Parallel synthesis of a small library of novel aminoglycoside analogs based on 2-amino-2-deoxy-D-glucose and D-ribose scaffolds

Article abstract of DOI:10.1016/S0040-4020(01)00584-1

The synthesis of a small library of aminoglycoside analogues based on 2-amino-2-deoxy-D-glucose and D-ribose was achieved using reductive amination reactions as key transformations.

Full text of DOI:10.1016/S0040-4020(01)00584-1

TETRAHEDRON
Pergamon
Tetrahedron 57 (2001) 6277±6287
Parallel synthesis of a small library of novel aminoglycoside
analogs based on 2-amino-2-deoxy-d-glucose
and d-ribose scaffolds
Christoph Rosenbohm,a,² Dirk Vanden Berghe,b Arnold Vlietinckb and Jesper Wengela,p
aDepartment of Chemistry, University of Southern Denmark, Odense, DK-5230 Odense M, Denmark
bDepartment of Pharmaceutical Sciences, University of Antwerp, B-2610 Antwerp, Belgium
Received 21 March 2001; revised 1 May 2001; accepted 17 May 2001
AbstractÐThe synthesis of a small library of aminoglycoside analogues based on 2-amino-2-deoxy-d-glucose and d-ribose was achieved
using reductive amination reactions as key transformations. q 2001 Elsevier Science Ltd. All rights reserved.
1. Introduction
unit. The 2-deoxystreptamine is glycosylated with a variety
of saccharides both with and without amino groups at
the 4-position as well as the 5-position as in the neomycin
class, or at the 6-position as in the kanamycin±gentamicin
class.
The vast majority of the drugs known today owe their
pharmaceutical activity to interactions with proteins and
only very few rely on interactions with RNA. In the last
years the interest in RNA as a drug receptor has grown
signi®cantly due to the discovery that RNA is involved in
many catalytic processes1 and to the approval of the ®rst
antisense drug.2 The increased awareness of the central role
of RNA has led to research into small molecules that
interact with RNA. The potency of aminoglycoside anti-
biotics and the importance of circumventing the emerging
problems of resistance has led to studies on the mechanism
of action of these antibiotics focusing on understanding the
molecular interactions leading to activity.3 It was shown
early that aminoglycosides interact with the bacterial ribo-
some leading to miscoding and/or termination of growing
peptide chains.4 By using a foot-printing technique, Moazed
and Noller were the ®rst to describe the secondary structure
of the 16S rRNA5 subunit of the ribosome and later the site
of aminoglycoside binding to the A-site.6 The A-site
together with the P-site ensure the ®delity of tRNA selection
and the binding of aminoglycosides interferes with the
selection and proof-reading mechanism thereby lowering
the accuracy of protein synthesis. Chemically, the natural
aminoglycosides are a group of structurally related poly-
amine oligosaccharides (Fig. 1).7 Their common structural
element is a meso-1,3-diaminocyclitol 2-deoxystreptamine
Most of the information about the binding of aminoglyco-
sides to the 16S rRNA subunit has been obtained from two
NMR structures, one of the free As-wt oligonucleotide
model for the 16S rRNA subunit8 and one of a complex
between paromomycin and the As-wt.9 One of the striking
features of these structures is that it is the paromamine part
of paromomycin that is responsible for virtually all of the
speci®c hydrogen bonding contacts to the RNA. The two
other rings are apparently responsible for orienting the
paromamine/neamine part in an optimal way. Aminoglyco-
sides bind to a pocket in the bacterial 16S rRNA subunit
created by a mismatched base pair and to a host of other
RNA targets. Tok and Rando have furthermore shown that
simple 1,3-hydroxylamine containing aminols are also able
to bind the As-wt model with low micro molar af®nities
which is comparable to the binding af®nities of some of
the natural aminoglycosides.10 Further investigations on
the role of the different parts of the natural aminoglycosides
on binding have been performed by Alper et al.11 who have
synthesized a series of neomycin B analogues in which the
2,6-dideoxy-2,6-diamino-l-idose unit was replaced by
different groups. Further work by Wong and coworkers
has shown that 2-amino-2-deoxy-d-glucose12 and neamine13
are effective scaffolds for the synthesis of libraries of amino-
glycoside analogues with good RNA binding properties. A
differently structured library based on neamine in which the
60-amino group was functionalized by reductive aminations
or Ugi type couplings has been prepared in order to further
study RNA binding.14
Keywords: carbohydrate libraries; aminoglycoside analogues; 2-amino-2-
deoxy-d-glucose; reductive amination reactions.
Corresponding author. Tel.: 145-6550-2510; fax: 145-6615-8780;
e-mail: jwe@chem.sdu.dk
Present address: Cureon A/S, Fruebjergvej 3, DK-2100 Copenhagen,
Denmark.
p
²
0040±4020/01/$ - see front matter q 2001 Elsevier Science Ltd. All rights reserved.
PII: S0040-4020(01)00584-1

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C. Rosenbohm et al. / Tetrahedron 57 (2001) 6277±6287
Figure 1. Examples of the natural aminoglycosides.
2. Results and discussion
exploratory library we decided to use parallel solution phase
synthesis of individual compounds in order to facilitate
analysis of both reactions and preliminary biological
activities.
Based on the above outlined knowledge regarding the bind-
ing motifs and the functional groups which are important for
the interaction between aminoglycosides and the bacterial
ribosome A-site, we have designed and synthesized a series
of novel structurally simple aminoglycoside analogues and
studied their antibacterial activity (Fig. 2). The 2-amino
group was left free to mimic the natural aminoglycosides
and the 6-position was modi®ed with different amines by
various methods. The diversity was further increased by
allylation of the anomeric position followed by functionali-
zation by ozonolysis and reductive amination. In addition,
derivatives containing a ribose core were also included in
the library.15 In contrast to the known RNA-binding amino-
glycoside analogues all having a-glycosidic bonds to a
moiety containing an amino functionality, all the novel
compounds synthesised and investigated herein are
b-con®gured. However, we believed that the obtained
results should add novel knowledge to the structure±activity
relationship available for aminoglycoside analogues. For an
The synthesis of the core molecules 4 and 7 started with the
hydrochloride of 2-amino-2-deoxy-d-glucose (1) which was
®rst treated with 1.05 equiv. of triethylamine followed by
ethyl tri¯uoroacetate.16 Under these conditions the amino
group is chemoselectively tri¯uoroacetylated yielding
derivative 2. Without puri®cation, the tri¯uoroacetamide
derivative 2 was subjected to glycosidation in anhydrous
allyl alcohol at re¯ux for 8 h with boron tri¯uoride etherate
as Lewis acid catalyst. After complete conversion according
to analytical TLC, the reaction mixture was concentrated
and the residue coevaporated with anhydrous pyridine
before treatment with excess acetic anhydride in anhydrous
pyridine affording the fully protected allyl glucoside 4 after
puri®cation by column chromatography (b-glucoside, 47%
yield from 1). The b-con®guration of compounds 4±19 and
25±30 was assigned based on the J1,2 coupling constants
Figure 2. Design of the 1,6-disubstituted 2-amino-2-deoxy-d-glucose library.
Scheme 1. (a) Ethyl tri¯uoroacetate, Et3N, MeOH; (b) Allyl alcohol, BF3´OEt2 and (c) Ac2O, pyridine (47% from 1).

C. Rosenbohm et al. / Tetrahedron 57 (2001) 6277±6287
6279
Scheme 2. (a) TBDMSCl (1.1 equiv.), pyridine; (b) Ac2O, pyridine (50% from 1) and (c) I2, MeOH (86%).
1
observed in the H NMR spectra (J1,2ˆ<9 Hz) and the
chemical shift value observed in the 13C NMR spectra for
C1 (at <99 ppm) being in the typical range observed for
b-2-amino-2-deoxy-d-glycopyranosides17 (Scheme 1).
which an alkyl halide is treated with the sodium salt of
phthalimide. To obtain the free amine, the phthalimide is
then either hydrolyzed or cleaved with hydrazine. A similar
reaction was developed by Harland et al. and used by
Overman et al. in the total synthesis of strychnine. In this
reaction, an alkyl halide or similar is treated with the sodium
salt of tri¯uoroacetamide generated in situ by reacting
tri¯uoroacetamide with sodium hydride.20 The latter reac-
tion was attempted on 7 because it introduces the amine
already protected as the tri¯uoroacetamide group which,
as a similar group is already present in compound 7,
would eliminate an additional deprotection step. Three
different leaving groups were tested in the substitution
reaction, namely the mesyl, the tri¯ate and the iodo group,
but in all cases the substitution failed to give the desired
6-amino-6-deoxy-6-N-tri¯uoroacetyl derivative. A small
scale reaction, in which 7 was tosylated and then treated
with sodium azide in dimethylformamide yielded the
azide 10 (Scheme 3). Therefore, inspired by the success of
the selective silylation of compound 3, a selective tosylation
of this compound was performed. Thus, by treatment of
compound 3 with tosyl chloride in pyridine (to give inter-
mediate 8) followed by the addition of an excess of acetic
anhydride, compound 9 was obtained in 40% from 1
(Scheme 3) after column chromatographic puri®cation.
Compound 4 was now ready for the synthesis of parom-
amine-like compounds by ozonolysis of the allyl group
followed by reductive amination. In order to functionalize
the 6-position, the introduction of an orthogonal protection
group at this site was needed. Silyl ethers are well known
and much used in carbohydrate chemistry. When treating
compound 3 with 1.1 equiv. of TBDMSCl in pyridine,
monosilylation of the primary hydroxyl group was
achieved. When TLC showed complete conversion to 5,
4 equiv. of acetic anhydride were added to give derivative
6 which was obtained in 50% yield from 1 after puri®cation
by column chromatography (Scheme 2).
There is a wealth of methods available for the deprotection
of TBDMS ethers, among these are KF and 18-crown-6, HF
in pyridine, tri¯uoroacetic acid, HCl in ethanol, and
BF3´Et2O.18 Strongly acidic conditions, e.g. the use of
BF3´Et2O, were ruled out for the deprotection of 6 because
of the risk of deallylation and/or anomerisation. The most
common method for the deprotection of a silyl ether is the
treatment with excess ¯uoride ions usually provided in the
form of tetrabutylammonium ¯uoride (TBAF) because of
the solubility of this salt in most organic solvents. However,
even with a very large excess of ¯uoride (10 equiv.) and
long reaction times (.24 h) it was not possible to drive
the desilylation of compound 6 to completion. As an
alternative, compound 6 was treated with a 1% (w/v) solu-
tion of iodine in methanol19 at re¯ux for 3 h leading to clean
conversion of 6 giving compound 7 in 86% yield after
chromatographic puri®cation.
Heating tosylate 9 in dimethylformamide with an excess of
sodium azide afforded azide 10 in 76% yield. The tosylate 9
was also used for the reaction with the two secondary
amines N-methylpiperazine and N-Boc-piperazine. In the
®rst attempt, dimethylformamide was used as solvent but
with both amines none of the desired product was observed,
and heating only lead to decomposition and the formation of
dimethylamine.21 However, changing the solvent to pyri-
dine allowed the introduction of the two secondary amines
to proceed in moderate yields of 45% for 11 and 70% for 12
(Scheme 3).
Two different methods for the introduction of amines at the
6-position were investigated. The classical method for the
synthesis of primary amines is the Gabriel synthesis in
As an alternative method for the introduction of amines at
Scheme 3. (a) TsCl, pyridine; (b) Ac2O (40% from 1); (c) NaN3, DMF, 908C (76% for 10) and (d) N-methylpiperazine (45% for 11) or Boc-piperazine (70%
for 12), pyridine (908C).

6280
C. Rosenbohm et al. / Tetrahedron 57 (2001) 6277±6287
Scheme 4. (a) Oxalyl chloride, DMSO, TEA, CH2Cl2 (32%); (b) CrO3, Ac2O, pyridine, CH2Cl2 (92%); (c) NaCNBH3, AcOH, MeOH, amine (11: 25% and 12:
18%).
the 6-position of 2-amino-2-deoxy-d-glucose derivatives,
reductive amination reactions were studied (Scheme 4).
Oxidation of 7 with PDC22 only proceeded slowly (about
50% conversion after 7 days according to analytical TLC)
and a Swern oxidation23 did not afford more than 32% yield
of the desired aldehyde. However, oxidation with chrom-
(VI)oxide, pyridine, and acetic anhydride24 was successful
yielding the aldehyde 13 in 92% after ®ltration of the
reaction mixture through a plug of silica. The reductive
amination of aldehyde 13 with N-methylpiperazine and
N-Boc-piperazine proceeded in only poor yields (25% for
11 and 18% for 12) and were therefore abandoned.
In order to expand the library, a d-ribose moiety as found in
streptomycin, ribostamycin, and neomycin B was included.
The very ef®cient synthesis of the ketone 20 was known
from our previous work15 and this ketone was subjected to
reductive amination with both N-methylpiperazine and
N-Boc-piperazine (Scheme 6) yielding pairs of diastereo-
isomers. The reaction with N-methylpiperazine proceeded
in 49% yield (21/22ˆ1:1.2) whereas the reaction with
N-Boc-piperazine proceeded in 63% yield (23/24ˆ1:1.4).
The con®guration of the individual diastereoisomers was
1
assigned based on H±1H COSY, 1H±13C COSY and NOE
experiments. Especially important for the con®gurational
assignments were NOE contacts, or lack of the same,
between a-protons of the piperazine moieties and H-3 of
the ribose ring. Thus, the NOE experiment for 22 showed
mutual and strong contacts between the a-protons of the
piperazine ring and H-3. No such NOE contacts were
observed for compound 21. A similar pattern was seen for
the diastereoisomeric pair 23 and 24.
Compounds 4, 10, and 11 were subjected to ozonolysis of
the allyl side chain in order to unmask an aldehyde for
reductive amination reactions (Scheme 5). The reductive
aminations to give the compound 17 and 18 shown in
Scheme 5 proceeded in 34±85% yield which is within
the normal range for this type of reaction.25 Derivatives
19 were only obtained in very poor yields. Mattson et
al.26 have observed improvement in yields of reductive
amination reactions by using titanium(IV)isopropoxide as
Lewis acid but in this case the yields of 19 were not
increased.
All the library compounds were ®nally deprotected, and
depending on the protecting groups present different conditions
had to be employed (Scheme 7). Complete deprotection was
Scheme 5. (a) O3, MeOH, 2788C, CH3SCH3; (b) N-methylpiperazine or N-Boc-piperazine, NaCNBH3, AcOH, MeOH.
Scheme 6. (a) N-methylpiperazine or N-Boc-piperazine, NaCNBH3, AcOH, MeOH.

C. Rosenbohm et al. / Tetrahedron 57 (2001) 6277±6287
6281
Scheme 7. (a) CF3COOH; (b) NH3, MeOH; (c) H2, 20% Pd(OH)2/C, 1:1 EtOH/dioxane and (d) TBAF, THF.
carried out with no puri®cation between the individual
steps, and the completely deprotected compounds 25±34
were puri®ed by cation-exchange chromatography using
ammonium hydroxide/water as eluent. The pure compounds
were converted into their hydrochloride salts by adding an
excess of 1 M hydrochloric acid followed by lyophilization
to give off-white powders.
reductive amination reactions. Only weak antiviral activities
were obtained, and only for a few of the compounds
evaluated.
4. Experimental
4.1. General
Compounds 25±34 were obtained in good yields and in
excellent purities as veri®ed by mass spectrometry and
NMR spectroscopy. In the present study, compounds 25±
34 were tested for their potential antibacterial, antifungal
and antiviral properties by in vitro standard methods.27 All
compounds showed minimum inhibitory concentrations
(MIC), minimum bactericidal concentrations (MBC) and
minimum fungicidal concentrations (MFC) higher than
100 mg/ml. Some of the compounds showed weak antiviral
properties against herpes simplex virus type 1 (HSV-1)
(compounds 31, 32 and 33), Semliki forest virus L10
(compounds 33 and 34) and vesicular stomatitis virus
(VSV) (compound 33) in concentrations of 100±50 mg/ml.
All reagents were obtained from commercial suppliers and
were used without further puri®cation. Silica gel (0.040±
0.063 mm) used for column chromatography was purchased
from Merck. FAB mass spectra were recorded on a Kratos
MS 50 RF spectrometer, EI mass spectra on a Varian Mat
311A spectrometer, and NMR spectra on a Varian Gemini
2000 spectrometer (d-values are reported relative to Me4Si
as internal reference for 1H NMR (300 MHz) and 13C NMR
(62.9 MHz) whereas 1,4-dioxane was used as internal
reference for 13C NMR recorded in D2O). The atoms
numbered 1±6 for compounds 4±19 and 25±30 denote the
pyranose ring (using standard carbohydrate nomenclature)
with subsequent numbering of the atoms of the O1 sub-
stituent and, when applicable, the C6 substituent. The
atoms numbered 1±5 for compounds 21±24 and 31±34
denote the furanose ring (using standard carbohydrate
nomenclature) with subsequent numbering of the atoms of
the C2 substituent. In the 13C NMR spectra of the tri¯uoro-
acetamido derivatives the signals of the tri¯uoroacetyl
3. Conclusion
The synthesis of a small library of aminoglycoside ana-
logues based on 2-amino-2-deoxy-d-glucose and d-ribose
was achieved by applying nucleophilic substitution and

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C. Rosenbohm et al. / Tetrahedron 57 (2001) 6277±6287
group were detectable in some cases and in others not as
re¯ected in the data reported for the individual compounds.
Microanalyses were performed at the Microanalytical
Laboratory, Department of Chemistry, University of
Copenhagen.
redissolved in DCM (100 ml) and washed with a saturated
aqueous solution of NaHCO3 (3£100 ml). The organic
phase was separated, dried (Na2SO4) and evaporated under
reduced pressure. The residue was puri®ed by column
chromatography using 0±4% MeOH in DCM (v/v) as eluent
to afford compound 6 (6.42 g, 50%) as a white solid
1
4.1.1. Allyl 3,4,6-tri-O-acetyl-2-deoxy-2-tri¯uoroaceta-
mido-b-d-glucopyranoside (4). 2-Amino-2-deoxy-d-
glucose as its hydrochloride salt 1 (5.39 g, 25 mmol) was
suspended in methanol (25 ml) and triethylamine (3.57 ml,
26.2 mmol) was added followed by ethyl tri¯uoroacetate
(3.27 ml, 27.5 mmol) and the solution was stirred for 18 h
at rt. The solution was concentrated in vacuo and the result-
ing oil coevaporated three times with anhydrous allyl
alcohol. The resulting gum was dissolved in anhydrous
allyl alcohol (40 ml) and BF3´Et2O (0.5 ml) was added
and the solution was heated under re¯ux for 8 h. The solvent
was removed and the residue was coevaporated three times
with anhydrous pyridine. The residue was dissolved in
anhydrous pyridine (40 ml) and acetic anhydride (14.03
ml, 150 mmol) was added and the mixture was stirred for
30 min at rt. The solvent was removed under reduced
pressure, the resulting oil was redissolved in DCM
(100 ml) and washed with a saturated aqueous solution of
NaHCO3 (3£100 ml). The organic phase was separated,
dried (Na2SO4) and evaporated under reduced pressure.
The residue was puri®ed by column chromatography
using 0±4% MeOH in DCM (v/v) as eluent to afford
material. H NMR (CDCl3) d: 6.42 (br. s, 1H, NH), 5.88±
5.76 (m, 1H, H8), 5.31±5.17 (m, 3H, H3, H9), 5.02 (t, Jˆ
9.8 Hz, 1H, H4), 4.59 (d, Jˆ8.2 Hz, 1H, H1), 4.32 (ddt,
Jˆ13.2, 4.8, 1.5 Hz, 1H, H2), 4.11±3.99 (m, 2H, H7),
3.70 (d, Jˆ4.5 Hz, 2H, H6), 3.59±3.53 (m, 1H, H5), 2.02
(s, 6H, 2£CH3CO), 0.95±0.82 (m, 9H, SiC(CH3)3), 0.11±
0.01 (m, 6H, Si(CH3)2); 13C NMR (CDCl3) d: 171.6, 169.4
(2£CH3CO); 157.2 (q, Jˆ37.5 Hz, CF3CO), 133.3 (C8),
118.0 (C9), 98.9 (C1), 74.9 (C5), 72.3 (C7), 69.4 (C3),
68.9 (C4), 62.5 (C6), 54.7 (C2), 25.5 (C(CH3)3), 20.6,
20.3 (2£CH3CO), 18.2 (C(CH3)3), 25.5 (SiMe); 19F NMR
(CDCl3) d: 116.0. MS (FAB1/NBA) m/z: 512 ([M]1).
Found C: 48.89 H: 6.57 N: 2.73; C21H34F3NO8Si requires
C: 49.11 H: 6.67 N: 2.73.
4.1.3. Allyl 3,4-di-O-acetyl-2-deoxy-2-tri¯uoroaceta-
mido-b-d-glucopyranoside (7). Glucoside
6 (1.66 g,
3.24 mmol) was dissolved in methanol (20 ml) and a 1%
(w/v) solution of iodine in methanol (150 ml) was added.
The solution was heated under re¯ux for 3 h whereupon the
reaction was quenched by addition of 1 M Na2S2O3
(aqueous) until decolorization was observed. The solvents
were removed in vacuo and the resulting oil was taken up in
DCM, washed with brine, separated, dried (Na2SO4) and
evaporated under reduced pressure. The residue was
puri®ed by column chromatography using 5% MeOH in
DCM (v/v) as eluent to afford compound 7 (1.19 g, 92%)
1
compound 4 (5.20 g, 47%) as a white solid material. H
NMR (CDCl3) d: 6.88 (br. s, 1H, NH), 5.88±5.73 (m, 1H,
H8), 5.34 (d, Jˆ10.0 Hz, 1H, H3), 5.29±5.15 (m, 2H, H9),
5.08 (t, Jˆ10 Hz, 1H, H4), 4.67 (d, Jˆ8.2 Hz, 1H, H1),
4.37±4.27 (m, 1H, H70), 4.24 (d, Jˆ4.9 Hz, 1H, H60),
4.17 (d, Jˆ2.5 Hz, 1H, H600), 4.14±4.08 (m, 1H, H700),
4.05±3.99 (m, 1H, H2), 3.76±3.71 (m, 1H, H5), 2.08 (s,
3H, CH3CO), 2.02 (s, 6H, 2£CH3CO); 13C NMR (CDCl3)
d: 171.4, 170.9, 169.5 (3£CH3CO); 157.5 (q, Jˆ37.5 Hz,
CF3CO), 133.1 (C8), 118.2 (C), 116.1 (q, Jˆ262.5 Hz,
CF3CO), 99.1 (C1), 71.8 (C7, C5), 70.1 (C3), 68.5 (C4),
62.0 (C6), 54.7 (C2), 20.5, 20.4, 20.2 (3£CH3CO); 19F
NMR (CDCl3) d: 116.0. MS (FAB1/NBA) m/z: 384 ([M2
(Oallyl)]1). Found C: 46.23 H: 5.01 N: 3.11; C17H22F3NO9
requires C: 46.30 H: 5.02 N: 3.17.
1
as a white solid material. H NMR (CDCl3) d: 5.83±5.69
(m, 1H, H8), 5.27±5.12 (m, 3H, H3, H9), 5.01±4.94 (m, 1H,
H4), 4.65 (d, Jˆ8.2 Hz, 1H, H1), 4.32 (dd, Jˆ13.2, 5.2 Hz,
1H, H2), 4.08±3.93 (m, 2H, H7), 3.67±3.49 (m, 3H, H6,
H5), 2.02 (s, 3H, CH3CO), 1.96 (s, 3H, CH3CO); 13C NMR
(CDCl3) d: 171.2, 170.3 (2£CH3CO), 133.3 (C8), 117.7
(C9), 99.1 (C1), 74.0 (C5), 71.9 (C7), 70.1 (C3), 68.8
(C4), 60.9 (C6), 54.3 (C2), 20.4, 20.2 (2£CH3CO); 19F
NMR (CDCl3) d: 116.2. MS (FAB1/NBA) m/z: 342
([M2Oallyl]1). Found C: 44.89 H: 4.78 N: 3.29;
C15H20F3NO8 requires C: 45.12 H: 5.05 N: 3.51.
4.1.2. Allyl 3,4-di-O-acetyl-6-O-(t-butyldimethylsilyl)-2-
deoxy-2-tri¯uoroacetamido-b-d-glycopyranoside
(6).
4.1.4. Allyl 3,4-di-O-acetyl-2-deoxy-2-tri¯uoroaceta-
mido-6-O-tosyl-b-d-glucopyranoside (9). 2-Amino-2-
deoxy-d-glucose as its hydrochloride salt 1 (10.78 g,
50 mmol) was suspended in methanol (50 ml) and triethyl-
amine (7.15 ml, 52.5 mmol) was added followed by ethyl
tri¯uoroacetate (6.54 ml, 55 mmol) and the solution was
stirred for 18 h at rt. The solution was concentrated in
vacuo and the resulting oil coevaporated three times with
anhydrous allyl alcohol. The resulting gum was dissolved in
anhydrous allyl alcohol (75 ml) and BF3´Et2O (1.0 ml) was
added and the solution was heated under re¯ux for 8 h. The
solvent was removed and the residue was coevaporated
three times with anhydrous pyridine. The residue was
dissolved in anhydrous pyridine (75 ml) and tosyl chloride
(11.4 g, 60.0 mmol) was added and when TLC showed
complete conversion after 3 h at rt acetic anhydride
(10.29 ml, 110 mmol) was added and the mixture was
stirred for further 30 min at rt. The solvent was removed
2-Amino-2-deoxy-d-glucose as its hydrochloride salt 1
(5.39 g, 25 mmol) was suspended in methanol (25 ml) and
triethylamine (3.57 ml, 26.2 mmol) was added followed by
ethyl tri¯uoroacetate (3.27 ml, 27.5 mmol) and the solution
was stirred for 18 h at rt. The solution was concentrated in
vacuo and the resulting oil coevaporated three times with
anhydrous allyl alcohol. The resulting gum was dissolved in
anhydrous allyl alcohol (40 ml) and BF3´Et2O (0.5 ml) was
added and the solution was heated under re¯ux for 8 h. The
solvent was removed and the residue was coevaporated
three times with anhydrous pyridine. The resulting oil was
dissolved in anhydrous pyridine (40 ml) and t-butyldi-
methylsilyl chloride (4.14 g, 27.5 mmol) was added and
when TLC showed complete conversion after 16 h at rt
acetic anhydride (9.35 ml, 100 mmol) was added and the
mixture was stirred for 30 min at rt. The solvent was
removed under reduced pressure, the resulting oil was

C. Rosenbohm et al. / Tetrahedron 57 (2001) 6277±6287
6283
under reduced pressure, the resulting oil was redissolved
in DCM (100 ml) and washed with a saturated aqueous
solution of NaHCO3 (3£100 ml). The organic phase was
separated, dried (Na2SO4) and evaporated under reduced
pressure. The residue was puri®ed by column chroma-
tography ®rst using 0±2% MeOH in DCM (v/v) and then
20±50% EtOAc in petroleum ether (v/v) as eluents to yield
compound 9 (11.07 g, 40%) as an off-white solid material.
1H NMR (CDCl3) d: 7.77 (d, Jˆ8.3 Hz, 2H, H20(Ts)), 7.34
(d, Jˆ8.0 Hz, 2H, H30(Ts)), 7.00 (d, Jˆ9.2 Hz, 1H, NH),
5.85±5.71 (m, 1H, H8), 5.35±5.20 (m, 3H, H3, H9), 4.93
(app. t, Jˆ9.8 Hz, 1H, H4), 4.63 (d, Jˆ9.8 Hz, 1H, H1),
4.28±3.95 (m, 5H, H7, H6, H2), 3.85±3.79 (m, 1H, H5),
2.44 (s, 3H, CH3 (Ts)) 2.01 (br. s, 6H, 2£CH3CO); 13C NMR
(CDCl3) d: 171.4, 169.7 (2£CH3CO); 157.5 (q, Jˆ36 Hz,
CF3CO), 145.4 (C10(Ts)), 133.0 (C8), 134.4 (C40(Ts)),
130.0 (C20(Ts)), 128.1 (C30(Ts)), 118.1 (C9), 115.9 (q,
Jˆ255 Hz, CF3CO), 98.9 (C1), 71.7 (C5, C6), 69.9 (C3),
68.8 (C7), 67.9 (C4), 54.4 (C2), 21.5 (CH3(Ts)), 20.6, 20.3
(2£CH3CO), 19F NMR (CDCl3) d: 115.9. MS (FAB1/NBA)
m/z: 496 ([M2Oallyl]1). Found C: 47.99 H: 4.50 N: 2.54;
C22H26F3NSO10 requires C: 47.73 H: 4.73 N: 2.53.
(CDCl3) d: 7.19 (d, Jˆ8.8 Hz, 1H, NH), 5.86±5.73 (m, 1H,
H8), 5.31±5.13 (m, 3H, H3, H9), 4.98 (app. t, Jˆ9.4 Hz,
1H, H4), 4.60 (d, Jˆ8.3 Hz, 1H, H1), 4.26 (dd, Jˆ13.1,
4.9 Hz, 1H, H5), 4.05±3.92 (m, 3H, H7, H6), 3.69±3.60
(m, 1H, H2), 2.45±2.31 (m, 8H, CH2-pip), 2.24 (s, 3H,
Me-pip), 2.00 (br. s, 6H, 2£CH3CO); 13C NMR (CDCl3)
d: 171.4, 169.6 (2£CH3CO), 157.5 (q, Jˆ33 Hz, CF3CO),
133.2 (C8), 117.9 (C9), 115.6 (q, Jˆ287 Hz, CF3CO), 98.9
(C1), 73.6, 72.9 (C5, C3), 70.5, 69.9 (C7, C4), 58.5 (C6),
55.0 (C10), 54.7 (C2), 53.6 (C11), 45.8 (C12), 20.7, 20.3
(2£CH3CO); 19F NMR (CDCl3) d: 116.2. MS (FAB1/NBA)
m/z: 482 ([M]1). Found C: 49.67 H: 6.14 N: 8.68;
C20H30F3N3O7 requires C: 49.90 H: 6.28 N: 8.73.
4.1.7. Allyl 3,4-di-O-acetyl-6-(N-t-butoxycarbonyl)pipera-
zino-2,6-dideoxy-2-tri¯uoroacetamido-b-d-glucopyrano-
side (12). Glucoside 9 (553 mg, 1.00 mmol) was dissolved
in anhydrous pyridine (25 ml) and N-(t-butoxycarbonyl)-
piperazine (279.0 mg, 3.0 mmol) was added. The solution
was stirred at 908C for 10 h. The solvent was removed under
reduced pressure, and the resulting oil was redissolved in
EtOAc (25 ml) and washed with brine (3£25 ml). The
organic phase was separated, dried (Na2SO4), and evapo-
rated under reduced pressure. The residue was puri®ed by
column chromatography using 2±5% MeOH in DCM (v/v)
as eluent to afford compound 12 (198 mg, 70%) as a clear
oil. 1H NMR (CDCl3) d: 5.86±5.75 (m, 1H, H8), 5.29±5.15
(m, 3H, H3, H9), 5.00 (app. t, Jˆ9.6 Hz, 1H, H4), 4.66 (d,
Jˆ8.1 Hz, 1H, H1), 4.32±4.25 (m, 1H, H5), 4.06±3.92 (m,
2H, H7), 3.67±3.61 (m, 1H, H2), 3.57±3.42 (m, 2H, H6),
2.43 (d, Jˆ2.7 Hz, 4H, CH2-pip), 2.15±2.04 (m, 4H, CH2-
4.1.5. Allyl 3,4-di-O-acetyl-6-azido-2,6-dideoxy-2-tri-
¯uoroacetamido-b-d-glucopyranoside (10). Derivative 9
(1.00 g, 1.81 mmol) was dissolved in anhydrous DMF
(50 ml) and NaN3 (352 mg, 5.42 mmol) was added. The
solution was stirred at 908C for 3 h. The solvent was
removed under reduced pressure, and the resulting oil was
redissolved in EtOAc (50 ml) and washed with brine
(3£50 ml). The organic phase was separated, dried
(Na2SO4), and evaporated under reduced pressure. The
residue was puri®ed by column chromatography using
20% EtOAc in petroleum ether (v/v) as eluent to afford
compound 10 (589 mg, 76%) as a clear oil. 1H NMR
(CDCl3) d: 6.93 (d, Jˆ8.9 Hz, 1H, NH), 5.89±5.76 (m,
1H, H8), 5.37±5.22 (m, 3H, H3, H9), 4.98 (app. t, Jˆ
9.5 Hz, 1H, H4), 4.71 (d, Jˆ8.2 Hz 1H, H1), 4.35 (dd,
Jˆ12.9, 3.8 Hz, 1H, H5), 4.13±4.03 (m, 2H, H7), 3.43
(dd, Jˆ13.4, 7.5 Hz, 1H, H6)), 3.20 (dd, Jˆ13.5, 1.75 Hz,
1H, H6), 2.03 (br. s, 6H, 2£CH3CO); 13C NMR (CDCl3) d:
171.4, 169.7 (2£CH3CO); 157.5 (q, Jˆ33 Hz, CF3CO),
133.0 (C8), 118.3 (C9), 115.6 (q, Jˆ287 Hz, CF3CO),
98.8 (C1), 73.7 (C5), 71.6 (C3), 69.9, 69.7 (C7, C4), 54.7
(C6) 51.1 (C2), 20.5, 20.4 (2£CH3CO), 19F NMR (CDCl3)
d: 116.2. MS (FAB1/NBA) m/z: 367 ([M2Oallyl]1). IR
(KBr): 3405, 3305, 3115, 2930, 2873, 2102, 1752, 1708,
1566, 1433, 1376, 1325, 1258, 1218, 1183, 1073, 1045,
994, 931, 895, 734 cm21. Found C: 42.58 H: 4.60 N:
13.33; C15H19F3N4O7 requires C: 42.46 H: 4.51 N: 13.20.
pip), 2.00 (br. s, 6H, 2£CH3CO), 1.44 (s, 9H, (C(CH3)3); 13
C
NMR (CDCl3) d: 170.9, 169.6 (2£CH3CO), 154.6(NCOO),
133.2 (C8), 117.9 (C9), 99.0 (C1), 72.7, 71.9 (C5, C3), 70.4,
70.0 (C7, C4), 58.6 (C6), 54.8 (C2), 53.7 (C10), 43.6 (br.
peak, C11), 29.2 (C(CH3)3), 20.7, 20.3 (2£CH3CO); 19F
NMR (CDCl3) d: 116.3. MS (FAB1/NBA) m/z: 568
([M]1). Found C: 50.50 H: 6.13 N: 7.29; C20H30F3N3O7
requires C: 50.79 H: 6.39 N: 7.40.
4.2. General procedure for the ozonolysis reactions
The starting allyl glucoside was dissolved in anhydrous
MeOH (30 ml/mmol starting allyl glucoside). After cooling
to 2788C, purging with O2 followed by O3 was performed
until a blue color appeared which was followed by purging
once more with O2. Dimethylsul®de (0.5 ml/mmol starting
allyl glucoside) was added and the temperature was allowed
to rise to rt. The resulting mixture was concentrated and
dried in high vacuum overnight. The crude material
obtained by this procedure was pure enough to be used
directly in the reductive amination reactions.
4.1.6. Allyl 3,4-di-O-acetyl-2,6-dideoxy-6-(N-methyl-
piperazino)-2-tri¯uoroacetamido-b-d-glucopyranoside
(11). Glucoside 9 (553 mg, 1.00 mmol) was dissolved in
anhydrous pyridine (25 ml) and N-methylpiperazine
(0.33 ml, 3.0 mmol) was added. The solution was stirred
at 908C for 7 h. The solvent was removed under reduced
pressure, and the resulting oil was redissolved in EtOAc
(25 ml) and washed with brine (3£25 ml). The organic
phase was separated, dried (Na2SO4), and evaporated
under reduced pressure. The residue was puri®ed by column
chromatography using 2±5% MeOH in DCM (v/v) as eluent
to yield compound 11 (217 mg, 45%) as a clear oil. 1H NMR
4.3. General procedure for the reductive amination
reactions
The carbonyl compound was dissolved in anhydrous MeOH
(8 ml/1.0 mmol carbonyl compound) followed by addition
of a 1.0 M solution of the amine (3 equiv.) in MeOH. Subse-
quently, a 1.0 M solution of AcOH (4 equiv.) in anhydrous
MeOH and a 0.3 M solution of NaCNBH3 (0.44 equiv.) in
MeOH were added. The resulting mixture was stirred under
Ar for 18 h at rt whereupon H2O (0.2 ml) was added. The

6284
C. Rosenbohm et al. / Tetrahedron 57 (2001) 6277±6287
resulting mixture was stirred for 20 min at rt followed by
evaporation under reduced pressure and addition of brine.
This mixture was extracted with DCM two or three times,
the organic phases combined, dried (Na2SO4), and evapo-
rated under reduced pressure. The residue was puri®ed by
column chromatography using 0±2% MeOH in DCM (v/v)
as eluent to afford the products as white solid materials.
(d, Jˆ8.5 Hz, 1H, H1), 4.02±3.93 (m, 2H, H2, H5), 3.74±
3.63 (m, 2H, H7), 3.37 (t, Jˆ3.6 Hz, 4H, H10), 3.21±3.16
(m, 2H, H6), 2.62±2.58 (m, 2H, H8), 2.41 (t, Jˆ4.6 Hz, 4H,
H9), 2.01 (s, 3H, CH3CO), 1.99 (s, 3H, CH3CO); 13C NMR
(CDCl3) d: 170.9, 169.6 (2£CH3CO), 154.8 (NCOO), 99.7
(C1), 79.7 (C12), 73.7, 71.6 (C3, C5), 69.7 (C4), 67.0 (C7),
57.3 (C8), 54.6 (C6), 53.3 (C2), 51.0 (C9), 42.8 (C10), 28.1
(C14), 20.4, 20.2 (2£CH3CO); 19F NMR (CDCl3) d: 116.1.
MS (FAB1/NBA) m/z: 597 ([MH]1).
4.3.1. 2-(N-Methylpiperazino)ethyl 3,4,6-tri-O-acetyl-2-
deoxy-2-tri¯uoroacetamido-b-d-glucopyranoside (17a).
Yield: 52 mg (55%) which was used in the next step without
further puri®cation. 1H NMR (CDCl3) d: 6.82 (d, Jˆ
11.0 Hz, 1H, NH), 5.44 (app. t, Jˆ8.3 Hz, 1H, H3), 5.18
(app. t, Jˆ9.0 Hz, 1H, H4), 4.90 (d, Jˆ8.3 Hz, 1H, H1),
4.40 (dd, Jˆ11.9, 4.1 Hz, 1H, H6), 4.21 (dd, Jˆ12.1,
2.2 Hz, 1H, H6b), 4.15±4.00 (m, 2H, H7), 3.82±3.74 (m,
2H, H5, H2), 3.20 (br. s, 4H, H10), 3.00 (br. s, 2H, H8),
2.65±2.50 (m, 4H, H9), 2.22 (s, 3H, H11), 2.06 (br. s, 9H,
3£H3CO); 13C NMR (CDCl3) d: 170.8, 170.7, 169.5 (3£
CH3CO), 99.5 (C1), 72.3, 71.9 (C3, C5), 68.4 (C4), 65.7
(C7), 61.9 (C6), 56.0 (C8), 54.3 (C2), 52.8 (C9), 45.9
(C11), 43.7 (C10), 20.5, 20.3, 20.2 (3£CH3CO); 19F NMR
(CDCl3) d: 115.9. MS (FAB1/NBA) m/z: 528 ([MH]1).
4.3.5. 1,2-Dideoxy-2-(N-methylpiperazino)-3-O,5-O-(tetra-
isopropyldisiloxan-1,3-diyl)-d-ribofuranose (21). Yield:
50 mg (21%) which was used in the next step without
1
further puri®cation. H NMR (DMSO-d6) d: 4.23 (app. t,
Jˆ5.7 Hz, 1H, H4), 3.89±3.72 (m, 4H, H1, H2, H50), 3.59±
3.53 (m, 1H, H5), 3.03 (app. q, Jˆ5.9 Hz, 1H, H3), 2.49 (br.
s, 4H, H7), 2.47±2.44 (m, 2H, H6), 2.40±2.26 (br. s, 2H,
i
H6), 2.11 (s, 3H, H8), 1.03±0.85 (m, 28H, Pr); 13C NMR
(DMSO-d6) d: 83.7 (C2), 75.1 (C4), 71.7 (C3), 66.3 (C1),
62.4 (C5), 54.8 (C7), 49.8 (C6), 45.6 (C8), 17.1, 17.0, 16.8,
13.1, 12.9, 12.8, 12.6 (iPr). MS (FAB1/NBA) m/z: 459
([M]1).
4.3.6. 1,2-Dideoxy-2-(N-methylpiperazino)-3-O,5-O-(tetra-
isopropyldisiloxan-1,3-diyl)-d-arabinofuranose
4.3.2. 2-(N-(t-Butoxycarbonyl)piperazino)ethyl 3,4,6-tri-
O-acetyl-2-deoxy-2-tri¯uoroacetamido-b-d-glucopyrano-
side (17b). Yield: 96 mg (47%) which was used in the next
step without further puri®cation. d: 6.90 (d, Jˆ12.0 Hz, 1H,
NH), 5.24 (app. t, Jˆ9.3 Hz, 1H, H3), 5.06 (app. t, Jˆ
9.7 Hz, 1H, H4), 4.70 (d, Jˆ8.4 Hz, 1H, H1), 4.25 (dd,
Jˆ12.2, 4.6 Hz, 1H, H6), 4.11 (dd, Jˆ12.5, 2.4 Hz, 1H,
H6), 4.06±4.00 (m, 2H, H7), 3.82±3.75 (m, 1H, H5), 3.70
(app. dq, Jˆ9.9, 2.3 Hz, 1H, H2), 3.43 (br. s, 4H, H10), 2.72
(t, Jˆ4.6 Hz, 2H, H8), 2.66±2.50 (m, 4H, H9), 2.01 (br. s,
9H, 3£CH3CO), 1.43 (s, 9H, (C(CH3)3); 13C NMR (CDCl3)
d: 170.8, 170.7, 169.5 (3£CH3CO); 157.5 (m, CF3CO),
154.6 (NCOO), 116.2 (q, Jˆ264 Hz, CF3CO), 99.9 (C1),
80.1 (C(CH3)3), 72.1, 72.1 (C3, C5), 68.3 (C4), 66.6 (C7),
61.3 (C6), 57.5 (C8), 54.4 (C2), 53.0 (C9), 43.0 (C10), 28.2
(C(CH3)3), 20.3, 20.3, 20.2 (3£iH3CO); 19F NMR (CDCl3)
d: 116.2. MS (FAB1/NBA) m/z: 614 ([MH]1).
(22).
Yield: 67 mg (28%) which was used in the next step without
further puri®cation. 1H NMR (CDCl3) d: 1H NMR (DMSO-
d6) d: 4.35 (app. t, Jˆ4.9 Hz, 1H, H4), 3.92±3.82 (m, 2H,
H1), 3.81±3.76 (m, 1H, H2), 3.73±3.61 (m, 2H, H5), 2.92
(app. q, Jˆ6.5 Hz, 1H, H3), 2.76 (br. s, 2H, H7), 2.59 (br. s,
2H, H7), 2.28 (br s, 4H, H6), 2.13 (s, 3H, H8), 1.04±0.87
(m, 28H, iPr); 13C NMR (DMSO-d6) d: 85.1 (C2), 74.9 (C4),
68.1 (C3), 65.6 (C1), 63.8 (C5), 55.1 (C7), 50.5 (C6), 45.8
(C8), 17.3, 17.1, 16.9, 16.8, 12.9, 12.8, 12.3, 11.9 (iPr). MS
(FAB1/NBA) m/z: 459 ([M]1).
4.3.7. 1,2-Dideoxy-2-(N-(t-butoxycarbonyl)piperazino)-
3-O,5-O-(tetraisopropylidisiloxan-1,3-diyl)-d-ribofura-
nose (23). Yield: 240 mg (26%). 1H NMR (CDCl3) d: 4.34
(app. t, Jˆ5.9 Hz, 1H, H4), 3.97 (dd, Jˆ11.9, 3.7 Hz, 1H,
H1), 3.89±3.78 (m, 3H, H1, H2, H5), 3.74±3.69 (m, 1H,
H5), 3.39 (t, Jˆ4.7 Hz, 4H, H7), 3.39 (app. q, Jˆ6.0 Hz,
1H, H3), 2.61±2.56 (m, 2H, H6), 2.43±2.37 (m, 2H, H6),
1.44 (s, 9H, H9), 1.07±0.91 (m 28H, iPr); 13C NMR (CDCl3)
d: 154.9 (NCOO), 84.8 (C2), 79.7 (C(CH3)3), 75.5 (C4),
72.8 (C3), 67.6 (C1), 62.9 (C5), 50.5 (C6), 44.2 (br, C7),
28.8 ((C(CH3)3), 17.3, 17.1, 16.9, 16.8, 13.7, 12.9, 12.8, 12.3
(iPr). MS (FAB1/NBA) m/z: 545 ([M]1). Found C: 56.95 H:
9.54 N: 4.94; C26H52N2O6Si2 requires C: 57.27 H: 9.62 N:
5.14.
4.3.3. 2-(N-Methylpiperazino)ethyl 3,4-di-O-acetyl-6-
azido-2,6-dideoxy-2-tri¯uoroacetamido-b-d-glucopyrano-
side (18a). Yield: 152 mg (85%) which was used in the next
1
step without further puri®cation. H NMR (CDCl3) d: 5.28
(app. t, Jˆ9.4 Hz, 1H, H3), 4.96 (app. t, Jˆ9.8 Hz, 1H, H4),
4.82 (d, Jˆ8.4 Hz, 1H, H1), 4.05±3.96 (m, 2H, H2, H5),
3.88±3.81 (m, 1H, H7), 3.76±3.70 (m, 1H, H7), 3.49±3.37
(m, 1H, H6), 3.19±3.14 (m, 1H, H6), 2.97±2.73 (m, 10H,
H8, H9, H10), 2.43 (s, 3H, H11), 2.02 (br. s, 6H, 2£
CH3CO); 13C NMR (CDCl3) d: 170.6, 169.7 (2£CH3CO),
99.6 (C1), 74.0, 72.0 (C3, C5), 69.7 (C4), 66.1 (C7), 56.1
(C8), 54.4 (C6), 53.3 (C2), 51.1 (C9), 50.7 (C10), 44.4
(C11), 20.5, 20.3 (2£CH3CO); 19F NMR (CDCl3) d:
116.0. MS (FAB1/NBA) m/z: 511 ([MH]1).
4.3.8. 1,2-Dideoxy-2-(N-(t-butoxycarbonyl)piperazino)-
3-O,5-O-(tetraisopropyldisiloxan-1,3-diyl)-d-arabino-
furanose (24). Yield: 344 mg (37%). H NMR (CDCl3) d:
1
4.43 (app. t, Jˆ5.8 Hz, 1H, H4), 4.03±3.99 (m, 1H, H2),
3.98±3.92 (m, 2H, H5), 3.89±3.84 (m, 1H, H1), 3.70 (dd,
Jˆ10.9, 7.5 Hz, 1H, H1), 3.42 (br s, 4H, H7), 2.97 (app. q,
Jˆ6.6 Hz, 1H, H3), 2.85±2.82 (m, 2H, H6), 2.68±2.61 (m,
4.3.4. 2-(N-(t-Butoxycarbonyl)piperazino)ethyl 3,4-di-O-
acetyl-6-azido-2,6-dideoxy-2-tri¯uoroacetamido-b-d-
glucopyranoside (18b). Yield: 115 mg (55%) which was
i
2H, H6), 1.47 (s, 9H, H9), 1.17±1.00 (m, 28H, Pr); 13C
NMR (CDCl3) d: 154.8 (NCOO), 85.2 (C2), 79.5
(C(CH3)3), 75.1 (C4), 68.9 (C1), 66.4 (C3), 64.0 (C5),
51.0 (C6), 44.8 (br, C7), 28.7 ((C(CH3)3), 17.3, 17.1, 17.0,
16.9, 13.5, 12.9, 12.8, 12.5 (iPr). MS (FAB1/NBA) m/z: 545
1
used in the next step without further puri®cation. H NMR
(CDCl3) d: 7.59 (d, Jˆ8.9 Hz, 1H, NH), 5.30 (app. t,
Jˆ9.8 Hz, 1H, H3), 4.95 (app. t, Jˆ9.8 Hz, 1H, H4), 4.77

C. Rosenbohm et al. / Tetrahedron 57 (2001) 6277±6287
6285
([M]1). Found C: 56.98 H: 9.62 N: 4.98; C26H52N2O6Si2
requires C: 57.27 H: 9.62 N: 5.14.
Jˆ9.3 Hz, 1H, H3), 3.54±3.37 (m, 3H, H7, H4), 3.21 (app.
t, Jˆ9.0 Hz, 1H, H5), 2.97±2.87 (m, 5H, H2, H10), 2.72±
2.68 (m 2H, H8), 2.65±2.51 (m, 6H, H6, H9); 13C NMR
(CD3OD) d: 102.0 (C1), 78.2 (C5), 75.1 (C3), 72.4 (C4),
67.8 (C7), 62.5 (C6), 58.1 (C2), 57.6 (C8), 51.1 (C9), 44.3
(C10). HRMS (ESI) m/z: 292.1893 ([MH]1, calculated
292.1872).
4.4. General puri®cation procedure for compounds 25±
34
Compounds 25±34 were puri®ed by cation exchange
chromatography on Amberlite CG-50 (NH41-form) using
0±2% conc. aqueous NH3 in H2O (v/v) as eluent, and subse-
quently converted into their hydrochloride salts by addition
of excess of 1.0 M aqueous HCl followed by lyophilization.
4.4.4. 2-(N-Methylpiperazino)ethyl 2-amino-2-deoxy-b-
d-glucopyranoside hydrochloride salt (28). Compound
17a (80 mg, 0.15 mmol) was dissolved in methanol
saturated with NH3 (5 ml) and the mixture was stirred for
18 h at rt. The solvent was removed under reduced pressure
and the puri®cation afforded compound 28 (42 mg, 66%) as
a white solid material. 1H NMR (CD3OD) d: 4.47 (d,
Jˆ8.2 Hz, 1H, H1), 3.63 (app. t, Jˆ9.1 Hz, 1H, H3),
3.56±3.39 (m, 3H, H7, H4), 3.24 (app. t, Jˆ9.0 Hz, 1H,
H5), 3.00±2.87 (m, 5H, H2, H10), 2.75±2.69 (m, 2H,
H8), 2.62±2.49 (m, 6H, H6, H9), 2.22 (s, 3H, H11); 13C
NMR (CD3OD) d: 101.8 (C1), 78.0 (C5), 75.4 (C3), 72.9
(C4), 67.6 (C7), 62.0 (C6), 58.0 (C2), 57.6 (C8), 53.3 (C10),
51.1 (C9), 45.8 (C11). HRMS (ESI) m/z: 306.2018 ([MH]1,
calculated 306.2029).
4.4.1. Allyl 2-amino-2,6-dideoxy-6-piperazino-b-d-
glucopyranoside hydrochloride salt (25). Compound 12
(78 mg, 0.13 mmol) was dissolved in TFA (1 ml) and the
mixture was stirred for 2 h at rt followed by evaporation
under reduced pressure and coevaporation with toluene to
afford a reddish gum which was dissolved in methanol
saturated with NH3 (5 ml) and stirred for 18 h at rt. The
solvent was removed under reduced pressure and puri®-
cation afforded compound 25 (28 mg, 51%) as a white
1
solid material. H NMR (D2O) d: 6.03±5.91 (m, 1H, H8),
5.35 (br. d, Jˆ17.2 Hz, 1H, H9), 5.28 (br. d, Jˆ10.3 Hz, 1H,
H9), 4.41 (d, Jˆ8.2 Hz, 1H, H1), 4.35 (dd, Jˆ13.6, 6.8 Hz,
1H, H7), 4.20 (dd, Jˆ12.5, 6.3 Hz, 1H, H7), 3.62 (app. t,
Jˆ9.3 Hz, 1H, H3), 3.35 (app. t, Jˆ9.0 Hz, 1H, H4), 3.20
(app. t, Jˆ9.1 Hz, 1H, H5), 2.95±2.84 (m, 5H, H2, H10)
2.65±2.51 (m, 6H, H6, H11); 13C NMR (D2O) d: 134.0 (C8),
119.4 (C9), 102.5 (C1), 76.2 (C5), 74.0 (C3), 72.5 (C7), 71.4
(C4), 59.4 (C6), 57.0 (C2), 53.5 (C10), 44.4 (C11). HRMS
(ESI) m/z: 288.1941 ([MH]1, calculated 288.1923).
4.4.5. 2-Piperazinoethyl 2,6-diamino-2,6-dideoxy-b-d-
glucopyranoside hydrochloride salt (29). Compound
18b (100 mg, 0.17 mmol) was dissolved in a 1:1 mixture
of abs. EtOH and dioxane (5 ml) and 20% Pd(OH)2/C
(20 mg) was added and the mixture was stirred under H2
for 18 h at rt. The catalyst was ®ltered off through celite
and the solution was concentrated. The residue was
dissolved in TFA (1 ml) and the mixture was stirred for
2 h at rt followed by evaporation under reduced pressure
and coevaporation with toluene to afford a reddish gum.
This gum was dissolved in methanol saturated with NH3
(5 ml) and the mixture was stirred for 18 h at rt. The solvent
was removed under reduced pressure and puri®cation
afforded compound 29 (54 mg, 73%) as a white solid
4.4.2. Allyl 2-amino-2,6-dideoxy-6-(N-methyl)pipera-
zino-b-d-glucopyranoside hydrochloride salt (26).
Compound 11 (50 mg, 0.10 mmol) was dissolved in metha-
nol saturated with NH3 (5 ml) and the mixture was stirred at
rt for 18 h. The solvent was removed under reduced pressure
and puri®cation afforded compound 26 (35 mg, 84%) as a
white solid material. 1H NMR (D2O) d: 6.05±5.91 (m, 1H,
H8), 5.35 (dd, Jˆ17.2, 1.5 Hz, 1H, H9), 5.28 (br. d, Jˆ10.3,
1.15 Hz, 1H, H9), 4.41 (d, Jˆ8.3 Hz, 1H, H1), 4.35 (dd,
Jˆ12.6, 6.0 Hz, 1H, H7), 4.20 (dd, Jˆ12.5, 6.3 Hz, 1H,
H7), 3.61 (app. t, Jˆ8.4 Hz, 1H, H3), 3.35 (dd, Jˆ9.4,
7.6 Hz, 1H, H4), 3.20 (app. t, Jˆ9.6 Hz, 1H, H5), 2.94 (d,
Jˆ13.8 Hz, 2H, H6) 2.77±2.51 (m, 9H, H2, H10, H11), 2.25
(s, 3H, H12); 13C NMR (D2O) d: 134.0 (C8), 119.5 (C9),
102.5 (C1), 76.2 (C5), 74.1 (C3), 72.5 (C7), 71.5 (C4), 58.7
(C6), 57.0 (C2), 53.9 (C10), 52.8 (C11), 44.9 (C12). MS
(ESI) m/z: 302 ([MH]1, calculated 302). To verify the
identity and purity of this product, a copy of the 13C NMR
spectrum was enclosed when submitting the revised
manuscript.
1
material. H NMR (D2O) d: 4.62 (d, Jˆ8.2 Hz, 1H, H1),
4.21±4.05 (m, 1H, H7), 3.83±3.70 (m, 1H, H7), 3.66 (app. t,
Jˆ9.3 Hz, 1H, H3), 3.60±3.37 (m, 6H, H4, H5, H6, H8),
3.30 (app. t, Jˆ8.2 Hz, 1H, H2), 2.96±2.70 (m, 8H, H9,
H10); 13C NMR (D2O) d: 100.8 (C1), 74.9 (C5), 76.3
(C3), 71.9 (C4), 67.1 (C7), 66.2 (C6), 56.9 (C2), 56.5
(C8), 49.6 (C9), 43.3 (C10). HRMS (ESI) m/z: 291.2001
([MH]1, calculated 291.2032).
4.4.6. 2-(N-Methylpiperazino)ethyl 2,6-diamino-2,6-
dideoxy-b-d-glucopyranoside hydrochloride salt (30).
Compound 18a (119 mg, 0.23 mmol) was dissolved in a
1:1 mixture of abs. EtOH and dioxane (5 ml), 20%
Pd(OH)2/C (20 mg) was added and the mixture was stirred
under H2 for 18 h at rt. The catalyst was ®ltered off through
celite and the solution was concentrated. The residue was
dissolved in methanol saturated with NH3 (5 ml) and the
resulting mixture was stirred for 18 h at rt. The solvent
was removed under reduced pressure and puri®cation
afforded compound 30 (49 mg, 47%) as a white solid
4.4.3. 2-Piperazinoethyl 2-amino-2-deoxy-b-d-gluco-
pyranoside hydrochloride salt (27). Compound 17b
(37 mg, 0.06 mmol) was dissolved in TFA (1 ml) and the
mixture was stirred for 2 h followed by evaporation under
reduced pressure and coevaporation with toluene to afford a
reddish gum which was dissolved in methanol saturated
with NH3 (5 ml) and stirred for 18 h at rt. The solvent was
removed under reduced pressure and puri®cation afforded
1
material. H NMR (D2O) d: 4.72 (d, Jˆ8.0 Hz, 1H, H1),
4.21±3.83 (m, 2H, H7), 3.64 (app. t, Jˆ8.3 Hz, 1H, H3),
3.69±3.32 (m, 6H, H4, H5, H6, H8), 3.25 (app. t, Jˆ7.9 Hz,
1H, H2), 2.91±2.71 (m, 8H, H9, H10), 2.29 (s, 3H, H11);
13C NMR (D2O) d: 100.5 (C1), 75.2 (C5), 74.8 (C3), 71.5
1
compound 27 (17 mg, 71%) as a white solid material. H
NMR (CD3OD) d: 4.50 (d, Jˆ8.4 Hz, 1H, H1), 3.73 (app. t,

6286
C. Rosenbohm et al. / Tetrahedron 57 (2001) 6277±6287
(C4), 67.2 (C7), 66.2 (C6), 56.4 (C2), 56.1 (C10), 56.0 (C8),
50.5 (C9), 43.4 (C11). HRMS (ESI) m/z: 305.2173 ([MH]1,
calculated 305.2189).
61.7 (C5), 48.8 (C6), 40.8 (C7). HRMS (ESI) m/z: 203.1367
([MH]1, calculated 203.1396).
4.5. Chemotherapeutical testing
4.4.7. 1,2-Dideoxy-2-(N-methylpiperazino)-d-ribofura-
nose hydrochloride salt (31). Compound 21 (34 mg,
0.07 mmol) was dissolved in THF (5 ml) and 1 M TBAF
in THF (0.15 ml) was added and the solution was stirred for
2 h at rt. The solvent was removed under reduced pressure
and puri®cation afforded compound 31 (19 mg, 90%) as a
The antibacterial and antifungal screening was carried out
according to the agar dilution test as described earlier.27a
The activity was determined against a gram-positive coccus
including Staphylococcus aureus ATCC 6538, a gram-
positive bacillus including Bacillus cereus ATCCC 14579,
gram-negative enteric bacilli including Escherichia coli
ATCCC 8739, Klebsiella pneumoniae ATCC 13883,
Pseudomonas aeruginosa ATCC 15442 and Salmonella
typhimurium ATCC 13311, the yeast Candida albicans
ATCC 10231 and the fungus Aspergillus niger ATCC
16404. The antiviral activity was determined according to
the end point titration technique (EPTT) as described
earlier.27b The following viruses were used: Herpes simplex
virus (type 1 (HSV-1), Coxsackie B2, virus (Cox B2),
Measles Edmondston A, poliomyelitis virus type 1, Semliki
forest virus L10, and vesicular stomatitis virus (VSV). The
antiviral activity against immunode®ciency virus type 1
(HIV-1) was evaluated in a microtiter assay as reported
before.27c
1
white solid material. H NMR (D2O) d: 4.40 (br. d, Jˆ
7.0 Hz, 1H, H4), 4.30±4.22 (m, 2H, H1), 4.02±3.98 (m,
1H, H2), 3.90±3.62 (m, 3H, H3, H5), 3.59±3.40 (m, 8H,
H6, H7), 2.29 (s, 3H, H8); 13C NMR (D2O) d: 84.2 (C2),
72.1 (C4), 71.5 (C3), 66.6 (C1), 60.9 (C5), 53.5 (C7), 48.2
(C6), 45.2 (C8). HRMS (ESI) m/z: 217.1578 ([MH]1, calcu-
lated 217.1552).
4.4.8. 1,2-Dideoxy-2-(N-methylpiperazino)-d-arabino-
furanose hydrochloride salt (32). Compound 22 (21 mg,
0.04 mmol) was dissolved in THF (5 ml) and 1 M TBAF in
THF (0.15 ml) was added and the solution was stirred for
2 h at rt. The solvent was removed under reduced pressure
and puri®cation afforded compound 32 (12 mg, 88%) as a
white solid material. 1H NMR (D2O) d: 4.70±4.59 (m, 1H,
H4), 4.50±4.42 (m, 1H, H1), 4.32±4.22 (m, 1H, H1), 4.05±
3.98 (m, 2H, H2, H3), 3.86±3.72 (m, 2H, H5), 3.57±3.37
(m, 8H, H6, H7), 2.25 (s, 3H, H8); 13C NMR (D2O) d: 88.0
(C2), 70.0 (C4), 67.0 (C3), 66.1 (C1), 61.9 (C5), 53.1 (C7),
47.9 (C6), 45.1 (C8). HRMS (ESI) m/z: 217.1567 ([MH]1,
calculated 217.1552).
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1
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