Synthesis of a new glycosphingolipid from the marine ascidian Microcosmus sulcatus using a one-pot glycosylation strategy

Article abstract of DOI:10.1016/j.tet.2012.12.023

A novel neutral glycosphingolipid found in Microcosmus sulcatus containing a β-d-Galp(1→4)[α-d-Fucp-(1→3)]β-d-Glcp-(1→)Cer motif was synthesized. Trisaccharide derivatives were synthesized using trimethylsilyltrifluoromethanesulfanate (TMSOTf) and N-iodosuccimide (NIS)/trifluoromethane sulfonic acid (TfOH) as the promoters. Synthesis was achieved with an efficient one-pot glycosylation strategy. This is the first report of a one-pot glycosylation strategy using the procedure of Boons et al. for the synthesis of a natural product. Coupling of trisaccharide derivative 19 and ceramide derivative 20 by TMSOTf afforded the glycosphingolipid derivative 21. The fully protected glycoside was deprotected to give the target glycosphingolipid 2.

Full text of DOI:10.1016/j.tet.2012.12.023

Tetrahedron 69 (2013) 1470e1475
Contents lists available at SciVerse ScienceDirect
Tetrahedron
journal homepage: www.elsevier.com/locate/tet
Synthesis of a new glycosphingolipid from the marine ascidian
Microcosmus sulcatus using a one-pot glycosylation strategy
,
b
a
a
Isao Ohtsuka a , Noriyasu Hada , Toshiyuki Atsumi , Nobuko Kakiuchi
*
a School of Pharmaceutical Sciences, Kyushu University of Health and Welfare, 1714-1 Yoshino-cho, Nobeoka city, Miyazaki 882-8508, Japan
b Faculty of Pharmacy, Keio University, 1-5-30 Shibakoen, Minato-ku, Tokyo 105-8512, Japan
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 28 October 2012
Received in revised form 6 December 2012
Accepted 10 December 2012
Available online 19 December 2012
A novel neutral glycosphingolipid found in Microcosmus sulcatus containing a b-D-Galp(1/4)[a-D-Fucp-
(1/3)]b-D-Glcp-(1/)Cer motif was synthesized. Trisaccharide derivatives were synthesized using tri-
methylsilyltrifluoromethanesulfanate (TMSOTf) and N-iodosuccimide (NIS)/trifluoromethane sulfonic
acid (TfOH) as the promoters. Synthesis was achieved with an efficient one-pot glycosylation strategy.
This is the first report of a one-pot glycosylation strategy using the procedure of Boons et al. for the
synthesis of a natural product. Coupling of trisaccharide derivative 19 and ceramide derivative 20 by
TMSOTf afforded the glycosphingolipid derivative 21. The fully protected glycoside was deprotected to
give the target glycosphingolipid 2.
Keywords:
Microcosmus sulcatus
Glycosphingolipids
Oligosaccharide synthesis
One-pot glycosylation strategy
Ó 2012 Elsevier Ltd. All rights reserved.
1. Introduction
Cer configuration (1). Their structures are unique because oligosac-
charides containing a D-fucose are not found in all mammals. Thus,
Glycosphingolipids such as gangliosides or cerebrosides are
ubiquitous in biologic systems and are involved in many important
processes, such as fertilization, embryogenesis, neuronal de-
velopment, hormone activity, cell proliferation, and tissue organi-
zation.1,2 The structures and biologic functions of many
gangliosides have been widely investigated and reported in various
reviews.3,4 The biologic functions of glycolipids lacking sialic acid in
various invertebrate animal species, however, are unknown.5 Elu-
cidation of the function of glycolipids in natural products will lead
to better understanding of their functional processes in animals, as
well as to molecular evolution in living organisms. Gaining
knowledge regarding their function will also help to uncover dis-
ease mechanisms and facilitate the development of new drugs.
These complex compounds are very difficult to isolate from nature,
however, and only small amounts can be obtained. Studies and
structurally well-defined glycolipids provided by organic synthesis
will advance the field of glycobiology.6e9
these compounds and their analogues may potentially exhibit new
biologic activity that will lead to better understanding of disease
mechanisms and the potential development of new drugs.11,12 The
biologic activities of these compounds cannot be compared with
those of glycosphingolipids from other animal species, because the
molecules contain different ceramide structures. Therefore, the
ceramide structures must also be controlled for functional studies of
the carbohydrate moieties in glycosphingolipids. The ceramides of
major natural glycosphingolipids comprise a fatty acid and a satu-
rated or unsaturated sphingosine.4,13 We are interested in the
structure of the trisaccharide of glycosphingolipids from M. sulcatus
and have attempted to synthesize these structures containing gen-
eral ceramides (2, Fig. 1). Synthesis of complex glycosphingolipids
requires many time- and labor-intensive reaction steps. These long
synthetic routes must be decreased to enhance the efficiency of ol-
igosaccharide synthesis, thereby providing many target compounds
to biochemical researchers. One-pot multistep approaches do not
require intermediate work-up and purification steps and thus ex-
pedite synthesis.13 Glycosylation strategies using one-pot multistep
approaches are highly efficient synthetic routes for complex
carbohydrates.14e17 Boons et al. recently reported the synthesis of
branched trisaccharide derivatives using a one-pot glycosylation
strategy18 that combines the reductive opening of a benzylidene
acetal and a trichloroacetimidate glycosylation. Their procedure had
not been previously used for natural product synthesis, and here we
report the first synthesis of a novel glycosphingolipid isolated from
Recently, Fattorusso et al. isolated and characterized a novel
neutral glycosphingolipid (1, Fig. 1) from the marine ascidian
Microcosmus sulcatus.10 The carbohydrate structure features a
D
-fu-
-galactose residue attached to the reducing-end of
glucose through a -Galp(1/4)[ -Fucp-(1/3)] -Glcp-(1/)
cose and a
D
D-
b-D
a-D
b-D
* Corresponding author. Tel.: þ81 982 23 5701; fax: þ81 982 23 5702; e-mail
address: ohtsuka@phoenix.ac.jp (I. Ohtsuka).
0040-4020/$ e see front matter Ó 2012 Elsevier Ltd. All rights reserved.
http://dx.doi.org/10.1016/j.tet.2012.12.023

I. Ohtsuka et al. / Tetrahedron 69 (2013) 1470e1475
1471
O
OH
OH
O
C20H41
HN
HN
C13H27
C13H27
HO
OH
OH
O
OH
O
HO
HO
O
O
O
O
HO
HO
HO
HO
O
C11H23
O
O
O
OH
OH
OH
OH
OH
OH
O
CH3
O
CH3
1
2
HO
HO
HO
HO
OH
OH
Fig. 1. Structure of glycosphingolipids 1 and 2 from Microcosmus sulcatus.
M. sulcatus based on the one-pot method recently reported by
Boons et al.
7.8 Hz (
d
¼4.69 ppm, d, 1H, H-10). The All group of compound 14 was
selectively removed by treatment with PdCl2 to form acceptor 15.
Next, disaccharide acceptor 15 was glycosylated with donor 10. The
synthesis of trisaccharide derivative 16 using acceptor 15 and donor
10 was achieved with N-iodosuccimide (NIS) and trifluoromethane
sulfonic acid (TfOH)26 in 72% yield (Scheme 2). Anomeric protons of
2. Results and discussion
2.1. Synthesis of monosaccharide, disaccharide, and tri-
saccharide derivatives
16 were observed at
d
¼5.76 (br s, 1H, H-100), 5.01 (d, 1H, J1,2¼7.4 Hz,
H-1), and 4.71 (d, 1H, J1,2¼7.8 Hz, H-10) in the 1H NMR spectrum.
Furthermore, C-1 atoms of Glcp, Galp, and Fucp were observed at
Compound 4 was synthesized from
b-D-glucopyranoside de-
d
¼102.7 (C-1), 98.8 (C-10), 95.9 (C-100) in the 13C NMR spectrum. The
rivative 319 by benzylation (90%) and converted to glycosyl acceptor
5 by ring opening of the benzylidene acetal group. The glucopyr-
anoside derivative 6 containing a free C-3 hydroxyl group for use in
the one-pot glycosylation was obtained by removing the allyl (All)
NMR data supported the structure of the trisaccharide. Tri-
saccharide derivative 16 in 37% overall yield was synthesized from
monosaccharide derivative 5.
group of 5 using PdCl2.20
D-Fucopyranoside derivatives were syn-
thesized according to the preparations reported by Kiso.21 Glycosyl
2.2. Synthesis of trisaccharide derivatives using a one-pot
glycosylation strategy
donor 10 containing acetyl (Ac) groups on O-2 and O-3 and a benzyl
(Bn) group on O-4 was obtained from phenyl 1-thio-
anoside (7), which was prepared by acetylation, thioglycosylation,
and deprotection of -fucose over three steps. The thiophenyl group
of 10 was converted to a trichloroacetimidate group because the
one-pot glycosylation required two types of trichloroacetimidate
donors: fucosylimidate and galactosylimidate derivatives. The
b-D-fucopyr-
In traditional approaches of oligosaccharide synthesis, the
product of a glycosylation reaction is isolated and subsequently
reacted to be suitable for the next glycosylation reaction. Reducing
the number of steps in this process would improve synthesis of the
target compound. A one-pot multistep strategy uses the product of
one glycosylation reaction directly in the next reaction, avoiding
the work-up and isolation steps of the intermediate glycoside. The
new glycosylation approach reported by Boons et al. combines the
reductive opening of a benzylidene acetal and trichloroacetimidate
glycosylation. This strategy is efficient for the synthesis of branched
trisaccharide derivatives. Using this method, glycosyl acceptor 6
and donor 12 were coupled by using TfOH as the glycosylation
promoter.27 The benzylidene acetal group of the synthesized di-
saccharide intermediate was opened using reductive conditions
with trimethylsilane and TfOH.28 This reaction gave a disaccharide
intermediate containing a free C-4 hydroxyl group on Glcp. Finally,
donor 13 was added to the reaction mixture at ꢀ78 ꢁC, and the
reaction mixture was allowed to warm to 0 ꢁC (Scheme 2). The
reaction progress was monitored by TLC. The trisaccharide de-
rivative was obtained in 47% yield using the one-pot glycosylation
strategy in three steps and identified as compound 16 by 1H NMR
and 13C NMR. This procedure proved very useful for the synthesis of
a branched trisaccharide, producing a higher yield than the tradi-
tional procedure.
D
a
and
group were obtained by treatment with N-bromosuccimide
(NBS),22 and trichloroacetimide derivative 12 (
b
isomers of 11 (
a
/
b
¼0.99:1.0) containing a free C-1 hydroxyl
a/
b¼1.0:0.25) for the
one-pot glycosylation was synthesized by addition of tri-
chloroacetonitrile and 1,8-diazabicyclo[5,4,0]-7-undecane (DBU)
(Scheme 1).
R4O
R1
O
CH3
O
R2O
R3O
R2O
OMP
R3O
OR3
OR1
R1
R2
H
R3
R1
H
R2
R3
CHPh
CHPh
Bn
CHPh
R4
7
SPh
H
3
4
5
6
All
All
All
H
a
b
c
d
8
SPh
SPh
SPh
OH
H
(CH3)2C
(CH3)2C
Ac
Bn
Bn
Bn
e
f
9
Bn
Bn
Bn
H
10
11
12
g
Ac
h
OC(NH)CCl3 Bn
Ac
Scheme 1. Reagents and conditions: (a) BnCl, NaH, DMF/THF, 90%; (b) HCl/Et2O,
NaCNBH3, THF, 78%; (c) PdCl2, AcONa, AcOH/H2O, 88%; (d) (CH3)2C(OCH3)2, CSA, DMF,
88%; (e) BnCl, NaH, DMF/THF, 89%; (f) (1) 90% AcOH; (2) Ac2O, py, 89% (two steps); (g)
NBS, acetone/H2O, 90%; (h) Cl3CCN, DBU, CH2Cl2, quant.
2.3. Synthesis of glycosphingolipid derivatives and target
compound 2
Subsequent removal of the Bn and Ac groups from 16 by cata-
lytic hydrogenolysis over 10% Pd/C in MeOH and AcOH (1:1),
treatment with NaOMe, followed by benzoylation gave 17 (58%
over three steps). Selective removal of the p-methoxy phenyl (MP)
group with ceric ammonium nitrate (CAN) in CH3CN and H2O
(6:1),29 and treatment with trichloroacetonitrile and DBU gave the
Disaccharide derivative 14 was synthesized using the tri-
chloroacetimidate method. Glycosyl acceptor
5 was treated
with donor 1323 using trimethylsilyltrifluoromethanesulfonate
(TMSOTf)24 as the glycosylation promoter. Thin layer chromatog-
raphy (TLC) revealed that purification of the mixture by silica gel
column chromatography afforded 14 (72%). The
b
-linkage was
corresponding a-trichloroacetimidate derivative 19. Glycosylation
confirmed by 1H NMR and 13C NMR spectrometry.25 The anomeric
protons of Galp appeared as a doublet with a coupling constant of
of (2S,3S,4R)-3,4-di-O-benzyl-2-hexadecanamido-octadecane-3,4-
diol (20)30 with glycosyl donor 19 was carried out in the presence

1472
I. Ohtsuka et al. / Tetrahedron 69 (2013) 1470e1475
5
OAc
OR2
BnO
R1O
O
O
O
O
AcO
AcO
R2O
R2O
c
a
R3
RO
OMP
O
O
O
AcO
AcO
OAc
O
R1
R2 R3
R4
H
OBn
R2O
R4
OAc
OR2
16 Bn Ac OMP
17 Bz Bz OMP
O
CH3
R
d
e
f
R1O
O
CCl3
H
14 All
15
10
R2O
OAc
13
OR2
b
18 Bz Bz
19 Bz Bz
OH H
H
NH
H
OC(NH)CCl3
13
O
BnO
Ph
6
O
O
O
HO
O
OMP
O
OMP
g-2)
g-1)
OBn
CH3
OBn
CH3
-78 C
1 hr
-78 C
1 hr
CH2Cl2
0 C
O
O
BnO
BnO
30 min
12
AcO
AcO
OAc
OAc
Scheme 2. Reagents and conditions: (a) TMSOTf, CH2Cl2, 72%; (b) PdCl2, AcONa, 90% AcOH, 75%; (c) NIS, TfOH, CH2Cl2, 72%; (d) (1) Pd/C, AcOH/MeOH; (2) NaOMe, MeOH; (3) BzCl,
py, 58% (three steps); (e) CAN, CH3CN/H2O, 77%; Cl3CCN, DBU, CH2Cl2, 81%; (g) (1) TfOH, CH2Cl2; (2) TfOH, Et3SiH, 47% (three steps).
of TMSOTf and type AW-300 molecular sieves to afford tri-
saccharide derivative 21 (41%). Removal of the Bn group from 21 by
catalytic hydrogenolysis over 10% Pd/C in CH2Cl2, MeOH, and AcOH
(1:1:1) gave 22 (90%). Finally, removal of the benzoyl (Bz) group of
(JEOL Ltd.) in CDCl3, D2O, and CD3OD with Me4Si as the internal
standard. High-resolution mass spectra were recorded on a JEOL
JMS-700 under FAB conditions. Iontrap-LCeMS spectra were
recorded on an LCO Advantage (Thermo-quest Ltd.). TLC
was performed on Silica Gel 60 F254 (E. Merck) with detection
by quenching UV fluorescence and charring with 10% H2SO4.
Column chromatography was performed on Silica Gel 60 (E.
Merck).
ꢀ
22 under Zemplen conditions and column chromatography using
a Sephadex LH-20 afforded target glycosphingolipid 2 (Scheme 3.).
The structure and purity of 2 were determined by 1H NMR and 13
C
NMR spectrometry and HR-FABMS data.
O
HN
C13H27
C13H27
19
OR2
OR1
R1O
O
O
R1O
R1O
O
O
O
a
O
R1
Bz
Bz
H
R2
Bn
H
OR1
OR2
OR1
HN
C13H27
O
CH3
21
22
2
OBn
R1O
b
c
R1O
HO
C13H27
20
OR1
H
OBn
Scheme 3. Reagents and conditions: (a) TMSOTf, CH2Cl2, 41%; (b) Pd/C, CH2Cl2/MeOH/AcOH, 90%; (c) NaOMe, MeOH/1,4-dioxane, 50%.
3. Conclusion
4.2. 4-Methoxyphenyl 3-O-allyl-2,6-di-O-benzyl-b-D-gluco-
pyranoside (5)
In summary, we achieved the first successful synthesis of a novel
glycosphingolipid from the marine ascidian M. sulcatus. The tri-
saccharide derivative was produced in good yield using both tra-
ditional procedures and a one-pot glycosylation strategy. This is the
first application of the one-pot glycosylation strategy combining
ꢁ
NaCNBH3 (1.0 M) in THF (3.2 mL, 32 mmol) and 3 A molecular
sieves (5.0 g) were added to a solution of 4 (2.0 g, 3.9 mmol) in
THF (15 mL), and the reaction mixture was stirred for 2 h at room
temperature. HCl in diethylether (50 mL) was then added, and the
reaction mixture was stirred for 1 h at room temperature. The
reaction mixture was filtered and extracted with CHCl3. The or-
ganic solvent was washed with aqueous NaHCO3, dried, and
concentrated to give a clear oil. The crude product was purified by
the reductive opening of
a benzylidene acetal and a tri-
chloroacetimidate glycosylation to the synthesis of a natural
product. The development of one-pot glycosylation strategies may
be a breakthrough for complex oligosaccharide synthesis.
silica gel column chromatography (toluene/acetone¼20:1 to 10:1)
25
4. Experimental
to give 5 (1.7 g, 83%) as a white solid. Mp 9699 ꢁC; [
a
]
ꢀ22.2 (c
D
1.1, CHCl3); 1H NMR (400 MHz, CDCl3, 300K):
d 7.35e6.78 (m, 14H,
4.1. General method
Phꢂ3), 5.93 (m, 1H, OCH2CH]CH2), 5.25 (dd, 2H, OCH2CH]CH2),
5.02, 4.80, 4.60, 4.57 (each d, 4H, PhCH2Oꢂ4), 4.86 (d, 1H,
J1,2¼7.8 Hz, H-1), 4.41 (dd, 1H, OCH2CH]CH2), 4.26 (dd, 1H,
OCH2CH]CH2), 3.83 (dd, 1H, H-6a), 3.76 (s, 3H, PhOCH3), 3.70 (dd,
1H, H-6b), 3.63 (t, 1H, H-2), 3.61 (t, 1H, H-4), 3.55 (q, 1H, H-5), 3.41
Melting points (mp) of compound 2, 5, 11, and 22 were ob-
tained with a Yanaco MP-J3. Optical rotations were measured
with a Jasco P-1020 digital polarimeter. 1H NMR and 13C NMR
spectra were recorded with a JMN AL 400 FT NMR spectrometer
(t, 1H, H-3); 13C NMR (400 MHz, CDCl3, 300 K):
d 155.1, 151.2, 138.0,

I. Ohtsuka et al. / Tetrahedron 69 (2013) 1470e1475
1473
137.7, 134.8, 128.3, 128.2, 128.0, 127.6, 127.5, 127.4, 118.3, 117.0,
102.7 (C-1), 83.7 (C-3), 84.4 (C-2), 74.8 (PhCH2O), 74.3 (PhCH2O),
74.2 (C-5), 73.6 (OCH2CH]CH2), 71.3 (C-4), 70.2 (C-6), 55.7
a
of
), 69.0 (C-4 of
a
b
), 64.6 (C-4 of
a
), 20.9, 20.8, 16.3 (C-6 of
b
), 16.1 (C-6
þ
); LCeMS (ESI) calcd for C17H23O7 (MþH)þ m/z 338.14; mea-
sured m/z 338.14.
þ
(PhOCH3); LCeMS (ESI) calcd for C30H35O6 (MþH)þ m/z 507.23;
measured m/z 507.23.
4.6. 3,4-Di-O-acetyl-2-O-benzyl-b-D-fucopyranosyltri-
chloroacetimidate (12)
4.3. 4-Methoxyphenyl 2-O-benzyl-4,6-O-benzylidene-b-D-glu-
copyranoside (6)
Cl3CCN (537 mL, 5.3
added to a solution of 11 (180 mg, 0.53 mmol) in CH2Cl2 (3.0 mL) at
0
ꢁC, and the mixture was stirred for 1 h. After completion of the
mmol) and DBU (119 mL, 0.8 mmol) were
AcONa (12 g) and PdCl2 (5.4 g) were added to a solution of 5
(2.1 g, 2.5 mmol) in AcOH (100 mL) and H2O (10 mL), and the re-
action mixture was stirred for 12 h at room temperature. The re-
action mixture was filtered, extracted with AcOEt, washed with
aqueous NaHCO3, dried, and concentrated. The crude product was
reaction, the mixture was concentrated. Column chromatography
of the residue on silica gel (hexane/AcOEt¼10:1, then 3:1) gave 12
25
(256 mg, quant.) as a colorless oil. [
a
]
D
þ96.3 (c 6.0, CHCl3); 1H
NMR (400 MHz, CDCl3, 300 K):
5H, Ph), 6.72 (d, 1H, H-1 of
2H, H-3 of , H-4 of ), 5.19 (d, 1H, H-4 of
4.89 (d,1H, PhCH2), 4.68, 4.65 (each d, 2H, PhCH2ꢂ4), 4.45 (q,1H, H-
5 of ), 4.35 (q, 1H, H-5 of ), 4.03 (d, 1H, H-2 of ), 3.77 (d, 1H, H-2
), 2.21, 2.14, 2.12, 1.99, 1.95, 1.19 (d, 2H, H-6 of ), 1.15 (d, 2H, H-6
); 13C NMR (400 MHz, CDCl3, 300 K):
170.3, 170.1, 169.9, 169.8,
d 8.59 (s, 1H, C]NH), 7.33e7.26 (m,
purified by silica gel column chromatography (toluene/
b
), 6.51 (d, 1H, H-1 of
a), 5.37e5.36 (m,
25
acetone¼60:1 to 30:1) to give 6 (1.5 g, 75%) as a colorless oil. [
a
]
D
a
a
b
), 4.79 (dd, 1H, H-3 of b
),
ꢀ19.3 (c 1.2, CHCl3); 1H NMR (400 MHz, CDCl3, 300 K):
d 7.49e6.81
(m,14H, Phꢂ3), 5.43 (s,1H, PhCH), 5.05, 4.82 (each d, 2H, PhCH2ꢂ2),
4.97 (d, 1H, H-1), 4.37 (dd,1H, H-6a), 3.91 (t,1H, H-2), 3.83e3.73 (m,
4H, H-4, PhOCH3), 3.62 (t, 1H, H-3), 3.60 (dd, 1H, 6b), 3.52 (q, 1H, H-
b
a
a
a
of
of
b
b
d
5); 13C NMR (400 MHz, CDCl3, 300 K):
d
137.9, 136.8, 129.1, 128.4,
161.0, 138.3, 137.5, 129.6, 128.4, 128.3, 128.2, 128.1, 128.0, 127.6,
127.5, 127.4, 127.3, 103.4. 94.4 (C-1 of ), 91.0 (C-1 of ), 77.2
(PhCH2O), 74.6 (C-2 of ), 72.8 (PhCH2O), 72.6 (C-2 of ), 70.9 (C-3 of
), 70.7 (C-3 of ), 69.8 (C-5 of ), 68.7 (C-5 of ), 67.3 (C-4 of ), 65.8
), 15.4 (C-6 of ); LCeMS
128.3, 128.2, 128.1, 128.0, 127.9, 126.1, 125.9, 118.6, 114.6, 102.9
(PhCH), 101.8 (C-1), 81.6 (C-2), 80.3 (C-3), 75.0 (PhCH2O), 73.3 (C-5),
68.7 (C-6þ), 66.3 (C-4), 55.7 (PhOCH3); LCeMS (ESI) calcd for
C27H29O7 (MþH)þ m/z 464.18; measured m/z 464.18.
a
b
b
a
a
b
a
b
a
(C-4 of
b
), 20.9, 20.8, 20.7, 16.0 (C-6 of
a
b
(ESI) calcd for C19H22Cl3NO7 (MþH)þ m/z 481.05; measured m/z
þ
4.4. Phenyl 3,4-di-O-acetyl-2-O-benzyl-1-thio-
b-D-fucopyr-
481.05.
anoside (10)
4.7. 4-Methoxyphenyl 2,3,4,6-tetra-O-acetyl-b-D-galactopyr-
H2O (5.0 mL) was added dropwise to a solution of 9 (3.1 g,
8.0 mmol) in AcOH (50 mL), and the reaction mixture was stirred
for 4 h at 50 ꢁC, and then concentrated with EtOH. Ac2O (30 mL)
was added to a solution of the residue in pyridine (30 mL) at 0 ꢁC,
and the reaction mixture was stirred for 16 h. The reaction was
quenched by MeOH and concentrated with toluene. The crude
product was purified by silica gel column chromatography (hex-
anosyl-(1/4)-3-O-allyl-2,6-di-O-benzyl-b-D-glucopyranoside
(14)
A solution of 5 (1.77 g, 3.5 mmol) and 13 (3.43 g, 7.0 mmol)
containing activated type AW-300 molecular sieves (5.5 g) in dry
CH2Cl2 (11 mL) was stirred under a nitrogen atmosphere for 2 h at
room temperature. After cooling to
0 mL,
ꢁC, TMSOTf (253
ane/AcOEt¼8:1 to 4:1) to give 10 (1.6 g, 90%) as a colorless oil.
1.4 mmol) was added, and the mixture was stirred for 1.5 h at 0 ꢁC.
The reaction mixture was neutralized with Et3N, filtered, and
extracted with CHCl3. The organic solvent was washed with
aqueous NaHCO3, dried, and concentrated to give clear oil. The
crude product was purified by silica gel column chromatography
25
[
d
a
]
þ5.2 (c 0.74, CHCl3); 1H NMR (400 MHz, CDCl3, 300 K):
D
7.60e7.25 (m, 5H, Ph), 5.24 (d, 1H, H-4), 5.03 (dd, 1H, H-3), 4.85,
4.58 (each d, 2H, PhCH2Oꢂ2), 4.72 (d, 1H, J1,2¼9.7 Hz, H-1), 3.78
(m, 1H, H-5), 3.72 (t, 1H, H-2), 2.14, 1.92 (each s, 6H, Acꢂ2), 1.23 (d,
3H, H-6); 13C NMR (400 MHz, CDCl3, 300 K):
d
170.2, 169.2 (CH3C]
(hexane/AcOEt¼3:1 to 3:2) to give 14 (2.1 g, 72%) as a colorless oil.
25
Oꢂ2), 137.7, 133.4, 131.8, 128.1, 127.6, 127.6, 87.6 (C-1), 75.3
(PhCH2O), 75.1 (C-2), 74.6 (C-3), 72.8 (C-5), 70.9 (C-4), 20.8, 16.6
(C-6); LCeMS (ESI) calcd for C23H27O6Sþ (MþH)þ m/z 430.15;
measured m/z 430.15.
[
d
a
]
ꢀ13.2 (c 0.63, CHCl3); 1H NMR (400 MHz, CDCl3, 300 K):
D
7.48e6.78 (m, 4H, phꢂ3), 5.98 (m, 1H, OCH2CH]CH2), 5.40 (dd,
2H, OCH2CH]CH2), 5.30 (d, 1H, H-40), 5.18 (t, 1H, H-20), 4.98, 4.88,
4.80, 4.48 (each d, 4H, PhCH2Oꢂ4), 4.95 (dd, 1H, H-30), 4.81 (d, 1H,
H-1), 4.69 (d, 1H, J1,2¼7.8 Hz, H-10), 4.13e4.10 (m, 3H, H-6a, H-6b,
OCH2CH]CH2), 3.87 (t, 1H, H-3), 3.77e3.74 (m, 5H, H-5, H-6a0,
PhOCH3), 3.71 (t, 1H, H-6b0), 3.62 (dd, 1H, OCH2CH]CH2), 3.58 (t,
1H, H-2), 3.53 (t, 1H, H-4), 3.47 (q, 1H, H-50), 2.16, 2.13, 2.06, 2.05
4.5. 3,4-Di-O-acetyl-2-O-benzyl-D-fucopyranose (11)
NBS (1.27 g, 7.7 mmol) was added to a solution of 10 (2.2 g,
5.1 mmol) in acetone (45 mL) and H2O (5.0 mL) at ꢀ10 ꢁC, and the
reaction mixture was stirred for 12 h at room temperature. The
reaction mixture was extracted with CHCl3, washed with aqueous
NaHCO3, dried, and concentrated. The crude product was purified
by silica gel column chromatography (hexane/AcOEt¼5:1) to give
(each s, 12H, Acꢂ4); 13C NMR (400 MHz, CDCl3, 300 K):
d 171.1,
170.1, 169.9, 169.8 (CH3C]Oꢂ4), 155.1, 151.2, 138.1, 137.8, 135.2,
128.3, 127.9, 127.7, 127.6, 127.5, 118.4, 115.7, 102.5 (C-1), 100.4 (C-10),
82.5 (C-4), 81.5 (C-2), 77.2 (C-3), 75.0 (C-50), 74.6 (PhCH2O), 73.6
(PhCH2O), 71.1 (C-5), 70.5 (C-30), 69.7 (C-60), 68.1 (C-20), 67.9
(OCH2CH]CH2), 66.9 (C-40), 61.0 (C-6), 55.7 (PhOCH3), 20.8
the
Mp 100e103 ꢁC; [
CDCl3, 300 K):
of
4.70, 4.69, 4.66 (each d, 4H, PhCH2ꢂ4), 4.73 (d, 1H, J1,2¼7.8 Hz, H-1
of ), 4.37 (q, 1H, H-5 of ), 3.83 (t, 1H, H-2 of ), 3.87 (q, 1H, H-5 of
), 3.58 (t, 1H, H-2 of ), 2.14, 2.13, 1.99, 1.96, 1.19 (d, 3H, H-6 of ),
1.10 (d, 3H, H-6 of 170.3,
); 13C NMR (400 MHz, CDCl3, 300 K):
170.2, 169.8, 137.6, 128.3, 128.1, 127.8, 127.6, 127.5, 127.4, 97.3 (C-1 of
), 91.5 (C-1 of ), 77.5 (PhCH2O), 74.7 (PhCH2O), 73.8 (C-2 of ), 73.2
(C-3 of ), 72.7(C-3 of ), 71.4 (C-5 of ), 70.7(C-2 of ), 69.7 (C-5 of
a
and
b
isomers of 11 (1.6 g, 90%,
a
/
b
¼0.99:1.0) as a white solid.
25
þ
a
]
D
ꢀ17.2 (c 0.31, CHCl3); 1H NMR (400 MHz,
(CH3C]Oꢂ4); LCeMS (ESI) calcd for C44H53O16 (MþH)þ m/z
d
7.36e7.22, 5.33e5.26 (m, 3H, H-3 of
a, H-4 of
a
, H-4
836.33; measured m/z 836.33.
b
), 5.20 (d, 1H, J1,2¼2.3 Hz, H-1 of
a), 4.98 (dd, 1H, H-3 of b), 4.90,
4.8. 4-Methoxyphenyl 2,3,4,6-tetra-O-acetyl-b-D-galactopyr-
b
a
a
anosyl-(1/4)-2,6-di-O-benzyl- -glucopyranoside (15)
b-D
b
b
b
a
d
AcONa (12 g) and PdCl2 (5.4 g) were added to a solution of 14
(2.1 g, 2.5 mmol) in AcOH (100 mL) and H2O (10 mL), and the reaction
mixture was stirred for 12 h at room temperature. The reaction
mixture was filtered, extracted with AcOEt, washed with aqueous
a
b
b
b
a
b
a

1474
I. Ohtsuka et al. / Tetrahedron 69 (2013) 1470e1475
NaHCO3, dried, and concentrated. The crude product was purified by
4.11. 4-Methoxyphenyl 2,3,4,6-tetra-O-benzoyl-
actopyranosyl-(1/4)-[2,3,4-tri-O-benzoyl- -fucopyranosyl-
(1/3)]-2,6-di-O-benzoyl- -glucopyranoside (17)
b-D-gal-
silica gel column chromatography (toluene/acetone¼60:1 to 30:1) to
a-D
25
give 15 (1.5 g, 75%) as a colorless oil. [
a
]
ꢀ10.7 (c 1.0, CHCl3); 1H
b-D
D
NMR (400 MHz, CDCl3, 300 K):
d
7.41e6.78 (m, 14H, Phꢂ3), 5.45 (d,
1H, H-40), 5.19 (t,1H, H-20), 4.97 (dd,1H, H-30), 4.83 (d,1H, J1,2¼7.3 Hz,
H-1), 4.92, 4.86, 4.69, 4.48 (each d, 4H, PhCH2Oꢂ4), 4.52 (d, 1H,
J1,2¼7.7 Hz, H-10), 4.15e4.13 (m, 2H, H-6a, H-6b), 3.94 (br t, 1H, H-3),
3.81 (t, 1H, H-4), 3.77e3.62 (H-5, H-6a0, H-6b0, PhOCH3), 3.56 (t, 1H,
H-2), 3.54 (q, 1H, H-50), 2.16, 2.13, 2.06, 2.05 (each s, 12H, Acꢂ4); 13C
Pd/C (10%, 500 mg) was added to a solution of 16 (503 mg,
0.45 mmol) in MeOH (3.0 mL) and AcOH (3.0 mL), and the reaction
mixture was stirred under hydrogen atmosphere for 12 h at room
temperature. The mixture was filtered, concentrated, and redis-
solved in MeOH (10 mL). To the solution, 30% NaOMe (100 mL) in
MeOH was added, and the mixture was stirred for 2 h at room
temperature. The residue was protected with benzoyl chloride
NMR (400 MHz, CDCl3, 300 K):
d
170.1, 169.9, 169.8, 169.7 (CH3C]
Oꢂ4), 138.8, 137.8, 128.3, 128.1, 127.4, 127.4, 102.1 (C-1), 101.4 (C-10),
80.7 (C-2), 75.1 (C-4), 74.8 (C-3), 73.9 (PhCH2O), 73.6 (C-50), 71.7 (C-
30), 70.8 (PhCH2O), 68.9 (C-60), 68.0 (C-20), 67.5 (C-40), 61.6 (C-6), 55.þ7
(PhOCH3), , 20.8 (CH3C]Oꢂ4); LCeMS (ESI) calcd for C41H49O16
(MþH)þ m/z 796.29; measured m/z 796.29.
(313 mL, 2.7 mmol) in pyridine (10 mL) for 3 h. The reaction mixture
was quenched with MeOH at 0 ꢁC and extracted with CHCl3. The
extract was washed with 5% HCl and aqueous NaHCO3, dried, and
concentrated. The crude product was purified by silica gel column
chromatography (toluene/acetone¼40:1 to 15:1) to give 17 (400 mg,
25
58%dthree steps) as a colorless oil. [
a
]
ꢀ70.2 (c 1.0, CHCl3); 1H
D
4.9. 4-Methoxyphenyl 2,3,4,6-tetra-O-acetyl-
anosyl-(1/4)-[3,4-di-O-acetyl-2-O-benzyl-
(1/3)]-2,6-di-O-benzyl- -glucopyranoside (16)
b-D-galactopyr-
NMR (400 MHz, CDCl3, 300 K):
d
8.13e6.62 (m, 45H, Phꢂ10), 5.94
b-D-fucopyranosyl-
(dd, 1H, H-300), 5.84e5.74 (m, 4H, H-2, H-20, H-40, H-100), 5.67 (d, 1H,
H-400), 5.53 (dd,1H, H-30), 5.23 (d,1H, H-1), 4.86 (d,1H, H-10), 4.76 (q,
1H, H-500), 4.58 (dd, 1H, H-6a), 4.52 (dd, 1H, H-6a0), 4.49 (t, 1H, H-3),
4.45e4.37 (m, 2H, H-6b, H-5), 4.28 (t, 1H, H-6b0), 4.05 (q, 1H, H-50),
3.99 (t, 1H, H-4), 3.70 (s, 3H, PhCH3), 1.59 (d, 3H, H-600); 13C NMR
b-D
A solution of 15 (900 mg, 1.1 mmol) and 10 (995 mg, 2.2 mmol)
containing activated type AW-300 molecular sieves (3.0 g) in dry
CH2Cl2 (6.0 mL) was stirred under a nitrogen atmosphere for 2 h at
room temperature. After cooling to 0 ꢁC, NIS (1.0 g 4.4 mmol) and
(400 MHz, CDCl3, 300 K):
d 165.7, 165.6, 165.5, 165.2, 165.1, 164.9,
164.8,164.8,155.1,100.9 (C-10), 99.2 (C-1), 96.9 (C-100), 77.2, 76.5, 75.7,
73.5, 71.9, 71.8, 69.8, 69.1, 68.8,þ67.8, 66.0, 63.5, 61.8, 55.6, 16.1;
LCeMS (ESI) calcd for C88H75O25 (MþH)þ m/z 1530.45; measured
m/z 1530.45.
TfOH (42 mL, 0.44 mmol) were added sequentially, and the mixture
was stirred for 1.5 h at 0 ꢁC. The reaction mixture was neutralized
with Et3N, filtered, and extracted with CHCl3. The organic solvent
was washed with aqueous sodium thiosulfate, dried, and con-
centrated to give a clear oil. The crude product was purified by
silica gel column chromatography (toluene/acetone¼40:1 to 15:1)
4.12. 2,3,4,6-Tetra-O-benzoyl-
[2,3,4-tri-O-benzoyl- -fucopyranosyl-(1/3)]-2,6-di-O-ben-
zoyl- -glucopyranose (18)
b-D-galactopyranosyl-(1/4)-
25
to give 16 (900 mg, 72%) as a colorless oil. [
a
]
ꢀ20.2 (c 0.8,
a-D
D
CHCl3); 1H NMR (400 MHz, CDCl3, 300 K):
d
7.51e6.72 (m, 21H,
b-D
Phꢂ4), 5.76 (br s, 1H, H-100), 5.38 (dd, 1H, H-300), 5.19 (d, 1H, H-400),
5.14 (t, 1H, H-20), 5.10 (dd, 1H, H-30), 5.01 (d, 1H, J1,2¼7.4 Hz, H-1),
4.89 (d, 1H, H-40), 4.81e4.51 (m, 6H, PhCH2Oꢂ6), 4.71 (d, 1H,
J1,2¼7.8 Hz, H-10), 4.39 (q, 1H, H-500), 4.29 (t, 1H, H-6a), 4.09e4.02
(m, H-6a0, H-6b), 3.88e3.78 (m, 6H, H-2, H-6b0, H-200, PhOCH3),
3.60 (q, 1H, H-5), 3.43 (q, 1H, H-50), 1.70 (d, 3H, H-600), 2.11, 2.02,
1.96, 1.95, 1.94, 1.88 (Acꢂ6); 13C NMR (400 MHz, CDCl3, 300 K):
CAN (722 mg, 1.3 mmol) was added to a solution of 17
(400 mg, 0.26 mmol) in CH3CN (6.0 mL) and H2O (1.0 mL), and the
reaction mixture was stirred for 2 h at room temperature. The
reaction mixture was extracted with AcOEt, washed with aqueous
NaHCO3, dried, and concentrated. The crude product was purified
by silica gel column chromatography (toluene/acetone¼40:1 to
25
d
170.2, 169.9, 169.8, 169.7, 168.8, 155.1, 151.0, 137.9, 137.5, 128.3,
10:1) to give 18 (260 mg, 77%) as a yellow oil. [
a
]
ꢀ23.0 (c 1.0,
D
128.2, 128.1, 128.0, 127.9, 127.8, 127.7, 127.6, 118.1, 118.0, 102.7 (C-1),
98.8 (C-10), 95.9 (C-100), 80.1, 77.2, 75.5, 75.2, 75.1, 73.6, 72.6, 72.0,
71.9, 71.7, 71.0, 70.9, 69.4, 69.3, 69.1, 68þ.7, 66.8, 64.2, 60.8, 55.7,
15.4; LCeMS (ESI) calcd for C58H69O22 (MþH)þ m/z 1116.42;
measured m/z 1116.42.
CHCl3); 1H NMR (400 MHz, CDCl3, 300 K):
d
5.58 (d, 1H,
J1,2¼2.9 Hz, H-100), 5.00 (d, 1H, J1,2¼7.8 Hz, H-10), 4.64 (d, 1H,
J1,2¼7.3 Hz, H-1); 13C NMR (400 MHz, CDCl3, 300 K):
d 165.9, 165.7,
165.6, 165.5, 165.4, 165.3, 165.1, 164.8, 133.3, 133.2, 133.1, 132.5,
129.9, 129.8, 129.6, 129.5, 129.4, 129.3, 129.1, 129.0, 128.7, 128.6,
128.5, 128.4, 128.3, 128.1, 127.8, 101.3 (C-10), 96.2 (C-100), 89.9 (C-1),
77.2, 74.4, 72.1, 71.9, 71.9, 70.1, 69.0, 68þ.9, 67.8, 68.8, 61.8, 29.8,
15.9; LCeMS (ESI) calcd for C81H59O24 (MþH)þ m/z 1424.21;
measured m/z 1424.41.
4.10. Synthetic procedure of 16 using the one-pot glycosyla-
tion strategy
A solution of 6 (164 mg, 0.35 mmol) and 12 (255 mg, 0.5 mmol) in
dry CH2Cl2 (3.0 mL) was stirred under a nitrogen atmosphere for 2 h
4.13. 2,3,4,6-Tetra-O-benzoyl-
[2,3,4-tri-O-benzoyl- -fucopyranosyl-(1/3)]-2,6-di-O-ben-
zoyl- -glucopyranosyltrichloroacetoimidate (19)
b-D-galactopyranosyl-(1/4)-
at room temperature. After cooling to 0 ꢁC, TfOH (3.2
mL, 35
mmol)
a-D
was added, and the mixture was stirred at 0 ꢁC for 30 min. The re-
D
action mixture was then cooled to ꢀ78 ꢁC, and TfOH (49
mL,
0.5 mmol) and triethylsilane (112
m
L, 0.7 mmol) were added se-
Cl3CCN (183 mL, 1.8 mmol) and DBU (36 mL, 0.27 mmol) were
quentially. The reaction mixture was stirred again for 1 h at ꢀ78 ꢁC.
For the second glycosylation, 13 (312 mg, 0.64 mmol) dissolved in
dry CH2Cl2 (1.0 mL) was added, and the mixture was allowed to
warm to 0 ꢁC while stirring for 3 h. The reaction mixture was
quenched by Et3N, filtered, and extracted with CHCl3. The organic
solvent was washed with aqueous NaHCO3, dried, and concentrated
to give a clear oil. The crude product was purified by silica gel column
chromatography (toluene/acetone¼40:1 to 15:1) to give 16 (165 mg,
47% over three steps).
added to a solution of 18 (260 mg, 0.18 mmol) in CH2Cl2 (3.0 mL) at
0 ꢁC, and the reaction mixture was stirred for 1 h. After completion of
the reaction, the mixture was concentrated. Column chromatogra-
phy of the residue on silica gel (toluene/acetone¼100:1, then 10:1)
gave 19 (234 mg, 81%) as a colorless oil. [
a
]
25 þ88.6 (c 2.0, CHCl3); 1H
D
NMR (400 MHz, CDCl3, 300 K):
d
8.55, 8.54 (each s, 2H, NHCCl3ꢂ2),
6.70 (d, 1H, J1,2¼3.2 Hz, H-1 of
a
), 6.58 (d, 1H, J1,2¼7.0 Hz, H-1 of
b);
þ
LCeMS (ESI) calcd for C83H69Cl3NO24 (MþH)þ m/z 1567.32; mea-
sured m/z 1567.32.

I. Ohtsuka et al. / Tetrahedron 69 (2013) 1470e1475
1475
4.14. 2,3,4,6-Tetra-O-benzoyl-
[2,3,4-tri-O-benzoyl- -fucopyranosyl-(1/3)]-2,6-di-O-ben-
zoyl- -glucopyranosyl-(1/3)-(1/1)-(2S,3S,4R)-3,4-di-O-
b
-
D
-galactopyranosyl-(1/4)-
300 K):
d
4.99 (d, 1H, J1,2¼3.5 Hz, H-100), 4.43 (d, 1H, J1,2¼7.3 Hz, H-1),
a-D
4.35 (d,1H, J1,2¼7.8 Hz, H-10); 13C NMR (400 MHz, CD3OD:CDCl3¼1:1,
b-D
300 K): d
174.9,103.9 (C-10), 103.3 (C-1), 102.5 (C-100), 77.8, 76.2, 75.4,
benzyl-2-hexadecanamido-octadecane-3,4-di-ol (21)
74.6, 74.0, 73.9, 72.8, 72.6, 71.8, 71.0, 70.8, 70.3, 69.7, 69.5, 68.7, 62.6,
60.3, 37.0, 32.6, 26.6, 14.4; HRMS (FAB) calcd for C52H99NO18Naþ
(MþNa)þ m/z 1048.6760; measured m/z 1048.6722.
A solution of 19 (234 mg, 0.15 mmol) and (2S,3S,4R)-3,4-di-O-
benzyl-2-hexadecanamido-octadecane-3,4-diol 20 (220 mg,
0.29 mmol) containing activated type AW-300 molecular sieves
(2.0 g) in dry CH2Cl2 (4.0 mL) was stirred under nitrogen atmosphere
Acknowledgements
for 2 h at room temperature. After cooling to 0 ꢁC, TMSOTf (22
mL,
This study was supported by a Grant-in-Aid for Scientific Re-
search from the Ministry of Education, Culture, Sports, Science and
Technology of Japan, and by the Otsuka Pharmaceutical Award in
Synthetic Organic Chemistry Japan Fund. The authors are grateful
to Ms. J. Hada for providing HRMS data.
1.2 mmol) was added, and the solution was stirred for 1.5 h at 0 ꢁC.
The mixture was neutralized with Et3N, filtered, and extracted with
CHCl3. The organic solvent was washed with aqueous NaHCO3, dried,
and concentrated to give a clear oil. The crude product was purified
by silica gel column chromatography (hexane/AcOEt¼4:1 to 2.5:1) to
give 21 (130 mg, 41%) as a colorless oil. [
a
]
25 ꢀ20.3 (c 1.0, CHCl3); 1H
D
NMR (400 MHz, CDCl3, 300 K):
d
8.11e6.99 (m, 77H, Phꢂ11), 5.85 (d,
Supplementary data
1H, J1,2¼2.9 Hz, H-100), 5.81 (t, 1H, H-20), 5.76 (dd, 1H, H-300), 5.57 (d,
1H, H-40), 5.45 (t, 1H, H-200), 5.44 (dd, 1H, H-30), 5.32 (d, 1H, H-400),
4.94 (d, 1H, J1,2¼8.1 Hz, H-10), 4.79 (d, 1H, PhCH2O), 4.62e4.43 (m,
11H, PhCH2Oꢂ3, H-1, H-2, H-3, H-6a, H-6b, H-6a0, H-6b0, H-500), 4.33
(t,1H, H-4), 4.19 (dd,1H, OCH2), 4.01 (q,1H, H-50), 3.95 (t,1H, CHOH),
3.81 (m, 2H, H-5, OCH2CHN), 3.33 (d, 1H, CHOH), 3.14 (dd,1H, OCH2),
Supplementary data associated with this article can be found in
the online version, at http://dx.doi.org/10.1016/j.tet.2012.12.023.
These data include MOL files and InChiKeys of the most important
compounds described in this article.
1.59 (d, 3H, H-600); 13C NMR (400 MHz, CDCl3, 300 K): 101.1 (C-10),
d
100.1 (C-1), 96.1 (C-100), 79.7, 77.1, 74.1, 73.3, 71.8, 71.7, 71.2, 69.8, 68.8,
67.6, 65.8, 62.þ9, 61.5, 36.1, 31.9, 22.6, 14.1; LCeMS (ESI) calcd for
C129H148NO27 (MþH)þ m/z 2142.02; measured m/z 2142.02.
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Takahashi, T. Org. Lett. 2002, 4, 4213e4216.
17. Mong, K.-K. T.; Wong, C.-H. Angew. Chem., Int. Ed. 2002, 41, 4087e4090.
18. Vohra, Y.; Vasan, M.; Venot, A.; Boons, G.-J. Org. Lett. 2008, 10, 3247e3250.
19. Jiansong, S.; Xiuwen, H.; Biao, Y. Synlett 2005, 437e440.
20. (a) Olvoot, J. J.; Boeckel, C. A. A. V.; Koning, J. H. D.; Van Boom, J. H. Synthesis
1981, 305e308; (b) Ogawa, T.; Nakabayashi, S.; Kitajima, T. Carbohydr. Res.
1983, 114, 225e236; (c) Liu, X.; Stocker, B. L.; Seeberger, P. H. J. Am. Chem. Soc.
2006, 128, 3638e3648.
Pd/C (10%, 60 mg) was added to a solution of 21 (56 mg, 26 mmol)
in CH2Cl2 (2.0 mL), MeOH (2.0 mL), and AcOH (2.0 mL), and the re-
action mixture was stirred under hydrogen atmosphere for 12 h at
room temperature. The solution was then filtered and concentrated.
The crude product was purified by silica gel column chromatography
(hexane/AcOEt¼3:1 to 1:1) to give 22 (46 mg, 90%) as a white solid.
Mp 123e126 ꢁC; [
a
]
25 ꢀ15.2 (c 1.1, CHCl3); 1H NMR (400 MHz, CDCl3,
D
300 K):
d
8.08e7.04 (m, 45H, Phꢂ9), 6.08 (d, 1H, H-40), 5.91 (d, 1H,
J1,2¼3.2 Hz, H-100), 5.88e5.76 (m, 3H, H-20, H-200, H-300), 5.51 (dd, 1H,
H-30), 5.34 (d,1H, H-400), 4.97 (d,1H, J1,2¼8.0 Hz, H-10), 4.61 (m,1H, H-
500), 4.52 (d, 1H, J1,2¼7.0 Hz, H-1), 4.61e4.46 (m, 4H, H-6a, H-6b, H-
6a0, H-6b0), 4.39 (t,1H, H-3), 4.20 (t,1H, H-4), 4.16 (dd,1H, OCH2), 4.09
(q, 1H, H-50), 3.88 (q, 1H, H-5), 3.53 (m, 2H, OCH2CHN, CHOH), 3.43
(dd, 1H, OCH2), 3.25 (d, 1H, CHOH), 1.59 (d, 3H, H-600); 13C NMR
(400 MHz, CDCl3, 300 K):
d 172.9, 165.8, 165.6, 165.5, 165.4, 165.2,
165.1, 165.0, 164.6, 101.1 (C-10), 100.7 (C-1), 96.3 (C-100), 77.2, 75.6,
74.5, 73.7, 72.9, 72.8, 72.0, 71.8, 69.9, 69.7, 68.9, 68.7, 67.7, 66.0, 62.9,
21. Kiyoi, T.; Nakai, Y.; Kondo, H.; Ishida, H.; Kiso, M.; Hasegawa, A. Bioorg. Med.
Chem. 1996, 4, 1167e1176.
þ
61.7, 36.5, 32.9, 25.9, 14.3; LCeMS (ESI) calcd for C115H135NO27
22. (a) Lin, C.-C.; Huang, K. T.; Lin, C.-C. Org. Lett. 2005, 7, 4169e4172; (b) Martin, T. J.;
Schmidt, R. R. Tetrahedron Lett. 1992, 33, 6123e6126; (c) Tanaka, H.; Nishida, Y.;
Adachi, M.; Takahashi, T. Heterocycles 2006, 67, 107e112; (d) Kondo, H.; Ichi-
kawa, Y.; Wong, C.-H. J. Am. Chem. Soc. 1992, 114, 8748e8750.
23. Pozsgay, V.; Kubler-Kielb, J.; Coxon, B.; Marques, A.; Robbins, J. B.; Schneerson,
R. Carbohydr. Res. 2011, 346, 1551e1563.
24. Schmidt, R. R. Angew. Chem., Int. Ed. Engl. 1986, 25, 213e236.
25. Matsuoka, K.; Terabatake, M.; Umino, A.; Esumi, Y.; Hatano, K.; Terunuma, D.;
Kazuhara, H. Biomolecules 2006, 7, 2274e2283.
(MþH)þ m/z 1961.92; measured m/z 1961.92.
4.16.
(1/3)]-
hexadecanamido-octadecane-3,4-di-ol (2)
b-D-Galactopyranosyl-(1/4)-[b-a-fucopyranosyl-
b-D-glucopyranosyl-(1/3)-(1/1)-(2S,3S,4R)-2-
26. Veeneman, G. H.; van Boom, J. H. Tetrahedron Lett. 1990, 31, 1331e1334.
27. (a) Fugedi, P. J. Carbohydr. Chem. 1987, 6, 377e398; (b) Fugedi, P.; Nanasi, P.;
NaOMe (30%) in MeOH (50
mL) was added to a solution of 22
€
€
ꢀ ꢀ
(46 mg, 23 mol) in MeOH (4.0 mL) and 1,4-dioxane (4.0 mL) at
m
Szejtli, J. Carbohydr. Res. 1988, 175, 173e181.
40 ꢁC, and the mixture was stirred for 8 h. The reaction mixture was
neutralized with Amberlite IR-120 (Hþ form), filtered, and concen-
trated. The product was purified by Sephadex LH-20 column chro-
matography (100% MeOH) to give 16 (12 mg, 50%) as a white solid.
28. (a) Wang, C. C.; Lee, J. C.; Luo, S.; Fan, H. F.; Pai, C. L.; Yang, W. C.; Lu, L. D.;
Huang, S. H. Angew. Chem., Int. Ed. 2002, 41, 2360e2362; (b) Sakagami, M.;
Hanashima, H. Tetrahedron Lett. 2000, 41, 5547e5551.
29. Hanashima, S.; Seeberger, P. H. Chem. Asian J. 2007, 2, 1447e1459.
30. Kanaya, T.; Yagi, S.; Schweizer, F.; Takeda, T.; Kiuchi, F.; Hada, N. Chem. Pharm.
Bull. 2010, 58, 811e817.
Mp 99e101 ꢁC; [
a]
D
25 ꢀ16.0 (c 0.3, MeOH); 1H NMR (400 MHz, CDCl3,