Synthesis, molecular modeling and evaluation of α-glucosidase inhibition activity of 3,4-dihydroxy piperidines

Article abstract of DOI:10.1016/j.ejmech.2018.02.072

Biological evaluation of 3,4-dihydroxy piperidines as α-glucosidase inhibitors is being reported for the first time. Forty-five derivatives (amides, di-amides and sulfonamides) were made using cis and trans 3,4-dihydroxy piperidines to evaluate their α-glucosidase inhibition activity. Polar groups (-OH, -NH₂) on phenyl ring having derivatives 5i, 5l, 7g, 7i & 12j showed excellent activity compared to standard references. Acarbose, Voglibose and Miglitol were used as standard references. Molecular docking simulations were done for compounds to identify important binding modes responsible for inhibition activity of α-glucosidase.

Full text of DOI:10.1016/j.ejmech.2018.02.072

Accepted Manuscript
Synthesis, molecular modeling and evaluation of α-glucosidase inhibition activity of
3,4-dihydroxy piperidines
Siva Prasad Kasturi, Sujatha Surarapu, Srinivas Uppalanchi, Shubham Dwivedi,
Perumal Yogeeswari, Dilep Kumar Sigalapalli, Bathini Nagendra Babu, Krishna S.
Ethiraj, Jaya Shree Anireddy
PII:
S0223-5234(18)30209-5
10.1016/j.ejmech.2018.02.072
EJMECH 10249
DOI:
Reference:
To appear in: European Journal of Medicinal Chemistry
Received Date: 12 December 2017
Revised Date: 19 January 2018
Accepted Date: 21 February 2018
Please cite this article as: S.P. Kasturi, S. Surarapu, S. Uppalanchi, S. Dwivedi, P. Yogeeswari, D.K.
Sigalapalli, B.N. Babu, K.S. Ethiraj, J.S. Anireddy, Synthesis, molecular modeling and evaluation of α-
glucosidase inhibition activity of 3,4-dihydroxy piperidines, European Journal of Medicinal Chemistry
(2018), doi: 10.1016/j.ejmech.2018.02.072.
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to
our customers we are providing this early version of the manuscript. The manuscript will undergo
copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please
note that during the production process errors may be discovered which could affect the content, and all
legal disclaimers that apply to the journal pertain.

1
ACCEPTED MANUSCRIPT
Graphical abstract
Synthesis, molecular modeling and evaluation of α-glucosidase
inhibition activity of 3,4-dihydroxy piperidines.
Siva Prasad Kasturia,b, Sujatha Surarapua, Srinivas Uppalanchia, Shubham Dwivedic,
Yogeeswari Perumalc, Dilep Kumar Sigalapallid, Bathini Nagendra Babud, Krishna S. Ethiraja ,
Jaya Shree Anireddyb,*
aDepartment of Medicinal Chemistry, GVK Biosciences Pvt. Ltd, Plot.No.28 A, IDA, Nacharam, Hyderabad
500076, Telangana State, India
bCentre for Chemical Sciences & Technology, Institute of Science and Technology, JNTUH, Kukatpally,
Hyderabad 500085, Telangana State, India
cPharmacology Division, Drug Discovery Research Laboratory, Department of Pharmacy, Birla Institute of
Technology & Science-Pilani, Hyderabad Campus, Hyderabad 500078, Telangana State, India
dDepartment of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER),
Hyderabad 500037, Telangana State, India
Abstract: Biological evaluation of 3,4-dihydroxy piperidines as α-glucosidase inhibitors is being reported for
the first time. Forty-five derivatives (amides, di-amides and sulfonamides) were made using cis and trans 3,4-
dihydroxy piperidines to evaluate their α-glucosidase inhibition activity. Polar groups (-OH, -NH2) on phenyl
ring having derivatives 5i, 5l, 7g, 7i & 12j showed excellent activity compared to standard references.
Acarbose, Voglibose and Miglitol were used as standard references. Molecular docking simulations were done
for compounds to identify important binding modes responsible for inhibition activity of α-glucosidase.
Key words: Acarbose, Dihydroxy piperidine, α-Glucosidase inhibition, Molecular docking.
Corresponding author E-mail address: jayashreeanireddy@gmail.com

2
ACCEPTED MANUSCRIPT
1. Introduction
Diabetes mellitus is a chronic metabolic disorder, it causes various grave health complications
such as coronary artery and peripheral vascular diseases, stroke [1-3], diabetic neuropathy [4-7],
amputations [8-11], cancer [12-14], renal failure [15-16] and blindness resulting in disability [17-18],
reduced life expectancy and enormous health costs. Drastic changes in work patterns, improved
transportation, lack of physical activity, prominent modifications in lifestyle and junk foods
concomitant with globalization over the last century have resulted in an intense increase in the
incidence of diabetes worldwide. According to WHO, it will increase by more than 2.5-fold, in the
developing world from 84 million in 1995 to 228 million by 2025 [19]. Type 2 diabetes (T2DM) is the
most common form of diabetes. Though, weight control & physical activity improves glucose & lipid
metabolism and in turn decreases risk, use of one or more pharmacological agents are must in
maximum cases to manage T2DM effectively. Most of the strategies for the treatment of T2DM can
be grouped into four categories: 1) Insulin secretagogues [20-22] (trigger insulin exocytosis by
increasing intracellular calcium ion concentration) or (stimulate the beta cell to secrete insulin). 2)
Decreasing insulin resistance [23-27] (enhance insulin action which reduces hyperglycemia without
any increase in plasma insulin levels). 3) Inhibiting hepatic glucose production [28-31]. 4) Inhibiting
glucose uptake [32-36] (slowing down the absorption of dietary glucose). As diabetes is a lifelong
disorder which requires long-term medical management, extensive studies to explore more effective
and safe drugs are essential. In this therapeutic area, we have reported recently the first biological
evaluation of aza-flavanones [37] and natural product inspired scaffolds of dihydroxy pyrrolidines as
potent α-glucosidase inhibitors [38]. In continuation of our exploration, we envisaged that 3,4-
dihydroxy piperidine derivatives will show promising inhibitory activity towards
α-glucosidase
inhibition like 3,4-dihydroxy pyrrolidine derivatives. Current anti diabetic drugs having piperidine
skeleton available in clinical practice are showed in Fig.1.

3
ACCEPTED MANUSCRIPT
Fig.1. Anti-diabetic drugs having piperidine skeleton
2. Results and discussion
2.1.Chemistry
Commercially available N-Boc 3,4-dihydro piperidine was subjected for Upjohn dihydroxylation to
give the cis-diol [39] 3 (Scheme 1) and Prilezhaev reaction to give corresponding epoxide [40]
intermediate which was opened under the basic condition to give trans diol 10 (Scheme 2). Then Boc
deprotection carried out under the acidic condition to afford the required cis and trans 3,4-
dihydroxy piperidines 4 and 11 respectively (Scheme 1 & 2). Diverse chemo selective N-acylations
were successfully achieved by using uronium coupling agent HATU and the corresponding
sulfonamides were obtained by controlled sulfonation with diverse sulfonyl chlorides. Catalytic
hydrogenation was utilized to make saturated amides from their corresponding α, β-unsaturated
amides. Products were tabulated in Table 1 and 2.

4
ACCEPTED MANUSCRIPT
Table 1
Synthesized cis 3,4-dihydroxy piperidine derivatives

5
ACCEPTED MANUSCRIPT
Table 2
Synthesized trans 3,4-dihydroxy piperidine derivatives
O
R3, 4
NH
HO
R1, 2
O
HO
HO
N
HO
N
13a-f
12a-j
O
F
F
F3C
HO
F3C
HO
S
12d
12f
12e
12a
12b
12c
HO
BocHN
H2N
S
12h
F3C
12g
12i
12j
13a
13b
BocHN
H2N
HO
F3C
13d
13e
13f
13c
2.2.Biology
Forty-five compounds were made with 3,4-dihydroxy piperidines (Twenty nine from cis and
sixteen from trans) to evaluate their α-glucosidase inhibitory activity in comparison to Acarbose,
Miglitol & Voglibose as reference standards and Baker’s yeast α-glucosidase inhibitory activity was
assayed using the reported method [41-44](Please see the experimental data for method). The IC50
(best fit) were calculated using graph pad prism v 6.0 where n = 3 and results are tabulated in Table
3.
Two series of compounds (piperidine-3,4-diol and 3-(4-aminophenyl)-1-3,4-dihydroxypiperidin-1-
yl propan-1-one derivatives) were made with cis/trans 3,4-dihydroxy piperidine to compare the α-
glucosidase activities with five-membered 3,4-dihydroxy pyrrolidine series. A similar type of
analogues were chosen for comparison. No potency was observed with simple cinnamic acid (5a), no
improvement in the activity by replacing the phenyl ring either with fluoro phenyl ring (5b) or with
trifluoro methyl phenyl ring (5c). Significant improvement in biological activity was witnessed by
replacing with hydroxyl phenyl ring (5d) showing an IC50 = 442.4 µM which is close to Miglitol. To
compare the activity of aromatic compounds with hetero aromatic compounds, thiophene analogue
(5e) synthesized and tested, showed no potency in the activity.
To compare the activities of α, β-unsaturated amides with saturated amides, eight saturated
amides were synthesized by the reduction of unsaturated amides (5f-j) or by using saturated acids

6
ACCEPTED MANUSCRIPT
(5k-m) in the amidation reaction. After reduction, there is no improvement in the case of phenyl (5f)
and fluoro phenyl (5g) derivatives, but a minor improvement was observed in the case of trifluoro
methyl phenyl derivative (5h).
Table 3
α-Glucosidase enzyme inhibitory effect of 3,4-dihydroxy piperidines.
Alpha Glucosidase
inhibition IC50 (µM)
Alpha Glucosidase
inhibition IC50 (µM)
Alpha Glucosidase
inhibition IC50 (µM)
Compound No
Compound No
Compound No
7a
7b
7c
7d
7e
7f
349.2
889.5
NI
12a
12b
12c
12d
12e
12f
NI
NI
NI
NI
5a
5b
5c
5d
5e
NI
NI
667.4
NI
NI
442.4
887.6
994.4
NI
NI
478.6
284.1
NI
5f
5g
5h
422.4
7g
12g
12h
12i
742.5
151.9
NI
7h
7i
382.6
291.8
NI
662.7
5i
246.8
5j
5k
5l
12j
288.9
709.8
NI
7j
267.0
749.4
13a
8a
210.6
388.7
NI
13b
13c
13d
13e
102.96
8b
5m
6a
6b
6c
NI
8b
593.6
360.2
324.7
462.2
488.2
745.7
Acarbose
Voglibose
Miglitol
NI
464.9
384.2
13f
NI: not identified
Further improvement in the activity was observed by replacing trifluro methyl group with NHBoc
(5k), a sharp increase in the activity by replacing Boc group with H atom. The resulting amine (5l)
showed the highest activity in the first series with an IC50 = 210.6 µM, showed 2-3 fold higher activity
compared to reference standards. The considerable α-glucosidase activity with an IC50 = 291.8 µM
was exhibited by phenol derivative (5i). To compare the activities of amides with sulfonamides, three
sulfonamide analogues prepared using cis 3,4-dihydroxy piperidine. Among these sulfonamides
trifluoro methoxy derivative (6c) showed better activity.
In the second series (cis-3-(4-aminophenyl)-1-3,4-dihydroxypiperidin-1-yl propan-1-one
derivatives), among unsaturated amides except fluoro amide (7a) other amides viz., trifluoro methyl
amide (7b) and hydroxyl amide (7c) have shown negligible or no activity whereas fluoro amide (7a)
displayed considerable activity with an IC50 = 349.2 µM which is comparable to Acarbose and
Miglitol, similar pattern of inhibition activity was observed in the case of five-membered pyrrolidines
[38].
In saturated amides, fluoro amides (7e) showed zero potency, by replacing the fluoro group with
trifluoro methyl group (7f) minor improvement was observed. By replacing the trifluoro methyl

7
ACCEPTED MANUSCRIPT
group with NHBoc (7h) activity was further increased, after making the amine free (7i) activity was
doubled (IC50 = 246.8 µM) and also excellent activity was observed in the case of hydroxyl phenyl
amide (7g) with an IC50 = 284.1 µM. SAR studies clearly revealed that polar groups on the phenyl ring
are important to exhibit the α-glucosidase activity.
In the second series among all sulfonamides, trifluoromethyl phenyl sulfonamide (8b) (IC50
=
102.96 µM) showed 3-4 fold higher activity compared to standard references and identified as the
most promising active compound in this series.
We have made sixteen trans dihydroxy piperidine derivatives to compare the activities with cis
dihydroxy piperidines. Except for thiophene derivative (12h) all other trans derivatives showed less
inhibition compared to cis dihydroxy piperidines. Most active compounds were showcased in Fig.2.
NH2
OH
O
O
HN
HN
246.8 µM
284.1 µM
O
O
OH
OH
OH
OH
7g
N
N
O
7i
HN
NH2
S
210.6 µM
267.0 µM
OH
O
O
OH
OH
N
N
5l
7j
OH
Cis
OH
OH
N
H
CF3
O
Trans
S
OH
5i
8b
HN
O
291.8 µM
102.96 µM
O
O
OH
OH
N
OH
OH
N
12j
12h
O
NH2
S
O
HN
HN
151.9 µM
288.9 µM
O
O
OH
OH
N
OH
OH
N
Fig.2. Promising active compounds identified

8
ACCEPTED MANUSCRIPT
2.3.Computational methods
Molecular docking studies of corresponding dihydroxy piperidine derivatives, Acarbose, Voglibose
and Miglitol were performed by using GLIDE docking module of Schrödinger suite 2014-1. All the 3D
structures of molecules were built on Maestro Molecule Builder of Schrödinger. The built molecules
were optimized using OPLS_2005 force field in LigPrep module of Schrödinger suite. Docking
procedure was followed using the standard protocol implemented in Maestro, version 9.7 and the
molecules were docked against binding site of a 3D homology model of α-glucosidase. Each complex
of protein-ligand was analyzed for interactions and the 3D pose of the most active compound was
taken.
2.3.1. Molecular docking simulation study
The molecular docking simulation study was performed to explore the binding mode of 3, 4-
dihydroxy piperidine derivatives within the binding pocket of α-glucosidase and to understand their
interaction pattern using Glide 6.2 in Schrödinger software [45]. To perform this molecular docking
study, we have used our previously developed homology model of α-glucosidase [39]. The molecular
docking was performed by simulation of synthetic compounds into the binding site in α-glucosidase.
Table 4 demonstrates the result of the molecular docking along with hydrogen bonding as well as
arene-arene and arene-cation interactions of compounds with α-glucosidase enzyme. From this
molecular docking study, it was observed that the top-ranked conformation of the most active
compound 8b (Fig. 3) has established six hydrogen bonds with the active site residues (His109,
Arg210, Asp212, Glu274, Glu304, His348). Additionally, the oxopropyl phenyl group of the
compound formed a π - cation interaction (arene-cation interaction) with the Arg312. Furthermore,
several hydrophobic interactions were observed between the compound 8b and the active site
residues, viz., Tyr69, Phe155, Phe156, Phe175, Pro238 and Phe300 stabilizes the binding of the
compound 8b in the active site of α-glucosidase. The binding model of the compound 8b revealed
that they share some of the common interactions with the key residues of the catalytic domain as
shown by known inhibitor Acarbose. Fig. 4 shows the superimposition of known inhibitor Acarbose
and best-docked pose of compound 8b in the binding site of α-glucosidase.

9
ACCEPTED MANUSCRIPT
Fig. 3. a) Binding model of the most active compound 8b (magenta color stick) and b) its ligand-protein
interactions in the binding site of modeled α-glucosidase. The red dashed lines represent hydrogen bonds. H-
bond distances (in Å) between heteroatoms of ligand and amino acid residues are as follows: His109 (3.7),
Arg210 (2.4), Asp212 (1.5 & 1.6), Glu274 (3.7), Glu304 (1.8), His348 (2.5). The black arrow line indicates arene-
cation interaction with Arg312.
Fig. 4. Superimposition of known inhibitor Acarbose (cyan) and best-docked pose of compound 8b (magenta)
in the binding site of α-glucosidase.
Table 4
GLIDE docking results for Acarbose and some of 3, 4-dihydroxy piperidine derivatives within the
binding pocket of α-glucosidase.

10
ACCEPTED MANUSCRIPT
S.No
Ligand id
Acarbose
5i
Docking
score
Interactions
H- bonds
π - π
π -
Hydrophobic
cation
1
2
-8.41
-6.98
Phe155,
Phe156,
Glu304,
Ser308,
Gln350,
-
-
Phe155,
Phe156,
Glu274,
Thr307,
Arg312,
Asn412
Phe175,
Phe300,
Phe310,
Tyr313
Ala276,
Phe309,
Phe311,
Arg312, Asp408,
Phe155,
His237
-
-
Phe155, Phe156,
Phe175, Pro238,
Phe300, Phe311,
Tyr313
Phe 155, Phe 156, Phe
175, Phe 300, Phe 311,
Tyr 313
Asn412
3
4
5l
-7.34
-7.02
Ser154, Phe155,
Phe156, Asp349
-
7g
His109, Glu274,
Arg312, His348
His237
Arg312 Tyr69, Phe 155, Phe
156, Phe 175, Pro238,
Phe 300, Phe310,
Phe311
5
6
7i
7j
-7.29
-7.24
Arg210, Asp212,
Glu274, Glu304,
Arg312, His348
His237
His237
-
-
Tyr69, Phe155,
Phe156, Phe175,
Pro238, Phe300,
Tyr313
Tyr69, Phe155,
Phe156, Phe175,
Pro238, Phe300,
Phe311
Arg210, Asp212,
Glu274, Arg 312,
His348
-
7
8
9
8b
12h
-8.28
-7.57
-6.32
His109, Arg210,
Asp212, Glu274,
Glu304, His348
Ser154, Phe155,
Arg312
Arg312 Tyr69, Phe155,
Phe156, Phe175,
Pro238, Phe300
His237,
His243
-
-
Phe155, Pro238,
Phe310, Phe311,
Tyr313
Phe155, Phe156,
Phe175, Ala276,
Phe300, Val303,
Tyr313
Voglibose
Phe155, Phe156,
Glu304, Asp349,
Gln350, Asp408,
Asn412
-
10
Miglitol
-6.04
Phe155, Arg210,
Glu304, Asp349,
Gln350, Asp408
-
-
Phe155, Phe156,
Phe175, Phe300,
Tyr313
In case of compound 12h, it has shown three hydrogen bond interactions with the binding site
residues Ser154, Phe155, Arg312 and also shown some important hydrophobic interactions with
Phe155, Pro238, Phe310, Phe311, and Tyr313. Additionally, the thiophene moiety of this compound
established two important π - π stacking interactions (arene-arene interaction) with the His237 and
His243, respectively (Fig. 5). Similarly, Compounds 5i, 5l, 7g, 7i and 7j are also showing good docking
score and more protein-ligand interactions with the active site residues of α-glucosidase, which
made them promising active compounds in this series of synthesized molecules. Computationally it
is worthy to note that the most of the synthesized compounds showed interaction with the hydroxyl

11
ACCEPTED MANUSCRIPT
groups attached to piperidine ring of the compounds with the important active site residues. The
strong hydrogen bonding network observed for compounds 5i, 5l, 7g, 7i, 7j, 8b and 12h by the
dihydroxy functional group attached to the piperidine ring.
Compounds 5i, 5l, 7g, 7i, 7j, 8b and 12h have established ∼3, 4, 5, 4, 5, 6 and 3 stable hydrogen
bonds respectively with the binding site residues of α-glucosidase. The molecular docking simulation
study suggests that these compounds are having the good binding affinity towards the binding site
of α-glucosidase enzyme. The higher binding affinity for these compounds is presumably attributed
to the formation of the higher number of stable hydrogen bonds, arene-arene and arene-cation
interactions between the reactive group and several amino acids at the binding site.
Fig. 5. Receptor-ligand interaction diagram (2D view) of compound 12h in the binding site of modeled α-
glucosidase. Amino acid residues within 4.0Å of the ligand are presented in the two-dimensional interaction
diagram. The pink lines represent hydrogen bonding and green lines represent π - π stacking.
2.3.2. Prime MM/GBSA binding energy calculations
MM/GBSA (Molecular mechanics with generalized born surface area) is one of the most
frequently employed computational methods to estimate relative binding affinities of target protein-
ligand complexes. The MM/GBSA analysis was used to calculate ligand-binding energies based on
docking complex, using the MM/GBSA technology available in Prime module of Schrodinger 2014-1.
The protein-ligand complexes obtained from the docking studies were subjected to MM/GBSA
calculations. The relative binding free energy ΔGbind was estimated according to the following
equation:
ΔGbind = Ecomplex (minimized) - [Eligand (unbound, minimized) +
Ereceptor (unbound, minimized)]

12
ACCEPTED MANUSCRIPT
Where ΔGbind is the calculated relative free energy which includes both ligand and receptor strain
energy. Ecomplex (minimized) is the MM/GBSA energy of the minimized complex, and Eligand (unbound,
minimized) is the MM/GBSA energy of the ligand after removing it from the complex and allowing it
to relax. Ereceptor (unbound, minimized) is the MM/GBSA energy of protein after separating it from the
ligand.
Table 5
Binding energies (ΔGbind) obtained for some of synthesized 3, 4-dihydroxy piperidine derivatives and
other known α-glucosidase inhibitors.
Binding energy
S.No
Ligand id
(kcal/mol)
1
2
5i
-32.204
-38.046
-39.096
-46.439
-39.299
-48.947
-48.017
-39.342
-42.027
-82.208
5l
7g
3
4
7i
5
7j
6
8b
7
12h
8
Voglibose
Miglitol
Acarbose
9
10
MM/GBSA calculations were performed for best ranking molecules in SP mode of molecular
docking. MM/GBSA and docking protocols employed in the present work for assessing ligand
affinities to α-glucosidase enzyme, therefore it gives more reliable understanding of enzyme
inhibition activity of synthesized 3, 4-dihydroxy piperidine derivatives. The list of some inhibitors
along with their ΔGbind energy values from Prime have been tabulated in Table 5. In this study, the
analogues showed binding energies comparable to that of known α-glucosidase enzyme inhibitors.
However, some of the identified ligands showed more binding energy values than that of the known
inhibitors (Miglitol & Voglibose), suggesting stronger binding and the formation of more stable
ligand-protein complexes (Table 5).

13
ACCEPTED MANUSCRIPT
2.3.3. ADME & Toxicity studies
ADME/T properties were calculated using Qikprop module of Schrodinger 2014-1. It predicts both
physicochemically significant descriptors and pharmacokinetically significant properties. QikProp
provides comparative ranges of molecule’s properties with those of known drugs. Schrodinger
software, among which major parameters reported here are required for predicting the ADME/T of
molecules, and other in silico parameters (carcinogenicity & LogP) were predicted using PreADMET
[46] and Molinspiration online property calculation toolkit [47] and the results were presented in
Table 6. From these studies, we are able to quickly compare the ADME/T properties of the
synthesized 3, 4-dihydroxy piperidine derivatives with that of known α-glucosidase enzyme
inhibitors.
The recommended ranges for some of the computed ADME/T parameters showed in Table 6
were mentioned below.
1.
2.
3.
4.
5.
6.
Predicted central nervous system activity (CNS) on a –2 (inactive) to +2 (active) scale
Predicted apparent Caco-2 cell permeability (QPPCaco) in nm/sec (<25 poor, >500 great)
Predicted brain/blood partition coefficient (QPlogBB) (–3.0 – 1.2)
Predicted skin permeability (QPlogKp) (–8.0 – –1.0)
PM3 calculated ionization potential (IP(ev)†) (7.9 – 10.5)
Predicted human oral absorption on 0 to 100% scale (>80% is high <25% is poor)
Some of the synthesized 3, 4-dihydroxy piperidine derivatives showed significant values for the
properties analyzed (Table 6) and exhibited drug-like characteristics based on Lipinski’s rule. All the
ligands have appropriate logP value for biological efficacy and no ligand is showing carcinogenic
effect. The other associated factor, such as blood brain permeability also in the acceptable range of
all the synthesized molecules. All these insilico parameters of synthesized 3, 4-dihydroxy piperidine
compounds are within the acceptable range defined for human use. In addition, the marketed drugs
such as Acarbose and Voglibose are associated with bioavailability issues such as poor oral
absorption, but our synthesized 3, 4-dihydroxy piperidine compounds are showing good percent
human oral absorption. Thus, from these studies we observed that the synthesized 3, 4-dihydroxy
piperidine derivatives are having good drug likeliness and ADME property.

ACCEPTED MANUSCRIPT
14
Table 6
ADME/T Profile of some of the synthesized 3, 4-dihydroxy piperidine compounds and other known α-glucosidase inhibitors.
Parameters
Predicted
Predicted
Predicted
CNS
Activity
apparent
Caco-2 cell
permeability
in nm/sec.
Rule_of_ LogP Carcino_ Carcino_
Rat
brain/blood Predicted skin
permeability
Ionization
Potential
Percent Human
Oral Absorption
Ligand Id
Five
Mouse
partition
coefficient
-0.02
-0.46
5i
5l
Suitable
Suitable
negative negative
negative negative
-2
-2
131.924
113.109
-1.429
-1.499
-3.640
-3.783
9.033
8.044
65.750
63.584
7g
7i
Suitable
Suitable
Suitable
1.48
1.04
negative negative
negative negative
negative negative
-2
-2
-2
46.939
40.308
153.585
-2.613
-2.705
-1.512
-3.639
-3.777
-3.047
8.900
8.124
8.912
66.111
63.839
75.059
7j
0.94
2.12
8b
Suitable
Suitable
negative negative
negative negative
-2
-1
59.429
-1.970
-0.763
-3.869
-2.977
9.005
9.561
70.172
12h
0.05
370.888
77.235
14.069 (Slowly
and poorly
absorbed)
-3.98
Voglibose
Miglitol
Violated
Suitable
Violated
negative negative
negative negative
negative negative
-2
-2
-2
8.582
34.023
0.087
-1.872
-1.005
-5.267
-7.209
-6.431
-10.093
8.743
8.537
8.942
-2.79
-5.51
41.505
0.000
(Extremely low
bioavailability)
Acarbose

15
ACCEPTED MANUSCRIPT
3. Conclusions
In conclusion, two series of novel 3,4-dihydroxypiperidine compounds were synthesized and
evaluated their α-glucosidase inhibitory activity. Compounds 5i, 5l, 7g, 7i, 7j, 8b, 12h and 12j have
exhibited excellent α-glucosidase inhibitory activity. Polar –OH or –NH2 groups on phenyl ring has a
high impact on the potency of the compounds and further structural modification of these active
derivatives may lead to a potent anti-diabetic candidate molecule and further work in this area is in
progress.
4. Experimental section
4.1.Chemistry
Melting points were determined in capillaries, recorded on Buchi Melting Point B-540 and are
uncorrected. 1H and 13CNMR spectra were recorded on Varian 400 MHz and 300 MHz spectrometers,
using CDCl3 and DMSO-d6 as solvents. Chemical shifts are given in ppm with TMS as an internal
reference. J values are given in Hertz. Reactions were monitored by thin-layer chromatography (TLC)
coated with Silica Gel. Column chromatography was performed with 100-200 mesh silica.
tert-Butyl 5,6-dihydropyridine-1(2H)-carboxylate (2):
Na2CO3 (3.0 mol) and di-tert-butyl dicarbonate (1.1 mol) were added sequentially to solution of
1,2,3,6-tetrahydropyridine (1.0 mol) in 1, 4-dioxane and water (1:1, 10 v) at 0 °C. The reaction
mixture was slowly allowed to RT, stirred for 6 h. The reaction mixture was diluted with EtOAc (50 v)
and washed with water (50 v) and saturated brine solution (50 v), dried over Na2SO4 and
concentrated in reduced pressure to get the crude compound. The crude compound was purified on
1
a silica gel column using ethyl acetate in hexane yielding title compound as a liquid in 92% yield. H
NMR (400 MHz, CDCl3): δ 5.85-5.78 (br s, 1H), 5.68-5.62 (br s, 1H), 3.87 (s, 2H), 3.48 (t, J = 5.2 Hz,
2H), 2.12 (s, 2H), 1.47 (s, 9H); 13C NMR (100 MHz, CDCl3): δ 154.96, 125.18, 124.46, 79.37, 43.48,
39.60, 28.17, 25.11; LC-MS (ESI) m/z Calcd. for C10H17NO2: 183.13, Found: 184.17 [M+H]+.
cis-tert-Butyl 3,4-dihydroxypiperidine-1-carboxylate (3):
tert-Butyl 5,6-dihydropyridine-1(2H)-carboxylate (2) (1 mol) was added to a solution of potassium
osmate (0.1 mol) and NMO (2 mol) in THF and H2O (4:1; 10 v). The reaction mixture was stirred at RT
for 16 h and a solution of saturated sodium metabisulfite (10 v) was added to quench the excess
oxidant. The reaction mixture was diluted with water (40 v) and extracted with EtOAc (2 x 20 v). The
combined organic layers were washed with saturated brine solution, dried over Na2SO4 and
evaporated under vacuo. Purification was done by flash column chromatography using EtOAc in
hexane, afforded the desired product as a clear liquid in 88% yield. 1H NMR (400 MHz, CDCl3): δ 3.84
(br s, 1H), 3.75 (br s, 1H), 3.56-3.50 (m, 2H), 3.41 (dd, J = 13.2, 3.6 Hz, 1H), 3.28-3.22 (m, 1H), 1.84-

16
ACCEPTED MANUSCRIPT
1.76 (m, 1H), 1.70-1.63 (m, 1H), 1.44 (s, 9H); 13C NMR (100 MHz, CDCl3): δ 155.35, 79.96, 68.43,
67.91, 45.66, 40.17, 29.51, 28.32; LC-MS (ESI) m/z Calcd. for C10H19NO4: 217.13, Found: 216.06 [M-H]-
tert-Butyl 7-oxa-3-azabicyclo[4.1.0]heptane-3-carboxylate (9):
To a solution of m-CPBA (2 mmol) in DCM (8 v) was added tert-butyl 5,6-dihydropyridine-1(2H)-
carboxylate (1 mmol) in DCM (2 v) drop-wise at 0 °C. The reaction mixture was stirred at rt for 14 h,
then filtered. The filter cake was washed with DCM (10 v x 2) and the combined filtrates were
washed with saturated aqueous Na2CO3 (300 mL x 2). The solution was dried over anhydrous Na2S04,
concentrated in vacuo and purified by a silica gel column chromatography to give the title compound
as colorless oil in 93% yield. 1H NMR (400 MHz, DMSO-d6): δ 3.60 (s, 2H), 3.29-3.10 (m, 4H), 1.88-
1.81 (m, 2H), 1.38 (s, 9H); 13C NMR (100 MHz, DMSO-d6): δ 154.02, 78.69, 49.68 & 49.32, 47.27 &
41.67, 37.91, 36.68, 27.96, 23.42; LC-MS (ESI) m/z Calcd. for C10H17NO3: 199.12, Found: 144.32 [M-
tBu]+.
trans-tert-Butyl 3,4-dihydroxypiperidine-1-carboxylate (10):
2M solution of KOH (2 mmol) was added to
a
solution of tert-butyl 7-oxa-3-
azabicyclo[4.1.0]heptane-3-carboxylate (1 mmol) in 1,4-dioxane (10 v), the reaction mixture was
stirred at 80 °C for 8 h. The reaction mixture was diluted with water (50 v) and extracted with ethyl
acetate (50 v x 2). The combined organic layer was washed with saturated brine solution (30 v),
dried over anhydrous sodium sulphate and evaporated under reduced pressure to give crude
compound. Purification was done by flash column chromatography using EtOAc in hexane, afforded
desired product as a clear liquid in 86% yield. 1H NMR (400 MHz, CDCl3): δ 4.17-4.11 (m, 1H), 4.00 (br
s, 1H), 3.54-3.48 (m, 1H), 3.45-3.39 (m, 1H), 2.80 (br s, 2H), 2.66-2.61 (m, 1H), 1.97-1.91 (m, 1H),
1.51-1.45 (m, 9H); 13C NMR (100 MHz, CDCl3): δ 154.85, 80.18, 73.67, 71.93, 47.70, 42.26, 31.53,
28.37; LC-MS (ESI) m/z Calcd. for C10H19NO4: 217.13, Found: 218.12 [M+H]+.
General procedure for the preparation of compounds 4, 5l, 7i, 11, 12j and 13f
A solution of 4M HCl in dioxane (3 mol) was added to the solution of Boc-compound (1 mol) in DCM
(10 v) under the nitrogen atmosphere at 0 °C. The reaction mixture was slowly warmed to RT &
stirred for 4 h. The reaction mixture was evaporated under reduced pressure, diethyl ether (20 v)
was added to the residue and stirred for 10 min. The organic layer was decanted and dried to get
pure compounds 4, 5l, 7i, 11, 12j and 13f as solids in 89-96% yields.
cis-Piperidine-3,4-diol hydrochloride (4):
1
Yield: 95.0%; Hygroscopic; H NMR (400 MHz, DMSO-d6): δ 5.06 (br s, 2H), 3.81-3.72 (m, 2H), 2.98-
2.85 (m, 4H), 1.86-1.69 (m, 2H); 13C NMR (100 MHz, DMSO-d6): δ 65.68, 65.30, 44.94, 26.61; LC-MS
(ESI) m/z Calcd. for C5H11NO2: 117.08, Found: 118.10 [M+H]+.

17
ACCEPTED MANUSCRIPT
3-(4-Aminophenyl)-1-(cis-3,4-dihydroxypiperidin-1-yl)propan-1-one hydrochloride (5l):
Yield: 92.0%; Hygroscopic; 1H NMR (400 MHz, DMSO-d6): δ 7.28-7.15 (m, 4H), 4.62-4.46 (m, 2H, OH),
3.70-3.60 (m, 2H), 3.52-3.48 (m, 1H), 3.36-3.30 (m, 1H), 3.21-3.05 (m, 2H), 2.81-2.77 (m, 2H), 2.63-
2.59 (m, 2H), 1.64-1.40 (m, 2H); 13C NMR (100 MHz, DMSO-d6): δ 170.26 & 169.84, 141.54 & 141.42,
128.30, 128.24 & 128.13, 125.69, 68.07 & 67.74, 67.57 & 67.19, 48.07, 43.13 & 38.11, 34.05 & 33.97,
30.81 & 30.73, 30.35 & 29.05; LC-MS (ESI) m/z Calcd. for C14H20N2O3: 264.15, Found: 265.10 [M+H]+.
3-(4-Aminophenyl)-N-(4-(3-(cis-3,4-dihydroxypiperidin-1-yl)-3-oxopropyl)phenyl)propanamide
hydrochloride (7i):
1
Yield: 90%; MR: 181-185 °C; H NMR (400 MHz, DMSO-d6): δ 10.23 (br s, 2H, NH2), 9.93 (s, 1H, NH),
7.46 (d, J = 8.0 Hz, 2H), 7.36 (d, J = 8.0 Hz, 2H), 7.29 (d, J = 8.0 Hz, 2H), 7.13 (d, J = 8.4 Hz, 2H), 3.71-
3.62 (m, 2H), 3.52-3.48 (m, 2H), 3.37-3.30 (m, 1H), 3.21-3.15 (m, 1H), 2.92 (t, J = 7.2 Hz, 2H), 2.72 (t, J
= 7.2 Hz, 2H), 2.63-2.55 (m, 4H), 1.65-1.41 (m, 2H); 13C NMR (100 MHz, DMSO-d6): δ 170.35, 169.92,
141.26, 137.04, 136.19, 129.65, 129.52, 128.49 & 128.43, 123.06, 119.07, 68.14 & 67.81, 67.65 &
67.24, 48.14, 43.17, 38.18, 37.62, 34.21 & 34.10, 30.57 & 30.28, 29.09; LC-MS (ESI) m/z Calcd. for
C23H29N3O4: 411.24, Found: 412.22 [M+H]+.
trans-Piperidine-3,4-diol hydrochloride (11):
Yield: 96.0%; Hygroscopic; 1H NMR (400 MHz, DMSO-d6): δ 9.01 (br s, 1H), 8.54 (br s, 1H), 5.50 (br s,
2H), 3.60-3.39 (m, 2H), 3.10-3.01 (m, 2H), 2.89-2.86 (m, 1H), 2.79-2.76 (m, 1H), 2.01-1.94 (m, 1H),
1.58-1.50 (m, 1H); 13C NMR (100 MHz, DMSO-d6): δ 66.69, 66.55, 45.13, 26.33; LC-MS (ESI) m/z
Calcd. for C5H11NO2: 117.08, Found: 118.06 [M+H]+.
3-(4-Aminophenyl)-1-(trans-3,4-dihydroxypiperidin-1-yl)propan-1-one hydrochloride (12j):
1
Yield: 90.0%; Hygroscopic; H NMR (400 MHz, DMSO-d6): δ 10.28 (br s, 3H), 7.35 (d, J = 8.4 Hz, 2H),
7.28 (d, J = 8.0 Hz, 2H), 4.04-3.52 (m, 3H), 3.44-3.03 (m, 3H), 2.82 (t, J = 7.2 Hz, 2H), 2.68-2.59 (m,
2H), 1.79-1.71 (m, 1H), 1.25-1.20 (m, 1H); 13C NMR (100 MHz, DMSO-d6): δ 169.77 & 169.53, 141.70
& 141.59, 129.54, 129.35, 122.95, 71.28 & 70.40, 69.87 & 69.61, 48.01 & 45.19, 42.40 & 37.98,
33.60, 30.09, 29.82; LC-MS (ESI) m/z Calcd. for C14H20N2O3: 264.15, Found: 265.0 [M+H]+.
3-(4-Aminophenyl)-N-(4-(3-(trans-3,4-dihydroxypiperidin-1-yl)-3-oxopropyl)phenyl)propanamide
hydrochloride (13f):
Yield: 89%; MR: Hygroscopic; 1H NMR (400 MHz, DMSO-d6): δ 10.23 (br s, 2H, NH2), 9.78 (s, 1H, NH),
7.45 (d, J = 8.0 Hz, 2H), 7.12 (d, J = 8.0 Hz, 2H), 6.87 (d, J = 8.4 Hz, 2H), 6.47 (d, J = 8.4 Hz, 2H), 4.93-
4.91 (m, 1H), 4.79 (br s, 3H), 4.04-3.43 (m, 3H), 3.33-3.02 (m, 3H), 2.74-2.49 (m, 8H), 1.77-1.74 (m,
1H), 1.25-1.20 (m, 1H); 13C NMR (100 MHz, DMSO-d6): δ 170.39, 170.01 & 169.79, 146.52, 137.10,
136.00 & 135.89, 128.50, 128.36, 128.03, 119.01, 113.91, 71.33 & 70.41, 69.92 & 69.68, 48.19 &

18
ACCEPTED MANUSCRIPT
45.20, 42.47 & 38.57, 37.96, 37.03, 31.82, 30.19, 29.88; LC-MS (ESI) m/z Calcd. for C23H29N3O4:
411.24, Found: 412.36 [M+H]+.
General procedure for the preparation of compounds 5a-e, 5k, 5m, 7a-d, 7h, 7j, 12a-d, 12i, 13a-b
and 13e
DIPEA (3 mol), HATU (1.5 mol) were added sequentially to a stirred solution of acid (1.1 mol) in
DMF (10 v). After 5 min, corresponding amine (1.0 mol) was added and stirred at RT under argon
atmosphere for 16 h. After completion of the reaction, the reaction mixture was diluted with water
(50 v), extracted with EtOAc (50 v X 2) and evaporated the solvent in vacuo to get the crude product.
The crude product was purified by column chromatography using silica gel to afford 5a-e, 5k, 5m,
7a-d, 7h, 7j, 12a-d, 12i, 13a-b and 13e as liquids/solids in 55-87% yield.
(E)-1-(cis-3,4-Dihydroxypiperidin-1-yl)-3-phenylprop-2-en-1-one (5a):
Yield: 81.0%; MR: 152-154 °C; 1H NMR (400 MHz, DMSO-d6): δ 7.74-7.62 (m, 2H), 7.45-7.34 (m, 4H,),
7.22 (t, J = 8.80 Hz, 1H), 4.54-4.48 (br s, 2H, OH), 3.79-3.59 (m, 4H), 3.46-3.19 (m, 2H), 1.76-1.48 (m,
2H); 13C NMR (100 MHz, DMSO-d6): δ 164.99 & 164.54, 141.07 & 140.60, 135.22, 129.25, 128.65,
127.85 & 127.76, 118.92 & 118.64, 68.13 & 67.94, 67.71 & 67.35, 48.25, 43.81, 30.95 & 29.18; LC-MS
(ESI) m/z Calcd. for C14H17NO3: 247.12, Found: 248.15 [M+H]+.
(E)-1-(cis-3,4-Dihydroxypiperidin-1-yl)-3-(4-fluorophenyl)prop-2-en-1-one (5b):
Yield: 78.0%; MR: 194-197 °C; 1H NMR (400 MHz, DMSO-d6): δ 7.80-7.75 (m, 2H), 7.43 (dd, J = 15.2,
6.8 Hz, 1H), 7.25-7.16 (m, 3H), 4.74-4.58 (m, 2H, OH), 3.80-3.52 (m, 4H), 3.45-3.17 (m, 2H), 1.72-1.48
(m, 2H); 13C NMR (100 MHz, DMSO-d6): δ 169.99, 162.36, 138.61, 129.81 & 129.72, 128.55, 119.19,
116.02 & 115.80, 74.63, 73.09, 52.02, 51.32, 29.70; LC-MS (ESI) m/z Calcd. for C14H16FNO3: 265.11,
Found: 266.20 [M+H]+.
(E)-1-(cis-3,4-Dihydroxypiperidin-1-yl)-3-(4-(trifluoromethyl) phenyl)prop-2-en-1-one (5c):
Yield: 67.0%; MR: 148-150 °C; 1H NMR (400 MHz, DMSO-d6): δ 7.92 (t, J = 7.2 Hz, 2H), 7.74 (d, J = 8.8
Hz, 2H), 7.50 (dd, J = 15.6, 4.8 Hz, 1H), 7.38 (t, J = 16.4 Hz, 1H), 4.71-4.55 (m, 2H, OH), 3.86-3.60 (m,
4H), 3.47-3.23 (m, 2H), 1.77-1.48 (m, 2H); 13C NMR (100 MHz, DMSO-d6): δ 164.62 & 164.13, 139.25,
138.78, 129.17 & 128.85, 128.48 & 128.39, 125.44, 122.73, 121.97 & 121.72, 68.13 & 67.91, 67.69 &
67.33, 48.34, 43.89, 30.91 & 29.11; LC-MS (ESI) m/z Calcd. for C15H16F3NO3: 315.11, Found: 316.03
[M+H]+.
(E)-1-(cis-3,4-Dihydroxypiperidin-1-yl)-3-(4-hydroxyphenyl)prop-2-en-1-one (5d):
1
Yield: 68.0%; MR: 201-204 °C; H NMR (400 MHz, DMSO-d6): δ 8.31 (s, 1H, OH), 7.47 (d, J = 7.2 Hz,
2H), 7.34 (d, J = 14.4 Hz, 1H), 6.95-6.91 (m, 1H), 6.71 (d, J = 8.0 Hz, 2H), 3.73-3.32 (m, 6H), 1.72-1.48
(m, 2H); LC-MS (ESI) m/z Calcd. for C14H17NO4: 263.12, Found: 264.17 [M+H]+.

19
ACCEPTED MANUSCRIPT
(E)-1-(cis-3,4-Dihydroxypiperidin-1-yl)-3-(thiophen-3-yl)prop-2-en-1-one (5e):
Yield: 75.0%; MR: 205-209 °C; 1H NMR (400 MHz, DMSO-d6): δ 7.83 (s, 1H), 7.58 (s, 2H), 7.46 (dd, J =
15.2, 6.4 Hz, 1H), 7.06 (t, J = 14.4 Hz, 1H), 4.74-4.58 (m, 2H, OH), 3.77-3.57 (m, 4H), 3.45-3.35 (m,
1H), 3.28-3.15 (m, 1H), 1.68-1.45 (m, 2H); 13C NMR (100 MHz, DMSO-d6): δ 165.26 & 164.79, 138.49,
135.36, 134.92, 127.52 & 127.23, 126.04 & 125.96, 118.23 & 117.92, 68.19 & 68.01, 67.75 & 67.39,
48.18, 43.85, 31.03 & 29.24; LC-MS (ESI) m/z Calcd. for C12H15NO3S: 253.08, Found: 254.17 [M+H]+.
tert-Butyl 4-(3-(cis-3,4-dihydroxypiperidin-1-yl)-3-oxopropyl) phenylcarbamate (5k):
Yield: 76.0%; MR: 70-73 °C; 1H NMR (400 MHz, DMSO-d6): δ 9.16 (s, 1H, NH), 7.32 (d, J = 8.0 Hz, 2H),
7.09 (d, J = 8.4 Hz, 2H), 4.62-4.46 (m, 2H, OH), 3.73-3.04 (m, 6H), 2.71 (t, J = 7.2 Hz, 2H), 2.58-2.52
(m, 2H), 1.65-1.39 (m, 11H); 13C NMR (100 MHz, DMSO-d6): δ 170.33 & 169.92, 152.74, 137.26,
135.06 & 134.94, 128.38 & 128.33, 118.12, 78.72, 68.07 & 67.74, 67.58 & 67.21, 48.09, 43.13, 38.08,
34.23 & 34.12, 30.08 & 29.06, 28.09; LC-MS (ESI) m/z Calcd. for C19H28N2O5: 364.20, Found: 365.12
[M+H]+.
(cis-3,4-Dihydroxypiperidin-1-yl)(1-methyl-1H-indol-2-yl)methanone (5m):
1
Yield: 72.0%; MR: 118-122 °C; H NMR (400 MHz, DMSO-d6): δ 7.58 (d, J = 7.60 Hz, 1H), 7.48 (d, J =
7.60 Hz, 1H), 7.22 (d, J = 8.0 Hz, 1H), 7.08 (d, J = 7.20 Hz, 1H), 6.61 (s, 1H), 4.72-4.62 (m, 2H, OH),
4.02-3.45 (m, 6H), 3.55-3.42 (m, 2H), 1.78-1.53 (m, 2H); 13C NMR (100 MHz, DMSO-d6): δ 162.22,
137.07, 132.92, 126.00, 122.45, 120.96, 119.74, 110.10, 101.86, 67.61, 45.38, 35.70, 30.65, 28.67;
LC-MS (ESI) m/z Calcd. for C15H18N2O3: 274.13, Found: 275.07 [M+H]+.
(E)-N-(4-(3-(cis-3,4-Dihydroxypiperidin-1-yl)-3-oxopropyl)phenyl)-3-(4-fluorophenyl)acrylamide
(7a):
Yield: 67.0%; MR: 164-167 °C; 1H NMR (400 MHz, CDCl3): δ 7.71-7.61 (m, 2H), 7.49 (t, J = 8.0 Hz, 2H),
7.41 (d, J = 7.2 Hz, 1H), 7.17 (t, J = 7.6 Hz, 2H), 7.06 (t, J = 8.4 Hz, 2H), 6.49 (d, J = 15.6 Hz, 1H), 3.84-
3.75 (m, 2H), 3.62-3.60 (m, 1H), 3.50-3.47 (m, 1H), 3.27-3.19 (m, 2H), 2.95-2.91 (m, 2H), 2.66-2.62
(m, 2H), 1.75-1.57 (m, 2H); LC-MS (ESI) m/z Calcd. for C23H25FN2O4: 412.45, Found: 413.09 [M+H]+.
(E)-N-(4-(3-(cis-3,4-Dihydroxypiperidin-1-yl)-3-oxopropyl)phenyl)-3-(4-(trifluoromethyl)phenyl)
acrylamide (7b):
1
Yield: 62.0%; MR: 88-91 °C; H NMR (400 MHz, DMSO-d6): δ 10.24 (s, 1H, NH), 7.85-7.79 (m, 4H),
7.66-7.59 (m, 3H), 7.20 (d, J = 8.4 Hz, 2H), 6.95 (d, J = 15.6 Hz, 1H), 4.68-4.52 (m, 2H, OH), 3.74-3.63
(m, 2H), 3.54-3.49 (m, 1H), 3.34 (s, 1H), 3.22-3.17 (m, 1H), 3.10-3.07 (m, 1H), 2.78-2.75 (m, 2H), 2.62-
2.56 (m, 2H), 1.61-1.55 (m, 1H), 1.45-1.40 (m, 1H); 13C NMR (100 MHz, DMSO-d6): δ 170.33, 169.90,
162.81, 138.84, 138.16, 136.92, 136.85, 129.02, 128.65, 128.29, 125.85, 125.19, 119.25, 68.13 &
67.79, 67.63 & 67.24, 48.15, 43.18, 38.18, 34.08, 30.25 & 29.06; LC-MS (ESI) m/z Calcd. for
C24H25F3N2O4: 462.18, Found: 463.21 [M+H]+.

20
ACCEPTED MANUSCRIPT
(E)-N-(4-(3-(cis-3,4-Dihydroxypiperidin-1-yl)-3-oxopropyl)phenyl)-3-(4-hydroxyphenyl)acrylamide
(7c):
1
Yield: 55.0%; MR: 228-230 °C; H NMR (400 MHz, DMSO-d6): δ 10.00 (s, 1H, NH), 7.57 (d, J = 8.4 Hz,
2H), 7.48-7.44 (m, 3H), 7.17 (d, J = 8.4 Hz, 2H), 6.82 (d, J = 8.0 Hz, 2H), 6.60 (d, J = 16.0 Hz, 1H), 4.67-
4.51 (m, 2H, OH), 3.74-3.63 (m, 2H), 3.53-3.49 (m, 1H), 3.32-3.17 (m, 2H), 3.09-3.05 (m, 1H), 2.76-
2.73 (m, 2H), 2.61-2.59 (m, 2H), 1.64-1.54 (m, 1H), 1.46-1.42 (m, 1H); 13C NMR (100 MHz, DMSO-d6):
δ 170.36 & 169.93, 163.81, 159.12, 140.09, 137.32, 136.32 & 136.19, 129.45, 128.61 & 128.55,
125.75, 119.08, 118.67, 115.82, 68.13 & 67.79, 67.63 & 67.24, 48.15, 43.18, 38.18, 34.23 & 34.13,
30.25 & 29.10; LC-MS (ESI) m/z Calcd. for C23H26N2O5: 410.18, Found: 411.21 [M+H]+.
(E)-N-(4-(3-(cis-3,4-Dihydroxypiperidin-1-yl)-3-oxopropyl)phenyl)-3-(thiophen-3-yl)acrylamide (7d):
1
Yield: 59.0%; MR 215-218 °C; H NMR (400 MHz, DMSO-d6): δ 10.06 (s, 1H, NH), 7.86 (s, 1H), 7.64-
7.55 (m, 4H), 7.37 (d, J = 4.8 Hz, 1H), 7.17 (d, J = 8.0 Hz, 2H), 6.63 (d, J = 16.0 Hz, 1H), 4.67-4.51 (m,
2H, OH), 3.70-3.63 (m, 2H), 3.53-3.50 (m, 1H), 3.41-3.31 (m, 1H), 3.22-3.17 (m, 1H), 3.10-3.09 (m,
1H), 2.75-2.74 (m, 2H), 2.59-2.57 (m, 2H), 1.52-1.42 (m, 2H); LC-MS (ESI) m/z Calcd. for C21H24N2O4S:
400.15, Found: 411.21 [M+H]+.
tert-Butyl
4-(3-(4-(3-(cis-3,4-dihydroxypiperidin-1-yl)-3-oxopropyl)phenylamino)-3-oxopropyl)
phenylcarbamate (7h):
Yield: 78.0%; MR: 140-144 °C; 1H NMR (400 MHz, DMSO-d6): δ 9.76 (s, 1H, NH), 9.18 (s, 1H, NH), 7.45
(d, J = 8.4 Hz, 2H), 7.34 (d, J = 8.4 Hz, 2H), 7.11 (t, J = 8.8 Hz, 4H), 4.60-4.52 (m, 2H, OH), 3.70-3.52 (m,
3H), 3.32-3.30 (m, 1H), 3.21-3.18 (m, 1H), 3.12-3.06 (m, 1H), 2.81 (t, J = 7.2 Hz, 2H), 2.73 (t, J = 7.2 Hz,
2H), 2.58-2.49 (m, 4H), 1.65-1.52 (m, 2H), 1.45 (s, 9H); 13C NMR (100 MHz, DMSO-d6): δ 170.28,
170.10, 169.86, 152.72, 137.37, 137.01, 136.10, 134.63, 128.35 & 128.25, 119.02, 118.13, 78.74,
68.06 & 67.73, 67.57 & 67.19, 48.07, 43.13, 38.05, 34.16 & 34.05, 30.51, 30.20, 29.05, 28.07; LC-MS
(ESI) m/z Calcd. for C28H37N3O6: 511.27, Found: 512.13 [M+H]+.
N-(4-(3-(cis-3,4-Dihydroxypiperidin-1-yl)-3-oxopropyl)phenyl) thiophene-3-carboxamide (7j):
1
Yield: 87.0%; Thick liquid H NMR (400 MHz, DMSO-d6): δ 9.95 (s, 1H, NH), 8.32-8.31 (m, 1H), 7.65-
7.61 (m, 4H), 7.20 (d, J = 8.4 Hz, 2H), 4.61-4.54 (m, 2H, OH), 3.72-3.63 (m, 2H), 3.54-3.51 (m, 1H),
3.37-3.32 (m, 1H), 3.23-3.08 (m, 1H), 3.00-2.80 (m, 1H), 2.77-2.63 (m, 2H), 2.61-2.57 (m, 2H), 1.71-
1.52 (m, 1H), 1.46-1.42 (m, 1H); 13C NMR (100 MHz, DMSO-d6): δ 170.31 & 169.90, 160.64, 137.84,
136.76, 136.62, 129.32, 128.40 & 128.34, 127.11, 126.75, 120.28, 68.08 & 67.76, 67.59 & 67.21,
48.10, 43.16, 34.13 & 34.03, 30.53 & 30.28, 29.05; LC-MS (ESI) m/z Calcd. for C19H22N2O4S: 374.13,
Found: 375.17 [M+H]+.

21
ACCEPTED MANUSCRIPT
(E)-1-(trans-3,4-Dihydroxypiperidin-1-yl)-3-(4-fluorophenyl)prop-2-en-1-one (12a):
Yield: 81.0%; Liquid 1H NMR (400 MHz, D2O): δ 7.75 (br s, 2H), 7.44 (d, J = 14.8 Hz, 1H), 7.25-7.14 (m,
3H), 4.13-3.61 (m, 3H), 3.51-3.19 (m, 3H), 1.99-1.81 (m, 1H), 1.35-1.27 (m, 1H); 13C NMR (100 MHz,
DMSO-d6): δ 164.70 & 164.39, 163.85 & 161.39, 140.06 & 139.58, 131.84, 130.05, 118.67 & 118.34,
115.68 & 115.47, 71.31 & 70.48, 70.20 & 69.72, 48.33 & 45.79, 42.61 & 38.63, 32.20 & 29.98; LC-MS
(ESI) m/z Calcd. for C14H16FNO3: 265.11, Found: 266.23 [M+H]+.
(E)-1-(trans-3,4-Dihydroxypiperidin-1-yl)-3-(4-(trifluoromethyl) phenyl) prop-2-en-1-one (12b):
1
Yield: 72.0%; Liquid; H NMR (400 MHz, DMSO-d6): δ 7.92 (t, J = 7.2 Hz, 2H), 7.74 (d, J = 8.0 Hz, 2H),
7.50 (dd, J = 15.2, 5.2 Hz, 1H), 7.39 (t, J = 14.4 Hz, 1H), 4.99-4.96 (m, 1H, OH), 4.87-4.83 (m, 1H, OH),
4.12-3.06 (m, 6H), 1.90-1.82 (m, 1H), 1.33-1.29 (m, 1H); 13C NMR (100 MHz, DMSO-d6): δ 164.41 &
164.03, 139.50-139.01 (CF3), 128.57, 128.47, 125.49, 122.76, 121.82, 121.47, 71.19 & 70.44, 70.05 &
69.47, 48.32 & 45.78, 42.66 & 38.64, 32.15 & 29.83; LC-MS (ESI) m/z Calcd. for C15H16F3NO3: 315.11,
Found: 316.14 [M+H]+.
(E)-1-(trans-3,4-Dihydroxypiperidin-1-yl)-3-(4-hydroxyphenyl)prop-2-en-1-one (12c):
1
Yield: 62.0%; H NMR (400 MHz, DMSO-d6): δ 9.79 (s, 1H, OH), 7.51 (d, J = 8.0 Hz, 2H), 7.36 (d, J =
15.6 Hz, 1H), 6.98 (d, J = 15.6 Hz, 1H), 6.77 (d, J = 8.8 Hz, 2H), 4.96 (br s, 1H, OH), 4.82 (br s, 1H, OH),
4.18-3.35 (m, 3H), 3.29-3.13 (m, 3H), 1.82 (br s, 1H), 1.76-1.22 (m, 1H); 13C NMR (100 MHz, DMSO-
d6): δ 164.98 & 164.66, 138.42, 135.47 & 135.06, 127.56 & 127.36, 127.19, 125.97, 118.03 & 117.66,
71.41 & 70.54, 70.33 & 69.91, 48.35 & 45.82, 42.60, 30.09 & 28.96; LC-MS (ESI) m/z Calcd. for
C14H17NO4: 263.12, Found: 262.39[M-H]-.
(E)-1-(trans-3,4-Dihydroxypiperidin-1-yl)-3-(thiophen-3-yl)prop-2-en-1-one (12d):
1
Yield: 72.0%; MR: 125-130 °C; H NMR (400 MHz, DMSO-d6): δ 7.84 (s, 1H), 7.58 (s, 2H), 7.46 (d, J =
14.8 Hz, 1H), 7.06 (dd, J = 14.8, 8.0 Hz, 1H), 5.00 (br s, 1H, OH), 4.87 (br s, 1H, OH), 4.14-3.60 (m, 3H),
3.46-3.39 (m, 1H), 3.29-3.15 (m, 2H), 1.86-1.82 (m, 1H), 1.29-1.24 (m, 1H); 13C NMR (100 MHz,
DMSO-d6): δ 165.12, 158.85, 141.72 & 141.23, 129.65, 126.26, 115.53, 114.85, 70.44, 70.01, 45.86,
42.67, 30.22; LC-MS (ESI) m/z Calcd. for C12H15NO3S: 253.08, Found: 254.16 [M+H]+.
tert-Butyl 4-(3-(trans-3,4-dihydroxypiperidin-1-yl)-3-oxopropyl) phenylcarbamate (12i):
Yield: 78.0%; Liquid 1H NMR (400 MHz, DMSO-d6): δ 9.16 (s, 1H, NH), 7.32 (d, J = 8.0 Hz, 2H), 7.09 (d,
J = 8.40 Hz, 2H), 4.93-4.91 (m, 1H, OH), 4.81-4.77 (m, 1H, OH), 4.06-3.34 (m, 3H), 3.25-3.04 (m, 3H),
2.71 (t, J = 7.2 Hz, 2H), 2.56-2.52 (m, 2H), 1.79-1.72 (m, 1H), 1.46 (9H, s), 1.23-1.21 (m, 1H); 13C NMR
(100 MHz, DMSO-d6): δ 170.03, 152.74, 137.27, 135.00, 128.33, 118.10, 78.72, 71.33 & 70.41, 69.92
& 69.69, 48.20 & 45.20, 42.49 & 37.95, 34.07, 31.83, 30.69 & 29.89, 28.08; LC-MS (ESI) m/z Calcd. for
C19H28N2O5: 364.20, Found: 365.30 [M+H]+.

22
ACCEPTED MANUSCRIPT
(E)-N-(4-(3-(trans-3,4-Dihydroxypiperidin-1-yl)-3-oxopropyl)phenyl)-3-(4-(trifluoromethyl)phenyl)
acrylamide (13a):
1
Yield: 64.0%; MR: 169-176 °C; H NMR (400 MHz, DMSO-d6): δ 10.22 (s, 1H, NH), 7.84-7.79 (m, 4H),
7.66-7.58 (m, 3H), 7.20 (d, J = 8.4 Hz, 2H), 6.95 (d, J = 16.0 Hz, 1H), 4.94 (br s, 1H, OH), 4.82-4.80 (m,
1H, OH), 4.07-3.44 (m, 3H), 3.27-3.01 (m, 3H), 2.77 (t, J = 8.0 Hz, 2H), 2.66-2.55 (m, 2H), 1.81-1.73
(m, 1H), 1.27-1.19 (m, 1H); 13C NMR (100 MHz, DMSO-d6): δ 169.99 & 169.76, 162.77, 138.82,
138.08, 136.90, 136.74 & 136.62, 129.47, 129.16, 128.59, 128.22, 125.82 & 128.78, 125.20, 119.22,
71.32 & 70.41, 69.92 & 69.68, 48.19 & 45.21, 42.49 & 37.97, 33.97 & 33.92, 31.82, 30.20 & 29.88;
LC-MS (ESI) m/z Calcd. for C24H25F3N2O4: 462.18, Found: 463.21 [M+H]+.
(E)-N-(4-(3-(trans-3,4-Dihydroxypiperidin-1-yl)-3-oxopropyl)phenyl)-3-(4-hydroxyphenyl)acryl
amide (13b):
Yield: 58.0%; MR: 230-234 °C; 1H NMR (400 MHz, DMSO-d6): δ 10.0 (s, 1H, NH), 9.87 (s, 1H, OH), 7.57
(d, J = 8.8 Hz, 2H), 7.48-7.43 (m, 3H), 7.17 (d, J = 8.4 Hz, 2H), 6.82 (d, J = 8.4 Hz, 2H), 6.59 (d, J = 15.6
Hz, 1H), 4.94-4.93 (m, 1H, OH), 4.82-4.78 (m, 1H, OH), 4.07-3.36 (m, 3H), 3.10-3.00 (m, 3H), 2.77-
2.73 (m, 2H), 2.62-2.56 (m, 2H), 1.78-1.72 (m, 1H), 1.23-1.19 (m, 1H); 13C NMR (100 MHz, DMSO-d6):
δ 170.01, 163.76, 159.06, 140.02, 137.27, 136.23, 132.15, 129.37, 128.49, 119.06, 118.67, 115.77,
71.33 & 70.41, 69.92 & 69.68, 48.20 & 45.21, 42.49 & 37.97, 34.01, 31.82, 30.20 & 29.89; LC-MS (ESI)
m/z Calcd. for C23H26N2O5: 410.18, Found: 411.08 [M+H]+.
tert-Butyl 4-(3-(4-(3-(trans-3,4-dihydroxypiperidin-1-yl)-3-oxopropyl) phenylamino)-3-oxopropyl)
phenylcarbamate (13e):
Yield: 82.0%; MR: 190-195 °C; 1H NMR (400 MHz, DMSO-d6): δ 9.73 (s, 1H, NH), 9.15 (s, 1H, NH), 7.41
(d, J = 8.4 Hz, 2H), 7.30 (d, J = 8.0 Hz, 2H), 7.08 (t, J = 8.8 Hz, 4H), 4.88 (br s, 1H, OH), 4.76 (d, J = 6.4
Hz, 1H, OH), 4.03-3.39 (m, 3H), 3.26-2.96 (m, 3H), 2.78 (t, J = 8.0 Hz, 2H), 2.69 (t, J = 7.2 Hz, 2H), 2.52-
2.46 (m, 4H), 1.73-1.68 (m, 1H), 1.26-1.15 (m, 1H), 1.42 (s, 9H); 13C NMR (100 MHz, DMSO-d6): δ
170.13, 170.03, 169.80, 152.75, 137.38, 137.04, 136.08, 134.65, 128.38 & 128.27, 119.04, 118.16,
78.77, 71.33 & 70.41, 69.93 & 69.68, 48.20 & 45.21, 42.90 & 38.05, 37.97, 34.03, 31.82, 30.21, 29.89,
28.09; LC-MS (ESI) m/z Calcd. for C28H37N3O6: 511.27, Found: 512.41 [M+H]+.
General procedure for the preparation of compounds 5f-j, 7e-g, 12e-h and 13c-d:
To a solution of α, β-unsaturated amides (1.0 mol) in EtOH (10 v) under the nitrogen atmosphere
was added 10% Pd/C (0.2 mol), the reaction mixture was hydrogenated under 60 psi at RT for 4 h.
After completion of the reaction, the reaction mixture was filtered through celite pad, the filtrate
was evaporated in vacuo to get the crude material. The crude product was purified by column
chromatography to afford 5f-j, 7e-g, 12e-h and 13c-d as solids/liquids in 80-94% yield.

23
ACCEPTED MANUSCRIPT
1-(cis-3,4-Dihydroxypiperidin-1-yl)-3-phenylpropan-1-one (5f):
1
Yield: 94.0%; MR: 103-106 °C; H NMR (400 MHz, DMSO-d6): δ 7.34-7.28 (m, 5H), 3.70-3.58 (m, 2H),
3.54-3.48 (m, 2H), 3.37-3.29 (m, 2H), 2.83-2.78 (m, 2H), 2.64-2.57 (m, 2H), 1.61-1.40 (m, 2H); 13C
NMR (100 MHz, DMSO-d6): δ 170.18 & 169.75, 141.80 & 141.68, 129.53, 129.35, 123.17, 68.20 &
67.86, 67.71 & 67.32, 48.17, 43.31, 33.88 & 33.73, 30.54 & 30.25, 30.19 & 29.11; LC-MS (ESI) m/z
Calcd. for C14H19NO3: 249.14, Found: 250.15 [M+H]+.
1-(cis-3,4-Dihydroxypiperidin-1-yl)-3-(4-fluorophenyl)propan-1-one (5g):
Yield: 84.0%; MR: 123-126 °C; 1H NMR (400 MHz, DMSO-d6): δ 7.25 (t, J = 8.0 Hz, 2H), 7.07 (t, J = 8.80
Hz, 2H), 4.59-4.48 (m, 2H, OH), 3.70-3.62 (m, 2H), 3.52-3.36 (m, 2H), 3.22-3.18 (m, 1H), 3.09-3.05 (m,
1H), 2.79-2.77 (m, 2H), 2.60-2.56 (m, 2H), 1.61-1.42 (m, 2H); 13C NMR (100 MHz, DMSO-d6): δ 170.23
& 169.80, 160.61 (d), 137.67 (d), 130.13, 114.82 (d), 68.14 & 67.79, 67.64 & 67.24, 48.12, 43.19,
34.13 & 34.05, 29.97 &, 29.90, 29.09; LC-MS (ESI) m/z Calcd. for C14H18FNO3: 267.13, Found: 268.09
[M+H]+.
1-(cis-3,4-Dihydroxypiperidin-1-yl)-3-(4-(trifluoromethyl)phenyl) propan-1-one (5h):
Yield: 85.0%; MR: 103.106 °C; 1H NMR (400 MHz, DMSO-d6): δ 7.62 (d, J = 8.0 Hz, 2H), 7.45 (d, J = 7.6
Hz, 2H), 4.83-4.57 (m, 2H, OH), 3.78-3.54 (m, 3H), 3.36-3.04 (m, 3H), 2.89 (br s, 2H), 2.68-2.54 (m,
2H), 1.67-1.38 (m, 2H); 13C NMR (100 MHz, DMSO-d6): δ 170.05 & 169.61, 146.74 & 146.64, 129.30 &
129.23, 126.73 & 125.84, 125.02 & 124.99, 123.14, 68.19 & 67.80, 67.66 & 67.25, 48.15, 43.27, 33.53
& 33.39, 30.55 & 30.46, 29.07;LC-MS (ESI) m/z Calcd. for C15H18F3NO3: 317.12, Found: 318.23 [M+H]+.
1-(cis-3,4-Dihydroxypiperidin-1-yl)-3-(4-hydroxyphenyl)propan-1-one (5i):
Yield: 80.0%; MR: 205-208 °C; 1H NMR (400 MHz, DMSO-d6): δ 7.00-6.93 (t, J = 8.0 Hz, 2H), 6.65 (dd, J
= 8.8, 2.0 Hz, 2H), 3.70-3.43 (m, 3H), 3.30-3.02 (m, 3H), 2.79-2.52 (m, 4H), 1.66-1.41 (m, 2H); LC-MS
(ESI) m/z Calcd. for C14H19NO4: 265.13, Found: 266.08 [M+H]+.
1-(cis-3,4-Dihydroxypiperidin-1-yl)-3-(thiophen-3-yl)propan-1-one (5j):
Yield: 87.0%; Thick liquid; 1H NMR (400 MHz, DMSO-d6): δ 7.41 (dd, J = 4.8, 2.8 Hz, 1H), 7.17 (s, 1H),
7.01 (s, 1H), 4.63-4.49 (m, 2H, OH), 3.76-3.04 (m, 6H), 2.81-2.73 (m, 2H), 2.67-2.53 (m, 2H), 1.67-1.42
(m, 2H); 13C NMR (100 MHz, DMSO-d6): δ 170.29 & 169.89, 141.86, 128.44, 125.53, 120.48 & 120.35,
68.10 & 67.75, 67.58 & 67.24, 48.06, 43.19, 33.20 & 33.05, 30.51, 29.04; LC-MS (ESI) m/z Calcd. for
C12H17NO3S: 255.09, Found: 256.11 [M+H]+.
N-(4-(3-(cis-3,4-Dihydroxypiperidin-1-yl)-3-oxopropyl)phenyl)-3-(4-fluorophenyl)propanamide
(7e):
Yield: 78%; MR: 127-129 °C; 1H NMR (400 MHz, DMSO-d6): δ 9.81 (s, 1H, NH), 7.45 (d, J = 8.4 Hz, 2H),
7.27 (t, J = 8.4 Hz, 2H), 7.14-7.07 (m, 4H), 4.67-4.51 (m, 2H, OH), 3.73-3.62 (m, 2H), 3.52-3.47 (m,
1H), 3.34-3.29 (m, 1H), 3.21-3.16 (m, 1H), 3.09-3.03 (m, 1H), 2.88 (t, J = 8.4 Hz, 2H), 2.72 (t, J = 7.4 Hz,

24
ACCEPTED MANUSCRIPT
2H), 2.60-2.53 (m, 4H), 1.63-1.53 (m, 1H), 1.44-1.42 (m, 1H); 13C NMR (100 MHz, DMSO-d6): δ 170.34
& 170.0, 169.91, 161.87 & 159.47, 137.33 & 137.02, 136.20 & 136.07, 130.05 & 129.96, 128.52 &
128.45, 119.05, 115.05, 114.83, 68.13 & 67.79, 67.63 & 67.23, 48.13, 43.16, 38.16 & 37.94, 34.20 &
34.11, 30.57 & 30.28, 30.21 & 29.96, 29.08; LC-MS (ESI) m/z Calcd. for C23H27FN2O4: 414.45, Found:
415.17 [M+H]+.
N-(4-(3-(cis-3,4-Dihydroxypiperidin-1-yl)-3-oxopropyl)phenyl)-3-(4-(trifluoromethyl)phenyl)
propanamide (7f):
Yield: 71.0%; MR: 94-97 °C; 1H NMR (400 MHz, DMSO-d6): δ 9.82 (s, 1H, NH), 7.64 (d, J = 8.4 Hz, 2H),
7.48-7.43 (m, 4H), 7.13 (d, J = 8.4 Hz, 2H), 4.59-4.47 (m, 2H, OH), 3.70-3.62 (m, 2H), 3.52-3.47 (m,
1H), 3.37-3.36 (m, 1H), 3.21-3.18 (m, 1H), 3.16-3.07 (m, 1H), 2.99 (t, J = 7.6 Hz, 2H), 2.73 (t, J = 7.2 Hz,
2H), 2.59-2.53 (m, 4H), 1.61-1.54 (m, 1H), 1.44-1.40 (m, 1H); 13C NMR (100 MHz, DMSO-d6): δ 170.29,
169.72, 146.20, 136.94, 136.22, 129.05, 128.39, 126.85 & 126.54, 125.71, 125.05, 119.06, 68.08 &
67.74, 67.58 & 67.20, 48.08, 43.14, 37.20, 34.04, 30.47, 30.15, 29.05; LC-MS (ESI) m/z Calcd. for
C24H27F3N2O4: 464.19, Found: 465.09 [M+H]+.
N-(4-(3-(cis-3,4-Dihydroxypiperidin-1-yl)-3-oxopropyl)phenyl)-3-(4-hydroxyphenyl)propanamide
(7g):
Yield: 68.0%; MR: 224-228 °C; 1H NMR (400 MHz, DMSO-d6): δ 9.78 (s, 1H, NH), 9.14 (s, 1H, OH), 7.45
(d, J = 8.4 Hz, 2H), 7.13 (d, J = 8.4 Hz, 2H), 7.01 (d, J = 8.4 Hz, 2H), 6.65 (d, J = 8.4 Hz, 2H), 4.67-4.51
(m, 2H, OH), 3.71-3.62 (m, 2H), 3.52-3.49 (m, 1H), 3.30-3.28 (m, 1H), 3.21-3.18 (m, 1H), 3.08-3.04 (m,
1H), 2.79-2.71 (m, 4H), 2.59-2.49 (m, 4H), 1.60-1.54 (m, 1H), 1.44-1.39 (m, 1H); LC-MS (ESI) m/z
Calcd. for C23H28N2O5: 412.20, Found: 413.09 [M+H]+.
1-(trans-3,4-Dihydroxypiperidin-1-yl)-3-(4-fluorophenyl)propan-1-one (12e):
Yield: 79.0%; Thick gum 1H NMR (400 MHz, DMSO-d6): δ 7.26 (dd, J = 8.4, 5.6 Hz, 2H), 7.08 (t, J = 8.0
Hz, 2H), 4.93 (br s, 1H, OH), 4.81 (br s, 1H, OH), 3.57-3.53 (m, 2H), 3.43-3.41 (m, 1H), 3.14-3.01 (m,
3H), 2.78 (t, J = 7.6 Hz, 2H), 2.66-2.60 (m, 2H), 1.67-1.66 (m, 1H), 1.23-1.22 (m, 1H); 13C NMR (100
MHz, DMSO-d6): δ 169.88 & 169.65, 161.77 & 159.37, 137.59 & 137.51, 130.06 & 129.99, 114.83 &
114.63, 71.30 & 70.40, 69.88 & 69.64, 48.14 & 45.20, 42.45 & 37.95, 33.92 & 33.85, 31.79, 29.86; LC-
MS (ESI) m/z Calcd. for C14H18FNO3: 267.13, Found: 268.09 [M+H]+.
1-(trans-3,4-Dihydroxypiperidin-1-yl)-3-(4-(trifluoromethyl)phenyl) propan-1-one (12f):
1
Yield: 81.0%; MR: 89-92 °C; H NMR (400 MHz, DMSO-d6): δ 7.62 (d, J = 7.6 Hz, 2H), 7.47 (d, J = 7.6
Hz, 2H), 4.97 (br s, 1H, OH), 4.85 (dd, J = 11.2, 3.2 Hz, 1H, OH), 4.06-3.44 (m, 2H), 4.06-3.44 (m, 1H),
3.32-3.04 (m, 3H), 2.89 (t, J = 7.6 Hz, 2H), 2.87-2.63 (m, 2H), 1.78-1.74 (m, 1H), 1.25-1.21 (m, 1H); 13
NMR (100 MHz, DMSO-d6): δ 169.73 & 169.49, 146.69 & 146.58, 129.25 & 129.21, 126.75-125.81,
C

25
ACCEPTED MANUSCRIPT
124.99 & 124.95, 123.11, 71.29 & 70.42, 69.83 & 69.55, 40.08 & 45.27, 42.23 & 37.99, 33.34, 31.81,
30.43 & 29.83; LC-MS (ESI) m/z Calcd. for C15H18F3NO3: 317.12, Found: 318.19 [M+H]+.
1-(trans-3,4-Dihydroxypiperidin-1-yl)-3-(4-hydroxyphenyl)propan-1-one (12g):
1
Yield: 72.0%; Thick gum; H NMR (400 MHz, DMSO-d6): δ 9.05 (s, 1H, OH), 6.95 (d, J = 8.4, 2.0 Hz,
2H), 6.60 (d, J = 8.0 Hz, 2H), 4.89-4.86 (m, 1H, OH), 4.78-4.74 (m, 1H, OH), 4.01-3.30 (m, 3H), 3.20-
2.93 (m, 3H), 2.62 (d, J = 8.0 Hz, 2H), 2.58-2.49 (m, 2H), 1.73-1.66 (m, 1H), 1.28-1.25 (m, 1H); 13C
NMR (100 MHz, DMSO-d6): δ 170.64 & 170.42, 155.85, 131.96 & 131.84, 129.56, 115.42, 71.87 &
70.93, 70.47 & 70.25, 48.73 & 45.68, 42.09 & 38.46, 34.91, 32.33, 30.45; LC-MS (ESI) m/z Calcd. for
C14H19NO4: 265.13, Found: 266.43 [M+H]+.
1-(trans-3,4-Dihydroxypiperidin-1-yl)-3-(thiophen-3-yl)propan-1-one (12h):
Yield: 80.0%; MR: 82-86 °C; 1H NMR (400 MHz, DMSO-d6): δ 7.41 (t, J = 4.0 Hz, 1H), 7.17 (s, 1H), 7.01
(d, J = 4.4 Hz, 1H), 4.94-4.91 (m, 1H, OH), 4.82-4.78 (m, 1H, OH), 4.06-3.56 (m, 2H), 3.44-3.41 (m, 1H),
3.28-3.01 (m, 3H), 2.79 (t, J = 7.2 Hz, 2H), 2.69-2.62 (m, 2H), 1.81-1.72 (m, 1H), 1.25-1.19 (m, 1H); 13
C
NMR (100 MHz, DMSO-d6): δ 169.99 & 169.77, 141.82 & 141.71, 128.45, 125.53, 120.47 & 120.38,
71.31 & 70.40, 69.89 & 69.66, 48.12 & 45.21, 42.43 & 37.97, 33.01, 31.80, 29.86; LC-MS (ESI) m/z
Calcd. for C12H17NO3S: 255.09, Found: 256.18 [M+H]+.
N-(4-(3-(trans-3,4-Dihydroxypiperidin-1-yl)-3-oxopropyl)phenyl)-3-(4-(trifluoromethyl)phenyl)
propanamide (13c):
1
Yield: 84.0%; MR: 169-174 °C; H NMR (400 MHz, DMSO-d6): δ 9.81 (s, 1H, NH), 7.64 (d, J = 8.0 Hz,
2H), 7.48-7.43 (m, 4H), 7.13 (d, J = 8.4 Hz, 2H), 4.93-4.92 (m, 1H, OH), 4.81-4.78 (m, 1H, OH), 4.06-
3.42 (m, 3H), 3.25-3.04 (m, 3H), 2.99 (t, J = 7.6 Hz, 2H), 2.73 (t, J = 8.0 Hz, 2H), 2.66 (t, J = 8.0 Hz, 2H),
2.7-2.54 (m, 2H), 1.78-1.74 (m, 1H), 1.24-1.21 (m, 1H); LC-MS (ESI) m/z Calcd. for C24H27F3N2O4:
464.19, Found: 465.30 [M+H]+.
N-(4-(3-(trans-3,4-Dihydroxypiperidin-1-yl)-3-oxopropyl)phenyl)-3-(4-hydroxyphenyl)propanamide
(13d):
Yield: 76.0%; MR: 174-178 °C; 1H NMR (400 MHz, DMSO-d6): δ 9.75 (s, 1H, NH), 9.11 (s, 1H, OH), 7.45
(d, J = 8.4 Hz, 2H), 7.13 (d, J = 8.4 Hz, 2H), 7.01 (d, J = 8.4 Hz, 2H), 6.65 (d, J = 8.4 Hz, 2H), 4.93-4.91
(m, 1H, OH), 4.82-4.77 (m, 1H, OH), 4.06-3.37 (m, 3H), 3.25-3.00 (m, 3H), 2.78-2.71 (m, 4H), 2.58-
2.51 (m, 4H), 1.79-1.72 (m, 1H), 1.24-1.18 (m, 1H); 13C NMR (100 MHz, DMSO-d6): δ 170.25, 170.18 &
169.79, 155.40, 137.07, 136.06 & 135.93, 131.18, 129.00, 128.39, 119.03, 115.01, 71.33 & 70.41,
69.92 & 69.68, 48.19 & 45.22, 42.49 & 38.36, 37.96, 34.03, 31.82, 30.15, 30.07 & 29.90; LC-MS (ESI)
m/z Calcd. for C23H28N2O5: 412.20, Found: 413.33 [M+H]+.

26
ACCEPTED MANUSCRIPT
General procedure for the preparation of compounds 6a-c and 8a-c:
To a stirred solution of amine (1.0 mol) in THF (10 v) was added pyridine (5 mol), after 5 min,
sulfonyl chloride derivative (1.1 mol) was added at RT under the nitrogen atmosphere stirred for 16
h. After completion of the reaction, the reaction mixture was diluted with water (50 v), extracted
with EtOAc (50 v X 2), solvent evaporated under reduced pressure. The crude product was purified
by column chromatography to afford 6a-c and 8a-c as solids/liquids in 55-72% yield.
cis-1-(4-Fluorophenylsulfonyl)piperidine-3,4-diol (6a):
Yield: 68.0%; Thick liquid; 1H NMR (400 MHz, DMSO-d6): δ 7.83-7.79 (m, 2H), 7.48 (t, J = 6.8 Hz, 2H),
3.63-3.53 (m, 2H), 3.10-3.04 (m, 2H), 2.70-2.59 (m, 2H), 1.78-1.52 (m, 2H); 13C NMR (100 MHz,
DMSO-d6): δ 164.48 (d), 132.09, 130.36 (d), 116.48 (d), 67.33, 65.77, 47.01, 41.01, 29.64; LC-MS (ESI)
m/z Calcd. for C11H14FNO4S: 275.06, Found: 276.04 [M+H]+.
cis-1-(4-(Trifluoromethyl)phenylsulfonyl)piperidine-3,4-diol (6b):
Yield: 65.0%; Thick liquid; 1H NMR (400 MHz, DMSO-d6): δ 8.04 (d, J = 8.4 Hz, 2H), 7.97 (d, J = 8.0 Hz,
2H), 3.63-3.54 (m, 2H), 3.11 (t, J = 12.0 Hz, 2H), 2.75 (t, J = 9.6 Hz, 2H), 2.67 (t, J = 10.4 Hz, 2H), 1.72-
1.68 (m, 1H), 1.63-1.60 (m, 1H); 13C NMR (100 MHz, DMSO-d6): δ 139.68, 133.15-132.19 (m), 128.39,
126.60 (d), 124.87 (d), 67.31, 65.83, 47.15, 41.21, 29.45; LC-MS (ESI) m/z Calcd. for C12H14F3NO4S:
325.06, Found: 323.95 [M-H]-.
cis-1-(4-(Trifluoromethoxy)phenylsulfonyl)piperidine-3,4-diol (6c):
Yield: 72.0%; Thick liquid; 1H NMR (400 MHz, DMSO-d6): δ 7.86 (d, J = 8.8 Hz, 2H), 7.63 (d, J = 8.0 Hz,
2H), 4.83 (d, J = 5.6 Hz, 1H, OH), 4.51 (d, J = 4.0 Hz, 1H, OH), 3.63-3.54 (m, 2H), 3.17-3.06 (m, 2H),
2.75-2.66 (m, 2H), 1.72-1.59 (m, 2H); LC-MS (ESI) m/z Calcd. for C12H14F3NO5S: 341.05, Found: 342.21
[M+H]+.
N-(4-(3-(cis-3,4-Dihydroxypiperidin-1-yl)-3-oxopropyl)phenyl)-4-fluorobenzenesulfonamide (8a):
1
Yield: 64.0%; MR: 221-224 °C; H NMR (400 MHz, DMSO-d6): δ 10.13 (s, 1H, NH), 7.80-7.77 (m, 2H),
7.38 (d, J = 8.8 Hz, 2H), 7.09 (d, J = 8.4 Hz, 2H), 6.96 (d, J = 8.0 Hz, 2H), 4.70-4.52 (m, 2H, OH), 3.67-
3.02 (m, 6H), 2.70-2.42 (m, 4H), 1.56-1.41 (m, 2H); LC-MS (ESI) m/z Calcd. for C20H23FN2O5S: 422.13,
Found: 423.29 [M+H]+.
N-(4-(3-(cis-3,4-Dihydroxypiperidin-1-yl)-3-oxopropyl)phenyl)-4-(trifluoromethyl)benzene
sulfonamide (8b):
1
Yield: 62.0%; MR: 194-197; H NMR (400 MHz, DMSO-d6): δ 10.39 (m, 1H, NH), 7.94 (t, J = 9.6 Hz,
4H), 7.10 (d, J = 8.4 Hz, 2H), 6.98 (d, J = 8.0 Hz, 2H), 4.65-4.50 (m, 2H, OH), 3.71-3.59 (m, 2H), 3.49-
3.44 (m, 1H), 3.28-3.26 (m, 1H), 3.19-3.16 (m, 1H), 3.06-3.02 (m, 1H), 2.69-2.67 (m, 2H), 2.55-2.53
(m, 2H), 1.57-1.52 (m, 1H), 1.45-1.36 (m, 1H); LC-MS (ESI) m/z Calcd. for C21H23F3N2O5S: 472.13,
Found: 473.14 [M+H]+.

27
ACCEPTED MANUSCRIPT
N-(4-(3-(cis-3,4-Dihydroxypiperidin-1-yl)-3-oxopropyl)phenyl)-4-(trifluoromethyl)-N-(4-(trifluoro
methyl)phenylsulfonyl)benzene sulfonamide (8c):
Yield: 55.0%; MR: 215-219 °C; 1H NMR (400 MHz, DMSO-d6): δ 8.13-8.08 (m, 8H), 7.36 (d, J = 8.0 Hz,
2H), 7.03 (d, J = 8.0 Hz, 2H), 4.69-4.54 (m, 2H, OH), 3.75-3.50 (m, 3H), 3.38-3.05 (m, 3H), 2.88-2.85
(m, 2H), 2.72-2.64 (m, 2H), 1.65-1.40 (m, 2H); 13C NMR (100 MHz, DMSO-d6): δ 170.08 & 169.66,
144.98, 142.12, 134.23 & 133.90, 130.97, 130.57, 129.89 & 129.81, 129.13, 126.97, 124.56, 68.11 &
67.79, 67.64 & 67.19, 48.12, 43.22, 33.27, 30.57 & 30.34, 29.08; LC-MS (ESI) m/z Calcd. for
C23H28N2O5: 412.20, Found: 413.33 [M+H]+; LC-MS (ESI) m/z Calcd. for C28H26F6N2O7S2: 680.11, Found:
681.18 [M+H]+.
4.2.Biology (α-glucosidase enzyme inhibition assay)
4.2.1. Test concentration
The stock solutions (10mM) of standards and each test substances were prepared in 100%
Dimethyl Sulfoxide (DMSO, Sigma Chemical Co., St. Louis, MO) and further diluted with PBS to obtain
an experimental concentration of 1-0.25 mM (also 0.125 and 0.062 for potent compounds).
4.2.2. Protocol for α-glucosidase enzyme assay
The inhibitory activity assay procedure was performed by optimizing the previously reported
method [41-44]. α-Glucosidase enzyme (0.1U/ml) was dissolved in 1mM concentration of phosphate
buffer (pH 6.9) and was prepared fresh every time. The initial step was performed by mixing 10 µL of
the test sample with 40 µL of prepared enzyme solution and incubated for 15-20 min at 37 °C. Then
40 µL of p-nitrophenyl-α-D-glycopyranoside (PNPG) substrate (0.1mM) was added and incubated for
45-60 min. The release of p-nitrophenol by quenching effect was determined with the addition of
100 µL of 0.1 M Na2CO3. Further, the enzymatic activity was quantified in proportion to the level of p-
nitrophenol spectrophotometrically with absorbance reading at 415nm. Blank reading was taken
without the test compound and with enzyme and substrate. Acarbose, Voglibose and Miglitol were
used as positive controls.
4.2.3. Data interpretation
The readings taken at 415nm were further evaluated for their percentage inhibition of test
compounds (Table 3). The equation used was:
((Ablank – Asample) / Ablank ) *100
The IC50 values were calculated plotting graphs with percentage inhibition on the y-axis and log
concentrations on x-axis using graph pad prism v 6.0. The IC50 values are reported as best fit value
after normalization of data (n=3)

28
ACCEPTED MANUSCRIPT
Acknowledgements
Authors wish to sincerely thank GVK Biosciences Pvt. Ltd., for the Higher Education Program,
financial support and encouragement. Help from the analytical department for all spectral analysis is
highly appreciated. We are thankful to Dr. Sudhir Kumar Singh for his immense support and
motivation. We are also thankful to JNTUH, Hyderabad BITS-Pilani and NIPER Hyderabad.
References and notes
[1]
N.J. Morrish, S.L. Wang, L.K. Stevens, J.H. Fuller, H. Keen, WHO Multinational Study Group.
Diabetologia 44 (2001) S14-S21.
[2]
[3]
S.P. Marso, W.R. Hiatt, J. Am. Coll. Cardiol. 47 (2006) 921-929.
A. Norhammar, K. Malmberg, E. Diderholm, B. Lagerqvist, B. Lindahl, L. Rydén, L. Wallentin, J.
Am. Coll. Cardiol. 43 (2004) 585-591.
[4]
J.J. Duby, R.K. Campbell, S.M. Setter, K.A. Rasmussen, Am. J. Health-Syst. Ph. 61 (2004) 160-
173.
[5]
[6]
[7]
M. Davies, S. Brophy, R. Williams, A. Taylor, Diabetes care 29 (2006) 1518-1522.
T. Behl, I. Kaur, A. Kotwani, Survey of ophthalmology 61 (2016) 187-196.
R. Pop-Busui, A.j. Boulton, E.L. Feldman, V. Bril, R. Freeman, R.A. Malik, J.M. Sosenko, D.
Ziegler, Diabetes Care 40 (2017) 136-154.
[8]
[9]
A.I. Adler, E.J. Boyko, J.H. Ahroni, D.G. Smith, Diabetes care 22 (1999) 1029-1035.
J. Apelqvist, G. Ragnarson-Tennvall, J. Larsson, U. Persson, J. Intern. Med. 235 (1994) 463-
471.
[10] M. Edmonds, Drugs 66 (2006) 913-929.
[11] W.J. Jeffcoate, K.G. Harding, Lancet 361 (2003) 1545-1551.
[12] H. Jayasekara, R.J. MacInnis, R. Room, D.R. English, Alcohol and alcoholism 51 (2015) 315-
330.
[13] L.H. Kushi, C. Doyle, M. McCullough, C.L. Rock, W. Demark-Wahnefried, E.V. Bandera, S.
Gapstur, A.V. Patel, K. Andrews, T. Gansler, CA Cancer. J. Clin. 62 (2012) 30-67.
[14] D.M. Parkin, L. Boyd, L.C. Walker, Brit. J. Cancer. 105 (2011) S77-S81.
[15] E. Ritz, I. Rychlík, F. Locatelli, S. Halimi, Am. J. Kidney. Dis. 34 (1999) 795-808.
[16] R.C. Atkins, E.M. Briganti, J.B. Lewis, L.G. Hunsicker, G. Braden, P.J.C. de Crespigny, G.
DeFerrari, P. Drury, F. Locatelli, T.B. Wiegmann, E.J. Lewis, Am. J. Kidney. Dis. 45 (2005) 281-
287.
[17] D.S. Fong, L. Aiello, T.W. Gardner, G.L. King, G. Blankenship, J.D. Cavallerano, F.L. Ferris, R.
Klein, Diabetes care 27 (2004) s84-s87.

29
ACCEPTED MANUSCRIPT
[18] J.M. Tarr, K. Kaul, K. Wolanska, E.M. Kohner, R. Chibber, Diabetes (2013) 88-106.
[19] I. Aboderin, A. Kalache, Y. Ben-Shlomo, J.W. Lynch, C.S. Yajnik, D. Kuh, D. Yach, Life Course
Perspectives on Coronary Heart Disease, Stroke and Diabetes: Key Issues and Implications
for Policy and Research. Geneva, World Health Organization, 2001.
[20] H.E. Lebovitz, Diabetes Rev. 7 (1999) 139-153.
[21] U. Quast, D. Stephan, S. Bieger, U. Russ, Diabetes 53 (2004) S156-S164.
[22] R.A. Easom, M. Landt, J.R. Colca, J.H. Hughes, J. Turk, M. McDaniel, J. Biol. Chem. 265 (1990)
14938-46.
[23] J.M. Olefsky, A.R. Saltiel, Diabetes 45 (1996) 1661-1669.
[24] B. Hulin, P.A. McCarthy, E.M. Gibbs, Curr. Pharm. Design. 2 (1996) 85-102.
[25] T.M. Willson, P.J. Brown, D.D. Sternbach, B.R. Henke, J. Med. Chem. 43 (2000) 527-550.
[26] S. Mudaliar, R.R. Henry, Ann. Rev. Med. 52 (2001) 239-257.
[27] V. Bhatia, P. Viswanathan, Curr. Opin. Invest. Dr. 7 (2006) 891-897.
[28] C.J. Bailey, Gen. Pharmacol. 24 (1993) 1299-1309.
[29] C.J. Dunn, D.H. Peters, Drugs 49 (1995) 721-749.
[30] S. Obici, B.B. Zhang, G. Karkanias, L. Rossetti, Nat. Med. 8 (2002) 1376-1382.
[31] D.S. Edgerton, K.M. Johnson, A.D. Cherrington, Front. Biosci.-Landmrk. 14 (2009) 1169.
[32] P.D. Home, E.M. Home, Diabetic. Med. 22 (2005) 1460-1460.
[33] F.A. Van De Laar, P.L. Lucassen, Diabetes care 28 (2005) 1841-1841.
[34] R. Tundis, M.R. Loizzo, F. Menichini, Mini-rev. Med. Chem. 10 (2010) 315-331.
[35] A.J. Scheen, Drugs 63 (2003) 933-951.
[36] G. Derosa, P. Maffioli, Arch. Med. Sci. 8 (2012) 899-906.
[37] S. Kasturi, S. Surarapu, C.C. Bathoju, S. Uppalanchi, S. Dwivedi, Y. Perumal, D.K. Sigalapalli,
B.N. Babu, K.S. Ethiraj, J.S. Anireddy, Med. Chem. Comm. 8 (2017) 1618-1630.
[38] S. Kasturi, S. Surarapu, S. Uppalanchi, J.S. Anireddy, S. Dwivedi, H.S. Anantaraju, Y. Perumal,
D.K. Sigalapalli, B.N. Babu, K.S. Ethiraj, Bioorg. Med. Chem. Lett. 27 (2017) 2818-2823.
[39] A. Mochizuki, Y. Nakamoto, H. Naito, K. Uoto, T. Ohta, Bioorg. Med. Chem. Lett. 18 (2008)
782-787.
[40] A. Boto, R. Hernandez, Y. de Leon, J.R. Murguıa, A. Rodrıguez-Afonso, Tetrahedron Lett. 45
(2004) 6841-6845.
[41] T. Damsud, S. Adisakwattana, P. Phuwapraisirisan, Phytochem. Lett. 6 (2013) 350-354.
[42] N. K. N. A. Zawawi, M. Taha, N. Ahmat, N. H. Ismail, A. Wadood, F. Rahim, Bioorg. Chem., 70
(2017) 184-191.