Design, synthesis and evaluation of a novel class of glucosamine mimetic peptides containing 1,3-dioxane

Article abstract of DOI:10.1016/j.ejmech.2015.01.062

A number of novel 2-(N-(2-(5,5-dimethyl-1,3-dioxane-2-yl)ethyl)aminoacyl)amino-2-deoxy- d-glucopyranoside were synthesized from a readily available starting material, glucosamine, 2,2-dimethyl-1,3-propanediol and 1,1,3,3-tetramethoxypropane, and evaluated

Full text of DOI:10.1016/j.ejmech.2015.01.062

Accepted Manuscript
Design, synthesis and evaluation of a novel class of glucosamine mimetic peptides
containing 1,3-dioxane
Li Zeng, Guichao Xu, Pengchao Gao, Meng Zhang, Hong Li, Jianwei Zhang
PII:
S0223-5234(15)00083-5
10.1016/j.ejmech.2015.01.062
EJMECH 7679
DOI:
Reference:
To appear in: European Journal of Medicinal Chemistry
Received Date: 26 February 2014
Revised Date: 29 January 2015
Accepted Date: 31 January 2015
Please cite this article as: L. Zeng, G. Xu, P. Gao, M. Zhang, H. Li, J. Zhang, Design, synthesis and
evaluation of a novel class of glucosamine mimetic peptides containing 1,3-dioxane, European Journal
of Medicinal Chemistry (2015), doi: 10.1016/j.ejmech.2015.01.062.
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ACCEPTED MANUSCRIPT
Graphic Abstract
Design, synthesis and evaluation of a novel class of glucosamine mimetic peptides
containing 1,3-dioxane
a
b
a
a
a
a
Li Zeng , Pengchao Gao , Meng Zhang , Guichao Xu , Hong Li , and Jianwei Zhang*
Some novel glucosamine mimetic peptides containing 1,3-dioxane were obtained and evaluated for
their anti-inflammatory effect.
OH
OR1
O
NH
OH
O
HO
HO
OH
R O
1
O
R O
1
R
2
HO
HO
OH
R2
NH
OR1
O
N
NH2
BocHN
H
O
O
O
Inhibition ratio (%) : 64.3
Inhibition ratio (%) : 80.3- 88.7
HN
CH
2
Wherein R
1
= Ac or Bn; R
2
= CH(CH
3
)CH
2
CH
3
, CH
2
C
6
H
5
, CH(CH
3
)
2
, CH
3
,
or
CH CH(CH ) .
2
3 2

ACCEPTED MANUSCRIPT
Design, synthesis and evaluation of a novel class of glucosamine mimetic peptides
containing 1,3-dioxane
a
a
b
a
a
a
Li Zeng , Guichao Xu , Pengchao Gao , Meng Zhang , Hong Li , and Jianwei Zhang*
a
College of Pharmaceutical Sciences, Capital Medical University, Beijing 100069, PRC
b
School of Pharmacy Institute of Peking University, Beijing 100191, PRC
*Corresponding author. Tel.: 86-10-8391-1522; fax: 86-10-8391-1533;
E-mail: jwzhang2006@163.com
ABSTRACT
number of novel 2-(N-(2-(5,5-dimethyl-1,3-dioxane-2-yl)ethyl)aminoacyl)amino-2-deoxy-
A
D-glucopyranoside were synthesized from a readily available starting material, glucosamine,
2,2-dimethyl-1,3-propanediol and 1,1,3,3-tetramethoxypropane, and evaluated for their
anti-inflammatory activity. Our results showed that all of the compounds tested exhibited a significant
inhibition of xylene-induced inflammation in mice.
Keywords: Amino sugar; 1,3-Dioxane; Glucosamine; Inflammation
1

ACCEPTED MANUSCRIPT
1. Introduction
Inflammatory diseases are widely prevalent throughout the world and affect many people’s lifes.
Inflammation is a normal protective response of mammalian tissues to a variety of hostile agents
including infectious organisms, noxious chemicals, physical injury or tumor growth leading to local
accumulation of plasmic fluid and blood cells. Although inflammation is a defense mechanism, the
complex events and mediators involved in the inflammatory response can induce and aggravate many
disorders. Inflammation is involved in various clinical conditions such as arthritis, cancer and vascular
diseases.
Drugs used for the treatment of acute and chronic inflammatory disorders are usually directed at the
inflammatory processes. Hence, the employment of anti-inflammatory agents may be helpful in the
treatment of those conditions associated with inflammatory reactions. Many non-steroidal
anti-inflammatory agents on the market have been of immense help in the management of various
inflammatory conditions like rheumatism, arthritis and breast pain. However, there is always a need for
the development of better anti-inflammatory agents.
The dioxane moiety is a common structural motif in a number of bioactive molecules. In 1966, the
1,3-dioxolane derivative dexoxadrol was synthesized and pharmacologically evaluated as a local
anesthetic and general anesthetic drug [1]. Recently, 1,3-dioxanes have been evaluated as effective
modulators for multi-drug resistance [2] and reported with anti-inflammatory activities [3]. Some
2,5-multisubstituted-1,3-dioxane derivatives have been identified to have significant biological
activities or can be converted into active compounds [4-5]. Though promising anti-inflammatory agents
substituted 1,3-dioxanes were prepared in some laboratories and the importance for both 2- and
5-position substitutions was explored [6-9], the diversity of substitutions at positions 2, 5 was still poor.
Glucosamine (GlcN)
,
an amino monosaccharide, is the most common amino sugar and is generally
2

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found as an N-acetylated and
β-linked glycoside. It is found in connective tissues and gastrointestinal
mucosal membranes. However, the ability to synthesize GlcN in the body declines with age. This, in
turn, incapacitates the generation of proteoglycan, which is known to result in senile osteoarthritis (OA)
[
10-11]. Therefore, GlcN salts (sulfate and chloride) are thought to be beneficial in promoting the
repair of damaged cartilage. Since the first publication of W. Bohne in 1969 showing that GlcN can be
used to relieve the symptoms of OA, GlcN has received a great deal of attention from the public as a
potential treatment for OA [12-13]. Furthermore, GlcN possesses antioxidant activities due to its
pronounced reducing power, superoxide/hydroxyl-radical scavenging ability. It has been reported that
GlcN possesses a unique anti-inflammatory activities and inhibits IL-1β and TNF-α-induced NO
production in normal human articular chondrocytes [14]. It is also beneficial for inflammatory bowel
diseases [15].
One of the successful and effective approaches in the search for new bioactive agents is to synthesize
novel compounds by simple chemical modifications of lead compounds. In view of the
pharmacological importance of glucosamine as well as 1,3-dioxolane it has been considerably
worthwhile to prepare some new chemical entities containing glucosamine and 1,3-dioxolane moieties.
All these observation encouraged us to explore the synthesis of glucosamine containing 1,3-dioxolane
moieties and examine their activities as anti-inflammatory agents. Amide bond is stable in buffer
solution at pH 7.4 and in culture medium. Amide structure is found in various natural products,
pharmaceuticals, and polymers. Amides may be prepared by coupling reactions between carboxylic
acids and amines [16-18]. The synthetic design used for preparation of glycosyl amides was based
upon a number of reasons: (1) GlcN possesses some biological activity; (2) N-acetylglucosamine has
several potential advantages over GlcN as a potential therapeutic anti-inflammatory agent [19]. In
3

ACCEPTED MANUSCRIPT
addition, amino acid conjugates might target the gastrointestinal transporters involved in the absorption
of amino acids and small peptides resulting in improved oral bioavailability [20]. Moreover, amino
acids are attractive because they possess structurally diverse side chains. The various side chains of
different amino acids allow the addition of amino acids to 1,3-dioxane to manipulate the
pharmacokinetics profiles of the compounds. Furthermore, various amino acids can be introduced to
enhance solubility. Therefore, in order to search for better anti-inflammatory agents, a novel class of
glucosamine mimetic peptides containing 1,3 dioxane were designed and synthesized and evaluated for
their anti-inflammatory activity.
2. Chemistry
The synthesis of the corresponding 2-(2,2-dimethoxylethyl)-5,5-dimethyl-1,3-dioxane (Compound 3)
has been achieved, as shown in Scheme 1, starting from the readily available
2,2-Dimethyl-1,3-propanediol (Compound 1) with 1,1,3,3-tetramethoxypropane (Compound 2) under
acidic conditions in 65% yield as a major product [21]. The minor product, assigned as
bis(5,5-dimethyl-1,3-dioxane-2-yl)-methane (Compound 3’) was obtained in 20% yield. Then the
reaction of Compound 3 with 2,3-dichloro-5,6-dicyano-p-benzoquinone in aqueous acetonitrile
afforded 3-(5,5-dimethyl-1,3-dioxane-2-yl)-propanal (Compound 4) in 51% yield.
The synthetic routes for the preparation of glucosamine mimetic peptides containing 1,3 dioxane
from glucosamine (GlcN) salt (chloride) 1 as starting material were presented in Schemes 2 and 3.
Acylation of GlcN chloride with (Boc)
2
O resulted in N-Boc-glucosamine (Compound 6). The free OH
groups of N-Boc-glucosamine
6
were benzylated with NaH and BnBr to give
1,3,4,6-tetra-O-benzyl-2-(tert-butyloxycarbonylamino)-2-deoxy-D-glucopyranoside (Compound 7)
[
22]. Subsequently, Boc groups of 7 were removed by subjecting 7 to trifluoroacetic acid in
4

ACCEPTED MANUSCRIPT
dichloromethane to give N-terminal free intermediates (Compound 8). 8 was further reacted with
Boc-protected amino acids by the DCC/HOBt/N-methylmorpholine (NMM) procedure to give
1,3,4,6-Tetra-O-benzyl-2-(N-Boc-aminoacylamino)-2-deoxy-α-D-glucopyranoside (Compounds 9a-f).
1
The H NMR spectra of 9a–f showed signals for their anomeric protons as doublets with coupling
constants of 3.6 Hz. In all cases, a noteworthy point is that sole the α-anomers are the products, which
can be attributed to the anomeric effect. Subsequently, removal of the Boc group with hydrogen
chloride in ethyl acetate led to a set of amine 10a-f and subsequent coupling with the Compound 4
gave 2-(N-(2-(5,5-dimethyl-1,3-dioxane-2-yl)ethyl)aminoacyl)amino-1,3,4,6-tetra-O-benzyl-2-deoxy-
1
α-D-glucopyranoside (Compounds 11a-f) (chemical yields, 33–54%). HNMR spectra indicated that
11a-f
were
α-anomers.
Effort
was
made
with
the
aim
of
preparing
2-(N-(2-(5,5-Dimethyl-1,3-dioxane-2-yl)ethyl)aminoacyl)amino-2-deoxy-D-glucopyranoside
(Compounds 16a-f) through removal of the benzyl group from Compounds 11a-f by palladium
catalyzed hydrogenolysis. However, the attempt was unsuccessful. Another synthetic strategy was
developed to remedy the failure of the previously adopted approach as shown in Scheme 3. GlcN
chloride
was
acetylated
with
acetic
anhydride
in
sulfuric
acid
to
give
2-amino-1,3,4,6-tetra-O-acetyl-2-deoxy-β-D-glucosamine (Compound 12). 12 was further reacted with
Boc-protected amino acids by the DCC/HOBt/N-methylmorpholine (NMM) procedure to afford
1,3,4,6-Tetra-O-acetyl -2-(N-Boc-aminoacylamino)-2-deoxy-α-D-glucopyranoside (Compounds 13a-f)
as single α-anomers (chemical yields, 31–56%). Subsequently, removal of the Boc group with
hydrogen chloride in ethyl acetate led to a set of amine 14a-f and subsequent coupling with the
Compound
4
in
the
presence
of
NaCNBH3
yielded
2-(N-(2-(5,5-dimethyl-1,3-dioxane-2-yl)ethyl)aminoacyl)amino-1,3,4,6-tetra-O-acetyl-2-deoxy-α-D-
5

ACCEPTED MANUSCRIPT
1
glucopyranoside (Compounds 15a-f) (chemical yields, 44–79%). The H NMR spectra of 15a–f
1
showed signals for their anomeric protons as doublets with coupling constants of 3.6 Hz. HNMR
spectra indicated that 15a-f were α-anomers. Finally, Compounds 15a-f was deacetylated with sodium
methoxide in methanol to give Compounds 16a-f in 39–51% yield as a mixture of anomers. The
structures of glucosamine mimetic peptides containing 1,3 dioxane are shown in Table 1. The
1
13
structures of all new compounds were unambiguously characterized with H NMR, C NMR, mass
spectrometry and high-resolution mass spectrometry and are in very good agreement with their
analytical and spectroscopic data (see Experimental part).
3. Pharmacology
3.1. Anti-inflammatory activity of glucosamine mimetic peptides containing 1,3 dioxane
Compounds 5, 11a-f, 15a-f and 16a-f were screened for their anti-inflammatory activity by using a
xylene-induced ear edema model assay. [21]. The compounds 16a-f used in the anti-inflammatory
activity are a mixture of anomers. Mice administered orally by gavage with 0.5% carboxymethyl
cellulose (CMC) suspension were used as negative control, and mice administered orally with Aspirin
(at a dosage of 100 mg/kg) in CMC were used as positive control. The compounds tested were
prepared as suspensions in 0.5% CMC at the concentration of 1 mM and were administered orally to
the animals at a dosage of 10 µmol/kg 30 min before xylene was applied to both the anterior and
posterior surfaces of the right ear. The left ear was considered as control. The extent of ear edema was
evaluated by the weight difference between the right and the left ear biopsies of the same animal. The
anti-inflammatory effect was defined by inhibition ratio (%) as:
Inhibition ratio % = (1- A/B) x 100%
A: The increase in weight caused by xylene
6

ACCEPTED MANUSCRIPT
B: The weight of the untreated left ear section
The percentage of inhibition is used as an indication of anti-inflammatory activity. The
anti-inflammatory activity of these derivatives is summarized in Table 2. The results showed that all of
the compounds tested exhibited a significant inhibitory activity against xylene-induced ear edema in
mice in comparison with the negative control group. The tested compounds showed inhibition ratio
ranging from 70.6% to 90.3% (P <0.01). It was found that most of tested compounds exhibited
anti-inflammatory effect similar to or better than the positive control, aspirin. To understand the
contribution of the 1, 3-dioxane to the anti-inflammatory activity observed, glucosamine GlcN
(Compound 5) was used as a reference compound. Comparison of the inhibition ratio values
(70.6-90.3%) of tested compounds with that of GlcN (64.3%) showed that the presence of 1,3-dioxane
increased the activity, suggesting that the 1,3-dioxane structure had a positive contribution to the
activity. This research provided useful information for the further design of novel potent
anti-inflammatory agents.
3.2. Effect of dose on anti-inflammatory activity
16a was selected to further explore the effect of dose on the anti-inflammatory activity. As shown in
Table 3, at 0.1, 1, and 10 µmol/kg, 16a exhibited inhibition ratio of 44.3, 70.8 and 88.7%, respectively.
4. Conclusion
In summary, a novel class of glucosamine mimetic peptides containing 1,3 dioxane were designed,
synthesized and evaluated for their anti-inflammatory effect. 1,3-Dioxane structure had a positive
contribution to the activity. It was found that most of tested compounds exhibited anti-inflammatory
effect similar to or better than the positive control, aspirin.
5. Experimental
7

ACCEPTED MANUSCRIPT
5
5
.1. Chemistry
.1.1. General methods
Unless otherwise stated, all reactions were under a nitrogen atmosphere (1 bar). All reagents used
were purchased from Sigma Chemical Co (USA). Optical rotations were determined with a
Schmidt+Haensch Polartromic D instrument (Germany). IR spectra were recorded with an Avatar 330,
1
13
Nicolet, USA spectrometer. H and C NMR spectra were recorded at 300MHz on a VXR-300
instrument or at 500MHz on a Bruker Am-500 instrument in CDCl
3
or in DMSO-d6 with
tetramethylsilane as internal standard and chemical shifts are expressed in ppm (δ). Chromatography
was carried out using Qingdao silica gel H (Qingdao of China). The purity of the intermediates and the
products was confirmed by TLC (Merck silica gel plates of type 60 F254, 0.25 mm layer thickness,
Germany) and HPLC (Waters, C18 column 4.6×150 mm, USA). Mass spectra (MS) were acquired on a
Quattro Micro ZQ2000, Waters, USA instrument and m/z values are reported. High-resolution mass
spectra were recorded with micrOTOF-Q mass spectrometer.
5.1.2. 1,3,4,6-Tetra-O-benzyl-2-(N-Boc-isoleucinylamino)-2-deoxy-α-D-glucopyranoside
HOBt (80.0 mg, 0.593 mmol) and DCC (124 mg, 0.602 mmol) were added to a solution of
Boc-L-Ile-OH (127 mg, 0.550 mmol) in anhydrous THF (10 mL) at 0°C. The mixture was stirred at
0
°C for 30 min. Compound 8 (270 mg, 0.500 mmol) in anhydrous THF (10 mL) was added and pH
was adjusted to 9 with N-methylmorpholine. The mixture obtained was kept at 0°C for 1 h followed by
at room temperature for 15 h. DCU formed was removed by filtration. The filtrate was subject to
evaporation under reduced pressure and the residue was dissolved in EtOAc (50 mL). The mixture
3 4
obtained was washed successively with saturated NaHCO , 5% KHSO and saturated NaCl, and the
2 4
organic phase was separated and dried over Na SO . Following filtration and evaporation under
8

ACCEPTED MANUSCRIPT
reduced pressure, purification of the residue by recrystallization in petroleum ether-dichloromethane
2
5
provided the title product, Compound 9a (223 mg, 0.297 mmol, 59%). [α]
D
3
+36.9 (c 0.1, CHCl );
-1
1
IR (cm , KBr, neat): 3315, 1683, 1654; HNMR (300 MHz, CDCl ): δ 7.38 ~ 7.27 (18H, m, Ar-H),
3
7.14 ~ 7.12 (2H, m, Ar-H), 6.16 (1H, d, J = 9.6 Hz, N-H), 4.94 (1H, d, J = 3.6 Hz, H-1), 4.82 ~ 4.50
2
(9H, m, H-2, CH ), 4.36 (1H, m, CH), 3.95 ~ 3.67 (5H, m, H-3, H-4, H-5, H-6, H-6’), 1.97 ~ 1.87 (2H,
3 3
m, CH, N-H), 1.45 (9H, s, CH ), 1.39 ~ 1.32 (m, 1H, CH), 0.86 (3H, d, J = 6.9 Hz, CH ), 0.78 (3H, t, J
13
=
3 3
7.5 Hz, CH ); CNMR (75 MHz, CDCl ): δ 171.4, 155.7, 138.3, 138.1, 138.0, 137.2, 128.6, 128.4,
1
3
28.3, 128.1, 128.0, 127.8, 127.6, 127.4, 97.1, 80.5, 78.2, 75.0, 74.7, 73.5, 71.2, 69.8, 68.6, 52.9, 36.8,
40 3
3.9, 28.3, 25.6, 24.9, 24.3, 15.7, 11.3; ESIMS m/z 753.4 (M+1); HRMS calcd for: (C25H N O12 + 1),
m/z (753.4109); found, m/z (753.3951).
5.1.3. 1,3,4,6-Tetra-O-benzyl-2-(N-Boc-phenylalanylamino)-2-deoxy-α-D-glucopyranoside
HOBt (80.0 mg, 0.593 mmol) and DCC (124 mg, 0.602 mmol) were added to a solution of
Boc-L-Phe-OH (146 mg, 0.550 mmol) in anhydrous THF (10 mL) at 0℃. The reaction mixture was
stirred at 0℃ for 30 min. Compound 8 (270 mg, 0.500 mmol) in anhydrous THF (10 mL) was added
and pH was adjusted to 9 with N-methylmorpholine. The reaction mixture obtained was kept at 0℃ for
1
h followed by at room temperature for 15 h. DCU formed was removed by filtration. The filtrate was
subject to evaporation under reduced pressure and the residue was dissolved in EtOAc (50 mL). The
solution was washed successively with saturated NaHCO , 5% KHSO and saturated NaCl, and the
3
4
2 4
organic phase was separated and dried over Na SO . Following filtration and evaporation under
reduced pressure, purification of the residue by recrystallization in petroleum ether-dichloromethane
2
5
afforded the title product, Compound 9b (130 mg, 0.165 mmol, 33%). [α]
+51.4 (c 0.1, CHCl );
3
D
-
1
1
3
IR (cm , KBr, neat): 3323, 1687, 1654; HNMR (500 MHz, CDCl ): δ7.38 ~ 7.14 (25H, m, Ar-H), 6.26
9

ACCEPTED MANUSCRIPT
2 1
(1H, d, J = 9.3 Hz, N-H ), 4.94 (1H, d, J = 3.6 Hz, H-1), 4.82 ~ 4.35 (10H, m, CH ), 4.36 (1H, dt, J =
2
3.3 Hz, J = 9.3 Hz, CH), 3.95 ~ 3.67 (4H, m, H-2, H-3, H-4, H-5), 3.04 (2H, m, H-6, H-6’), 1.38 (9H,
1
3
s, CH ); CNMR (125 MHz, CDCl ): δ171.0, 155.3, 138.4, 138.1, 137.1, 136.6, 129.3, 128.6, 128.5,
3
3
1
7
28.4, 128.3, 128.2, 128.1, 128.0, 127.8, 127.8, 127.7, 127.6, 127.0, 97.3, 80.9, 80.2, 78.0, 75.1, 75.0,
3.5, 71.2, 69.8, 68.6, 55.7, 52.9, 49.2, 37.8, 33.9, 28.2, 25.6, 25.0; ESIMS m/z 787 (M+1); HRMS
40 3
calcd for: (C25H N O12 + 1), m/z (787.3953); found, m/z (787.3898).
5.1.4. 1,3,4,6-Tetra-O-benzyl-2-(N-Boc-valinylamino)-2-deoxy-α-D-glucopyranoside
HOBt (80.0 mg, 0.593 mmol) and DCC (124 mg, 0.602 mmol) were added to a solution of
Boc-L-Val-OH (119 mg, 0.550 mmol) in anhydrous THF (10 mL) at 0℃. The mixture was stirred at
0
℃ for 30 min. Compound 8 (270 mg, 0.500 mmol) in anhydrous THF (10 mL) was then added and
pH was adjusted to 9 with N-methylmorpholine. The reaction mixture obtained was kept at 0℃ for 1 h
followed by at room temperature for 15 h. DCU formed was removed by filtration. The filtrate was
subject to evaporation under reduced pressure and the residue was dissolved in EtOAc (50 mL). The
3 4
solution was washed successively with saturated NaHCO , 5% KHSO and saturated NaCl, and the
2 4
organic phase was separated and dried over Na SO . Following filtration and evaporation under
reduced pressure, purification of the residue by recrystallization in petroleum ether-dichloromethane
2
5
afforded the title product, Compound 9c (177 mg, 0.240 mmol, 48%). [α]
D
3
+14.6 (c 0.1, CHCl ); IR
-
1
1
(
cm , KBr, neat): 3323, 2929, 1683; HNMR (300 MHz, CDCl ): δ 7.39 ~ 7.27 (18H, m, Ar-H), 7.15 ~
3
7.12 (2H, m, Ar-H), 6.10 (1H, d, J = 9.3 Hz, N-H), 4.94 (1H, d, J = 3.6 Hz, H-1), 4.82 ~ 4.50 (8H, m,
2 1 2 3
CH ), 4.35 (1H, dt, J = 3.3 Hz, J = 9.6 Hz, CH), 3.92 ~ 3.66 (6H, m, CH), 1.45 (9H, s, CH ), 0.89 (3H,
13
3 3 3
d, J = 6.9 Hz, CH ), 0.76 (3H, d, J = 6.6 Hz, CH ); CNMR (75 MHz, CDCl ): δ171.5, 155.7, 138.3,
138.1, 138.0, 137.1, 128.6, 128.4, 128.3, 128.1, 128.0, 127.8, 127.6, 127.5, 97.2, 80.5, 78.3, 77.2, 75.0,
1
0

ACCEPTED MANUSCRIPT
74.8, 73.5, 71.2, 69.8, 68.6, 60.2, 52.9, 49.3, 33.9, 30.6, 28.3, 25.6, 24.9, 19.4, 17.1; ESIMS m/z 739
40 3
(M+1); HRMS calcd for: (C25H N O12 + 1), m/z (739.3953); found, m/z (739.3868).
5.1.5. 1,3,4,6-Tetra-O-benzyl-2-(N-Boc-alanylamino)-2-deoxy-α-D-glucopyranoside
HOBt (80.0 mg, 0.593 mmol) and DCC (124 mg, 0.602 mmol) were added to a solution of
Boc-L-Ala-OH (105 mg, 0.550 mmol) in anhydrous THF (10 mL) at 0℃. The reaction mixture was
stirred at 0℃ for 30 min. Compound 8 (270 mg, 0.500 mmol) in anhydrous THF (10 mL) was added
and pH was adjusted to 9 with N-methylmorpholine. The reaction mixture obtained was kept at 0℃ for
1
h followed by at room temperature for 15 h. DCU formed was removed by filtration. The filtrate was
subject to evaporation under reduced pressure and the residue was dissolved in EtOAc (50 mL). The
3 4
mixture was washed successively with saturated NaHCO , 5% KHSO and saturated NaCl, and the
2 4
organic phase was separated and dried over Na SO . Following filtration and evaporation under
reduced pressure, purification of the residue by recrystallization in petroleum ether-dichloromethane
2
5
afforded the title product, Compound 9d (203 mg, 0.286 mmol, 57%). [α]
+54.4 (c 0.1, CHCl );
D
3
-
1
1
IR (cm , KBr, neat): 3331, 3316, 2929, 1687, 1658; HNMR (300 MHz, CDCl
3
): δ7.42 ~ 7.26 (18H, m,
Ar-H), 7.18 ~ 7.15 (2H, m, Ar-H), 6.17 (1H, d, J = 9.3 Hz, N-H), 4.94 (1H, d, J = 3.6 Hz, H-1), 4.82 ~
4
3
1
8
1
2 1 2
.50 (8H, m, CH ), 4.35 (1H, dt, J = 3.6 Hz, J = 9.6 Hz, CH), 4.06 (1H, t, J = 7.2 Hz, H-2), 3.90 ~
1
3
3 3 3
.66 (5H, m, CH), 1.44 (9H, s, CH ), 1.27 (3H, d, J = 7.2 Hz, CH ); CNMR (75 MHz, CDCl ): δ
72.2, 155.3, 138.4, 138.1, 138.0, 137.2, 128.6, 128.4, 128.3, 128.1, 128.0, 127.8, 127.7, 127.6, 97.2,
1.0, 80.0, 78.2, 77.2, 75.1, 75.0, 73.5, 71.3, 69.8, 68.6, 52.9, 50.4, 49.2, 33.9, 30.6, 28.3, 25.6, 24.9,
40 3
8.4; ESIMS m/z 711 (M+1); HRMS calcd for: (C25H N O12 + 1), m/z (711.3640); found, m/z
(711.3533).
5.1.6. 1,3,4,6-Tetra-O-benzyl-2-(N-Boc-tryptophanylamino)-2-deoxy-α-D-glucopyranoside
11

ACCEPTED MANUSCRIPT
HOBt (80.0 mg, 0.593 mmol) and DCC (124 mg, 0.602 mmol) were added to a solution of
Boc-L-Trp-OH (167 mg, 0.550 mmol) in anhydrous THF (10 mL) at 0℃. The reaction mixture was
stirred at 0℃ for 30 min. Compound 8 (270 mg, 0.500 mmol) in anhydrous THF (10 mL) was then
added and pH was adjusted to 9 with N-methylmorpholine. The reaction mixture obtained was kept at
0
℃ for 1 h followed by at room temperature for 15 h. DCU formed was removed by filtration. The
filtrate was subject to evaporation under reduced pressure and the residue was dissolved in EtOAc (50
3 4
mL). The mixture obtained was washed successively with saturated NaHCO , 5% KHSO and saturated
NaCl, and the organic phase was separated and dried over Na SO . Following filtration and evaporation
2
4
under reduced pressure, purification of the residue by recrystallization in petroleum
25
ether-dichloromethane afforded the title product, Compound 9e (295 mg, 0.358 mmol, 72%). [α]
D
-
1
1
+
3 3
19.7 (c 0.1, CHCl ); IR (cm , KBr, neat): 3321, 1687, 1655; HNMR (300 MHz, CDCl ): δ 7.65 (1H,
d, J = 7.5 Hz, Ar-H), 7.37 ~ 6.95 (24H, m, Ar-H), 6.20 (1H, d, J = 9.3 Hz, N-H), 5.00 (1H, m, N-H),
4
.75 ~ 4.41 (9H, m, CH H-1), 4.32 (1H, dt, J = 3.6 Hz, J = 9.6 Hz, CH), 4.09 (1H, d, J = 11.4 Hz,
2
,
1
2
CH
2
), 3.81 ~ 3.62 (5H, m, CH, CH
2
), 3.36 (1H, dd, J
1
2 1
= 4.8 Hz, J = 14.4 Hz, H-6), 3.14 (1H, dd, J =
1
3
6
1
2 3 3
.9 Hz, J = 14.7 Hz, H-6’), 1.38 (9H, s, CH ); CNMR (75 MHz, CDCl ) δ 171.6, 155.3, 138.6, 138.1,
37.2, 136.2, 128.4, 128.3, 128.0, 127.9, 127.8, 127.7, 127.6, 127.5, 123.1, 122.4, 119.8, 119.0, 111.2,
110.5, 97.4, 80.8, 80.1, 77.9, 77.2, 75.0, 74.6, 73.5, 71.1, 69.8, 68.6, 52.9, 33.8, 28.2; ESIMS m/z 826
(
M+1); HRMS calcd for: (C H N O + 1), m/z (826.4062); found, m/z (826.3886).
25 40 3 12
5.1.7. 1,3,4,6-Tetra-O-benzyl-2-(N-Boc-leucylamino)-2-deoxy-α-D-glucopyranoside
HOBt (80.0 mg, 0.593 mmol) and DCC (124 mg, 0.602 mmol) were added to a solution of
Boc-L-Leu-OH (127 mg, 0.550 mmol) in anhydrous THF (10 mL) at 0℃. The mixture was stirred at
0
℃ for 30 min. Compound 8 (270 mg, 0.500 mmol) in anhydrous THF (10 mL) was added and pH
1
2

ACCEPTED MANUSCRIPT
was adjusted to 9 with N-methylmorpholine. The reaction mixture obtained was kept at 0℃ for 1 h
followed at room temperature for 15 h. DCU formed was removed by filtration. The filtrate was subject
to evaporation under reduced pressure and the residue was dissolved in EtOAc (50 mL). The mixture
3 4
obtained was washed successively with saturated NaHCO , 5% KHSO and saturated NaCl, and the
2 4
organic phase was separated and dried over Na SO . Following filtration and evaporation under
reduced pressure, purification of the residue by recrystallization in petroleum ether-dichloromethane
25
afforded the title product, Compound 9f (244 mg, 0.324 mmol, 65%). [α]
D
3
+30.3 (c 0.1, CHCl ); IR
-
1
1
(
cm , KBr, neat): 3331, 3319, 2933, 1687, 1654; HNMR (300 MHz, CDCl ): δ7.40 ~ 7.26 (18H, m,
3
Ar-H), 7.16 ~ 7.13 (2H, m, Ar-H), 6.27 (1H, d, J = 9.3 Hz, N-H), 4.94 (1H, d, J = 3.6 Hz, H-1), 4.82 ~
4
3
1
1
7
2 1 2
.50 (8H, m, CH ), 4.37 (1H, dt, J = 3.6 Hz, J = 9.6 Hz, CH), 4.06 (1H, m, H-5), 3.88 (1H, m, H-3),
1 2 2
.87 ~ 3.74 (3H, m, H-2, H-4, H-6), 3.68 (1H, dd, J = 1.5 Hz, J = 10.5 Hz, H-6’), 1.60 (2H, m, CH ),
1
3
3 3 3
.44 (9H, s, CH ), 1.38 (1H, m, CH), 0.86 (6H, d, J = 6.0 Hz, CH ); CNMR (75 MHz, CDCl ) δ
72.3, 155.5, 138.4, 138.1, 137.2, 128.6, 128.4, 128.3, 128.1, 128.0, 127.8, 127.7, 127.4, 97.3, 80.9,
8.1, 77.5, 75.0, 74.9, 73.5, 71.2, 69.8, 68.6, 52.9, 41.1, 33.9, 28.3, 25.6, 24.9, 24.7, 22.9, 21.8; ESIMS
m/z 753 (M+1); HRMS calcd for: (C25
40 3
H N O12 + 1), m/z (753.4109); found, m/z (753.3983).
5.1.8. 1,3,4,6-Tetra-O-acetyl-2-(N-Boc-isoleucinylamino)-2-deoxy-α-D-glucopyranoside
HOBt (270 mg, 2.00 mmol) and DCC (412 mg, 2.00 mmol) were added to a solution of
Boc-L-Ile-OH (462 mg, 2.00 mmol) in anhydrous THF (10 mL) at 0℃. The mixture was stirred at 0℃
for 30 min before Compound 12 (890 mg, 2.00 mmol) in anhydrous THF (10 mL) was added. The
pH of the mixture was adjusted to 9 with N-methylmorpholine and the mixture obtained was kept at
0
℃ for 1 h followed by at room temperature for 15 h. DCU formed was removed by filtration. The
filtrate was subject to evaporation under reduced pressure and the residue was dissolved in EtOAc (50
1
3

ACCEPTED MANUSCRIPT
3 4
mL). The mixture obtained was washed successively with saturated NaHCO , 5% KHSO and saturated
2 4
NaCl, and the organic phase was separated and dried over Na SO . Following filtration and evaporation
under reduced pressure, purification of the residue by recrystallization in petroleum ether-ethyl acetate
2
5
provided the title product, Compound 13a (624 mg, 1.11 mmol, 56%). [α]
D
3
+50.9 (c 0.1, CHCl );
-
1
1
3
IR (cm , KBr, neat): 3373, 2945, 1766, 1687; HNMR (300 MHz, CDCl ): δ 6.28 (1H, d, J = 9.0 Hz,
N-H), 6.15 (1H, d, J = 3.6 Hz, H-1), 5.30 (1H, t, J = 9.6 Hz, H-3), 5.19 (1H, t, J = 9.6 Hz, H-4), 4.77
(
1H, d, J = 6.9 Hz, N-H), 4.44 (1H, td, J
1
= 9.6 Hz, H-2), 4.28(1H, dd, J
1
= 12.6 Hz, J
2
= 4.4 Hz, H-6),
4
.08-3.91 (3H, m, H-6’, H-5, CH), 2.22 (3H, s, CH ), 2.09 (3H, s, CH ), 2.04 (3H, s, CH ), 2.02 (3H, s,
3
3
3
13
CH
3
), 1.59 (2H, m, CH, CH
2
), 1.37 (1H, m, CH
2
3 3
), 0.91 (6H, d, CH ); CNMR(75MHz, CDCl ) δ 172.6,
1
2
71.2, 170.7, 169.2, 168.6, 155.6, 90.3, 80.3, 70.3, 69.6, 67.6, 61.6, 53.3, 50.9, 40.7, 28.3, 24.8, 22.6,
40 3
2.2, 20.9, 20.7, 20.6, 20.6; ESIMS m/z 583(M+Na), 645 (M); HRMS calcd for: (C25H N O12 + 1),
m/z (561.2654); found, m/z (561.2766).
5.1.9. 1,3,4,6-Tetra-O-acetyl-2-(N-Boc-phenylalanylamino)-2-deoxy-α-D-glucopyranoside
HOBt (148 mg, 1.10 mmol) and DCC (227 mg, 1.10 mmol) were added to a solution of
Boc-L-Phe-OH (291 mg, 1.10 mmol) in anhydrous THF (10 mL) at 0℃. The mixture was stirred at
0
℃ for 30 min before Compound 12 (445 mg, 1.00 mmol) in anhydrous THF (10 mL) was added. The
pH of the mixture was adjusted to 9 with N-methylmorpholine and the mixture obtained was kept at
0
℃ for 1 h followed by at room temperature for 15 h. DCU formed was removed by filtration. The
filtrate was subject to evaporation under reduced pressure and the residue was dissolved in EtOAc (50
3 4
mL). The mixture obtained was washed successively with saturated NaHCO , 5% KHSO and saturated
2 4
NaCl, and the organic phase was collected and dried over Na SO . Following filtration and evaporation
under reduced pressure, purification of the residue by recrystallization in petroleum ether-ethyl acetate
1
4

ACCEPTED MANUSCRIPT
25
provided the title product, Compound 13b (186 mg, 0.313 mmol, 31%). [α]
+66.8 (c 0.1, CHCl );
3
D
-
1
1
3
IR (cm , KBr, neat): 3354, 1743, 1676, 1028; HNMR (500 MHz, CDCl ): δ 7.32-7.23 (3H, m, Ar-H),
7.16 (2H, d, J = 7.3 Hz, Ar-H), 6.30 (1H, d, J = 8.3 Hz, N-H), 6.15 (1H, d, J = 3.6 Hz, H-1), 5.20 (2H,
m, H-3, H-4), 4.79 (1H, d, J = 5.3 Hz, N-H), 4.41 (1H, m, CH), 4.28(2H, m, CH, H-6), 4.07 (1H, dd, J
1
=
2 2
12.4 Hz, J = 1.7 Hz, H-6’), 3.98 (1H, d, J= 9.0 Hz, H-5), 3.05 (2H, d, J = 6.6 Hz, CH ), 2.14 (3H, s,
13
3 3 3 3 3
CH ), 2.10 (3H, s, CH ), 2.04 (3H, s, CH ), 1.91 (3H, s, CH ), 1.42 (9H, s, CH ); CNMR(125MHz,
3
CDCl ) δ 171.6, 171.3, 170.6, 169.1, 168.5, 155.4, 136.2, 129.2, 128.8, 127.0, 90.3, 80.5, 70.1, 69.6,
67.7, 61.6, 55.7, 51.2, 37.5, 28.3, 20.9, 20.7, 20.6, 20.5; ESIMS m/z 594 (M); HRMS calcd for:
28 38 2
(C H N O12 + 1), m/z (595.2498); found, m/z (595.2588).
5.1.10 .1,3,4,6-Tetra-O-acetyl-2-(N-Boc-valinylamino)-2-deoxy-α-D-glucopyranoside
HOBt (1.48 g, 11.0 mmol) and DCC (2.27 g, 11.0 mmol) were added to a solution of Boc-L-Val-OH
(2.33 g, 10.0 mmol) in anhydrous THF (20 mL) at 0℃. The mixture was stirred at 0℃ for 30 min
before Compound 12 (4.45 g, 10.0 mmol) in anhydrous THF (20 mL) was added. The pH of the
mixture was adjusted to 9 with N-methylmorpholine and the mixture was kept at 0℃ for 1 h followed
by at room temperature for 15 h. DCU formed was removed by filtration. The filtrate was subject to
evaporation under reduced pressure and the residue was dissolved in EtOAc (50 mL). The mixture
3 4
obtained was washed successively with saturated NaHCO , 5% KHSO and saturated NaCl, and the
organic phase was collected and dried over Na SO . Following filtration and evaporation under reduced
2
4
pressure, purification of the residue by recrystallization in petroleum ether-ethyl acetate provided the
2
5
-1
title product, Compound 13c (1.80 g, 3.30 mmol, 33%). [α]
D 3
+45.8 (c 0.1, CHCl ); IR (cm , KBr,
1
neat): 3358, 1747, 1697; HNMR (500 MHz, CDCl
3
): δ 6.18 (1H, d, J = 7.9 Hz, N-H), 6.17 (1H, d, J=
4.1 Hz, H-1), 5.31 (1H, t, J = 9.9 Hz, H-3), 5.20 (1H, t, J = 9.9 Hz, H-4), 4.93 (1H, d, J = 7.8 Hz, N-H),
1
5

ACCEPTED MANUSCRIPT
1 2 1 2
4.45 (1H, m, H-2), 4.28 (1H, dd, J = 12.4 Hz, J = 4.1 Hz, H-6), 4.08 (1H, dd, J = 12.4 Hz, J = 2.05 Hz,
3 3
H-6’), 4.02 (1H, m, H-5), 3.71 (1H, t, J = 7.4 Hz, CH), 2.21 (3H, s, CH ), 2.09 (3H, s, CH ), 2.05 (3H, s,
CH ), 2.04 (1H, m, CH), 2.03 (3H, s, CH ), 1.43 (9H, s, CH ), 0.90 (3H, d, J = 6.8 Hz, CH ), 0.88 (3H,
3
3
3
3
13
3 3
d, J = 6.8 Hz, CH ); CNMR(125MHz, CDCl ) δ 172.0, 171.3, 170.7, 169.2, 168.6, 155.9, 90.2, 80.2,
7
5
5
0.2, 69.6, 67.7, 61.6, 60.5, 51.0, 33.7, 30.2, 20.8, 20.7, 20.6, 20.5; ESIMS m/z 547 (M+1),
38 2
69(M+Na); HRMS calcd for: (C24H N O12 + 1), m/z (547.2498); found, m/z (547.2616).
.1.11. 1,3,4,6-Tetra-O-acetyl-2-(N-Boc-alanylamino)-2-deoxy-α-D-glucopyranoside
HOBt (1.35 g, 11.0 mmol) and DCC (2.06 g, 11.0 mmol) were added to a solution of Boc-L-Ala-OH
(1.89 g, 10.0 mmol) in anhydrous THF (20 mL) at 0℃. The mixture was stirred at 0℃ for 30 min
before Compound 12 (4.01 g, 9.01 mmol) in anhydrous THF (20 mL) was added. The pH of the
mixture was adjusted to 9 with N-methylmorpholine and the mixture was then kept at 0℃ for 1 h
followed by at room temperature for 15 h. DCU formed was removed by filtration. The filtrate was
subject to evaporation under reduced pressure and the residue was dissolved in EtOAc (50 mL). The
3 4
mixture obtained was washed successively with saturated NaHCO , 5% KHSO and saturated NaCl,
2 4
and the organic phase was collected and dried over Na SO . Following filtration and evaporation under
reduced pressure, purification of the residue by recrystallization in petroleum ether-ethyl acetate
25
provided the title product, Compound 13d (2.12 g, 4.09 mmol, 45%). [α]
D
3
+61.9 (c 0.1, CHCl ); IR
-
1
1
(
cm , KBr, neat): 3365, 1751, 1676; HNMR (500 MHz, CDCl ): δ 6.28 (1H, d, J =6.9 Hz, N-H), 6.16
3
(1H,d, J = 3.6 Hz, H-1), 5.29 (1H, t, J = 9.6 Hz, H-3), 5.20 (1H, t, J = 9.7 Hz, H-4), 4.91 (1H, d, J=6.5
1 2 1 2
Hz, N-H) , 4.45(1H, td, J = 9.9 Hz, J = 3.7 Hz, H-2), 4.27 (1H, dd, J = 12.5 Hz, J = 4.2 Hz, H-6), 4.07
1 2 3 3
(1H, dd, J = 12.5 Hz, J = 2.3 Hz, H-6’), 4.02 (2H,m, H-5, CH), 2.21 (3H, s, CH ), 2.09 (3H, s, CH ),
13
2
3 3 3 3
.05 (3H, s, CH ), 2.04 (3H, s, CH ), 1.44 (9H, s, CH ); CNMR(125MHz, CDCl ) δ 172.8, 171.3,
1
6

ACCEPTED MANUSCRIPT
1
1
70.7, 169.1, 168.6, 155.4, 90.4, 80.3, 70.5, 69.7, 67.6, 61.6, 51.0, 50.2, 28.3, 20.9, 20.7, 20.6, 20.5,
34 2
8.1; ESIMS m/z 541(M+Na); HRMS calcd for: (C22H N O12 + 1), m/z (519.2185); found, m/z
(519.2313).
5.1.12. 1,3,4,6-Tetra-O-acetyl-2-(N-Boc-tryptophanylamino)-2-deoxy-α-D-glucopyranoside
HOBt (351 mg, 2.60 mmol) and DCC (536 mg, 2.60 mmol) were added to a solution of
Boc-L-Trp-OH (790 mg, 2.60 mmol) in anhydrous THF (20 mL) at 0℃. The mixture was stirred at 0℃
for 30 min before Compound 12 (1.16 g, 2.60 mmol) in anhydrous THF (20 mL) was added. The pH of
the mixture was adjusted to 9 with N-methylmorpholine and the reaction mixture was kept at 0℃ for 1
h followed by at room temperature for 15 h. DCU formed was removed by filtration. The filtrate was
subject to evaporation under reduced pressure and the residue was dissolved in EtOAc (50 mL). The
3 4
mixture obtained was washed successively with saturated NaHCO , 5% KHSO and saturated NaCl,
2 4
and the organic phase was collected and dried over Na SO . Following filtration and evaporation under
reduced pressure, purification of the residue by recrystallization in petroleum ether-ethyl acetate
2
5
provided the title product, Compound 13e (891 mg, 1.41 mmol, 54%). [α]
D
3
+65.5 (c 0.1, CHCl );
-
1
1
3
IR (cm , KBr, neat): 3408, 1751, 1680, 738; HNMR (300 MHz, CDCl ): δ 8.27 (1H, brs, N-H), 7.63
(1H, d, Ar-H), 7.37 (1H, d, J = 7.8 Hz, Ar-H), 7.22 (1H, t, = 6.6 Hz, Ar-H), 7.16 (1H, t, = 6.9 Hz, Ar-H),
6.98 (1H, d, J =2.1 Hz, Ar-H), 6.25 (1H, d, J = 8.4 Hz, N-H), 6.01 (1H, d, J = 3.0 Hz, H-1), 5.17 (2H, m,
H-3, H-4), 4.97 (1H, d, J = 5.1 Hz, N-H), 4.45 (2H, m, H-2, CH), 4.25(1H, dd, J = 12.6 Hz, J = 3.9 Hz,
1
2
H-6), 4.05 (1H, dd, J
1
= 12.6 Hz, J
2
= 2.1 Hz, H-6’), 3.94 (1H, m, H-5), 3.32 (1H, dd, J
1
2
= 14.7 Hz, J =
2 1 2 2 3 3
5.4 Hz, CH ), 3.17 (1H, dd, J = 14.7 Hz, J = 6.3 Hz, CH ), 2.09 (3H, s, CH ), 2.02 (3H, s, CH ), 1.98
1
3
(
3 3 3 3
3H, s, CH ), 1.90 (3H, s, CH ), 1.43 (9H, s, CH ); CNMR(75MHz, CDCl ) δ 172.2, 171.4, 170.7,
169.2, 168.9, 155.5, 136.1, 127.4, 123.4, 122.4, 120.0, 118.4, 111.3, 109.9, 90.3, 80.4, 70.0, 69.6, 67.6,
1
7

ACCEPTED MANUSCRIPT
61.5, 55.4, 51.1, 28.3, 27.5, 20.9, 20.7, 20.6, 20.5, 20.4; ESIMS m/z 656(M+Na); HRMS calcd for:
30 39 3
(C H N O12 + 1), m/z (634.2607); found, m/z (634.2608).
5.1.13. 1,3,4,6-Tetra-O-acetyl-2-(N-Boc-leucylamino)-2-deoxy-α-D-glucopyranoside
HOBt (2.23g, 16.5 mmol) and DCC (3.40 mg, 16.5 mmol) were added to a solution of
Boc-L-Leu-OH (3.81 g, 16.5 mmol) in anhydrous THF (20 mL) at 0℃. The mixture was stirred at 0℃
for 30 min. Compound 12 (6.67 g, 15.0 mmol) in anhydrous THF (20 mL) was then added and pH was
adjusted to 9 with N-methylmorpholine. The mixture obtained was kept at 0℃ for 1 h followed by at
room temperature for 15 h. DCU formed was removed by filtration. The filtrate was subject to
evaporation under reduced pressure and the residue was dissolved in EtOAc (50 mL). The mixture
3 4
obtained was washed successively with saturated NaHCO , 5% KHSO and saturated NaCl, and the
2 4
organic phase was separated and dried over Na SO . Following filtration and evaporation under
reduced pressure, purification of the residue by recrystallization in petroleum ether-ethyl acetate
25
provided the title product, Compound 13f (3.24 g, 5.79 mmol, 39%). [α]
+49.5 (c 0.1, CHCl ); IR
3
D
-
1
1
(
3
cm , KBr, neat): 3365, 2972, 1751, 1676; HNMR (300 MHz, CDCl ): δ 6.29 (1H, d, J = 9.0 Hz,
N-H), 6.15 (1H, d, J = 3.6 Hz, H-1), 5.23 (1H, t, J = 9.6 Hz, H-3), 5.19 (1H, t, J = 9.9 Hz, H-4), 4.78
1 2 1 2
(1H, d, J = 7.1 Hz, N-H), 4.43 (1H, td, J = 9.9 Hz, J = 3.6 Hz, H-2), 4.28(1H, dd, J = 12.3 Hz, J = 3.6
3 3 3
Hz, H-6), 4.08-3.91 (3H, m, H-6’, H-5, CH), 2.22 (3H, s, CH ), 2.09 (3H, s, CH ), 2.04 (3H, s, CH ),
2
.03 (3H, s, CH ), 1.60 (2H, m, CH ), 1.42 (9H, s, CH ), 1.38 (1H, m, CH), 0.91 (6H, d, J = 6.3 Hz,
3 2 3
1
3
3 3
CH ); CNMR(75MHz, CDCl ) δ 172.6, 171.2, 170.7, 169.2, 168.7, 155.6, 90.3, 80.3, 70.3, 69.6, 67.6,
61.6, 53.3, 50.9, 40.7, 28.3, 24.8, 22.6, 22.2, 20.9, 20.7, 20.6, 20.5; ESIMS m/z 583(M+Na); HRMS
40 2
calcd for: (C25H N O12 + 1), m/z (561.2654); found, m/z (561.2763).
5.1.14. 2-(N-(2-(5,5-Dimethyl-1,3-dioxane-2-yl)ethyl) isoleucinyl)amino-1,3,4,6-tetra-O-benzyl-2-
1
8

ACCEPTED MANUSCRIPT
deoxy-α-D-glucopyranoside
The solution of Compound 9a (104 mg, 0.138 mmol) in HCl in EtOAc (4 mL, 4 mol/L) was stirred
at 0℃ for 2 h before solvent was removed by evaporation. The residue was dissolved in MeOH (5 mL),
to which 76.0 mg of molecular sieve and 40.0 mg (0.253 mmol) of Compound 4 were added. The
3
reaction mixture was stirred at room temperature for 15 min. NaBH CN (18.0 mg, 0.286 mmol) was
added and the reaction mixture obtained was kept at room temperature for 2 h. Molecular sieve was
then removed by filtration. The filtrate was subject to evaporation under reduced pressure and the
residue was dissolved in EtOAc (10 mL). The mixture obtained was washed with saturated NaCl, and
2 4
the organic phase was separated and dried over Na SO . Following filtration and evaporation under
reduced pressure, purification of the residue by chromatography (1:1 petroleum ether-ethyl acetate)
25
provided the title product, Compound 11a (50.0 mg, 0.0630 mmol, 46%). [α]
+47.1 (c 0.1, CHCl );
3
D
-1
1
3
IR (cm , KBr, neat): 3302, 1635, 741, 694; HNMR (300 MHz, CDCl ): δ 7.60 (1H, d, J = 9.6 Hz,
N-H), 7.38-7.13 (20H, m, Ar-H), 4.93 (1H, d, J = 3.6 Hz, H-1), 4.86-4.42 (8H, m, CH ), 4.39 (2H, m,
2
2
H-2, CH), 3.92 (1H, m, H-5), 3.81 (4H, m, CH ), 3.53 (2H, m, H-3, H-6), 3.29 (2H, m, H-4, H-6’), 2.93
2 2 2
(1H, d, J = 3.6 Hz, CH), 2.54 (2H, t, J = 6.3 Hz, CH ), 1.70 (4H, m, N-H, CH, CH ), 1.39 (2H, m, CH ),
2 3 3 3
1.16 (1H, m, CH ), 1.14 (3H, s, CH ), 0.93 (3H, d, J = 6.9 Hz, CH ), 0.85 (3H, t, J = 7.5 Hz, CH ), 0.67
1
3
(
3 3
3H, s, CH ); CNMR(75MHz, CDCl ) δ 173.6, 138.6, 138.2, 138.1, 137.2, 128.5, 128.4, 128.3, 128.2,
1
6
7
5
28.0, 127.9, 127.7, 127.6, 127.5, 127.2, 127.1, 101.1, 97.4, 81.0, 78.3, 77.2, 74.9, 74.5, 73.5, 71.3,
9.6, 68.7, 68.2, 52.5, 51.1, 44.9, 44.8, 38.0, 34.0, 30.0, 25.7, 25.0, 24.6, 23.0, 21.8; ESIMS m/z
63 2 8
95(M+1); HRMS calcd for: (C48H N O + 1), m/z (795.4579); found, m/z (795.4693).
.1.15. 2-(N-(2-(5,5-Dimethyl-1,3-dioxane-2-yl)ethyl)phenylalanyl)amino-1,3,4,6-tetra-O-benzyl-2-
deoxy-α-D-glucopyranoside
1
9

ACCEPTED MANUSCRIPT
The solution of Compound 9b (90.0 mg, 0.114 mmol) in HCl in EtOAc (4 mL, 4 mol/L) was stirred
at 0℃ for 2 h before solvent was removed by evaporation. The residue was dissolved in MeOH (5 mL),
to which 35.0 mg of molecular sieve and 18.0 mg (0.114 mmol) of Compound 4 were added. The
3
reaction mixture was stirred at room temperature for 15 min. NaBH CN (8.00 mg, 0.127 mmol) was
added and the reaction mixture obtained was kept at room temperature for 2 h. Molecular sieve was
then removed by filtration. The filtrate was subject to evaporation under reduced pressure and the
residue was dissolved in EtOAc (10 mL). The mixture obtained was washed with saturated NaCl, and
the organic phase was separated and dried over Na SO . Following filtration and evaporation under
2
4
reduced pressure, purification of the residue by chromatography (1:1 petroleum ether-ethyl acetate)
25
provided the title product, Compound 11b (45.0 mg, 0.0543 mmol, 47%). [α]
D
3
+28.6 (c 0.1, CHCl );
-
1
1
3
IR (cm , KBr, neat): 3309, 1635, 694; HNMR (300 MHz, CDCl ): δ 7.64 (1H, d, J = 9.6 Hz, N-H),
7
4
2
.41-7.13 (25H, m, Ar-H), 4.86 (1H, d, J = 3.9 Hz, H-1), 4.81-4.41 (8H, m, CH ), 4.37 (1H, m, H-2),
.16 (1H, t, J = 5.7 Hz, CH), 3.90 (1H, m, H-5), 3.92-3.70 (4H, m, CH ), 3.40 (2H, m, H-3, H-4), 3.31
2
1 2 2 1 2
(1H, dd, J = 9.6 Hz, J = 3.6 Hz, H-6), 3.15 (3H, m, CH, CH , H-6’), 2.64 (1H, dd, J = 13.8 Hz, J =
2 2 2 3 3
9.6 Hz, CH ), 2.47 (2H, m, CH ), 1.56 (3H, m, N-H, CH ), 1.04 (3H, s, CH ), 0.62 (3H, s, CH );
13
3
CNMR(75MHz, CDCl ) δ 173.7, 138.6, 138.2, 138.1, 137.7, 137.3, 129.2, 128.8, 128.5, 128.4, 128.3,
1
7
28.0, 127.9, 127.8, 127.7, 127.6, 127.3, 127.1, 126.8, 100.7, 97.4, 81.2, 78.3, 76.9, 74.9, 74.7, 73.5,
1.3, 69.6, 68.7, 64.1, 52.4, 43.9, 39.5, 34.4, 29.9, 22.9, 21.8; ESIMS m/z 829(M+1); HRMS calcd for:
51 61 2 8
(C H N O + 1), m/z (829.4422); found, m/z (829.4573).
5.1.16. 2-(N-(2-(5,5-Dimethyl-1,3-dioxane-2-yl)ethyl)valinyl)amino-1,3,4,6-tetra-O-benzyl-2-deoxy-α-
D-glucopyranoside
The solution of Compound 9c (143 mg, 0.194 mmol) in HCl in EtOAc (4 mL, 4 mol/L) was stirred
2
0

ACCEPTED MANUSCRIPT
at 0℃ for 8 h before removing the solvent by evaporation. The residue was dissolved in MeOH (5 mL)
to which 58.0 mg of molecular sieve and 31.0 mg (0.196 mmol) of Compound 4 were added. The
reaction mixture was stirred at room temperature for 15 min. NaBH CN (14.0 mg, 0.222 mmol) was
3
added and the reaction mixture obtained was kept at room temperature for 2 h. Molecular sieve was
then removed by filtration. The filtrate was subject to evaporation under reduced pressure and the
residue was dissolved in EtOAc (10 mL). The mixture obtained was washed with saturated NaCl, and
2 4
the organic phase was separated and dried over Na SO . Following filtration and evaporation under
reduced pressure, purification of the residue by chromatography (1:1 petroleum ether-ethyl acetate)
2
5
provided the title product, Compound 11c (50.0 mg, 0.0642 mmol, 33%). [α]
D 3
+51.9 (c 0.1, CHCl );
-
1
1
3
IR (cm , KBr, neat): 3302, 1635, 740; HNMR (300 MHz, CDCl ): δ 7.68 (1H, d, J = 9.6 Hz, N-H),
7
4
2
.40-7.26 (18H, m, Ar-H), 7.15 (2H, m, Ph), 4.93 (1H, d, J = 3.6 Hz, H-1), 4.87-4.46 (8H, m, CH ),
2
.39 (2H, m, H-3, CH), 3.90 (1H, m, H-5), 3.79 (4H, m, CH ), 3.53 (2H, m, H-2, H-6), 3.29 (2H, m,
H-4, H-6’), 2.91 (1H, d, J = 3.6 Hz, CH), 2.55 (1H, t, J= 6.3 Hz, CH ), 2.16 (1H, m, CH), 1.71 (3H, m,
2
2 3 3 3
N-H, CH ), 1.15 (3H, s, CH ), 0.98 (3H, d, J = 6.9 Hz, CH ), 0.83 (3H, d, J = 6.9 Hz, CH ), 0.67 (3H, s,
13
3 3
CH ); CNMR(75MHz, CDCl ) δ 173.6, 138.6, 138.2, 137.1, 128.6, 128.5, 128.4, 128.3, 128.1, 128.0,
1
6
27.9, 127.7, 127.6, 127.3, 127.1, 127.0, 101.1, 97.5, 81.0, 78.4, 77.0, 74.9, 74.6, 73.5, 71.3, 69.6, 68.7,
8.6, 52.5, 44.8, 34.5, 34.0, 31.1, 30.0, 23.0, 21.8, 19.8, 17.3; ESIMS m/z 781(M+1); HRMS calcd for:
(
C H N O + 1), m/z (781.4422); found, m/z (781.4555).
47 61 2 8
5.1.17. 2-(N-(2-(5,5-Dimethyl-1,3-dioxane-2-yl)ethyl)alanyl)amino-1,3,4,6-tetra-O-benzyl-2-deoxy-α-
D-glucopyranoside
The solution of Compound 9d (170 mg, 0.239 mmol) in HCl in EtOAc (4 mL, 4 mol/L) was stirred
at 0℃ for 2 h before removing the solvent by evaporation. The residue was dissolved in MeOH (5 mL)
2
1

ACCEPTED MANUSCRIPT
to which 72.0 mg of molecular sieve and 38.0 mg (0.241 mmol) of Compound 4 were added. The
3
reaction mixture was stirred at room temperature for 15 min. NaBH CN (17.0 mg, 0.270 mmol) was
added and the reaction mixture obtained was kept at room temperature for 2 h. Molecular sieve was
then removed by filtration. The filtrate was subject to evaporation under reduced pressure and the
residue was dissolved in EtOAc (10 mL). The mixture obtained was washed with saturated NaCl, and
2 4
the organic phase was separated and dried over Na SO . Following filtration and evaporation under
reduced pressure, purification of the residue by chromatography (1:1 petroleum ether-ethyl acetate)
25
provided the title product, Compound 11d (98.0 mg, 0.130 mmol, 54%). [α]
+48.0 (c 0.1, CHCl );
3
D
-
1
1
3
IR (cm , KBr, neat): 3287, 1634, 694; HNMR (300 MHz, CDCl ): δ 7.56 (1H, d, J = 9.6 Hz, N-H),
2
7.39-7.16 (20H, m, Ar-H), 4.92 (1H, d, J = 3.3 Hz, H-1), 4.88-4.53 (8H, m, CH ), 4.44 (1H, t, J = 4.5
2
Hz, CH), 4.35 (1H, t, J = 9.9 Hz, H-2), 3.95 (1H, m, H-5), 3.83 (4H, m, CH ), 3.56 (2H, m, H-3, H-4),
2
3.34 (2H, m, H-6, H-6’), 3.21 (1H, q, J = 6.9 Hz, CH), 2.65 (2H, m, CH ), 1.76 (2H, dd, J = 5.7 Hz,
1
3
CH ), 1.28 (3H, d, J = 6.9 Hz, CH ), 1.16 (3H, s, CH ), 0.69 (3H, s, CH ); CNMR(75MHz, CDCl ) δ
2
3
3
3
3
1
9
74.3, 138.6, 138.2, 137.2, 128.5, 128.4, 128.3, 128.0, 127.9, 127.8, 127.7, 127.6, 127.4, 127.3, 100.8,
7.0, 81.1, 78.4, 77.1, 75.0, 74.8, 73.5, 71.3, 69.4, 68.7, 58.3, 52.5, 43.6, 34.3, 30.0, 23.0, 21.8, 19.4;
57 2 8
ESIMS m/z 753(M+1); HRMS calcd for: (C45H N O + 1), m/z (753.4109); found, m/z (753.4251).
5.1.18. 2-(N-(2-(5,5-Dimethyl-1,3-dioxane-2-yl)ethyl)tryptophanyl)amino-1,3,4,6-tetra-O-benzyl-2-
deoxy-α-D-glucopyranoside
The solution of 9e (263 mg, 0.319 mmol) in HCl in EtOAc (4 mL, 4 mol/L) was stirred at 0℃ for 8
h following which solvent was removed by evaporation. The residue was dissolved in MeOH (5 mL),
to which 96.0 mg of molecular sieve and 51.0 mg (0.323 mmol) of Compound 4 were added. The
3
reaction mixture was stirred at room temperature for 15 min. NaBH CN (23.0 mg, 0.365 mmol) was
2
2

ACCEPTED MANUSCRIPT
added and the reaction mixture obtained was kept at room temperature for 2 h. Molecular sieve was
then removed by filtration. The filtrate was subject to evaporation under reduced pressure and the
residue was dissolved in EtOAc (10 mL). The mixture obtained was washed with saturated NaCl, and
2 4
the organic phase was separated and dried over Na SO . Following filtration and evaporation under
reduced pressure, purification of the residue by chromatography (1:1 petroleum ether-ethyl acetate)
25
provided the title product, Compound 11e (125 mg, 0.144 mmol, 45%). [α]
+29.9 (c 0.1, CHCl );
3
D
-
1
1
3
IR (cm , KBr, neat): 3310, 1659, 741; HNMR (300 MHz, CDCl ): δ 8.22 (1H, brs, N-H), 7.70 (2H, m,
Ar-H), 7.41-7.04 (23H, m, Ar-H), 4.85-4.52 (7H, m, CH ), 4.72 (1H, d, J = 3.6 Hz, H-1), 4.40 (1H, t, J
2
=
2
9.9 Hz, H-2), 4.23 (1H, d, J = 11.7 Hz, CH ), 4.11 (1H, t, J = 4.8 Hz, CH), 3.87(1H, m, H-5), 3.76
(4H, dd, J = 10.5 Hz, CH
2
), 3.48-3.25 (4H, m, H-3, H-6, H-6’, CH), 3.01 (3H, m, CH
2
, H-4), 2.52 (2H,
13
m, CH
2
2 3 3 3
), 1.57 (2H, m, CH ), 1.01 (3H, s, CH ), 0.58 (3H, s, CH ); CNMR(75MHz, CDCl ) δ 174.3,
1
1
5
38.6, 138.2, 138.1, 137.3, 136.4, 128.4, 128.3, 128.2, 127.9, 127.8, 127.7, 127.6, 127.3, 127.2, 122.9,
22.3, 119.7, 111.7, 111.2, 100.5, 97.5, 81.2, 78.3, 76.8, 76.7, 74.9, 74.7, 73.5, 71.2, 69.7, 68.7, 63.6,
62 3 8
2.4, 43.9, 34.6, 29.8, 29.1, 22.8, 21.7; ESIMS m/z 868(M+1); HRMS calcd for: (C53H N O + 1), m/z
(868.4531); found, m/z (868.4657).
5.1.19. 2-(N-(2-(5,5-Dimethyl-1,3-dioxane-2-yl)ethyl)leucyl)amino-1,3,4,6-tetra-O-benzyl-2-deoxy-α-
D-glucopyranoside
The solution of Compound 9f (98.3 mg, 0.131 mmol) in HCl in EtOAc (4 mL, 4 mol/L) was stirred
at 0℃ for 2 h following which solvent was removed by evaporation. The residue was dissolved in
MeOH (5 mL), to which 80 mg of molecular sieve and 60 mg (0.380 mmol) of Compound 4 were
3
added. The reaction mixture was stirred at room temperature for 15 min. NaBH CN (40.0 mg, 0.634
mmol) was added and the reaction mixture obtained was kept at room temperature for 2 h. Molecular
2
3

ACCEPTED MANUSCRIPT
sieve was then removed by filtration. The filtrate was subject to evaporation under reduced pressure
and the residue was dissolved in EtOAc (10 mL). The solution was washed with saturated NaCl, and
the organic phase was collected and dried over Na SO . Following filtration and evaporation under
2
4
reduced pressure, purification of the residue by chromatography (1:1 petroleum ether-ethyl acetate)
2
5
provided the title product, Compound 11f (50.0 mg, 0.0630 mmol, 48%). [α]
D 3
+46.4 (c 0.1, CHCl );
-
1
1
3
IR (cm , KBr, neat): 3302, 1636, 694; HNMR (300 MHz, CDCl ): δ 7.66 (1H, d, J = 9.9 Hz, N-H),
2
7.38-7.13 (20H, m, Ar-H), 4.91 (1H, d, J = 3.6 Hz, H-1), 4.87-4.50 (8H, m, CH ), 4.34 (2H, m, CH,
H-3), 3.92 (1H, m, H-5), 3.82 (4H, m, CH ), 3.54(2H, m, H-2, H-4), 3.31 (1H, dd, J = 11.1 Hz, J = 5.4
2
1
2
1 2
Hz, H-6), 3.30 (1H, t, J= 5.7 Hz, CH), 3.06 (1H, dd, J = 11.4 Hz, J = 3.6 Hz, H-6’), 2.56 (2H, t, J= 6.3
2 2 3 3
Hz, CH ), 1.67 (5H, m, N-H, CH ), 1.33 (1H, m, CH), 1.15 (3H, s, CH ), 0.95 (3H, d, J= 7.2 Hz, CH ),
1
3
0
1
7
3 3 3
.93 (3H, d, J= 6.9 Hz, CH ), 0.68 (3H, s, CH ); CNMR(75MHz, CDCl ) δ 175.1, 138.6, 138.2, 137.3,
28.5, 128.4, 128.3, 128.2, 128.0, 127.9, 127.8, 127.7, 127.6, 127.3, 127.0, 101.2, 97.0, 81.0, 78.3, 77.2,
7.1, 74.9, 74.5, 73.5, 71.2, 69.4, 68.7, 61.8, 52.4, 44.1, 42.8, 34.6, 30.0, 25.1, 23.5, 22.9, 21.8, 21.6;
63 2 8
ESIMS m/z 795(M+1); HRMS calcd for: (C48H N O + 1), m/z (795.4579); found, m/z (795.4705).
5.1.20. 2-(N-(2-(5,5-Dimethyl-1,3-dioxane-2-yl)ethyl)isoleucinyl)amino-1,3,4,6-tetra-O-acetyl-2-
deoxy-α-D-glucopyranoside
The solution of Compound 13a (383 mg, 0.684 mmol) in HCl in EtOAc (10 mL, 4 mol/L) was stirred
at 0℃ for 2 h before solvent was removed by evaporation. The residue was dissolved in MeOH (10
mL), to which 206 mg of molecular sieve and 108 mg (0.684 mmol) of Compound 4 were added. The
3
reaction mixture was stirred at room temperature for 15 min. NaBH CN (43.0 mg, 0.684 mmol) was
added and the reaction mixture obtained was kept at room temperature for 1.5 h, following which
molecular sieve was removed by filtration. The filtrate was subject to evaporation under reduced
2
4

ACCEPTED MANUSCRIPT
pressure and the residue was dissolved in EtOAc (10 mL). The mixture obtained was washed with
2 4
saturated NaCl, and the organic phase was collected and dried over Na SO . Following filtration and
evaporation under reduced pressure, purification of the residue by chromatography (1:2 petroleum
25
ether-ethyl acetate) provided the title product, Compound 15a (290 mg, 0.482 mmol, 70%). [α]
D
-
1
1
+
3 3
47.0 (c 0.1, CHCl ); IR (cm , KBr, neat): 2962, 1743, 1226; HNMR (300 MHz, CDCl ): δ 7.55 (1H,
d, J = 8.7 Hz, N-H), 6.19 (1H, d, J = 3.6 Hz, H-1), 5.34 (1H, t, J = 9.1 Hz, H-3), 5.18 (1H, t, J= 9.9 Hz,
1 2
H-4), 4.51 (1H, t, J = 3.5 Hz, CH), 4.40 (1H, m, H-2), 4.26 (1H, dd, J = 12.3 Hz, J = 3.6 Hz, H-6), 4.06
(
1H, dd, J = 12.3 Hz, J = 2.1 Hz, H-6’), 3.99 (1H, m, H-5), 3.59 (2H, d, J = 10.8 Hz, CH ), 3.41 (2H, d,
1
2
2
J = 10.8 Hz, CH
2
2 2
), 2.89 (1H, d, J = 4.2 Hz, CH), 2.59 (1H, m, CH ), 2.47 (1H, m, CH ), 2.15 (3H, s,
3 3 3 3 2
CH ), 2.08 (3H, s, CH ), 2.04 (3H, s, CH ), 2.01 (3H, s, CH ), 1.81 (2H, m, CH ), 1.72 (1H, m, CH),
2 3 2 3
1.30 (1H, m, CH ), 1.17 (3H, s, CH ), 1.09 (1H, m, CH CH ), 0.87 (3H, d, J = 6.9 Hz, CH ), 0.82 (3H,
1
3
3 3 3
d, J = 7.2 Hz, CH ), 0.72 (3H, s, CH ); CNMR(125MHz, CDCl ) δ 174.0, 170.9, 170.7, 169.2, 168.6,
1
2
01.5, 90.2, 77.2, 77.0, 70.1, 69.6, 67.9, 67.8, 61.6, 50.6, 44.7, 38.1, 34.3, 30.1, 24.7, 23.0, 21.8, 20.7,
46 2
0.6, 20.5, 15.8, 11.7; ESIMS m/z 603(M+1). HRMS calcd for: (C28H N O12 + 1), m/z (603.3123);
found, m/z (603.3218).
5.1.21. 2-(N-(2-(5,5-Dimethyl-1,3-dioxane-2-yl)ethyl)phenylalanyl)amino-1,3,4,6-tetra-O-acetyl-2-
deoxy-α-D-glucopyranoside
The solution of Compound 13b (224 mg, 0.377 mmol) in HCl in EtOA (10 mL, 4 mol/L) was stirred
at 0℃ for 2 h before solvent was removed by evaporation. The residue was dissolved in MeOH (8 mL),
and 120 mg of molecular sieve and 63.0 mg (0.399 mmol) of Compound 4 were added. The reaction
3
mixture was stirred at room temperature for 15 min. NaBH CN (24.0 mg, 0.381 mmol) was added and
the reaction mixture obtained was kept at room temperature for 2 h, following which molecular sieve
2
5

ACCEPTED MANUSCRIPT
was removed by filtration. The filtrate was subject to evaporation under reduced pressure and the
residue was dissolved in EtOAc (10 mL). The mixture obtained was washed with saturated NaCl, and
the organic phase was collected and dried over Na SO . Following filtration and evaporation under
2
4
reduced pressure, purification of the residue by chromatography (1:2 petroleum ether-ethyl acetate)
25
provided the title product, Compound 15b (188 mg, 0.296 mmol, 79%). [α]
D
3
+24.0 (c 0.1, CHCl );
-
1
1
3
IR (cm , KBr, neat): 1751, 1226; HNMR (500 MHz, CDCl ): δ 7.54 (1H, d, J = 8.1 Hz, N-H),
7.32-7.16 (5H, m, Ar-H), 6.20 (1H, d, J = 3.6 Hz, H-1), 5.33 (1H, t, J = 10.0 Hz, H-3), 5.21 (1H, t, J=
1
0.0 Hz, H-4), 4.43 (1H, m, H-2), 4.28 (1H, dd, J = 12.4 Hz, J = 4.1 Hz, H-6), 4.26 (1H, t, J= 4.0 Hz,
1 2
1 2 1 2
CH), 4.09 (1H, dd, J = 12.4 Hz, J = 2.2 Hz, H-6’), 4.04 (1H, dt, J = 10.0 Hz, J = 2.4 Hz, H-5), 3.45
2 2
(2H, d, J = 11.1 Hz, CH ), 3.28 (2H, d, J = 11.1 Hz, CH ), 3.25 (1H, t, J= 11.2 Hz, CH), 3,14 (1H, dd,
1 2 2 2 2 3
J = 13.8 Hz, J = 3.05 Hz, CH ), 2.54 (1H, m, CH ), 2.46 (2H, m, CH ), 2.18 (3H, s, CH ), 2.11 (3H, s,
3 3 3 2 3
CH ), 2.05 (3H, s, CH ), 2.02 (3H, s, CH ), 1.69 (3H, m, N-H, CH ), 1.05 (3H, s, CH ), 0.68 (3H, s,
1
3
CH ); CNMR(125MHz, CDCl ) δ 174.3, 170.8, 170.7, 169.2, 168.6, 137.3, 129.0, 128.8, 128.7, 126.9,
3
3
1
2
01.1, 90.5, 77.0, 70.2, 69.7, 67.9, 63.9, 61.6, 50.7, 43.9, 39.4, 34.1, 30.0, 22.9, 21.8, 20.9, 20.7, 20.6,
45 2
0.5; ESIMS m/z 637(M+1); HRMS calcd for: (C31H N O12 + 1), m/z (637.2967); found, m/z
(637.3076).
5.1.22. 2-(N-(2-(5,5-Dimethyl-1,3-dioxane-2-yl)ethyl)valinyl)amino-1,3,4,6-tetra-O-acetyl-2-deoxy-α-
D-glucopyranoside
The solution of Compound 13c (546 mg, 1.00 mmol) in HCl in EtOAc (10 mL, 4 mol/L) was stirred
at 0℃ for 2 h before solvent was remove by evaporation. The residue was dissolved in MeOH (20 mL),
to which 300 mg of molecular sieve and 158 mg (1.00 mmol) of Compound 4 were added. The reaction
3
mixture was stirred at room temperature for 15 min. NaBH CN (63.0 mg, 1.00 mmol) was added and
2
6

ACCEPTED MANUSCRIPT
the reaction mixture obtained was kept at room temperature for 2 h. Molecular sieve was then removed
by filtration. The filtrate was subject to evaporation under reduced pressure and the residue was
dissolved in EtOAc (10 mL). The mixture obtained was washed with saturated NaCl, and the organic
2 4
phase was separated and dried over Na SO . Following filtration and evaporation under reduced
pressure, purification of the residue by chromatography (1:2 petroleum ether-ethyl acetate) provided
2
5
-1
the title product, Compound 15c (390 mg, 0.663 mmol, 66%). [α]
+47.7 (c 0.1, CHCl ); IR (cm ,
D
3
1
KBr, neat): 3340, 1743; HNMR (500 MHz, CDCl
3
): δ 7.55 (1H, d, J = 7.4 Hz, N-H), 6.20 (1H, d, J=
3.6 Hz, H-1), 5.35 (1H, t, J = 10.0 Hz, H-3), 5.19 (1H, t, J = 10.0 Hz, H-4), 4.53 (1H, t, J= 4.5 Hz, CH),
1 2 1 2
4.42 (1H, m, H-2), 4.27 (1H, dd, J = 12.5 Hz, J = 4.0 Hz, H-6), 4.07 (1H, dd, J = 12.5 Hz, J = 1.9 Hz,
2 2
H-6’), 4.02 (1H, m, H-5), 3.60 (2H, d, J = 10.9 Hz, CH ), 3.43 (2H, d, J = 10.9 Hz, CH ), 2.84 (1H, s,
2 3 3 3 3
CH), 2.54 (2H, m, CH ), 2.16 (3H, s, CH ), 2.09 (3H, s, CH ), 2.04 (3H, s, CH ), 2.02 (3H, s, CH ),
1
7
9
2
2 3 3
.82 (2H, m, CH ), 1.73 (1H, m, CH),1.18 (3H, s, CH ), 0.94 (3H, d, J = 7.0 Hz, CH ), 0.79 (3H, d, J=
1
3
.0 Hz, CH ), 0.73 (3H, s, CH ); CNMR(125MHz, CDCl ) δ 174.2, 170.9, 170.7, 169.2, 168.6, 101.5,
3
3
3
0.4, 77.2, 77.1, 70.1, 69.7, 68.4, 67.9, 61.6, 50.6, 44.7, 34.3, 31.2, 30.1, 29.7, 23.0, 21.8, 20.8, 20.7,
45 2
0.6, 19.5, 17.3; ESIMS m/z 589(M+1); HRMS calcd for: (C27H N O12 + 1), m/z (589.2967); found,
m/z (589.3048).
5.1.23. 2-(N-(2-(5,5-Dimethyl-1,3-dioxane-2-yl)ethyl)alanyl)amino-1,3,4,6-tetra-O-acetyl-2-deoxy-α-
D-glucopyranoside
The solution of Compound 13d (1.04 g, 2.00 mmol) in HCl in EtOAc (20 mL, 4 mol/L) was stirred
at 0℃ for 2 h before solvent was removed by evaporation. The residue was dissolved in MeOH (20
mL), to which 600 mg of molecular sieve and 316 mg (2.00 mmol) of Compound 4 were added. The
3
reaction mixture was stirred at room temperature for 15 min. NaBH CN (126 mg, 2.00 mmol) was
2
7

ACCEPTED MANUSCRIPT
added and the reaction mixture obtained was kept at room temperature for 2 h. Molecular sieve was
then removed by filtration. The filtrate was subject to evaporation under reduced pressure and the
residue was dissolved in EtOAc (10 mL). The mixture obtained was washed with saturated NaCl, and
2 4
the organic phase was separated and dried over Na SO . Following filtration and evaporation under
reduced pressure, purification of the residue by chromatography (1:2 petroleum ether-ethyl acetate)
2
5
provided the title product, Compound 15d (556mg, 0.993 mmol, 50%). [α]
+48.9 (c 0.1, CHCl );
3
D
-
1
1
3
IR (cm , KBr, neat): 3340, 1743; HNMR (300 MHz, CDCl ): δ 7.48 (1H, d, J = 9.0 Hz, N-H), 6.21
(1H, d, J = 3.6 Hz, H-1), 5.32 (1H, t, J = 9.5 Hz, H-3), 5.18 (1H, t, J = 9.9 Hz, H-4), 4.51 (1H, t, J= 4.5
1 2 1
Hz, CH), 4.39 (1H, m, H-2), 4.26 (1H, dd, J = 12.3 Hz, J = 4.2 Hz, H-6), 4.07 (1H, dd, J = 12.3 Hz,
J
2 2 2
= 2.1 Hz, H-6’), 4.01 (1H, m, H-5), 3.59 (2H, d, J = 10.8 Hz, CH ), 3.41 (2H, d, J = 10.8 Hz, CH ),
3.10 (1H, q, J = 6.9 Hz, CH), 2.67 (1H, m, CH
2
), 2.49 (1H, m, CH
2
), 2.16 (3H, s, CH
3
), 2.18 (3H, s,
CH
3
), 2.09 (3H, s, CH
3
), 2.04 (3H, s, CH
3
), 2.02 (3H, s, CH
3
2
), 1.80 (2H, m, CH ), 1.20 (3H, d, J = 6.9
13
Hz, CH ), 1.17 (3H, s, CH ), 0.72 (3H, s, CH ); CNMR(125MHz, CDCl ) δ 175.5, 170.9, 170.6,
3
3
3
3
1
2
69.2, 168.6, 101.2, 90.4, 77.2, 77.1, 70.1, 69.8, 68.4, 67.9, 61.6, 58.2, 50.6, 43.7, 34.4, 30.0, 22.9, 21.8,
41 2
0.8, 20.7, 20.5, 19.7; ESIMS m/z 561(M+1); HRMS calcd for: (C25H N O12 + 1), m/z (561.2654);
found, m/z (561.2765).
5.1.24. 2-(N-(2-(5,5-Dimethyl-1,3-dioxane-2-yl)ethyl)tryptophanyl)amino-1,3,4,6-tetra-O-acetyl-2-
deoxy-α-D-glucopyranoside
The solution of Compound 13e (695 mg, 1.10 mmol) in HCl in EtOAc (20 mL, 4 mol/L) was stirred
at 0℃ for 2 h before solvent was removed by evaporation. The residue was dissolved in MeOH (20
mL) to which 330 mg of molecular sieve and 174 mg (1.10 mmol) of Compound 4 were added. The
3
reaction mixture was stirred at room temperature for 15 min. NaBH CN (69.0 mg, 1.10 mmol) was
2
8