Convergent stereoselective synthesis of multiple sulfated GlcNα(1,4)GlcAβ(1,4) dodecasaccharides

Article abstract of DOI:10.1039/c2ob26928g

In this paper, we describe an effective method for the elongation of a GlcNα(1,4)GlcAβ(1,4) sequence using a GlcNTrocα(1,4)GlcA disaccharide unit and the synthesis of the N- and/or O-sulfated GlcNα(1,4)GlcAβ(1,4) oligosaccharides. N-Troc protection of Glc

Full text of DOI:10.1039/c2ob26928g

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PAPER
Convergent stereoselective synthesis of multiple
sulfated GlcNα(1,4)GlcAβ(1,4) dodecasaccharides†
Cite this: DOI: 10.1039/c2ob26928g
Hiroshi Tanaka,* Yusuke Tateno and Takashi Takahashi*
In this paper, we describe an effective method for the elongation of a GlcNα(1,4)GlcAβ(1,4) sequence
using a GlcNTrocα(1,4)GlcA disaccharide unit and the synthesis of the N- and/or O-sulfated GlcNα(1,4)-
GlcAβ(1,4) oligosaccharides. N-Troc protection of GlcNα(1,4)GlcA units was effective for the synthesis of
the GlcNα(1,4)GlcAβ(1,4) oligosaccharides in comparison with the azido substituent. The GlcNα(1,4)-
GlcAβ(1,4) dodecasaccharide was successfully prepared by the direct β-selective glycosidation of glucuro-
nate in the GlcNα(1,4)GlcAβ(1,4)GlcNα(1,4)GlcAβ(1,4) tetrasaccharide. In addition, the synthesis of the
N- and/or O-sulfated GlcNα(1,4)GlcAβ(1,4) oligosaccharides was accomplished by fluorous-assisted depro-
tection and sulfation. The fluorous-assisted synthetic technology applied to the highly polar sulfated
oligosaccharide permits it to be more easily separated from the highly polar reagents, such as SO3·NEt3.
Received 1st October 2012,
Accepted 17th October 2012
DOI: 10.1039/c2ob26928g
www.rsc.org/obc
oligosaccharides which are expected to have enhanced biologi-
cal activity compared to smaller oligosaccharides5 is still a
Introduction
Heparan sulfates (HS) and heparins (H) are partially sulfated difficult task, because (1) uronic acids are relatively unreactive
heterogeneous polysaccharides that are composed of α-glucos- towards both glycosylation and glycosidation due to the strong
amine (GlcN) and β-glucuronic acid (GlcA) or β-iduronic acid electron-withdrawing effect of the carboxyl group at the 6 posi-
(IdoA) units and are biologically synthesized by the partial tion,6 (2) difficulties associated with producing an α-glucosa-
enzymatic modification of heparosan, a homopolymer com- mine linkage7 and (3) the high polarity of multiply sulfated
posed of a GlcNα(1,4)GlcAβ(1,4) sequence. These sulfated oligosaccharides.
A post-glycosylation oxidation approach
oligosaccharides play crucial roles in a variety of biological where the oligosaccharide backbone is built up prior to the
systems such as bacterial infections, growth factor regulation, installment of the carboxylate functions is an effective way to
angiogenesis, cell adhesion and lipid metabolism1 and avoid these difficulties. However, this approach requires the
promote the growth of human embryonic stem cells in a oxidation of multiple C6 hydroxyl groups of complex oligo-
defined serum-free medium.2 However, elucidating the struc- saccharides at the last stage in the synthesis of sulfated oligo-
ture–activity relationships of such oligosaccharides is a daunt- saccharides. On the other hand, an IdoAβ(1,4)GlcN3
ing task, since a great deal of heterogeneity can exist, because disaccharide represents an effective building block for the syn-
of the sugars contained by the oligosaccharide and the fact thesis of the oligosaccharides based on a pre-glycosylation oxi-
that the number and position of sulfate esters and IdoA units dation approach.8 Lortat-Jacob et al. successfully synthesized a
can vary greatly. Methodology for the chemical synthesis of heparin GlcNα(1,4)IdoAβ(1,4) dodecasaccharide containing 18
structurally defined pure HS/H related oligosaccharides would sulfate esters using a building block approach.9 However, it is
greatly contribute not only to the elucidation of their struc- still difficult to prepare oligosaccharides containing alternat-
ture–activity relationships, but could also lead to the develop- ing GlcN and GlcA units that serve as substrates for enzymatic
ment of new drug candidates based on the structure of HS/H.
modification as well as ligands of the heparin receptors.10 The
Recent developments in synthetic carbohydrate chemistry corresponding GlcAβ(1,4)GlcN3 unit did not function well,
now permit various sulfated oligosaccharides to be prepared.3,4 since glycosylation of the C4 equatorial hydroxyl group of the
However, the synthesis of relatively large sulfated 4C1 conformer of the D-glucuronyl acceptor with the GlcN3
donor frequently resulted in the formation of anomeric mix-
tures.11 Therefore, an effective method for the synthesis of
Department of Applied Chemistry, Graduate School of Science and Engineering,
these heparosan oligosaccharides continues to be needed.
Herein we proposed the GlcNTrocα(1,4)GlcA disaccharide unit
Tokyo Institute of Technology, 2-12-1-H-101 Ookayama, Meguro, Tokyo 152-8552,
Japan. E-mail: thiroshi@apc.titech.ac.jp; Fax: +81-3-5734-2884;
as a new building block for the synthesis of sulfated dodeca-
Tel: +81-3-5734-2471
†Electronic supplementary information (ESI) available. See DOI: 10.1039/
saccharides composed of alternating GlcNα(1,4)GlcAβ(1,4)
sequences.12
c2ob26928g
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tag to the protected oligosaccharides facilitates their purifi-
cation and improves efficiency of the deprotection process
Results and discussion
We planned the synthesis of the N- and O-sulfated GlcNα(1,4)- with minimal effects on their reactivity.14 We previously
GlcAβ(1,4) dodecasaccharides 1 and 2 containing a thioester at reported on a methodology for the solid- and fluorous-assisted
the reducing end (Scheme 1). The N-sulfated oligosaccharides deprotection of oligosaccharides that ease the manipulation of
1 and 2 are expected to act as substrates for enzymatic modifi- highly polar substrates.15 The 2-naphthylmethyl (NAP) ethers
cation as well as ligands of the heparin receptors. The thio- and the N-trichloroethylcarbonyl (Troc) protecting groups are
benzoate moiety acts as a chromophore for detecting the final selectively removed for the partial sulfation of the oligo-
product as well as a linking device for further derivatization saccharides. The tetrasaccharide 5 was prepared by the chemo-
via S-alkylation. Strategy for the synthesis of the sulfated oligo- selective and β-selective glycosylation of the disaccharide
saccharides 1 and 2 is based on a [4 + 4 + 4] coupling strategy donor 7 and acceptor 8. The disaccharide is prepared by the
using the tetrasaccharide 5 and a fluorous-assisted deprotec- chemoselective and α-selective glycosylation of 9 with 10.
tion using the fluorous tag 3. The dodecasaccharides 1 and 2
Scheme 2 shows preparation of the GlcNα(1,4)GlcAβ(1,4)
would be prepared from two tetrasaccharide donors 5 and disaccharides 7 and 8 from 11. The α-thioglycoside 11 was con-
tetrasaccharide acceptor 6. The C2 benzoate of the glucuronate verted to acetal 12 by hydrolysis of the acetates, acetalization
unit in 5 promotes β-selectivity in the glycosidation of tetra- of C4,6 dihydroxyl groups with 2-naphthylaldehyde and etheri-
saccharide 5. The N-Troc protecting group improves the reac- fication of the C3 hydroxyl group with benzyl bromide. Regio-
tivity of the C4 hydroxyl group towards glycosylation.12 The selective cleavage of the acetal with BH3·NMe3 and AlCl3,
chloroacetyl group can be selectively removed without affecting followed by protection of the resulting C4 hydroxyl group with
any other protecting groups for conversion to a glycosyl accep- chloroacetyl chloride provided the naphthylmethylether 13 in
tor. The use of large building blocks improves the efficiency of 78% yield. Oxidative hydrolysis of the thioglycoside with NBS
the synthesis of oligosaccharides and facilitates the separation provided hemiacetal 10 in 76% yield. Treatment of the hemi-
of the product from the substrates by size exclusion chromato- acetal 10 and thioglycoside 9 with Tf2O, Ph2SO and TTBP pro-
graphy.13 The sulfation, deprotection and installation of the vided the α-linked disaccharide 14 in 72% yield with excellent
chromophore with the activated ester 3 would be achieved α-selectivity (α/β = 92/8). Removal of the chloroacetyl group
after attaching a light-fluorous tag. Attaching a light-fluorous with thiourea, followed by reduction of azide to amine with
Scheme 1 Strategy for the synthesis of the sulfated GlcNα(1,4)GlcAβ(1,4) dodecasaccharides 1 and 2.
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Scheme 3 Synthesis of the octasaccharide 25 from N-Troc protected
disaccharide.
the N-Troc disaccharide 18 with 1.5 equivalents of the N-Troc
thioglycoside 16 provided the tetrasaccharide 20 in 63% yield
with complete β selectivity, along with the recovery of the
acceptor 18 (30%). On the other hand, when attempts were
made to couple the azide derivatives 14 and 19, the tetrasac-
charide 21 was produced in a reduced yield (25%) with a sig-
Scheme 2 Preparation of the disaccharide building blocks 9 and 10.
1,3-propane dithiol provided the amino alcohol 15 in 87% nificant amount of the acceptor 19 being recovered (59%). The
overall yield. Treatment of the amino alcohol 15 with N-TrocCl electron withdrawing azide substituent that directs the α-selec-
without base chemoselectively provided the N-Troc protected tive glycosylation of the glucosamine unit would reduce the
thioglycoside 8 in 90% yield. The remaining alcohol 8 was acy- reactivity of the C4 hydroxyl group towards glycosylation to a
lated with chloroacetyl unhydride to afford the thioglycoside considerable extent in comparison with the (2,2,2-trichloro-
16 in 94% yield. Hydrolysis of the thioglycoside 16 with NBS ethyloxy)carbonylamino substituent. The synthesis of the hexa-
(74%), followed by treatment of the hemiacetal 17 with tri- and octa-saccharides 22 and 24 from the N-Troc protected tet-
chloroacetonitrile under basic conditions provided the glycosyl rasaccharide 20 was examined. Selective hydrolysis of the
imidate 7. The glycosyl imidate 7 was used for the glycosida- chloroacetyl ester of 20 was achieved by treatment with
tion after brief purification.
thiourea to provide the tetrasaccharide acceptor 6 in 96%
We next examined the effect of the 2-azide and 2-(2,2,2-tri- yield. Glycosylation of the tetrasaccharide 6 with the disacchar-
chloroethyloxy)carbonylamino groups of a glucosamine unit ide donor 16 proceeded smoothly under the same glycosyla-
on the coupling of disaccharides (Scheme 3). Both of the sub- tion conditions to provide the hexasaccharide 22 in 68% yield.
stituents are known to improve the reactivity of the The desired hexasaccharide 22 was separated from the tetra-
C4 hydroxyl group towards glycosylation.12,13 Glycosylation of saccharide acceptor 6 by preparative HPLC using a gel
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Scheme 4 Synthesis of the protected dodecasaccharide 28 by glycosidation of the tetrasaccharide donor 5.
permeable chromatography column. Hydrolysis of the chloro- fluorous tag 3 with an attached DHP moiety and the dodeca-
acetyl ester of 22 by treatment with thiourea provided the hexa- saccharide 27 via acetalization provided the fluorous tag-
saccharide acceptor 23 in 93% yield. Glycosylation of the attached dodecasaccharide 28 in 91% yield. Removal of the
hexasaccharide acceptor 23 with the disaccharide donor 16 NAP esters of 28 by treatment with DDQ under mildly basic
provided the octasaccharide 24 in 58% yield. These results conditions to provide hexaol, followed by O-sulfation of the
indicate that the N-Troc protected glucosamines 18, 6 and 23 resulting hydroxyl groups with a large excess of SO3·NEt3 in
should be effective glycosyl acceptors for the synthesis of HS/H the presence of NEt3 at 50 °C for 24 h provided the 6-O-sulfated
derivatives. Although the conversion of the amino substituent oligosaccharide 29 in 55% yield in 2 steps. Removal of the
needs additionally two steps, the improved coupling efficiency Troc groups was achieved by treatment with Zn in acetic acid
would be effective for the synthesis of large oligosaccharides. to provide the hexaamine, followed by N-sulfation with a large
However, the purification of the octasaccharide 24 from the excess amount of SO3·NEt3, which provided the N- and O-sul-
remaining hexasaccharide acceptor 23 was laborious, due to fated dodecasaccharide 30 in 22% yield. De-monochlorination
the small difference in both their molecular weights and their of the 2,2,2-trichloroethyl carbamate to the 2,2-dichloroethyl
Rf values on the TLC plate.
carbamate reduced the yield of 30. Work-up and purification
Synthesis of the protected dodecasaccharide 27 from the for the O- and N-sulfated compounds that were prepared using
tetrasaccharide donor 5 was also examined (Scheme 4). The a large excess of sulfating reagents was simply achieved by a
tetrasaccharide 5 was prepared by chemoselective glycosylation fluorous solid-phase extraction (F-SPE). Removal of the remain-
of thioglycoside 8 with glycoyl imidate 7. Treatment of the ing protecting group of 30 under Birch reduction conditions
tetrasaccharide acceptor 6 with 1.5 equivalents of the tetra- after hydrolysis of the methyl esters, acylation of the resulting
saccharide donor 5 in the presence of NIS and a catalytic primary amine with the activated ester 4, followed by cleavage
amount of TfOH at −20 °C for 2 h provided octasaccharide of the fluorous tag under acidic conditions provided the
24 in 69% yield. Treatment of the octasaccharide 24 with N- and 6-O-sulfated dodecasaccharide 1 in 60% yield. Omitting
thiourea under basic conditions provided the octasaccharide the 6-O-sulfation provided the N-sulfated dodecasaccharide 2
glycosyl acceptor 25 in 96% yield. Treatment of the octasacchar- in 11% overall yield based on 28.
ide acceptor 25 and 1.5 equivalents of the tetrasaccharide donor
5 with NIS and a catalytic amount of TfOH at −20 °C for 2 h pro-
vided the dodecasaccharide 26 in 68% yield. Removal of the
chloroacetyl group of 26 afforded the tetrasaccharide acceptor
Conclusions
27 in 96% yield in which the hydroxyl group would be used as a
functional group for attaching with the fluorous tag.
Fluorous-assisted modification of the protected oligosac-
charides to multiple sulfated GlcNα(1,4)GlcAβ(1,4) oligosac-
charides 1 and 2 was examined (Scheme 5). Coupling of the
In conclusion, an efficient synthesis of the N- and 6-O-sulfated
heparosan dodecasaccharide 18 composed of a GlcNα(1,4)-
GlcAβ(1,4) sequence based on the coupling of GlcNTrocα(1,4)-
GlcA disaccharides is described. N-Troc protection of glyco-
samine was effective for improving reactivity towards
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Scheme 5 Fluorous-assisted synthesis of the sulfated oligosaccharides 1 and 2 from the protected disaccharide 31.
glycosylation at the C4 hydroxyl group in comparison with that
of the 2-azide derivative of glucosamine. These building blocks
Experimental
Phenylthio 2-azido-3-O-benzyl-2-deoxy-4,6-O-naphthylidene-
α-D-glucopyranoside (12)
would be effective for the synthesis of not only the sulfated
heparosan oligosaccharides, but also the HS/S related oligosac-
charide containing both GlcA and IdoA. In addition, this To a solution of 11 (1.22 g, 2.90 mmol) in MeOH (10 mL) was
method provided various heparosan oligosaccharide deriva- added 1 M NaOMe in MeOH (3 mL). The reaction mixture was
tives as effective substrates for enzymatic modification to left to stand at room temperature for 5 h, and neutralized with
produce various HS/S derivatives.
acetic acid. After removal of the solvent in vacuo, the residue
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was used for the next reaction without further purification. To J = 5.3 Hz), 5.21 (dd, 1H, J = 9.2, 10.1 Hz), 4.90 (d, 1H, J = 11.1
a stirred solution of the residue in dry DMF (5.80 mL) was Hz), 4.66 (d, 1H, J = 11.6 Hz), 4.63 (d, 1H, J = 11.1 Hz), 4.56 (d,
added 2-naphthaldehyde (6.79 g, 4.35 mmol), HC(OMe)3 1H, J = 11.6 Hz), 4.49 (ddd, 1H, J = 1.9, 4.3, 10.1 Hz), 4.01 (dd,
(6.09 mL, 5.80 mmol) and CSA (2.02 g, 8.70 mmol) at room 1H, J = 5.3, 9.7 Hz), 3.80 (dd, 1H, J2,3 = 9.2, 9.7 Hz), 3.61 (d, 1H,
temperature. After being stirred at 70 °C for 36 h, the reaction J = 15.0 Hz), 3.52–3.56 (m, 2H), 3.51 (d, 1H, J = 15.0 Hz); 13C
mixture was neutralized with NEt3 and poured into ice-cooled NMR (100 MHz, CDCl3) δ 166.1, 137.5, 135.0, 133.2, 133.1,
1 M HCl. The aqueous layer was extracted with two portions of 132.9, 132.3, 129.2, 128.7, 128.2 × 2, 128.0 × 2, 127.8, 126.8,
ethyl acetate. The combined extract was washed with a satu- 126.2, 126.0 × 2 (87.0 anomeric), 79.3, 77.3, 75.4, 73.8, 72.5,
rated aq. NaHCO3 solution and brine, dried over MgSO4, fil- 69.8, 68.7, 64.0, 40.5; IR (KBr) 3459, 3060, 2109, 1770, 1743,
tered and evaporated in vacuo. The residue was used for the 1365, 1253, 1167, 741, 699 (cm−1); HRMS (ESI-TOF) calcd for
next reaction without further purification. To a stirred solution C32H34N4O5SCl [M + NH4]+ 621.1941, found 621.1938.
of the residue in dry THF (29.0 mL) was added NaH (139 mg,
2-Azido-3-O-benzyl-4-O-chloroacetyl-2-deoxy-6-O-
naphthylmethyl-D-glucopyranose (10)
3.19 mmol) and benzyl bromide (508 mg, 3.04 mmol) at 0 °C.
After being stirred at room temperature for 3 h, the reaction
mixture was neutralized with MeOH and poured into ice- To a stirred solution of 13 (560 mg, 0.929 mmol) in acetone
cooled 1 M HCl. The aqueous layer was extracted with two por- (4.65 mL) and H2O (0.465 mL) was added NBS (500 mg,
tions of ethyl acetate. The combined extract was washed with 2.71 mmol) at 0 °C. After being stirred at the same temperature
saturated aq. NaHCO3 and brine, dried over MgSO4, filtered for 6 h, the reaction mixture was poured into a mixture of satu-
and evaporated in vacuo. The residue was purified by column rated aq. NaHCO3 and 10% aq. Na2S2O3 with cooling. The
chromatography on silica gel (elution with hexane : ethyl aqueous layer was extracted with two portions of ethyl acetate.
acetate = 70 : 30) to give 12 (1.13 g, 2.15 mmol, 3 steps 74%): The combined extract was washed with saturated aq. NaHCO3
[α]3D0 +108 (c 1.07, CHCl3); 1H NMR (400 MHz, CDCl3) δ and 10% aq. Na2S2O3 and brine, dried over MgSO4, filtered
7.19–7.98 (m, 17H, aromatic), 5.71 (s, 1H), 5.55 (d, 1H, J = 5.3 and evaporated in vacuo. The residue was purified by column
Hz), 4.98 (d, 1H, J = 11.1 Hz), 4.83 (d, 1H, J = 11.1 Hz), 4.46 chromatography on silica gel (elution with hexane : ethyl
(ddd, 1H, J = 9.7 Hz, J = 4.8, 5.3 Hz), 4.25 (dd, 1H, J = 5.3, 10.1 acetate = 80 : 20) to give 10 (361 mg, 0.706 mmol, 76%) as an
Hz), 3.75–4.01 (m, 4H); 13C NMR (100 MHz, CDCl3) δ 137.7, anomeric mixture: 1H NMR (400 MHz, CDCl3) α anomer
134.5, 133.7, 133.0, 132.9, 132.5, 129.2, 128.5, 128.4, 128.2, (major); δ 7.25–7.83 (m, 12H, aromatic), 5.33 (d, 1H, J = 3.3
128.0, 127.8, 126.6, 126.3, 125.6, 123.7 (101.7 anomeric), 87.9, Hz), 5.07 (dd, 1H, J = 9.2, 9.6 Hz), 4.50–4.86 (m, 4H), 4.14 (m,
82.8, 77.9, 77.3, 75.2, 68.7, 63.9, 63.6; IR (KBr) 2903, 2109, 1H), 3.98 (dd, 1H, J = 9.2, 9.7 Hz), 3.75 (dd, 1H, J = 3.3, 9.7 Hz),
1478, 1363, 1093, 1022, 741, 698 (cm−1); HRMS (ESI-TOF) calcd 3.38–3.59 (m, 4H); 13C NMR (100 MHz, CDCl3) δ 166.3, 166.2,
for C30H28N3O4S [M + H]+ 526.1805, found 526.1801.
137.7, 134.8, 134.7, 133.3, 133.2 × 2, 128.6 × 2, 128.4, 128.1 × 3,
128.0, 127.8, 127.1 × 2, 126.3 × 2, 126.2 × 2, 126.1, 126.0 (96.3,
91.9 anomeric), 80.2, 75.1, 73.9, 72.9, 72.7, 72.2, 69.1, 69.0,
68.7, 67.1, 63.7, 40.4 × 2; IR (KBr) 3428, 2879, 2109, 1760,
Phenylthio 2-azido-3-O-benzyl-4-O-chloroacetyl-2-deoxy-6-O-
naphthylmethyl-α-D-glucopyranoside (13)
To a stirred solution of 12 (3.13 g, 5.95 mmol) and pulverized 1319, 1142, 1059, 754, 700 (cm−1); HRMS (ESI-TOF) calcd for
activated MS-4A (5.95 g) in dry THF (29.8 mL) was added C26H30N4O6Cl [M + NH4]+ 529.1855, found 529.1854.
BH3·NMe3 (2.60 g, 35.7 mmol) and AlCl3 (4.76 g, 35.7 mmol) at
room temperature. After being stirred at room temperature for
24 h, the reaction mixture was poured into an ice-cooled solu-
tion of 1 M H2SO4 and ethyl acetate for 20 min at 0 °C. The
Phenylthio 2-azido-3-O-benzyl-4-O-chloroacetyl-2-deoxy-6-O-
naphthylmethyl-α-D-glucopyranosyl-(1 → 4)-(methyl 2-O-
benzoyl-3-O-benzyl-β-D-glucopyranosyluronate (14)
aqueous layer was extracted with two portions of ethyl acetate. A mixture of 10 (300 mg, 0.586 mmol), Ph2SO (331 mg,
The combined extract was washed with saturated aq. NaHCO3 1.64 mmol), TTBP (436 mg, 1.76 mmol) and pulverized acti-
and brine, dried over MgSO4, filtered and evaporated in vacuo. vated MS-4A (586 mg) in dry CH2Cl2 (9.00 mL) was stirred at
The residue was used for the next reaction without further room temperature for 30 min under argon to remove trace
purification. To a stirred solution of the residue in dry CH2Cl2 amounts of water. Then the reaction mixture was cooled to
(59.5 mL) was added dry pyridine (0.959 mL, 59.5 mmol) and −60 °C. Tf2O (114 μL, 0.820 mmol, 1.40 equiv.) was added to
chloroacetyl chloride (1.14 mL, 14.3 mmol) at 0 °C. After being the reaction mixture at the same temperature. After being
stirred at room temperature for 1 h, the reaction mixture was stirred at −40 °C for 30 min, a solution of 9 (273 mg,
poured into ice-cooled 1 M HCl. The aqueous layer was 0.391 mmol) in dry CH2Cl2 (3.00 mL) was added at −60 °C and
extracted with two portions of ethyl acetate. The combined the reaction mixture was allowed to warm slowly to room temp-
extract was washed with 1 M HCl, saturated aq. NaHCO3 and erature. After being stirred at the same temperature for 5 h,
brine, dried over MgSO4, filtered and evaporated in vacuo. The the reaction mixture was neutralized with NEt3 and filtered
residue was purified by column chromatography on silica gel through a pad of Celite®. The filtrate mixture was poured into
(elution with hexane : ethyl acetate = 90 : 10) to 13 (2.80 g, brine. The aqueous layer was extracted with two portions of
1
4.64 mmol, 2 steps 78%): [α]2D9 +119 (c 1.13, CHCl3); H NMR ethyl acetate. The combined extract was washed with saturated
(400 MHz, CDCl3) δ 7.24–7.83 (m, 17H, aromatic), 5.61 (d, 1H, aq. NaHCO3 and brine, dried over Na2SO4, filtered and
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evaporated in vacuo. The residue was purified by column (dd, 1H, J = 8.7, 10.1 Hz), 2.70 (dd, 1H, J = 3.4, 10.1 Hz); 13C
chromatography on silica gel (elution with CHCl3 : MeOH = NMR (100 MHz, CDCl3) δ 168.1, 165.0, 138.9, 137.2, 135.1,
98 : 2) and by gel permeation chromatography (GPC) to give 14 133.5, 133.3, 133.1, 132.8, 132.4, 129.9, 129.7, 129.0, 128.6,
(417 mg, 0.422 mmol, 72%, β/α = 92/8). The β,α-isomers were 128.4 × 2, 128.2, 128.1, 128.0, 127.9, 127.8, 126.8, 126.3, 126.1
separated by column chromatography on silica gel to give the (100.2, 86.9 anomeric), 83.4, 83.0, 78.8, 77.3, 75.2, 75.1, 74.5,
α-isomer (elution with toluene : ethyl acetate = 99 : 1) and the 74.0, 73.5, 72.1, 70.6, 55.1, 52.8; IR (KBr) 3502, 2868, 1747,
β-isomer (elution with toluene : ethyl acetate = 98 : 2): [α]2D0 1718, 1452, 1268, 1218, 772 (cm−1); HRMS (ESI-TOF) calcd for
1
+45.1 (c 1.23, CHCl3); H NMR (400 MHz, CDCl3) δ 7.12–8.08 C51H52NO11S [M + H]+ 886.3274, found 886.3261.
(m, 27H, aromatic), 5.54 (d, 1H, J = 3.8 Hz), 5.34 (dd, 1H, J =
Phenylthio 3-O-benzyl-2-deoxy-6-O-naphthylmethyl-2-(2,2,2-
9.2, 9.7 Hz), 5.22 (dd, 1H, J = 9.7, 9.7 Hz), 4.88 (d, 1H, J =
trichloroethoxycarbonylamino)-α-D-glucopyranosyl-(1 → 4)-
9.7 Hz), 4.82 (d, 1H, J = 11.1 Hz), 4.76 (d, 1H, J = 10.6 Hz), 4.68
(methyl 2-O-benzoyl-3-O-benzyl-β-D-glucopyranosyluronate) (8)
(d, 1H, J = 10.6 Hz), 4.67 (d, 1H, J = 12.1 Hz), 4.59 (d, 1H, J =
11.1 Hz), 4.55 (d, 1H, J = 12.1 Hz), 4.25 (dd, 1H, J = 8.7, 9.7 Hz), To a stirred solution of 15 (3.88 g, 4.38 mmol) in THF
4.11 (d, 1H, J = 9.7 Hz), 4.03 (dd, 1H, J = 8.7, 9.2 Hz), 3.87 (dd, (60.0 mL) and H2O (20.0 mL) was added NaHCO3 (3.60 g,
1H, J = 9.7, 10.1 Hz), 3.72 (s, 3H), 3.60 (ddd, 1H, J = 3.4, 4.8, 43.8 mmol) and TrocCl (708 μL, 5.26 mmol) at 0 °C. After
9.7 Hz), 3.56 (m, 1H), 3.55 (d, 1H, J = 14.5 Hz), 3.48 (d, 1H, J = being stirred at the same temperature for 10 min, the reaction
14.5 Hz), 3.46 (dd, 1H, J = 3.4, 9.7 Hz), 3.36 (dd, 1H, J = 3.8, mixture was poured into brine. The aqueous layer was
10.1 Hz); 13C NMR (100 MHz, CDCl3) δ 168.3, 165.9, 165.0, extracted with two portions of ethyl acetate. The combined
137.6, 137.1, 135.0, 133.6, 133.3, 133.1, 132.9, 132.2, 129.9, extract was washed with brine, dried over Na2SO4, filtered and
129.6, 129.1, 129.0, 128.7, 128.6, 128.5, 128.3 × 3, 128.1 × 2, evaporated in vacuo. The residue was precipitated from ethyl
128.0, 127.9 × 2, 127.7, 127.0, 126.2, 126.1 × 2 (97.5, 87.0 acetate–hexane to 8 (4.20 g, 3.96 mmol, 90%): [α]2D0 +41.9 (c
anomeric), 83.9, 78.1, 77.4, 77.3, 74.9, 74.8, 74.7, 74.0, 72.7, 1.05, CHCl3); 1H NMR (400 MHz, CD2Cl2) δ 7.07–8.06 (m, 27H,
72.2, 69.0, 68.6, 62.9, 52.8, 40.5; IR (KBr) 3028, 2108, 1735, aromatic), 5.41 (d, 1H, J = 10.2 Hz), 5.30–5.35 (m, 2H), 4.90 (d,
1453, 1263, 1068, 772, 710 (cm−1); HRMS (ESI-TOF) calcd for 1H, J = 9.7 Hz), 4.78 (d, 1H, J = 12.5 Hz), 4.77 (d, 1H, J =
C53H54N4O12ClS [M + NH4]+ 1005.3147, found 1005.3159.
11.1 Hz), 4.71–4.74 (m, 2H), 4.68 (d, 1H, J = 11.6 Hz), 4.62 (s,
2H), 4.56 (d, 1H, J = 12.1 Hz), 4.21 (dd, 1H, J = 9.2, 9.2 Hz),
4.06 (d, 1H, J = 9.2 Hz), 3.98 (dd, 1H, J = 8.7, 9.2 Hz), 3.93 (ddd,
1H, J = 3.9, 10.2, 10.2 Hz), 3.80–3.86 (m, 2H), 3.76 (s, 3H), 3.69
(dd, 1H, J = 4.8, 10.1 Hz), 3.56–3.60 (m, 1H), 3.48 (dd, 1H, J =
Phenylthio 2-amino-3-O-benzyl-2-deoxy-6-O-naphthylmethyl-
α-D-glucopyranosyl-(1 → 4)-(methyl 2-O-benzoyl-3-O-benzyl-β-D-
glucopyranosyluronate) (15)
To a stirred solution of 14 (6.37 g, 6.44 mmol, 1.00 equiv.) in 9.2, 10.2 Hz); 13C NMR (100 MHz, CD2Cl2) δ 168.3, 165.2,
DMF (65.0 mL) was added thiourea (4.91 g, 64.4 mmol) and 154.5, 138.9, 137.1, 135.8, 133.9, 133.6, 133.4, 132.8, 132.7,
2,6-lutidine (1.15 mL, 7.73 mmol) at room temperature. After 130.1, 129.8, 129.4, 128.9, 128.8, 128.7, 128.5, 128.3, 128.2,
being stirred at 50 °C for 12 h, the reaction mixture was 128.1, 128.0 × 2, 126.9, 126.6, 126.4, 126.1 (98.8, 95.9 anome-
poured into ice-cooled 1 M HCl. The aqueous layer was ric), 87.5, 83.5, 79.8, 78.6, 77.9, 75.2, 75.0, 74.9, 74.7, 74.2,
extracted with two portions of ethyl acetate. The combined 72.8, 72.4, 71.2, 70.5, 54.8, 53.2; IR (KBr) 3370, 2953, 1736,
extract was washed with 1 M HCl, saturated aq. NaHCO3, and 1511, 1264, 1069, 768, 711 (cm−1); HRMS (ESI-TOF) calcd for
brine, dried over Na2SO4, filtered and evaporated in vacuo. The C54H53NO13SCl3 [M + H]+ 1060.2296, found 1060.2303.
residue was used for the next reaction without further
Phenylthio 3-O-benzyl-4-O-chloroacetyl-2-deoxy-6-O-
naphthylmethyl-2-(2,2,2-trichloroethoxycarbonylamino)-α-D-
glucopyranosyl-(1 → 4)-(methyl 2-O-benzoyl-3-O-benzyl-β-D-
glucopyranosyluronate) (16)
purification.
To a stirred solution of the residue in MeOH (64.0 mL) and
THF (5.0 mL) was added 1,3-propanedithiol (3.2 mL) and NEt3
(1.6 mL) at room temperature. After being stirred at the same
temperature for 24 h, to the reaction mixture was added 1,3- To a stirred solution of 16 (5.42 g, 5.11 mmol) in dry CH2Cl2
propanedithiol (3.2 mL) and NEt3 (1.6 mL) at the same temp- (51.0 mL) was added dry pyridine (2.07 mL, 25.6 mmol) and
erature. After being stirred at the same temperature for chloroacetic anhydride (1.05 g, 6.13 mmol) at 0 °C. After being
another 24 h, the reaction mixture was evaporated in vacuo. stirred at the same temperature for 2 h, the reaction mixture
The residue was purified by column chromatography on silica was poured into ice-cooled 1 M HCl. The aqueous layer was
gel (elution with toluene : ethyl acetate : NEt3 = 75.5 : 20 : 0.5) to extracted with two portions of ethyl acetate. The combined
give 15 (4.96 g, 5.60 mmol, 87%): [α]2D0 +57.8 (c 1.16, CHCl3); extract was washed with 1 M HCl, saturated aq. NaHCO3 and
1H NMR (400 MHz, CDCl3) δ 7.12–8.06 (m, 27H, aromatic), brine, dried over Na2SO4, filtered and evaporated in vacuo. The
5.32 (dd, 1H, J = 8.7, 9.7 Hz), 5.27 (d, 1H, J = 3.4 Hz), 4.92 (d, residue was precipitated from ethyl acetate–hexane to 16
1
1H, J = 11.6 Hz), 4.86 (d, 1H, J = 9.7 Hz), 4.71–4.78 (m, 3H), (5.45 g, 4.79 mmol, 94%): [α]2D0 +41.4 (c 1.41, CHCl3); H NMR
4.69 (d, 1H, J = 12.1 Hz), 4.59 (d, 1H, J = 10.6 Hz), 4.24 (dd, 1H, (400 MHz, CDCl3, 50 °C) δ 7.07–8.01 (m, 27H, aromatic), 5.35
J = 9.2, 9.2 Hz), 4.05 (d, 1H, J = 9.2 Hz), 3.91 (dd, 1H, J = 8.7, (s, 1H), 5.28–5.33 (m, 2H), 5.24 (dd, 1H, J = 9.7, 9.7 Hz), 4.85
9.2 Hz), 3.79 (dd, 1H, J = 3.4, 9.7 Hz), 3.71 (s, 3H), 3.68–3.71 (d, 1H, J = 9.7 Hz), 4.66 (d, 1H, J = 12.1 Hz), 4.55–4.63 (m, 6H),
(m, 1H), 3.62 (dd, 1H, J = 5.8, 9.7 Hz), 3.53–3.58 (m, 1H), 3.32 4.51 (d, 1H, J = 11.6 Hz), 4.23 (dd, 1H, J = 9.2, 9.2 Hz),
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3.94–4.05 (m, 3H), 3.73 (s, 3H), 3.66–3.70 (m, 4H), 3.63 (dd, under argon to remove trace amounts of water. Then the reac-
1H, J = 3.9, 14.5 Hz), 3.56 (dd, 1H, J = 4.8, 14.5 Hz); 13C NMR tion mixture was cooled to −40 °C. NIS (11.7 mg, 52.0 μmol)
(100 MHz, CDCl3) δ 167.9, 165.8, 164.9, 154.0, 137.8, 136.4, and TfOH (0.93 μL, 10.4 μmol) were added to the reaction
135.1, 133.6, 133.3, 133.1, 133.0, 132.1, 129.9, 129.5, 129.1, mixture at the same temperature. After being stirred at −20 °C
128.6 × 2, 128.5, 128.4, 128.3, 128.2, 128.1, 128.0, 127.9, 127.8 for 3 h, the reaction mixture was neutralized with NEt3 and fil-
× 2, 127.0, 126.2, 126.1 × 2 (98.4, 95.4 anomeric), 87.2, 82.8, tered through a pad of Celite®. The filtrate mixture was
78.5, 77.4, 77.3, 75.5, 74.7, 74.4, 74.0, 73.4, 72.6, 72.2, 69.6, poured into a mixture of saturated aq. NaHCO3 and saturated
69.0, 54.5, 52.9, 40.6; IR (KBr) 3029, 2925, 1736, 1510, 1262, aq. Na2S2O3 with cooling. The aqueous layer was extracted
1069, 752, 710 (cm−1); HRMS (ESI-TOF) calcd for with two portions of ethyl acetate. The combined extract was
C56H54NO14SCl4 [M + H]+ 1136.2003, found 1136.2019.
washed with saturated aq. NaHCO3 and saturated aq. Na2S2O3
and brine, dried over Na2SO4, filtered and evaporated in vacuo.
The residue was purified by column chromatography on silica
gel (elution with CHCl3 : MeOH = 98 : 2) to give 20 (48.6 mg,
21.8 μmol, 63%, α/β = >95/5): [α]2D8 +41.2 (c 1.32, CHCl3); 1H
NMR (400 MHz, CD2Cl2) δ 6.93–8.05 (m, 49H, aromatic), 5.41
3-O-Benzyl-4-O-chloroacetyl-2-deoxy-6-O-naphthylmethyl-2-
(2,2,2-trichloroethoxycarbonylamino)-α-D-glucopyranosyl)-
(1 → 4)-(methyl 2-O-benzoyl-3-O-benzyl-D-
glucopyranosyluronate) (17)
To a stirred solution of 16 (308 mg, 0.270 mmol) in acetone (d, 1H, J = 3.9 Hz), 5.37–5.41 (m, 1H), 5.16–5.32 (m, 5H), 5.07
(3.00 mL) and H2O (0.300 mL) was added NBS (72.5 mg, (s, 2H, A), 5.02 (d, 1H, J = 12.6 Hz), 5.01 (d, 1H, J = 11.6 Hz),
0.405 mmol) at 0 °C. After being stirred at the same tempera- 4.75 (d, 1H, J = 12.1 Hz), 4.68 (d, 1H, J = 11.6 Hz), 4.51–4.64
ture for 1 h, to the reaction mixture was added NBS (72.5 mg, (m, 12H), 4.35 (d, 1H, J = 10.6 Hz), 4.21 (d, 1H, J = 11.1 Hz),
0.405 mmol) at 0 °C. After being stirred at the same tempera- 4.02–4.13 (m, 4H), 3.85–3.91 (m, 3H), 3.67–3.83 (m, 6H), 3.64
ture for another 1 h, the reaction mixture was poured into a (s, 3H), 3.56–3.61 (m, 3H), 3.51 (d, 1H, J = 10.6 Hz), 3.34–3.42
mixture of saturated aq. NaHCO3 and 10% aq. Na2S2O3 with (m, 2H), 3.25 (s, 3H), 3.20–3.23 (m, 2H), 2.98 (t, 2H, J2 = 6.3
cooling. The aqueous layer was extracted with two portions of Hz), 1.06–1.47 (m, 8H); 13C NMR (100 MHz, CD2Cl2) δ 168.8,
ethyl acetate. The combined extract was washed with saturated 168.4, 166.2, 165.2, 164.8, 156.5, 154.4 × 2, 139.1, 138.3, 137.5,
aq. NaHCO3 and saturated aq. Na2S2O3 and brine, dried over 137.2, 137.0, 136.4, 135.7, 134.1, 133.8, 133.7, 133.6, 133.5,
Na2SO4, filtered and evaporated in vacuo. The residue was puri- 133.4, 130.0, 129.9 × 2, 129.3, 129.1, 128.9, 128.8, 128.7, 128.6,
fied by column chromatography on silica gel (elution with 128.4, 128.3, 128.0 × 2, 127.7, 127.5, 127.0, 126.8, 126.5, 126.3
hexane : ethyl acetate = 87 : 13) to give 17 (210 mg, 0.706 mmol, × 2 (101.5, 100.4, 98.4, 98.0 anomeric), 95.8, 82.6, 82.5, 77.9,
1
74%, α/β = >95/5) as an anomeric mixture; H NMR (400 MHz, 77.8, 77.8, 76.9, 75.3 × 2, 75.2, 75.0, 74.9, 74.8, 74.7 × 2, 74.5,
CD2Cl2) δ 7.12–8.06 (m, 22H, aromatic), 5.61 (dd, 1H, J = 3.9, 74.4, 74.1, 74.0, 73.9, 73.8, 72.9, 71.5, 70.4, 69.9, 69.3, 67.3,
3.9 Hz), 5.41 (d, 1H, J = 10.1 Hz), 5.40 (d, 1H, J = 3.9 Hz), 5.25 66.6, 55.0, 54.9, 53.0, 52.5, 41.1, 30.0, 29.5, 26.5, 25.8; IR (KBr)
(dd, 1H, J = 9.7, 9.7 Hz), 5.17 (dd, 1H, J = 3.9, 9.2 Hz), 4.82 (d, 3029, 2951, 1736, 1512, 1264, 1070, 1041, 821, 755 (cm−1);
1H, J = 11.1 Hz), 4.75 (d, 1H, J = 12.1 Hz), 4.74 (d, 1H, J = 11.6 HRMS (ESI-TOF) calcd for
Hz), 4.58–4.70 (m, 4H), 4.53 (d, 1H, J = 11.1 Hz), 4.47 (d, 1H, 2226.5385, found 2226.5374.
J = 11.6 Hz), 3.37 (dd, 1H, J = 8.2, 9.2 Hz), 4.22 (dd, 1H, J = 8.2,
C112H115N3O30Cl7 [M +
H]+
N-Benzyloxycarbonyl-6-aminohexyl 3-O-benzyl-2-deoxy-6-O-
naphthylmethyl-2-(2,2,2-trichloroethoxycarbonylamino)-
α-D-glucopyranosyl-(1 → 4)-(methyl 2-O-benzoyl-3-O-benzyl-
β-D-glucopyranosyluronate)-(1 → 4)-3-O-benzyl-2-deoxy-6-O-
naphthylmethyl-2-(2,2,2-trichloroethoxycarbonylamino)-
α-D-glucopyranosyl-(1 → 4)-(methyl 2-O-benzoyl-3-O-benzyl-
β-D-glucopyranosyluronate) (6)
8.7 Hz), 4.06 (ddd, 1H, H-2′, J = 3.9, 10.1, 10.6 Hz), 3.71–3.82
(m, 3H), 3.68 (s, 3H), 3.55–3.67 (m, 4H); 13C NMR (100 MHz,
CD2Cl2) δ 169.7, 166.3, 165.9, 154.4, 138.3, 137.6, 135.7, 133.9,
133.6, 133.4, 130.1, 129.7, 129.3, 129.0, 128.8, 128.7, 128.5,
128.4, 128.2 × 3, 128.1 × 2, 128.0, 127.9, 126.5, 126.3 (98.9, 95.8
anomeric), 90.8, 78.4, 78.1, 77.9, 75.9, 74.9, 74.5, 74.1, 73.7,
72.9, 71.3, 69.8, 69.3, 53.0, 41.1; IR (KBr) 3359, 2926, 1736,
1523, 1271, 1063, 754, 713 (cm−1); HRMS (ESI-TOF) calcd for To a stirred solution of 20 (2.54 g, 1.14 mmol) in DMF
C50H50NO15Cl4 [M + H]+ 1044.1956, found 1044.1935.
(22.8 mL) was added thiourea (260 mg, 3.42 mmol) and 2,6-
lutidine (158 μL, 1.37 mmol) at room temperature. After being
stirred at 50 °C for 12 h, the reaction mixture was poured into
ice-cooled 1 M HCl. The aqueous layer was extracted with two
portions of ethyl acetate. The combined extract was washed
with 1 M HCl, saturated aq. NaHCO3, and brine, dried over
Na2SO4, filtered and evaporated in vacuo. The residue was puri-
fied by MPLC (elution with toluene : ethyl acetate = 88 : 12 to
78 : 22) to give 6 (2.36 g, 1.09 mmol, 96%): [α]2D6 +42.2 (c 1.08,
N-Benzyloxycarbonyl-6-aminohexyl 3-O-benzyl-4-O-
chloroacetyl-2-deoxy-6-O-naphthylmethyl-2-(2,2,2-
trichloroethoxycarbonylamino)-α-D-glucopyranosyl-(1 → 4)-
(methyl 2-O-benzoyl-3-O-benzyl-β-D-glucopyranosyluronate)-
(1 → 4)-3-O-benzyl-2-deoxy-6-O-naphthylmethyl-2-(2,2,2-
trichloroethoxycarbonylamino)-α-D-glucopyranosyl-(1 → 4)-
(methyl 2-O-benzoyl-3-O-benzyl-β-D-glucopyranosyluronate)
(20)
1
CHCl3); H NMR (400 MHz, CD2Cl2) δ 6.90–8.04 (m, 49H, aro-
A mixture of 16 (59.2 mg, 52.0 μmol, 1.50 equiv.), 18 (41.7 mg, matic), 5.41 (d, 1H, J = 3.9 Hz), 5.32–5.35 (m, 1H), 5.24 (d, 1H,
34.7 μmol) and pulverized activated MS-4A (140 mg) in dry J = 2.9 Hz), 5.16–5.24 (m, 3H), 5.07 (s, 2H), 5.02 (d, 1H, J = 12.6
CH2Cl2 (1.00 mL) was stirred at room temperature for 30 min Hz), 5.00 (d, 1H, J = 11.1 Hz), 4.82 (d, 1H, J = 11.6 Hz), 4.78 (d,
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1H, J = 12.1 Hz), 4.70–4.74 (m, 3H), 4.62 (d, 1H, J = 12.1 Hz), J = 10.6 Hz), 4.05–4.14 (m, 4H), 3.86–3.93 (m, 3H), 3.75–3.81
4.50–4.57 (m, 8H), 4.34 (d, 1H, J = 10.6 Hz), 4.16 (d, 1H, J = (m, 4H), 3.68–3.73 (m, 2H), 3.66 (s, 3H), 3.57–3.64 (m, 2H),
11.1 Hz), 4.04–4.13 (m, 3H), 3.82–3.95 (m, 6H), 3.66–3.79 (m, 3.53 (d, 1H, J = 10.1 Hz), 3.40 (dd, 1H, J = 9.2, 10.6 Hz), 3.28 (s,
4H), 3.63 (s, 3H), 3.54–3.59 (m, 1H), 3.45–3.50 (m, 2H), 3H), 3.20–3.25 (m, 2H); 13C NMR (100 MHz, CD2Cl2) δ 168.4,
3.34–3.41 (m, 2H), 3.24 (s, 3H), 3.14–3.21 (m, 2H), 3.05 (d, 1H, 168.3, 166.2, 165.2, 164.7, 154.4 × 2, 139.0, 138.2, 136.9, 136.3,
J = 1.9 Hz), 2.98 (t, 2H, J = 6.7 Hz), 1.05–1.48 (m, 8H, aliphatic); 135.7, 134.1, 133.9, 133.8, 133.6, 133.5, 133.4, 132.7, 132.6,
13C NMR (100 MHz, CD2Cl2) δ 168.8, 168.4, 165.2, 164.7, 162.7, 130.1, 129.9, 129.7, 129.3 × 2, 129.1, 128.9, 128.8, 128.7, 128.6,
156.5, 154.5, 139.1, 139.0, 137.5, 137.2, 137.1, 136.3, 135.8, 128.5 × 3, 128.4, 128.3, 128.2 × 2, 128.1, 128.0 × 2, 127.8, 127.7,
134.0, 133.8, 133.7, 133.6, 133.5, 133.4, 130.0, 129.9 × 2, 129.3, 127.5, 127.1, 127.0 × 2, 126.9, 126.8, 126.5, 126.3 × 2, 126.2
129.0, 128.9 × 2, 128.8, 128.7 × 2, 128.6 × 2, 128.5, 128.3 × 2, (100.3, 98.3, 98.0, 95.7 anomeric), 87.4, 84.0, 82.5, 78.1, 77.9,
128.2, 128.1, 128.0, 127.8, 127.6, 127.1, 127.0, 126.8, 126.5, 77.8, 77.6, 76.8, 75.3, 75.2 × 2, 74.9 × 2, 74.6, 74.4, 74.1, 74.0,
126.3, 126.1 (101.5, 100.4, 98.7, 98.0 anomeric), 95.9, 95.8, 82.6 73.7, 72.9, 72.3, 71.5, 69.8, 69.2, 67.2, 55.0, 54.8, 53.0, 52.6,
× 2, 79.8, 77.9, 77.7, 76.8, 75.2, 74.9, 74.8, 74.7 × 2, 74.5, 74.4, 41.1; IR (KBr) 2920, 2850, 1736, 1509, 1262, 1069, 753, 711
74.2, 74.0, 73.9, 73.8, 72.9, 71.5, 71.2, 70.5, 70.4, 67.2, 66.6, (cm−1); HRMS (ESI-TOF) calcd for C104H100N2O27SCl7 [M + H]+
54.8 × 2, 53.0, 52.5, 41.2, 36.5, 31.4, 30.0, 29.5, 26.5, 25.8; 2085.4054, found 2085.4004.
IR (KBr) 3431, 3018, 2946, 1736, 1509, 1265, 1091, 768, 711
N-Benzyloxycarbonyl-6-aminohexyl 3-O-benzyl-4-O-
chloroacetyl-2-deoxy-6-O-naphthylmethyl-2-(2,2,2-
trichloroethoxycarbonylamino)-α-D-glucopyranosyl-(1 → 4)-
(cm−1); HRMS (ESI-TOF) calcd for C110H117N4O29Cl6 [M +
NH4]+ 2167.5935, found 2167.5945.
Phenylthio 3-O-benzyl-4-O-chloroacetyl-2-deoxy-6-O-
naphthylmethyl-2-(2,2,2-trichloroethoxycarbonylamino)-
α-D-glucopyranosyl-(1 → 4)-(methyl 2-O-benzoyl-3-O-benzyl-
β-D-glucopyranosyluronate)-(1 → 4)-3-O-benzyl-2-deoxy-6-O-
naphthylmethyl-2-(2,2,2-trichloroethoxycarbonylamino)-
α-D-glucopyranosyl-(1 → 4)-(methyl 2-O-benzoyl-3-O-benzyl-
β-D-glucopyranosyluronate) (5)
(methyl 2-O-benzoyl-3-O-benzyl-β-D-glucopyranosyluronate)-
(1 → 4)-3-O-benzyl-2-deoxy-6-O-naphthylmethyl-2-(2,2,2-
trichloroethoxycarbonylamino)-α-D-glucopyranosyl-(1 → 4)-
(methyl 2-O-benzoyl-3-O-benzyl-β-D-glucopyranosyluronate)-
(1 → 4)-3-O-benzyl-2-deoxy-6-O-naphthylmethyl-2-(2,2,2-
trichloroethoxycarbonylamino)-α-D-glucopyranosyl-(1 → 4)-
(methyl 2-O-benzoyl-3-O-benzyl-β-D-glucopyranosyluronate)-
(1 → 4)-3-O-benzyl-2-deoxy-6-O-naphthylmethyl-2-(2,2,2-
trichloroethoxycarbonylamino)-α-D-glucopyranosyl-(1 → 4)-
(methyl 2-O-benzoyl-3-O-benzyl-β-D-glucopyranosyluronate)
(25)
To a stirred solution of 17 (1.33 g, 1.20 mmol) in dry CH2Cl2
(3.5 mL) was added Cs2CO3 (390 mg, 1.20 mmol) and CCl3CN
(1.70 g, 12.0 mmol, 10.0 equiv.) at room temperature. After
being stirred at the same temperature for 12 h, the reaction
mixture was filtered through a pad of Celite®. The residue was A mixture of 5 (937 mg, 449 μmol), 6 (600 mg, 299 μmol) and
briefly purified by column chromatography on a small amount pulverized activated MS-4A (1.2 g) in dry CH2Cl2 (6.0 mL) was
of silica gel (elution with CHCl3 : MeOH = 98 : 2) and used for stirred at room temperature for 30 min under argon to remove
the next reaction without further purification. A mixture of the trace amounts of water. Then the reaction mixture was cooled
residue, 8 (850 mg, 801 μmol) and pulverized activated MS-4A to −40 °C. NIS (166 mg, 738 μmol) and TfOH (8.21 μL,
(3.2 g) in dry CH2Cl2 (16.0 mL) was stirred at room temperature 92.2 μmol) were added to the reaction mixture at the same
for 30 min under argon to remove trace amounts of water. temperature. After being stirred at −20 °C for 2 h, the reaction
Then the reaction mixture was cooled to −40 °C. TMSOTf mixture was neutralized with NEt3 and filtered through a pad
(14.5 μL, 80.1 μmol) was added to the reaction mixture at the of Celite®. The filtrate mixture was poured into a mixture of
same temperature. After being stirred at −20 °C for 1 h, the saturated aq. NaHCO3 and 10% aq. Na2S2O3 with cooling. The
reaction mixture was neutralized with NEt3 and filtered aqueous layer was extracted with two portions of ethyl acetate.
through a pad of Celite®. The filtrate mixture was poured into The combined extract was washed with saturated aq. NaHCO3
a mixture of saturated aq. NaHCO3 and 10% aq. Na2S2O3 with and 10% aq. Na2S2O3 and brine, dried over Na2SO4, filtered
cooling. The aqueous layer was extracted with two portions of and evaporated in vacuo. The residue was purified by MPLC
ethyl acetate. The combined extract was washed with saturated (elution with toluene : ethyl acetate = 90 : 10 to 80 : 20) and by
aq. NaHCO3 and 10% aq. Na2S2O3 and brine, dried over gel permeation chromatography (GPC) to give 25 (890 mg,
Na2SO4, filtered and evaporated in vacuo. The residue was puri- 206 μmol, 69%, α/β = >95/5): [α]2D8 +52.3 (c 0.30, CHCl3);
fied by MPLC (elution with toluene : ethyl acetate = 90 : 10 to 1H NMR (400 MHz, CD2Cl2) δ 6.79–8.13 (m, 93H, aromatic),
80 : 20) and by gel permeation chromatography (GPC) to give 5 5.39 (d, 1H, J = 12.6 Hz), 5.37 (d, 1H, J = 3.9 Hz), 5.27–5.32 (m,
(1.08 g, 519 μmol, 65% based on 8, α/β = >95/5): [α]2D9 +30.0 4H), 5.23 (d, 1H, J = 3.4 Hz), 5.00–5.19 (m, 11H), 4.95 (d, 1H,
(c 0.12, CHCl3); 1H NMR (400 MHz, CD2Cl2) δ 6.95–8.07 (m, J = 11.6 Hz), 4.88 (d, 1H, J = 11.6 Hz), 4.76 (d, 1H, J = 12.1 Hz),
49H, aromatic), 5.42 (d, 1H, J = 3.4 Hz), 5.41 (d, 1H, J = 7.2 Hz), 4.68 (d, 1H, J = 12.1 Hz), 4.46–4.66 (m, 20H), 4.44 (d, 1H, J =
5.29–5.33 (m, 2H), 5.23–5.29 (m, 2H), 5.17 (d, 1H, J = 10.1 Hz), 11.6 Hz), 4.32–4.37 (m, 2H), 4.29 (d, 1H, J = 7.7 Hz), 4.19–4.25
5.05 (d, 1H, J = 12.1 Hz), 5.03 (d, 1H, J = 11.6 Hz), 4.83 (d, 1H, (m, 3H), 4.06–4.14 (m, 4H), 3.74–4.02 (m, 14H), 3.72–3.56 (m,
J = 10.1 Hz), 4.78 (d, 1H, J = 12.1 Hz), 4.70 (d, 1H, J = 12.1 Hz), 9H), 3.43–3.52 (m, 5H), 3.29–3.40 (m, 4H), 3.11–3.26 (m, 13H),
4.53–4.65 (m, 11H), 4.36 (d, 1H, J = 11.1 Hz), 4.22 (d, 1H, 2.92–3.00 (m, 3H), 2.89 (dd, 1H, H-3c, J = 9.2, 9.7 Hz),
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1.07–1.49 (m, 8H, aliphatic); 13C NMR (100 MHz, CD2Cl2) δ 52.4, 41.1, 30.0, 29.9; IR (KBr) 3425, 3030, 2952, 1736, 1511,
168.8, 168.4, 168.3 × 2, 166.2, 165.2, 164.7 × 2, 156.5, 154.5 × 2, 1264, 1070, 755, 711 (cm−1).
154.4, 139.1, 139.0 × 2, 138.3, 137.5, 137.2, 137.0, 136.4, 136.2,
N-Benzyloxycarbonyl-6-aminohexyl 3-O-benzyl-4-O-
chloroacetyl-2-deoxy-6-O-naphthylmethyl-2-(2,2,2-
trichloroethoxycarbonylamino)-α-D-glucopyranosyl-(1 → 4)-
(methyl 2-O-benzoyl-3-O-benzyl-β-D-glucopyranosyluronate)-
(1 → 4)-3-O-benzyl-2-deoxy-6-O-naphthylmethyl-2-(2,2,2-
trichloroethoxycarbonylamino)-α-D-glucopyranosyl-(1 → 4)-
(methyl 2-O-benzoyl-3-O-benzyl-β-D-glucopyranosyluronate)-
(1 → 4)-3-O-benzyl-2-deoxy-6-O-naphthylmethyl-2-(2,2,2-
trichloroethoxycarbonylamino)-α-D-glucopyranosyl-(1 → 4)-
(methyl 2-O-benzoyl-3-O-benzyl-β-D-glucopyranosyluronate)-
(1 → 4)-3-O-benzyl-2-deoxy-6-O-naphthylmethyl-2-(2,2,2-
trichloroethoxycarbonylamino)-α-D-glucopyranosyl-(1 → 4)-
(methyl 2-O-benzoyl-3-O-benzyl-β-D-glucopyranosyluronate)-
135.7, 134.2, 134.1 × 2, 133.8, 133.7 × 2, 133.6, 133.5 × 2, 133.4,
130.0, 129.9 × 2, 129.8, 129.3, 129.2, 129.1, 129.0, 128.9 × 2,
128.8, 128.7, 128.6, 128.5, 128.4 × 2, 128.3, 128.2, 128.1 × 2,
128.0 × 2, 127.9, 127.8 × 2, 127.7 × 2, 127.5, 127.1 × 2, 127.0,
126.9, 126.8, 126.5, 126.3 × 2 (101.5, 100.4, 100.2, 98.3, 98.2,
98.0, 95.8, 95.7 anomeric), 82.8 × 2, 82.6, 77.7, 77.5, 77.4, 76.9,
76.7, 76.6, 75.6, 75.3, 75.2, 75.0, 74.9, 74.8, 74.7, 74.5, 74.4,
74.3, 74.1, 74.0, 73.9 × 3, 73.7, 72.9, 71.5, 71.4, 70.4, 69.9, 69.2,
67.2, 67.0, 66.6, 55.0, 54.8, 53.1, 52.5, 52.4 × 2, 41.2, 30.0, 29.5,
26.6, 25.8; IR (KBr) 3019, 2929, 1736, 1509, 1264, 1219, 1042,
769, 711 (cm−1).
N-Benzyloxycarbonyl-6-aminohexyl 3-O-benzyl-2-deoxy-6-O-
naphthylmethyl-2-(2,2,2-trichloroethoxycarbonylamino)-
α-D-glucopyranosyl-(1 → 4)-(methyl 2-O-benzoyl-3-O-benzyl-
β-D-glucopyranosyluronate)-(1 → 4)-3-O-benzyl-2-deoxy-6-O-
naphthylmethyl-2-(2,2,2-trichloroethoxycarbonylamino)-
α-D-glucopyranosyl-(1 → 4)-(methyl 2-O-benzoyl-3-O-benzyl-
β-D-glucopyranosyluronate)-(1 → 4)-3-O-benzyl-2-deoxy-6-O-
naphthylmethyl-2-(2,2,2-trichloroethoxycarbonylamino)-
α-D-glucopyranosyl-(1→4)-(methyl 2-O-benzoyl-3-O-benzyl-
β-D-glucopyranosyluronate)-(1→4)-3-O-benzyl-2-deoxy-6-O-
naphthylmethyl-2-(2,2,2-trichloroethoxycarbonylamino)-
α-D-glucopyranosyl-(1→4)-(methyl 2-O-benzoyl-3-O-benzyl-
β-D-glucopyranosyluronate) (26)
(1 → 4)-3-O-benzyl-2-deoxy-6-O-naphthylmethyl-2-(2,2,2-
trichloroethoxycarbonylamino)-α-D-glucopyranosyl-(1 → 4)-
(methyl 2-O-benzoyl-3-O-benzyl-β-D-glucopyranosyluronate)-
(1 → 4)-3-O-benzyl-2-deoxy-6-O-naphthylmethyl-2-(2,2,2-
trichloroethoxycarbonylamino)-α-D-glucopyranosyl-(1 → 4)-
(methyl 2-O-benzoyl-3-O-benzyl-β-D-glucopyranosyluronate)
(27)
A mixture of 5 (102.1 mg, 48.9 μmol), 26 (132 mg, 32.6 μmol)
and pulverized activated MS-4A (130 mg) in dry CH2Cl2
(1.0 mL) was stirred at room temperature for 30 min under
argon to remove trace amounts of water. Then the reaction
mixture was cooled to −40 °C. NIS (12.5 mg, 55.4 μmol) and
TfOH (0.87 μL, 9.78 μmol) were added to the reaction mixture
To a stirred solution of 25 (890 mg, 206 μmol) in DMF at the same temperature. After being stirred at −20 °C for 2 h,
(4.0 mL) was added thiourea (47.0 mg, 618 μmol) and 2,6-luti- the reaction mixture was neutralized with NEt3 and filtered
dine (28.5 μL, 247 μmol) at room temperature. After being through a pad of Celite®. The filtrate mixture was poured into
stirred at 50 °C for 12 h, the reaction mixture was poured into a mixture of saturated aq. NaHCO3 and 10% aq. Na2S2O3 with
ice-cooled 1 M HCl. The aqueous layer was extracted with two cooling. The aqueous layer was extracted with two portions of
portions of ethyl acetate. The combined extract was washed ethyl acetate. The combined extract was washed with saturated
with 1 M HCl, saturated aq. NaHCO3, and brine, dried over aq. NaHCO3 and 10% aq. Na2S2O3 and brine, dried over
Na2SO4, filtered and evaporated in vacuo. The residue was puri- Na2SO4, filtered and evaporated in vacuo. The residue was puri-
fied by MPLC (elution with toluene : ethyl acetate = 88 : 12 to fied by MPLC (elution with toluene : ethyl acetate = 90 : 10 to
78 : 22) to give 26 (795 mg, 196 μmol, 96%): [α]2D9 +47.6 (c 1.18, 80 : 20) and by gel permeation chromatography (GPC) to give
1
CHCl3); H NMR (400 MHz, CD2Cl2) δ 6.87–8.08 (m, 93H, aro- 27 (134 mg, 17.7 μmol, 68%, α/β = >95/5): [α]2D9 +56.8 (c 0.22,
matic), 5.44 (d, 1H, J = 2.9 Hz), 5.39 (d, 1H, J = 9.7 Hz), CHCl3); 1H NMR (400 MHz, CD2Cl2) δ 6.84–8.13 (m, 137H),
5.19–5.32 (m, 6H), 5.00–5.16 (m, 10H), 4.95 (d, 1H, J = 11.6 5.42 (d, 1H, J = 9.7 Hz), 5.39 (d, 1H, J = 3.4 Hz), 5.24–5.35 (m,
Hz), 4.88 (d, 1H, J = 11.6 Hz), 4.49–4.84 (m, 22H), 4.39–4.41 7H), 4.95–5.21 (m, 19H), 4.90 (d, 1H, J = 12.6 Hz), 4.81 (d, 1H,
(m, 2H), 4.35 (d, 1H, J = 7.7 Hz), 4.21–4.32 (m, 3H), 3.69–4.18 J = 13.0 Hz), 4.45–4.76 (m, 34H), 4.22–4.39 (m, 9H), 3.58–4.17
(m, 23H), 3.61–3.65 (m, 1H), 3.46–3.56 (m, 6H), 3.35–3.44 (m, (m, 35H), 3.29–3.54 (m, 15H), 3.09–3.27 (m, 24H), 2.90–3.02
4H), 3.17–3.27 (m, 16H), 2.95–3.03 (m, 4H), 1.15–1.52 (m, 8H); (m, 6H), 1.06–1.49 (m, 8H); 13C NMR (100 MHz, CD2Cl2)
13C NMR (100 MHz, CD2Cl2) δ 168.7, 168.4, 168.3 × 2, 166.2, δ 168.8, 168.4, 168.3 × 2, 166.2, 165.2, 164.7 × 2, 156.5, 154.5 × 2,
165.2, 164.7, 156.5, 154.5, 154.4, 139.1, 139.0, 138.9, 137.5, 154.4, 139.1, 139.0, 138.3, 137.5, 137.2, 137.0, 136.4, 136.2,
137.2, 137.1, 137.0, 136.2 × 2, 135.8, 134.1, 133.7 × 2, 133.6, 136.0, 135.7, 134.2, 134.1, 134.0, 133.8, 133.7, 133.6, 133.5 × 2,
133.5, 133.4, 130.0, 129.8, 129.3, 129.2, 129.0, 128.9, 128.8 × 2, 133.4, 130.0, 129.9, 129.8, 129.3, 129.2, 129.0, 128.9 × 2, 128.8,
128.7 × 2, 128.6, 128.5, 128.4, 128.3, 128.2, 128.1, 128.0, 127.9, 128.7, 128.6, 128.5, 128.4 × 2, 128.3, 128.2, 128.1, 128.0 × 2,
127.8, 127.7, 127.6, 127.5, 127.1 × 2, 126.9, 126.5, 126.3 (101.5, 127.9, 127.8 × 2, 127.7, 127.5, 127.1 × 2, 127.0, 126.9, 126.5,
100.4, 100.2, 98.7, 98.2, 98.0, 95.9, 95.8 anomeric), 82.8, 82.7 × 126.3 × 2 (101.5, 100.4, 100.2, 98.3, 98.2, 98.0, 95.8, 95.7
2, 82.6, 79.7, 77.6, 77.5, 77.4, 76.9, 76.6, 75.6, 75.2, 75.0, 74.9, anomeric), 82.8 × 2, 82.6, 77.8, 77.7, 77.5, 77.4, 76.9, 76.7, 75.6,
74.8, 74.7, 74.6, 74.5, 74.3, 74.1, 74.0, 73.9, 73.8 × 2, 72.9, 71.4, 75.3, 75.0, 74.9, 74.8, 74.7, 74.5 × 2, 74.4, 74.1, 74.0, 73.9, 73.8,
71.3, 70.4, 70.3, 67.1, 66.9, 66.6, 60.6, 54.8, 54.3, 53.0, 52.5, 73.7, 72.9, 71.5, 71.4, 70.4, 69.9, 69.3, 67.2, 66.9, 66.6, 55.0,
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54.9, 54.8, 53.1, 52.5, 52.4, 41.1, 30.0 × 2, 29.5, 26.5, 25.8, 14.3; was stirred at room temperature for 30 min under argon to
IR (KBr) 3028, 2952, 1736, 1510, 1264, 1070, 756, 711 (cm−1).
remove trace amounts of water. Then the reaction mixture was
cooled to 0 °C. CSA (2.4 mg, 10.4 μmol, 0.30 equiv.) was added
to the reaction mixture at 0 °C. After being stirred at the same
temperature for 1 h, the reaction mixture was filtered through
a pad of Celite®. The filtrate was evaporated in vacuo. The
residue was purified by MPLC (elution with toluene : ethyl
acetate = 88 : 12 to 75 : 25) to give 29 (189 mg, 317 μmol, 91%):
1H NMR (400 MHz, CDCl3) δ 6.74–8.05 (m, 548H, aromatic),
5.99 (t, 1H, J = 6.3 Hz), 5.63 (t, 1H, J = 6.3 Hz), 5.39–5.50 (m,
5H), 5.14–5.35 (m, 28H), 4.65–5.12 (m, 90H), 4.18–4.63 (m,
116H), 2.85–4.15 (m, 351H), 1.01–2.20 (m, 88H); 19F NMR
(373 MHz, CDCl3) δ −112.4, −120.0, −120.2, −121.0, −121.6,
−124.4; IR (KBr) 3423, 2951, 1752, 1452, 1264, 1041, 756, 710
(cm−1).
N-Benzyloxycarbonyl-6-aminohexyl 3-O-benzyl-2-deoxy-6-O-
naphthylmethyl-2-(2,2,2-trichloroethoxycarbonylamino)-
α-D-glucopyranosyl-(1 → 4)-(methyl 2-O-benzoyl-3-O-benzyl-
β-D-glucopyranosyluronate)-(1 → 4)-3-O-benzyl-2-deoxy-6-O-
naphthylmethyl-2-(2,2,2-trichloroethoxycarbonylamino)-
α-D-glucopyranosyl-(1 → 4)-(methyl 2-O-benzoyl-3-O-benzyl-
β-D-glucopyranosyluronate)-(1 → 4)-3-O-benzyl-2-deoxy-6-O-
naphthylmethyl-2-(2,2,2-trichloroethoxycarbonylamino)-
α-D-glucopyranosyl-(1 → 4)-(methyl 2-O-benzoyl-3-O-benzyl-
β-D-glucopyranosyluronate)-(1 → 4)-3-O-benzyl-2-deoxy-6-O-
naphthylmethyl-2-(2,2,2-trichloroethoxycarbonylamino)-
α-D-glucopyranosyl-(1 → 4)-(methyl 2-O-benzoyl-3-O-benzyl-
β-D-glucopyranosyluronate)-(1 → 4)-3-O-benzyl-2-deoxy-6-O-
naphthylmethyl-2-(2,2,2-trichloroethoxycarbonylamino)-
α-D-glucopyranosyl-(1 → 4)-(methyl 2-O-benzoyl-3-O-benzyl-
β-D-glucopyranosyluronate)-(1 → 4)-3-O-benzyl-2-deoxy-6-O-
naphthylmethyl-2-(2,2,2-trichloroethoxycarbonylamino)-
α-D-glucopyranosyl-(1 → 4)-(methyl 2-O-benzoyl-3-O-benzyl-
β-D-glucopyranosyluronate) (28)
6-O-Sulfated dodecamer attached with a fluorous tag (30)
To a stirred solution of 29 (148 mg, 24.2 μmol) in CH2Cl2
(2.5 mL) and saturated aq. NaHCO3 (0.5 mL) was added DDQ
(55.0 mg, 242 μmol) at 0 °C. After being stirred at 0 °C for 1 h,
to the reaction mixture was added DDQ (55.0 mg, 242 μmol) at
0 °C. After being stirred at 0 °C for another 1 h, to the reaction
To a stirred solution of 27 (125 mg, 20.7 μmol) in DMF mixture was added DDQ (55.0 mg, 242 μmol) at 0 °C. After
(0.50 mL) was added thiourea (5.0 mg, 62.1 μmol) and 2,6-luti- being stirred at 0 °C for another 1 h, the reaction mixture was
dine (3.0 μL, 24.8 μmol) at room temperature. After being filtered through a pad of Celite®. The filtrate mixture was
stirred at 50 °C for 12 h, the reaction mixture was poured into poured into saturated aq. NaHCO3 with cooling. The aqueous
ice-cooled 1 M HCl. The aqueous layer was extracted with two layer was extracted with two portions of ethyl acetate. The com-
portions of ethyl acetate. The combined extract was washed bined extract was washed with saturated aq. NaHCO3 and
with 1 M HCl, saturated aq. NaHCO3, and brine, dried over brine, dried over Na2SO4, filtered and evaporated in vacuo. The
Na2SO4, filtered and evaporated in vacuo. The residue was puri- residue was purified by MPLC (elution with toluene : ethyl
fied by MPLC (elution with toluene : ethyl acetate = 88 : 12 to acetate = 90 : 10 to 75 : 25) to give glucopyranoside-linking-
78 : 22) to give 28 (115 mg, 19.3 μmol, 93%): [α]3D1 +46.1 (c 0.08, fluorous tag. To a stirred solution of the residue in dry DMF
1
CHCl3); H NMR (400 MHz, CD2Cl2)δ 6.82–8.04 (m, 137H, aro- (2.5 mL) was added SO3·NEt3 (450 mg) and NEt3 (120 μL) at
matic), 5.38 (d, 1H, J = 3.4 Hz), 5.34 (d, 1H, J = 6.8 Hz), room temperature. After being stirred at 50 °C for 24 h, the
5.23–5.32 (m, 6H), 4.94–5.20 (m, 19H), 4.89 (d, 1H, J = 12.1 reaction mixture was neutralized with 5% aq. NaHCO3 and
Hz), 4.83 (d, 1H, J = 12.1 Hz), 4.77 (d, 1H, J = 11.6 Hz), evaporated in vacuo. The residue was purified by fluorous
4.47–4.75 (m, 31H), 4.45 (d, 1H, J = 11.1 Hz), 4.17–4.37 (m, column chromatography (Fluoro Flash® SPE) to give 30
9H), 3.65–4.12 (m, 32H), 3.59 (m, 1H), 3.29–3.51 (m, 16H), (81.7 mg, 13.3 μmol, 2 steps 55%): 1H NMR (400 MHz, CD3OD)
3.12–3.23 (m, 24H), 2.88–3.01 (m, 6H), 1.07–1.53 (m, 8H, δ 6.74–8.05 (m, 548H, aromatic), 5.24–5.53 (m, 16H), 4.93–5.22
aliphatic); 13C NMR (100 MHz, CD2Cl2) δ 168.8, 168.5, 168.3 × (m, 52H), 3.68–4.87 (m, 259H), 3.45–3.68 (m, 45H), 3.15–3.44
2, 165.2, 164.8, 164.7, 156.5, 154.5 × 2, 154.4, 139.1, 139.0 × 2, (m, 37H), 2.61–3.10 (m, 125H), 0.89–2.31 (m, 88H); 19F NMR
137.5, 137.2, 137.1, 137.0, 136.3, 136.2, 136.0, 135.8, 134.1 × 2, (373 MHz, CD3OD) δ −111.8, −119.4, −119.5, 120.4, −121.0,
133.8, 133.7, 133.6 × 2, 133.5, 133.4, 130.0, 129.9, 129.8, 129.3, −123.9; IR (KBr) 3427, 2956, 1730, 1453, 1218, 1064, 738, 712
129.2, 129.1, 129.0, 128.9, 128.8, 128.7, 128.6, 128.5, 128.4, (cm−1).
128.3, 128.2, 128.1, 128.0, 127.9, 127.8, 127.7, 127.6, 127.2,
127.1, 127.0, 126.9, 126.6, 126.4, 126.1 (101.5, 100.4, 100.2,
N- and 6-O-Sulfated dodecamer attached with a fluorous tag 31
98.7, 98.2, 98.0, 95.9, 95.8 anomeric), 82.8 × 2, 82.7, 82.6, 79.8, To a stirred solution of 30 (62.7 mg, 10.2 μmol) in CH2Cl2
77.9, 77.6, 77.5, 77.4, 76.9, 76.7, 75.6, 75.3, 75.0 × 2, 74.8, 74.7 (1.0 mL) and AcOH (50.0 μL) was added Zn dust (150 mg) at
× 2, 74.5 × 2, 74.4, 74.2, 74.1, 74.0, 73.9 × 2, 73.8, 73.1, 71.5, room temperature. After being stirred at the same temperature
71.4, 71.1, 70.6, 70.4, 67.2, 67.0, 66.6, 54.8, 52.5, 52.4, 41.2, for 1 h or 12 h, the reaction mixture was poured into ice-
30.1, 29.7, 29.5, 26.6, 25.8, 14.3; IR (KBr) 3426, 2927, 1736, cooled saturated aq. NaHCO3 and filtered through a pad of
1510, 1264, 1071, 758, 711 (cm−1).
Celite®. The filtrate was evaporated in vacuo. The residue was
purified by MPLC (elution with toluene : acetone : formic acid
= 93.75 : 6 : 0.25 to 79.75 : 20 : 0.25) and by reversed phase
Dodecamer attached with a fluorous tag 29
A mixture of 28 (207 mg, 34.8 μmol), 3 (32.1 mg, 52.2 μmol), HPLC (Develosil® ODS-UG-5 column, eluent: H2O–MeOH, gra-
and pulverized activated MS-4A (35 mg) in dry CH2Cl2 (1.0 mL) dient: 0.00 min [H2O] : [CH3CN]
=
30 : 70, 2.00 min
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[H2O] : [CH3CN] = 30 : 70, 12.0 min [H2O] : [CH3CN] = 10 : 90, 5.59–5.62 (m, 6H), 4.57–4.60 (d, 5H), 4.41–4.45 (m, 5H),
10 mL min−1) to give the amino derivative. To a stirred sol- 4.32–4.36 (m, 2H), 4.13–4.18 (m, 6H), 3.97–4.03 (m, 5H), 3.91
ution of the residue in dry DMF (1.0 mL) was added SO3·NEt3 (s, 3H), 3.64–3.89 (m, 37H), 3.61 (dd, 1H, J = 9.7, 13.0 Hz), 3.56
(181 mg) and NEt3 (50 μL) at room temperature. After being (dd, 1H, J = 9.2, 9.7 Hz), 3.46–3.53 (m, 1H), 3.34–3.39 (m, 5H),
stirred at room temperature for 24 h, the reaction mixture was 3.25–3.31 (m, 6H), 3.17–3.23 (m, 3H), 1.43–1.51 (m, 4H),
neutralized with 5% NaHCO3 aq. and evaporated in vacuo. The 1.22–1.31 (m, 4H); 13C NMR (100 MHz, D2O) δ 192.6, 175.1,
residue was purified by fluorous column chromatography 175.0, 171.2, 164.3, 129.0, 128.7, 114.5 (102.1, 101.9, 97.6, 97.2,
(Fluoro Flash® SPE) to give 31 (12.8 mg, 2.25 μmol, 2 steps 97.0 anomeric), 77.1, 76.9, 76.8, 76.7, 76.6, 76.5, 76.3, 75.9,
1
22%): H NMR (400 MHz, CD3OD) δ 6.90–8.18 (m, 548H, aro- 72.8 × 2, 72.6, 71.1, 70.4, 69.8, 69.6, 69.4, 69.0, 68.6 × 2, 66.3,
matic), 5.35–5.69 (m, 22H), 4.90–5.30 (m, 69H), 4.29–4.79 (m, 65.8, 58.0, 57.5, 55.8, 39.7, 32.7, 29.0, 28.6, 28.0, 25.5, 24.9,
113H), 3.55–4.25 (m, 165H), 3.35–3.54 (m, 49H), 3.12–3.25 (m, 24.6; IR (KBr) 3437, 2926, 1606, 1418, 1227, 1046, 941, 636
32H), 2.70–3.00 (m, 46H), 0.86–2.37 (m, 88H); 19F NMR (cm−1); HRMS (ESI-TOF) calcd for C88H136N7O100S13 [M − H]−
(373 MHz, CD3OD) δ −111.8, −119.4, −119.5, 120.4, −121.0, 3306.2141, found 3306.2141.
−123.9; IR (KBr) 3449, 2926, 1728, 1454, 1260, 1035, 751, 716
(cm−1).
Notes and references
N-(S-(4-Methoxyphenylcarbonyl)thioacetyl)-6-aminohexyl 2-
deoxy-2-sulfoamino-6-O-sulfonate-α-D-glucopyranosyl-(1 → 4)-
1 I. Capila and R. J. Linhardt, Angew. Chem., Int. Ed., 2002,
β-D-glucopyranosyluronate-(1 → 4)-2-deoxy-2-sulfoamino-6-O-
41, 390.
sulfonate-α-D-glucopyranosyl-(1 → 4)-β-D-glucopyrano-
2 M. K. Furue, J. Na, J. P. Jackson, T. Okamoto, M. Jones,
D. Baker, R.-I. Hata, H. D. Moore, J. D. Sato and
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syluronate-(1 → 4)-2-deoxy-2-sulfoamino-6-O-sulfonate-α-D-
glucopyranosyl-(1 → 4)-β-D-glucopyranosyluronate-(1 → 4)-2-
deoxy-2-sulfoamino-6-O-sulfonate-α-D-glucopyranosyl-(1 → 4)-
3 (a) Y. Suda, K. Bird, T. Shiyama, S. Koshida, D. Marques,
β-D-glucopyranosyluronate-(1 → 4)-2-deoxy-2-sulfoamino-6-O-
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syluronate-(1 → 4)-2-deoxy-2-sulfoamino-6-O-sulfonate-α-D-
glucopyranosyl-(1 → 4)-β-D-glucopyranosyluronate (1)
To a stirred solution of 31 (11.5 mg, 2.02 μmol) in 1,4-dioxane
(0.60 mL) and H2O (0.30 mL) was added NaOMe (10.0 mg) at
room temperature. After being stirred at 35 °C for 24 h, the
reaction mixture was evaporated in vacuo. The residue was pur-
ified by size exclusion column chromatography on Sephadex
PD-10 to give carboxylate attached with a fluorous tag. The car-
boxylate was stirred in dry THF (0.500 mL) at room tempera-
ture for 5 min. Then liq. NH3 (4.5 mL) and Na (20.0 mg) were
added at −78 °C. After being stirred at the same temperature
for 30 min, the reaction mixture was quenched with NH4Cl.
After removal of liquid ammonia and the solvents in vacuo, the
residue was purified by size exclusion column chromatography
on Sephadex PD-10 to give the amino derivative. To a stirred
solution of the amino derivative in 1,4-dioxane (0.60 mL) and
H2O (0.30 mL) was added 4 (8.0 mg, 20.2 μmol) and NaHCO3
(10.0 mg) at room temperature. After being stirred at the same
temperature for 6 h, TFA (0.050 mL) was added to the reaction
mixture at 0 °C. After being stirred at the same temperature for
20 min, the reaction mixture was diluted with ethyl acetate
(10.0 mL) and H2O (5.0 mL). After being stirred at room temp-
erature for 5 min, the aqueous layer was quenched with
NaHCO3 aq. and evaporated in vacuo. To a stirred solution of
the residue in H2O (1.00 mL) was added DOWEX cation
exchange resin Na form (10.0 mg) at room temperature. After
being stirred at the same temperature for 5 min, the reaction
mixture was filtered and purified by size exclusion column
chromatography on Sephadex PD-10 to give 1 (4.40 mg,
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1
1.15 μmol, 57%): [α]2D3 +43.2 (c 0.22, H2O); H NMR (400 MHz,
D2O) δ 7.99 (d, 2H, J = 9.2 Hz), 7.10 (d, 2H, J = 9.2 Hz),
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