Synthesis and α-amylase inhibitory activity of glucose- deoxynojirimycin conjugates

Article abstract of DOI:10.1016/j.tet.2011.08.012

Inhibitors of α-amylase have attracted attention for their putative effects against diabetes mellitus. Although numerous studies have explored natural small molecule inhibitors, acarbose is currently the only compound with sufficient inhibitory potency and drug-like characteristics to be considered as a potential therapeutic agent. We have synthesized conjugates of the potent glucosidase inhibitor, 1-deoxynojirimycin, and glucose, with the aim of enhancing inhibitory activity against α-amylase. This synthetic conjugate showed increased inhibition of α-amylase compared to 1-deoxynojirimycin alone, suggesting that similar modifications of existing glucosidase inhibitors may yield more potent α-amylase inhibitors.

Full text of DOI:10.1016/j.tet.2011.08.012

Tetrahedron 67 (2011) 7692e7702
Contents lists available at ScienceDirect
Tetrahedron
journal homepage: www.elsevier.com/locate/tet
Synthesis and
conjugates
a
-amylase inhibitory activity of glucoseedeoxynojirimycin
*
Eisuke Kato, Naoya Iwano, Akihiko Yamada, Jun Kawabata
Laboratory of Food Biochemistry, Division of Applied Bioscience, Graduate School of Agriculture, Hokkaido University, Kita-ku, Sapporo, Hokkaido 060-8589, Japan
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 1 June 2011
Received in revised form 4 August 2011
Accepted 4 August 2011
Available online 10 August 2011
Inhibitors of a-amylase have attracted attention for their putative effects against diabetes mellitus. Al-
though numerous studies have explored natural small molecule inhibitors, acarbose is currently the only
compound with sufficient inhibitory potency and drug-like characteristics to be considered as a potential
therapeutic agent. We have synthesized conjugates of the potent glucosidase inhibitor, 1-
deoxynojirimycin, and glucose, with the aim of enhancing inhibitory activity against
a-amylase. This
synthetic conjugate showed increased inhibition of -amylase compared to 1-deoxynojirimycin alone,
suggesting that similar modifications of existing glucosidase inhibitors may yield more potent a-amylase
inhibitors.
a
Keywords:
a
-Amylase inhibitor
Glucosidase inhibitor
1-Deoxynojirimycin
Amylase
Ó 2011 Elsevier Ltd. All rights reserved.
Diabetes mellitus
1. Introduction
utilized small molecule inhibitor.6 Several peptide inhibitors have
been identified,7 but instability in the harsh gastric environment
prohibits their use as medicines against T2DM. Development of
Glucosidases play roles in a variety of crucial processes in the
human body, one of which is the digestion of energy-containing
polysaccharides. Several different glucosidases participate in this
a small molecule
a-amylase inhibitor will increase clinicians’ op-
tions for the treatment of T2DM. We here show our approach to-
process, including salivary/pancreatic
a
-amylase and intestinal
a
-
ward the design and synthesis of a small molecule
inhibitor.
a-amylase
glucosidases (e.g., maltaseeglucoamylase complex and sucrasee
isomaltase complex). These enzymes hydrolyze polysaccharides to
monosaccharides, which are then absorbed from the intestine into
the blood stream. In type 2 diabetes mellitus (T2DM), failure to
remove monosaccharides from the blood into the tissues leads to
hyperglycemia in patients, which raises the risk of cardiovascular
disease, renal failure, blindness and neurological disorders.1 In-
hibition of polysaccharide digestion prevents rapid glucose uptake
from the intestine and alleviates the hyperglycemic threat caused
by food intake. Accordingly, much effort has been put into the de-
velopment of glycosidase inhibitors for the treatment of T2DM.
a
-Amylase is an enzyme that hydrolyzes polysaccharides, such
as starch. Although a member of the glucosidase family, their
substrate recognition is more specific toward polysaccharides. Its
binding site consists of several partitions called ‘sub-sites’, which
individually recognize a sugar unit.8,9 Each sub-site has relatively
low affinity toward the sugar unit, but by recognizing multiple
sugar units with multiple sub-sites, a-amylase increases its affinity
toward a polysaccharide, enabling specific binding and hydrolysis.9
This multiple sub-site system precludes a low molecular weight
compound from being an efficient inhibitor. Most glucosidase in-
hibitors work as an active site inhibitor by mimicking glucose or its
For intestinal
a-glucosidases, several potent inhibitors are
known including deoxynojirimycin (DNJ),2 salacinol,3 miglitol, and
voglibose.4 The last two compounds are currently used therapeu-
tically for T2DM. Moreover, many natural compounds are reported
activated state.10
a
-Amylase possesses a similar active site to other
glucosidases,9 but small molecule inhibitors like DNJ mimics only
a single glucose unit and thus can have only low affinity toward
amylase. The small molecule -amylase inhibitor, acarbose, inhibits
the active site of -amylase by its core structure, acarviosine, but
has increased affinity toward -amylase due to additional sugar
a
-
to have
a
-glucosidase inhibitory activity.5 However, few small
a
molecule inhibitors have been reported for
a compound used for the treatment of T2DM, is the only widely
a
-amylase. Acarbose,
a
a
units within its molecular structure. We believe that the addition of
a sugar unit to an active site inhibitor could be the key to de-
veloping small molecule
have designed and synthesized a series of glucoseeDNJ conjugates
a-amylase inhibitors. Accordingly, we
* Corresponding author. Tel./fax: þ81 11 706 2496; e-mail address: junk@
chem.agr.hokudai.ac.jp (J. Kawabata).
0040-4020/$ e see front matter Ó 2011 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tet.2011.08.012

E. Kato et al. / Tetrahedron 67 (2011) 7692e7702
7693
that have DNJ as an active site inhibitor connected through an alkyl
linker to an additional glucose. These conjugates were tested for
inhibitory activity against -amylase.
a
2. Results and discussion
2.1. Synthesis of glucoseeDNJ conjugates
We chose two types of glucoseeDNJ conjugates (8aec, 13aef) to
develop and test for
a-amylase inhibitory activity. Compounds
8aec have a glucose attached through the nitrogen atom of DNJ,
while in Compounds 13aef it is attached through the DNJ 4-OH
group to place the glucose at an alternative sub-site. The length
of the alkyl linker was varied to optimize its flexibility and to place
the glucose accurately at a sub-site.
For the synthesis of 8aec, benzyl protected DNJ (6) was pre-
pared and coupled with the glucose-linker conjugate (5).11 1,2,3,6-
Tetra-O-benzyl-a-D-glucopyranose (2) was reacted with alkyl bro-
mide (1) to give 4-O-bromoalkylated glucose (3). After removal of
the THP group, the resulting alcohol (4) was oxidized by
DesseMartin periodinane to an aldehyde (5). Aldehyde (5) and 6
were then coupled by a reductive amination method, and removal
of benzyl groups from the resulting conjugate (7) gave the products
(8aec), in which the DNJ and glucose are connected by alkyl linkers
of 6, 9, and 12 atom lengths, respectively (Scheme 1).
Scheme 2. Reagents and conditions: (a) CBr4, PPh3, CH2Cl2 then TMU, TEAB, bro-
moalkyl alcohol; (b) 11, NaH, DMF; (c) Pd(OH)2, H2, 1 M HCl aq, THF, EtOH.
elimination of a bromide. It is reported that bromobutyl glycosides
can be utilized as a glycosyl donor by assisting the formation of an
intramolecular furan ring, which is considered as an activated
state.13 As a pyrane ring can also be formed stably, bromopentyl
Scheme 1. Reagents and conditions: (a) NaH, DMF; (b) PPTS, EtOH, 55 ꢀC; (c) DesseMartin periodinane, CH2Cl2; (d) 6, NaBH3CN, AcOH, MeOH, CH2Cl2; (e) Pd/C, H2, 1 M HCl aq,
EtOH.
Conjugates 13aec were prepared in the following order. 2,3,4,6-
glycoside may act in the same manner. Thus, attributing this
intramolecular ring formation as the reason for bromide elimina-
tion, we chose to connect an alkyl linker with DNJ (11) before
attaching glucose. Alkyl iodide (17) was first reacted with 11, and
subsequent removal of the PMB group gave 19. This was then used
Tetra-O-benzyl- -glucopyranose (9) was subjected to a-selective
D
glycosylation with bromoalkyl alcohol to afford 10.12 This was then
coupled with DNJ (11) under basic conditions using NaH (with DMF
as a solvent), which gave 12 at a low yield. Removal of the pro-
tective groups from 12 afforded 13aec (Scheme 2).
as a glycosyl acceptor in the
give 20 as the product. Deprotection of 20 gave 13e,f (Scheme 4).
Also, to ensure the effect of glucose in -amylase inhibition, com-
a-selective glycosylation reaction to
Synthesis of 13d required modification of a reaction condition,
as the procedure using
u
-bromopentadecyl glucoside and 11 with
a
NaH as a base gave no product. To increase the reactivity, the
leaving group was replaced from a bromide to an iodide, and as the
solubility of 15 in DMF was relatively low compared to 10aec, THF
was used as a solvent. Using this fixed substrate and solvent, re-
action of 15 and 11 was facilitated and gave 16 as a product, which
was then applied to a hydrogenation step to remove the protective
groups to give 13d (Scheme 3).
pounds 23aef were synthesized either by deprotection of the in-
termediate product or by coupling alkyl halide with 11 (Scheme 5).
2.2.
a-Amylase inhibitory activity of glucoseeDNJ conjugates
Initially, 8aec and 13aec were tested for their
hibitory activity to assess the effects of linking DNJ and glucose
through different linker groups. Commercial porcine pancreatic a-
a-amylase in-
Synthesis of 13e and 13f also required modification of a reaction,
as the reaction of 2,3,4,6-tetra-O-benzyl-1-O-(4-bromobutyl)-
glucopyranose and 2,3,4,6-tetra-O-benzyl-1-O-(5-bromopentyl)-
a
-
a
D
-
amylase was used as an enzyme source and 2,4-dinitrophenyl
maltotriose was used as a model substrate.14 Fig. 1 shows the in-
hibitory activity of tested compounds at 3 mM. It can be seen that
-
D-glucopyranose, under basic conditions, resulted only in the

7694
E. Kato et al. / Tetrahedron 67 (2011) 7692e7702
Fig. 1.
a-Amylase inhibitory activity of 8aec and 13aec tested at 3 mM. Acarbose
Scheme 3. Reagents and conditions: (a) CBr4, PPh3, CH2Cl2 then TMU, TEAB, 15-
hydroxypentadecanol; (b) NIS, PPh3, imidazole, CH2Cl2; (c) 11, NaH, THF; (d)
Pd(OH)2, H2, 1 M HCl aq, THF, EtOH.
(20 M) was used as a positive control.
m
Scheme 4. Reagents and conditions: (a) 11, NaH, DMF; (b) TFA, CH2Cl2; (c) 2,3,4,6-tetra-O-benzyl-D-glycosyl bromide, TMU, TEAB, CH2Cl2; (d) Pd(OH)2, H2, 1 M HCl aq, THF, EtOH.
glucose moiety in conjugates 13aec seems to increase effectively
the inhibitory activity of DNJ depending on the length of the alkyl
linker, with the greatest activity being in Compound 13c that has
a 12-carbon linker.
The nitrogen atom of DNJ plays a key role in the inhibition of
glucosidase by giving a positive charge at the position resembling
the activated state of -glucoside hydrolysis by -glucosidase. The
a-
a
a
weak inhibitory activity of 8aec may be due to modification of this
nitrogen atom by an interfering alkyl chain. However, as a similar
nitrogen-modified compound, miglitol, retains
hibitory activity,4a this is unlikely to account for its comparatively
low inhibitory activity relative to 13aec. From the study of -am-
a-glucosidase in-
a
ylase, the sub-site of the enzyme located at the non-reducing end
contributes more than that at the reducing end in the recognition of
substrate.15 The results shown in Fig. 1 appear to confirm this and
indicate the benefits of attaching an additional moiety through the
4-OH group of DNJ.
To investigate the effect of linker length on a-amylase inhibition,
Scheme 5. Reagents and conditions: (a) 11, NaH, THF/DMF, TBAI (for synthesis of
22aec); (b) PPTS, MeOH then 1 M HCl aq, Pd(OH)2, H2; (c) Pd(OH)2, H2, 1 M HCl aq,
MeOH.
and also to optimize the efficacy of the glucose moiety, we tested
and compared 13aef together with 23aef. The results are sum-
marized in Table 1. Compounds 13a,e,f and 23a,e,f had relatively
low inhibitory activity and we were unable to define IC50 values for
these compounds. Therefore, these compounds were compared at
5 mM. For Compounds 13b,c,d and 23b,c, IC50 values were calcu-
lated, but 23d had low solubility under assay conditions and could
DNJ has negligible inhibitory activity toward
a-amylase, as do
Compounds 8a and 8b, with only a minor increase in inhibitory
activity in Compound 8c, suggesting that the glucose moiety in
these compounds has little effect on DNJ activity. In contrast, the

E. Kato et al. / Tetrahedron 67 (2011) 7692e7702
7695
measured using a SynergyÔ MX (Bio-tech Instruments Inc.,)
microplate reader.
Table 1
-Amylase inhibitory activity of synthetic glucoseeDNJ conjugates
a
Linker length
Inhibition at 5 mM (%)
IC50 (mM)
(number of atoms)
4.2. Synthesis of glucoseeDNJ conjugate
13
23
13
23
e
f
a
b
c
d
DNJ
4
5
6
22
23
32
70
97
d
7
12
19
25
64
d
d
>5.00
>5.00
>5.00
2.29
0.77
1.12
>5.00
>5.00
>5.00
3.15
1.20
d
4.2.1. General procedure for the synthesis of 3. 1,2,3,6-Tetra-O-ben-
zyl-a-D-glucopyranose (2, 1 equiv) was dissolved in DMF and 60%
NaH (2 equiv) in oil was added at 0 ꢀC. After stirring the mixture for
30 min at room temperature (rt), 1 (1.2 equiv) dissolved in DMF was
added and stirred for 24 h. The reaction was quenched by adding
MeOH and water was added to the resulting solution. The solution
was extracted by EtOAc, dried over sodium sulfate, and evaporated
to dryness. The residue was purified by silica-gel column chroma-
tography to give 3.
9
12
15
0
>5.00
d: Unable to define inhibition due to low solubility.
not be tested. From our results, the length of the linker has a pri-
mary effect on -amylase inhibition, and the inhibition gradually
a
increased by adding length to the linker. The most potent was 13c,
and shorter or longer linkers negatively affected the inhibitory ac-
tivity, although reduced solubility of 13d (15 carbon linker) might
be masking a further increase in activity in this compound. The
effect of the glucose moiety can be seen from the inhibitory activity
of 13 and 23. Regardless of the linker length, addition of a glucose
moiety increases the inhibitory activity. However, the increase in-
duced by addition of the glucose moiety was smaller than expected,
and the enhancement of inhibitory activity appears to depend
4.2.1.1. 1,2,3,6-Tetra-O-benzyl-4-O-[6-(tetrahydropyranyloxy)
hexyl]-a-D
-glucopyranose (3a). Oil, yield 69%; 1H NMR (500 MHz,
CDCl3): 7.23e7.39 (20H, m), 4.93 (1H, d, J¼10.8 Hz), 4.80 (1H, d,
J¼3.5 Hz), 4.76 (1H, d, J¼10.8 Hz), 4.59e4.69 (3H, m), 4.46e4.54
(4H, m), 3.90 (1H, dd, J¼9.3, 9.3 Hz), 3.84 (1H, m), 3.63e3.76 (4H,
m), 3.56 (1H, dd, J¼1.9, 10.6 Hz), 3.45e3.49 (2H, m), 3.36e3.41 (2H,
m), 3.32 (1H, dt, J¼6.7, 9.6 Hz), 1.17e1.83 (14H, m) ppm; 13C NMR
(67.5 MHz, CDCl3): 138.8, 138.1, 137.8, 137.1, 128.3, 128.2, 127.74,
127.72, 127.68, 127.64, 127.53, 127.46, 127.3, 98.7, 95.4, 81.9, 79.6,
77.7, 75.5, 73.3, 73.0, 72.8, 70.4, 68.9, 68.3, 67.4, 62.1, 30.6, 30.2, 29.5,
heavily on the length of the alkyl linker. From the structure of a-
amylase, the substrate-binding site of the enzyme is surrounded by
a hydrophobic surface.16 The effect of the alkyl linker is presumably
a result of binding to this surface. Furthermore, although the glu-
cose moiety is generally hydrophilic, the top and bottom of the
pyranose ring are hydrophobic, and may thus contribute somewhat
to its affinity. The fact that addition of an extra moiety to the small
molecule glucosidase inhibitor, DNJ, increased its inhibition against
26.0, 25.9, 25.3, 19.5 ppm; ½a D25
þ52.0 (c 1.00, CHCl3); HR-ESI-MS
ꢁ
(positive) [MþNa]þ found m/z 747.3854, C45H56O8Naþ requires
m/z 747.3867.
4.2.1.2. 1,2,3,6-Tetra-O-benzyl-4-O-[9-(tetrahydropyranyloxy)
nonyl]-a-D
-glucopyranose (3b). Oil, yield 89%; 1H NMR (500 MHz,
CDCl3): 7.23e7.39 (20H, m), 4.93 (1H, d, J¼10.8 Hz), 4.80 (1H, d,
J¼3.6 Hz), 4.77 (1H, d, J¼10.8 Hz), 4.47e4.69 (7H, m), 3.91 (1H, dd,
J¼9.3, 9.3 Hz), 3.86 (1H, m), 3.69e3.77 (3H, m), 3.65 (1H, dd, J¼3.7,
10.6 Hz), 3.56 (1H, dd, J¼1.9, 10.6 Hz), 3.46e3.50 (2H, m), 3.34e3.42
(3H, m), 1.14e1.85 (20H, m) ppm; 13C NMR (67.5 MHz, CDCl3):
138.8, 138.1, 137.8, 137.1, 128.2, 128.1, 127.72, 127.70, 127.63, 127.49,
127.42, 127.31, 98.6, 95.4, 81.9, 79.6, 77.7, 75.4, 73.3, 73.0, 72.8, 70.4,
68.8, 68.3, 67.5, 62.1, 30.6, 30.2, 29.6, 29.4, 29.31, 29.26, 26.1, 26.0,
a
-amylase is an important breakthrough in the development of
small molecule glucosidase inhibitors against a-amylase using ra-
tionally designed modification.
3. Conclusion
In conclusion, we have synthesized glucoseeDNJ conjugates
connected by alkyl linkers of various lengths. Addition of glucose
25.3, 19.5 ppm; ½a D25
þ50.4 (c 1.00, CHCl3); HR-ESI-MS (positive)
ꢁ
through the nitrogen atom of DNJ had a negligible effect on
amylase inhibition but addition through the 4-OH group dramati-
cally increased -amylase inhibitory activity. Among the synthe-
sized compounds, the most effective was 13c, which has dodecyl
linker between the DNJ and glucose moieties. Our results show the
importance of hydrophobic interactions in
We aim to utilize this hydrophobic interaction to develop more
potent DNJ-based -amylase inhibitors.
a-
[MþNa]þ found m/z 789.4326, C48H62O8Naþ requires m/z 789.4337.
a
4.2.1.3. 1,2,3,6-Tetra-O-benzyl-4-O-[12-(tetrahydropyranyloxy)
dodecyl]-a-D
-glucopyranose (3c). Oil, yield 80%; 1H NMR (500 MHz,
CDCl3): 7.23e7.39 (20H, m), 4.93 (1H, d, J¼10.8 Hz), 4.80 (1H, d,
J¼3.6 Hz), 4.77 (1H, d, J¼10.8 Hz), 4.47e4.69 (7H, m), 3.91 (1H, dd,
J¼9.3, 9.3 Hz), 3.85 (1H, m), 3.69e3.77 (3H, m), 3.65 (1H, dd, J¼3.7,
10.6 Hz), 3.56 (1H, dd, J¼1.9, 10.6 Hz), 3.46e3.50 (2H, m), 3.34e3.42
(3H, m), 1.20e1.84 (26H, m) ppm; 13C NMR (67.5 MHz, CDCl3):
138.8, 138.1, 137.9, 137.1, 128.3, 128.2, 128.1, 127.74, 127.66, 127.53,
127.45, 127.33, 127.31, 98.6, 95.4, 81.9, 79.6, 77.7, 75.4, 73.3, 73.0,
72.8, 70.4, 68.8, 68.3, 67.5, 62.1, 30.6, 30.3, 29.6, 29.44, 29.40, 29.3,
a-amylase inhibition.
a
4. Experimental section
4.1. General methods
26.1, 26.0, 25.4, 19.5 ppm; ½a D25
þ48.2 (c 1.00, CHCl3); HR-ESI-MS
ꢁ
Porcine pancreatic amylase was purchased from SigmaeAldrich
(positive) [MþNa]þ found m/z 831.4790, C51H68O8Naþ requires
m/z 831.4806.
Co. and 2,4-dinitrophenyl a-maltotriose was synthesized according
to the literature.14 All other commercially available chemicals were
purchased from Wako Pure Chem. Ind. Ltd. and used without fur-
ther purification. Structures of synthetic compounds were de-
termined by NMR and mass spectrometry. Bruker AMX500 or Jeol
JNM-EX 270 was used to obtain NMR spectra and either tetrame-
thylsilane (TMS), tert-butanol or residual solvent peaks were used
as an internal standard (1H NMR: TMS 0.00 ppm (CDCl3), CD3OD
3.30 ppm, tert-butanol 1.24 ppm (D2O); 13C NMR: CDCl3 77.0 ppm,
CD3OD 49.0 ppm, tert-butanol 30.3 ppm (D2O)). Jeol JMS SX-102A
FAB-MS or Jeol JMS-T100GCV (FD-MS) or Thermo Scientific Exac-
tive (ESI-MS) was used to obtain mass spectra. Absorbance was
4.2.2. General procedure for the synthesis of 4. Compound
3
(1 equiv) was dissolved in EtOH and PPTS (10 mol %) was added. The
solution was stirred for 6 h at 50 ꢀC, poured in satd NaHCO3 aq and
extracted by EtOAc. Organic layer was dried over sodium sulfate,
evaporated, and purified by silica-gel column chromatography to
give 4.
4.2.2.1. 1,2,3,6-Tetra-O-benzyl-4-O-(6-hydroxyhexyl)-a-D-gluco-
pyranose (4a). Oil, yield 97%; 1H NMR (500 MHz, CDCl3): 7.23e7.39
(20H, m), 4.94 (1H, d, J¼10.9 Hz), 4.80 (1H, d, J¼3.6 Hz), 4.76 (1H, d,

7696
E. Kato et al. / Tetrahedron 67 (2011) 7692e7702
J¼10.9 Hz), 4.46e4.69 (6H, m), 3.91 (1H, dd, J¼9.5 Hz), 3.70e3.76
(2H, m), 3.64 (1H, dd, J¼3.6, 10.5 Hz), 3.56 (1H, m), 3.48 (1H, dd,
J¼3.6, 9.5 Hz), 3.38e3.42 (2H, m), 1.22e1.54 (8H, m) ppm; 13C NMR
(67.5 MHz, CDCl3): 138.8, 138.0, 137.8, 137.0, 128.3, 128.2, 127.74,
127.66, 127.54, 127.45, 127.32, 95.4, 81.8, 79.5, 77.6, 75.4, 73.2, 72.9,
95.4, 81.9, 79.5, 77.6, 75.4, 73.2, 73.0, 72.8, 70.3, 68.8, 68.3, 43.6, 30.1,
29.09, 29.07, 28.9, 25.9, 21.8 ppm; ½a D25
þ56.2 (c 1.00, CHCl3); HR-
ꢁ
ESI-MS (positive) [MþNa]þ found m/z 703.3621, C43H55O7Naþ re-
quires m/z 703.3605.
72.8, 70.3, 68.8, 68.3, 62.5, 32.4, 30.1, 25.8, 25.5 ppm; ½a D26
ꢁ
þ67.1 (c
4.2.3.3. 1,2,3,6-Tetra-O-benzyl-4-O-(12-oxododecyl)-a-D-gluco-
1.00, CHCl3); HR-ESI-MS (positive) [MþNa]þ found m/z 663.3292,
C40H48O7Naþ requires m/z 663.3292.
pyranose(5c). Oil, yield 97%; 1H NMR (500 MHz, CDCl3): 9.74 (1H, t,
J¼1.8 Hz), 7.24e7.40 (20H, m), 4.93 (1H, d, J¼10.9 Hz), 4.81 (1H, d,
J¼3.7 Hz), 4.76 (1H, d, J¼10.9 Hz), 4.47e4.70 (6H, m), 3.91 (1H, dd,
J¼9.3 Hz), 3.73 (2H, m), 3.65 (1H, dd, J¼3.6, 10.6 Hz), 3.57 (1H, dd,
J¼2.0, 10.6 Hz), 3.48 (1H, dd, J¼3.7, 9.6 Hz), 3.40 (2H, m), 2.38 (2H,
dt, J¼1.8, 7.4 Hz), 1.20e1.64 (18H, m) ppm; 13C NMR (67.5 MHz,
CDCl3): 202.9, 138.9, 138.1, 137.9, 137.1, 128.36, 128.25, 128.23,
128.21, 127.84, 127.74, 127.72, 127.62, 127.53, 127.42, 95.5, 82.0, 79.6,
77.7, 75.6, 73.4, 73.2, 72.9, 70.4, 68.9, 68.4, 43.8, 30.3, 29.5, 29.4,
4.2.2.2. 1,2,3,6-Tetra-O-benzyl-4-O-(9-hydroxynonyl)-a-D-gluco-
pyranose (4b). Oil, yield quant.; 1H NMR (500 MHz, CDCl3):
7.23e7.39 (20H, m), 4.93 (1H, d, J¼10.8 Hz), 4.80 (1H, d, J¼3.6 Hz),
4.77 (1H, d, J¼10.8 Hz), 4.47e4.69 (6H, m), 3.91 (1H, dd, J¼9.2,
9.3 Hz), 3.70e3.76 (2H, m), 3.64 (1H, dd, J¼3.8, 10.6 Hz), 3.61 (1H,
m), 3.56 (1H, dd, J¼2.0, 10.6 Hz), 3.48 (1H, dd, J¼3.6, 9.6 Hz),
3.37e3.42 (2H, m), 1.17e1.56(14H, m) ppm; 13C NMR (67.5 MHz,
CDCl3): 138.7, 138.0, 137.8, 137.0, 128.2, 128.1, 127.69, 127.68, 127.60,
127.49, 127.40, 127.29, 95.3, 81.8, 79.5, 77.6, 75.4, 73.2, 73.0, 72.8,
70.3, 68.8, 68.3, 62.5, 32.5, 30.2, 29.32, 29.24, 29.17, 25.9, 25.5 ppm;
29.32, 29.26, 29.1, 26.1, 22.0 ppm; ½a D25
þ56.9 (c 1.00, CHCl3); HR-
ꢁ
ESI-MS (positive) [MþNa]þ found m/z 745.4096, C46H58O7Naþ re-
quires m/z 745.4075.
½
a 2D6
ꢁ
þ62.8 (c 1.00, CHCl3); HR-ESI-MS (positive) [MþNa]þ found
4.2.4. General procedure for the synthesis of 7. Compound 5
m/z 705.3760, C43H54O7Naþ requires m/z 705.3762.
(1 equiv) and 6 (1.2 equiv) were immersed in MeOH/AcOH (200/1)
and CH2Cl2 was added until all the components dissolves. The so-
lution was cooled to 0 ꢀC, 90% NaBH3CN (2 equiv) was added and
stirred for 12 h at rt. The reaction mixture was concentrated and
purified by preparative TLC (PTLC) to give 7.
4.2.2.3. 1,2,3,6-Tetra-O-benzyl-4-O-(12-hydroxydodecyl)-a-D-glu-
copyranose (4c). Oil, yield 91%; 1H NMR (500 MHz, CDCl3):
7.23e7.39 (20H, m), 4.93 (1H, d, J¼10.8 Hz), 4.80 (1H, d, J¼3.6 Hz),
4.77 (1H, d, J¼10.8 Hz), 4.47e4.69 (6H, m), 3.91 (1H, dd, J¼9.3,
9.3 Hz), 3.70e3.77 (2H, m), 3.60e3.66 (3H, m), 3.56 (1H, dd, J¼2.0,
10.6 Hz), 3.48 (1H, dd, J¼3.6, 9.6 Hz), 3.37e3.42 (2H, m), 1.20e1.57
(20H, m) ppm; 13C NMR (67.5 MHz, CDCl3): 138.8, 138.1, 137.9, 137.1,
128.3, 128.23, 128.19, 127.8, 127.7, 127.6, 127.5, 127.4, 95.5, 82.0, 79.6,
77.7, 75.5, 73.3, 73.2, 72.9, 70.4, 68.9, 68.4, 62.8, 32.7, 30.3, 29.5,
4.2.4.1. 1,2,3,6-Tetra-O-benzyl-4-O-[6-[(2R,3R,4R,5S)-3,4,5-
tribenzyloxy-2-benzyloxymethylpiperidino]hexyl]-a-D-glucopyranose
(7a). Oil, yield 95%; 1H NMR (500 MHz, CDCl3): 7.15e7.44 (40H, m),
4.99 (2H, dd, J¼4.0, 10.9 Hz), 4.81e4.91 (5H, m), 4.65e4.74 (5H, m),
4.43e4.59 (6H, m), 3.97 (1H, dd, J¼9.2, 9.3 Hz), 3.77e3.82 (2H, m),
3.60e3.71 (5H, m), 3.41e3.55 (5H, m), 3.10 (1H, dd, J¼4.8, 11.3 Hz),
2.54e2.69 (2H, m), 2.32 (1H, br d, J¼9.4 Hz), 2.25 (1H, dd, J¼10.7,
10.8 Hz), 1.09e1.48 (8H, m) ppm; 13C NMR (67.5 MHz, CDCl3):
138.93, 138.87, 138.48, 138.46, 138.1, 137.9, 137.7, 137.1, 128.3, 128.26,
128.22, 127.82, 127.76, 127.72, 127.62, 127.53, 127.44, 127.42, 127.33,
95.5, 87.3, 82.0, 79.7, 78.48, 78.44, 77.7, 75.5, 75.2, 75.1, 73.4, 73.3,
73.0, 72.9, 72.6, 70.4, 69.0, 68.4, 65.2, 63.5, 54.4, 52.3, 30.4, 27.4,
29.3, 26.1, 25.7 ppm; ½a D26
þ58.2 (c 1.00, CHCl3); HR-ESI-MS (posi-
ꢁ
tive) [MþNa]þ found m/z 747.4236, C46H60O7Naþ requires m/z
747.4231.
4.2.3. General procedure for the synthesis of 5. Compound
4
(1 equiv) was dissolved in CH2Cl2 and DesseMartin Periodinane
(1.2 equiv) was added at 0 ꢀC. After stirring for 90 min at rt, MeOH
was added to quench the reaction. To this solution, Et2O was added
and the precipitate was filtered off by passing through the Celite
pad. Filtrate was evaporated and the residue was purified by silica-
gel column chromatography to give 5.
26.1, 23.4 ppm; ½a D24
þ37.5 (c 0.85, CHCl3); HR-ESI-MS (positive)
ꢁ
[MþH]þ found m/z 1146.6078, C74H84O10Nþ requires m/z
1146.6090.
4.2.4.2. 1,2,3,6-Tetra-O-benzyl-4-O-[9-[(2R,3R,4R,5S)-3,4,5-
4.2.3.1. 1,2,3,6-Tetra-O-benzyl-4-O-(6-oxohexyl)-
a
-
D
-glucopyr-
tribenzyloxy-2-benzyloxymethylpiperidino]nonyl]-a-D-glucopyranose
anose (5a). Oil, yield 82%; 1H NMR (500 MHz, CDCl3): 9.68 (1H, t,
J¼1.8 Hz), 7.23e7.40 (20H, m), 4.95 (1H, d, J¼11.0 Hz), 4.81 (1H, d,
J¼3.6 Hz), 4.74 (1H, d, J¼11.0 Hz), 4.46e4.70 (6H, m), 3.90 (1H, dd,
J¼9.3, 9.3 Hz), 3.72 (2H, m), 3.64 (1H, dd, J¼3.7, 10.5 Hz), 3.55 (1H,
dd, J¼2.0, 10.5 Hz), 3.48 (1H, dd, J¼3.6, 9.6 Hz), 3.35e3.41 (2H, m),
2.31 (2H, dt, J¼1.8, 7.4 Hz), 1.52 (2H, m), 1.41 (2H, m), 1.14e1.28 (2H,
m) ppm; 13C NMR (67.5 MHz, CDCl3): 202.4, 138.8, 138.0, 137.9,
137.1, 128.3, 128.22, 128.19, 127.80, 127.74, 127.70, 127.64, 127.59,
127.52, 127.37, 95.4, 81.9, 79.6, 77.7, 75.4, 73.3, 72.8, 72.6, 70.3, 68.9,
(7b). Oil, yield 88%; 1H NMR (500 MHz, CDCl3): 7.12e7.41 (40H, m),
4.95 (2H, d, J¼10.9 Hz), 4.77e4.88 (5H, m), 4.61e4.70 (5H, m),
4.40e4.56 (6H, m), 3.93 (1H, dd, J¼9.3, 9.3 Hz), 3.72e3.79 (2H, m),
3.57e3.68 (5H, m), 3.53 (1H, dd, J¼2.2, 10.4 Hz), 3.50 (1H, dd, J¼3.6,
9.6 Hz), 3.45 (1H, dd, J¼9.0, 9.0 Hz), 3.39e3.44 (2H, m), 3.08 (1H, dd,
J¼4.8, 11.3 Hz), 2.52e2.68 (2H, m), 2.29 (1H, dd, J¼2.2, 9.5 Hz), 2.22
(1H, dd, J¼10.7, 10.8 Hz), 1.08e1.46 (14H, m) ppm; 13C NMR
(67.5 MHz, CDCl3): 138.92, 138.85, 138.47, 138.45, 138.1, 137.9, 137.7,
137.1, 128.3, 128.22, 128.18, 127.78, 127.72, 127.69, 127.58, 127.49,
127.38, 127.29, 95.5, 87.3, 82.0, 79.6, 78.48, 78.42, 77.7, 75.5, 75.2,
75.0, 73.3, 73.1, 73.0, 72.9, 72.6, 70.4, 68.9, 68.4, 65.2, 63.6, 54.4,
68.3, 43.6, 30.0, 25.6, 21.8 ppm; ½a D24
þ58.1 (c 1.00, CHCl3); HR-ESI-
ꢁ
MS (positive) [MþNa]þ found m/z 661.3148, C40H46O7Naþ requires
m/z 661.3136.
52.3, 30.3, 29.5, 29.4, 27.4, 26.1, 23.4 ppm; ½a D24
þ32.1 (c 1.00,
ꢁ
CHCl3); HR-ESI-MS (positive) [MþH]þ found m/z 1188.6549,
C77H90O10Nþ requires m/z 1188.6559.
4.2.3.2. 1,2,3,6-Tetra-O-benzyl-4-O-(9-oxononyl)-a-D-glucopyr-
anose (5b). Oil, yield 88%; 1H NMR (500 MHz, CDCl3): 9.73 (1H, t,
J¼1.8 Hz), 7.23e7.39 (20H, m), 4.93 (1H, d, J¼10.9 Hz), 4.81 (1H, d,
J¼3.7 Hz), 4.76 (1H, d, J¼10.9 Hz), 4.47e4.69 (6H, m), 3.91 (1H, dd,
J¼9.3 Hz), 3.73 (2H, m), 3.64 (1H, dd, J¼3.6, 10.6 Hz), 3.56 (1H, dd,
J¼2.0, 10.6 Hz), 3.48 (1H, dd, J¼3.7, 9.6 Hz), 3.40 (2H, m), 2.38 (2H,
dt, J¼1.8, 7.3 Hz), 1.54e1.61 (2H, m), 1.42 (2H, m), 1.16e1.27 (8H, m)
ppm; 13C NMR (67.5 MHz, CDCl3): 202.5, 138.8, 138.0, 137.8, 137.0,
128.2, 128.14, 128.11, 127.71, 127.64, 127.60, 127.49, 127.41, 127.29,
4.2.4.3. 1,2,3,6-Tetra-O-benzyl-4-O-[12-[(2R,3R,4R,5S)-3,4,5-
tribenzyloxy-2-benzyloxymethylpiperidino]dodecyl]-a-D-glucopyr-
anose (7c). Oil, yield 61%; 1H NMR (500 MHz, CDCl3): 7.15e7.43
(40H, m), 4.97 (2H, d, J¼10.9 Hz), 4.80e4.91 (5H, m), 4.63e4.73 (5H,
m), 4.43e4.58 (6H, m), 3.96 (1H, dd, J¼9.3, 9.3 Hz), 3.75e3.82 (2H,
m), 3.59e3.70 (5H, m), 3.56 (1H, dd, J¼1.9, 10.4 Hz), 3.52 (1H, dd,
J¼3.6, 9.6 Hz), 3.42e3.50 (3H, m), 3.12 (1H, dd, J¼4.8, 11.3 Hz),

E. Kato et al. / Tetrahedron 67 (2011) 7692e7702
7697
2.56e2.72 (2H, m), 2.32 (1H, dd, J¼2.2, 9.5 Hz), 2.25 (1H, dd, J¼10.8,
10.8 Hz), 1.11e1.49 (20H, m) ppm; 13C NMR (67.5 MHz, CDCl3):
138.98, 138.91, 138.53, 138.51, 138.2, 138.0, 137.7, 137.2, 128.36,
128.27, 128.24, 128.23, 127.85, 127.78, 127.75, 127.62, 127.54, 127.44,
127.34, 95.5, 87.3, 82.0, 79.7, 78.54, 78.49, 77.8, 75.6, 75.2, 75.1, 73.4,
73.2, 73.0, 72.7, 70.5, 69.0, 68.5, 65.2, 63.6, 54.4, 52.4, 30.4, 29.61,
4.75 (1H, d, J¼3.6 Hz), 4.64 (1H, d, J¼12.1 Hz), 4.59 (1H, d,
J¼12.1 Hz), 4.470 (1H, d, J¼10.6 Hz), 4.468 (1H, d, J¼12.1 Hz), 3.98
(1H, dd, J¼9.0, 9.6 Hz), 3.77 (1H, ddd, J¼1.9, 3.6, 10.0 Hz), 3.71 (1H,
dd, J¼3.6, 10.6 Hz), 3.65e3.60 (3H, m), 3.56 (1H, dd, J¼3.6, 9.6 Hz),
3.41 (1H, dt, J¼9.5, 6.5 Hz), 3.36 (2H, t, J¼6.9 Hz), 1.83 (2H, tt, J¼6.9,
7.3 Hz), 1.68e1.58 (2H, m), 1.44 (2H, tt, J¼7.3, 7.3 Hz), 1.38 (2H, tt,
J¼7.2, 7.3 Hz) ppm; 13C NMR (125 MHz, CDCl3, rt): 138.9, 138.3,
138.2, 137.9, 128.33, 128.29 (3C), 127.9, 127.86, 127.82, 127.80, 127.74,
127.60, 127.59, 127.45, 96.9, 82.0, 80.1, 77.7, 75.6, 75.0, 73.4, 73.1,
29.56, 27.5, 26.1, 23.5 ppm; ½a D24
þ33.4 (c 1.00, CHCl3); HR-ESI-MS
ꢁ
(positive) [MþH]þ found m/z 1230.7013, C80H96O10Nþ requires m/
z 1230.7029.
70.1, 68.5, 67.9, 33.7, 32.6, 29.1, 27.9, 25.3 ppm; ½a D27
þ39.0 (c 1.00,
ꢁ
4.2.5. General procedure for the synthesis of 8. Compound 7 was
dissolved in EtOH and acidified by 1 M HCl aq to pH 2. To this so-
lution, 10% Pd on carbon was added and stirred 24 h under hy-
drogen atmosphere. The reaction mixture was passed through
Celite pad, dried under vacuo and purified by LiChrolutÒ RP-18
(Merck Co.) to afford 8 as a mixture of anomers.
CHCl3); HR-FD-MS (positive): fragment ion [MꢂH]þ found m/z
701.2499, C40H46BrOþ6 requires m/z 701.2478.
4.2.6.2. 2,3,4,6-Tetra-O-benzyl-1-O-(9-bromononyl)-a-D-gluco-
pyranose (10b). Oil, yield quant.; 1H NMR (500 MHz, CDCl3, rt):
7.36e7.24 (18H, m), 7.14e7.12 (2H, m), 4.99 (1H, d, J¼10.8 Hz), 4.83
(1H, d, J¼10.6 Hz), 4.81 (1H, d, J¼10.8 Hz), 4.77 (1H, d, J¼12.2 Hz),
4.76 (1H, d, J¼3.6 Hz), 4.64 (1H, d, J¼12.2 Hz), 4.60 (1H, d,
J¼12.3 Hz), 4.470 (1H, d, J¼10.6 Hz), 4.469 (1H, d, J¼12.3 Hz), 3.99
(1H, dd, J¼9.3, 9.5 Hz), 3.78 (1H, ddd, J¼1.9, 3.7, 10.0 Hz), 3.72 (1H,
dd, J¼3.7, 10.5 Hz), 3.65e3.60 (3H, m), 3.56 (1H, dd, J¼3.6, 9.5 Hz),
3.41 (1H, dt, J¼9.8, 6.6 Hz), 3.37 (2H, t, J¼6.9 Hz), 1.83 (2H, tt, J¼6.9,
7.4 Hz), 1.65e1.59 (2H, m), 1.43e1.27 (10H, m) ppm; 13C NMR
(125 MHz, CDCl3, rt): 138.9, 138.3, 138.2, 137.9, 128.32, 128.29 (2C),
128.27, 127.92, 127.87, 127.83, 127.80, 127.72, 127.60, 127.58, 127.45,
96.8, 82.1, 80.1, 77.7, 75.6, 75.0, 73.4, 73.0, 70.1, 68.5, 68.1, 33.9, 32.7,
4. 2. 5.1. 4-O-[6-[(2R, 3R, 4R, 5S)-3, 4, 5-Trihydroxy-2-
hydroxymethylpiperidino]hexyl]-
D
-glucopyranose (8a). Crystal, yield
54%;
b
anomer (major), 1H NMR (500 MHz, D2O): 4.48 (1H, d,
J¼8.0 Hz), 3.58e3.79 (5H, m), 3.54 (1H, m), 3.38e3.44 (2H, m), 3.32
(1H, ddd, J¼1.9, 5.2, 9.8 Hz), 3.25 (1H, dd, J¼9.5, 9.5 Hz), 3.09e3.17
(3H, m), 2.89 (1H, dd, J¼4.9, 11.3 Hz), 2.46e2.64 (2H, m), 2.17 (1H,
dd, J¼11.3, 11.3 Hz), 2.12 (1H, br d, J¼9.1 Hz), 1.17e1.47 (8H, m),
ppm; 13C NMR (125 MHz, D2O): 98.7, 81.2, 80.7, 78.4, 77.9, 77.0, 76.0,
72.9, 71.7, 67.8, 63.3, 60.4, 58.0, 54.8, 31.9, 29.3, 27.9, 25.5 ppm; ½a D27
ꢁ
þ26.7 (c 1.00, MeOH); HR-FAB-MS (positive): [MþH]þ found m/z
426.2343, C18H36NOþ10 requires m/z 426.2339.
29.32, 29.26, 29.23, 28.6, 28.1, 26.1 ppm; ½a D27
þ36.1 (c 1.00, CHCl3);
ꢁ
HR-FD-MS (positive): fragment ion [MꢂH]þ found m/z 743.2980,
C43H52BrOþ6 requires m/z 743.2947.
4. 2. 5. 2. 4-O-[9-[(2R, 3R, 4R, 5S)-3, 4, 5-Trihydroxy-2-
hydroxymethylpiperidino]nonyl]-
D
-glucopyranose
(8b). Crystal,
4.2.6.3. 2,3,4,6-Tetra-O-benzyl-1-O-(12-bromododecyl)-a-D-glu-
yield 37%;
b
anomer (major), 1H NMR (500 MHz, D2O): 4.51 (1H, d,
copyranose (10c). Oil, yield 94%; 1H NMR (500 MHz, CDCl3, rt):
7.36e7.23 (18H, m), 7.17e7.12 (2H, m), 4.99 (1H, d, J¼10.6 Hz), 4.83
(1H, d, J¼10.7 Hz), 4.81 (1H, d, J¼10.6 Hz), 4.77 (1H, d, J¼12.0 Hz),
4.76 (1H, d, J¼3.6 Hz), 4.64 (1H, d, J¼12.0 Hz), 4.60 (1H, d,
J¼12.2 Hz), 4.47 (1H, d, J¼10.7 Hz), 4.46 (1H, d, J¼12.2 Hz), 3.99 (1H,
dd, J¼9.3, 9.6 Hz), 3.78 (1H, ddd, J¼2.1, 3.6, 10.0 Hz), 3.72 (1H, dd,
J¼3.6, 10.6 Hz), 3.65e3.60 (3H, m), 3.56 (1H, dd, J¼3.6, 9.6 Hz), 3.42
(1H, dt, J¼9.7, 6.6 Hz), 3.37 (2H, t, J¼6.9 Hz), 1.82 (2H, tt, J¼6.9,
7.2 Hz), 1.65e1.59 (2H, m), 1.43e1.24 (16H, m) ppm; 13C NMR
(125 MHz, CDCl3, rt): 138.9, 138.3, 138.2, 137.9, 128.28, 128.25 (2C),
128.24, 127.9, 127.81 (2C), 127.77, 127.68, 127.56, 127.54, 127.41, 96.8,
82.0, 80.1, 77.7, 75.6, 75.0, 73.4, 73.0, 70.0, 68.5, 68.1, 33.9, 32.7, 29.5,
J¼7.9 Hz), 3.61e3.82 (5H, m), 3.55 (1H, m), 3.41e3.46 (2H, m), 3.34
(1H, ddd, J¼2.1, 5.4, 9.8 Hz), 3.27 (1H, dd, J¼9.5, 9.5 Hz), 3.11e3.20
(3H, m), 2.92 (1H, dd, J¼4.9, 11.4 Hz), 2.48e2.66 (2H, m), 2.20 (1H,
dd, J¼11.0, 11.2 Hz), 2.15 (1H, dd, J¼2.3, 9.7 Hz), 1.16e1.48 (14H, m)
ppm; 13C NMR (125 MHz, D2O): 98.7, 81.2, 80.7, 78.4, 77.9, 77.0, 76.1,
73.0, 71.7, 67.8, 63.3, 60.5, 58.1, 54.9, 32.0, 31.3, 31.3, 31.2, 29.5, 27.9,
25.5 ppm; ½a 2D7
þ27.0 (c 2.00, MeOH); HR-FAB-MS (positive):
ꢁ
[MþH]þ found m/z 468.2818, C21H42NO1þ0 requires m/z 468.2809.
4.2.5.3. 4-O-[12-[(2R,3R,4R,5S)-3,4,5-Trihydroxy-2-
hydroxymethylpiperidino]dodecyl]-
D-glucopyranose
(8c). Crystal,
yield 50%;
b
anomer (major), 1H NMR (500 MHz, D2O): 4.51 (1H, d,
29.44, 29.43, 29.33, 29.32 (2C), 28.7, 28.1, 26.1 ppm; ½a D27
þ28.1 (c
ꢁ
J¼7.9 Hz), 3.49e3.79 (6H, m), 3.41e3.48 (2H, m), 3.34 (1H, m), 3.31
(1H, dd, J¼9.4, 9.4 Hz), 3.12e3.16 (3H, m), 2.90 (1H, dd, J¼4.3,
11.0 Hz), 2.52e2.67 (2H, m), 2.19 (1H, dd, J¼11.0, 11.0 Hz), 2.11 (1H,
br d, J¼2.3, 9.8 Hz), 1.15e1.50 (20H, m) ppm; 13C NMR (125 MHz,
D2O): 98.7, 81.3, 80.8, 78.7, 78.1, 77.2, 76.1, 72.8, 71.7, 67.9, 63.5, 60.3,
58.6, 55.1, 32.6, 32.3, 32.2, 32.2, 32.2, 32.1, 32.0, 29.5, 28.5,
1.00, CHCl3); HR-FD-MS (positive): fragment ion [MꢂH]þ found m/z
785.3448, C46H58BrOþ6 requires m/z 785.3417.
4.2.7. General procedure for the synthesis of 12. Compounds 10
(1.2 equiv) and 11 (1 equiv) were dissolved in dry DMF. The solution
was cooled to 0 ꢀC and NaH (1.5 equiv) was added and stirred under
nitrogen atmosphere. After 15 h, water was added and the solution
was extracted by EtOAc. Organic layer was washed with brine, dried
over sodium sulfate, and evaporated. The residue was purified by
PTLC to give 12.
25.8 ppm; ½a 2D7
þ24.6 (c 1.00, MeOH); HR-FAB-MS (positive):
ꢁ
[MþH]þ found m/z 510.3271, C24H48NO1þ0 requires m/z 510.3278.
4.2.6. General procedure for the synthesis of 10. Compound 9
(1 equiv) was dissolved in CH2Cl2 and Ph3P (4.5 equiv), CBr4
(4.5 equiv) was added. After stirring for 4 h, TMU (6.8 equiv), bro-
moalkyl alcohol (3 equiv) and TEAB (1.2 equiv) was added and
further stirred for 12 h. The reaction mixture was diluted with
CHCl3, washed with satd NaHCO3 aq and brine. The organic layer
was dried over sodium sulfate, evaporated, and purified by silica-
gel column chromatography to give 10.
4.2.7.1. (2R,3R,4R,5S)-4,5-Dibenzyloxy-1-benzyloxycarbonyl-2-
benzyloxymethyl-3-[6-(2,3,4,6-tetra-O-benzyl-a-D-glucopyr-
anosyloxy)hexyloxy] piperidine (12a). Oil, yield 61%; 1H NMR
(500 MHz, CDCl3, rt): 7.35e7.23 (38H, m), 7.14e7.12 (2H, m), 5.12
(1H, d, J¼12.4 Hz), 5.09 (1H, d, J¼12.4 Hz), 4.98 (1H, d, J¼10.9 Hz),
4.83 (1H, d, J¼10.4 Hz), 4.81 (1H, d, J¼10.9 Hz), 4.76 (1H, d,
J¼12.3 Hz), 4.75 (1H, d, J¼3.7 Hz), 4.67 (1H, d, J¼11.5 Hz), 4.65 (1H,
d, J¼11.9 Hz), 4.64 (1H, d, J¼12.3 Hz), 4.63 (1H, d, J¼11.5 Hz), 4.59
(1H, d, J¼12.2 Hz), 4.51 (1H, d, J¼11.9 Hz), 4.47 (1H, d, J¼10.8 Hz),
4.45 (1H, d, J¼12.2 Hz), 4.44 (1H, d, J¼11.9 Hz), 4.42 (1H, d,
J¼11.9 Hz), 4.10e4.05 (2H, m), 3.98 (1H, dd, J¼9.0, 9.6 Hz),
4.2.6.1. 2,3,4,6-Tetra-O-benzyl-1-O-(6-bromohexyl)-a-D-gluco-
pyranose (10a). Oil, yield quant.; 1H NMR (500 MHz, CDCl3, rt):
7.36e7.24 (18H, m), 7.16e7.12 (2H, m), 4.99 (1H, d, J¼10.8 Hz), 4.83
(1H, d, J¼10.6 Hz), 4.82 (1H, d, J¼10.8 Hz), 4.77 (1H, d, J¼12.1 Hz),

7698
E. Kato et al. / Tetrahedron 67 (2011) 7692e7702
3.78e3.58 (11H, m), 3.55 (1H, dd, J¼3.7, 9.6 Hz), 3.42e3.37 (2H, m),
3.34 (1H, dd, J¼3.0, 14.2 Hz), 1.58 (2H, tt, J¼7.0, 7.0 Hz), 1.49 (2H, tt,
J¼6.5, 6.5 Hz), 1.34e1.23 (4H, m) ppm; 13C NMR (125 MHz, CDCl3,
rt): 155.7, 138.9, 138.32, 138.30, 138.25, 138.1, 137.9, 136.6, 128.37,
128.36, 128.34, 128.28, 127.93, 127.90, 127.85, 127.82, 127.79, 127.74,
127.70, 127.64, 127.59, 127.56, 127.50, 127.46, 96.8, 82.2, 82.1, 80.1,
78.6, 77.7, 75.6, 75.04, 75.01, 73.4, 73.0 (2C), 72.9, 71.6, 70.6, 70.1,
11.4 Hz), 3.79 (1H, dd, J¼2.0, 11.8 Hz), 3.75e3.70 (1H, m), 3.69e3.59
(4H, m), 3.55 (1H, ddd, J¼2.0, 5.5, 9.5 Hz), 3.48e3.42 (2H, m), 3.38
(1H, dd, J¼3.6, 9.5 Hz), 3.35 (1H, dd, J¼9.2, 9.2 Hz), 3.35e3.29 (1H,
m), 3.28 (1H, dd, J¼9.5, 9.5 Hz), 3.13e3.08 (1H, m), 2.86 (1H, dd,
J¼11.7,11.7 Hz), 1.68e1.56 (4H, m), 1.46e1.36 (4H, m) ppm; 13C NMR
(125 MHz, CD3OD, rt): 100.1, 81.4, 80.8, 75.1, 73.9, 73.7, 73.6, 73.1,
71.9, 69.0, 62.75, 62.67, 62.4, 51.0, 31.3, 30.6, 27.2, 27.0 ppm; ½a D26
ꢁ
68.5 (2C), 68.1, 67.1, 56.0, 41.5, 30.0, 29.3, 26.02, 25.95 ppm; ½a D27
ꢁ
þ59.6 (c 0.49, MeOH); HR-FAB-MS (negative): [MꢂH]ꢂ found m/z
424.2186, C18H34NOꢂ10 requires m/z 424.2183.
þ25.7 (c 0.60, CHCl3); HR-FD-MS (positive): fragment ion [MꢂH]þ
found m/z 1188.5818, C75H82NOþ12 requires m/z 1188.5837.
4.2.8.2. (2R,3R,4R,5S)-4,5-Dihydroxy-2-hydroxymethyl-3-[9-(a-D-
4.2.7.2. (2R,3R,4R,5S)-4,5-Dibenzyloxy-1-benzyloxycarbonyl-2-
benzyloxymethyl-3-[9-(2,3,4,6-tetra-O-benzyl-a-D-glucopyr-
glucopyranosyloxy)nonyloxy]piperidine hydrochloride (13b). Crystal,
yield 77%; 1H NMR (500 MHz, CD3OD, rt): 4.76 (1H, d, J¼3.6 Hz),
3.92 (1H, dt, J¼8.9, 6.7 Hz), 3.86 (1H, dd, J¼3.1,11.7 Hz), 3.82 (1H, dd,
J¼4.7, 11.7 Hz), 3.78 (1H, dd, J¼2.4, 11.9 Hz), 3.72 (1H, dt, J¼9.6,
6.8 Hz), 3.69e3.64 (2H, m), 3.63 (1H, dd, J¼9.1, 9.6 Hz), 3.60 (1H, dt,
J¼8.9, 6.7 Hz), 3.56 (1H, ddd, J¼2.4, 5.5, 9.9 Hz), 3.46 (1H, dd, J¼9.0,
9.0 Hz), 3.43 (1H, dt, J¼9.6, 6.5 Hz), 3.38 (1H, dd, J¼3.6, 9.6 Hz), 3.34
(1H, dd, J¼9.0, 10.2 Hz), 3.31 (1H, dt, J¼4.8, 11.9 Hz), 3.28 (1H, dd,
J¼9.1, 9.9 Hz), 3.09 (1H, ddd, J¼3.1, 4.7, 10.2 Hz), 2.84 (1H, dd, J¼11.9,
11.9 Hz), 1.68e1.54 (4H, m), 1.42e1.30 (10H, m) ppm; 13C NMR
(125 MHz, CD3OD, rt): 100.1, 78.4, 77.3, 75.1, 74.5, 73.62, 73.57, 71.8,
anosyloxy)nonyloxy] piperidine (12b). Oil, yield 34%; 1H NMR
(500 MHz, CDCl3, rt): 7.36e7.22 (38H, m), 7.17e7.11 (2H, m), 5.12
(1H, d, J¼12.4 Hz), 5.08 (1H, d, J¼12.4 Hz), 4.99 (1H, d, J¼10.9 Hz),
4.83 (1H, d, J¼10.9 Hz), 4.81 (1H, d, J¼10.9 Hz), 4.77 (1H, d,
J¼12.0 Hz), 4.76 (1H, d, J¼3.5 Hz), 4.68 (1H, d, J¼11.5 Hz), 4.66 (1H,
d, J¼11.5 Hz), 4.64 (1H, d, J¼12.0 Hz), 4.63 (1H, d, J¼11.5 Hz), 4.60
(1H, d, J¼12.2 Hz), 4.51 (1H, d, J¼12.0 Hz), 4.47 (1H, d, J¼10.9 Hz),
4.46 (1H, d, J¼12.2 Hz), 4.44 (1H, d, J¼11.5 Hz), 4.43 (1H, d,
J¼12.0 Hz), 4.10e4.05 (2H, m), 3.99 (1H, dd, J¼9.2, 9.4 Hz),
3.80e3.59 (11H, m), 3.56 (1H, dd, J¼3.5, 9.4 Hz), 3.45e3.39 (2H, m),
3.34 (1H, dd, J¼2.4, 14.6 Hz), 1.61 (2H, tt, J¼7.2, 7.2 Hz), 1.51e1.47
(2H, m), 1.34e1.20 (10H, m) ppm; 13C NMR (125 MHz, CDCl3, rt):
155.7, 138.9, 138.31, 138.30, 138.2, 138.1, 137.9, 136.6, 128.34, 128.32,
128.28, 128.25, 127.9, 127.84, 127.80, 127.76, 127.72, 127.69, 127.58,
127.53, 127.48, 127.46, 96.8, 82.3, 82.1, 80.1, 78.6, 77.8, 75.6, 75.0,
73.4, 73.0, 72.9, 71.7, 70.6, 70.0, 68.5, 68.2, 67.1, 56.0, 41.5, 30.0,
69.1, 68.8, 62.7, 61.1, 58.7, 47.4, 31.2, 30.6, 30.5, 27.3, 27.1 ppm; ½a D26
ꢁ
þ61.4 (c 0.33, MeOH); HR-FAB-MS (negative): [MꢂH]ꢂ found m/z
466.2641, C21H40NOꢂ10 requires m/z 466.2652.
4.2.8.3. (2R,3R,4R,5S)-4,5-Dihydroxy-2-hydroxymethyl-3-[12-(a-D-
glucopyranosyloxy)dodecyloxy]piperidine hydrochloride (13c). Crystal,
yield 78%; 1H NMR (500 MHz, CD3OD, rt): 4.76 (1H, d, J¼3.6 Hz), 3.92
(1H, dt, J¼9.0, 6.4 Hz), 3.86 (1H, dd, J¼2.4, 12.0 Hz), 3.82 (1H, dd,
J¼4.2, 12.0 Hz), 3.78 (1H, dd, J¼2.3, 11.8 Hz), 3.71 (1H, dt, J¼9.5,
6.9 Hz), 3.70e3.64 (2H, m), 3.63 (1H, dd, J¼9.6, 9.7 Hz), 3.62e3.58
(1H, m), 3.56 (1H, ddd, J¼2.4, 5.5, 9.6 Hz), 3.46 (1H, dd, J¼9.2, 9.2 Hz),
3.43 (1H, dt, J¼9.7, 6.4 Hz), 3.38 (1H, dd, J¼3.6, 9.7 Hz), 3.34 (1H, dd,
J¼9.2, 10.0 Hz), 3.31 (1H, dt, J¼4.8, 11.8 Hz), 3.28 (1H, dd, J¼9.6,
9.6 Hz), 3.11e3.07 (1H, m), 2.84 (1H, dd, J¼11.8, 11.8 Hz), 1.66e1.53
(4H, m), 1.42e1.26 (16H, m) ppm; 13C NMR (125 MHz, CD3OD, rt):
100.1, 78.4, 77.3, 75.1, 74.6, 73.60, 73.57, 71.8, 69.1, 68.8, 62.7, 61.1, 58.7,
29.48, 29.45, 29.40, 29.38, 26.12, 26.06 ppm; ½a D27
þ23.6 (c 0.52,
ꢁ
CHCl3); HR-FD-MS (positive): fragment ion [MꢂH]þ found m/z
1230.6293, C78H88NOþ12 requires m/z 1230.6307.
4.2.7.3. (2R,3R,4R,5S)-4,5-Dibenzyloxy-1-benzyloxycarbonyl-2-
benzyloxymethyl-3-[12-(2,3,4,6-tetra-O-benzyl-a-D-glucopyr-
anosyloxy)dodecyloxy] piperidine (12c). Oil, yield 31%; 1H NMR
(500 MHz, CDCl3, rt): 7.36e7.24 (38H, m), 7.14e7.12 (2H, m), 5.12
(1H, d, J¼12.4 Hz), 5.09 (1H, d, J¼12.4 Hz), 4.99 (1H, d, J¼10.9 Hz),
4.83 (1H, d, J¼10.8 Hz), 4.81 (1H, d, J¼10.9 Hz), 4.77 (1H, d,
J¼12.1 Hz), 4.76 (1H, d, J¼3.5 Hz), 4.68 (1H, d, J¼11.5 Hz), 4.65 (1H,
d, J¼12.0 Hz), 4.64 (1H, d, J¼12.1 Hz), 4.63 (1H, d, J¼11.5 Hz), 4.60
(1H, d, J¼12.1 Hz), 4.51 (1H, d, J¼12.0 Hz), 4.47 (1H, d, J¼10.8 Hz),
4.46 (1H, d, J¼12.1 Hz), 4.44 (1H, d, J¼12.0 Hz), 4.43 (1H, d,
J¼12.0 Hz), 4.10e4.05 (2H, m), 3.99 (1H, dd, J¼9.3, 9.6 Hz),
3.80e3.59 (11H, m), 3.55 (1H, dd, J¼3.5, 9.6 Hz), 3.44e3.39 (2H, m),
3.34 (1H, dd, J¼3.5, 14.2 Hz), 1.62 (2H, tt, J¼7.2, 7.2 Hz), 1.51e1.46
(2H, m), 1.37e1.20 (16H, m) ppm; 13C NMR (125 MHz, CDCl3, rt):
155.7, 138.9, 138.34, 138.32, 138.26, 138.1, 137.9, 136.6, 128.36,
128.33, 128.29, 128.27, 127.9, 127.846, 127.81, 127.77, 127.72, 127.71,
127.61, 127.58, 127.54, 127.49, 127.47, 96.8, 82.3, 82.1, 80.1, 78.6, 77.8,
75.6, 75.0, 73.4, 73.0, 72.9, 71.7, 70.6, 70.1, 68.5, 68.2, 67.1, 56.0, 41.5,
47.4, 31.2, 30.7, 30.61, 30.56, 27.3, 27.1 ppm; ½a D27
þ67.1 (c 0.17,
ꢁ
MeOH); HR-FAB-MS (negative): [MꢂH]ꢂ found m/z 508.3136,
C24H46NOꢂ10 requires m/z 508.3122.
4 . 2 . 9 . S y n t h e s i s o f 2 , 3 , 4 , 6 - t e t ra - O - b e n z yl - 1 - O - ( 15 -
hydroxypentadecyl)-
a-D
-glucopyranose
(14). Compound
9
(204.9 mg, 0.379 mmol) was dissolved in CH2Cl2 (4 mL) and Ph3P
(294.9 mg, 1.12 mmol), CBr4 (374.3 mg, 1.13 mmol) was added. After
stirring for 4 h, THF (4 mL) solution of TMU (272 mL, 2.27 mmol), 15-
hydroxypentadecanol (180.6 mg, 0.74 mmol), and TEAB (95.7 mg,
0.455 mmol) was added and further stirred for 12 h. The reaction
mixture was diluted with 1 M HCl aq and extracted by EtOAc. The
organic layer was washed with satd NaHCO3 aq and brine, dried
over sodium sulfate, evaporated and purified by silica-gel column
chromatography (hexane/EtOAc¼9/1 to 3/1) to give 14 (123.6 mg,
43%) as an oil.
30.0, 29.6, 29.58, 29.56, 29.49, 29.44, 29.38, 26.14, 26.08 ppm; ½a D27
ꢁ
þ23.4 (c 0.48, CHCl3); HR-FD-MS (positive): fragment ion [MꢂH]þ
found m/z 1272.6795, C81H94NOþ12 requires m/z 1272.6776.
1H NMR (500 MHz, CDCl3, rt): 7.36e7.22 (18H, m), 7.15e7.12 (2H,
m), 4.99 (1H, d, J¼10.8 Hz), 4.83 (1H, d, J¼10.8 Hz), 4.81 (1H, d,
J¼10.8 Hz), 4.76 (1H, d, J¼12.1 Hz), 4.76 (1H, d, J¼3.7 Hz), 4.64 (1H,
d, J¼12.1 Hz), 4.59 (1H, d, J¼12.1 Hz), 4.47 (1H, d, J¼10.8 Hz), 4.45
(1H, d, J¼12.1 Hz), 4.00 (1H, dd, J¼9.2, 9.2 Hz), 3.79 (1H, ddd, J¼1.9,
3.6, 9.9 Hz), 3.72 (1H, dd, J¼3.6, 10.7 Hz), 3.66e3.60 (3H, m), 3.56
(1H, dd, J¼3.7, 9.2 Hz), 3.55 (2H, t, J¼6.7 Hz), 3.42 (1H, dt, J¼9.8,
6.7 Hz), 1.63 (2H, tt, J¼6.7, 7.0 Hz), 1.51 (2H, tt, J¼6.7, 6.7 Hz),
1.38e1.24 (22H, m) ppm; 13C NMR (125 MHz, CDCl3, rt): 138.8,
138.2, 138.1, 137.8, 128.2, 128.1, 127.8, 127.72, 127.69, 127.6, 127.5,
127.3, 96.7, 81.9, 80.0, 77.7, 75.5, 74.9, 73.3, 72.9, 69.9, 68.4, 68.1,
62.6, 32.6, 29.48, 29.45, 29.43, 29.40, 29.27, 29.23, 26.0, 25.9 ppm;
4.2.8. General procedure for the synthesis of 13. Compound 12 was
dissolved in EtOH/THF (2/1) and acidified by 1 M HCl aq to pH 2. To
this solution Pd(OH)2 was added and stirred under hydrogen at-
mosphere. After 15 h, the reaction mixture was passed through
Celite pad, evaporated, and purified by LiCholut RP-18 (Merck Co.)
to give 13.
4.2.8.1. (2R,3R,4R,5S)-4,5-Dihydroxy-2-hydroxymethyl-3-[6-(a-D-
glucopyranosyloxy)hexyloxy]piperidine hydrochloride (13a). Crystal,
yield 89%; 1H NMR (500 MHz, CD3OD, rt): 4.76 (1H, d, J¼3.6 Hz),
3.95e3.90 (1H, m), 3.88 (1H, br d, J¼11.4 Hz), 3.83 (1H, dd, J¼3.7,

E. Kato et al. / Tetrahedron 67 (2011) 7692e7702
7699
½
a 2D7
ꢁ
þ31.1 (c 1.00, CHCl3); HR-FD-MS (positive): fragment ion
3.68e3.59 (4H, m), 3.56 (1H, ddd, J¼2.1, 5.5, 9.6 Hz), 3.45 (1H, dd,
J¼9.0, 9.0 Hz), 3.45e3.40 (1H, m), 3.38 (1H, dd, J¼3.6, 9.6 Hz), 3.33
(1H, dd, J¼9.0, 10.2 Hz), 3.33e3.28 (1H, m), 3.28 (1H, dd, J¼9.6,
9.6 Hz), 3.08 (1H, ddd, J¼3.1, 4.6, 10.2 Hz), 2.84 (1H, dd, J¼12.0,
12.0 Hz), 1.67e1.53 (4H, m), 1.42e1.26 (22H, m) ppm 13C NMR
(125 MHz, CD3OD, rt): 100.1, 78.4, 77.3, 75.1, 74.6, 73.6, 73.5, 71.8,
69.1, 68.8, 62.7, 61.0, 58.7, 47.3, 31.2, 30.71, 30.68, 30.61, 30.58,
[MꢂH]þ found m/z 765.4725, C49H65Oþ7 requires m/z 765.4730.
4.2.10. Synthesis of 2,3,4,6-tetra-O-benzyl-1-O-(15-iodopentadecyl)-
a-D-glucopyranose (15). Compound 14 (123.6 mg, 0.161 mmol) was
dissolved in CH2Cl2 (3 mL) and Ph3P (52.6 mg, 0.201 mmol), im-
idazole (16.6 mg, 0.244 mmol), N-iodosuccinimide (60.7 mg,
0.270 mmol) was added. After stirring for an hour, the reaction
mixture was evaporated and the residue was purified by silica-gel
column chromatography (hexane/EtOAc¼9/1 to 4/1) to give 15
(86.2 mg, 61%) as an oil.
27.3, 27.1 ppm; ½a D26
þ49.9 (c 0.63, MeOH); HR-FAB-MS (nega-
ꢁ
tive): [MꢂH]ꢂ found m/z 550.3555, C27H52NO1ꢂ0 requires m/z
550.3591.
1H NMR (500 MHz, CDCl3, rt): 7.36e7.24 (18H, m), 7.16e7.12 (2H,
m), 4.99 (1H, d, J¼10.7 Hz), 4.83 (1H, d, J¼10.7 Hz), 4.81 (1H, d,
J¼10.7 Hz), 4.77 (1H, d, J¼12.0 Hz), 4.76 (1H, d, J¼3.6 Hz), 4.65 (1H,
d, J¼12.0 Hz), 4.60 (1H, d, J¼12.1 Hz), 4.47 (1H, d, J¼10.7 Hz), 4.46
(1H, d, J¼12.1 Hz), 3.99 (1H, dd, J¼9.3, 9.5 Hz), 3.78 (1H, ddd, J¼2.0,
3.6, 10.0 Hz), 3.72 (1H, dd, J¼3.6, 10.5 Hz), 3.65e3.60 (3H, m), 3.55
(1H, dd, J¼3.6, 9.5 Hz), 3.42 (1H, dt, J¼9.7, 6.8 Hz), 3.16 (2H, t,
J¼7.1 Hz), 1.80 (2H, tt, J¼7.1, 7.1 Hz), 1.62 (2H, tt, J¼6.8, 6.8 Hz),
1.39e1.24 (22H, m) ppm 13C NMR (125 MHz, CDCl3, rt): 138.9, 138.3,
138.2, 137.9, 128.30, 128.26, 127.92, 127.83, 127.78, 127.69, 127.56,
127.55, 127.42, 96.8, 82.1, 80.1, 77.8, 75.6, 75.0, 73.4, 73.0, 70.0, 68.5,
68.2, 33.5, 30.4, 29.58, 29.56, 29.54, 29.49, 29.47, 29.37, 29.34, 28.5,
4.2.13. General procedure for the synthesis of 18. Compound 17
(1.5 equiv) and 11 (1 equiv) were dissolved in DMF and NaH
(4 equiv) was added. The mixture was stirred for 15 h under argon
atmosphere and then satd NH4Cl aq was added and extracted by
EtOAc. Organic layer was washed with brine, dried over sodium
sulfate, and evaporated. The residue was purified by silica-gel col-
umn chromatography to give 18.
4.2.13.1. (2R,3R,4R,5S)-4,5-Dibenzyloxy-1-benzyloxycarbonyl-2-
benzyloxymethyl-3-[4-(p-methoxybenzyloxy)butyloxy]piperidine
(18e). Oil, yield 30%; 1H NMR (270 MHz, CDCl3, rt): 7.34e7.25 (22H,
m), 6.86 (2H, d, J¼8.6 Hz), 5.13 (1H, d, J¼12.4 Hz), 5.07 (1H, d,
J¼12.4 Hz), 4.66 (1H, d, J¼11.6 Hz), 4.64 (1H, d, J¼11.6 Hz), 4.61 (1H,
d, J¼11.6 Hz), 4.50 (1H, d, J¼12.0 Hz), 4.43 (1H, d, J¼11.6 Hz), 4.41
(1H, d, J¼12.0 Hz), 4.38 (2H, s), 4.10e4.04 (2H, m), 3.78 (3H, s),
3.76e3.62 (6H, m), 3.46e3.29 (4H, m), 1.63e1.54 (4H, m) ppm; 13C
NMR (67.5 MHz, CDCl3, rt): 159.0, 155.7, 138.3, 138.0, 136.6, 130.7,
129.2, 128.4, 128.3, 127.86, 127.82, 127.76, 127.64, 127.60, 127.54,
127.51, 113.7, 82.1, 78.6, 75.0, 73.0, 72.9, 72.5, 71.4, 70.6, 69.8, 68.5,
26.1, 7.2 ppm; ½a D27
þ25.3 (c 1.00, CHCl3); HR-FD-MS (positive):
ꢁ
fragment ion [MꢂH]þ found m/z 875.3770, C49H64IOþ6 requires m/z
875.3748.
4. 2.11. Synthesis of (2R, 3R, 4R, 5S)-4, 5-dibenzyloxy-1-
benzyloxycarbonyl-2-benzyloxymethyl-3-[15-(2,3,4,6-tetra-O-benzyl-
a-D-glucopyranosyloxy)pentadecyloxy] piperidine (16). Compounds
15 (441.8 mg, 0.503 mmol) and 11 (224.1 mg, 0.395 mmol) were
dissolved in dry THF. The solution was cooled to 0 ꢀC and NaH
(21.4 mg, 0.892 mmol) was added and stirred under argon atmo-
sphere. After 17 h, water was added and the solution was extracted
by EtOAc. Organic layer was washed with brine, dried over sodium
sulfate, and evaporated. The residue was purified by silica-gel col-
umn chromatography (hexane/EtOAc¼4/1) to give 16 (62.8 mg,12%)
as an oil.
67.2, 56.0, 55.2, 41.4, 26.8, 26.4 ppm; ½a D27
þ13.6 (c 2.00, CHCl3); HR-
ꢁ
FD-MS (positive): [M]þ found m/z 759.3785, C47H53NOþ8 requires m/
z 759.3771.
4.2.13.2. (2R,3R,4R,5S)-4,5-Dibenzyloxy-1-benzyloxycarbonyl-2-
benzyloxymethyl-3-[5-(p-methoxybenzyloxy)pentyloxy] piperidine
(18f). Oil, yield 46%; 1H NMR (270 MHz, CDCl3, rt): 7.33e7.21
(22H, m), 6.85 (2H, d, J¼8.6 Hz), 5.13 (1H, d, J¼12.5 Hz), 5.08 (1H,
d, J¼12.5 Hz), 4.67 (1H, d, J¼11.6 Hz), 4.64 (1H, d, J¼11.7 Hz), 4.62
(1H, d, J¼11.6 Hz), 4.50 (1H, d, J¼12.1 Hz), 4.43 (1H, d, J¼11.7 Hz),
4.42 (1H, d, J¼12.1 Hz), 4.40 (2H, s), 4.12e4.05 (2H, m), 3.76 (3H,
s), 3.76e3.63 (6H, m), 3.46e3.29 (4H, m), 1.61e1.45 (4H, m),
1.38e1.29 (2H, m) ppm; 13C NMR (67.5 MHz, CDCl3, rt): 159.0,
155.7, 138.24, 138.21, 138.0, 136.6, 130.7, 129.1, 128.3, 128.2, 127.80,
127.76, 127.69, 127.62, 127.58, 127.53, 127.48, 127.47, 113.7, 82.1,
78.5, 74.9, 73.0, 72.9, 72.4, 71.5, 70.5, 69.9, 68.5, 67.1, 55.9, 55.2,
1H NMR (500 MHz, CDCl3, rt): 7.36e7.24 (38H, m), 7.14e7.12 (2H,
m), 5.12 (1H, d, J¼12.4 Hz), 5.09 (1H, d, J¼12.4 Hz), 4.99 (1H, d,
J¼10.8 Hz), 4.83 (1H, d, J¼10.7 Hz), 4.81 (1H, d, J¼10.8 Hz), 4.77 (1H,
d, J¼12.0 Hz), 4.76 (1H, d, J¼3.6 Hz), 4.68 (1H, d, J¼11.6 Hz), 4.65
(1H, d, J¼11.7 Hz), 4.64 (1H, d, J¼12.0 Hz), 4.63 (1H, d, J¼11.6 Hz),
4.60 (1H, d, J¼12.2 Hz), 4.51 (1H, d, J¼12.0 Hz), 4.47 (1H, d,
J¼10.7 Hz), 4.46 (1H, d, J¼12.2 Hz), 4.44 (1H, d, J¼11.7 Hz), 4.43 (1H,
d, J¼12.0 Hz), 4.11e4.05 (2H, m), 3.99 (1H, dd, J¼9.3, 9.6 Hz),
3.80e3.59 (11H, m), 3.56 (1H, dd, J¼3.6, 9.6 Hz), 3.44e3.39 (2H, m),
3.34 (1H, dd, J¼3.2, 14.3 Hz), 1.66e1.59 (2H, m), 1.53e1.46 (2H, m),
1.40e1.20 (22H, m) ppm 13C NMR (125 MHz, CDCl3, rt): 172.4, 155.7,
138.9, 138.31, 138.29, 138.23, 138.1, 137.9, 136.6, 128.35, 128.32,
128.29, 128.26, 128.0, 127.85, 127.81, 127.77, 127.73, 127.71, 127.65,
127.6, 127.53, 127.48, 127.46, 96.8, 82.3, 82.1, 80.1, 78.6, 77.7, 75.6,
75.00, 74.97, 73.4, 73.0, 72.9, 71.7, 70.6, 70.0, 68.5, 68.2, 67.1, 56.0,
41.4, 30.0, 29.65, 29.62, 29.58, 29.55, 29.47, 29.41, 29.35, 26.12,
41.4, 29.8, 29.5, 22.7 ppm; ½a D27
þ11.9 (c 1.00, CHCl3); HR-FD-MS
ꢁ
(positive): [M]þ found m/z 773.3922, C48H55NOþ8 requires m/z
773.3928.
4.2.14. General procedure for the synthesis of 19. Compound 18 was
dissolved in 10% TFA/CH2Cl2 and stirred for 2 h. The reaction
mixture was evaporated and the residue was purified by PTLC to
give 19.
26.06 ppm; ½a 2D7
þ21.3 (c 0.75, CHCl3); HR-FD-MS (positive): frag-
ꢁ
ment ion [MꢂH]þ found m/z 1314.7247, C84H100NO1þ2 requires m/z
4.2.14.1. (2R,3R,4R,5S)-4,5-Dibenzyloxy-1-benzyloxycarbonyl-2-
benzyloxymethyl-3-(4-hydroxybutyloxy)piperidine (19e). Oil, yield
66%; 1H NMR (270 MHz, CDCl3, rt): 7.34e7.23 (20H, m), 5.15 (1H, d,
J¼12.4 Hz), 5.09 (1H, d, J¼12.4 Hz), 4.63 (1H, d, J¼11.9 Hz), 4.64 (1H,
d, J¼11.8 Hz), 4.58 (1H, d, J¼11.9 Hz), 4.52 (1H, d, J¼12.0 Hz), 4.42
(1H, d, J¼11.8 Hz), 4.42 (1H, d, J¼12.0 Hz), 4.24 (1H, dd, J¼4.7,
9.0 Hz), 4.14 (1H, br d, J¼14.4 Hz), 3.74e3.59 (6H, m), 3.55e3.44
(3H, m), 3.28 (1H, dd, J¼3.0, 14.4 Hz), 1.61e1.50 (4H, m) ppm; 13C
NMR (67.5 MHz, CDCl3, rt): 155.8, 138.1, 138.0, 137.9, 136.6, 128.33,
128.28, 128.25, 128.23, 127.80, 127.78, 127.73, 127.59, 127.52, 127.50,
80.5, 76.95, 74.7, 72.9, 72.7, 71.1, 70.4, 68.1, 67.1, 62.2, 55.1, 40.4, 29.7,
1314.7246.
4.2.12. Synthesis of (2R,3R,4R,5S)-4,5-dihydroxy-2-hydroxymethyl-
3-[15-(a-D-glucopyranosyloxy)pentadecyloxy]piperidine hydrochlo-
ride (13d). Protective groups of 16 (51.7 mg, 0.0393 mmol) was
removed by the method written in Section 4.2.8 to give 13d
(19.4 mg, 74%) as a crystal.
1H NMR (500 MHz, CD3OD, rt): 4.76 (1H, d, J¼3.6 Hz), 3.92 (1H,
dt, J¼8.9, 6.6 Hz), 3.85 (1H, dd, J¼3.1, 11.8 Hz), 3.81 (1H, dd, J¼4.6,
11.8 Hz), 3.78 (1H, dd, J¼2.1, 12.0 Hz), 3.72 (1H, dt, J¼9.6, 7.0 Hz),

7700
E. Kato et al. / Tetrahedron 67 (2011) 7692e7702
26.4 ppm; ½a 2D7
ꢁ
þ10.3 (c 1.00, CHCl3); HR-FD-MS (positive): [M]þ
4.2.16. Synthesis of 13e,f. Protective groups of 20 was removed by
the method written in Section 4.2.8 to give 13e or 13f.
found m/z 639.3193, C39H45NOþ7 requires m/z 639.3196.
4.2.14.2. (2R,3R,4R,5S)-4,5-Dibenzyloxy-1-benzyloxycarbonyl-2-
benzyloxymethyl-3-(5-hydroxypentyloxy)piperidine (19f). Oil, yield
quant.; 1H NMR (270 MHz, CDCl3, rt): 7.40e7.23 (20H, m), 5.11 (2H, s),
4.66 (1H, d, J¼11.8 Hz), 4.64 (1H, d, J¼11.8 Hz), 4.62 (1H, d, J¼11.8 Hz),
4.52 (1H, d, J¼12.0 Hz), 4.44 (1H, d, J¼11.8 Hz), 4.43 (1H, d, J¼12.0 Hz),
4.17e4.04 (2H, m), 3.76e3.61 (6H, m), 3.55 (2H, t, J¼6.5 Hz), 3.43 (1H,
td, J¼6.5, 9.0 Hz), 3.33 (1H, dd, J¼2.8, 14.5 Hz), 1.62e1.45 (4H, m),
1.38e1.25 (2H, m) ppm; 13C NMR (67.5 MHz, CDCl3, rt): 155.8, 138.2,
138.0, 136.6, 128.4, 128.3, 127.9, 127.8, 127.7, 127.6, 127.5, 81.6, 78.1,
74.9, 73.0, 72.8, 71.3, 70.6, 68.4, 67.2, 62.7, 55.7, 41.2, 32.4, 29.6,
4.2.16.1. (2R,3R,4R,5S)-4,5-Dihydroxy-2-hydroxymethyl-3-[4-(a-D-
glucopyranosyloxy)butyloxy]piperidine hydrochloride (13e). Crystal,
yield 81%; 1H NMR (500 MHz, CD3OD, rt): 4.77 (1H, d, J¼3.6 Hz),
4.00e3.90 (1H, m), 3.86 (1H, br d, J¼11.6 Hz), 3.83 (1H, br d,
J¼11.6 Hz), 3.79 (1H, dd, J¼2.0, 11.8 Hz), 3.78e3.74 (1H, m),
3.69e3.63 (3H, m), 3.62 (1H, dd, J¼9.3, 9.6 Hz), 3.56 (1H, ddd, J¼2.0,
5.5, 9.5 Hz), 3.49e3.43 (2H, m), 3.38 (1H, dd, J¼3.6, 9.6 Hz),
3.37e3.34 (1H, m), 3.33e3.28 (1H, m), 3.27 (1H, dd, J¼9.3, 9.5 Hz),
3.12e3.07 (1H, m), 2.84 (1H, dd, J¼11.8, 11.8 Hz), 1.74e1.68 (4H, m)
ppm; 13C NMR (125 MHz, CD3OD, rt): 100.1, 78.4, 77.2, 75.1, 74.2, 73.7,
22.3 ppm; ½a 2D7
ꢁ
þ7.2 (c 0.27, CHCl3); HR-FD-MS (positive): [M]þ found
73.5, 71.9, 68.84, 68.78, 62.8, 61.0, 58.7, 47.4, 28.0, 27.2 ppm; ½a D26
ꢁ
m/z 653.3339, C40H47NOþ7 requires m/z 653.3353.
þ59.4 (c 0.14, MeOH); HR-FAB-MS (positive): [MþH]þ found m/z
398.2005, C16H32NOþ10 requires m/z 398.2026.
4.2.15. General procedure for the synthesis of 20. Compound 9
(1 equiv) was dissolved in CH2Cl2 and Ph3P (1.1 equiv), CBr4
(1.2 equiv) was added. After stirring for 14 h at rt, CH2Cl2 solution of
19 (0.68 equiv), TMU (1.6 equiv) and TEAB (1 equiv) was added and
further stirred for 20 h at 40 ꢀC. The reaction mixture was diluted
with water and extracted by CHCl3. The organic layer was dried
over sodium sulfate, evaporated, and purified by silica-gel column
chromatography to give 20.
4.2.16.2. (2R,3R,4R,5S)-4,5-Dihydroxy-2-hydroxymethyl-3-[5-(a-D-
glucopyranosyloxy)pentyloxy]piperidine hydrochloride (13f). Crystal,
yield 85%; 1H NMR (500 MHz, CD3OD, rt): 4.76 (1H, d, J¼3.8 Hz),
3.94 (1H, td, J¼6.3, 9.0 Hz), 3.85 (1H, dd, J¼3.2, 11.7 Hz), 3.82 (1H,
dd, J¼4.6, 11.7 Hz), 3.79 (1H, dd, J¼2.2, 11.8 Hz), 3.74 (1H, td, J¼6.6,
9.5 Hz), 3.68e3.60 (4H, m), 3.57 (1H, ddd, J¼2.2, 5.7, 9.8 Hz), 3.46
(1H, dd, J¼9.0, 9.0 Hz), 3.45 (1H, td, J¼6.2, 9.5 Hz), 3.38 (1H, dd,
J¼3.8, 9.8 Hz), 3.28 (1H, dd, J¼9.0, 10.3 Hz), 3.32e3.28 (1H, m), 3.27
(1H, dd, J¼8.9, 9.8 Hz), 3.09 (1H, ddd, J¼3.2, 4.6, 10.3 Hz), 2.84 (1H,
dd, J¼11.9, 11.9 Hz), 1.72e1.58 (4H, m), 1.57e1.41 (2H, m) ppm; 13C
NMR (125 MHz, CD3OD, rt): 100.0, 78.4, 77.3, 75.1, 74.4, 73.7, 73.6,
4.2.15.1. (2R,3R,4R,5S)-4,5-Dibenzyloxy-1-benzyloxycarbonyl-2-
benzyloxymethyl-3-[4-(2,3,4,6-tetra-O-benzyl-a-D-glucopyr-
anosyloxy)butyloxy] piperidine (20e). Oil, yield 46%; 1H NMR
(500 MHz, CDCl3, rt): 7.35e7.22 (38H, m), 7.14e7.12 (2H, m), 5.12
(1H, d, J¼12.5 Hz), 5.08 (1H, d, J¼12.5 Hz), 4.96 (1H, d, J¼10.8 Hz),
4.82 (1H, d, J¼10.8 Hz), 4.79 (1H, d, J¼10.8 Hz), 4.74 (1H, d,
J¼12.1 Hz), 4.73 (1H, d, J¼3.5 Hz), 4.65 (1H, d, J¼11.6 Hz), 4.63 (1H,
d, J¼11.5 Hz), 4.62 (1H, d, J¼12.1 Hz), 4.61 (1H, d, J¼11.6 Hz), 4.59
(1H, d, J¼12.2 Hz), 4.49 (1H, d, J¼12.4 Hz), 4.46 (1H, d, J¼10.8 Hz),
4.44 (1H, d, J¼12.2 Hz), 4.43 (1H, d, J¼11.5 Hz), 4.42 (1H, d,
J¼12.4 Hz), 4.10e4.05 (2H, m), 3.96 (1H, dd, J¼9.0, 9.6 Hz),
3.75e3.57 (11H, m), 3.54 (1H, dd, J¼3.5, 9.6 Hz), 3.45e3.39 (1H, m),
3.37e3.32 (1H, m), 3.33 (1H, dd, J¼3.0, 14.4 Hz), 1.64e1.52 (4H, m)
ppm; 13C NMR (67.5 MHz, CDCl3, rt): 155.7, 138.8, 138.27, 138.22,
138.0, 137.9, 136.6, 128.36, 128.35, 128.30, 127.95, 127.87, 127.85,
127.80, 127.76, 127.73, 127.61, 127.52, 127.49, 127.47, 96.9, 82.10,
82.06, 80.0, 78.5, 77.6, 75.6, 75.0, 73.4, 73.0, 72.9, 71.3, 70.5, 70.1,
71.9, 68.89, 68.84, 62.8, 61.0, 58.8, 47.3, 30.9, 30.3, 23.9 ppm; ½a D26
ꢁ
þ65.4 (c 0.25, MeOH); HR-FAB-MS (negative): [MꢂH]ꢂ found m/z
410.2005, C17H32NOꢂ10 requires m/z 410.2026.
4.2.17. General procedure for the synthesis of 22aec. Compounds 21
(2 equiv) and 11 (1 equiv) were dissolved in THF/DMF (1/1) and TBAI
(1 equiv), NaH (4 equiv) was added. After stirring for 12 h, satd NH4Cl
aq was added and extracted by EtOAc. The organic layer was washed
with brine, dried over sodium sulfate, and evaporated. The residue
was purified by silica-gel column chromatography to give 22aec.
4.2.17.1. (2R,3R,4R,5S)-4,5-Dibenzyloxy-1-benzyloxycarbonyl-2-
benzyloxymethyl-3-[6-(tetrahydropyran-2-yloxy)hexyloxy]
piperi-
dine (22a). Oil, yield 64%; 1H NMR (270 MHz, CD3OD, rt): 7.35e7.23
(20H, m), 5.13 (1H, d, J¼12.5 Hz), 5.08 (1H, d, J¼12.5 Hz), 4.68 (1H, d,
J¼11.5 Hz), 4.64 (1H, d, J¼11.8 Hz), 4.62 (1H, d, J¼11.5 Hz), 4.55 (1H,
dd, J¼2.8, 4.2 Hz), 4.52 (1H, d, J¼11.9 Hz), 4.44 (1H, d, J¼11.8 Hz),
4.42 (1H, d, J¼11.9 Hz), 4.12e4.05 (2H, m), 3.85 (1H, ddd, J¼3.9, 7.0,
11.0 Hz), 3.77e3.61 (7H, m), 3.52e3.30 (4H, m), 1.87e1.42 (10H, m),
1.42e1.21 (6H, m) ppm; 13C NMR (67.5 MHz, CD3OD, rt): 155.6,
138.22, 138.18, 138.0, 136.6, 128.3, 128.2, 127.76, 127.72, 127.65,
127.54, 127.49, 127.43, 126.50, 98.7, 82.1, 78.5, 74.9, 73.0, 72.9, 71.6,
70.5, 68.4, 67.4, 67.1, 62.2, 55.9, 41.4, 30.7, 29.9, 29.6, 26.0, 25.9, 25.4,
68.5, 68.4, 67.9, 67.1, 55.9, 41.3, 26.8, 26.2 ppm; ½a D27
þ16.5 (c 0.19,
ꢁ
CHCl3); HR-FD-MS (positive): [M]þ found m/z 1161.5569,
C73H79NOþ12 requires m/z 1161.5602.
4.2.15.2. (2R,3R,4R,5S)-4,5-Dibenzyloxy-1-benzyloxycarbonyl-2-
benzyloxymethyl-3-[5-(2,3,4,6-tetra-O-benzyl-a-D-glucopyr-
anosyloxy)pentyloxy] piperidine (20f). Oil, yield 59%; 1H NMR
(500 MHz, CDCl3, rt): 7.36e7.22 (38H, m), 7.16e7.11 (2H, m), 5.12
(1H, d, J¼12.3 Hz), 5.08 (1H, d, J¼12.3 Hz), 4.97 (1H, d, J¼10.9 Hz),
4.82 (1H, d, J¼10.8 Hz), 4.79 (1H, d, J¼10.9 Hz), 4.76 (1H, d,
J¼12.1 Hz), 4.73 (1H, d, J¼3.6 Hz), 4.66 (1H, d, J¼11.7 Hz), 4.64
(1H, d, J¼11.7 Hz), 4.63 (1H, d, J¼12.1 Hz), 4.62 (1H, d, J¼11.7 Hz),
4.59 (1H, d, J¼12.1 Hz), 4.50 (1H, d, J¼12.1 Hz), 4.46 (1H, d,
J¼10.8 Hz), 4.45 (1H, d, J¼12.1 Hz), 4.44 (1H, d, J¼11.7 Hz), 4.42
(1H, d, J¼12.1 Hz), 4.10e4.04 (2H, m), 3.97 (1H, dd, J¼9.3, 9.3 Hz),
3.76e3.56 (11H, m), 3.54 (1H, dd, J¼3.6, 9.6 Hz), 3.44e3.33 (2H,
m), 3.33 (1H, dd, J¼2.7, 14.5 Hz), 1.62e1.46 (4H, m), 1.37e1.24 (2H,
m) ppm; 13C NMR (67.5 MHz, CDCl3, rt): 155.7, 138.9, 138.8,
138.32, 138.29, 138.25, 138.1, 137.9, 136.6, 128.4, 128.3, 128.0,
127.93, 127.90, 127.84, 127.76, 127.6, 127.5, 96.9, 82.2, 82.1, 80.0,
78.6, 77.7, 75.7, 75.1, 75.0, 73.5, 73.10, 73.07, 72.96, 71.5, 70.6, 70.1,
19.6 ppm; ½a 2D7
ꢁ
þ6.7 (c 0.51, CHCl3); HR-FD-MS (positive): [M]þ
found m/z 751.4073, C46H57NOþ8 requires m/z 751.4084.
4.2.17.2. (2R,3R,4R,5S)-4,5-Dibenzyloxy-1-benzyloxycarbonyl-2-
benzyloxymethyl-3-[9-(tetrahydropyran-2-yloxy)nonyloxy] piperi-
dine (22b). Oil, yield 29%; 1H NMR (270 MHz, CD3OD, rt): 7.35e7.23
(20H, m), 5.13 (1H, d, J¼12.4 Hz), 5.08 (1H, d, J¼12.4 Hz), 4.68 (1H, d,
J¼11.5 Hz), 4.64 (1H, d, J¼11.8 Hz), 4.63 (1H, d, J¼11.5 Hz), 4.57 (1H,
dd, J¼2.8, 4.3 Hz), 4.52 (1H, d, J¼12.0 Hz), 4.44 (1H, d, J¼11.8 Hz),
4.43 (1H, d, J¼12.0 Hz), 4.16e4.04 (2H, m), 3.87 (1H, ddd, J¼3.7, 7.0,
10.9 Hz), 3.78e3.61 (7H, m), 3.54e3.30 (4H, m), 1.88e1.41 (10H, m),
1.41e1.20 (10H, m) ppm; 13C NMR (67.5 MHz, CD3OD, rt): 155.7,
138.3, 138.2, 138.0, 136.6, 128.4, 128.3, 127.82, 127.79, 127.7, 127.61,
127.55, 127.50, 127.47, 98.8, 82.3, 78.7, 74.9, 73.02, 72.96, 71.8, 70.6,
68.5, 67.6, 67.1, 62.3, 56.0, 41.5, 30.7, 30.0, 29.7, 29.5, 29.4, 26.2, 26.0,
68.51, 68.46, 68.1, 67.2, 56.0, 41.5, 29.9, 29.3, 22.6 ppm; ½a D27
þ24.6
ꢁ
(c 0.54, CHCl3); HR-FD-MS (positive): [M]þ found m/z 1175.5759,
C74H81NOþ12 requires m/z 1175.5759.

E. Kato et al. / Tetrahedron 67 (2011) 7692e7702
7701
25.4, 19.6 ppm; ½a D27
ꢁ
þ5.6 (c 1.00, CHCl3); HR-FD-MS (positive):
J¼5.1, 12.4 Hz), 3.08 (1H, ddd, J¼3.3, 4.4, 10.0 Hz), 2.84 (1H, dd,
J¼11.3, 12.4 Hz), 1.64e1.46 (4H, m), 1.42e1.28 (10H, m) ppm; 13C
NMR (67.5 MHz, CD3OD, rt): 78.5, 77.3, 74.6, 68.8, 63.0, 61.0, 58.7,
[M]þ found m/z 793.4580, C49H63NOþ8 requires m/z 793.4554.
4.2.17.3. (2R,3R,4R,5S)-4,5-Dibenzyloxy-1-benzyloxycarbonyl-2-
benzyloxymethyl-3-[12-(tetrahydropyran-2-yloxy)dodecyloxy] piper-
idine (22c). Oil, yield 25%; 1H NMR (270 MHz, CD3OD, rt): 7.35e7.23
(20H, m), 5.13 (1H, d, J¼12.4 Hz), 5.08 (1H, d, J¼12.4 Hz), 4.69 (1H, d,
J¼11.6 Hz), 4.64 (1H, d, J¼11.8 Hz), 4.63 (1H, d, J¼11.6 Hz), 4.57 (1H,
dd, J¼2.8, 4.1 Hz), 4.52 (1H, d, J¼12.0 Hz), 4.44 (1H, d, J¼11.8 Hz),
4.43 (1H, d, J¼12.0 Hz), 4.12e4.03 (2H, m), 3.87 (1H, ddd, J¼3.9, 7.0,
11.0 Hz), 3.78e3.60 (7H, m), 3.54e3.30 (4H, m), 1.88e1.43 (10H, m),
1.43e1.18 (16H, m) ppm; 13C NMR (67.5 MHz, CD3OD, rt): 155.7,
138.33, 138.28, 138.1, 136.6, 128.4, 128.3, 127.86, 127.83, 127.76,
127.65, 127.58, 127.54, 127.50, 98.8, 82.4, 78.7, 75.0, 73.1, 73.0, 71.8,
70.6, 68.6, 67.7, 67.2, 62.3, 56.1, 41.6, 30.8, 30.1, 29.8, 29.6, 29.5, 26.2,
47.4, 33.6, 31.3, 30.7, 30.5, 27.2, 26.9 ppm; ½a D27
þ19.7 (c 0.60,
ꢁ
MeOH); HR-FAB-MS (positive): [MþH]þ found m/z 306.2252,
C15H32NOþ5 requires m/z 306.2280.
4.2.19.3. (2R,3R,4R,5S)-4,5-Dihydroxy-2-hydroxymethyl-3-(12-
hydroxydodecyloxy)piperidine hydrochloride (23c). Crystal, yield
81%; 1H NMR (270 MHz, CD3OD, rt): 3.92 (1H, td, J¼6.5, 8.9 Hz), 3.85
(1H, dd, J¼3.3, 11.7 Hz), 3.80 (1H, dd, J¼4.3, 11.7 Hz), 3.65 (1H, ddd,
J¼5.0, 8.9,11.3 Hz), 3.60 (1H, td, J¼6.6, 8.9 Hz), 3.53 (2H, t, J¼6.5 Hz),
3.45 (1H, dd, J¼8.9, 8.9 Hz), 3.33 (1H, dd, J¼8.9, 10.2 Hz), 3.30 (1H,
dd, J¼5.0, 12.4 Hz), 3.08 (1H, ddd, J¼3.3, 4.3, 10.2 Hz), 2.84 (1H, dd,
J¼11.3, 12.4 Hz), 1.62e1.46 (4H, m), 1.42e1.28 (16H, m) ppm; 13C
NMR (67.5 MHz, CD3OD, rt): 78.5, 77.3, 74.6, 68.8, 63.0, 61.0, 58.7,
26.1, 25.5, 19.7 ppm; ½a D27
þ10.2 (c 1.00, CHCl3); HR-FD-MS (posi-
ꢁ
tive): [M]þ found m/z 835.5048, C52H69NOþ8 requires m/z 835.5023.
47.3, 33.7, 31.3, 30.7, 30.6, 27.2, 26.9 ppm; ½a D27
þ20.4 (c 0.39,
ꢁ
MeOH); HR-FAB-MS (positive): [MþH]þ found m/z 348.2726,
C18H38NOþ5 requires m/z 348.2750.
4.2.18. Synthesis of (2R,3R,4R,5S)-4,5-dibenzyloxy-1-
benzyloxycarbonyl-2-benzyloxymethyl-3-[15-(tetrahydropyran-2-
yloxy)pentadecyloxy] piperidine (22d). Compounds 21d (249.3 mg,
0.569 mmol) and 11 (136.1 mg, 0.24 mmol) were dissolved in THF/
DMF (3 mL, 1/1) and NaH (23.2 mg, 0.967 mmol) was added. After
stirring for 6 h, satd NH4Cl aq was added and extracted by EtOAc. The
organic layer was washed with brine, dried over sodium sulfate and
evaporated. The residue was purified by silica-gel column chroma-
tography (hexane/EtOAc¼4/1) to give 22d (80.9 mg, 38%) as an oil.
1H NMR (270 MHz, CD3OD, rt): 7.33e7.24 (20H, m), 5.13 (1H, d,
J¼12.4 Hz), 5.08 (1H, d, J¼12.4 Hz), 4.69 (1H, d, J¼11.5 Hz), 4.64 (1H,
d, J¼11.8 Hz), 4.63 (1H, d, J¼11.5 Hz), 4.57 (1H, dd, J¼3.0, 4.1 Hz),
4.52 (1H, d, J¼12.0 Hz), 4.44 (1H, d, J¼11.8 Hz), 4.43 (1H, d,
J¼12.0 Hz), 4.13e4.04 (2H, m), 3.87 (1H, ddd, J¼3.8, 7.1, 11.0 Hz),
3.78e3.62 (7H, m), 3.53e3.30 (4H, m), 1.88e1.43 (10H, m),
1.43e1.21 (22H, m) ppm 13C NMR (67.5 MHz, CD3OD, rt): 155.7,
138.3, 138.2, 138.0, 136.6, 128.3, 128.2, 127.78, 127.75, 127.68, 127.58,
127.51, 127.46, 127.44, 98.7, 82.3, 78.6, 74.9, 73.0, 72.9, 71.7, 70.5,
68.5, 67.6, 67.1, 62.2, 56.0, 41.5, 30.7, 30.0, 29.7, 29.6, 29.5, 29.4, 26.2,
4.2.19.4. (2R,3R,4R,5S)-4,5-Dihydroxy-2-hydroxymethyl-3-(15-
hydroxypentadecyloxy)piperidine hydrochloride (23d). Crystal, yield
48%; 1H NMR (270 MHz, CD3OD, rt): 3.92 (1H, td, J¼6.4, 8.9 Hz), 3.85
(1H, dd, J¼3.3, 11.7 Hz), 3.80 (1H, dd, J¼4.2, 11.7 Hz), 3.63 (1H, ddd,
J¼5.1, 8.9, 11.3 Hz), 3.59 (1H, td, J¼6.5, 9.0 Hz), 3.52 (2H, t, J¼6.5 Hz),
3.44 (1H, dd, J¼8.9, 8.9 Hz), 3.32 (1H, dd, J¼8.9, 10.2 Hz), 3.30 (1H,
dd, J¼5.1, 12.2 Hz), 3.07 (1H, ddd, J¼3.3, 4.4, 10.2 Hz), 2.83 (1H, dd,
J¼11.3, 12.2 Hz), 1.63e1.46 (4H, m), 1.40e1.27 (22H, m) ppm, 13C
NMR (67.5 MHz, CD3OD, rt): 78.5, 77.3, 74.6, 68.8, 63.0, 61.0, 58.7,
47.3, 33.6, 31.3, 30.8, 30.8, 30.7, 30.61, 30.59, 27.2, 26.9 ppm; ½a D27
ꢁ
þ22.6 (c 0.67, MeOH); HR-FAB-MS (positive): [MþH]þ found m/z
390.3199, C21H44NO5þ requires m/z 390.3219.
4.2.20. Synthesis of 23e,f. Protective groups of 19e and 19f were
removed by the method written in Section 4.2.8 to give 23e,f.
4.2.20.1. (2R,3R,4R,5S)-4,5-Dihydroxy-2-hydroxymethyl-3-(4-
hydroxybutyloxy)piperidine hydrochloride (23e). Crystal, yield 93%;
1H NMR (270 MHz, CD3OD, rt): 3.98e3.91 (1H, m), 3.83 (2H, d,
J¼3.9 Hz), 3.69e3.60 (2H, m), 3.57 (1H, t, J¼6.1 Hz), 3.46 (1H, dd,
J¼8.9, 8.9 Hz), 3.34 (1H, dd, J¼8.9, 10.2 Hz), 3.30 (1H, dd, J¼4.9,
12.2 Hz), 3.08 (1H, dt, J¼10.2, 3.9 Hz), 2.84 (1H, dd, J¼11.4, 12.2 Hz)
ppm; 13C NMR (67.5 MHz, CD3OD, rt): 78.5, 77.3, 74.3, 68.8, 62.7,
26.0, 25.4, 19.6 ppm; ½a D27
þ7.7 (c 1.00, CHCl3); HR-FD-MS (posi-
ꢁ
tive): [M]þ found m/z 877.5487, C55H75NOþ8 requires m/z 877.5493.
4.2.19. General procedure for the synthesis of 23a-d. Compound 22
(1 equiv) was dissolved in MeOH/THF (4/1), PPTS (0.5 equiv) was
added and stirred for 15 h at 50 ꢀC. The reaction mixture was
acidified by 1 M HCl aq to pH 2, Pd(OH)2 was added and stirred for
20 h under hydrogen atmosphere. The mixture was passed through
Celite pad, evaporated and purified by LiChrolutÒ RP-18 (Merck Co.)
to give 23.
61.0, 58.7, 47.3, 30.2, 27.7 ppm; ½a D27
þ28.1 (c 0.25, MeOH); HR-FAB-
ꢁ
MS (positive): [MþH]þ found m/z 236.1515, C10H22NOþ5 requires
m/z 236.1498.
4.2.20.2. (2R,3R,4R,5S)-4,5-Dihydroxy-2-hydroxymethyl-3-(5-
hydroxypentyloxy)piperidine hydrochloride (23f). Crystal, yield 93%;
1H NMR (270 MHz, CD3OD, rt): 3.93 (1H, td, J¼6.4, 9.0 Hz), 3.87 (1H,
dd, J¼3.0,12.0 Hz), 3.82 (1H, dd, J¼4.2,12.0 Hz), 3.66 (1H, ddd, J¼5.1,
8.9, 11.1 Hz), 3.65e3.58 (1H, m), 3.55 (2H, t, J¼6.3 Hz), 3.46 (1H, dd,
J¼8.9, 8.9 Hz), 3.34 (1H, dd, J¼8.9, 10.1 Hz), 3.30 (1H, dd, J¼5.1,
12.4 Hz), 3.09 (1H, ddd, J¼3.0, 4.2, 10.1 Hz), 2.84 (1H, dd, J¼11.1,
12.4 Hz), 1.67e1.39 (6H, m) ppm; 13C NMR (67.5 MHz, CD3OD, rt):
4.2.19.1. (2R,3R,4R,5S)-4,5-Dihydroxy-2-hydroxymethyl-3-(6-
hydroxyhexyloxy)piperidine hydrochloride (23a). Crystal, yield 85%;
1H NMR (270 MHz, CD3OD, rt): 3.92 (1H, td, J¼6.3, 9.0 Hz), 3.86 (1H,
dd, J¼3.3, 11.7 Hz), 3.80 (1H, dd, J¼4.4, 11.7 Hz), 3.65 (1H, ddd, J¼5.1,
9.0,11.2Hz), 3.61(1H, td, J¼6.9,9.0Hz), 3.54(2H, t, J¼6.5Hz), 3.45(1H,
dd, J¼9.0, 9.0 Hz), 3.33 (1H, dd, J¼9.0, 10.0 Hz), 3.31 (1H, dd, J¼5.1,
12.4 Hz), 3.08 (1H, ddd, J¼3.3, 4.4, 10.0 Hz), 2.84 (1H, dd, J¼11.2,
12.4 Hz), 1.65e1.48 (4H, m), 1.44e1.34 (4H, m) ppm; 13C NMR
(67.5 MHz, CD3OD, rt): 78.4, 77.3, 74.4, 68.8, 62.9, 61.0, 58.7, 47.4, 33.5,
78.4, 77.3, 74.4, 68.8, 62.8, 61.0, 58.7, 47.3, 33.4, 31.0, 23.5 ppm; ½a D27
ꢁ
þ26.0 (c 0.58, MeOH); HR-FD-MS (positive): [M]þ found m/z
249.1594, C11H23NO5þ requires m/z 249.1576.
31.2, 27.0, 26.7 ppm; ½a D27
þ25.3 (c 1.20, MeOH); HR-FAB-MS (posi-
ꢁ
tive): [MþH]þ found m/z 264.1829, C12H26NO5þ requires m/z 264.1811.
4.3.
a-Amylase inhibition assay
4.2.19.2. (2R,3R,4R,5S)-4,5-Dihydroxy-2-hydroxymethyl-3-(9-
hydroxynonyloxy)piperidine hydrochloride (23b). Crystal, yield 75%;
1H NMR (270 MHz, CD3OD, rt): 3.92 (1H, td, J¼6.3, 8.9 Hz), 3.86 (1H,
dd, J¼3.3, 11.7 Hz), 3.81 (1H, dd, J¼4.4, 11.7 Hz), 3.66 (1H, ddd, J¼5.1,
8.9, 11.3 Hz), 3.60 (1H, td, J¼6.6, 9.0 Hz), 3.53 (2H, t, J¼6.5 Hz), 3.45
(1H, dd, J¼8.9, 8.9 Hz), 3.33 (1H, dd, J¼8.9, 10.0 Hz), 3.30 (1H, dd,
Samples (dissolved in 20% DMSO (aq)) (10
atic -amylase (1 unit/mL, 10 L), and buffer solution (100 mM
sodium phosphate, 50 mM sodium chloride, pH 6.9, 30 L) were
mixed and pre-incubated at 37 ꢀC for 5 min. To this mixture, 2,4-
dinitrophenyl maltotriose (2 mM, 50 L) dissolved in the buffer
mL), porcine pancre-
a
m
m
m

7702
E. Kato et al. / Tetrahedron 67 (2011) 7692e7702
3. Yoshikawa, M.; Murakami, T.; Shimada, H.; Matsuda, H.; Yamahara, J.; Tanabe,
G.; Muraoka, O. Tetrahedron Lett. 1997, 38, 8367e8370.
4. (a) Scott, L. J.; Spencer, C. M. Drugs 2000, 59, 521e549; (b) Chen, X.; Zheng, Y.;
solution was added to start the enzyme reaction. Absorbance at
405 nm was monitored temporally to determine the rate of enzyme
reaction. Inhibition rate was determined by comparing the rate of
hydrolysis between the control reaction (without sample) and
sample reaction. Each experiment was repeated at least three times
to determine IC50 values or % inhibition.
Shen, Y. Curr. Med. Chem. 2006, 13, 109e116.
ꢀ
ꢀ
ꢀ ꢀ
5. (a) Zajacz, A; Gyemant, G.; Vittori, N.; Kandra, L. Carbohydr. Res. 2007, 342,
717e723; (b) Ali, H.; Houghton, P. J.; Soumyanath, A. J. Ethnopharmacol. 2006,
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Acknowledgements
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6284e6294.
This research was supported by the Grant-in-Aid for Scientific
Research (KAKENHI 21603001). We would like to give our appre-
ciation to Mr. Kenji Watanabe, Dr. Eri Fukushi and Mr. Yusuke
Takata of the GCeMS and NMR Laboratory, Graduate School of
Agriculture, Hokkaido University for measuring mass spectra.
9. Brayer, G. D.; Sidhu, G.; Maurus, R.; Rydberg, E. H.; Braun, C.; Wang, Y.; Nguyen,
N. T.; Overall, C. M.; Withers, S. G. Biochemistry 2000, 39, 4778e4791.
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References and notes
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16. RCSB Protein data bank, http://www.rcsb.org/pdb/home/home.do, PDB ID:
1OSE.
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