Synthesis and antibacterial evaluation of a series of oligorhamnoside derivatives

Article abstract of DOI:10.1016/j.carres.2011.07.028

A series of novel oligorhamnoside derivatives (1-10) and naturally occurring cleistrioside-5 were synthesized and evaluated for their in vitro antibacterial activities. Among them, dirhamnoside derivative 7 and cleistrioside-5 displayed similar antibacter

Full text of DOI:10.1016/j.carres.2011.07.028

Carbohydrate Research 346 (2011) 2126–2135
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Carbohydrate Research
journal homepage: www.elsevier.com/locate/carres
Synthesis and antibacterial evaluation of a series of oligorhamnoside derivatives
Ning Ding a, Zaihong Zhang b, Wei Zhang a, Yuexing Chun b, Peng Wang b, Huimin Qi c, Shan Wang c,
Yingxia Li a,
⇑
a Department of Medicinal Chemistry, School of Pharmacy, Fudan University, Shanghai 201203, China
b School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China
c Institute of Clinical Pharmacology, The First Hospital, Peking University, China
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 18 May 2011
Received in revised form 29 July 2011
Accepted 31 July 2011
Available online 9 August 2011
A series of novel oligorhamnoside derivatives (1–10) and naturally occurring cleistrioside-5 were synthe-
sized and evaluated for their in vitro antibacterial activities. Among them, dirhamnoside derivative 7 and
cleistrioside-5 displayed similar antibacterial profiles and exhibited moderate to good inhibitory activi-
ties on bacterial growth against a panel of Gram-positive bacteria (MICs ꢀ 4–32
lg/mL). The results
revealed that these two compounds showed selectivity towards bacterial species strictly, without being
affected by the antibiotic-resistant/susceptible properties of one species, which suggested that they
might have the potential to avoid antibiotic cross-resistance. In addition, the preliminary SARs of this
type of oligorhamnoside derivatives on the antibacterial activities were determined.
Ó 2011 Elsevier Ltd. All rights reserved.
Keywords:
Oligorhamnoside
Antibacterial activities
Cleistrioside
Cleistetrosides
Antibiotic-resistant
1. Introduction
Two series of partially acetylated dodecanyl tetra- and tri-
rhamnoside derivatives cleistetrosides-1–8, and cleistriosides-1–6
The rising incidence of infections caused by antibiotic-resistant
microorganisms has become a major concern for clinicians and the
public health system. However, despite a push for new antibiotic
therapies there has been a continued decline in the number of
newly approved drugs.1 In this respect, new prototype antibacte-
rial agents with unique chemical structures, dissimilar toxicities,
broad spectrum of activities and cross-resistances with present
drug therapies are desperately needed.
Oligosaccharides play an important role in biological systems,
such as cell–cell interaction, cell adhesion, and immunogenic recog-
nition.2 Most of them are primary ingredients of the cell-wall poly-
saccharides of bacteria.3 The polysaccharides of pathogenic bacteria
are responsible for the immunogenic activities4 and contribute to
bacterial virulence.5 Oligosaccharides that share similar chemical
structure with primary ingredients of bacterial polysaccharides
may disrupt the biosynthesis of bacterial polysaccharides and de-
stroy their virulence.4 Rhamnose-containing oligosaccharides are
widely distributed in natural products, such as triterpenoid glyco-
sides,6 K-antigens,7 and a series of glycolipids from mycobacteria.8,9
Because rhamnose-containing oligosaccharides are not present in
mammalian cells,10 they may have the potential to overcome the
lack of specificity and resistance encountered with currently used
antibiotics.
were previously isolated11 from Cleistopholis spp. (Fig. 1). Among
them several compounds have been shown to have significant
in vitro antibacterial activities. For example, cleistetroside-2, cle-
istetroside-8 and cleistriosides-5 were found to possess significant
antibacterial activities against the Gram-positive methicillin-resis-
tant S. aureus ATCC 33591 and S. aureus 78-13607A with MICs of
ꢀ16
l
g/mL.11a Furthermore, cleistriosides-5 and cleistetroside-2
displayed significant antibacterial activities against an expanded
panel of Gram-positive pathogens including either ATCC strains
or well-characterized clinical isolates from the global SENTRY Anti-
microbial Surveillance Program.11a
The ability of partially acetylated simple rhamnoside deriva-
tives to have significant in vitro inhibition on bacterial growth is
interesting. Whereas, not all compounds in these two series have
antibacterial activities as efficient as those above mentioned. Be-
cause each series of compounds shares a same oligorhamnoside
skeleton, the observed variety of antibacterial activities indicated
that the acetyl groups might play an important role on the under-
lying mechanism of action. In addition, the sugar chain length of
three and four seemed to have no influence on the antibacterial
activities because both cleistriosides-5 and cleistetroside-2 had
the best antibacterial profiles against the panel of bacteria. To elu-
cidate the contribution of the acetyl groups on antibacterial activ-
ities, and also to further understand the correlation between the
sugar chain length and inhibitory activities, structure–activity rela-
tionships (SARs) of these compounds are a particularly attractive
⇑
Corresponding author. Tel./fax: +86 21 51980127.
E-mail address: liyx417@fudan.edu.cn (Y. Li).
0008-6215/$ - see front matter Ó 2011 Elsevier Ltd. All rights reserved.
doi:10.1016/j.carres.2011.07.028

N. Ding et al. / Carbohydrate Research 346 (2011) 2126–2135
2127
OC12H25
O
OC12H25
O
O
O
HO
OH
HO
O
OH
O
AcO
AcO
O
OH
O
OH
O
R1O
O
Cleistetroside-1: R1=R3=R4=Ac, R2=H
Cleistetroside-2: R1=R4=Ac, R2=R3=H
Cleistetroside-4: R1=Ac, R2=R3=R4=H
Cleistetroside-5: R1=R2=R3=R4=H
Cleistetroside-6: R1=R2=R4=Ac, R3=H
Cleistetroside-8: R1=R3=Ac, R2=R4=H
R2O
R1O
O
OAc
OAc
O
R4O
R3O
Cleistrioside-5: R1=H, R2=Ac
Cleistrioside-6: R1=Ac, R2=H
OR2
Figure 1. Eight partially acetylated oligorhamnosides from Cleistopholis patens.
direction. With our continuous interest in the biological activities
of glycolipids12 and to search for potential new antimicrobial
agents, we decided to investigate the synthesis and in vitro biolog-
ical evaluation of antibacterial activities of a series of dodecanyl
oligorhamnoside derivatives. The results obtained render new
clues on understanding of the antimicrobial profile for these types
of compounds.
Cleistrioside-5 was constructed via a ‘2+1’ convergent strategy
by glycosylation of 11 with thioglycoside 12. The glycosylation
was carried out smoothly in the presence of NIS–AgOTf to provide
trisaccharide 13 in an 81% yield with exclusive
age. The
a
-glycosidic link-
a
-configuration of the newly formed glycosidic bond in
13 was confirmed by HMBC spectrum (1JC-1 ,H-1 = 170.7 Hz).
Deprotection of the Lev group in 13 with hydrazine acetate
(81%), followed by removal of the isopropylidene group (70%) led
to cleistrioside-5. Acetylation of cleistrioside-5 with Ac2O–Et3N
provided its peracetate 6 (90%).
00
00
2. Results and discussion
Monosaccharide building blocks 1813a–20 were prepared by
treating of 21 with corresponding acyl chlorides, respectively. With
glycosyl acceptor 11 and donors 18–20 in hand, glycosylations
were performed to provide three trisaccharides 22–24. Removal
of the Lev and isopropylidene protecting groups eventually gave
desired compounds 3, 4, 5, respectively.
Ten dodecanyl rhamnoside derivatives 1–10 with sugar chain
length of 1–4 and none/partially/per acylated hydroxyls were de-
signed and synthesized (Fig. 2). The natural product cleistrioside-
5, which was reported to have significant in vitro antibacterial
activities,11a was also synthesized for comparison during the anti-
bacterial activity testing.
Target disaccharide 7 was obtained by condensation of acceptor
2513a with glycosyl donor 18 (74%), followed by cleavage of the iso-
propylidene group in compound 26 with 80% HOAc (81%).
Target disaccharide 8 was prepared from key intermediate 11
in three steps. Protection of 30-OH in 11 with acetyl group
followed by removal of the Lev group led to compound 27 (83%
for two steps). Removal of the isopropylidene group (79%)
afforded compound 8.
2.1. Chemistry
The total synthesis of cleistetroside-2 has been reported by us
and others previously.13 Following a similar strategy13a as that
developed by us, the synthesis of cleistrioside-5 and target com-
pounds 1–10 were accomplished. As outlined in Scheme 1, most
of the designed compounds as well as cleistrioside-5 were synthe-
sized from coupling of the key disaccharide building block 1113a
with appropriate glycosyl donors.
Compounds 9 and 10 are known compounds and were synthe-
sized according to our previously published procedures.13a
OC12H25
OC12H25
OC12H25
O
O
O
O
O
O
HO
AcO
OH
OAc
HO
O
O
OH
AcO
AcO
O
AcO
O
O
OH
OAc
O
OH
O
O
AcO
AcO
O
RO
O
O
OH
OAc
HO
OH
O
O
3 R = Ac
4 R = Bz
AcO
AcO
AcO
HO
OH
OAc
2
5 R = Hex
1
OC12H25
OC12H25
OC12H25
O
O
O
O
O
HO
HO
AcO
OH
HO
HO
O
OAc
OH
AcO
O
AcO
RO
9
OH
O
OAc
STol
O
AcO
AcO
O
AcO
OAc
6
7
8
R = H
R = Ac
OAc
10
Figure 2. Designed compounds 1–10.

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N. Ding et al. / Carbohydrate Research 346 (2011) 2126–2135
OC12H25
O
O
O
STol
d
O
O
e
f
AcO
1
2
Me
OLev
O
Me
AcO
O
STol
HO
OLev
NH
CCl3
O
O
AcO
AcO
16
g
O
6
O
OLev
OLev
O
O
c
AcO
O
AcO
O
O
Me
O
O
O
Me
AcO
5
cleistrioside-
b
Me
Me 14
O
Me
15
O
Me
17
STol
OC12H25
OC12H25
O
O
O
AcO
LevO
OC12H25
m
O
O
O
O
OAc
O
O
Me
O
AcO
Me
O
O
Me
n
12
O
AcO
O
Me
O
O
O
8
OLev
AcO
a
Me
HO
O
OLev
O
AcO
Me
AcO
OH
11
LevO
27
13
OAc
STol
STol
RO
OC12H25
O
Me
h
O
O
O
HO
O
Me
O
O
Me
21
O
O
O
18
19
20
AcO
R=Ac
R=Bz
Me
Me
j
i
O
Me
OLev
R=Hex
3, 4, 5
O
RO
O
O
22 R=Ac
23 R=Bz
Me
Me
24
R=Hex
OC12H25
OC12H25
STol
O
O
O
O
O
O
HO
k
O
AcO
l
AcO
Me
+
Me
7
O
O
Me
O
O
O
Me
O
Me
Me
Me
25
Me
18
26
Scheme 1. Synthesis of cleistrioside-5 and target compounds 1–10. Reagents and conditions: (a) 12, NIS, AgOTf, CH2Cl2, 81%; (b) (i) NH2NH2ꢁHOAc, CH2Cl2–MeOH, 81%; (ii)
80% HOAc, 70%; (c) DMAP, Ac2O, Et3N, CH2Cl2, 90%; (d) 15, NIS, AgOTf, CH2Cl2, 65%; (e) (i) NH2NH2ꢁHOAc, CH2Cl2–MeOH, 58%; (ii) 80% HOAc, 70%; (f) DMAP, Ac2O, Et3N,
CH2Cl2, 99%; (g) TMSOTf, CH2Cl2, 77%; (h) BzCl, pyridine, 88% for 19; n-hexanoyl chloride, pyridine, 68% for 20; (i) 18, 19, or 20, NIS, AgOTf, CH2Cl2, 99% for 22, 55% for 23, 49%
for 24; (j) (i) NH2NH2ꢁHOAc, CH2Cl2–MeOH, 72% from 25, 87% from 26, 90% from 27; (ii) 80% HOAc, 81% for 3, 83% for 4, 63% for 5; (k) NIS, AgOTf, CH2Cl2, 74%; (l) 80% HOAc,
81%; (m) (i) Ac2O, Et3N, DMAP, CH2Cl2; (ii) NH2NH2ꢁHOAc, CH2Cl2–MeOH, 83% for two steps; (n) 80% HOAc, 79%.
2.2. Antibacterial activities
streptococci with MICs of ꢀ4
strains of E. faecium with MICs of ꢀ8
strains of S. epidermidis and six strains of S. aureus, the MICs were
g/mL respectively.
More interestingly, the antibacterial activities of cleistrioside-5
and compound 7 did not vary with the antibiotic-resistant/suscep-
tible properties of a certain species. For example, they were effec-
tive in inhibiting the growth of both methicillin-resistant and
susceptible S. aureus as well as S. epidermidis with MICs of
l
g/mL and good activities against five
l
g/mL. As for the tested six
Target compounds 1–10 and cleistrioside-5 were evaluated for
their in vitro antibacterial activities against a panel of bacteria
including both antibiotic resistant and susceptible strains follow-
ing a standard testing method.14 The minimum inhibitory concen-
tration (MIC) is defined as the concentration of the compound
required to give 80% inhibition of bacteria growth. Selected MICs
of the target compounds and cleistrioside-5 along with those of
Vancomycin and Oxacillin are presented in Table 1.
As expected, all the tested compounds showed no antibacterial
activities against Gram-negative bacteria E. coli., whereas the syn-
thetic cleistrioside-5 and compound 7 exhibited moderate to good
inhibitory activities against a panel of Gram-positive bacteria with
ꢀ16
l
ꢀ16
l
g/mL, and inhibit the growth of both Vancomycin-resistant
and susceptible E. faecalis with MICs of ꢀ8
lg/mL. These findings
indicate cleistrioside-5 and compound 7 might have the potential
to avoid antibiotic cross-resistance, although their antibacterial
activities are not at the same level as those of Vancomycin and
Oxacillin in the current evaluation.
MICs of ꢀ32
lg/mL. Interestingly, these two compounds displayed
similar antibacterial profiles in general and showed selectivity to-
Comparing of the antibacterial activities of compounds 1–10
and cleistrioside-5 with those of cleistrioside 1–6 and cleistetro-
side 1–8, which have been reported previously,11 preliminary SARs
wards bacterial species. For instance, they had significant bacterial
growth inhibitory activities against two strains of
a-haemolytic

N. Ding et al. / Carbohydrate Research 346 (2011) 2126–2135
2129
Table 1
Selected antibacterial activities of the synthetic compounds and cleistrioside-5
Organism
Antibiotic resistant/susceptible (+)/(ꢂ)a
MICe
(lg/mL)
b
C5
7
10
Vc
—
Od
Escherichia coli
ATCC 25922
>32
>32
>32
4
Staphylococcus aureus
ATCC 43300
ATCC 29213
07L007
07C089
07C138
Methicillin (+)
Oxacillin (ꢂ)
>16
16
16
16
16
16
16
16
16
16
16
16
>32
>32
>32
>32
>32
>32
2
2
2
2
2
2
2
1
—
—
0.5
0.5
Methicillin (+)
Methicillin (+)
Methicillin (ꢂ)
Methicillin (–)
07T083
Staphylococcus haemolyticus
Staphylococcus epidermidis
07N024
07G024
32
>32
>32
>32
>32
>32
2
2
0.5
0.5
07T220
07T030
07N128
07Q477
07U273
Methicillin (+)
Methicillin (+)
Methicillin (ꢂ)
Methicillin (ꢂ)
Methicillin (ꢂ)
16
16
16
16
16
16
16
16
16
16
>32
>32
>32
>32
>32
2
2
2
2
2
—
—
0.5
0.5
1
Enterococcus faecalis
07K142
ATCC 29212
Vancomycin (ꢂ)
Ampicillin (ꢂ)
8
8
8
8
32
32
2
2
—
1
Vancomycin (ꢂ)
Vancomycin (ꢂ)
Vancomycin (+)
Vancomycin (+)
07K019
ZB11
ZB119
8
8
8
8
8
8
32
>32
>32
2
—
—
—
—
—
a-Haemolytic streptococci
07H198
07H219
4
4
4
4
32
32
2
2
0.5
0.5
b-Haemolytic streptococci
07U083
07U084
07U087
4
8
8
4
8
8
>32
>32
>32
2
—
—
0.5
0.5
0.5
a
Antibiotic susceptibility was assessed by MIC method which was performed by the agar dilution method described by the NCCLS. Antibiotic resistant: (+), antibiotic
susceptible: (ꢂ).
b
C5 = cleistrioside-5.
V = Vancomycin.
O = Oxacillin.
c
d
e
—, No antibacterial activities was displayed when Vancomycin (2 lg/mL) and Oxacillin (0.5 lg/mL) were used.
could be concluded. The partial presence of acetyl groups on these
rhamnoside derivatives is necessary for the antibacterial activities.
For example, compounds 2 and 6, which are the peracetates of
active compounds cleistetroside-2 and cleistrioside-5, lacked anti-
bacterial activity. Additionally, the positions of acetyl groups are
also important, especially for the 2-position of the third rhamnose
unit and the 3-position of the terminal rhamnose. Removal of the
acetyl moiety from the 2000-OH group in active compounds cleiste-
troside-2 and cleistrioside-5 (resulting in compounds 1 and 3,
respectively) led to the loss of activity, whereas blocking the 3-
OH group of the terminal rhamnose in compound 7 with an acetyl
group (resulting in compound 8) eliminated antibacterial activity.
In addition, the dirhamnoside derivative 7, which exhibited
antibacterial activities as good as cleistrioside-5 against a panel
of Gram-positive bacteria, suggest the sugar chain length could
be reduced to two without affected the activity. This finding is
attractive as dirhamnoside derivative 7 is easier to be accessed
and modified by chemists, compared to longer structures. Further
studies that focus on compound 7 are currently underway and will
be reported later.
species without being affected by the antibiotic-resistant/suscepti-
ble properties of a certain species, which suggested they might
have the potential to avoid antibiotic cross-resistance. In addition,
preliminary SARs of this type of oligorhamnoside derivatives on
the antibacterial activities were concluded. The rhamnoside deriv-
ative 7, with a reduced sugar chain, was a potent lead compound to
be further optimized as an antibacterial agent and these studies are
currently underway.
4. Experimental
4.1. General methods
Solvents were purified in a conventionalmanner. Thin layer chro-
matography (TLC)wasperformedonprecoatedE. MerckSilicaGel 60
F254 plates. Flash column chromatography was performed on silica
gel (200–300 mesh, Qingdao, China). Optical rotations were deter-
minedwitha Perkin–Elmer Model241MCpolarimeter. NMRspectra
were taken on a JEOL JNM-ECP 600 spectrometer with tetramethyl-
silane as the internal standard, and chemical shifts are recorded in d
values. COSY, HMQC, and HMBC were routinely used to definitively
assignthesignalsof 1HNMRand13CNMRspectra. Massspectra were
3. Conclusions
measured using a HP5989A or VG Quattro MALDI-TOF-MS with
cyano-4-hydroxycinnamic acid (CCA) as the matrix.
a-
A series of novel oligorhamnoside derivatives (1–10) and
cleistrioside-5, which was isolated from Cleistopholis patens were
synthesized and evaluated for their in vitro antibacterial activities.
Among them, dirhamnoside derivative compound 7 and cleistrio-
side-5 displayed similar antibacterial profiles in general and exhib-
ited moderate to good inhibitory activities on bacterial growth
against a panel of Gram-positive bacteria. The results also revealed
that these two compounds showed selectivity towards bacteria
4.2. General method A for the glycosylation of disaccharide
acceptor 11 with thioglycosides 12, 15, 18–20 and glycosylation
of monosaccharide donor 18 with acceptor 25
To a solution of thioglycoside donor (1.2 mmol for 12, 18, 19,
20; 1.6 equiv for 15) in dry CH2Cl2 (15 mL) 4 Å molecular sieves

2130
N. Ding et al. / Carbohydrate Research 346 (2011) 2126–2135
and 1 mmol disaccharide acceptor 11 or 25 (1.0 mmol) were
added. After stirred for 30 min at room temperature, the mixture
was cooled to 0 °C and NIS (1.6 equiv), AgOTf (0.2 equiv) were
added. The reaction mixture was kept at 0 °C for 30 min and then
warmed to room temperature. When TLC showed complete con-
version of 11, the reaction mixture was filtered and concentrated.
The residue was diluted with CH2Cl2 (50 mL) and washed with
5% aqueous Na2S2O3 (25 mL), saturated aqueous NaHCO3 (25 mL)
and brine (2 ꢃ 25 mL). The organic layer were combined and dried
over Na2SO4, and then concentrated under reduced pressure. The
residue was purified by silica gel column chromatography to afford
the product.
1.29 (br s, 16H, (CH2)8), 1.27 (d, 3H, J = 6.4 Hz, 6-Me), 1.15 (d, 3H,
J = 6.0 Hz, 600-Me), 1.14 (d, 3H, J = 6.0 Hz, 60-Me), 0.89 (t, 3H,
J = 6.9 Hz, CH2CH3); 13C NMR (150 MHz, CD3OD) d 172.3, 172.2,
172.1, 103.0, 101.4, 100.7, 81.3, 78.4, 75.3, 74.1, 73.9, 73.2, 72.8,
72.0, 68.6, 68.5, 68.03, 68.01, 68.0, 33.1, 30.7–30.4, 27.3, 23.7,
21.0, 20.9, 20.8, 18.7, 17.8, 17.6, 14.5; HRESIMS: m/z calcd for
C
36H62O16Na+ 773.3930; found 773.3919.
4.6. Dodecanyl 4-O-acetyl-
acetyl- -rhamnopyranosyl-(1?3)-4-O-acetyl-
rhamnopyranosyl-(1?4)- -rhamnopyranoside (1)
a-L-rhamnopyranosyl-(1?3)-4-O-
a
-L
a-L-
a
-L
The Lev protecting groups on compound 4 were removed fol-
lowing the general procedure B to afford dodecanyl 4-O-acetyl-
4.3. General method B for removal of the Lev protecting groups
2,3-O-isopropylidene-
a-
L
-rhamnopyranosyl-(1?3)-4-O-acetyl-
a-
To a stirred solution of Lev protected compound (1.0 mmol) in
CH2Cl2 (10 mL) and CH3OH (10 mL) was added NH2NH2ꢁHOAc
(19 mmol). After stirring at room temperature for 2 h, the reaction
mixture was concentrated. The residue was purified by silica gel
column chromatography to afford the product.
L
-rhamnopyranosyl-(1?3)-4-O-acetyl-a-L
-rhamnopyranosyl-
(1?4)-2,3-O-isopropylidene-a-L-rhamnopyranoside. Yield: 58%; Rf
0.63 (1:1 petroleum ether–EtOAc); ½a D20
ꢄ
ꢂ40.4 (c 0.10, CHCl3); 1H
NMR (600 MHz, DMSO-d6) d 5.41 (d, 1H, J = 5.0 Hz, 20-OH), 5.36
(d, 1H, J = 4.1 Hz, 200-OH), 5.14 (s, 1H, H-10), 4.99 (s, 1H, H-100),
4.94 (t, 1H, J = 9.8 Hz, H-40), 4.91 (s, 1H, H-1000), 4.90 (t, 1H,
J = 9.6 Hz, H-400), 4.68 (s, 1H, H-1), 4.66 (dd, 1H, J = 10.6, 8.2 Hz,
H-400), 4.13–4.10 (m, 2H, H-3 and H-3000), 4.06 (d, 1H, J = 5.9 Hz, H-
2000), 3.98–3.95 (m, 1 H, H-500), 3.96 (d, 1H, J = 5.0 Hz, H-2), 3.92–
3.89 (m, 1H, H-5000), 3.88 (dd, 1H, J = 10.1, 3.2 Hz, H-300), 3.78 (br s,
1H, H-20), 3.68–3.65 (m, 2H, H-30 and H-50), 3.61 (br s, 1H, H-200),
3.60–3.57 (m, 2H, H-5 and OCHH), 3.42–3.35 (m, 2H, H-4 and
OCHH), 2.08, 2.04, 2.02 (3s, each 3H, 3 ꢃ CH3CO), 1.53–1.51 (m,
2H, OCH2CH2), 1.43, 1.41, 1.28, 1.26 (4s, each 3H, 2 ꢃ C(CH3)2),
1.24 (br s, 18H, (CH2)9), 1.18 (d, 3H, J = 6.4 Hz, 6-Me), 1.06 (d, 3H,
J = 6.0 Hz, 60-Me), 1.03 (d, 3H, J = 6.4 Hz, 600-Me), 1.01 (d, 3H,
J = 6.4 Hz, 6000-Me), 0.85 (t, 3H, J = 7.1 Hz, CH2CH3); 13C NMR
(150 MHz, CDCl3) d 170.1, 170.0, 169.8, 109.8, 109.4, 100.7, 99.0,
98.0, 96.8, 78.4, 77.9, 77.7, 76.5, 76.3, 75.8, 75.4, 73.8, 72.4, 71.0,
70.9, 67.8, 67.1, 66.7, 65.2, 63.7, 31.9, 29.7–29.3, 27.9, 27.5, 26.3,
26.2, 26.1, 22.7, 21.0, 20.8, 18.0, 17.4, 17.3, 16.8, 14.1; ESIMS: calcd
for [M+Na]+ m/z 999.5; found: 999.6.
4.4. General method C for removal of the isopropylidene
protecting groups
The isopropylidene protected compound (0.1 mmol) was dis-
solved in 80% HOAc (15 mL) and stirred for 1–2 h at 80 °C. The
reaction mixture was concentrated and the residue was purified
by silica gel column chromatography to give the product.
4.5. Dodecanyl 2,4-di-O-acetyl-
O-acetyl- -rhamnopyranosyl-(1?4)-
(cleistrioside-5)
a
-
L
-rhamnopyranosyl-(1?3)-4-
a
-L
a-L-rhamnopyranoside
The Lev protecting groups in compound 13 were removed fol-
lowing the general procedure B to afford dodecanyl 2,4-di-O-acet-
yl-a-L-rhamnopyranosyl-(1?3)-4-O-acetyl-a-L-rhamnopyranosyl-
(1?4)-2,3-O-isopropylidene-a-L-rhamnopyranoside. Yield: 83%; Rf
0.53 (1:2 petroleum ether–EtOAc); ½a D20
ꢄ
ꢂ54.7 (c 0.10, CHCl3); 1H
The isopropylidene protecting groups on the above compound
were removed following the general procedure C to afford com-
NMR (600 MHz, DMSO-d6) d 5.46 (d, 1H, J = 4.6 Hz, 20-OH), 5.28
(d, 1H, J = 5.9 Hz, 300-OH), 5.13 (s, 1H, H-10), 4.94 (t, 1H, J = 9.9 Hz,
H-40), 4.91 (s, 1H, H-1), 4.78 (d, 1H, J = 3.8 Hz, H-200), 4.74 (s, 1H,
H-100), 4.71 (t, 1H, J = 9.8 Hz, H-400), 4.19–4.05 (m, 2H, H-2 and H-
3), 3.95–3.90 (m, 2H, H-300 and H-500), 3.75 (br s, 1H, H-20), 3.68
(dd, 1H, J = 10.1, 5.3 Hz, H-30), 3.66–3.62 (m, 1H, H-50), 3.59–3.53
(m, 2H, H-5 and OCHH), 3.41–3.35 (m, 2H, H-4 and OCHH), 2.07,
2.06, 2.05 (3s, each 3H, 3 ꢃ COCH3), 1.54–1.49 (m, 2H, OCH2CH2),
1.43, 1.27 (2s, each 3H, 2 ꢃ CH3), 1.24 (br s, 18H, (CH2)9), 1.17 (d,
3H, J = 6.4 Hz, 6-Me), 1.06 (d, 3H, J = 6.4 Hz, 60-Me), 1.04 (d, 3H,
J = 5.9 Hz, 600-Me), 0.85 (t, 3H, J = 7.1 Hz, Me); 13C NMR (150 MHz,
DMSO-d6) d 170.0, 169.9, 108.6, 99.6, 98.3, 96.1, 77.8, 76.9, 76.6,
75.6, 73.5, 72.3, 71.9, 69.9, 66.8, 66.6, 66.1, 65.6, 63.3, 31.3, 28.9–
28.6, 27.7, 26.1, 25.6, 22.1, 20.9, 20.8, 20.5, 17.9, 17.2, 14.0; ESIMS:
calcd for [M+Na]+ m/z 813.4; found: 813.5.
pound 1. Yield: 70%; Rf 0.43 (8:1, CHCl3–MeOH); ½a D20
ꢂ80.2 (c
ꢄ
1
0.10, MeOH); H NMR (600 MHz, CD3OD) d 5.21 (br s, 1H, H-10),
5.09 (t, 1H, J = 9.9 Hz, H-40), 5.05 (t, 1H, J = 9.9 Hz, H-400), 4.92 (t,
1H, J = 7.8 Hz, H-4000), 4.82 (br s, 1H, H-100), 4.81 (br s, 1H, H-1000),
4.63 (br s, 1H, H-1), 4.08 (br s, 1H, H-20), 4.04 (dd, 1H, J = 10.1,
3.2 Hz, H-300), 4.05–4.01 (m, 1H, H-5), 3.93–3.86 (m, 2H, H-50 and
H-500), 3.91 (dd, 1H, J = 9.6, 3.2 Hz, H-3000), 3.90 (dd, 1H, J = 9.6,
3.2 Hz, H-30), 3.83 (br s, 1H, H-200), 3.74 (br s, 1H, H-2000), 3.73 (dd,
1H, J = 8.7, 2.8 Hz, H-3), 3.72 (d, 1H, J = 2.8 Hz, H-2), 3.68–3.62
(m, 2H, H-5 and OCHH), 3.51 (t, 1H, J = 9.2 Hz, H-4), 3.41–3.37
(m, 1H, OCHH), 2.07 (s, 9H, 3 ꢃ CH3CO), 1.58–1.56 (m, 2H,
OCH2CH2), 1.29 (br s, 18H, (CH2)9), 1.27 (d, 3H, J = 6.0 Hz, 6-Me),
1.15 (d, 3H, J = 6.0 Hz, 60-Me), 1.14 (d, 3H, J = 6.0 Hz, 600-Me), 1.13
(d, 3H, J = 6.0 Hz, 6000-Me), 0.89 (t, 3H, J = 6.9 Hz, CH2CH3); 13C
NMR (150 MHz, CD3OD) d 172.5, 172.0, 171.7, 103.9, 103.8,
103.1, 101.4, 81.3, 78.8, 78.1, 75.5, 74.1, 74.0, 73.2, 72.8, 72.4,
72.1, 72.0, 70.1, 68.6, 68.5, 68.4, 68.1, 33.1, 30.8–30.5, 27.3, 23.8,
21.0, 21.0, 20.9, 18.7, 17.7, 17.7, 17.6, 14.5; HRESIMS: m/z calcd
for C36H62O16Na+ 919.4509; found 919.4514.
The isopropylidene protecting group on the above compound
was removed following the general procedure C to afford cleistrio-
side-5. Yield: 70%; Rf 0.48 (8:1, CHCl3–MeOH); ½a D20
ꢂ43.5 (c 0.04,
ꢄ
MeOH); 1H NMR (600 MHz, CD3OD) d 5.21 (d, 1H, J = 1.7 Hz, H-10),
5.09 (t, 1H, J = 9.6 Hz, H-40), 4.92 (dd, 1H, J = 3.8,1.6 Hz H-200), 4.88
(tobsc, 1H, H-400), 4.86 (d, 1H, J = 1.7 Hz, H-100), 4.63 (d, 1H, J = 1.1 Hz,
H-1), 4.12 (dd, 1H, J = 9.9, 3.3 Hz, H-300), 4.04 (dd, 1H, J = 2.8, 1.6 Hz,
H-20), 4.00–3.95 (m, 1H, H-500), 3.87 (dd, 1H, J = 9.9, 3.2 Hz, H-30),
3.90–3.85 (m, 1H, H-50), 3.73 (dd, 1H, J = 9.0, 3.3 Hz, H-3), 3.72
(dd, 1H, J = 3.3, 1.7 Hz, H-2), 3.67–3.64 (m, 1H, OCHH), 3.64–3.60
(m, 1H, H-5), 3.50 (t, 1H, J = 9.1 Hz, H-4), 3.40–3.37 (m, 1H, OCHH),
2.12 (s, 3H, CH3CO-40), 2.11 (s, 3H, CH3CO-200), 2.08 (s, 3H, CH3CO-
400), 1.62–1.53 (m, 2H, OCH2CH2), 1.37–1.34 (m, 2H, OCH2CH2CH2),
4.7. Dodecanyl tri-O-acetyl-
4-di-O-acetyl- -rhamnopyranosyl-(1?3)-2,4-di-O-
acetyl- -rhamnopyranosyl-(1?4)-2,3-di-O-acetyl-
rhamnopyranoside (2)
a-L-rhamnopyranosyl-(1?3)-2,
a-L
a
-L
a-L-
To a solution of compound 1 (25 mg, 0.03 mmol) in dry CH2Cl2
(10 mL), Ac2O (20.1 L, 0.20 mmol), Et3N (33.2 L, 0.24 mmol) and
l
l

N. Ding et al. / Carbohydrate Research 346 (2011) 2126–2135
2131
DMAP (2.0 mg, 0.016 mmol) were added under argon. The reaction
mixture was stirred for 12 h and then quenched by the addition of
MeOH (30 mL). The mixture was concentrated and the residue was
purified by silica gel column chromatography (10:1?3:1 petro-
leum ether–EtOAc) to give 2 (32.5 mg, 99%) as a gummy solid: Rf
72.0, 70.0, 68.5, 68.1, 68.0, 33.1, 30.8–30.4, 27.3, 23.7, 21.0, 20.9,
18.7, 17.8, 17.7, 14.5; HRESIMS: m/z calcd for C34H60O15Na+
731.3824; found 731.3826.
4.9. Dodecanyl 4-O-benzoyl-
a-
L-rhamnopyranosyl-(1?3)-4-O-
0.29 (3:2 petroleum ether–EtOAc); ½a D20
ꢄ
ꢂ33.2 (c 0.10, CHCl3); 1H
acetyl- -rhamnopyranosyl-(1?4)-a-L
a
-
L
-rhamnopyranoside (4)
NMR (600 MHz, CDCl3) d 5.24 (dd, 1H, J = 9.7, 3.7 Hz, H-3), 5.21
(dd, 1H, J = 3.2, 1.8 Hz, H-2), 5.14 (dd, 1H, J = 10.1 3.2 Hz, H-300),
5.07 (t, 1H, J = 9.8 Hz, H-40), 5.06 (t, 1H, J = 10.1 Hz, H-400), 5.02 (t,
1H, J = 9.8 Hz, H-4000), 5.05 (dd, 1H, J = 3.2, 1.9 Hz, H-2000), 5.01 (dd,
1H, J = 2.7, 2.0 Hz, H-20), 4.97 (dd, 1H, J = 3.2, 1.8 Hz, H-200), 4.94
(d, 1H, J = 1.4 Hz, H-10), 4.85 (d, 1H, J = 1.4 Hz, H-100), 4.84 (d, 1H,
J = 1.4 Hz, H-1000), 4.65 (d, 1H, J = 1.4 Hz, H-1), 3.98 (dd, 1H, J = 9.6,
3.2 Hz, H-30), 3.91 (dd, 1H, J = 10.1, 3.2 Hz, H-30), 3.91–3.86 (m,
1H, H-50), 3.83–3.78 (m, 2H, H-5 and H-5000), 3.73–3.68 (m, 1H, H-
500), 3.64 (t, 1H, J = 9.4 Hz, H-4), 3.66–3.64 (m, 1H, OCHH), 3.42–
3.38 (m, 1H, OCHH), 2.18, 2.17, 2.14, 2.13, 2.12, 2.11, 2.07, 2.04,
1.97 (9s, each 3H, 9 ꢃ CH3CO), 1.62–1.56 (m, 2H, OCH2CH2), 1.34
(d, 3H, J = 5.9 Hz, 6-Me), 1.26 (br s, 18H, (CH2)9), 1.20 (d, 3H,
J = 6.4 Hz, 60-Me), 1.17 (d, 3H, J = 5.9 Hz, 6000-Me), 1.16 (d, 3H,
J = 6.4 Hz, 600-Me), 0.88 (t, 3H, J = 7.1 Hz, CH2CH3); 13C NMR
(150 MHz, CDCl3) d 170.5, 170.2–170.0, 169.7, 99.2, 99.1, 98.8,
97.3, 79.3, 75.3, 74.8, 72.0, 71.7, 71.6, 71.5, 71.4, 70.7, 70.2, 70.0,
68.5, 68.3, 67.5, 67.4, 67.1, 66.6, 31.9, 29.7–29.3, 26.0, 22.7, 21.0–
20.7, 18.1, 17.2, 17.1, 17.0, 14.1; HRESIMS: m/z calcd for
The Lev protecting group on compound 23 was removed follow-
ing the general procedure B to afford Dodecanyl 4-O-benzoyl-2,3-
O-isopropylidene-a-L-rhamnopyranosyl-(1?3)-4-O-acetyl-a-L-
rhamnopyranosyl-(1?4)-2,3-O-isopropylidene-a-L-rhamnopyr-
anoside. Yield: 87%; Rf 0.50 (2:1 petroleum ether–EtOAc); ½a D20
ꢄ
ꢂ61.6 (c 0.15, CHCl3); 1H NMR (600 MHz, CDCl3) d 8.05 (d, 2H,
J = 8.4 Hz, Ph), 7.58 (t, 1H, J = 7.3 Hz, Ph), 7.45 (t, 1H, J = 7.1 Hz,
Ph), 5.40 (d, 1H, J = 1.4 Hz, H-10), 5.19 (s, 1H, H-100), 5.12 (t, 1H,
J = 9.7 Hz, H-40), 5.11 (t, 1H, J = 9.9 Hz, H-400), 4.95 (s, 1H, H-1),
4.36 (dd, 1H, J = 7.7, 5.5 Hz, H-300), 4.16 (dd, 1H, J = 7.3, 5.9 Hz, H-
3), 4.14 (d, 1H, J = 5.5 Hz, H-2), 4.09 (d, 1H, J = 5.5 Hz, H-200), 4.04
(dd, 1H, J = 2.9, 1.4 Hz, H-20), 3.99 (dd, 1H, J = 9.5, 3.3 Hz, H-30),
3.98–3.95 (m, 1H, H-50), 3.86–3.82 (m, 1H, H-500), 3.72–3.66 (m,
2H, OCHH and H-5), 3.51 (dd, 1H, J = 9.9, 7.3 Hz, H-4), 3.44–3.40
(m, 1H, OCHH), 2.12 (s, 3H, COCH3), 1.60, 1.53, 1.34, 1.32 (4s, each
3H, 4 ꢃ CH3), 1.58–1.55 (m, 2H, OCH2CH2), 1.29 (d, 3H, J = 6.2 Hz, 6-
CH3), 1.26 (br s, 18H, (CH2)9), 1.22 (d, 3H, J = 6.2 Hz, 600-CH3), 1.21
(d, 3H, J = 6.2 Hz, 60-CH3), 0.88 (t, 3H, J = 7.1 Hz, CH3); 13C NMR
(150 MHz, CDCl3) d 170.1, 165.7, 133.3, 130.1, 129.8, 129.6,
128.4, 109.9, 109.5, 99.4, 98.0, 96.8, 78.4, 77.9, 76.2, 76.0, 75.5,
74.5, 72.7, 71.3, 67.8, 66.7, 65.1, 63.7, 60.4, 31.9, 29.6–29.3, 27.9,
27.6, 26.4, 26.3, 26.1, 22.7, 20.9, 18.0, 17.3, 17.1, 14.1; ESIMS: calcd
for [M+Na]+ m/z 873.4; found: 873.3.
C
36H62O16Na+ 1171.5143; found 1171.5144.
4.8. Dodecanyl 4-O-acetyl-
a
-
L
-rhamnopyranosyl-(1?3)-4-O-
-rhamnopyranoside (3)
acetyl- -rhamnopyranosyl-(1?4)-a-L
a-
L
The Lev protecting group on compound 25 was removed follow-
ing the general procedure B to afford dodecanyl 4-O-acetyl-2,3-O-
The isopropylidene protecting groups on the above compound
were removed following the general procedure C to afford com-
isopropylidene-
a
-L
-rhamnopyranosyl-(1?3)-4-O-acetyl-
a-
L-
pound 4. Yield: 83%; Rf 0.55 (8:1, CHCl3–MeOH); ½a D20
ꢂ75.4 (c
ꢄ
rhamnopyranosyl-(1?4)-2,3-O-isopropylidene-
a
-
L
-rhamnopyr-
0.05, CHCl3); 1H NMR (600 MHz, CDCl3) d 8.03 (d, 2H, J = 7.7 Hz,
Ph), 7.56 (t-like, 1H, J = 7.7, 7.1 Hz, Ph), 7.42 (t-like, 1H, J = 7.4,
7.1 Hz, Ph), 5.28 (s, 1H, H-100), 5.08 (t, 1H, J = 9.4 Hz, H-40), 5.07 (t,
1H, J = 9.4 Hz, H-400), 5.04 (s, 1H, H-10), 4.73 (s, 1H, H-1), 4.19 (br
s, 1H, H-20), 4.17–4.09 (m, 2H, H-50 and H-300), 3.99 (dd, 1H,
J = 9.4, 3.1 Hz, H-30), 3.94 (br s, 1H, H-200), 3.92–3.87 (m, 2H, H-500
and H-3), 3.86 (s, 1H, H-2), 3.69–3.61 (m, 2H, H-5 and OCHH),
3.51 (t, 1H, J = 8.8 Hz, H-4), 3.39–3.35 (m, 1H, OCHH), 3.14–2.84
(m, 5H, 5 ꢃ OH), 2.08 (s, 3H, COCH3), 1.56–1.53 (m, 2H, OCH2CHH),
1.31 (d, 3H, J = 6.0 Hz, 6-Me), 1.26 (br s, 18H, (CH2)9), 1.18 (d, 6H,
J = 6.0 Hz, 600-Me and 60-Me), 0.88 (t, 3H, J = 7.1 Hz, CH3); 13C NMR
(150 MHz, CDCl3) d 173.9, 167.4, 133.5, 129.9, 129.3, 128.5,
103.3, 100.8, 100.7, 99.3, 75.5, 72.8, 72.6, 72.0, 71.6, 71.0, 70.7,
69.9, 67.9, 67.1, 66.9, 66.3, 65.8, 31.9, 29.6–29.3, 26.1, 22.7, 20.9,
anoside. Yield: 72%; Rf 0.56 (1:2 petroleum ether–EtOAc,); ½a D20
ꢄ
ꢂ60.4 (c 0.10, CHCl3); 1H NMR (600 MHz, DMSO-d6) d 5.36 (d,
1H, J = 4.6 Hz, 20-OH), 5.13 (s, 1H, H-100), 5.05 (s, 1H, H-10), 4.93 (t,
1H, J = 9.8 Hz, H-4’), 4.91 (s, 1H, H-1), 4.61 (dd, 1H, J = 10.1,
7.7 Hz, H-400), 4.12–4.08 (m, 2H, H-3 and H-300), 4.06 (d, 1H,
J = 5.5 Hz, H-200), 3.96 (d, 1H, J = 5.5 Hz, H-2), 3.96–3.93 (m, 1H,
H-500), 3.79 (d, 1H, J = 4.6 Hz, H-20), 3.78 (br d, 1H, J = 7.8 Hz, H-
30), 3.71–3.66 (m, 1H, H-50), 3.60–3.54 (m, 2H, H-5 and OCHH),
3.42–3.38 (m, 1H, OCHH), 3.36 (dd, 1H, J = 9.7, 7.4 Hz, H-4), 2.07,
2.04 (2s, each 3H, 2 ꢃ COCH3), 1.53–1.51 (m, 2H, OCH2CH2), 1.43,
1.41, 1.27, 1.26 (4s, each 3H, 4 ꢃ CH3), 1.24 (br s, 18H, (CH2)9),
1.19 (d, 3H, J = 6.4 Hz, 6-Me), 1.06 (d, 3H, J = 6.4 Hz, 60-Me), 1.02
(d, 3H, J = 6.4 Hz, 600-Me), 0.85 (t, 3H, J = 6.9 Hz, CH2CH3); 13C
NMR (150 MHz, DMSO-d6) d 169.8, 108.8, 108.6, 98.5, 98.3, 96.1,
77.8, 76.9, 76.6, 75.5, 74.8, 73.9, 72.2, 70.0, 66.8, 66.6, 63.6, 63.3,
31.3, 28.9–28.6, 27.7, 27.5, 26.1, 25.6, 22.1, 20.7, 20.6, 17.9, 17.3,
16.6, 14.0; ESIMS: calcd for [M+Na]+ m/z 811.5; found: 811.5.
The isopropylidene protecting groups on the above compound
were removed following the general procedure C to afford com-
18.1, 17.5, 17.3, 14.1; HRESIMS: calcd for
793.3981; found, 793.3958.
C
39H62O15Na+
4.10. Dodecanyl 4-O-n-hexanoyl-
a
-L
-rhamnopyranosyl-(1?3)-
4-O-acetyl-
a-L
-rhamnopyranosyl-(1?4)- -rhamnopyranoside
a-L
(5)
pound 3. Yield: 81%; Rf 0.56 (5:1, CHCl3–MeOH); ½a D20
ꢂ35.2 (c
ꢄ
0.10, MeOH); 1H NMR (600 MHz, CD3OD) d 5.21 (d, 1H, J = 1.9 Hz,
H-10), 5.08 (t, 1H, J = 9.9 Hz, H-40), 4.92 (t, 1H, J = 9.8 Hz, H-400),
4.84 (d, 1H, J = 1.4 Hz, H-100), 4.63 (d, 1H, J = 1.4 Hz, H-1), 4.07
(dd, 1H, J = 2.7, 1.8 Hz, H-20), 3.98–3.94 (m, 1H, H-500), 3.91–3.87
(m, 3H, H-30, H-300 and H-500), 3.76–3.72 (m, 3H, H-200, H-2 and H-
3), 3.68–3.61 (m, 2H, H-5 and OCHH), 3.51 (t, 1H, J = 9.2 Hz, H-4),
3.41–3.40 (m, 1H, OCHH), 2.09, 2.07 (2s, each 3H, 2 ꢃ COCH3),
1.61–1.55 (m, 2H, OCH2CH2), 1.39–1.34 (m, 2H, OCH2CH2CH2),
1.29 (br s, 16H, (CH2)8), 1.27 (d, 3H, J = 6.4 Hz, 6-Me), 1.14 (d, 6H,
J = 6.4 Hz, 60-Me and 600-Me), 1.02 (d, 3H, J = 6.4 Hz, 6000-CH3), 0.89
(t, 3H, J = 6.9 Hz, CH2CH3); 13C NMR (150 MHz, CD3OD) d 1172.5,
171.9, 103.7, 103.1, 101.4, 81.3, 78.2, 75.4, 74.2, 73.2, 72.8, 72.4,
The Lev protecting group on compound 24 was removed follow-
ing the general procedure B to afford dodecanyl 4-O-n-hexanoyl-
2,3-O-isopropylidene-a-L-rhamnopyranosyl-(1?3)-4-O-acetyl-a-
L
-rhamnopyranosyl-(1?4)-2,3-O-isopropylidene-a-L-rhamnopyr-
anoside. Yield: 90%; Rf 0.48 (2:1 petroleum ether–EtOAc); ½a D20
ꢄ
ꢂ42.3 (c 0.08, CHCl3); 1H NMR (600 MHz, CDCl3) d 5.25 (s, 1H,
H-10), 5.04 (t, 1H, J = 9.4 Hz, H-40), 4.98 (s, 1H, H-100), 4.83 (t, 1H,
J = 9.4 Hz, H-400), 4.74 (s, 1H, H-1), 4.13 (s, 1H, H-2), 3.99–3.87
(m, 7H), 3.70–3.63 (m, 2H), 3.50 (t, 1H, J = 9.4 Hz, H-4), 3.41–
3.37 (m, 1H, OCHH), 2.96–2.82 (br s, 5H, OH), 2.41–2.29 (m, 2H,
CHHCO), 2.09 (s, 3H, CH3CO), 1.68–1.62 (m, 2H, CHHCH2CO),
1.58–1.55 (m, 2H, OCH2CHH), 1.31 (d, 3H, J = 6.0 Hz, 6-Me), 1.26

2132
N. Ding et al. / Carbohydrate Research 346 (2011) 2126–2135
(m, 22 H), 1.21 (d, 3H, J = 6.4 Hz, 60-Me), 1.19 (d, 3H, J = 6.3 Hz, 600-
Me), 0.93 (t, 3H, J = 7.0 Hz, CH3); 0.88 (t, 3H, J = 6.7 Hz, CH3); 13C
NMR (150 MHz, CDCl3) d 172.9, 170.0, 109.7, 109.4, 99.2, 98.0,
96.8, 78.5, 77.9, 76.3, 75.9, 75.5, 73.6, 72.7, 71.3, 67.8, 66.7, 65.0,
63.7, 34.3, 31.9, 31.2, 29.6–29.3, 27.9, 27.6, 26.4, 26.3, 26.1,
24.5, 22.7, 22.3, 20.9, 18.0, 17.3, 17.1, 14.1, 13.9; ESIMS: calcd
for [M+Na]+ m/z 867.5; found: 867.7.
7.3 Hz, H-4), 3.43–3.40 (m, 2H, H-5 and OCHH), 3.51 (t, 1H,
J = 9.2 Hz, H-4), 3.40–3.36 (m, 1H, OCHH), 2.11 (s, 3H, COCH3),
158–1.53 (m, 2H, OCH2CH2), 1.30 (d, 3H, J = 6.0 Hz, 6-Me), 1.26
(br s, 18H, (CH2)9), 1.18 (d, 3H, J = 6.4 Hz, 60-Me), 0.88 (t, 3H,
J = 7.1 Hz, CH2CH3); 13C NMR (150 MHz, CDCl3) d 171.5, 101.9,
99.6, 81.2, 74.4, 72.1, 71.5, 70.9, 69.5, 67.7, 66.9, 66.6, 31.9, 29.7–
29.3, 26.1, 22.7, 21.1, 17.9, 17.2, 14.1; HRESIMS: m/z calcd for
The isopropylidene protecting groups on the above compound
were removed following the general procedure C to afford com-
C
26H48O10Na+ 543.3140; found 543.3142.
pound 5. Yield: 63%; Rf 0.42 (8:1, CHCl3–MeOH); ½a D20
ꢄ
ꢂ64.9 (c
4.13. Dodecanyl 3,4-di-O-acetyl-2-O-levulinyl-
a-L-
1
0.09, CHCl3); H NMR (CDCl3, 600 MHz) d 5.25 (s, 1H, H-10), 5.04
(t, 1H, J = 9.4 Hz, H-40), 4.98 (s, 1H, H-100), 4.83 (t, 1H, J = 9.4 Hz,
H-400), 4.74 (s, 1H, H-1), 4.13 (s, 1H, H-2), 3.99–3.87 (m, 7H, H-2,
H-3, H-200, H-300, H-30, H-50 and H-500), 3.70–3.63 (m, 2H, H-5 and
OCHH), 3.50 (t, 1H, J = 9.4 Hz, H-4), 3.41–3.37 (m, 1H, OCHH),
3.21–2.60 (m, 5H, 5 ꢃ OH), 2.41–2.29 (m, 2H, CHHCO), 2.09 (s,
3H, CH3CO), 1.68–1.62 (m, 2H, CHHCH2CO), 1.58–1.55 (m, 2H,
OCH2CHH), 1.31 (d, 3H, J = 6.0 Hz, 6-Me), 1.26 (br s, 22H, (CH2)2
and (CH2)9), 1.21 (d, 3H, J = 6.4 Hz, 60-Me), 1.19 (d, 3H, J = 6.3 Hz,
600-Me), 0.93 (t, 3H, J = 8.0 Hz, CH3); 0.88 (t, 3H, J = 6.7 Hz, CH3);
13C NMR (150 MHz, C5D5N–CD3OD, 6:1) d 174.9, 170.4, 100.7,
100.6, 99.3, 80.4, 72.6, 72.3, 72.0, 71.6, 71.0, 70.9, 70.7, 67.9, 67.2,
66.7, 66.3, 34.3, 31.9, 31.2, 29.7–29.3, 26.1, 24.6, 22.7, 22.3, 20.9,
18.0, 17.4, 17.3, 14.1, 13.9; HRESIMS: calcd for C38H68O15Na+
787.4450; found, 787.4449.
rhamnopyranosyl-(1?4)- -rhamnopyranoside (8)
a-L
The isopropylidene protecting group on compound 27 was re-
moved following the general procedure C to afford compound 8.
Yield: 79%; Rf 0.59 (6:1, CHCl3–MeOH); ½a D20
ꢂ64.6 (c 0.31, CHCl3);
ꢄ
1H NMR (600 MHz, CDCl3) d 5.31 (s, 1H, H-10), 5.15 (dd, 1H, J = 9.6,
2.8 Hz, H-30), 5.14 (d, 1H, J = 2.8 Hz, H-20), 5.11 (t, 1H, J = 9.4 Hz, H-
40), 4.73 (s, 1H, H-1), 4.19 (br s, 1H, 20-OH), 3.98–3.93 (m, 1H, H-50),
3.87 (br s, 2H, H-2 and H-3), 3.82 (br s, 1H, 2-OH), 3.74 (br s, 1H, 3-
OH), 3.69–3.61 (m, 2H, H-5 and OCHH), 3.51 (t, 1H, J = 8.9 Hz, H-4),
3.40–3.36 (m, 1H, OCHH), 2.10, 2.04 (2s, each 3H, 2 ꢃ COCH3),
1.59–1.55 (m, 2H, OCH2CH2), 1.31 (d, 3H, J = 6.0 Hz, 60-Me), 1.26
(br s, 18H, (CH2)9), 1.20 (d, 3H, J = 6.0 Hz, 6-Me), 0.88 (t, 3H,
J = 6.9 Hz, CH2CH3); 13C NMR (150 MHz, CDCl3) d 170.7, 170.1,
101.1, 99.5, 80.7, 72.1, 71.6, 71.5, 71.2, 69.3, 67.8, 67.1, 66.3,
31.9, 29.6–26.3, 26.1, 22.7, 21.0, 20.8, 18.0, 17.2, 14.1; HRESIMS:
m/z calcd for C28H50O11Na+ 585.3245; found 585.3234.
4.11. Dodecanyl 2,3,4-tri-O-acetyl-
2,4-di-O-acetyl- -rhamnopyranosyl-(1?4)-2,3-di-O-acetyl-
-rhamnopyranoside (6)
a-L-rhamnopyranosyl-(1?3)-
a-
L
a-
L
4.14. p-Tolyl 3-O-levulinyl-2,4-di-O-acetyl-1-thio-a-L-
rhamnopyranoside 12
To a solution of cleistrioside-5 (29.2 mg, 0.04 mmol) in dry
CH2Cl2 (10 mL), Ac2O (31.1 L, 0.33 mmol), Et3N (51.1 L,
l
l
To a solution of p-tolyl 2,4-di-O-acetyl-1-thio-a-L-rhamnopyr-
0.37 mmol) and DMAP (2.0 mg, 0.016 mmol) were added under ar-
gon. The reaction mixture was stirred for 12 h and then quenched
by the addition of MeOH (30 mL). The mixture was concentrated
and the residue was purified by silica gel column chromatography
(1:1 petroleum ether–EtOAc) to give compound 6 (33.7 mg, 90%) as
anoside (2.0 g, 5.6 mmol) in dry CH2Cl2 (50 mL), levulinic acid
(786.1 mg, 6.8 mmol), DCC (1.4 g, 6.8 mmol) and DMAP (68.9 mg,
0.6 mmol) were added under argon. The reaction mixture was stir-
red for 12 h and then the mixture was diluted with CH2Cl2
(150 mL) and washed with H2O (100 mL), 1 M HCl (2 ꢃ 100 mL),
saturated aqueous NaHCO3 (2 ꢃ 100 mL) and brine (2 ꢃ 100 mL).
The organic phase was dried over Na2SO4 and concentrated under
reduced pressure. The residue was purified by silica gel column
chromatography (10:1 petroleum ether–EtOAc) to give 12
(2.13 g, 84%) as a white solid: Rf 0.44 (2:1 petroleum ether–EtOAc);
a syrup: Rf 0.37 (1:1 petroleum ether–EtOAc); ½a D20
ꢂ37.9 (c 0.20,
ꢄ
CHCl3); 1H NMR (600 MHz, CDCl3) d 5.24 (dd, 1H, J = 9.6, 3.2 Hz,
H-3), 5.22 (d, 1H, J = 3.2 Hz, H-2), 5.14 (dd, 1H, J = 10.1 3.2 Hz, H-
300), 5.10 (t, 1H, J = 9.6 Hz, H-400), 5.05 (t, 1H, J = 10.1 Hz, H-40),
5.04 (br s, 2H, H-20 and H-200), 4.96 (br s, 1H, H-10), 4.88 (br s, 1H,
H-100), 4.92 (dd, 1H, J = 3.8,1.6 Hz H-200), 4.88 (tobsc, 1H, H-400),
4.86 (d, 1H, J = 1.7 Hz, H-100), 4.66 (br s, 1H, H-1), 4.00 (dd, 1H,
J = 9.7, 3.2 Hz, H-30), 3.91–3.86 (m, 1H, H-500), 3.85–3.79 (m, 2H,
H-5 and H-50), 3.65 (t, 1H, J = 9.6 Hz, H-4), 3.65–3.63 (m, 1H,
OCHH), 3.42–3.38 (m, 1H, OCHH), 2.18, 2.14, 2.13, 2.12, 2.08,
2.05, 1.98 (7s, each 3H, 7 ꢃ CH3CO), 1.62–1.57 (m, 2H, OCH2CH2),
1.34 (d, 3H, J = 6.0 Hz, 6-Me), 1.26 (br s, 18H, (CH2)9), 1.21 (d, 3H,
J = 6.0 Hz, 600-Me), 1.17 (d, 3H, J = 6.0 Hz, 60-Me), 0.88 (t, 3H,
J = 6.9 Hz, CH2CH3); 13C NMR (150 MHz, CDCl3) d 170.2–170.0,
169.7, 99.2, 98.5, 97.3, 79.2, 74.8, 72.0, 71.6, 71.3, 70.7, 70.2,
70.1, 68.5, 68.3, 67.4, 67.2, 66.6, 31.9, 29.6–29.3, 26.0, 22.7, 20.9–
20.7, 18.1, 17.2, 17.1, 14.1; HRESIMS: m/z calcd for C36H62O16Na+
941.4353; found 941.4332.
½
a 2D0
ꢄ
ꢂ90.4 (c 0.10, CHCl3); 1H NMR (600 MHz, CDCl3) d 7.35 (d, 2H,
J = 8.0 Hz, PhH), 7.12 (d, 2H, J = 8.0 Hz, PhH), 5.47 (dd, 1H, J = 3.2,
1.8 Hz, H-2), 5.33 (d, 1H, J = 1.4 Hz, H-1), 5.29 (dd, 1H, J = 10.1,
3.2 Hz, H-3), 5.15 (t, 1H, J = 9.9 Hz, H-4), 4.39–4.34 (m, 1H, H-5),
2.82–2.41 (m, 4H, COCH2CH2CO), 2.32 (s, 3H, PhCH3), 2.18, 2.14,
2.13 (3s, each 3H, 3 ꢃ COCH3), 1.24 (d, 3H, J = 6.0 Hz, 6-Me); 13C
NMR (150 MHz, CDCl3)
d 206.2, 171.6, 170.2, 170.0, 138.2,
132.4, 129.9, 129.4, 86.0, 71.2, 70.8, 69.6, 67.6, 37.6, 29.7, 27.8,
21.1, 20.9, 20.8, 17.3; ESIMS: calcd for [M+Na]+ m/z 475.1; found:
475.1.
4.15. Dodecanyl 2,4-di-O-acetyl-3-O-levulinyl-
a-L-
rhamnopyranosyl-(1?3)-4-O-acetyl-2-O-levulinyl-
a-L-
rhamnopyranosyl-(1?4)-2,3-O-isopropylidene-a-L-
4.12. Dodecanyl 4-O-acetyl-2-O-levulinyl-
a
-L
-
rhamnopyranoside (13)
rhamnopyranosyl-(1?4)- -rhamnopyranoside (7)
a-L
Compound 13 was prepared from donor 12 and acceptor 11 by
The isopropylidene protecting groups on compound 26 were re-
moved following the general procedure C to afford compound 7.
method A. Yield: 81%; Rf 0.47 (1:1 petroleum ether–EtOAc); ½a D20
ꢄ
ꢂ31.8 (c 0.10, CHCl3); 1H NMR (600 MHz, CDCl3) d 5.26 (s, 1H, H-
100), 5.25 (dd, 1H, J = 3.2, 1.8 Hz, H-200), 5.18 (dd, 1H, J = 10.1,
3.7 Hz, H-30), 5.07 (t, 1H, J = 10.1 Hz, H-400), 5.06 (t, 1H, J = 9.8 Hz,
H-40), 4.99 (dd, 1H, J = 3.2, 1.9 Hz, H-20), 4.94 (s, 1H, H-1), 4.89 (d,
1H, J = 1.9 Hz, H-10), 4.16 (dd, 1H, J = 7.3, 5.5 Hz, H-3), 4.09 (dd,
J = 5.5, 1.3 Hz, H-2), 4.02 (dd, 1H, J = 9.6, 3.2 Hz, H-300), 3.99–3.96
Yield: 81%; Rf 0.44 (6:1, CHCl3–MeOH,); ½a D20
ꢂ53.8 (c 0.06, CHCl3);
ꢄ
1H NMR (600 MHz, CDCl3) d 5.17 (s, 1H, H-10), 4.87 (m, 2H, H-40and
H-30), 4.72 (s, 1H, H-1), 4.52 (br s, 1H, OH), 4.17 (br s, 1H, OH), 4.12
(br s, 1H, OH), 3.92 (br s, 1H, OH), 3.90–3.86 (m, 4H, H-2, H-20 H-3
and H-50), 3.65–3.60 (m, 2H, H-30 and H-50), 3.51 (dd, 1H, J = 9.7,

N. Ding et al. / Carbohydrate Research 346 (2011) 2126–2135
2133
(m, 1H, H-50), 3.79–3.74 (m, 1H, H-500), 3.70–3.65 (m, 2H, H-5 and
4.18. p-Tolyl 4-O-acetyl-2-O-levulinyl-1-thio-
rhamnopyranoside (16)
a-L-
OCHH), 3.46 (dd, 1H, J = 9.6, 7.3 Hz, H-4), 3.43–3.39 (m, 1H, OCHH),
2.90–2.40 (m, 8H, 2 ꢃ COCH2CH2CO), 2.22, 2.16, 2.13, 2.12, 2.11
(5s, each 3H, 5 ꢃ COCH3), 1.60–1.55 (m, 2H, OCH2CH2), 1.53, 1.32
(2s, each 3H, 2 ꢃ CH3), 1.26 (d, 3H, J = 5.9 Hz, 6-Me), 1.25 (br s,
18H, (CH2)9), 1.20 (d, 3H, J = 6.4 Hz, 60-Me), 1.19 (d, 3H, J = 6.4 Hz,
600-Me), 0.88 (t, 3H, J = 7.1 Hz, CH2CH3); 13C NMR (150 MHz, CDCl3)
d 206.6, 206.1, 172.1, 171.3, 170.4, 170.2, 170.1, 167.7, 132.4, 130.9,
128.8, 109.5, 98.7, 96.9, 95.9, 78.0, 77.5, 76.2, 74.4, 72.6, 71.8, 71.4,
70.6, 70.2, 68.6, 67.8, 67.1, 63.7, 38.0, 37.6, 31.9, 29.8–29.3, 28.4,
27.9, 27.8, 27.7, 26.4, 26.1, 22.7, 20.9, 20.8, 18.0, 17.4, 17.3, 14.1;
ESIMS: calcd for [M+Na]+ m/z 1009.5; found: 1009.5.
To a stirred solution of p-tolyl 4-O-acetyl-2-O-levulinyl-3-O-p-
methoxybenzyl-1-thio- -rhamnopyranoside (500 mg, 0.9 mmol)
a-L
in CH2Cl2 (30 mL) and H2O (2 mL), was added DDQ (321.1 mg,
1.4 mmol) at room temperature. The reaction mixture was stirred
until the reaction was completed indicated by TLC. The reaction
mixture was poured into saturated aqueous NaHCO3 solution
(20 mL) and extracted with CH2Cl2 (2 ꢃ 50 mL). The combined or-
ganic phase was washed with saturated aqueous NaHCO3
(2 ꢃ 50 mL) and brine (2 ꢃ 50 mL), dried over Na2SO4, and concen-
trated. The residue was purified by silica gel column chromatogra-
phy (4:1 petroleum ether–EtOAc) to give 16 (294.0 mg, 76%) as a
4.16. Dodecanyl 4-O-acetyl-2,3-O-isopropylidene-a-L-
rhamnopyranosyl-(1?3)-4-O-acetyl-2-O-levulinyl-
rhamnopyranosyl-(1?3)-4-O-acetyl-2-O-levulinyl-
a
-
L
L
-
-
syrup: Rf 0.45 (1:1 petroleum ether–EtOAc); ½a D20
ꢂ122.9 (c 0.05,
ꢄ
a-
CHCl3); 1H NMR (600 MHz, DMSO-d6) d 7.34 (d, 2H, J = 8.3 Hz,
PhH), 7.19 (d, 2H, J = 8.3 Hz, PhH), 5.49 (d, J = 5.5 Hz, 3-OH), 5.31
(d, 1H, J = 1.1 Hz, H-1), 5.15 (dd, 1H, J = 3.3, 1.1 Hz, H-2), 4.79 (t,
1H, J = 9.9 Hz, H-4), 4.12–4.09 (m, 1H, H-5), 3.84 (ddd, 1H, J = 9.3,
5.5, 3.3 Hz, H-3), 2.73–2.50 (m, 4H, COCH2CH2CO), 2.29 (s, 3H,
PhCH3), 2.10, 2.08 (s, each 3H, 2 ꢃ COCH3), 1.08 (d, 3H, J = 6.0 Hz,
6-Me); 13C NMR (150 MHz, DMSO-d6) d 207.2, 172.0, 171.2,
138.0, 132.3, 132.0, 129.9, 129.6, 86.0, 74.7, 74.2, 69.3, 67.3, 38.2,
29.7, 28.1, 21.1, 21.0, 17.3; ESIMS: calcd for [M+Na]+ m/z 433.1;
found: 433.1.
rhamnopyranosyl-(1?4)-2,3-O-isopropylidene-a-L-
rhamnopyranoside (14)
Compound 14 was prepared from donor 15 and acceptor 11 by
method A. Yields: 65%; Rf 0.63 (1:1 petroleum ether–EtOAc); ½a D20
ꢄ
ꢂ20.1 (c 0.17, CHCl3); 1H NMR (600 MHz, CDCl3) d 5.29 (dd, 1H,
J = 3.2, 1.3 Hz, H-20), 5.21 (s, 1H, H-10), 5.20 (s, 1H, H-100), 5.11
(s, 1H, H-1000), 4.94 (s, 1H, H-1), 4.93 (t, 1H, J = 9.9 Hz, H-400),
4.88 (t, 1H, J = 9.9 Hz, H-40), 4.81 (dd, 1H, J = 10.3, 8.3 Hz, H-4000),
4.75 (dd, 1H, J = 4.5, 2.6 Hz, H-200), 4.22 (dd, 1H, J = 8.3, 5.8 Hz,
H-3000), 4.16 (dd, 1H, J = 7.0, 5.8 Hz, H-3), 4.12 (dd, 1H, J = 9.7,
4.5 Hz, H-300), 4.07 (dd, 1H, J = 9.9, 3.2 Hz, H-30), 4.06 (dd, 1H,
J = 3.2, 1.9 Hz, H-2), 4.14 (d, 1H, J = 5.1 Hz, H-2000), 3.99–3.96 (m,
1 H, H-5000), 3.80–3.75 (m, 1 H, H-50), 3.73–3.69 (m, 1 H, H-5),
3.68–3.64 (m, 1H, OCHH), 3.53–3.48 (m, 1H, H-500), 3.45 (dd, 1H,
J = 9.6, 7.1 Hz, H-4), 3.42–3.38 (m, 1H, OCHH), 2.88–2.75, 2.64–
2.53, 2.50–2.45 (m, 8H, 2 ꢃ COCH2CH2CO), 2.19, 2.18, 2.13, 2.11,
2.10 (5s, each 3H, 5 ꢃ COCH3), 1.60–1.57 (m, 2H, OCH2CH2),
1.55, 1.51, 1.33, 1.32 (4s, each 3H, 2 ꢃ C(CH3)2), 1.30 (d, 3H,
J = 6.4 Hz, 6-Me), 1.26 (br s, 18H, (CH2)9), 1.20 (d, 3H, J = 6.4 Hz,
600-Me), 1.16 (d, 6H, J = 6.4 Hz, 60-Me and 6000-Me), 0.88 (t, 3H,
J = 6.9 Hz, CH2CH3); ESIMS: calcd for [M+Na]+ m/z 1195.6; found:
1195.7.
4.19. p-Tolyl 4-O-benzoyl-2-O-levulinyl-1-thio-a-L-
rhamnopyranoside (19)
Compound 21 (500 mg, 1.6 mmol) was dissolved in pyridine
(20 mL). BzCl (0.4 mL, 3.2 mmol) was added dropwise at 0 °C. The
solution was stirred for 2 h and then warmed to room temperature.
After the reaction was completed indicated by TLC, the mixture
was diluted with CH2Cl2 (100 mL), and washed consecutively with
water (50 mL), HCl (3 ꢃ 50 mL), saturated aqueous NaHCO3 solu-
tion (2 ꢃ 50 mL) and brine (50 mL). The organic layer was dried
over Na2SO4 and concentrated. Purification of the residue on a sil-
ica gel column (20:1 petroleum ether–EtOAc) gave 19 (587.6 mg,
88%) as a syrup: Rf 0.55 (15:1 petroleum ether–EtOAc); ½a D22
ꢄ
ꢂ202.4 (c 0.1, CHCl3); 1H NMR (600 MHz, CDCl3) d 8.13–7.15 (m,
9H, PhH), 5.75 (s, 1H, H-1), 5.20 (dd, 1H, J = 10.1, 7.3 Hz, H-4),
4.42–4.33 (m, 3H, H-2, H-3 and H-5), 2.34 (s, 3H, PhCH3), 1.63,
1.37 (s, each 3H, 2 ꢃ CH3), 1.19 (d, 3H, J = 6.4 Hz, 6-Me); 13C NMR
(CDCl3) d 171.7, 165.7, 133.7–128.4, 101.1, 84.1, 76.5, 75.6, 75.1,
65.7, 27.7, 26.5, 21.1, 16.9; ESIMS: calcd for [M+Na]+ m/z 437.1;
found: 437.2.
4.17. p-Tolyl 4-O-acetyl-2,3-O-isopropylidene-a-L-
rhamnopyranosyl-(1?3)-4-O-acetyl-2-O-levulinyl-1-thio-a-L-
rhamnopyranoside (15)
To
(46.1 mg, 0.12 mmol) and 4 Å molecular sieves in dry CH2Cl2
(5 mL) was added TMSOTf (2
a solution of compound 16 (40.5 mg, 0.10 mmol), 17
lL, 0.02 mmol) at ꢂ20 °C under ar-
gon. The reaction mixture was stirred under ꢂ20 °C, until TLC indi-
cated that the reaction was completed. The reaction was quenched
by the addition of Et3N and the mixture was concentrated. The res-
idue was purified by silica gel column chromatography (3:1 petro-
leum ether–EtOAc) to give 15 (48.7 mg, 77%) as a syrup: Rf 0.33
4.20. p-Tolyl 4-O-n-hexanoyl-2-O-levulinyl-1-thio-a-L-
rhamnopyranoside (20)
Compound 21 (516.9 mg, 1.7 mmol) was dissolved in pyridine
(20 mL). n-Hexanoyl chloride (0.4 mL, 2.5 mmol) was added drop-
wise at 0 °C. The solution was stirred for 2 h and then warmed to
room temperature. After the reaction was completed indicated
by TLC, the mixture was diluted with CH2Cl2 (100 mL), and then
washed consecutively with water (50 mL), HCl (3 ꢃ 50 mL), satu-
rated aqueous NaHCO3 solution (2 ꢃ 50 mL) and brine (50 mL).
The organic layer was dried over Na2SO4 and concentrated. Purifi-
cation of the residue on a silica gel column (20:1 petroleum ether–
EtOAc) gave 20 (460.6 mg, 68%) as a syrup: Rf 0.65 (10:1 petroleum
(2:1 petroleum ether–EtOAc); ½a D20
ꢄ
ꢂ62.5 (c 0.10, CHCl3); 1H
NMR (600 MHz, CDCl3) d 7.34 (d, 2H, J = 8.3 Hz, PhH), 7.12 (d, 2H,
J = 8.3 Hz, PhH), 5.36 (d, J = 1.7 Hz, H-2), 5.30 (s, 1H, H-1), 5.11 (s,
1H, H-10), 5.10 (t, 1H, J = 9.9 Hz, H-4), 4.82 (dd, 1H, J = 9.9, 8.2 Hz,
H-40), 4.32–4.27 (m, 1H, H-5), 4.21 (dd, 1H, J = 7.7, 5.5 Hz, H-30),
4.14 (dd, 1H, J = 9.9, 3.3 Hz, H-3), 4.04 (d, 1H, J = 5.5 Hz, H-20),
3.72–3.67 (m, 1H, H-50), 2.77–2.61 (m, 4H, COCH2CH2CO), 2.33 (s,
3H, PhCH3), 2.19, 2.12, 2.10 (s, each 3H, 3 ꢃ COCH3), 1.54, 1.33 (s,
each 3H, 2 ꢃ CH3), 1.22 (d, 3H, J = 6.0 Hz, 6-Me), 1.14 (d, 3H,
J = 6.0 Hz, 60-Me); 13C NMR (150 MHz, CDCl3) d 205.9, 171.7,
170.3, 170.0, 138.2, 132.3, 129.9, 129.3, 109.6, 99.4, 86.0, 76.0,
75.4, 74.3, 74.1, 73.3, 73.2, 67.7, 64.8, 37.8, 29.7, 28.1, 27.6, 26.4,
21.1, 20.9, 17.3, 16.7; ESIMS: calcd for [M+Na]+ m/z 661.2; found:
661.1.
ether–EtOAc); ½a D22
ꢄ
ꢂ174.5 (c 0.1, CHCl3); 1H NMR (600 MHz,
CDCl3) d 7.36 (d, 2H, J = 8.7 Hz, PhH), 7.13 (d, 2H, J = 7.8 Hz, PhH),
5.69 (s, 1H, H-1), 4.94 (dd, 1H, J = 10.1, 7.8 Hz, H-4), 4.35 (d, 1H,
J = 5.9 Hz, H-2), 4.22–4.18 (m, 2H, H-3 and H-5), 2.40–2.32 (m,
5H, COCH2 and PhCH3), 1.67–1.64 (m, 2H, COCH2CH2), 1.57, 1.35
(s, each 3H, 2 ꢃ CH3), 1.34–1.30 (m, 4H, 2 ꢃ CH2), 1.12 (d, 3H,

2134
N. Ding et al. / Carbohydrate Research 346 (2011) 2126–2135
J = 6.4 Hz, 6-Me); 0.90 (t, 3H, J = 6.8 Hz, Me); 13C NMR (150 MHz,
CDCl3) d 172.9, 138.0, 132.4, 129.9, 129.4, 110.0, 84.0, 76.4, 75.6,
74.3, 65.5, 34.3, 31.2, 27.7, 26.5, 24.6, 22.3, 21.1, 16.9, 13.9; ESIMS:
calcd for [M+Na]+ m/z 431.2; found: 431.2.
J = 1.5 Hz, H-10), 5.20 (dd, 1H, J = 3.3, 1.7 Hz, H-20), 5.07 (s, 1H, H-
100), 5.04 (t, 1H, J = 9.9 Hz, H-40), 4.94 (s, 1H, H-1), 4.81 (dd, 1H,
J = 10.2, 8.2 Hz, H-400), 4.21 (dd, 1H, J = 8.1, 5.5 Hz, H-300), 4.17 (dd,
1H, J = 7.3, 5.7 Hz, H-3), 4.08 (d, 1H, J = 5.7 Hz, H-2), 4.06 (dd, 1H,
J = 9.9, 3.3 Hz, H-30), 4.01 (d, 1H, J = 5.5 Hz, H-200), 3.80–3.66 (m,
4H, H-50, H-500, H-5 and OCHH), 3.46 (dd, 1H, J = 9.9, 7.3 Hz, H-4),
3.44–3.40 (m, 1H, OCHH), 2.78–2.68 (m, 4H, COCH2CH2CO), 2.35–
2.34 (m, 2H, CHHCO), 2.19, 2.09 (2s, each 3H, 2 ꢃ CH3CO), 1.64–
1.60 (m, 2H, CHHCH2CO), 1.58–1.56 (m, 2H, OCH2CHH), 1.53,
1.52, 1.32, 1.31 (4s, each 3H, 4 ꢃ CH3), 1.27 (d, 3H, J = 6.4 Hz, 6-
CH3), 1.26 (br s, 22H, (CH2)2 and (CH2)9), 1.19 (d, 3H, J = 6.6 Hz,
600-CH3), 1.12 (d, 3H, J = 6.3 Hz, 60-CH3), 0.89 (t, 3H, J = 7.1 Hz,
CH3); 0.88 (t, 3H, J = 7.2 Hz, CH3); 13C NMR (125 MHz, CDCl3) d
205.8, 173.1, 171.6, 170.0, 133.9, 130.0, 109.5, 109.4, 99.9, 99.4,
96.8, 95.9, 78.0, 77.5, 74.1, 73.9, 73.2, 71.8, 67.8, 66.9, 64.7, 63.7,
37.9, 34.3, 31.9, 31.2, 29.8–29.3, 28.6, 28.2, 27.9, 27.6, 26.4, 26.3,
26.1, 24.5, 22.7, 22.3, 20.9, 18.0, 17.4, 16.7, 14.1, 13.9; ESIMS: calcd
for [M+Na]+ m/z 965.5; found: 965.7.
4.21. Dodecanyl 4-O-acetyl-2,3-O-isopropylidene-
a-L-
rhamnopyranosyl-(1?3)-4-O-acetyl-2-O-levulinyl-
a-L-
rhamnopyranosyl-(1?4)-2,3-O-isopropylidene-a-L-
rhamnopyranoside (22)
Compound 22 was prepared from donor 18 and acceptor 11 by
method A. Yeild: 99%; Rf 0.60 (1:1 petroleum ether–EtOAc); ½a D20
ꢄ
ꢂ23.6 (c 0.10, CHCl3); 1H NMR (600 MHz, CDCl3) d 5.25 (d, 1H,
J = 0.9 Hz, H-10), 5.20 (dd, 1H, J = 3.2, 1.4 Hz, H-20), 5.08 (s, 1H, H-
100), 5.04 (t, 1H, J = 9.8 Hz, H-40), 4.95 (s, 1H, H-1), 4.81 (dd, 1H,
J = 10.1, 8.3 Hz, H-400), 4.23 (dd, 1H, J = 7.8, 5.5 Hz, H-300), 4.17 (dd,
1H, J = 7.3, 5.5 Hz, H-3), 4.09 (d, 1H, J = 5.5 Hz, H-2), 4.06 (dd, 1H,
J = 9.7, 3.2 Hz, H-30), 4.02 (d, 1H, J = 5.5 Hz, H-200), 3.82–3.78 (m,
1H, H-50), 3.76–3.72 (m, 1H, H-500), 3.71–3.65 (m, 2H, H-5 and
OCHH), 3.41 (dd, 1H, J = 9.6, 7.3 Hz, H-4), 3.43–3.39 (m, 1H, OCHH),
2.79–2.77 (m, 4H, CO(CH2)2CO), 2.20, 2.11, 2.10 (3s, each 3H,
3 ꢃ COCH3), 1.60–1.56 (m, 2H, OCH2CH2), 1.54, 1.52, 1.32, 1.31
(4s, each 3H, 4 ꢃ CH3), 1.28 (d, 3H, J = 5.9 Hz, 6-Me), 1.25 (br s,
18H, (CH2)9), 1.20 (d, 3H, J = 6.4 Hz, 60-Me), 1.13 (d, 3H, J = 6.4 Hz,
600-Me), 0.88 (t, 3H, J = 7.1 Hz, CH3); 13C NMR (150 MHz, CDCl3) d
205.9, 171.6, 170.4, 170.0, 109.5, 109.4, 99.4, 96.9, 96.0, 78.0,
77.6, 76.3, 76.1, 75.5, 74.3, 74.1, 73.2, 71.8, 67.8, 66.9, 64.7, 63.7,
37.9, 31.9, 29.8–29.3, 28.2, 27.9, 27.6, 26.4, 26.1, 22.7, 21.1, 20.9,
18.1, 17.4, 16.7, 14.1; ESIMS: calcd for [M+Na]+ m/z 909.5; found:
909.5.
4.24. Dodecanyl 4-O-acetyl-2,3-O-isopropylidene-a-L-
rhamnopyranosyl-(1?4)-2,3-O-isopropylidene-a-L-
rhamnopyranoside (26)
Compound 26 was prepared from donor 18 and acceptor 25 by
method A. Yield: 74%; Rf 0.63 (5:1 petroleum ether–EtOAc); ½a D20
ꢄ
ꢂ27.3 (c 0.19, CHCl3); 1H NMR (600 MHz, CDCl3) d 5.64 (s, 1H, H-
10), 4.95 (s, 1H, H-1), 4.88 (t, 1H, (dd, 1H, J = 10.1, 7.8 Hz, H-40),
4.21 (dd, 1H, J = 7.3, 5.9 Hz, H-3), 4.17 (d, 1H, J = 5.5 Hz, H-2), 4.12
(dd, 1H, J = 7.7, 5.5 Hz, H-30), 4.11 (d, 1H, J = 5.9 Hz, H-20), 3.76–
3.71 (m, 1H, H-50), 3.69–3.64 (m, 2H, H-5 and OCHH), 3.57 (dd,
1H, J = 10.1, 7.3 Hz, H-4), 3.44–3.40 (m, 1H, OCHH), 2.10 (s, 3H,
COCH3), 1.57, 1.55, 1.35, 1.33 (4s, each 3H, 4 ꢃ CH3), 1.26 (br s,
20H, (CH2)10), 1.25 (d, 3H, J = 6.0 Hz, 6-Me), 1.16 (d, 3H, J = 6.0 Hz,
60-Me), 0.88 (t, 3H, J = 7.1 Hz, CH2CH3); 13C NMR (150 MHz, CDCl3)
d 170.1, 109.6, 109.4, 96.8, 95.5, 78.5, 76.2, 75.6, 74.3, 67.7, 64.3,
63.7, 31.9, 29.6–29.3, 26.4, 26.3, 26.1, 22.7, 21.0, 17.9, 16.7, 14.1;
ESIMS: calcd for [M+Na]+ m/z 623.4; found: 623.4.
4.22. Dodecanyl 4-O-benzoyl-2,3-O-isopropylidene-
rhamnopyranosyl-(1?3)-4-O-acetyl-2-O-levulinyl-
a
-
L
-
a
-
L
-
rhamnopyranosyl-(1?4)-2,3-O-isopropylidene-a-L-
rhamnopyranoside (23)
Compound 23 was prepared from donor 19 and acceptor 11 by
method A. Yield: 55%; Rf 0.53 (2:1 petroleum ether–EtOAc); ½a D20
ꢄ
ꢂ43.6 (c 0.10, CHCl3); 1H NMR (600 MHz, CDCl3) d 8.10 (d, 2H,
J = 8.4 Hz, Ph), 7.56 (t, 1H, J = 7.3 Hz, Ph), 7.43 (t, 1H, J = 7.7 Hz,
Ph), 5.26 (d, 1H, J = 1.4 Hz, H-10), 5.25 (dd, 1H, J = 3.3, 1.4 Hz, H-
20), 5.13 (s, 1H, H-100), 5.08 (t, 1H, J = 9.9 Hz, H-40), 5.06 (dd, 1H,
J = 10.1, 8.0 Hz, H-400), 4.94 (s, 1H, H-1), 4.40 (dd, 1H, J = 7.7,
5.5 Hz, H-300), 4.18 (dd, 1H, J = 7.3, 5.5 Hz, H-3), 4.09 (dd, 1H,
J = 7.7, 3.3 Hz, H-30), 4.08 (d, 2H, J = 5.5 Hz, H-2 and H-200), 3.93–
3.88 (m, 1H, H-50), 3.84–3.79 (m, 1H, H-500), 3.73–3.65 (m, 2H, H-
5 and OCHH), 3.47 (dd, 1H, J = 9.9, 7.3 Hz, H-4), 3.43–3.39 (m, 1H,
OCHH), 2.80–2.67 (m, 4H, CO(CH2)2CO), 2.20, 2.12 (2s, each 3H,
2 ꢃ COCH3), 1.59, 1.52, 1.33, 1.31 (4s, each 3H, 4 ꢃ CH3), 1.59–
1.55 (m, 2H, OCH2CH2), 1.29 (d, 3H, J = 6.2 Hz, 6-CH3), 1.26 (br s,
18H, (CH2)9), 1.21 (d, 3H, J = 6.2 Hz, 600-CH3), 1.18 (d, 3H,
J = 6.2 Hz, 60-CH3), 0.88 (t, 3H, J = 7.1 Hz, CH3); 13C NMR
(150 MHz, CDCl3) d 205.7, 171.6, 170.0, 165.9, 133.1, 129.9,
128.3, 109.6, 109.4, 99.6, 96.8, 95.9, 77.9, 77.5, 76.2, 76.1, 75.6,
74.8, 74.3, 73.1, 71.8, 67.8, 66.9, 64.9, 63.7, 37.8, 31.9, 29.8–29.3,
28.1, 27.9, 27.7, 26.4, 26.3, 26.1, 22.7, 20.9, 18.0, 17.4, 16.8, 14.1;
ESIMS: calcd for [M+Na]+ m/z 971.5; found: 971.6.
4.25. Dodecanyl 3,4-di-O-acetyl-2-O-levulinyl-a-L-
rhamnopyranosyl-(1?4)-2,3-O-isopropylidene-a-L-
rhamnopyranoside (27)
A suspension of 11 (150.0 mg, 0.23 mmol) in dry CH2Cl2 (10 mL)
were placed in an ice bath with continuous stirring. To this cold
suspension were added Ac2O (64.5
lL, 0.68 mol) and Et3N
(94.1 L, 0.68 mol) dropwise over a period of 30 min. The reaction
l
mixture was stirred for another 30 min. DMAP (2.8 mg, 0.02 mmol)
was added in one portion. The reaction mixture was stirred for 12 h
at room temperature, and then reaction was quenched by the addi-
tion of CH3OH (30 mL) and concentrated. The residue was diluted
with CH2Cl2 (50 mL), washed with saturated aqueous NaHCO3
(3 ꢃ 20 mL), brine (2 ꢃ 20 mL), dried over Na2SO4, filtered and con-
centrated under diminished pressure.
The above crude was treated with NH2NH2ꢁHOAc (211.8 mg,
2.3 mmol) as described in general procedure
B to give 27
(114.2 mg, 83% for two steps) as a syrup. Rf 0.48 (2:1 petroleum
ether–EtOAc); ½a D20
ꢄ
ꢂ54.9 (c 0.12, CHCl3); 1H NMR (600 MHz,
CDCl3) d 5.41 (d, 1H, J = 1.7 Hz, H-10), 5.17 (dd, 1H, J = 9.9, 3.3 Hz,
H-30), 5.16 (d, 1H, J = 3.3 Hz, H-20), 5.11 (t, 1H, J = 9.9 Hz, H-40),
4.95 (s, 1H, H-1), 4.18 (dd, 1H, J = 7.1, 5.5 Hz, H-3), 4.09 (d, 1H,
J = 5.5 Hz, H-2), 4.07 (br s, 1H, 20-OH), 3.91–3.87 (m, 1H, H-50),
3.72–3.68 (m, 1H, H-5), 3.68–3.65 (m, 1H, OCHH), 3.52 (dd, 1H,
J = 9.9, 7.1 Hz, H-4), 3.43–3.40 (m, 1H, OCHH), 2.09, 2.05 (2s, each
3H, 2 ꢃ COCH3), 1.60–1.56 (m, 2H, OCH2CH2), 1.53, 1.33 (2s, each
3H, 2 ꢃ CH3), 1.30 (d, 3H, J = 6.4 Hz, 6-Me), 1.26 (br s, 18H,
9 ꢃ CH2), 1.21 (d, 3H, J = 6.4 Hz, 60-Me), 0.88 (t, 3H, J = 6.9 Hz,
4.23. Dodecanyl 4-O-n-hexanoyl-2,3-O-isopropylidene-
a-L-
rhamnopyranosyl-(1?3)-4-O-acetyl-2-O-levulinyl-
a-L-
rhamnopyranosyl-(1?4)-2,3-O-isopropylidene-a-L-
rhamnopyranoside (24)
Compound 24 was prepared from donor 20 and acceptor 11 by
method A. Yield: 49%; Rf 0.50 (2:1 petroleum ether–EtOAc); ½a D20
ꢄ
ꢂ21.8 (c 0.10, CHCl3); 1H NMR (500 MHz, CDCl3,) d 5.24 (d, 1H,

N. Ding et al. / Carbohydrate Research 346 (2011) 2126–2135
2135
CH2CH3); 13C NMR (150 MHz, CDCl3) d 170.1 170.0, 109.4, 97.9,
96.8, 78.4, 77.9, 76.2, 71.5, 71.3, 69.8, 67.8, 66.6, 63.7, 31.9, 29.6–
29.3, 27.9, 26.3, 26.1, 22.7, 20.9, 20.8, 18.1, 17.4, 14.1; ESIMS: calcd
for [M+Na]+ m/z 625.4; found: 625.4.
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Acknowledgments
This work was supported by National Natural Science Founda-
tion of China (21002014), Research Fund for the Doctoral Program
of Higher Education of China (RFDP, 20100071120051), the Funda-
mental Research Funds for the Central Universities (10FX061) and
the Startup Foundation for Young Teachers, School of Pharmacy,
Fudan University.
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Supplementary data
Supplementary data associated with this article can be found, in
the online version, at doi:10.1016/j.carres.2011.07.028.
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