New 1-amino-1-deoxy- and 2-amino-2-deoxy-polyhydroxyazepanes: Synthesis and inhibition of glycosidases

Article abstract of DOI:10.1016/j.tetasy.2004.12.005

Eight new seven-membered ring iminoalditols, displaying an amino group and a hydroxymethyl group on the ring, have been synthesized from d-arabinose via epoxidation of a protected azacycloheptene and subsequent nucleophilic opening. Three of them show a p

Full text of DOI:10.1016/j.tetasy.2004.12.005

Tetrahedron:
Asymmetry
Tetrahedron: Asymmetry 16 (2005) 313–319
New 1-amino-1-deoxy- and 2-amino-2-deoxy-
polyhydroxyazepanes: synthesis and inhibition of glycosidases
a
Hongqing Li, Yves Bleriot, Jean-Maurice Mallet, Eliazar Rodriguez-Garcia,
a,
a
b
*
´
Pierre Vogel,b Yongmin Zhanga and Pierre Sinaya
¨
a
´
´
Ecole Normale Superieure, Departement de Chimie, UMR 8642, 24 rue Lhomond, 75231 Paris Cedex 05, France
b
´
´
Laboratoire de glycochimie et de synthese asymetrique, Swiss Federal Institute of Technology (EPFL) BCH,
CH-1015 Lausanne-Dorigny, Switzerland
Received 22 November 2004; accepted 2 December 2004
Available online 13 January 2005
Abstract—Eight new seven-membered ring iminoalditols, displaying an amino group and a hydroxymethyl group on the ring, have
been synthesized from D-arabinose via epoxidation of a protected azacycloheptene and subsequent nucleophilic opening. Three of
them show a potent glycosidase inhibition on amyloglucosidase and, to a lesser extend, on a-L-fucosidase.
Ó 2004 Elsevier Ltd. All rights reserved.
H
N
H
N
H
N
1. Introduction
HO
HO
HO
HO
HO
HO
HO
HO
HO
OH
OH
OH
OH
OH
OH
The quest for potent and selective glycosidase inhibitors
has emerged from their therapeutic potential;1 several
glycosidase inhibitors are being currently tested or ap-
proved in the treatment of diabetes,2 GaucherÕs disease,3
HIVinfection, 4 viral infection5 or cancer.6 Some of them
have also been used as chemical probes, in combination
with protein crystallography and kinetics studies, to
provide new insights into glycosidase mechanism.7
Extensive synthetic work has led to the design of many
five- and six-membered ring azasugars,8 which mimic
the ring size of their parent sugar, but only a few higher
homologues with seven-9 or eight-membered rings10
have been synthesized so far. As part of an ongoing pro-
ject on the design of new carbohydrates mimetics, we
have already reported the synthesis, conformational
study and the biological evaluation of D-gluco-, D-man-
no-11,12 and D-galacto-like13 1,6-dideoxy-1,6-iminohepti-
tols (Fig. 1), some of which display potent glycosidase
inhibition.
α-D-gluco-
α-D-galacto-
β-D-manno-
analogue
analogue
analogue
Figure 1. Structure of 1,6-dideoxy-1,6-iminoheptitols previously
reported.
logues of nojirimycin. Insertion of a methylene group
between the nitrogen atom and the pseudoanomeric hy-
droxyl group ensures chemical stability unlike nojirimy-
cin. We anticipated that the relative flexibility of such
structures associated with the unusual spatial distribu-
tion of the hydroxyl groups might generate an atypical
inhibition profile for these molecules. This was indeed
the case with the a-D-gluco analogue, which was found
to be a rather potent and selective green coffee bean
a-galactosidase inhibitor (Ki 2.2 lM),1 the a-D-galacto
analogue being almost inactive.13 Other compounds
were also recently reported by Dhivale et al.14 All these
compounds were obtained through the syn-dihydroxyl-
ation of the C@C bond of a fully protected azacyclohep-
tene. We have now explored the epoxidation of this
C@C bond and its subsequent opening with sodium
azide to access 1,2-trans-hydroxylamino derivatives.
This 1,2-trans-hydroxylamino motif displayed on an
azepane ring is found in balanol, a fungal metabolite
These seven-membered ring compounds possess an extra
hydroxymethyl group in order to closely mimic the par-
ent sugar and can also be considered as higher homo-
*
Corresponding author. Tel.: +33 1 44 32 38 67; fax: +33 1 44 32 33
97; e-mail: yves.bleriot@ens.fr
0957-4166/$ - see front matter Ó 2004 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tetasy.2004.12.005

314
H. Li et al. / Tetrahedron: Asymmetry 16 (2005) 313–319
produced by Verticillium balanoides with potent protein
kinase C inhibitory properties.15 Constrained diamine
systems continue to attract synthetic interest due to their
potential as therapeutic agents while 3-aminoazepane
derivatives have been developed as antitumour chiral
cis-platin analogues.16 Polyhydroxylated azepanes with
an extra amino group on the ring have been reported
before by Farr et al.17 and Wang et al.18 but unfortu-
nately FarrÕs compound was not active on jack bean
mannosidase while no inhibition data were reported
for WangÕs molecule. Another compound of this type
has been described by Depezay et al. who used the aze-
pane ring as a scaffold to design non-peptide mimics
of somatostatin.19 Herein, we report the synthesis and
biological evaluation of a series of new 1,6-dideoxy-
1,6-iminoheptitols displaying an amino group at the
pseudoanomeric or at the pseudo C-2 position of the
ring (Fig. 2). For clarity reasons, the numbering used
for these compounds follows the numbering of the
parent pyranoside to emphasize the analogy between
the azepanes and the corresponding monosaccharides.
2. Results and discussion
Our strategy takes advantage of our previously reported
azacycloheptenes 9 and 10 and is based on the ring open-
ing of the corresponding epoxides with sodium azide
followed by subsequent hydrogenation. Treatment of
compound 9 with m-CPBA in dichloromethane afforded
the separable epoxides 11 (29% yield) and 12 (53% yield)
in a 5/3 ratio in favour of compound 12. Subsequent ring
opening of epoxides 11 and 12 with sodium azide in the
presence of ammonium chloride20 gave in high yield the
1-azido-1-deoxy and 2-azido-2-deoxy derivatives 13
(34% yield), 14 (55% yield) and 15 (28% yield), 16
(57% yield). Final hydrogenolysis converted the azido
group into an amino group and quantitatively afforded
the corresponding 1-amino-1-deoxy- and 2-amino-2-
deoxy-polyhydroxylated azepanes 1–4 (Scheme 1).
The same sequence was uneventfully applied to the dia-
stereomeric azacycloheptene 10 to afford the correspond-
ing azepanes 5–8. Treatment of compound 10 with
H
N
H
N
H
N
H
N
6
6
HO
HO
HO
HO
HO
HO
5
7
5
7
4
4
1
1
HO
HO
Wang's compound
NH2
HO
HO
Farr's compound
OH
NH2
OH
New structures 1-8
OH
NH2
3
2
3
2
OH
NH2
Figure 2. Analogy between Farr et al. and Wang co-workers compounds and the amino-1,6-dideoxy-1,6-iminoheptitols 1–8 described herein.
Z
N
BnO
BnO
BnO
9
i
Z
Z
N
N
BnO
BnO
BnO
BnO
BnO
BnO
3 : 5
O
O
11
12
ii
ii
Z
Z
Z
Z
N
BnO
N
N
N
BnO
BnO
BnO
+
+
BnO
BnO
OH
BnO
BnO
N3 BnO
BnO
N3
BnO
BnO
OH
N3
OH
OH
N3
15
16
13
14
iii
iii
iii
iii
H
N
H
N
H
N
H
N
HO
HO
HO
HO
HO
HO
HO
OH
NH2
NH2
HO
NH2
OH
NH2
HO
HO
OH
HO
OH
HO
1
2
3
4
Scheme 1. Synthesis of aminopolyhydroxyazepanes 1–4. Reagents and conditions: (i) m-CPBA, CH2Cl2, 82% yield; (ii) NaN3, NH4Cl, DMF/H2O,
90 °C, 85–89% yield; (iii) H2, 10% Pd/C AcOH quant.

H. Li et al. / Tetrahedron: Asymmetry 16 (2005) 313–319
315
m-CPBA in dichloromethane afforded the separable
epoxides 17 (42% yield) and 18 (42% yield). Subsequent
ring opening of epoxides 17 and 18 with sodium azide
in the presence of ammonium chloride gave the 1-azi-
do-1-deoxy- and 2-azido-2-deoxy-derivatives 19 (64%
yield), 20 (29% yield) and 21 (23% yield), 22 (69% yield)
in very high yield. Final hydrogenolysis afforded quanti-
tatively the corresponding 1-amino-1-deoxy- and 2-ami-
no-2-deoxy-polyhydroxylated azepanes 5–8 (Scheme 2).
The NMR analysis of all the Z-protected compounds
was found problematic due to the presence of rotamers
generated from the p-bonding between the nitrogen and
carbonyl group of the benzyloxycarbonyl group. The
stereochemistry at positions 1 and 2 of compounds 1–8
was thus obtained from the analysis of their respective
NMR spectra (Fig. 3) while the structure of compound
7
was deduced from the structures of other
compounds.21
Z
N
BnO
BnO
BnO
9
i
Z
Z
N
N
BnO
BnO
BnO
BnO
BnO
BnO
O
O
17
18
ii
ii
Z
Z
Z
Z
N
BnO
N
N
N
BnO
BnO
BnO
+
+
BnO
BnO
OH
BnO
BnO
N3 BnO
BnO
N3
BnO
BnO
OH
N3
OH
OH
N3
21
22
19
20
iii
iii
iii
iii
H
N
H
N
H
N
H
N
HO
HO
HO
HO
HO
HO
HO
OH
NH2
NH2
HO
NH2
OH
NH2
HO
HO
OH
HO
OH
HO
5
6
7
8
Scheme 2. Synthesis of aminopolyhydroxyazepanes 5–8. Reagents and conditions: (i) m-CPBA, CH2Cl2, 84% yield; (ii) NaN3, NH4Cl, DMF/H2O,
90 °C, 92% yield; (iii) H2, 10% Pd/C AcOH quant.
H
N
H
N
H
N
H
N
6
HO
HO
HO
HO
HO
HO
HO
HO
HO
HO
HO
HO
7
5
1
1
1
4
1
OH
NH2
OH
NH2
NH2
OH
NH2
OH
2
2
2
3
3
2
3
3
1
2
3
4
J1,2 = 9.1 Hz
J2,3 = 9.1 Hz
J1,2 = 10.2 Hz
J
J
J
1,2 = 10.0 Hz
2,3 = 1.5 Hz
3,4 = 6.6 Hz
J2,3 = 8.5 Hz
J3,4 = 8.5 Hz
J
J
2,3 = 1.4 Hz
3,4 = 6.3 Hz
H
N
H
N
H
N
H
N
HO
HO
HO
HO
HO
HO
HO
HO
HO
HO
HO
HO
1
1
1
1
OH
OH
NH2
NH2
2
2
2
2
3
3
3
3
NH2
NH2
OH
OH
5
6
7
8
not determined
J1,2 = 10.2 Hz
J2,3 = 5.0 Hz
J1,2 = 10.3 Hz
J1,2 = 9.9 Hz
J2,3 = 2.9 Hz
J3,4 = 8.0 Hz
J
J
2,3 = 2.6 Hz
3,4 = 5.8 Hz
Figure 3. Important 3J coupling constants for compounds 1–8.

316
H. Li et al. / Tetrahedron: Asymmetry 16 (2005) 313–319
O
O
O
O
O
O
O
O
O
O
O
O
Z
N
N
N
N
TBDMSO
N
i
ii
iii
+
O
O
O
O
O
O
O
O
23
24
25
26
27
Scheme 3. Access to epoxides 26 and 27. Reagents and conditions: (i) TBAF, THF, 99% yield; (ii) GrubbsÕ catalyst, CH2Cl2, 96%; m-CPBA, CH2Cl2,
75%.
fore the readily available diene 23 was first quantita-
tively converted to the bicyclic oxazolidinone 24 by
treatment with TBAF in THF. This conformationally
locked oxazolidinone was subjected to RCM using
GrubbÕs catalyst to afford the corresponding tricyclic
azacycloheptene 25 in excellent yield (96%). Treatment
of 25 with m-CPBA in dichloromethane afforded epox-
ide 26 (53% yield) trans to the oxazolidinone ring along
with diastereomeric epoxide 27 (22% yield) (Scheme 3).
The structure of epoxide 26 was confirmed by X-ray
analysis (Fig. 4).22 Work is currently in progress to ex-
plore the regioselective opening of epoxides 26 and 27
with several nucleophiles.
2.1. Inhibition on glycosidases
The eight iminoheptitols have been assayed for their
inhibitory activity towards 24 commercially available
glycosidases.23 They did not inhibit the following en-
zymes at 1 mM: a-galactosidase from E. coli, b-galacto-
sidases from E. coli, Aspergillus niger and Aspergillus
oryzae, a-glucosidases from rice, b-glucosidases from
Figure 4. X-ray structure of epoxide 26.
almonds and Saccharomyces cerevisiae b-mannosidase
from Helix pomatia, b-xylosidase from A. niger, a-N-
acetylglucosaminidase from chicken liver, b-N-acetyl-
glucosaminidases from jack bean and bovine epididymis
A and B. For other enzymes the results are shown in
Tables 1 and 2.
We were also interested in applying our sequence to
orthogonally protected azacycloheptenes in order to en-
able a future regioselective modification of virtually each
hydroxyl group present on the ring. This access to such
azacycloheptenes has already been described.13 There-
Table 1. Inhibitory activity of compounds 1, 2, 3 and 4
Compound/enzyme
H
H
N
H
N
H
N
HO
HO
HO
N
HO
HO
HO
HO
HO
HO
HO
HO
HO
OH
NH2
NH2
OH
NH2
OH
OH
NH2
1
2
3
4
a-L-Fucosidase
Bovine epididymis
42%
NI
82% (100 lM)
30%
76%
40%
22%
34%
25%
NI
a-Galactosidase
Coffee beans
b-Galactosidase
Bovine liver
76%
35%
39%
62%
21%
a-Glucosidase
Yeast
30%
Amyloglucosidase
Aspergillus niger
Rhizopus mould
95% (105 lM)
92% (143 lM)
82%
83%
85% (152 lM)
85% (245 lM)
56%
57%
a-Mannosidase
Jack bean
Almonds
NI
NI
33%
24%
30%
24%
NI
NI
Percentage of inhibition at 1 mM concentration, IC50 (in brackets), optimal pH, 35 °C, NI = no inhibition at 1 mM concentration of the inhibitor.

H. Li et al. / Tetrahedron: Asymmetry 16 (2005) 313–319
Table 2. Inhibitory activity of compounds 5, 6, 7 and 8
317
Compound/enzyme
H
N
H
N
H
N
H
N
HO
HO
HO
HO
HO
HO
HO
HO
HO
HO
HO
HO
OH
NH2
NH2
OH
NH2
OH
OH
NH2
5
6
7
8
a-L-Fucosidase
Bovine epididymis
57%
NI
67%
NI
48%
49%
39%
NI
a-Galactosidase
Coffee beans
NI
b-Galactosidase
Bovine liver
31%
28%
23%
Percentage of inhibition at 1 mM concentration, IC50 (in brackets), optimal pH, 35 °C, NI = no inhibition at 1 mM concentration of the inhibitor.
Compounds 1–8 display a profile of inhibition very dif-
ferent from the ones obtained with our previously re-
ported polyhydroxylated azepanes.11 In fact none of
them significantly inhibit a-galactosidase from coffee
beans or b-galactosidase from bovine liver, the two en-
zymes, which were strongly inactivated before. Intro-
duction of an amino group on the ring combined with
a trans relationship of the OH and NH2 groups located
at positions 1 and 2 of the azepanes greatly modifies the
inhibition profile of these molecules. Furthermore none
of the enzymes inhibited with this new series of com-
pounds were significantly inactivated with the previously
reported compounds. We saw that compounds 1–4 with
an (R)-configured hydroxymethyl group were better
inhibitors than compounds 5–8, which displayed an
(S)-configured CH2OH group, a trend already observed
with previously reported polyhydroxylated azepanes.
Compounds 1 and 3 show the best results and display
a rather good and selective inhibition of mixed type on
amyloglucosidase from A. niger and Rhizopus mould.
These enzymes hydrolyze both 1,4- and 1,6-a-glucosidic
linkages24 and thus constitute very important industrial
enzymes used to convert starch to glucose.25 Interest-
ingly, compound 1, a 2-amino-2-deoxy-b-D-gluco ana-
logue and compound 3, a 1-amino-1-deoxy-b-D-gluco
analogue, both inhibit an a-glucosidase despite a
b-pseudoanomeric substituent. These results can be ex-
plained by an unusual conformation imposed by the
seven-membered ring, an explanation already invoked
and proven valid in the case of an a-D-gluco analogue
displaying good inhibition on a-galactosidase from
coffee beans.13 To our knowledge, these are the first
examples of polyhydroxylated azepanes inhibiting
amylogluco-sidase. Compound 2, a 1-amino-1-deoxy-
a-D-manno analogue, whilst displaying a poor inhibition
on a-mannosidase, is a moderate inhibitor of a-L-fucosi-
dase from bovine epididymis (IC50 100 lM) being less
potent than other reported polyhydroxylated aze-
panes.9f,l,26 Work is currently in progress to rationalize
these biological results.
our previously reported azacycloheptenes 9 and 10.
Compounds 1 and 3, displaying, respectively, a 2-amino-
2-deoxy-b-D-gluco and a 1-amino-1-deoxy-b-D-gluco
configuration, inhibit amyloglucosidase, while com-
pound 2 with a 1-amino-1-deoxy-a-D-manno configura-
tion inhibits an a-L-fucosidase in the micromolar
range. The introduction of an amino group either at
the pseudoanomeric position or at the C-2 position of
the ring combined with the trans relationship between
the substituents at positions C-1 and C-2 generates a
completely new inhibition profile for these compounds.
Work is currently in progress to synthesize the 1,2-
trans-diols and the N-acetyl derivatives at positions 1
and 2, which should hopefully inhibit other enzymes,
such as hexosaminidases, as reported by Wong et al.
for other polyhydroxylated azepanes.26
Acknowledgements
´
We thank Patrick Herson from the Centre de Resolution
des Structures (Universite Pierre et Marie Curie, Paris)
´
for solving the X-ray structure of compound 26.
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iminoheptitols 1–8 displaying an amino group and an
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318
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H-7a), 3.47 (dd, 1H, J = 6.4 Hz, J = 14.6 Hz, H-7b), 3.37
(t, 1H, J = 9.1 Hz, H-2), 3.36 (ddd, 1H, J = 3.5 Hz,
J = 6.7 Hz, J = 8.9 Hz, H-5); 13C NMR (D2O,
100 MHz): 70.17 (C-3), 69.74 (C-4), 64.70 (C-1), 61.20
(C-5), 59.22 (C-6), 57.83 (C-2), 48.39 (C-7); m/z (CI, NH3):
193 (M+H+, 100%); HRMS (CI, NH3): calcd for
C7H17O4N2 (M+H+): 193.1188, found 193.1192.
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Compound 2: [a]D = +27 (c 0.58, CH3OH); 1H NMR
(D2O, 400 MHz): 4.33 (dd, 1H, J = 1.4 Hz, J = 6.3 Hz, H-
3), 4.28 (dd, 1H, J = 1.4 Hz, J = 10.2 Hz, H-2), 4.10 (dd,
1H, J = 3.3 Hz, J = 6.3 Hz, H-4), 3.95 (dd, 1H, J = 4.3 Hz,
J = 12.2 Hz, H-6a), 3.90 (ddd, 1H, J = 4.1 Hz, J =
10.2 Hz, J = 12.0 Hz, H-1), 3.81 (dd, 1H, J = 9.0 Hz,
J = 12.2 Hz, H-6b), 3.78 (dd, 1H, J = 4.1 Hz, J =
13.7 Hz, H-7a), 3.46 (ddd, 1H, J = 3.3 Hz, J = 4.3 Hz,
J = 9.0 Hz, H-5), 3.37 (dd, 1H, J = 12.0 Hz, J = 13.7 Hz,
H-7b); 13C NMR (D2O, 100 MHz): 74.59 (C-3), 68.68 (C-
2), 67.17 (C-5), 67.04 (C-4), 61.28 (C-6), 49.62 (C-1), 44.13
(C-7); m/z (CI, NH3): 193 (M+H+, 100%); HRMS (CI, NH3):
calcd for C7H17O4N2 (M+H+): 193.1188, found 193.1185.
Compound 3: [a]D = ꢀ1 (c 0.3, CH3OH); 1H NMR (D2O,
400 MHz): 4.00 (dd, 1H, J = 3.7 Hz, J = 12.5 Hz, H-6a),
3.94 (dd, 1H, J = 6.5 Hz,J = 12.5 Hz, H-6b), 3.85 (t, 1H,
J = 8.5 Hz, H-4), 3.78 (m, 2H, H-1, H-2), 3.69 (m, 2H, H-
3, H-7a), 3.51 (ddd, 1H, J = 3.7 Hz, J = 6.5 Hz,
J = 8.5 Hz, H-5), 3.49 (dd, 1H, J = 9.3 Hz, J = 14.3 Hz,
H-7b); 13C NMR (D2O, 100 MHz): 76.20 (C-3), 72.23 (C-
2), 68.06 (C-4), 59.70 (C-5), 58.72 (C-6), 49.06 (C-1), 42.31
(C-7); m/z (CI, NH3): 193 (M+H+, 100%); HRMS (CI,
NH3): calcd for C7H17O4N2 (M+H+): 193.1188, found
193.1193.
10. Godin, G.; Garnier, E.; Compain, P.; Martin, O. R.;
Ikeda, K.; Asano, N. Tetrahedron Lett. 2004, 45, 579–581.
´
11. Li, H.; Bleriot, Y.; Chantereau, C.; Mallet, J.-M.; Sollo-
goub, M.; Zhang, Y.; Rodriguez-Garcia, E.; Vogel, P.;
Compound 4: [a]D = +32 (c 0.54, CH3OH); 1H NMR
(D2O, 400 MHz): 4.41 (dd, 1H, J = 1.5 Hz, J = 6.6 Hz, H-
3), 4.32 (ddd, 1H, J = 4.3 Hz, J = 10.8 Hz, J = 14.6 Hz, H-
1), 4.15 (dd, 1H, J = 2.7 Hz, J = 6.7 Hz, H-4), 3.93 (dd,
1H, J = 4.6 Hz, J = 12.2 Hz, H-6a), 3.79 (dd, 1H,
J = 9.2 Hz, J = 12.2 Hz, H-6b), 3.80 (dd, 1H, J = 1.5 Hz,
J = 10.0 Hz, H-2), 3.63 (dd, 1H, J = 4.3 Hz, J = 13.6 Hz,
H-7a), 3.50 (ddd, 1H, J = 2.7 Hz, J = 4.6 Hz, J = 9.2 Hz,
H-5), 3.28 (dd, 1H, J = 11.1 Hz, J = 13.6 Hz, H-7b); 13C
NMR (D2O, 100 MHz): 69.52 (C-3), 67.26 (C-4), 66.28 (C-
5), 64.87 (C-1), 61.36 (C-6), 55.12 (C-2), 47.93 (C-7); m/z
(CI, NH3): 193 (M+H+, 100%); HRMS (CI, NH3): calcd
for C7H17O4N2 (M+H+): 193.1188, found 193.1189.
Compound 5: [a]D = ꢀ9 (c 0.42, CH3OH); 1H NMR
(D2O, 400 MHz): 4.42 (dt, 1H, J = 2.6 Hz, J = 10.1 Hz, H-
1), 4.11 (m, 2H, H-3, H-4), 3.84 (dd, 1H, J = 5.1 Hz,
J = 11.8 Hz, H-6a), 3.76 (dd, 1H, J = 8.8 Hz, J = 11.8 Hz,
H-6b), 3.66 (app. dd, 1H, J = 5.1 Hz, J = 8.8 Hz, H-5),
3.52 (dd, 1H, J = 2.5 Hz, J = 13.5 Hz, H-7a), 3.42 (dd, 1H,
J = 5.0 Hz, J = 10.1 Hz, H-2), 3.31 (dd, 1H, J = 10.4 Hz,
J = 13.5 Hz, H-7b); 13C NMR (D2O,100 MHz): 71.28 (C-
3), 69.00 (C-4), 64.34 (C-1), 61.13 (C-2), 60.62 (C-6), 57.64
(C-5), 49.60 (C-7); m/z (CI, NH3): 193 (M+H+, 100%);
HRMS (CI, NH3): calcd for C7H17O4N2 (M+H+):
193.1188, found 193.1190.
Jimenez-Barbero, J.; Sinay, P. Org. Biomol. Chem. 2004, 2,
1492–1499.
12. Martinet-Mayorga, K.; Medina-Franco, J. L.; Mari, S.;
Canada, F. J.; Rodriguez-Garcia, E.; Vogel, P.; Li, H.;
¨
´
Bleriot, Y.; Sinay, P.; Jimenez-Barbero, J. Eur. J. Org.
Chem. 2004, 20, 4119–4129.
´
¨
´
13. Li, H.; Bleriot, Y.; Mallet, J.-M.; Zhang, Y.; Rodriguez-
Garcia, E.; Vogel, P.; Mari, S.; Jimenez-Barbero, J.; Sinay,
¨
P. Heterocycles 2004, 64, 65–74.
14. Dhivale, D. D.; Markad, S. D.; Karanjule, N. S.;
Prakasha Reddy, J. J. Org. Chem. 2004, 69, 4760–4766.
15. Kulanthaivel, P.; Hallock, Y. F.; Boros, C.; Hamilton, S.
M.; Janzen, W. P.; Ballas, L. M.; Loomis, C. R.; Jiang, J.
B.; Katz, B.; Steiner, J. R.; Clardy, J. J. Am. Chem. Soc.
1993, 115, 6452–6453.
16. Rezler, E. M.; Fenton, R. R.; Esdale, W. J.; McKeage, M.
J.; Russell, P. J.; Hambley, T. W. J. Med. Chem. 1997, 40,
3508–3515.
17. Farr, R. A.; Holland, A. K.; Huber, E. W.; Peet, N. P.;
Weintraub, P. M. Tetrahedron 1994, 50, 1033–1044.
18. Andreana, P. R.; Sanders, T.; Janczuk, A.; Warrick, J. I.;
Wang, P. G. Tetrahedron Lett. 2002, 43, 6525–6528.
19. Damour, D.; Barreau, M.; Blanchard, J.-C.; Burgevin,
M.-C.; Doble, A.; Herman, F.; Pantel, G.; James-Surcouf,
E.; Vuilhorgne, M.; Mignani, S.; Poitout, L.; Le Merrer,
Y.; Depezay, J.-C. Bioorg. Med. Chem. Lett. 1996, 6,
1667–1672.
20. Bouzard, D.; Di Cesare, P.; Essiz, M.; Jacquet, J. P.;
Kiechel, J. R.; Remuzon, P.; Weber, A.; Oki, T.;
Masuyoshi, M.; Kessler, R. E.; Fung-Tomc, J.; Desiderio,
J. J. Med. Chem. 1990, 33, 1344–1352.
1
Compound 6: [a]D = +12 (c 1, CH3OH); H NMR (D2O,
400 MHz): 4.21 (dd, 1H, J = 2.6 Hz, J = 5.9 Hz, H-3), 4.13
(dd, 1H, J = 2.6 Hz, J = 10.3 Hz, H-2), 4.09 (d, 1H,
J = 5.9 Hz, H-4), 3.88 (dt, 1H, J = 4.0 Hz, J = 10.3 Hz,
H-1), 3.84 (m, 2H, H-6a, H-6b), 3.76 (m, 1H, H-5), 3.65
(dd, 1H, J = 3.8 Hz, J = 13.8 Hz, H-7a), 3.54 (dd, 1H,
J = 9.7 Hz, J = 13.8 Hz, H-7b); 13C NMR (D2O,
100 MHz): 71.35 (C-3), 69.26 (C-2), 66.97 (C-4), 60.55
(C-6), 55.95 (C-5), 46.83 (C-1), 43.35 (C-7); m/z (CI, NH3):
193 (M+H+, 100%); HRMS (CI, NH3): calcd for
C7H17O4N2 (M+H+): 193.1188, found 193.1189.
21. Selective data for compounds 1–8 and 26:
Compound 1: [a]D = +5 (c 0.24, CH3OH); 1H NMR (D2O,
400 MHz): 4.26 (ddd, 1H, J = 4.0 Hz, J = 6.4 Hz,
J = 9.1 Hz, H-1), 4.04 (dd, 1H, J = 3.5 Hz, J = 12.5 Hz,
H-6a), 3.90 (dd, 1H, J = 6.7 Hz, J = 12.5 Hz, H-6b), 3.80
(m, 2H, H-3, H-4), 3.52 (dd, 1H, J = 4.0 Hz, J = 14.6 Hz,
Compound 7 could not be isolated as a pure product and
was contaminated with a trace of a monobenzylated

H. Li et al. / Tetrahedron: Asymmetry 16 (2005) 313–319
319
1
derivative: H NMR (D2O, 400 MHz): 4.10–4.03 (m, 3H,
(C-2), 49.64 (C-1), 45.39 (C-7), 26.85 (CH3), 26.79 (CH3);
m/z (CI, NH3): 259 (M þ NHþ4 , 100%).
H-1, H-2, H-3), 3.90–3.75 (m, 3H, H-4, H-6a, H-6b), 3.71–
3.66 (m, 2H, H-5, H-7a), 3.43 (dd, 1H, H-7b), 13C NMR
(D2O, 100 MHz): 76.25, 76.05, 68.42, 58.36, 49.43 (C-1, C-
2, C-3, C-4, C-5), 60.75 (C-6) 45.18 (C-7); m/z (CI, NH3):
193 (M+H+, 100%).
22. Selected crystal structure data for 26; crystal system
orthorhombic; space group P212121; Z = 4; cell parame-
ters: a = 5.8997(9), b = 12.970(2), c = 15.2263(18), a = 90,
˚
b = 90, c = 90; radiation (MoKa) k = 0.71073 A; 155
Compound 8: [a]D = +5 (c 1, CH3OH);1H NMR (D2O,
400 MHz): 4.31 (dd, 1H, J = 3.4 Hz, J = 9.4 Hz, H-1), 4.28
(dd, 1H, J = 3.1 Hz, J = 6.1 Hz, H-3), 4.13 (d, 1H,
J = 6.1 Hz, H-4), 3.85 (m, 2H, H-6a, H-6b), 3.80 (m, 1H,
H-5), 3.72 (dd, 1H, J = 2.9 Hz, J = 9.9 Hz, H-2), 3.55 (dd,
1H, J = 3.4 Hz, J = 13.6 Hz, H-7a), 3.45 (dd, 1H,
J = 9.2 Hz, J = 13.6 Hz, H-7b); 13C NMR (D2O,
100 MHz): 67.57 (C-3, C-4), 62.31 (C-1), 60.77 (C-6),
56.15 (C-2), 55.58 (C-5), 48.24 (C-7); m/z (CI, NH3): 193
(M+H+, 100%); HRMS (CI, NH3): calcd for C7H17O4N2
(M+H+): 193.1188, found 193.1192.
variables for 1947 reflections; final R = 0.0699,
RW = 0.0761; Crystallographic data (excluding structure
factors) have been deposited at the Cambridge Crystallo-
graphic Data Centre as supplementary publication no
CCDC 255152. Copies of the data can be obtained free of
charge on application to CCDC, 12 Union Road, Cam-
bridge CB2 1EZ, UK [Fax: (internat.) +44 1223/336 033;
E-mail: deposit@ccdc.cam.ac.uk.
23. A known protocol was applied: Saul, R.; Chambers, J. P.;
Molyneux, R. J.; Elbein, A. D. Arch. Biochem. Biophys.
1983, 221, 593; Brandi, A.; Cicchi, S.; Cordero, F. M.;
Frignoli, B.; Goti, A.; Picasso, S.; Vogel, P. J. Org. Chem.
1995, 60, 6806–6812, We verified that the delay of
inhibitor/enzyme incubation did not affect the inhibition
measurements. Under standard conditions, optimal inhib-
itory activities were measured after 5 min of incubation.
24. Hiromi, K.; Kawai, M.; Ono, S. J. Biochem. 1966, 59, 476–
480.
Compound 26: [a]D = +21 (c 1.1, CHCl3); 1H NMR
(CDCl3, 400 MHz): 4.57 (dd, 1H, J = 6.3 Hz, J = 15.3 Hz,
H-7a), 4.52 (dd, 1H, J = 7.7 Hz, J = 9.2 Hz, H-6a), 4.31 (d,
1H, J = 5.0 Hz, J = 9.2 Hz, H-6b), 3.79 (dd, 1H,
J = 5.5 Hz, J = 9.2 Hz, H-3), 3.75 (t, 1H, J = 8.5 Hz, H-
4), 3.70 (dt, 1H, J = 5.0 Hz, J = 8.5 Hz, H-5), 3.40 (ddd,
1H, J = 4.8 Hz, J = 6.3 Hz, J = 7.8 Hz, H-1), 3.23 (t, 1H,
J = 4.8 Hz, H-2), 2.74 (dd, 1H, J = 7.8 Hz, J = 15.3 Hz, H-
7b), 1.50 (s, 3H, CH3), 1.43 (s, 3H, CH3); 13C NMR
(CDCl3, 100 MHz): 157.21 (C=O), 112.07 (C(CH3)2),
80.44 (C-3), 77.63 (C-4), 65.80 (C-6), 59.58 (C-5), 53.84
25. Meagher, M. M.; Reilly, P. J. Biotechnol. Bioeng. 1989, 34,
689–693.
26. Moris-Varas, F.; Qian, X.-H.; Wong, C.-H. J. Am. Chem.
Soc. 1996, 118, 7647–7652.