Synthesis and glycosidase inhibition evaluation of (3S,4S)-3-((R)-1,2-dihydroxyethyl)pyrrolidine-3,4-diol

Article abstract of DOI:10.1016/j.carres.2016.08.003

A new azasugar (3S,4S)-3-((R)-1,2-dihydroxyethyl)pyrrolidine-3,4-diol (1) was obtained from commercially available D-glucose using one-pot reductive cyclization as a key step. The target product, i.e., the iminosugar isomer, was obtained in 10 steps and 24.3% overall yield. Only three column chromatography purifications were needed in this synthesis. The biological activity of the target molecule as glycosidase inhibitor was studied, but the inhibitory activity against four glycosidases was not good (IC₅₀?>?100?μM).

Full text of DOI:10.1016/j.carres.2016.08.003

Accepted Manuscript
Synthesis and glycosidase inhibition evaluation of (3S,4S)-3-((R)-1,2-
dihydroxyethyl)pyrrolidine-3,4-diol
En Zhang, Peng-Yan Bai, Wei Sun, Shang Wang, Ming-Ming Wang, Shuai-Min Xu,
Hong-Min Liu
PII:
S0008-6215(16)30282-8
10.1016/j.carres.2016.08.003
CAR 7243
DOI:
Reference:
To appear in: Carbohydrate Research
Received Date: 9 April 2016
Revised Date: 26 July 2016
Accepted Date: 2 August 2016
Please cite this article as: E. Zhang, P.-Y. Bai, W. Sun, S. Wang, M.-M. Wang, S.-M. Xu, H.-M. Liu,
Synthesis and glycosidase inhibition evaluation of (3S,4S)-3-((R)-1,2-dihydroxyethyl)pyrrolidine-3,4-diol,
Carbohydrate Research (2016), doi: 10.1016/j.carres.2016.08.003.
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Graphical abstract
A new azasugar isomer (3S,4S)-3-((R)-1,2-dihydroxyethyl)pyrrolidine-3,4-diol was
obtained from D-glucose in ten steps and 24.3% overall yield using one-pot reduction
cyclization as the key step. Only three column chromatography purifications were
needed in this synthesis. Biological activity evaluation as inhibitor against glycosidase
were studied but the results were not ideal.

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Synthesis and glycosidase inhibition evaluation of
(3S,4S)-3-((R)-1,2-dihydroxyethyl)pyrrolidine-3,4-diol
En Zhanga,b,*, Peng-Yan Baia, Wei Suna, Shang Wanga, Ming-Ming Wanga, Shuai-Min
Xua, Hong-Min Liua,b,*
aSchool of Pharmaceutical Sciences, Institute of Drug Discovery and Development, Key
Laboratory of Advanced Pharmaceutical Technology, Ministry of Education of China, Zhengzhou
University, Zhengzhou 450001, PR China
bCollaborative Innovation Center of New Drug Research and Safety Evaluation, Henan Province,
Zhengzhou 450001, PR China
*Corresponding authors.
E-mail addresses: zhangen@zzu.edu.cn (E. Zhang); liuhm@zzu.edu.cn (H.-M. Liu).
Abstract
A new azasugar (3S,4S)-3-((R)-1,2-dihydroxyethyl)pyrrolidine-3,4-diol (1) was
obtained from commercially available D-glucose using one-pot reductive cyclization
as a key step. The target product, i.e., the iminosugar isomer, was obtained in 10 steps
and 24.3% overall yield. Only three column chromatography purifications were
needed in this synthesis. The biological activity of the target molecule as glycosidase
inhibitor was studied, but the inhibitory activity against four glycosidases was not
good (IC50 > 100 µM).
Keywords: Azasugar, One-pot reaction, Reductive cyclization, Isomer

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1. Introduction
Many sugars with the ring oxygen replaced by nitrogen, i.e., azasugars or
iminosugars,1 occur widely in plants and microorganisms.2 Azasugars are
carbohydrate analogs in which the anomeric hydroxyl group has been preserved or
removed, and they include polyhydroxylated pyrrolidines and piperidines.3
Iminosugars are potent inhibitors of common carbohydrate-processing enzymes
and have significant glycosidase and glycosyltransferase inhibitory activities.4
Glycosidases and glycosyltransferases participate in sugar processing and synthesis. It
is therefore important to study and develop compounds that inhibit glycosidases.
Glycosidase inhibitors have attracted much attention because they are potentially
antidiabetic,5 antiviral,6 and anticancer agents,7 and they have potential in obesity
therapy.5 Recently, many novel glycosidase inhibitors used in herbal medicine,
including polysaccharides, alkaloids, glycosides and polypeptides, have been
screened.8 Because of their important biological activities and potential applications,
the study of azasugars and their derivatives has become an important research topic in
organic and pharmaceutical chemistry.9 Recent studies have shown that azasugars can
be used to treat a wide range of conditions, including diabetes, viral infections, tumor
metastasis, lysosomal storage disorders and cystic fibrosis.10, 11
As a result from their potent inhibitory activities, a large number of natural and
non-natural structural analogs have been prepared and tested as therapeutically potent
inhibitors. Chiral carbohydrate or non-sugar compounds are useful for studying

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azasugar synthesis.12
Some azasugars are used as drugs, e.g., N-hydroxyethyl DNJ (miglitol, Fig. 1)13
and NB-DNJ (miglustat, Fig. 1)14 are widely used in clinical practice for the treatment
of type-II diabetes and Gaucher’s disease (a severe genetic disease caused lysosomal
storage disorder), respectively. The galactofuranose pyrrolidine analog 2, which is an
inhibitor of UDP-Gal mutase and intervenes in the biosynthesis of mycobacterial
galactan, has been obtained.15 The synthesis and biological evaluation of new
inhibitors (3 and 4, Fig. 1) of UDP-Galf transferase, which is a significant enzyme in
Mycobacterium tuberculosis cell wall biosynthesis, have been reported;16 ring-closing
metathesis reactions were the key step in generating novel compounds. A considerable
number of nitrogen-containing azasugar isomers have attracted attention because of
their importance as glycosidase inhibitors. Polyhydroxylated piperidines are excellent
glycosidase inhibitors.17 Azasugar isomers have the potential to be good glycosidase
inhibitors.
In terms of diversity-oriented synthesis, it is important to develop new strategies
for synthesizing novel azasugar isomers, especially with high stereoselectivity. During
our investigations of α-glucosidase inhibitors18 and their synthesis from sugars,19 we
developed an effective synthetic method for the preparation of new azasugars based
on deprotection and reductive amination in one pot. The target compound (1) was
obtained in 10 steps and 24.3% overall yield. Only three column chromatography
purifications were needed in this synthesis. The biological activity of the target

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molecule as a glycosidase inhibitor was studied but the inhibitory activity against four
glycosidases was not good (IC50 > 100 µM).
Fig. 1. Structures of some iminosugars.
2. Results and discussion
2.1 Synthesis of a new azasugar isomer (3S,4S)-3-((R)-1,2-dihydroxyethyl)
pyrrolidi-ne-3,4-diol (1)
In this study, a new azasugar (1) was synthesized from
(Scheme 1). 1,2;5,6-Di-O-isopropylidene-α- -glucofuranose (5) was obtained in 95%
yield from commercially available
-glucose using a previously reported method.20
D-glucose in 10 steps
D
D
Then, compound 5 was oxidized with pyridinium dichromate (PDC) to give the
furan-3-ulose 6. Compound 7 was obtained via the highly stereoselective Henry
reaction,20 treated with HCO2NH4 in the presence of Pd/C and then converted to the
N-benzyloxycarbonyl (Cbz)-protected compound 8 in one pot.21 The nitro group in
compound 7 was hydrogenated using the method reported in the literature.22, 23
However, we could not identify the main thin-layer chromatography spot. Based on a
literature search,21, 24, 25 we chose Pd/C as the catalyst and HCO2NH4 as the hydrogen
source for nitro group reduction. The reduction product was used directly in the next
step, without purification.

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Selective deprotection of the 5,6-acetonide group in 8 using 75% acetic acid,26
gave triol 9 in 79% yield. Treatment of 9 with sodium metaperiodate gave the
N-protected aminoaldehyde 10 in good yield. A proton signal from the aldehyde group
was not observed in the NMR spectrum. We deduced that 10 is unstable and the
nitrogen atom may attack the aldehyde group to give a hemiacetal (Fig. 2). Compound
10 was reduced with sodium borohydride in one pot, without purification, to give the
N-protected amino alcohol 11. Removal of the 1,2-acetonide group of 11 with
trifluoroacetic acid/water and subsequent reductive aminocyclization using
ammonium formate and 5% Pd/C in methanol under reflux conditions afforded
product 1 as a thick liquid. This one-pot three-step process involves hydrogenolysis of
a N-Cbz group to give in situ formation of a primary amine, which concomitantly
undergoes reductive aminocyclization with a C1 aldehyde to give the target molecule
1.27
2.2
Biological
activity
evaluation
of
the
(3S,4S)-3-((R)-1,2-dihydroxyethyl)pyrrolidi-ne-3,4-diol (1)
Biological studies showed that the glycosidase inhibitory activity of compound
(1) was not good (IC50 ˃ 100 µM). The inhibition percentage against four
glycosidases for compound 1 at 100 µM concentration. The results are summarized in
the Table 1. In the α-glucosidase inhibition activity testing, acarbose was taken as a
positive control. The inhibition percentage of 1 mM acarbose was 56.5%. The results
showed that compound 1 had an inhibition of 45.6% at 100 µM against α-glucosidase.

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Compound 1 specific for β-glucosidase showed 34.7% inhibition activity at 100 µM,
and the inhibition activity against α-mannosidase was 27.1%. It has little significant
activity against α-galactosidase.
Scheme 1. Synthesis of (3S,4S)-3-((R)-1,2-dihydroxyethyl) pyrrolidine-3,4-diol (1)
Reagents and conditions: (a) ZnCl2, phosphoric acid, acetone; (b) PDC, Ac2O, CH2Cl2;
(c) CH3NO2, KF, THF, rt.; (d) 1) 5% Pd/C, HCO2NH4, CH3OH, reflux, 1 h and 2)
CH3OH/H2O (5:1), NaHCO3, CbzCl, 0 °C → room temperature, 2 h; (e) 75%
CH3CO2H, 55 °C, 3 h; (f) NaIO4, acetone/H2O (9:1), 0 °C, 40 min; (g) NaBH4,
THF/H2O (v/v = 4/1), 0 °C; (h) 1) TFA/H2O (3:1), 0 °C and 2) 5% Pd/C, HCO2NH4,
CH3OH, reflux, 1 h.
Fig. 2. Possible structure of aminoaldehyde 10.

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Table 1. Inhibitory potencies of compound 1
Enzyme
% inhibition a
45.6
34.7
27.1
α-glucosidase (yeast)
β-glucosidase (almond)
α-mannosidase (jack bean)
α-galactosidase (almond)
13.4
a % inhibition determined at 100 µM concentration of compound.
3. Conclusion
In conclusion, azasugar 1 was synthesized in 10 steps from commercially
available D-glucose in 24.3% overall yield. Only three column chromatography
purifications were needed in the entire synthesis. The key step was hydrogenolysis of
a N-Cbz group to give in situ formation of a primary amine with concomitant
reductive aminocyclization to give the polyhydroxylated pyrrolidine in one pot. This
method of synthesizing azasugars should be generally applicable.
4. Experimental sections
4.1 General
Melting points were measured on a WC-1 melting-point apparatus and are
uncorrected. Infrared spectra (IR) were recorded on a Bruker Vector-22 FTIR
spectrometer. Optical rotations were measured on a Perkin–Elmer 341 polarimeter
using thin film on KBr plates. NMR spectra were recorded on a Bruker advance
DPX-400 instrument and TMS as an internal standard reference. HRMS
(high-resolution mass spectra) were taken with a Q-Tof Micromass spectrometer.
Coupling constants (J) are given in Hertz (Hz). Thin-layer chromatography (TLC)

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was performed on glass plates precoated with silica gel (5–40 µm, Qingdao Marine
Chemical Factory (China)) to monitor the reactions, and 5% Pd/C was purchased
from Shanghai Chemical Factory (China). For enzyme inhibition studies substrates
were from a commercial source. α-glucosidase and α-mannosidase were purchased
from Sigma Chemicals Co. USA, and α-galactosidase and β-glucosidase were
purchased from a native reagent company (China). The substrates were purchased
from Sigma Chemicals Co. USA., namely p-nitrophenyl-α-D-glucopyranoside,
p-nitrophenyl-β-D-glucopyranoside,
p-nitrophenyl-α-D-mannopyranoside.
p-nitrophenyl-α-D-galactopyranoside
and
4.2 1,2;5,6-Di-O-isopropylidene-3-C-nitromethyl-α-D-allofuranose (7)
Compound 7 was synthesized according to the reference literature.20 White crystal,
20 = +95 (c, 1.0, CH3OH), IR(KBr)
yield: 7.8 g (63.4% from 5). m.p.: 110-112°C,
α D
[ ]
cm-1: 3362, 2988, 1560, 1377, 1080, 874. 1H NMR (400 MHz, CDCl3): δ 5.87 (d, J =
3.9 Hz, 1H ), 4.99 (d, J = 12.2 Hz, 1H ), 4.90 (d, J = 3.9 Hz, 1H ), 4.51 (d, J = 12.1 Hz,
1H ), 4.14 (dd, J = 8.5, 5.9 Hz, 1H ), 4.09–3.99 (m, 1H ), 3.96 (dd, J = 8.5, 4.8 Hz,
1H ), 3.90 (d, J = 8.6 Hz, 1H), 3.31 (s, 1H), 1.62 (s, 3H ), 1.49 (s, 3H ), 1.39 (d,
J=11.3 Hz 6H ); 13C NMR ( 100MHz, CDCl3 ): δ 113.3, 110.4, 103.7, 81.6, 79.8, 78.5,
77.0, 72.9, 67.9, 26.6, 26.5, 26.4, 25.0. HRMS: calcd for [M+Na]+: m/z 342.1163,
found: m/z 342.1165.
4.3
1,2;5,6-Di-O-isopropylidene-3-C-[[[(phenylmethoxy)carbonyl]amino]
methyl]-α-D-allofuranose (8)
To a solution of solid 7 (2.0 g, 6.3 mmol) and ammonium formate (2.0 g, 31.7
mmol) in methanol 30 mL, 5% Pd/C (0.8 g) was added and reacted at reflux

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temperature for 1 h. The catalyst was filtered through Celite and washed with CH3OH
(2 × 10 mL). H2O (10 mL) was added to the filtrate. NaHCO3 (1.58 g, 18.8 mmol)
and benzyloxy carbonyl chloride (1.56 g, 9.1 mmol) were added at 0°C. Then, the
system was stirred at r.t. for 2 h. CH3OH was removed under reduced pressure and the
residue was extracted with EtOAc (3 × 40 mL). The combined extract was washed
with brine, dried with MgSO4 and concentrated to afford a residue that was purified
by column chromatography (petroleum ether : EtOAc = 5 : 2) to give 8 as a white
α2D8
solid. 1.39 g, Yield: 76.8%. m.p.: 115-116 °C,
= +49 (c = 0.1, CHCl3), IR (KBr)
[ ]
1
cm-1: 3446, 2990, 1728, 1545, 1244, 1010, 858. H NMR (400 MHz, CDCl3): δ: 7.39
(d, J = 4.4 Hz, 5H ), 5.80 (d, J = 3.8 Hz, 1H ), 5.36 (d, J = 5.8 Hz, 1H ) 5.21 - 5.08 (m,
2H ) 4.35 (d, J = 3.8 Hz, 1H ) 4.13 (dd, J = 6.5, 3.8 Hz, 2H ) 3.93 (d, J = 2.7 Hz, 1H )
3.80 (d, J = 8.1 Hz, 1H ) 3.55 (dd, J = 13.9, 8.8 Hz, 1H ) 3.46 (dd, J = 13.9, 3.3 Hz,
13
1H ) 2.93 (s, 1H ) 1.60 (s, 3H ) 1.47 (s, 3H ) 1.37 (s, 6H ); C NMR (100MHz,
CDCl3 ): δ 156.9, 136.3, 128.6, 128.2, 128.1, 112.7, 109.9, 103.7, 81.4, 80.3, 79.4,
73.0, 68.1, 67.0, 42.0, 26.7, 26.6, 26.5, 25.2. HRMS: calcd for [M+Na]+: m/z
446.1790, found: m/z 446.1791.
4.4
1,2-O-isopropylidene-3-C-[[[(phenylmethoxy)carbonyl]amino]
methyl]-α-D-allofuranose (9)
Compound 8 (2.0 g, 4.7 mmol) was added to a solution of 75% acetate acid (20 mL)
and stirred for 2 h at 55°C. The reaction mixture was evaporated under reduced
pressure to obtain a syrup and purified by column chromatography (petroleum ether :
α2D8
acetone = 3 : 2). White solid, 1.48 g, yield: 81.9%. m.p.: 106-107 ˚C,
= +56 (c =
[ ]
1
0.1, CHCl3), IR (KBr) cm-1: 3515, 3340, 1713, 1533, 1238, 872, 700. H NMR (400
MHz, CDCl3): δ 7.41 - 7.25 (m, 5H), 5.86 - 5.61 (m, 2H), 5.18 - 4.95 (m, 2H), 4.31 (d,

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J = 3.5 Hz, 1H), 3.79 (d, J = 15.8 Hz, 3H), 3.64 (s, 1H), 3.56 - 3.34 (m, 5H), 1.53 (s,
13
3H), 1.30 (s, 3H); C NMR (100 MHz, CDCl3): δ 157.3, 136.3, 128.6, 128.2, 128.1,
112.6, 103.4, 80.2, 79.8, 79.0, 69.9, 67.1, 64.3, 42.0, 26.4, 26.3. HRMS: calcd for
[M+Na]+: m/z 406.1480, found: m/z 406.1478.
4.5 1,2-O-isopropylidene-3-C-[[[(phenylmethoxy)carbonyl]amino]
methyl]-α-D-ribofuranose (11)
To a solution of compound 9 (1.5 g, 3.9 mmol) in acetone/H2O (9:1, 15 mL),
sodium periodate (1.26 g, 5.9 mmol) was added and stirred for 40 min at 0 ˚C.
Ethylene glycol (1 mL) was added, and the acetone was removed under reduced
pressure. The residue was extracted with EtOAc (3× 30 mL). The combined extract
was washed with brine, dried with MgSO4 and concentrated to afford a syrup. To an
ice-cooled solution of the syrup in THF/H2O (v/v = 4/1, 15 mL), sodium borohydride
(0.18 g, 4.7 mmol) was added in two portions. The reaction mixture was stirred for
1.5 h, and then some NH4Cl (s) was added to terminate the reaction. THF was
evaporated under reduced pressure, extracted with EtOAc and concentrated.
Purification by column chromatography (petroleum ether : acetone = 2 : 1) to give 11
as white solid. 1.28 g, yield: 85.3%. m.p.: 114-115 ˚C,
[
αD
28 = +51 (c = 0.1, CHCl3),
]
IR(KBr) cm-1: 3455, 3343, 1716, 1547, 1243, 1003, 700. 1H NMR (400 MHz, CDCl3):
δ 7.39 - 7.31 (m, 5H), 5.81 (d, J = 3.6 Hz, 1H), 5.43 (d, J = 3.6 Hz,1H), 5.11 (q, J =
12.2 Hz, 2H), 4.31 (d, J = 3.4 Hz, 1H), 3.88 (d, J = 7.3 Hz, 2H), 3.83 - 3.72 (m, 1H),
3.48 (dd, J = 14.2, 8.5 Hz, 1H), 3.27 (dd, J = 14.4, 4.1 Hz, 1H), 3.02 (s, 1H) 2.20 (s,
13
1H) 1.56 (s, 3H), 1.34 (s, 3H); C NMR ( 100MHz, CDCl3 ): δ 157.1, 136.3, 128.6,
128.3, 128.2, 112.7, 103.6, 81.5, 80.1, 79.2, 67.1, 59.3, 41.9, 26.5, 26.4. HRMS: calcd
for [M+Na]+: m/z 376.1371, found: m/z 376.1372.

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4.6 (3S,4S)-3-((R)-1,2-Dihydroxyethyl)pyrrolidine-3,4-diol (1)
A solution of 11 (0.5 g, 1.42 mmol) in TFA/water (10 mL, 3 : 1) was stirred for 3
h at 0 °C. TFA was co-evaporated with toluene at reduced pressure to furnish a
hemiacetal as a liquid. To a solution of hemiacetal (0.45 g, 1.44 mmol) in methanol
(10 mL), 5% Pd/C (0.25 g) and ammonium formate (0.45 g, 7.14 mmol) were added,
and the reaction mixture was refluxed for 1 h. After cooling, the reaction mixture was
filtered through celite, washed with methanol, and the solvent was evaporated at
reduced pressure. Purification by column chromatography (methanol) to give 1 as an
oil. 0.16 mg, yield: 71.3%.
[
α2D8
= +9.6 (c = 0.4), IR (KBr) cm-1: 3405, 3146, 1685,
]
1401, 1208, 1139, 725. 1H NMR (400 MHz, MeOD) δ 4.20 (d, J = 3.6 Hz, 1H), 4.03
(dd, J = 6.4, 4.2 Hz, 1H), 3.83 (dd, J = 11.3, 4.2 Hz, 1H), 3.77 – 3.72 (m, 1H), 3.72 –
3.68 (m, 1H), 3.65 (dd, J = 14.9, 5.4 Hz, 1H), 3.53 (d, J = 12.1 Hz, 1H), 3.37 (d, J =
12.1 Hz, 1H), 3.33 (dt, J = 3.3, 1.6 Hz, 1H), 3.29 (d, J = 12.1 Hz, 1H).13C NMR
(100MHz, MeOD) δ 82.8, 74.4, 71.7, 62.2, 52.9, 52.7. HRMS: calcd for [M+H]+: m/z
164.0919, found: m/z 164.0923.
4.7 General procedure for α-glucosidase inhibition assay.
Inhibition rate was determined at 37 ˚C in 0.067 M K2HPO4/KH2PO4 buffer (pH
6.8). The reaction mixture contained 40 µL of enzyme solution, 40 µL of inhibitor and
20 µL of substrate. The enzymatic reaction was started after incubation of the enzyme
(0.04 U/mL) for 30 min in the presence of the inhibitor (0.1 mM) by the addition of
substrate (0.5 mM). The mixture was incubated at 37 ˚C for 5 min, and the reaction
was quenched by the addition of 0.1 M Na2CO3 (pH 9.8). The absorption at 405 nm
was measured immediately and taken as the relative rate for the hydrolysis of

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substrate. All experiments were carried out in triplicate. The IC50 value is the
concentration of inhibitor at 50% of enzyme activity18.
4.8 General procedure for β-glucosidase inhibition assay
Inhibition rate was determined at 37 ˚C in 0.08 M citric acid/Na2HPO4 buffer (pH 4.2).
The enzymatic reaction was started after incubation of the enzyme (0.02 U/mL) for
30 min in the presence of the inhibitor (0.1 mM) by the addition of substrate (5 mM).
The mixture was incubated at 37 ˚C for 5 min, and the reaction was quenched by the
addition of 0.25 M borate buffer (pH 9.8). The absorption at 405 nm was measured
immediately and taken as the relative rate for the hydrolysis of substrate18.
4.9 General procedure for α-galactosidase and α-mannosidase inhibition assay
The substrates p-nitrophenyl-α-D-galactopyranoside, of 2 mM concentration were
prepared in 0.025 M citrate buffer with pH 6.0. P-nitrophenyl-α-D-mannopyranoside
of 2 mM was prepared in 0.025 M citrate buffer with pH 4.0. The test compound was
preincubated with the respective enzyme buffered at their optimal pH for 1 h at 25 ˚C.
The enzyme reaction was initiated by the addition of 100 µL substrate. Controls were
run simultaneously in the absence of test compound. The reaction was terminated at
the end of 10 min by the addition of 0.05 M borate buffer (pH 9.8) and absorbance of
the liberated p-nitrophenol was measured at 405 nm. One unit of glycosidase activity
is defined as the amount of enzyme that hydrolyzed 1 µmol of p-nitrophenyl
pyranoside per minute at 25 ˚C.28
Acknowledgment

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We are grateful for the financial support from the National Natural Science
Foundation of China (U1204206, 81430085, 21372206).
Appendix A. Supplementary data
Supplementary data associated with this article can be found in the online version.
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ACCEPTED MANUSCRIPT
26. Yadav JS, Satyanarayana M, Raghavendra S, Balanarsaiah E. Tetrahedron Lett
2005;46:8745-48.
27. Mane RS, Kumar KA, Dhavale DD. J Org Chem 2008;73:3284-87.
28. Dhavale DD, Kumar KA, Chaudhari VD, Sharma T, Sabharwal SG,
PrakashaReddy J. Org Biomol Chem 2005;3:3720-26.

ACCEPTED MANUSCRIPT
1) A new azasugar was synthesized using one-pot reaction as a key step.
2) Our method plays an important role in the research of new azasugars.
3) The glycosidase inhibitory activity of the target molecule were not ideal.