D²=ꢀ21

(c=1 in water); ¹H NMR (400 MHz, D₂O, internal HOD, d_H=4.79): d=

7.0 Hz,1H; GalN H-6), 3.14 (dd, J_vic=7.5 Hz,1H; GalN H-6), 2.60–2.24

(m, 4H; CH₂CO), 2.02 ppm (s, 3H; COCH₃); elemental analysis calcd

(%) for C₈₂H₇₆Cl₁₀N₂O₃₃: C 49.94, H 3.88, N 1.42; found: C 49.82, H 3.71,

N 1.31.

8.0–7.40 (m, 7H; arom. H), 4.92 (ABq, 2H; CH₂Ar), 4.61 (d, J_1,2

=

7.5 Hz, H; GlcA H-1), 4.57 (d, J_1,2=8.0 Hz, 1H; GalN H-1), 4.28–4.23

(m, 2H; 2GalN H-6), 4.20 (dd, J_3,4=3.0 Hz, J_4,5<1 Hz, H; GalN H-4),

4.03 (dd, J_2,3=9.5 Hz, 1H; GlcA H-2), 3.92–3.83 (m, 3H; GalN H-2, H-3,

H-5), 3.68 (d, J_4,5=9.5 Hz, 1H; GlcA H-5), 3.65 (dd, J_3,4=9.5 Hz, 1H;

GlcA H-3), 3.53 (dd, 1H; GlcA H-4), 1.78 ppm (s, 3H; NHCOCH₃);

HRMS: m/z: calcd for [C₂₅H₂₈NNa₃O₁₈S₂ꢀ2Na+H]^ꢀ: 718.0724; found:

718.0721.

CS-D disaccharide acetamide 36: From ester 32 (150 mg, 135 mmol) as

described for the preparation of 11. Flash silica chromatography

(CH₂Cl₂/MeOH 19:1) gave the intermediate diol (110 mg, 85%) as a

white foam. MS: m/z: 982 [M+Na]⁺for ³⁵Cl. The diol (108 mg,

112 mmol) was reduced as described for the preparation of 11. Flash silica

chromatography (CH₂Cl₂/MeOH 15:1) gave the acetamide 36 (83 mg,

73% from 32) as a white foam. [a]²_D²=+52 (c=1 in methanol); H NMR

1

(400 MHz, CD₃OD): d=8.10–7.31 (m, 17H; arom. H), 5.66 (dd, J_3,4

=

CS-D tetrasaccharide glycoside 41: From ester 39 (150 mg, 80 mmol) as

described for the preparation of 19 to give the sodium salt 41 (89 mg,

3.5 Hz, J_4,5<1 Hz, 1H; GalN H-4), 5.28 (dd, J_2,3=J_3,4=9.5 Hz, 1H; GlcA

H-3), 5.14 (dd, J_4,5=9.5 Hz, 1H; GlcA H-4), 4.96 (ABq, 2H; CH₂Ar),

4.63 (d, J_1,2=8.0 Hz, 1H; GalN H-1), 4.57 (d, J_1,2=7.5 Hz, 1H; GlcA H-

1), 4.31 (dd, J_2,3=11.0 Hz, 1H; GalN H-2), 4.15 (d, 1H; GlcA H-5), 4.07

(dd, 1H; GalN H-3), 3.78 (m, 1H; GalN H-5), 3.72 (s, 3H; COOCH₃),

3.65 (m, 2H; 2GalN H-6); 3.51 (dd, 1H; GlcA H-2), 2.60–2.22 (m, 4H;

CH₂CO), 2.04 (s, 3H; COCH₃), 1.96 ppm (s, 3H; NHCOCH₃); MS: m/z:

881 [M+Na]⁺; elemental analysis calcd (%) for C₄₅H₄₇NO₁₆: C 63.00, H

5.52, N 1.63; found: C 62.90, H 5.41, N 1.51.

81%) as a white powder. R_f=0.30 (EtOAc/MeOH/water 5:3:2); [a]_D²²

=

1

ꢀ23 (c=1 in water); H NMR (400 MHz, D₂O, internal HOD, d_H=4.79):

d=8.0–7.40 (m, 7H; arom. H), 4.94 (ABq, 2H; CH₂Ar), 4.71 (d, J_1,2

=

7.5 Hz, 1H; GlcA^IIH-1), 4.64 (d, J_1,2=7.5 Hz, 1H; GlcA^IH-1), 4.57, 4.55

(2d, J_1,2=8.0 Hz, 2H; 2GalN H-1), 4.27–4.19 (m, 4H; 4GalN H-6), 4.18,

4.16 (2dd, J_3,4=2.5 Hz, J_4,5<1 Hz, 2H; 2GalN H-4), 4.08, 4.06 (2dd, J_2,3

=

9.5 Hz; 2H; GlcA^IH-2, GlcA^IIH-2), 3.95–3.86 (m, 6H; 2GalN H-2, H-3,

H-5), 3.83 (dd, J_4,5=9.5 Hz, 1H; GlcA^IH-4), 3.76, 3.74 (2d, 2H; GlcA^I

H-5, GlcA^IIH-5), 3.73, 3.72 (2dd, 2H; GlcA^IH-3, GlcA^IIH-3), 3.57 (dd,

1H; GlcA^IIH-4), 2.0, 1.80 ppm (2s, 6H; NHCOCH₃); HRMS: m/z: calcd

for [C₃₉H₄₆N₂Na₆O₃₅S₄ꢀ4Na+4H]^2ꢀ: 639.0358; found: 639.0363.

CS-D tetrasaccharide acetamide 37: From ester 35 (296 mg, 150 mmol) as

described for the preparation of 11. Flash silica chromatography (EtOAc/

CH₂Cl₂6:1) gave the intermediate tetrol (205 mg, 82%) as a white foam.

[a]²_D²=+20 (c=1 in chloroform); MS: m/z: 1686 [M+Na]⁺for ³⁵Cl. The

tetrol (200 mg, 120 mmol) was reduced as described for the preparation of

11. Flash silica chromatography (CH₂Cl₂/MeOH 14:1) gave the acet-

amide 37 (140 mg, 66% from 35). M.p. 205–2078C (from 2-propanol);

[a]²_D²=+22 (c=0.5 in methanol); ¹H NMR (400 MHz, CD₃OD/CDCl₃

CS-D disaccharide 42: From glycoside 40 (31 mg, 40 mmol) as described

for the preparation of 25 to give the target disaccharide 42 (23 mg, 92%)

as a white powder. R_f=0.35 (EtOAc/MeOH/water 4:3:2); physical data

identical to those previously reported.^[6f]

CS-D tetrasaccharide 43: From glycoside 41 (70 mg, 51 mmol) as de-

scribed for the preparation of 25 to give the target tetrasaccharide 43

(57 mg, 90%) as a white powder. R_f=0.30 (EtOAc/MeOH/water 4:3:2);

[a]²_D²=+2 (c=1, equil., in water); ¹H NMR (400 MHz, D₂O, internal

HOD, d_H=4.79): d=5.33 (d, J_1,2=3.5 Hz; GalN^IH-1a), 4.85, 4.76 (2d,

3:1): d=8.10–7.0 (m, 27H; arom. H), 5.64, 5.42 (2dd, J_3,4=3.5 Hz, J_4,5

<

1 Hz, 2H; 2GalN H-4), 5.28 (dd, J_2,3=J_3,4=9.5 Hz, 1H; GlcA^IIH-3), 5.22

(dd, J_2,3=J_3,4=9.5 Hz, 1H; GlcA^IH-3), 5.14 (dd, J_4,5=9.5 Hz, 1H; GlcA^II

H-4), 4.96 (ABq, 2H; CH₂Ar), 4.64, 4.58 (2d, J_1,2=8.0 Hz, 2H; 2GalN

J

_1,2=7.5 Hz, 1H; GlcA^IH-1a,H-1b), 4.74 (d, J_1,2=8.0 Hz; GalN^IH-1b),

H-1), 4.54, 4.52 (2d, J_1,2=7.5 Hz, 2H; 2GlcA H-1),4.32, 4.30 (2dd, J_2,3

=

11.0 Hz, 2H; 2GalN H-2), 4.20–4.10 (m, 3H; GalN H-3, GlcA^IH-4, H-

5), 4.04 (d, J_4,5=9.5 Hz, 1H; GlcA^IIH-5), 4.0–3.90 (m, 3H; GalN H-3,

2GalN H-6), 3.86, 3.68 (2s, 6H; 2COOCH₃), 3.75 (m, 2H; 2GalN H-5),

3.65–3.58 (m, 2H; 2GalN H-6), 3.48 (m, 2H; 2GlcA H-2), 2.80–2.32 (m,

4H; CH₂CO), 1.98 (s, 3H; COCH₃), 1.12, 1.10 ppm (2s, 6H;

2NHCOCH₃); MS: m/z: 1459 [M]^ꢀ; elemental analysis calcd (%) for

C₇₄H₇₈N₂O₂₉: C 60.90, H 5.39, N 1.92; found: C 60.70, H 5.41, N 1.71.

4.73 (d, J_1,2=7.5 Hz, 1H; GlcA^IIH-1), 4.59 (d, J_1,2=8.0 Hz, 1H; GalN^II

H-1), 4.32 (dd, J_2,3=11.0 Hz; GalN^IH-2a), 4.29–4.19 (m, 8H; 2GalN H3,

H-4, 4GalN H-6), 4.16, 4.14 (2dd, J_2,3=9.5 Hz,1H; GlcA^IH-2a,b), 4.08

(dd, J_2,3=9.5 Hz,1H; GlcA^IIH-2), 4.0–3.90 (m; GalN^IH-2b, GalN^IIH-2,

GlcA^IH-4), 3.86–3.80 (m, 2H; 2GalN H-5), 3.77–3.70 (m, 4H; 2GlcA H-

3, H-5), 3.59 (dd,

J

_3,4=9.5 Hz, 1H; GlcA^IIH-4), 2.01 ppm (s, 6H;

NHCOCH₃); ¹³C NMR (100 MHz, D₂O, internal acetone, d_C=30.83): d=

176.01, 175.26 (2GlcA C-6), 174.97, 174.53 (NHCO), 101.92, 101.59, 101.

51 (2GlcA C-1), 101.46 (GalN^IIC-1), 95.79 (GalN^IC-1b), 91.14 (GalN^I

C-1a), 80.14, 79.96 (GlcA^IC-4, GalN C-3), 79.83 (GalN C-3), 76.98,

76.83 (2GlcA C-2), 76.28 (GlcA C-5), 74.96 (2GalN C-5, GlcA C-5),

73.11 (GlcA^IIC-3), 72.94 (GlcA^IC-3), 72.68 (GlcA^IIC-4), 68.61, 67.84,

67.34 (2GalN C-4), 68.44, 68.17, 67.57 (2GalN C-6), 52.67, 51.06, 49, 47

(2GalN C-2), 23.10, 22.80, 22.42 ppm (NHCOCH₃); HRMS: m/z: calcd

for [C₂₈H₃₈N₂Na₆O₃₅S₄ꢀ4Na+4H]^2ꢀ: 569.0045; found: 569.0055.

CS-D disulfate 38: From diol 36 (70 mg, 81 mmol) as described for the

preparation of 13 to give the disulfate 38 (78 mg, 90%) as a colorless

glass. R_f=0.40 (CH₂Cl₂/MeOH 3:1); [a]²_D²=+30 (c=1 in methanol);

¹H NMR (400 MHz, CD₃OD/CDCl₃3:1): d=8.05–7.20 (m, 17H; arom.

H), 5.71 (dd, J_3,4=3.0 Hz, J_4,5<1 Hz, 1H; GalN H-4), 5.48 (dd, J_2,3=J_3,4

9.5 Hz, 1H; GlcA H-3), 5.19 (dd, J_4,5=9.5 Hz, 1H; GlcA H-4), 4.96

(ABq, 2H; CH₂Ar), 4.94 (d, J_1,2=7.5 Hz, 1H; GlcA H-1), 4.67 (d, J_1,2

8.0 Hz, 1H; GalN H-1), 4.43 (dd, 1H; GlcA H-2), 4.32 (dd, J_2,3=11.0 Hz,

1H; GalN H-3), 4.22 (d, 1H; GlcA H-5), 4.18–4.10 (m, 2H; 2GalN H-6),

4.09–4.03 (m, 2H; GalN H-2, H-5), 3.58 (s, 3H; COOCH₃), 2.60–2.22 (m,

4H; CH₂CO), 2.0, 1.98 ppm (2s, 6H; COCH₃, NHCOCH₃); HRMS: m/z:

calcd for [C₄₅H₄₅NNa₂O₂₂S₂ꢀ2Na+2H]^2ꢀ: 507.5937; found: 507.5944.

CS-D tetrasulfate 39: From tetrol 37 (132 mg, 90 mmol) as described for

the preparation of 13 to give the tetrasulfate 39 (148 mg, 88%) as a

white glass. R_f=0.30 (CH₂Cl₂/MeOH 5:2); [a]²_D²=+4 (c=1 in methanol);

¹H NMR (400 MHz, CD₃OD/CDCl₃3:1): d=8.05–7.0 (m, 27H; arom.

H), 5.82, 5.64 (2dd, J_3,4=3.0 Hz, J_4,5<1 Hz, 2H; 2GalN H-4), 5.49, 5.47

(2dd, J_2,3=J_3,4=9.5 Hz, 2H; 2GlcA H-3), 5.17 (dd, J_4,5=9.5 Hz, 1H;

GlcA^IIH-4), 4.97, 4.88 (2d, J_1,2=7.5 Hz, 2H; 2GlcA H-1), 4.95 (ABq,

=

2-Naphthylmethyl O-(methyl 2-O-benzoyl-4-O-levulinoyl-b-d-glucopyra-

nosyluronate)-(1!3)-2-acetamido-2-deoxy-b-d-galactopyranoside

(44):

From alcohol 4 (472 mg, 0.5 mmol) as described for the preparation of 11

to give the intermediate acetamide (390 mg, 90%). R_f=0.40 (CH₂Cl₂/

MeOH 15:1); m.p. 212–2138C (from MeOH); MS: m/z: 865 [M+Na]⁺.

The intermediate (380 mg, 0.45 mmol) was treated as described for the

preparation of 31 and crystallized from MeOH to give the triol 44

(306 mg, 80% from 4). M.p. 218–2208C; [a]²_D²=ꢀ32 (c=0.5 in metha-

nol); ¹H NMR (400 MHz, CD₃OD/CDCl₃3:1): d=8.02–7.30 (m, 12H;

arom. H), 5.13 (dd, J_1,2=7.5 Hz, J_2,3=9.5 Hz,1H; GlcA H-2), 5.02 (dd,

J

_3,4=J_4,5=9.5 Hz, 1H; GlcA H-4), 4.84 (ABq, 2H; CH₂Ar), 4.78 (d, 1H;

Chem. Eur. J. 2009, 15, 9579 – 9595

ꢁ 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

www.chemeurj.org

9591

J.-C. Jacquinet et al.

GlcA H-1), 4.76 (d, J_1,2=8.0 Hz, 1H; GalN H-1), 4.22 (dd, J_2,3=11.0 Hz,

_3,4=3.0 Hz, 1H; GalN H-3), 4.10 (dd, J_4,5<1 Hz, 1H; GalN H-4), 4.08

GlcA H-5), 3.49 (dd, 1H; GlcA H-2), 1.82 ppm (s, 3H; NHCOCH₃);

HRMS: m/z: calcd for [C₂₅H₂₈NNa₃O₁₈S₂ꢀ2Na+H]^ꢀ: 718.0724; found:

718.0735.

J

(d, 1H; GlcA H-5), 3.92 (dd, 1H; GlcA H-3), 3.80 (m, 2H; 2GalN H-6),

3.74 (s, 3H; COOCH₃), 3.54 (m, 2H; GalN H-2, H-5), 2.80–2.45 (m, 4H;

CH₂CO), 2.08 (s, 3H; COCH₃), 1.24 ppm (s, 3H; NHCOCH₃); MS: m/z:

777 [M+Na]⁺; elemental analysis calcd (%) for C₃₈H₄₃NO₁₅: C 60.55, H

5.75, N 1.86; found: C 60.41, H 5.70, N 1.71.

CS-L disaccharide glycoside 49: From ester 46 (96 mg, 0.1 mmol) as de-

scribed for the preparation of 19 to give the sodium salt 49 (66 mg, 86%)

as a white powder. R_f=0.40 (EtOAc/MeOH/water 4:2:1); [a]²_D²=ꢀ26

(c=1 in water); ¹H NMR (400 MHz, D₂O, internal HOD, d_H=4.79): d=

8.0–7.40 (m, 7H; arom. H), 4.94 (ABq, 2H; CH₂Ar), 4.52 (d, J_1,2

8.0 Hz, 1H; GalN H-1), 4.51 (d, J_1,2=7.5 Hz, 1H; GlcA H-1), 4.46 (m,

2H; 2GalN H-6), 4.42 (dd, J_2,3=J_3,4=9.5 Hz, 1H; GlcA H-3), 4.18 (dd,

=

Sodium 2-naphthylmethyl O-(sodium methyl 2-O-benzoyl-4-O-levulino-

yl-3-O-sulfonato-b-d-glucopyranosyluronate)-(1!3)-2-acetamido-2-

deoxy-6-O-benzoyl-4-O-sulfonato-b-d-galactopyranoside (45): From triol

44 (98 mg, 0.12 mmol) as described for the preparation of 13 to give the

intermediate 6-benzoate (102 mg, 91%): R_f=0.40 (CH₂Cl₂/MeOH 12:1);

m.p. 230–2328C (from EtOH); MS: m/z: 881 [M+Na]⁺. The intermediate

(100 mg, 116 mmol) was O-sulfonated as described for the preparation of

13 to give the disulfate 45 (102 mg, 80% from 44) as a white powder.

R_f=0.30 (CH₂Cl₂/MeOH 3:1); [a]²_D²=+3 (c=0.5 in methanol); ¹H NMR

(400 MHz, CD₃OD/CDCl₃3:1): d=8.05–7.25 (m, 17H; arom. H), 5.34

(dd, J_1,2=7.5 Hz, J_2,3=9.5 Hz,1H; GlcA H-2), 5.32 (dd, J_3,4=J_4,5=9.5 Hz,

1H; GlcA H-4),4.98 (dd, J_3,4=2.5 Hz, J_4,5<1 Hz, 1H; GalN H-4), 4.85 (d,

1H; GlcA H-1), 4.82 (ABq, 2H; CH₂Ar), 4.78 (dd, 1H; GlcA H-3), 4.44

(d, J_1,2=8.0 Hz, 1H; GalN H-1), 4.32 (m, 2H; 2GalN H-6), 4.22 (d, 1H;

GlcA H-5), 4.0–3.90 (m, 3H; GalN H-2, H-3, H-5), 3.73 (s, 3H;

COOCH₃), 2.82–2.48 (m, 4H; CH₂CO), 2.09 (s, 3H; COCH₃), 1.28 ppm

J

_3,4=2.5 Hz, J_4,5<1 Hz, 1H; GalN H-4), 4.01 (dd, J_2,3=11.0 Hz, 1H;

GalN H-2), 4.88 (m, 1H; GalN H-5), 3.76 (dd, 1H; GalN H-3), 3.70 (d,

_4,5=9.5 Hz, 1H; GlcA H-5), 3.63 (dd, 1H; GlcA H-4), 3.45 (dd, 1H;

J

GlcA H-2), 1.80 ppm (s, 3H; NHCOCH₃); HRMS: m/z: calcd for

[C₂₅H₂₈NNa₃O₁₈S₂ꢀ2Na+H]^ꢀ: 718.0724; found: 718.0739.

CS-M disaccharide glycoside 50: From ester 47 (127 mg, 0.12 mmol) as

described for the preparation of 19 to give the sodium salt 50 (91 mg,

87%) as a white powder. R_f=0.25 (EtOAc/MeOH/water 4:2:1); [a]_D²²

=

1

ꢀ21 (c=1 in water); H NMR (400 MHz, D₂O, internal HOD, d_H=4.79):

d=8.0–7.40 (m, 7H; arom. H), 4.96 (ABq, 2H; CH₂Ar), 4.78 (dd, J_3,4

=

2.5 Hz, J_4,5<1 Hz, 1H; GalN H-4), 4.56 (d, J_1,2=8.0 Hz, 1H; GalN H-1),

4.47 (d, J_1,2=7.5 Hz, 1H; GlcA H-1), 4.35–2.28 (m, 2H; 2GalN H-6), 4.23

(dd, J_2,3=J_3,4=9.5 Hz, 1H; GlcA H-3), 4.08–4.0 (m, 3H; GalN H-2, H-3,

H-5), 3.66 (dd, J_4,5=9.5 Hz, 1H; GlcA H-4), 3.64 (d, 1H; GlcA H-5),

3.48 (dd, 1H; GlcA H-2), 1.81 ppm (s, 3H; NHCOCH₃); HRMS: m/z:

calcd for [C₂₅H₂₇NNa₄O₂₁S₃ꢀ2Na+H]^ꢀ: 820.0111; found: 801.0128.

CS-K disaccharide 51: From glycoside 48 (50 mg, 64 mmol) as described

for the preparation of 25 to give the target disaccharide 51 (39 mg, 95%)

as a white powder. R_f=0.40 (EtOAc/MeOH/water 3:2:1); [a]²_D²=+2.5

(c=1, equil., in water); ¹H NMR (400 MHz, D₂O, internal HOD, d_H=

4.79): d=5.23 (d, J_1,2=3.5 Hz; GalN H-1a), 4.86, 4.79 (2dd, J_3,4=2.5 Hz,

(s,

3H;

NHCOCH₃);

HRMS:

m/z:

calcd

for

[C₄₅H₄₅NNa₂O₂₂S₂ꢀ2Na+2H]^2ꢀ: 507.5937; found: 507.5952.

Sodium 2-naphthylmethyl O-(sodium methyl 2-O-benzoyl-4-O-levulino-

yl-3-O-sulfonato-b-d-glucopyranosyluronate)-(1!3)-2-acetamido-2-

deoxy-6-O-sulfonato-b-d-galactopyranoside (46): A mixture of triol 44

(106 mg, 140 mmol) and sulfur trioxide/trimethylamine complex (117 mg,

0.84 mmol) in anhydrous DMF (3 mL) was stirred for 24 h at 408C, then

was cooled. Methanol (0.5 mL) was added, and the mixture was concen-

trated. Flash silica chromatography (CH₂Cl₂/MeOH 3:1) followed by elu-

tion from Sephadex SP C-25 [Na⁺] with 9:5:1 CH₂Cl₂/MeOH/water gave

the disulfate 46 (101 mg, 75%) as a white powder. R_f=0.40 (CH₂Cl₂/

J

_4,5<1 Hz, 1H; GalN H-4a,H-4b), 4.72 (d, J_1,2=8.0 Hz; GalN H-1b),

4.61, 4.58 (2d, J_1,2=7.5 Hz, 1H; GlcA H-1a,H-1b),4.35 (dd, J_2,3=11.0 Hz;

GalN H-2a), 4.28 (dd, J_2,3=J_3,4=9.5 Hz, 1H; GlcA H-3), 4.26–4.20 (m,

2H; GalN H-3a, H-5a), 4.10–4.02 (m; GalN H-2b, H-3b), 3.86–377 (m;

GalN H-5b, 2GalN H-6, GlcA H-5), 3.72 (dd, J_4,5=9.5 Hz, 1H; GlcA H-

4), 3.52 (dd, 1H; GlcA H-2), 2.02 ppm (s, 3H; NHCOCH₃); HRMS:

m/z: calcd for [C₁₄H₂₀NNa₃O₁₈S₂ꢀ2Na+H]^ꢀ: 578.0098; found: 578.0106.

CS-L disaccharide 52: From glycoside 49 (50 mg, 65 mmol) as described

for the preparation of 25 to give the target disaccharide 52 (39 mg, 94%)

as a white powder. R_f=0.35 (EtOAc/MeOH/water 3:2:1); [a]²_D²=+1.5

(c=1, equil., in water); ¹H NMR (400 MHz, D₂O, internal HOD, d_H=

4.79): d=5.24 (d, J_1,2=3.5 Hz; GalN H-1a), 4.73 (d, J_1,2=8.0 Hz; GalN

H-1b), 4.67, 4.64 (2d, J_1,2=7.5 Hz, 1H; GlcA H-1a,H-1b), 4.37 (dd, J_2,3=

11.0 Hz; GalN H-2a), 4.29 (dd, J_2,3=J_3,4=9.5 Hz, 1H; GlcA H-3), 4.24

(dd, J_3,4=3.0 Hz, J_4,5<1 Hz, 1H; GalN H-4), 4.22–4.16 (m; GalN H-5a, 2

GalN H-6), 4.07 (dd, J_2,3=11.0 Hz; GalN H-3a), 4.04 (dd; GalN H-2a),

3.96 (m; GalN H-5b), 3.87 (dd; GalN H-3b), 3.78 (d, J_4,5=9.5 Hz, 1H;

GlcA H-5), 3.69 (dd, J_3,4=9.5 Hz, 1H; GlcA H-4), 3.52 (dd, 1H; GlcA

H-2), 2.06 ppm (s, 3H; NHCOCH₃); HRMS: m/z: calcd for

[C₁₄H₂₀NNa₃O₁₈S₂ꢀ2Na+H]^ꢀ: 578.0098; found: 578.0095.

1

MeOH 5:2); [a]²_D²=ꢀ7 (c=1 in methanol); H NMR (400 MHz, CD₃OD/

CDCl₃3:1): d=8.02–7.25 (m, 12H; arom. H), 5.21 (dd, J_1,2=7.5 Hz, J_2,3

=

9.5 Hz,1H; GlcA H-2), 5.14 (dd, J_3,4=J_4,5=9.5 Hz, 1H; GlcA H-4), 4.92

(d, 1H; GlcA H-1), 4.84 (ABq, 2H; CH₂Ar), 4.82 (dd, 1H; GlcA H-3),

4.38 (d, J_1,2=8.0 Hz, 1H; GalN H-1), 4.28 (d, 1H; GlcA H-5), 4.22 (m,

2H; 2GalN H-6); 4.16 (dd, J_3,4=2.5 Hz, J_4,5<1 Hz, 1H; GalN H-4), 4.04

(dd, J_2,3=11.0 Hz, 1H; GalN H-2), 4.78 (m, 1H; GalN H-5), 4.75 (s, 3H;

COOCH₃), 3.71 (dd, 1H; GalN H-3), 2.80–2.44 (m, 4H; CH₂CO), 2.11 (s,

3H; COCH₃), 1.08 ppm (s, 3H; NHCOCH₃); HRMS: m/z: calcd for

[C₃₈H₄₁NNa₂O₂₁S₂ꢀ2Na+2H]^2ꢀ: 455.5806; found: 455.5798.

Disodium 2-naphthylmethyl O-(sodium methyl 2-O-benzoyl-4-O-levuli-

noyl-3-O-sulfonato-b-d-glucopyranosyluronate)-(1!3)-2-acetamido-2-

deoxy-4,6-di-O-sulfonato-b-d-galactopyranoside (47): From triol 44

(83 mg, 110 mmol) as described for the preparation of 13 to give the tri-

sulfate 47 (112 mg, 90%) as a white powder. R_f=0.20 (CH₂Cl₂/MeOH

1

2:1); [a]²_D²=+5 (c=1 in water); H NMR (400 MHz, D₂O, internal HOD,

d_H=4.79): d=8.0–7.35 (m, 12H; arom. H), 5.29 (dd, J_3,4=J_4,5=9.5 Hz,

1H; GlcA H-4), 5.21 (dd, J_1,2=7.5 Hz, J_2,3=9.5 Hz,1H; GlcA H-2), 4.96

(d, 1H; GlcA H-1), 4.92 (dd, J_3,4=2.5 Hz, J_4,5<1 Hz, 1H; GalN H-4),

4.86 (ABq, 2H; CH₂Ar), 4.83 (dd, 1H; GlcA H-3), 4.48 (d, J_1,2=8.0 Hz,

1H; GalN H-1), 4.35 (d, 1H; GlcA H-5), 4.28 (m, 2H; 2GalN H-6), 3.99

(m, 1H; GalN H-5), 3.91–3.86 (m, 2H; GalN H-2, H-3), 3.68 (s, 3H;

COOCH₃), 2.80–2.48 (m, 4H; CH₂CO), 2.21 (s, 3H; COCH₃), 1.11 ppm

CS-M disaccharide 53: From glycoside 50 (61 mg, 70 mmol) as described

for the preparation of 25 to give the target disaccharide 53 (48 mg, 95%)

as a white powder. R_f=0.30 (EtOAc/MeOH/water 3:2:1); [a]²_D²=+11

(c=1, equil., in water); ¹H NMR (400 MHz, D₂O, internal HOD, d_H=

4.79): d=5.26 (d, J_1,2=3.5 Hz; GalN H-1a), 4.92, 4.85 (2d, J_3,4=2.5 Hz,

J

_4,5<1 Hz, 1H; GalN H-4a,H-4b), 4.77 (d, J_1,2=8.0 Hz; GalN H-1b),

4.64, 4.60 (2d, J_1,2=7.5 Hz, 1H; GlcA H-1a,H-1b), 4.53 (dd, J_2,3=11.0 Hz;

GalN H-3a), 4.38 (dd; GalN H-2a), 4.28 (dd, J_2,3=J_3,4=9.5 Hz, 1H;

GlcA H-3), 4.25–4.18 (m, 2H; 2GalN H-6), 4.12–4.08 (m; GalN H-2b, H-

3b), 3.78–3.71 (m; GalN H-5b; GlcA H-4, H-5), 3.54 (dd, 1H; GlcA H-

2), 2.06 ppm (s, 3H; NHCOCH₃); HRMS: m/z: calcd for

[C₁₄H₁₉NNa₄O₂₁S₃ꢀ2Na+H]^ꢀ: 679.9485; found: 679.9489.

(s,

3H;

NHCOCH₃);

HRMS:

m/z:

calcd

for

[C₃₈H₄₀NNa₃O₂₄S₃ꢀ2Na+2H]^2ꢀ: 506.6028; found: 506.6021.

CS-K disaccharide glycoside 48: From ester 45 (106 mg, 0.1 mmol) as de-

scribed for the preparation of 19 to give the sodium salt 48 (67 mg, 88%)

as a white powder. R_f=0.40 (EtOAc/MeOH/water 4:2:1); [a]²_D²=ꢀ28

(c=1 in water); ¹H NMR (400 MHz, D₂O, internal HOD, d_H=4.79): d=

2-Naphthylmethyl O-(methyl 2-O-benzoyl-3-O-chloroacetyl-4-O-levuli-

noyl-b-d-glucopyranosyluronate)-(1!3)-2-deoxy-2-trichloracetamido-b-

d-galactopyranoside (54)

8.0–7.40 (m, 7H; arom. H), 4.95 (ABq, 2H; CH₂Ar), 4.78 (dd, J_3,4

=

2.5 Hz, J_4,5<1 Hz, 1H; GalN H-4), 4.61 (d, J_1,2=8.0 Hz, 1H; GalN H-1),

4.48 (d, J_1,2=7.5 Hz, 1H; GlcA H-1), 4.24 (dd, J_2,3=J_3,4=9.5 Hz, 1H;

GlcA H-3), 4.08–4.0 (m, 2H; GalN H-2, H-3), 3.90–3.80 (m, 3H; GalN

H-5, 2GalN H-6), 3.70 (dd, J_4,5=9.5 Hz, 1H; GlcA H-4), 3.68 (d, 1H;

Method a (Scheme 6): From alcohol 4 (1.89 g, 2 mmol) as described for

the preparation of 31 followed by crystallization from MeOH to give the

9592

www.chemeurj.org

ꢁ 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Chem. Eur. J. 2009, 15, 9579 – 9595

Stereocontrolled Construction of Size-Defined Oligomers

FULL PAPER

diol 54 (1.528 g, 82% from 4). R_f=0.35 (CH₂Cl₂/MeOH 12:1); m.p. 218–

2198C; [a]²_D²=ꢀ4 (c=1 in methanol); ¹H NMR (400 MHz, CD₃OD/

CDCl₃3:1): d=7.95–7.32 (m, 12H; arom. H), 5.48 (dd, J_2,3=J_3,4=9.5 Hz,

2-Naphthylmethyl O-(methyl 2-O-benzoyl-3-O-chloroacetyl-4-O-levuli-

noyl-b-d-glucopyranosyluronate)-(1!3)-6-O-benzoyl-4-O-chloroacetyl-2-

deoxy-2-trichloroacetamido-b-d-galactopyranoside (57): From alcohol 55

(520 mg, 0.5 mmol) as described for the preparation of 5 to give the ester

57 (513 mg, 92%). R_f=0.40 (CH₂Cl₂/acetone 15:1); m.p. 232–2348C

(from MeOH); [a]²_D²=ꢀ1.5 (c=1 in chloroform); ¹H NMR (400 MHz,

CDCl₃): d=8.10–7.30 (m, 17H; arom. H), 6.69 (d, J=7.0 Hz, 1H; GalN

1H; GlcA H-3), 5.28 (dd, J_1,2=7.5 Hz, 1H; GlcA H-2), 5.26 (dd, J_4,5

=

9.5 Hz, 1H; GlcA H-4), 4.97 (d, 1H; GlcA H-1), 4.87 (ABq, 2H;

CH₂Ar), 4.76 (d, J_1,2=8.0 Hz, 1H; GalN H-1), 4.25 (d, 1H; GlcA H-5),

4.23 (dd, J_2,3=11.0 Hz, J_3,4=3.5 Hz, 1H; GalN H-3), 4.16 (dd, J_4,5<1 Hz,

1H; GalN H-4), 4.04 (ABq, 2H; COCH₂Cl), 3.95 (dd, 1H; GalN H-2),

3.90–3.80 (m, 2H; 2GalN H-6), 3.75 (s, 3H; COOCH₃), 3.55 (m, 1H;

GalN H-5), 2.80–2.45 (m, 4H; CH₂CO), 2.10 ppm (s, 3H; COCH₃); MS:

m/z: 954 [M+Na]⁺for ³⁵Cl; elemental analysis calcd (%) for

C₄₀H₄₁Cl₄NO₁₆: C 51.46, H 4.43, N 1.50; found: C 51.30, H 4.32, N 1.40.

NH), 5.67 (dd, J_3,4=3.5 Hz, J_4,5<1 Hz, 1H; GalN H-4), 5.38 (dd, J_2,3

=

J

_3,4=9.5 Hz, 1H; GlcA H-3), 5.32 (dd, J_4,5=9.5 Hz, 1H; GlcA H-4), 5.18

(dd, J_1,2=7.5 Hz, 1H; GlcA H-2), 5.04 (d, J_1,2=8.0 Hz, 1H; GalN H-1),

4.86 (ABq, 2H; CH₂Ar), 4.78 (dd, J_2,3=11.0 Hz, 1H; GalN H-3), 4.75 (d,

1H; GlcA H-1), 4.50–4.40 (m, 2H; 2GalN H-6), 4.25, 4.0 (2ABq, 4H;

2COCH₂Cl), 4.04 (m, 2H; GalN H-5, GlcA H-5), 3.68 (s, 3H;

COOCH₃), 3.53 (m, 1H; GalN H-2), 2.80–2.37 (m, 4H; CH₂CO),

2.06 ppm (s, 3H; COCH₃); elemental analysis calcd (%) for

C₄₉H₄₆Cl₅NO₁₈: C 52.82, H 4.16, N 1.26; found: C 52.71, H 4.21, N 1.17.

Method

b (Scheme 6): Chloroacetyl chloride (208 mL, 2.6 mmol) was

added dropwise at 08C to a solution of imidazole (353 mg, 5.2 mmol) in

1,2-dichloroethane (8 mL), and the mixture was stirred for 15 min. The

salts were filtered off, and the filtrate was added to a suspension of diol 1

(1.68 g, 2 mmol) in 1,2-dichloroethane (20 mL). The mixture was stirred

for 30 min at 508C, then was cooled, diluted with CH₂Cl₂(50 mL),

washed with cold 5% hydrochloric acid, saturated aqueous NaHCO₃and

water, dried (MgSO₄), and concentrated. Flash silica chromatography

(CH₂Cl₂/acetone 10:1) gave the intermediate 3-chloroacetate (1.29 g,

2-Naphthylmethyl O-(methyl 2-O-benzoyl-3-O-chloroacetyl-4-O-levuli-

noyl-b-d-glucopyranosyluronate)-(1!3)-4-O-benzoyl-6-O-chloroacetyl-2-

deoxy-2-trichloroacetamido-b-d-galactopyranoside (58): From alcohol 56

(480 mg, 0.46 mmol) as described for the preparation of 5 to give the

ester 58 (477 mg, 93%) as a white foam. R_f=0.40 (CH₂Cl₂/acetone 14:1);

[a]²_D²=+22 (c=1 in chloroform); ¹H NMR (400 MHz, CDCl₃): d=8.05–

7.32 (m, 17H; arom. H), 6.82 (d, J=7.0 Hz, 1H; GalN NH), 5.72 (dd,

71%) as

a

white solid. M.p. 185–1868C (from EtOH); ¹H NMR

(400 MHz, CDCl₃): d=7.95–7.32 (m, 12H; arom. H), 7.07 (d, J=7.5 Hz,

1H; GalN NH), 5.58 (s, 1H; PhCH), 5.12 (d, J_1,2=8.0 Hz, 1H; GalN H-

J

_3,4=3.5 Hz, J_4,5<1 Hz, 1H; GalN H-4), 5.37 (dd, J_2,3=J_3,4=9.5 Hz, 1H;

GlcA H-3), 5.30 (dd, J_4,5=9.5 Hz, 1H; GlcA H-4), 5.16 (dd, J_1,2=7.5 Hz,

1H; GlcA H-2), 5.12 (d, J_1,2=8.0 Hz, 1H; GalN H-1), 4.85 (ABq, 2H;

CH₂Ar), 4.84 (d, 1H; GlcA H-1), 4.81 (dd, J_2,3=11.0 Hz, 1H; GalN H-3),

4.40–4.32 (m, 2H; 2GalN H-6), 4.10–4.0 (m, 4H; GalN H-5, GlcA H-5,

COCH₂Cl), 3.90 (ABq, 2H; COCH₂Cl), 3.76 (m, 1H; GalN H-2), 3.75 (s,

3H; COOCH₃), 2.78–2.35 (m, 4H; CH₂CO), 2.08 ppm (s, 3H; COCH₃);

elemental analysis calcd (%) for C₄₉H₄₆Cl₅NO₁₈: C 52.82, H 4.16, N 1.26;

found: C 52.60, H 4.07, N 1.15.

1), 5.09 (m, 2H; GlcA H-3, H-4), 4.84 (ABq, 2H; CH₂Ar), 4.57 (d, J_1,2

=

7.5 Hz, 1H; GlcA H-1), 4.55 (dd, J_2,3=11.0 Hz, J_3,4=3.5 Hz, 1H; GalN

H-3), 4.38 (dd, J_4,5<1 Hz, 1H; GalN H-4), 4.12–4.0 (m, 4H; 2GalN H-6,

COCH₂Cl), 3.96 (dd, 1H; GalN H-2), 3.93 (d, J_4,5=9.5 Hz, 1H; GlcA H-

5), 3.75 (s, 3H; COOCH₃), 3.65 (m, 1H; GlcA H-2), 3.51 (m, 1H; GalN

H-5), 2.82 (d,

J_2,OH=3.5 Hz, 1H; GlcA HO-2), 2.76–2.35 (m, 4H;

CH₂CO), 2.07 ppm (s, 3H; COCH₃). The intermediate was then benzoy-

lated and hydrolyzed as described for the preparation of 31 to give the

diol 54 (1.12 g, 60% from 1). M.p. 217–2188C.

2-Naphthylmethyl O-(methyl 2-O-benzoyl-3-O-chloroacetyl-b-d-gluco-

pyranosyluronate)-(1!3)-6-O-benzoyl-4-O-chloroacetyl-2-deoxy-2-tri-

chloroacetamido-b-d-galactopyranoside (59): From ester 57 (167 mg,

0.15 mmol) as described for the preparation of 6 to give the alcohol 59

(132 mg, 87%). R_f=0.40 (CH₂Cl₂/acetone 12:1); m.p. 224–2268C (from

EtOAc/petroleum ether); [a]²_D²=ꢀ20 (c=1 in chloroform); ¹H NMR

(400 MHz, CDCl₃): d=8.10–7.30 (m, 17H; arom. H), 6.68 (d, J=7.0 Hz,

1H; GalN NH), 5.68 (dd, J_3,4=3.5 Hz, J_4,5<1 Hz, 1H; GalN H-4), 5.27

(dd, J_2,3=J_3,4=9.5 Hz, 1H; GlcA H-3), 5.12 (dd, J_1,2=7.5 Hz, 1H; GlcA

H-2), 5.08 (d, J_1,2=8.0 Hz, 1H; GalN H-1), 4.86 (ABq, 2H; CH₂Ar), 4.80

(dd, J_2,3=11.0 Hz, 1H; GalN H-3), 4.74 (d, 1H; GlcA H-1), 4.50–4.40 (m,

2-Naphthylmethyl O-(methyl 2-O-benzoyl-3-O-chloroacetyl-4-O-levuli-

noyl-b-d-glucopyranosyluronate)-(1!3)-6-O-benzoyl- (55) and 4-O-ben-

zoyl-2-deoxy-2-trichloroacetamido-b-d-galactopyranoside (56): Trimethyl

orthobenzoate (1.77 mL, 10 mmol) was added to a suspension of diol 54

(1.16 g, 1.24 mmol) and CSA (125 mg) in anhydrous toluene (10 mL) and

CH₂Cl₂(15 mL), and the mixture was stirred for 45 min. Triethyl amine

(0.4 mL) was then added, and the mixture was diluted with CH₂Cl₂

(50 mL), washed with saturated aqueous NaHCO₃and water, dried

(MgSO₄) and concentrated. A solution of the residue in 80% AcOH

(50 mL) was stirred for 15 min at RT, then was concentrated. Flash silica

chromatography (CH₂Cl₂/acetone 10:1) gave first the 6-benzoate 55

(605 mg, 47%). M.p. 230–2328C (from MeOH); [a]²_D²=ꢀ1 (c=1 in

chloroform); ¹H NMR (400 MHz, CDCl₃): d=8.10–7.30 (m, 17H; arom.

H), 6.84 (d, J=7.5 Hz, 1H; GalN NH), 5.44 (dd, J_2,3=J_3,4=9.5 Hz, 1H;

GlcA H-3), 5.37 (m, 2H; GlcA H-2, H-4), 5.02 (d, J_1,2=8.0 Hz, 1H;

2H; 2GalN H-6), 4.27, 3.94 (2ABq, 2H; 2COCH₂Cl), 4.05 (dd, J_2,3

=

11.0 Hz, 1H; GalN H-3), 4.0 (m, 1H; GlcA H-4), 3.92 (d, J_4,5=9.5 Hz,

1H; GlcA H-5), 3.68 (s, 3H; COOCH₃), 3.51 (m, 1H; GalN H-2),

3.18 ppm (d, J_4,OH=3.0 Hz, 1H; GlcA HO-4); elemental analysis calcd

(%) for C₄₄H₄₀Cl₅NO₁₆: C 52.01, H 3.97, N 1.38; found: C 52.10, H 3.82,

N 1.20.

GalN H-1), 4.92 (d,

J_1,2=7.5 Hz, 1H; GlcA H-1), 4.86 (ABq, 2H;

O-(Methyl 2-O-benzoyl-3-O-chloroacetyl-4-O-levulinoyl-b-d-glucopyra-

nosyluronate)-(1!3)-6-O-benzoyl-4-O-chloroacetyl-2-deoxy-2-trichloro-

CH₂Ar), 4.65 (m, 2H; 2GalN H-6), 4.60 (dd, J_2,3=11.0 Hz, J_3,4=3.5 Hz,

1H; GalN H-3), 4.26 (m, 1H; GalN H-4), 4.18 (d, J_4,5=9.5 Hz, 1H; GlcA

H-5), 4.06 (ABq, 2H; COCH₂Cl), 3.91 (m, 1H; GalN H-5), 3.75 (s, 3H;

COOCH₃), 3.64 (m, 1H; GalN H-2), 2.95 (d, J_2,OH=2.0 Hz, 1H; GalN

HO-4), 2.80–2.38 (m, 4H; CH₂CO), 2.07 ppm (s, 3H; COCH₃); elemental

analysis calcd (%) for C₄₇H₄₅Cl₄NO₁₇: C 54.40, H 4.37, N 1.35; found: C

54.32, H 4.41, N 1.29. Next eluted was the 4-benzoate 56 (553 mg, 43%)

as a white foam. [a]²_D²=+21 (c=1 in chloroform); ¹H NMR (400 MHz,

CDCl₃): d=8.10–7.30 (m, 17H; arom. H), 6.83 (d, J=7.5 Hz, 1H; GalN

AHCTUNGTERGaNNUN cetimido-1-O-trichloroacetimidoyl-a-d-galactopyranose (60): From gly-

coside 57 (357 mg, 0.32 mmol) as described for the preparation of 7 to

give the imidate 60 (240 mg, 67%) as a white foam. R_f=0.40 (EtOAc/pe-

troleum ether 1:1); [a]_D²²=+79 (c=1 in chloroform); ¹H NMR

(400 MHz, CDCl₃): d=8.72 (s, 1H; C=NH), 8.05–7.40 (m, 10H; arom.

H), 6.69 (d, J=8.0 Hz, 1H; GalN NH), 6.51 (d, J_1,2=3.5 Hz, 1H; GalN

H-1), 5.76 (dd, J_3,4=3.5 Hz, J_4,5<1 Hz, 1H; GalN H-4), 5.46 (dd, J_2,3

=

J

_3,4=9.5 Hz, 1H; GlcA H-3), 5.32 (dd, J_4,5=9.5 Hz, 1H; GlcA H-4), 5.27

NH), 5.66 (dd, J_3,4=3.5 Hz, J_4,5<1 Hz, 1H; GalN H-4), 5.38 (dd, J_2,3

_3,4=9.5 Hz, 1H; GlcA H-3), 5.24 (dd, J_4,5=9.5 Hz, 1H; GlcA H-4), 5.18

(dd, J_1,2=7.5 Hz, 1H; GlcA H-2), 5.14 (d, 1H; GlcA H-1), 4.87 (ABq,

2H; CH₂Ar), 4.86 (d, J_1,2=8.0 Hz, 1H; GalN H-1), 4.83 (dd, J_2,3

=

(dd, J_1,2=7.5 Hz, 1H; GlcA H-2), 4.97 (d, 1H; GlcA H-1), 4.63 (m, J_2,3

=

J

11.0 Hz, 1H; GalN H-2), 4.48 (m, 1H; GalN H-5), 4.38 (m, 2H; 2GalN

H-6), 4.32 (dd, 1H; GalN H-3), 4.24, 4.04 (2ABq, 2H; 2COCH₂Cl), 4.12

(d, 1H; GlcA H-5), 3.74 (s, 3H; COOCH₃),), 2.80–2.38 (m, 4H;

CH₂CO), 2.12 ppm (s, 3H; COCH₃); elemental analysis calcd (%) for

C₄₀H₃₈Cl₈N₂O₁₈: C 42.96, H 3.43, N 2.50; found: C 42.71, H 3.28, N 2.39.

=

11.0 Hz, 1H; GalN H-3), 4.08 (d, 1H; GlcA H-5), 3.92 (ABq, 2H;

COCH₂Cl), 3.86–3.75 (m, 2H; GalN H-2, H-6), 3.74 (s, 3H; COOCH₃),

3.54 (m, 1H; GalN H-6), 3.34 (dd, J=4.0 and 9.5 Hz, 1H; GalN HO-6);

2.78–2.35 (m, 4H; CH₂CO), 2.08 ppm (s, 3H; COCH₃); elemental analy-

sis calcd (%) for C₄₇H₄₅Cl₄NO₁₇: C 54.40, H 4.37, N 1.35; found: C 54.20,

H 4.21, N 1.26.

2-Naphthylmethyl O-(methyl 2-O-benzoyl-3-O-chloroacetyl-b-d-gluco-

pyranosyluronate)-(1!3)-4-O-benzoyl-6-O-chloroacetyl-2-deoxy-2-tri-

chloroacetamido-b-d-galactopyranoside (61): From ester 58 (142 mg,

Chem. Eur. J. 2009, 15, 9579 – 9595

ꢁ 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

www.chemeurj.org

9593

J.-C. Jacquinet et al.

127 mmol) as described for the preparation of 6 to give the alcohol 61

(103 mg, 80%). R_f=0.40 (EtOAc/petroleum ether 4:3); m.p. 184–1858C

(from EtOAc/petroleum ether); [a]²_D²=+7 (c=1 in chloroform);

¹H NMR (400 MHz, CDCl₃): d=8.05–7.35 (m, 17H; arom. H), 6.79 (d,

J=7.0 Hz, 1H; GalN NH), 5.72 (dd, J_3,4=3.5 Hz, J_4,5<1 Hz, 1H; GalN

H-4), 5.22 (dd, J_2,3=J_3,4=9.5 Hz, 1H; GlcA H-3), 5.14 (d, J_1,2=8.0 Hz,

1H; GalN H-1), 5.04 (dd, J_1,2=7.5 Hz, 1H; GlcA H-2), 4.88 (ABq, 2H;

CH₂Ar), 4.84 (dd, J_2,3=11.0 Hz, 1H; GalN H-3), 4.80 (d, 1H; GlcA H-1),

4.40–4.30 (m, 2H; 2GalN H-6), 4.03 (m, 1H; GalN H-5), 4.0 (s, 2H;

COCH₂Cl), 3.95 (m, 2H; GlcA H-4, H-5), 3.84 (ABq, 2H; COCH₂Cl),

[M+Na]⁺for ³⁵Cl. The tetrol (85 mg, 51 mmol) was reduced as described

for the preparation of 11. Flash silica chromatography (CH₂Cl₂/MeOH

12:1) gave the acetamide 65 (60 mg, 69% from 63). M.p. 238–2408C

(from MeOH); [a]²_D²=ꢀ4 (c=0.5 in methanol); ¹H NMR (400 MHz,

CD₃OD/CDCl₃3:1): d=8.05–7.20 (m, 27H; arom. H), 5.15 (dd, J_1,2

=

7.5 Hz, J_2,3=9.5 Hz, 1H; GlcA^IH-2), 5.12 (dd, J_1,2=7.5 Hz, J_2,3=9.5 Hz,

1H; GlcA^IIH-2), 5.04 (dd, J_3,4=J_4,5=9.5 Hz, 1H; GlcA^IIH-4), 4.88, 4.72

(2d, J_1,2=8.0 Hz, 2H; 2GalN H-1), 4.85 (ABq, 2H; CH₂Ar), 4.83 (d, 1H;

GlcA^IH-1), 4.78 (d, 1H; GlcA^IIH-1), 4.65, 4.42 (2m, 4H; 4GalN H-6),

4.18, 4.12 (2dd, J_3,4=3.5 Hz, J_4,5<1 Hz, 2H; 2GalN H-4), 4.15 (m, 3H; 2

GalN H-3, GlcA^IIH-5), 4.04–3.98 (m, 2H; 2GalN H-2), 3.96 (dd, J_3,4

_4,5=9.5 Hz, 1H; GlcA^IH-4), 3.94 (d, 1H; GlcA^IH-5), 3.78–3.74 (m,

=

3.80 (s, 3H; COOCH₃), 3.68 (m, 1H; GalN H-2), 3.12 ppm (d, J_4,OH

=

3.0 Hz, 1H; GlcA HO-4); elemental analysis calcd (%) for

C₄₄H₄₀Cl₅NO₁₆: C 52.01, H 3.97, N 1.38; found: C 51.92, H 4.02, N 1.29.

J

2H; 2GalN H-5), 3.73, 3.58 (2s, 6H; 2COOCH₃), 2.80–2.45 (m, 4H;

CH₂CO), 2.17 (s, 3H; COCH₃), 1.32, 1.28 ppm (2s, 6H; 2NHCOCH₃);

MS: m/z: 1459.4 [M]^ꢀ; elemental analysis calcd (%) for C₇₄H₇₈N₂O₂₉: C

60.90, H 5.39, N 1.92; found: C 60.71, H 5.21, N 1.70.

O-(Methyl 2-O-benzoyl-3-O-chloroacetyl-4-O-levulinoyl-b-d-glucopyra-

nosyluronate)-(1!3)-4-O-benzoyl-6-O-chloroacetyl-2-deoxy-2-trichloro-

acetimido-1-O-trichloroacetimidoyl-a-d-galactopyranose (62): From gly-

coside 58 (290 mg, 0.26 mmol) as described for the preparation of 7 to

give the imidate 62 (198 mg, 68%). R_f=0.35(EtOAc/petroleum ether

1:1); m.p. 150–1518C (from EtOAc/petroleum ether); [a]²_D²=+88 (c=1

in chloroform); ¹H NMR (400 MHz, CDCl₃): d=8.74 (s, 1H; C=NH),

8.0–7.40 (m, 10H; arom. H), 6.86 (d, J=7.5 Hz, 1H; GalN NH), 6.64 (d,

CS-L tetrasaccharide acetamide 66: From ester 64 (111 mg, 56 mmol) as

described for the preparation of 11. Flash silica chromatography

(CH₂Cl₂/MeOH 15:1) gave the intermediate tetrol (84 mg, 90%) as a

white foam. [a]²_D²=+13 (c=1 in methanol); MS: m/z: 1686 [M+Na]⁺for

³⁵Cl. The tetrol (82 mg, 49 mmol) was reduced as described for the prepa-

ration of 11. Flash silica chromatography (CH₂Cl₂/MeOH 12:1) gave the

acetamide 66 (56 mg, 69% from 64). M.p. 210–2128C (from EtOH);

[a]²_D²=+7 (c=0.5 in methanol); ¹H NMR (400 MHz, CD₃OD/CDCl₃

J

_1,2=3.5 Hz, 1H; GalN H-1), 5.82 (dd, J_3,4=3.5 Hz, J_4,5<1 Hz, 1H; GalN

H-4), 5.44 (dd, J_2,3=J_3,4=9.5 Hz, 1H; GlcA H-3), 5.27 (dd, J_1,2=7.5 Hz,

1H; GlcA H-2), 5.23 (dd, J_4,5=9.5 Hz, 1H; GlcA H-4), 5.03 (d, 1H;

GlcA H-1), 4.75 (m, J_2,3=11.0 Hz, 1H; GalN H-2), 4.50 (dd, 1H; GalN

H-3), 4.47 (m, 1H; GalN H-5), 4.30–4.20 (m, 2H; 2GalN H-6), 4.12 (d,

1H; GlcA H-5), 4.04, 3.98 (2s, 4H; 2COCH₂Cl), 3.64 (s, 3H; COOCH₃),

2.80–2.40 (m, 4H; CH₂CO), 2.10 ppm (s, 3H; COCH₃); elemental analy-

sis calcd (%) for C₄₀H₃₈Cl₈N₂O₁₈: C 42.96, H 3.43, N 2.50; found: C 42.81,

H 3.39, N 2.40.

3:1): d=8.10–7.30 (m, 27H; arom. H), 5.55, 5.50 (2dd, J_3,4=3.0 Hz, J_4,5

<

1 Hz, 2H; 2GalN H-4), 5.0 (dd, J_1,2=7.5 Hz, J_2,3=9.5 Hz, 1H; GlcA^IIH-

2), 4.96 (dd, J_3,4=J_4,5=9.5 Hz, 1H; GlcA^IIH-4), 4.93 (dd, J_1,2=7.5 Hz,

J

_2,3=9.5 Hz, 1H; GlcA^IH-2), 4.86 (ABq, 2H; CH₂Ar), 4.83 (d, 1H;

GlcA^IH-1), 4.78 (d, 1H; GlcA^IIH-1), 4.68, 4.54 (2d, J_1,2=8.0 Hz, 2H;

2GalN H-1), 4.22, 4.18 (2dd, J_2,3=11.0 Hz, 2H; 2GalN H-3), 4.04 (d, 1H;

GlcA^IIH-5), 3.98–3.93 (m, 2H; 2GalN H-2), 3.88 (dd, J_3,4=J_4,5=9.5 Hz,

1H; GlcA^IH-4), 3.83 (dd, 1H; GlcA^IIH-3), 3.78 (m, 2H; GlcA^IH-3, H-

5), 3.75–3.70 (m, 2H; 2GalN H-5), 3.74, 3.66 (2s, 6H; 2COOCH₃), 3.62–

3.55 (m, 4H; 4GalN H-6), 2.78–2.42 (m, 4H; CH₂CO), 2.16 (s, 3H;

COCH₃), 1.37, 1.18 ppm (2s, 6H; 2NHCOCH₃); MS: m/z: 1459.4 [M]^ꢀ;

elemental analysis calcd (%) for C₇₄H₇₈N₂O₂₉: C 60.90, H 5.39, N 1.92;

found: C 60.75, H 5.29, N 1.74.

CS-K tetrasaccharide 63: From alcohol 59 (102 mg, 0.1 mmol) and imi-

date 60 (145 mg, 0.13 mmol) as described for the preparation of 8 to give

the tetrasaccharide 63 (128 mg, 65%). R_f=0.35 (CH₂Cl₂/acetone 14:1);

1

m.p. 172–1748C (from EtOH); [a]²_D²=+2 (c=1 in chloroform); H NMR

(400 MHz, CDCl₃): d=8.05–7.25 (m, 27H; arom. H), 6.74, 6.67 (2d, J=

7.5 Hz, 2H; 2GalN NH), 5.63, 5.57 (2dd, J_3,4=3.5 Hz, J_4,5<1 Hz, 2H;

2GalN H-4), 5.38 (dd, J_2,3=J_3,4=9.5 Hz, 1H; GlcA^IIH-3), 5.34 (dd, J_4,5

=

9.5 Hz, 1H; GlcA^IIH-4), 5.24 (dd, J_2,3=J_3,4=9.5 Hz, 1H; GlcA^IH-3),

5.16 (dd, J_1,2=7.5 Hz, 1H; GlcA^IIH-2), 5.07, 5.04 (2d, J_1,2=8.0 Hz, 2H;

2GalN H-1), 5.02 (dd, J_1,2=7.5 Hz, 1H; GlcA^IH-2), 4.86 (ABq, 2H;

CH₂Ar), 4.74 (d, 1H; GlcA^IH-1), 4.70 (d, 1H; GlcA^IIH-1), 4.68, 4.64

(2dd, J_2,3=11.0 Hz, 2H; 2GalN H-3), 4.50–4.35 (m, 4H; 4GalN H-6),

4.20–3.95 (4ABq, 8H; 4COCH₂Cl), 4.12 (dd, 1H; GlcA^IH-4), 4.05, 4.04

(2d, 2H; 2GlcA H-5), 4.0–3.93 (m, 2H; 2GalN H-5), 3.67, 3.64 (2s, 6H;

2COOCH₃), 3.48 (m, 2H; 2GalN H-2), 2.78–2.42 (m, 4H; CH₂CO),

2.12 ppm (s, 3H; COCH₃); elemental analysis calcd (%) for

C₈₂H₇₆Cl₁₀N₂O₃₃: C 49.94, H 3.88, N 1.42; found: C 49.81, H 3.93, N 1.31.

CS-K tetrasulfate 67: From tetrol 65 (55 mg, 37 mmol) as described for

the preparation of 11 to give the tetrasulfate 67 (62 mg, 90%) as a white

powder. R_f=0.25 (CH₂Cl₂/MeOH 5:2); [a]²_D²=+13 (c=1 in methanol);

¹H NMR (400 MHz, CD₃OD/CDCl₃3:1): d=8.05–7.20 (m, 27H; arom.

H), 5.43 (dd, J_1,2=2.0 Hz, J_2,3=6.5 Hz, 1H; GlcA^IH-2), 5.34 (m, 2H;

GlcA^IIH-2, H-4), 4.98, 4.92 (2dd, J_3,4=2.0 Hz, J_4,5<1 Hz, 2H; 2GalN H-

4), 4.95 (d, J_1,2=7.5 Hz, 1H; GlcA^IIH-1), 4.93 (d, 1H; GlcA^IH-1), 4.85

(dd, J_2,3=J_3,4=9.5 Hz, 1H; GlcA^IIH-3), 4.80 (ABq, 2H; CH₂Ar), 4.76

(dd, J_3,4=2.0 Hz, 1H; GlcA^IH-3), 4.70–4.60 (m, 2H; 2GalN H-6), 4.58–

4.52 (m, 3H; GalN H-1, H-6, GlcA^IH-4), 4.37 (d, J_4,5=3.0 Hz, 1H;

GlcA^IH-5), 4.32 (d, J_1,2=8.0 Hz, 1H; GalN H-1), 4.28–4.23 (m, 2H;

GalN H-6, GlcA^IIH-5), 4.12–4.07 (m, 2H; 2GalN H-2), 3.95–3.85 (m,

CS-L tetrasaccharide 64: From alcohol 61 (102 mg, 0.1 mmol) and imi-

date 62 (145 mg, 0.13 mmol) as described for the preparation of 8 to give

the tetrasaccharide 64 (122 mg, 62%) as a white foam. R_f=0.35 (EtOAc/

petroleum ether 4:3); [a]²_D²=+16 (c=1 in chloroform); ¹H NMR

(400 MHz, CDCl₃): d=8.05–7.30 (m, 27H; arom. H), 6.78, 6.69 (2d, J=

7.5 Hz, 2H; 2GalN NH), 5.63, 5.61 (2dd, J_3,4=3.5 Hz, J_4,5<1 Hz, 2H;

3H; GalN H-3, 2 H-5), 3.72, 3.70 (2s, 6H; 2COOCH₃), 3.67 (dd, J_2,3

=

11.0 Hz, 1H; GalN H-3), 2.82–2.44 (m, 4H; CH₂CO), 2.15 (s, 3H;

COCH₃), 1.34, 1.26 ppm (2s, 6H; 2NHCOCH₃); HRMS: m/z: calcd for

[C₇₄H₇₄N₂Na₄O₄₁S₄ꢀ4Na+4H]^2ꢀ: 888.1403; found: 888.1386.

2GalN H-4), 5.34 (dd, J_2,3=J_3,4=9.5 Hz, 1H; GlcA^IIH-3), 5.28 (dd, J_4,5

=

9.5 Hz, 1H; GlcA^IIH-4), 5.21 (dd, J_2,3=J_3,4=9.5 Hz, 1H; GlcA^IH-3),

5.12, 5.10 (2d, J_1,2=8.0 Hz, 2H; 2GalN H-1), 5.09 (dd, J_1,2=7.5 Hz, 1H;

GlcA^IIH-2), 5.02 (dd, J_1,2=7.5 Hz, 1H; GlcA^IH-2), 4.85 (ABq, 2H;

CH₂Ar), 4.81, 4.80 (2d, 2H; 2GlcA H-1), 4.78, 4.69 (2dd, J_2,3=11.0 Hz,

2H; 2GalN H-3), 4.20–4.08 (m, 4H; 4GalN H-6), 4.14 (dd, 1H; GlcA^IH-

4), 4.05, 4.04 (2d, 2H; 2GlcA H-5), 4.02–3.75 (m, 8H; 4COCH₂Cl),3.80,

3.72 (2s, 6H; 2COOCH₃), 3.68, 3.58 (2m, 2H; 2GalN H-2), 2.80–2.40 (m,

4H; CH₂CO), 2.14 ppm (s, 3H; COCH₃); elemental analysis calcd (%)

for C₈₂H₇₆Cl₁₀N₂O₃₃: C 49.94, H 3.88, N 1.42; found: C 49.75, H 3.60, N

1.30.

CS-L tetrasulfate 68: From tetrol 66 (50 mg, 34 mmol) as described for

the preparation of 11 to give the tetrasulfate 68 (57 mg, 89%) as a white

powder. R_f=0.30 (CH₂Cl₂/MeOH 5:2); [a]²_D²=+4 (c=1 in methanol);

¹H NMR (400 MHz, CD₃OD/CDCl₃3:1): d=8.05–7.0 (m, 27H; arom.

H), 5.68, 5.53 (2dd, J_3,4=3.0 Hz, J_4,5<1 Hz, 2H; 2GalN H-4), 5.08 (dd,

J

_1,2=7.5 Hz, J_2,3=9.5 Hz, 1H; GlcA^IIH-2), 5.04 (dd, J_4,5=9.5 Hz, 1H;

GlcA^IIH-4), 5.0–4.97 (m, 2H; GlcA^IH-1, GlcA^IIH-1), 4.94 (dd, J_1,2

=

6.0 Hz, J_2,3=4.0 Hz, 1H; GlcA^IH-2), 4.89 (dd, J_3,4=6.0 Hz, 1H; GlcA^I

H-3), 4.85 (ABq, 2H; CH₂Ar), 4.78–4.74 (m, 2H; GalN H-1, GlcA^IIH-

3), 4.60 (d, J_4,5=5.0 Hz, 1H; GlcA^IH-5), 4.42 (d, J_1,2=8.0 Hz, 1H; GalN

H-1), 4.30 (dd, 1H; GlcA^IH-4), 4.25–4.18 (m, 3H; 2GalN H-2, GlcA^II

H-5), 4.08–3.96 (m, 7H; GalN H-3, 2H-5, 4H-6), 3.92 (dd, J_2,3=11.0 Hz,

1H; GalN H-3), 3.72, 3.67 (2s, 6H; 2COOCH₃), 2.80–2.40 (m, 4H;

CH₂CO), 2.12 (s, 3H; COCH₃), 1.38, 1.24 ppm (2s, 6H; 2NHCOCH₃);

CS-K tetrasaccharide acetamide 65: From ester 63 (118 mg, 60 mmol) as

described for the preparation of 11. Flash silica chromatography

(CH₂Cl₂/MeOH 16:1) gave the intermediate tetrol (88 mg, 88%): M.p.

236–2388C (from EtOH); [a]²_D²=ꢀ6 (c=1 in chloroform); MS: m/z: 1686

9594

www.chemeurj.org

ꢁ 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Chem. Eur. J. 2009, 15, 9579 – 9595

Stereocontrolled Construction of Size-Defined Oligomers

FULL PAPER

HRMS: m/z: calcd for [C₇₄H₇₄N₂Na₄O₄₁S₄ꢀ4Na+4H]^2ꢀ: 888.1403; found:

H-2), 2.08, 2.06 ppm (2s, 6H; 2NHCOCH₃); ¹³C NMR (100 MHz, D₂O,

internal acetone, d_C=30.83): d=177.42, 175.35, 175.31 (GlcA C-6),

175.26, 175.02 (NHCO), 104.18, 103.83, 103.71 (GlcA C-1), 100.81

(GalN^IIC-1), 95.48 (GalN^IC-1b), 91.55 (GalN^IC-1a), 84.18 (GlcA^IIC-3),

81.28 (GlcA^IC-3), 81.11, 80.68 (GalN C-3), 80.66 (GlcA^IC-4), 77.64,

77.35 (GalN C-5), 76.36 (GlcA^IIC-5), 73.01 (GlcA^IC-5), 72.53 (GlcA^II

C-4), 70.83 (GlcA^IIC-2), 68.62, 68.52 (GlcA^IC-2), 68.18, 66.66 (GalN C-

4), 67.84, 76.36, 66.63 (GalN C-6), 52.36, 51.24, 49.10 (GalN C-2), 22.90,

888.1409.

CS-K tetrasaccharide glycoside 69: From ester 67 (59 mg, 31 mmol) as de-

scribed for the preparation of 19 to give the sodium salt 69 (38 mg, 88%)

as a white powder. R_f=0.30 (EtOAc/MeOH/water 5:3:2); [a]²_D²=ꢀ27

(c=1 in water); ¹H NMR (400 MHz, D₂O, internal HOD, d_H=4.79): d=

8.0–7.40 (m, 7H; arom. H), 4.96 (ABq, 2H; CH₂Ar), 4.76, 4.74 (2dd,

J

_3,4=2.5 Hz, J_4,5<1 Hz, 2H; 2GalN H-4), 4.61, 4.59 (2d, J_1,2=8.0 Hz, 2H;

2GalN H-1), 4.55, (d, J_1,2=7.5 Hz, 1H; GlcA^IIH-1), 4.53 (d, J_1,2=7.5 Hz,

1H; GlcA^IH-1), 4.36 (dd, J_2,3=J_3,4=9.5 Hz, 1H; GlcA^IH-3), 4.28 (dd,

22.58,

22.35 ppm

(NHCOCH₃);

HRMS:

m/z:

calcd

for

[C₂₈H₃₈N₂Na₆O₃₅S₄ꢀ4Na+4H]^2ꢀ: 569.0045; found: 569.0051.

J

_2,3=J_3,4=9.5 Hz, 1H; GlcA^IIH-3), 4.08–3.98 (m, 4H; 2GalN H-2, GalN

H-3, GlcA^IH-4), 3.96 (dd, J_2,3=11.0 Hz, 1H; GalN H-3), 3.84–3.78 (m,

4H; GalN H-5, H-6, 2GlcA H-5), 3.77–3.68 (m, 5H; GalN H-5, 3H-6,

GlcA^IH-4), 3.64 (dd, 1H; GlcA^IH-2), 3.50 (dd, 1H; GlcA^IIH-2), 1.98,

1.84 ppm (2s, 6H; 2NHCOCH₃); HRMS: m/z: calcd for

[C₃₉H₄₆N₂Na₆O₃₅S₄ꢀ4Na+4H]^2ꢀ: 639.0358; found: 639.0348.

Acknowledgements

CS-L tetrasaccharide glycoside 70: From ester 68 (56 mg, 30 mmol) as de-

scribed for the preparation of 19 to give the sodium salt 70 (37 mg, 90%)

as a white powder. R_f=0.35 (EtOAc/MeOH/water 5:3:2); [a]²_D²=ꢀ26

(c=1 in water); ¹H NMR (400 MHz, D₂O, internal HOD, d_H=4.79): d=

This work was supported by the Agence Nationale de la Recherche, Pro-

gramme ANR-05-BLAN-0198-02 “GT-GAG”.

8.0–7.40 (m, 7H; arom. H), 4.94 (ABq, 2H; CH₂Ar), 4.56 (d, J_1,2

7.5 Hz, 1H; GlcA^IH-1), 4.53 (d, J_1,2=7.5 Hz, 1H; GlcA^IIH-1), 4.52 (d,

_1,2=8.5 Hz, 2H; 2GalN H-1), 4.38–4.32 (m, 2H; GalN H-6, GlcA^IH-3),

=

[1] K. Sugahara, S. Yamada, Trends Glycosci. Glycotechnol. 2000, 12,

321–349.

J

[2] K. Sugahara, T. Mikami, T. Uyama, S. Mizoguchi, K. Nomura, H.

Kitagawa, Curr. Opin. Struct. Biol. 2003 , 13 , 61 2 –6 20.

[3] H. Kawashima, K. Atarashi, M. Hirose, J. Hirose, S. Yamada, K. Su-

gahara, M. Miyasaka, J. Biol. Chem. 2002 , 277 , 1292 1 –1 2930.

[4] C. D. Nandini, T. Mikami, M. Ohta, N. Itoh, F. Akiyama-Nambu, K.

Sugahara, J. Biol. Chem. 2004 , 279 , 5079 9 –5 0809.

4.27 (dd, J_2,3=J_3,4=9.5 Hz, 1H; GlcA^IIH-3), 4.25–4.17 (m, 3H; 3GalN

H-6), 4.16, 4.13 (2dd, J_3,4=3.0 Hz, J_4,5<1 Hz, 2H; 2GalN H-4), 4.04–3.97

(m, 2H; 2GalN H-2), 3.96 (dd, J_3,4=J_4,5=9.5 Hz, 1H; GlcA^IH-4), 3.90–

3.85 (m, 2H; 2GalN H-5), 3.82–3.76 (m, 2H; GalN H-3, GlcA^IH-5), 3.72

(d, J_4,5=9.5 Hz, 1H; GlcA^IIH-5), 3.69 (dd, J_2,3=11.0 Hz, 1H; GalN H-3),

3.64 (dd, J_4,5=9.5 Hz, 1H; GlcA^IIH-4), 3.53 (dd, 1H; GlcA^IH-2), 3.44

(dd, 1H; GlcA^IIH-2), 1.98, 1.80 ppm (2s, 6H; 2NHCOCH₃); HRMS:

[5] C. I. Gama, L. C. Hsieh-Wilson, Curr. Opin. Chem. Biol. 2005 , 9 ,

60 9 –6 19.

m/z: calcd for [C₃₉H₄₆N₂Na₆O₃₅S₄ꢀ4Na+4H]^2ꢀ

:

639.0358; found:

[6] a) J.-I. Tamura, Y. Nakada, K. Taniguchi, M. Yamani, Carbohydr.

Res. 2008 , 343 , 3 9 –4 7; b) S. E. Tully, R. Mabon, C. I. Gama, S. M.

Tsai, X. Liu, L. C. Hsieh-Wilson, J. Am. Chem. Soc. 2004 , 126 ,

773 6 –7 737; c) J. Tamura, M. Tokuyoshi, Biosci. Biotechnol. Bio-

chem. 2004 , 68 , 243 6 –2 443; d) N. Karst, J.-C. Jacquinet, Eur. J. Org.

Chem. 2002 , 81 5 –8 25; e) F. Bꢀlot, J.-C. Jacquinet, Carbohydr. Res.

2000, 326, 88–92; f) N. Karst, J.-C Jacquinet, J. Chem. Soc. Perkin

Trans. 1 2000 , 270 9 –2 717; g) J.-I. Tamura, K. Neumann, S. Kurono,

T. Ogawa, Carbohydr. Res. 1998, 306–314, 43–63.

[7] A. Lubineau, D. Bonnaffꢀ, Eur. J. Org. Chem. 1999 , 252 3 –2 532.

[8] S. Kobayashi, M. Ohmae, H. Ochiai, S.-I. Fujikawa, Chem. Eur. J.

2006 , 12 , 596 2 –5 971.

[9] C. Lopin, J.-C. Jacquinet, Angew. Chem. 2006 , 118 , 263 6 –2 640;

Angew. Chem. Int. Ed. 2006 , 45 , 257 4 –2 578.

[10] For Part 1, see: A. Vibert, C. Lopin-Bon, J.-C. Jacquinet, Chem. Eur.

J. 2009, 15, 9561–9578.

[11] J. Xia, S. A. Abbas, R. D. Locke, C. F. Piskorz, J. L. Alderfer, K. L.

Matta, Tetrahedron Lett. 2000 , 41 , 16 9 –1 73.

[12] G. Blatter, J.-M. Beau, J.-C. Jacquinet, Carbohydr. Res. 1994 , 260 ,

18 9 –2 02.

[13] R. R. Schmidt, Angew. Chem. 1986 , 98 , 21 3 –2 36; Angew. Chem. Int.

Ed. Engl. 1986 , 25 , 21 2 –2 35.

639.0353.

CS-K tetrasaccharide 71: From glycoside 69 (61 mg, 45 mmol) as de-

scribed for the preparation of 25 to give the target tetrasaccharide 71

(51 mg, 93%) as a white powder. R_f=0.20 (EtOAc/MeOH/water 4:3:2);

[a]²_D²=ꢀ8 (c=1, equil., in water); ¹H NMR (400 MHz, D₂O, internal

HOD, d_H=4.79): d=5.20 (d, J_1,2=3.5 Hz; GalN^IH-1a), 4.82, 4.78 (2dd,

J

_3,4=2.0 Hz, J_4,5<1 Hz, 2H; 2GalN H-4), 4.72 (d, J_1,2=8.0 Hz; GalN^IH-

1b), 4.64 (d, J_1,2=8.0 Hz, 1H; GalN^IIH-1), 4.61, 4.58 (2d, J_1,2=7.5 Hz,

1H; GlcA^IH-1a,H-1b), 4.56 (d, J_1,2=7.5 Hz, 1H; GlcA^IIH-1), 4.38 (dd,

J

_2,3=J_3,4=9.5 Hz, 1H; GlcA^IH-3), 4.32–4.26 (m; GalN^IH-2a, GlcA^IIH-

3), 4.15 (dd, J_2,3=11.0 Hz; GalN^IH-3a), 4.05 (dd, J_4,5=9.5 Hz, 1H; GlcA^I

H-4), 4.04–3.97 (m; GalN^IH-2b, GalN^IIH-2, H-3), 3.86–3.70 (m, 11H;

2GalN H-5, 4GalN H-6, GlcA^IIH-4, 2GlcA H-5), 3.65 (dd, 1H; GlcA^I

H-2), 3.48 (dd, 1H; GlcA^IIH-2), 2.03, 2.02, 2.01 ppm (3s, 6H;

2NHCOCH₃); ¹³C NMR (100 MHz, D₂O, internal acetone, d_C=30.83):

d=175.69, 175.57 (GlcA C-6), 175.36, 174.49 (NHCO), 103.82, 103.76

(GlcA C-1), 101.85 (GalN^IIC-1), 95.60 (GalN^IC-1b), 91.85 (GalN^IC-1a),

84.20 (GlcA^IIC-3), 82.08 (GlcA^IC-3), 78.70, 78.66 (GalN C-3), 78.01

(GlcA^IC-4), 76.95, 76.63 (GalN C-4), 76.42 (GalN C-5, GlcA^IIC-5),

75.05 (GalN C-6, GlcA^IC-5), 72.49 (GlcA^IIC-4), 71.86, 71.03 (GlcA C-

2), 61.74, 61.61 (GalN C-6), 53.25, 52.20, 49.90 (GalN C-2), 23.23, 22.92,

22.71 ppm

(NHCOCH₃);

HRMS:

m/z:

calcd

for

[14] S. David, S. Hanessian, Tetrahedron 1985 , 41 , 64 3 –6 63.

[15] F. Bꢀlot, J.-C. Jacquinet, Carbohydr. Res. 2000, 325, 93–106.

[16] J.-C. Jacquinet, Carbohydr. Res. 1990 , 199 , 15 3 –1 81.

[17] H. Lucas, J. E. M. Basten, T. G. van Dinther, D. G. Meuleman, S. F.

van Aelst, C. A. A. van Boeckel, Tetrahedron 1990 , 46 , 820 7 –8 228.

[18] K. Sugahara, S. Nadanaka, K. Takeda, T. Kojima, Eur. J. Biochem.

1996 , 239 , 87 1 –8 80.

[C₂₈H₃₈N₂Na₆O₃₅S₄ꢀ4Na+4H]^2ꢀ: 569.0045; found: 569.0059.

CS-L tetrasaccharide 72: From glycoside 70 (47 mg, 34 mmol) as de-

scribed for the preparation of 25 to give the target tetrasaccharide 72

(39 mg, 92%) as a white powder. R_f=0.25 (EtOAc/MeOH/water 4:3:2);

[a]²_D²=ꢀ10 (c=1, equil., in water); ¹H NMR (400 MHz, D₂O, internal

HOD, d_H=4.79): d=5.25 (d, J_1,2=3.5 Hz; GalN^IH-1a), 4.72 (d, J_1,2

=

8.0 Hz; GalN^IH-1b), 4.70, 4.66 (2d, J_1,2=7.5 Hz, 1H; GlcA^IH-1a,H-1b),

4.63 (d, J_1,2=7.5 Hz, 1H; GlcA^IIH-1), 4.61 (d, J_1,2=8.0 Hz, 1H; GalN^II

H-1), 4.43 (dd, J_2,3=J_3,4=9.5 Hz, 1H; GlcA^IH-3), 4.40–4.32 (m; GalN^I

H-2a, GalN H-6, GlcA^IIH-3), 4.30–4.16 (m; GalN^IH-3b, GalN H-3,

2GalN H-4, 3GalN H-6), 4.08–4.0 (m, GalN^IH-2b, GalN H-2, GlcA^IH-

4), 3.96 (m, 1H; GalN H-5), 3.90–3.83 (m; GalN H-3, H-5, GlcA^IH-5),

3.78 (d, J_4,5=9.5 Hz, 1H; GlcA^IIH-5), 3.68 (dd, J_3,4=9.5 Hz, 1H; GlcA^II

H-4), 3.64 (m, 1H; GlcA^IH-2a,H-2b), 3.50 (dd, J_2,3=9.5 Hz,1H; GlcA^II

[19] A. D. Lander, Curr. Opin. Neurobiol. 1993 , 3 , 71 6 –7 23.

[20] K. Sugahara, Y. Tanaka, S. Yamada, Glycoconjugate J. 1996 , 13 ,

60 9 –6 19.

[21] K. Sugahara, Y. Tanaka, S. Yamada, N. Seno, H. Kitagawa, S. M.

Haslam, H. R. Morris, A. Dell, J. Biol. Chem. 1996, 271, 26745–

26754.

Received: March 23, 2009

Published online: July 20, 2009

Chem. Eur. J. 2009, 15, 9579 – 9595

ꢁ 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

www.chemeurj.org

9595

Article Doi

From polymer to size-defined oligomers: A highly divergent and stereocontrolled construction of chondroitin sulfate A, C, D, E, K, L, and M oligomers from a single precursor: Part 2

DOI: 10.1002/chem.200900741

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