Design, modeling and synthesis of functionalized paromamine analogs

Article abstract of DOI:10.1016/S0040-4020(01)00194-6

Based on the published NMR structure of the antibiotic paromomycin complexed with the A-site of Escherichia coli 16S ribosomal RNA, a set of C-5 functionalized analogs of paromamine was designed and synthesized, incorporating cyclic and acyclic appendages and terminating with one or more ammonium groups.

Full text of DOI:10.1016/S0040-4020(01)00194-6

TETRAHEDRON
Pergamon
Tetrahedron 57 52001) 3255±3265
Design, modeling and synthesis of functionalized
paromamine analogs
Stephen Hanessian,p Martin Tremblay, Alexander Kornienko and Nicolas Moitessier
 Â
Department of Chemistry, Universite de Montreal, P.O. Box 6128, Station Centre-ville, Montreal, Quebec H3C 3J7, Canada
Received 28 November 2000;accepted 12 February 2001
AbstractÐBased on the published NMR structure of the antibiotic paromomycin complexed with the A-site of Escherichia coli 16S
ribosomal RNA, a set of C-5 functionalized analogs of paromamine was designed and synthesized, incorporating cyclic and acyclic
appendages and terminating with one or more ammonium groups. q 2001 Elsevier Science Ltd. All rights reserved.
1. Introduction
structural requirements for antibacterial activity.13 We now
report on the synthesis of a set of branched paromamines,
the pseudo-disaccharide corresponding to paromomycin but
lacking the d-ribose and the 2,6-deoxy-2,6-diamino-l-idose
units.14
Aminoglycoside antibiotics are a group of clinically impor-
tant antibacterial drugs which exert their function through
speci®c binding to prokaryotic ribosomal RNA, thus affect-
ing protein biosynthesis.1 However, their widespread use
over the last decades has been signi®cantly compromised
by oto- and nephrotoxicity,2 and the rapid emergence of
bacterial resistance.3 A major breakthrough in this area of
research was the discovery that the pseudo-trisaccharide
butyrosin,4 in which N-1 of the deoxystreptamine moiety
was acylated with 4-amino-25S)-hydroxyaminobutyric
acid, was less susceptible to inactivating enzymes, while
maintaining potency. Armed with this information the
chemical modi®cation of the existing aminoglycosides has
resulted in the development of clinically useful antibiotics
such as amikacin.5
2. Library design
The A-site of the prokaryotic 16S ribosomal RNA has been
localized as the binding site for the group of 4,5-disubsti-
tuted deoxystreptamines, including the antibiotics neomycin
and paromomycin 5Fig. 1).8
Moreover, the solution structure of the A-site of E. coli 16S
ribosomal RNA complexed with paromomycin has been
determined by NMR spectroscopy.15 According to this
elegant analysis, paromomycin binds in the major groove
of the A-site within the internal loop 5Fig. 2a). Rings I and II
of paromomycin ®t into the pocket created by an asym-
metrical bulge, and make speci®c contacts with the nucleic
acid bases and phosphate residues. Rings III and IV, on the
other hand, extend along the major groove, and their contri-
bution to the binding event is less important as no speci®c
contacts with RNA are observed. This is also corroborated
by the observation that ribostamycin, a pseudo-trisaccharide
related to neomycin but lacking ring IV, and neamine itself
The chemistry of aminoglycoside antibiotics remained in a
state of hiatus for a number of years, in part due to the
emergence of other classes of potent antibacterial agents
such as carbapenems6 and quinolones.7 In spite of the poly-
functional nature of aminoglycosides, a great deal of
chemical know-how has been developed over the years in
order to allow selective functionalizations. The recent
achievements in understanding the interactions of amino-
glycosides with RNA8 have rekindled interest in the design
of mimetics and analogs that may simulate the biological
activity of these compounds.9±11 Efforts have been made to
design analogs to overcome bacterial resistance to amino-
glycosides.12
Past experience in our laboratory has led to the synthesis of
a number of aminoglycoside analogs to probe functional and
Keywords: aminoglycoside;paromomycin;RNA;library;modeling.
Corresponding author. Tel.: 1514-343-6738;fax: 1514-343-5728;
e-mail: hanessia@ere.umontreal.ca
p
Figure 1.
0040±4020/01/$ - see front matter q 2001 Elsevier Science Ltd. All rights reserved.
PII: S0040-4020501)00194-6

3256
S. Hanessian et al. / Tetrahedron 57 02001) 3255±3265
Figure 2. 5a) NMR determined structure of paromomycin±RNA complex according to Puglisi.15 5b) GRID mapping of the groove;energetically favored
spaces for ammonium groups 5blue) and for hydroxyl groups 5red).
form similar complexes with the A-site RNA.8 Modeling
studies of RNA±aminoglycoside complexes have been
reported by Cedergren16and Westhof.17 Very recently, the
crystal structure of the 30S subunit of ribosomal RNA from
Thermus thermophilus complexed with paromomycin
has been described, providing interesting insights into the
binding of each residue.18
We chose to synthesize a series of C-5 substituted paroma-
mines which carried cyclic and acyclic appendages
containing amino groups 5Fig. 3a, b) which could make
electrostatic contacts with the phosphate groups of the
A-site nucleic acid backbone. To this end, we considered
morpholines as conformationally constrained mimics of the
ribosyl ring, and linear primary amines branched at C-5 as
acyclic equivalents. Morpholino analogs of dibekacin have
been reported by Tsuchiya and coworkers21.
When we used the GRID program19 to map the binding site
of RNA, using the structures already established by Puglisi
and coworkers,15 we found that ammonium groups would
occupy energetically favorable sites on the region normally
occupied by ring IV of paromomycin, and surrounded by
numerous phosphate groups. We reasoned that by replacing
rings III and IV of paromomycin with appendages carrying
terminal ammonium groups, we could perhaps mimic their
The proposed interactions of a 5-5guanidinoethylmorpho-
lino)glycoside, and a 5-5guanidinoethylamino)ethoxy ether
of paromamine with the A-site nucleic acid backbone based
on the original Puglisi model15 are shown in Fig. 4.
Á
functional and spacial requirements vis-a-vis the A-site
3. Results and discussion
RNA. This might also lead to simpler structures possibly
possessing promising antibacterial activities. Simple
aminols that bind RNA as surrogates for aminoglycoside
antibiotics have been reported by Tok and Rando.20
Ring IV of paromomycin was removed via a sequence of
reactions involving a b-elimination as a key step following
our published work of some years ago 5Scheme 1).22 The
periodic acid cleavage of the diol in 3 gave dialdehyde 4,
which was not puri®ed due to its instability, but directly
subjected to a reductive coupling with a variety of primary
amines 5Scheme 2). The yields of cyclic amines were some-
what modest due to the formation of open chain diamines
and the reactions required carefully selected conditions. By
adjusting the pH to 6, employing high dilution conditions
and slow addition of an amine to a solution of 4 in MeOH/
DMF we were able to obtain the desired morpholines 5a±h.
The monoprotected amines were synthesized by conven-
tional methods23 and the protected guanidinoethylamine
was prepared using Goodman's methodology.24 The b-52-
aminoethyl)glucoside precursor to 5f was synthesized by
using a glycosylation method developed in our group.25a
Figure 3.

S. Hanessian et al. / Tetrahedron 57 02001) 3255±3265
3257
Figure 4. Proposed docked structures for two representative paromamine derivatives, as tetra tri¯uoroacetate salts.
Thus, compound 6 was benzoylated, and the product 7 was
treated with N-Cbz ethanolamine in the presence of
HBF4´Et2O to afford 8 as a single isomer in a good yield
5Scheme 3).25b The benzoates were removed with cat.
NaOMe in MeOH to give 9 and the Cbz group was hydro-
genolyzed to afford 10, which was used for the reductive
amination with 4.
resulting pseudo-disaccharide were protected as benzyl
carbamates to afford 11, following an earlier report 5Scheme
5).26 We then took advantage of our previous observation
that the C-5 hydroxyl was resistant towards acetylation in a
series of similarly protected paromamines.13b Gratifyingly,
acetylation of 11 led to the same high level of regioselec-
tivity, affording the tetraacetate 12 in acceptable yield. The
regiochemistry was con®rmed by COSY analysis after
hydrogenolysis. O-Allylation14a of 12 afforded 13 without
ester migration as ascertained by COSY analysis of a
derivative. Ozonolysis of 13 gave 14, which upon reductive
coupling with a variety of N-protected primary alkylamines,
secondary amines, and alkylguanidines provided fully
protected disaccharides 17a±e in good yields 5Scheme 6).
Compound 13 was also subjected to ozonolysis followed by
reduction of the resulting aldehyde with sodium boro-
hydride 5Scheme 5). The primary alcohol was mesylated
and replaced by azide to give 15 in good overall yield.
Deprotection of 5a±h involved the removal of the benzyl-
idene group with hot aqueous acetic acid followed by hydro-
genolysis over 20% palladium hydroxide on carbon to
afford the extended paromamine analogs 1a±h representing
a cross-section of appendages, some of which were guided
by our modeling studies 5Scheme 4).
For the synthesis of C-5 alkylamino ether analogs of
paromamine, rings III and IV of paromomycin were
chemically removed, and the three amino groups of the
Ph
O
O
O
HO
Cbz-HN
NH-Cbz
Ph
O
O
O
O
NH-Cbz
O
HO
HO
Cbz-HN
OH
O
NH-Cbz
Steps22
O
Paromomycin
NH-Cbz
O
HO
OH
O
OH
O
Cbz-HN
O
NH-Cbz
OH
OHC
OHC
OH
H
3
..
Et3N
Scheme 1.

3258
S. Hanessian et al. / Tetrahedron 57 02001) 3255±3265
Ph
O
Ph
O
O
O
O
O
HO
Cbz-HN
HO
Cbz-HN
NH-Cbz
NH-Cbz
H5IO6
THF/DMF
NaBH3CN
O
O
3
NH-Cbz
NH-Cbz
HO
O
MeOH/DMF
AcOH (pH 6)
HO
O
OH
O
OH
O
CHO CHO
R'-NH2
N
R'
4
5a-h
R'
R'
Yield
Yield
Product
Product
26%
20%
5a
OH
O
H3C
5f
HO
HO
O
42%
OH
5b
5c
OH
HO
HO
O
37%
NH-Cbz
Cbz-HN
5g
O
25%
NH-Cbz
O
OH
30%
41%
Cbz-HN
Cbz-HN
5d
5e
N-Boc
5h
47%
Boc-HN
N
H
Scheme 2.
Finally, the acetates were removed with cat. NaOMe in
MeOH and the azide was reduced with PPh3/H2O to give
16 that was used to provide 5g 5Scheme 2).
C-5 substituted paromamine derivatives representing a small
library of paromomycin mimetics based on computer-aided
design. In one series, the C-5 appendage consisted of a
morpholino glycoside as a pseudo-sugar, in which the nitro-
gen atom was functionalized with a variety of chains deployed
with hydrophobic or basic end-groups such as compounds
1a±e, 1h as well as dimeric aminoglycosides exempli®ed
by 1f and 1g 5Scheme 4). In another series, the C-5 appendage
consisted of v-amino or v-guanidino alkyl ethers varying in
Deprotection of compounds 17a±e with catalytic NaOMe in
MeOH followed by hydrogenolysis led to the analogs 2a±e
5Scheme 7).
In conclusion, we have reported the preparation of a series of
steps25a
OH
OMe
OAc
O
OBz
O
OMe
BzCl
O
HO
HO
AcO
AcO
O
BzO
BzO
OAc
O
Pyridine
77%
OH
OAc
OBz
N
N
β-D-glucose pentaacetate
6
7
NH-Cbz
HO
HBF4 Et2O
CH2Cl2
75%
OH
O
Pd/C 10%
OH
OBz
O
HO
O
O
H2
NaOMe/MeOH
90%
HO
HO
O
BzO
BzO
HO
NH2
O
NH-Cbz
NH-Cbz
AcOH
quantitative
OH
OH
OBz
8
AcOH salt
10
9
Scheme 3.

S. Hanessian et al. / Tetrahedron 57 02001) 3255±3265
3259
OH
O
HO
HO
1) AcOH (80% in H2O)
60oC, 2h
NH2
H2N
O
5
NH2
HO
O
2) Pd(OH)2, H2
AcOH 80%
OH
O
xn AcOH
N
R
1a-h
Product
Product
R
O
Starting
Material
R
Yield
Starting
Material
Yield
quant.
5a
1a
H
OH
O
HO
5f
1f
quant.
HO
OH
quant.
quant.
5b
5c
1b
1c
OH
HO
HO
O
quant.
NH2
H2N
5g
1g
O
NH2
O
OH
quant.
quant.
5d
5e
1d
1e
H2N
NH
quant.a
5h
1h
H2N
N
H
H2N
Scheme 4. a Deprotection conditions involved: 51) TFA/H2O 510:1) 2 h, 52) H2Pd5OH)2 in AcOH 580% in H2O).
length such as compounds 2a±c. This series also included
an N-piperazinoethyl ether analog 2d 5Scheme 7).
Low- and high-resolution mass spectra were recorded on
VG Micromass, AEI-MS 902 or Kratos MS-50 spectro-
meters using fast atom bombardement 5FAB) or electro-
spray techniques. Optical rotations were recorded on a
Perkin±Elmer 241 polarimeter in a 1 dm cell at ambient
temperature. Analytical thin-layer chromatography was
performed on Merck 60F254 pre-coated silica gel plates.
Visualization was performed by ultraviolet light and/or by
staining with ceric ammonium molybdate or ninhydrine.
Flash column chromatography was performed using 540±
60 mm) silica gel at increased pressure.
Disappointingly, none of the above analogs exhibited any
antibacterial activity when tested against a panel of resistant
and sensitive strains of Pseudomonas aeruginosa,
Staphylococcus aureus, Escherichia coli, and Enterococcus
faecalis at 50 mg/mL. Surprisingly, very closely related
analogs based on the neamine core structure 5Fig. 1) have
been reported to exhibit signi®cant antibacterial activity
against E. coli.10b,14a Clearly, there is much to be learned
about the functional and spacial requirements for effective
ribosomal binding, as opposed to modeling based on an
RNA substructure, in the design of such truncated amino-
glycoside mimetics. The binding of our analogs to various
RNAs, though of academic interest now, will be reported in
due course.
4.2. General procedure for reductive amination ,5a±h)
To a suspension of 3 50.21 mmol) in THF 55 mL) at 08C was
added DMF 50.5 mL) until complete dissolution. After addi-
tion of periodic acid 50.32 mmol) and stirring for a few
minutes, a white precipitate appeared. The reaction mixture
was stirred overnight at 58C then evaporated under vacuum
and the resulting white solid was partitioned between water
and EtOAc. The aqueous layer was extracted with EtOAc,
and the combined organic extracts were dried over Na2SO4.
The solvent was evaporated to give a white solid. The crude
dialdehyde was suspended in MeOH 512 mL) and DMF
52 mL) was added until complete dissolution, followed by
NaBH3CN 555 mg, 0.87 mmol). A solution containing the
appropriate amine 50.17 mmol) and AcOH 50.90 mmol) in
MeOH 52 mL) was added to the reaction mixture over a
period of 1 h. After stirring at room temperature for 1 h, a
few drops of Et3N were added and the solvents were
4. Experimental
4.1. General information
Solvents were distilled under positive pressure of dry nitro-
gen before use and dried by standard methods;THF and
ether, from Na/benzophenone;and CH Cl2, from CaCl2.
2
All commercially available reagents were used without
further puri®cation. All reactions were performed under
nitrogen atmosphere. NMR 51H, 13C) spectra were recorded
on AMX-300, ARX-400 and DMX-600 spectrometers.

3260
S. Hanessian et al. / Tetrahedron 57 02001) 3255±3265
OAc
O
OH
AcO
AcO
HO
HO
O
Ac2O
DMF, Pyridine
46%
Steps26
NH-Cbz
NH-Cbz
Paromomycin
Cbz-HN
Cbz-HN
O
HO
O
NH-Cbz
Br
NH-Cbz
HO
11
OAc
OH
12
1)
2)
Bu4NI, DMF
LiHMDS
43%
OAc
OAc
AcO
AcO
O
AcO
AcO
O
1) O3, CH2Cl2, -78oC
NH-Cbz
NH-Cbz
Cbz-HN
Cbz-HN
O
O
2) PPh3
84%
NH-Cbz
OAc
NH-Cbz
OAc
O
O
13
O
14
1) O3, CH2Cl2, -78oC
2) NaBH4
3) MsCl, Collidine, CH2Cl2
4) NaN3, DMF, ∆
60%
OAc
O
OH
O
AcO
AcO
HO
HO
NH-Cbz
1) cat. NaOMe, MeOH
Cbz-HN
NH-Cbz
Cbz-HN
O
O
NH-Cbz
OAc
O
NH-Cbz
2) PPh3, H2O, ∆, then AcOH
O
OH
quant.
N3
15
AcOH salt
H2N
16
Scheme 5.
removed under vacuum. Na2CO3 5satd., 30 mL) was added,
the suspension was extracted with EtOAc and the combined
organic extracts were dried over Na2SO4. The mixture was
concentrated under vacuum and the residue was puri®ed by
¯ash chromatography 5CH2Cl2/MeOH, 9:1) to give 5a±h as
white solids.
NMR 575 MHz, CD3OD) d 159.0, 158.6, 158.1, 139.2,
138.9, 138.4, 138.3, 138.2, 131.1, 130.1, 129.9, 129.8,
129.5, 129.4, 129.3, 129.0, 128.9, 128.8, 128.6, 127.6,
127.4, 103.1, 102.9, 102.1, 85.2, 84.7, 83.5, 76.9, 75.4,
69.9, 67.7, 67.5, 65.5, 63.6, 62.8, 58.9, 56.3, 53.7, 52.7,
19.1;FAB for C 56H64N4O15 calcd 5M1H1) 1034.4, found
1034.5.
4.2.1. Compound 5a. 20%; 1H NMR 5300 MHz, CDCl3) d
7.44±7.07 5m, 24H), 5.46 5s, 1H), 5.18±4.98 5m, 8H), 4.79
5s, 1H), 4.25 5s, 1H), 3.98±3.32 5m, 18H), 2.30 5s, 3H); 13C
4.2.2. Compound 5b. 20%; 1H NMR 5300 MHz, CDCl3) d
7.49±6.90 5m, 25H), 5.54 5s, 1H), 5.13±4.89 5m, 8H), 4.21
OAc
AcO
O
AcO
NaBH3CN
NH-Cbz
Cbz-HN
14
O
MeOH, AcOH
NH-Cbz
OAc
O
R''R'NH
17a-e
R'
N
R''
R'', R'
Yield
Yield
94%
Product
Product
R'', (R'=H)
66%
73%
Cbz-HN
17a
17d
17e
Cbz-N
Cbz-HN
17b
17c
NBoc
38%
Cbz-HN
75%
BocHN
N
H
Scheme 6.

S. Hanessian et al. / Tetrahedron 57 02001) 3255±3265
3261
OH
O
HO
HO
1)
2)
cat. NaOMe/MeOH
NH2
H2N
17
O
O
NH2
Pd/C 10%
H2
OH
H2O/dioxane/AcOH
R'
N
R
2a-e
xn AcOH
R, R'
Product
Product
Starting
Material
Yield
Starting
Material
Yield
R, (R'=H)
17a
2a
quant.
H2N
quant.
17d
17e
2d
HN
17b
17c
2b
2c
quant.
quant.a
H2N
quant.
2e
H2N
NH
H2N
N
H
Scheme 7. a Deprotection conditions involved: 51) TFA/H2O 510:1) 1 h, 52) H2, Pd/C in H2O/dioxane/AcOH.
5m, 1H), 4.05±3.10 5m, 18H), 2.90 5m, 1H), 2.70 5m, 1H),
2.35 5m, 1H), 2.20±1.90 5m, 2H), 1.55 5m, 1H); 13C NMR
575 MHz, CD3OD) d 158.9, 158.7, 158.0, 139.2, 138.3,
138.2, 137.9, 129.9, 129.8, 129.7, 129.6, 129.5, 129.3,
129.1, 129.0, 128.9, 128.5, 127.7, 127.6, 127.4, 103.1,
102.9, 101.5, 85.6, 84.6, 83.5, 83.4, 77.1, 70.1, 67.9, 67.8,
67.5, 67.4, 65.5, 63.4, 60.4, 58.9, 53.8, 52.7, 34.8, 32.3;
FAB for C56H64N4O15 calcd 5M1H1) 1034.1, found 1034.4.
129.5, 129.3, 128.9, 128.9, 127.6, 103.1, 102.9, 102.7,
85.2, 84.8, 83.5, 77.1, 76.1, 70.1, 69.9, 67.9, 67.7, 67.5,
67.4, 65.5, 63.9, 58.9, 57.1, 56.4, 54.2, 52.8, 40.0, 31.2,
27.6;FAB for C 59H69N5O17 calcd 5M1H1) 1121.2, found
1121.6.
4.2.6. Compound 5f. 42%; 1H NMR 5300 MHz, CD3OD) d
7.50±7.25 5m, 20H), 5.54 5s, 1H), 5.13±4.90 5m, 9H), 4.30±
4.15 5m, 2H), 3.96 5t, Jˆ9.3 Hz, 1H), 3.92±3.21 5m, 24H),
3.17 5t, Jˆ7.8 Hz, 1H), 3.00 5m, 1H), 2.65 5m, 1H), 2.30 5m,
1H), 2.15±1.85 5m, 3H), 1.65±1.50 5m, 1H), 1.48±1.30 5m,
2H); 13C NMR 5100 MHz, CD3OD) d 159.1, 159.0, 158.6,
158.1, 139.2, 138.3, 138.1, 138.0, 129.9, 129.7, 129.5,
129.3, 129.0, 128.9, 128.9, 127.6, 104.4, 103.1, 102.8,
102.3, 85.1, 84.7, 83.51, 77.9, 77.7, 76.9, 75.7, 75.0, 73.2,
72.0, 71.6, 70.0, 69.9, 67.9, 67.5, 66.4, 65.4, 63.8, 62.7,
62.2, 58.9, 58.8, 58.3, 57.5, 53.7, 52.7, 35.7, 32.8, 20.3,
14.2;FAB for C 56H70N4O21 calcd 5M1Na1) 1157.2,
found 1157.4.
4.2.3. Compound 5c. 25%; 1H NMR 5300 MHz, CDCl3) d
7.55±7.10 5m, 25H), 5.53 5s, 1H), 5.15±4.80 5m, 8H), 4.25
5m, 1H), 4.15±3.35 5m, 16H), 2.90 5m, 1H), 2.52 5t, Jˆ7 Hz,
2H), 2.10±1.50 5m, 5H), 1.40 5m, 1H); 13C NMR 575 MHz,
CD3OD) d 159.4, 158.6, 158.0, 143.2, 139.2, 138.3, 138.1,
130.5, 130.4, 130.3, 130.2, 129.9, 129.8, 129.7, 129.6,
129.3, 129.2, 128.8, 128.6, 128.5, 128.3, 128.2, 127.9,
127.3, 127.2, 103.2, 102.9, 102.7, 85.0, 76.2, 75.9, 70.0,
67.8, 67.7, 67.5, 63.8, 58.5, 52.9, 52.7, 52.6, 34.4, 29.0;
FAB for C57H66N4O15 calcd 5M1H1) 1048.2, found
1048.5.
4.2.7. Compound 5g. 39%; 1H NMR 5600 MHz, DMSO-d6)
d 7.50±6.90 5m, 35H), 6.70±6.75 5broad s, 1H), 5.57 5s,
1H), 5.25±4.75 5m, 15H), 4.10±4.32 5broad m, 3H), 3.85±
3.20 5m, 40H), 2.93±2.90 5m, 1H), 2.75±2.69 5m, 1H),
2.20±2.17 5m, 1H), 1.85±1.60 5m, 4H);FAB for
C94H107N7O32 calcd 5M1Na1) 1680.7, found 1680.8.
4.2.4. Compound 5d. 30%; 1H NMR 5400 MHz, CD3OD) d
7.50±7.20 5m, 25H), 5.54 5s, 1H), 5.14±4.80 5m, 10H), 4.25
5m, 1H), 4.10±3.35 5m, 16H), 3.10 5m, 1H), 2.92 5m, 1H),
2.55 5m, 1H), 2.15±1.70 5m, 4H), 1.42 5m, 1H); 13C NMR
575 MHz, CD3OD) d 159.1, 158.7, 158.6, 158.1, 139.2,
138.3, 138.2, 137.9, 130.2, 130.0, 129.9, 129.8, 129.4,
129.2, 128.7, 128.6, 127.9, 127.8, 127.3, 103.3, 102.9,
102.8, 84.9, 84.9, 83.7, 83.4, 76.3, 75.9, 70.0, 69.9, 69.9,
69.9, 69.8, 68.2, 67.9, 67.7, 67.6, 67.5, 67.2, 63.8;FAB for
C58H67N5O17 calcd 5M1H1) 1107.2, found 1107.8.
1
4.2.8. Compound 5h. 47%; H NMR 5400 MHz, CDCl3)
d 7.53±7.05 5m, 20H), 5.54 5s, 1H), 5.20±4.90 5m, 9H),
4.30±4.20 5m, 1H), 4.17±3.86 5m, 2H), 3.84±3.72 5m,
1H), 3.70±3.20 5m, 16H), 2.95±2.88 5m, 1H), 2.61±2.50
5m, 1H), 2.15±1.73 5m, 4H), 1.51 5s, 9H), 1.48 5s, 9H);
13C NMR 5100 MHz, CD3OD) d 159.1, 158.6, 158.1,
157.5, 153.9, 139.2, 138.3, 138.2, 137.9, 129.9, 129.7,
129.5, 129.0, 128.9, 128.8, 127.6, 103.1, 102.7, 84.9, 84.4,
83.5, 80.3, 77.0, 76.3, 69.9, 68.0, 67.4, 65.4, 63.9, 58.9,
56.8, 56.5, 53.9, 52.6, 38.5, 35.7, 28.6, 28.3;FAB for
C61H79N7O19 calcd 5M1H1) 1214.6, found 1214.7.
4.2.5. Compound 5e. 41%; 1H NMR 5300 MHz, CD3OD) d
7.50±7.12 5m, 25H), 5.53 5s, 1H), 5.13±4.85 5m, 10H), 4.23
5m, 1H), 4.08±3.35 5m, 16H), 3.04 5t, Jˆ6.5 Hz, 2H), 2.93
5m, 1H), 2.50 5m, 1H), 2.10±1.65 5m, 5H), 1.60±1.30 5m,
2H); 13C NMR 575 MHz, CD3OD) d 159.1, 158.7, 158.1,
158.0, 139.2, 138.4, 138.3, 138.2, 138.1, 129.9, 129.6,

3262
S. Hanessian et al. / Tetrahedron 57 02001) 3255±3265
4.3. General procedure for deprotection ,1a±g)
13C NMR 5100 MHz, D2O) d 182.2, 103.1, 101.1, 98.3,
83.4, 81.8, 76.8, 76.4, 75.4, 74.5, 73.9, 70.4, 70.2, 66.7,
62.5, 64.5, 61.2, 57.2, 56.6, 55.1, 52.9, 50.6, 50.4, 30.7,
24.0;[ a]Dˆ110.0 5c 0.90, H2O).
A solution of the starting material 50.026 mmol) in AcOH
580% in water, 2 mL) was heated at 608C for 3 h and the
solvents were removed under vacuum. To the resulting
residue in AcOH 580% in water, 2 mL) was added 20%
palladium hydroxide on carbon and stirred under 1 atm of
H2 at rt for 1 h. The mixture was ®ltered through a Celite
pad, concentrated under vacuum, and the residue was
dissolved in water and lyophilized to afford 1a±g as ¯uffy
white solids.
1
4.3.7. Compound 1g. Quantitative; H NMR 5400 MHz,
D2O) d 5.62 5d, Jˆ3.8 Hz, 1H), 5.49 5d, Jˆ3.4 Hz, 1H),
5.11 5d, Jˆ7.5 Hz, 1H), 4.10±3.20 5m, 38H), 3.00±2.90
5m, 1H), 2.80±2.70 5m, 2H), 2.52±2.38 5m, 2H), 2.20±
2.09 5m, 2H), 1.93 5s, 21H), 1.85±1.70 5m, 2H); 13C NMR
5150 MHz, D2O) d 181.6, 100.7, 97.9, 96.0, 83.2, 82.3, 81.8,
81.3, 79.0, 76.4, 74.9, 74.3, 73.3, 72.7, 70.4, 69.8, 69.6,
67.4, 62.0, 60.8, 60.7, 56.3, 54.6, 53.2, 50.3, 50.0, 49.9,
49.5, 30.6, 29.8, 23.5;[ a]Dˆ120.7 5c 0.90, H2O).
1
4.3.1. Compound 1a. Quantitative; H NMR 5400 MHz,
D2O) d 5.50 5d, Jˆ3.6 Hz, 1H), 5.31 5d, Jˆ7.3 Hz, 1H),
4.05±3.22 5m, 18H), 2.93 5t, Jˆ12.5 Hz, 1H), 2.84 5t, Jˆ
11.0 Hz, 1H), 2.40 5m, 1H), 1.88 5s, 12H), 1.70 5dd, Jˆ8.4,
12.8 Hz, 1H); 13C NMR 575 MHz, D2O) d 179.5, 96.9, 95.4,
79.6, 79.4, 71.9, 71.7, 71.0, 67.7, 67.5, 59.0, 58.5, 52.4,
47.8, 47.6, 43.4, 40.9, 27.8, 21.4, 21.3;[ a]Dˆ130.2 5c
1.10, H2O).
4.3.8. Compound 1h. To a solution of the starting material
50.026 mmol) in TFA 52 mL) was added H2O 55 drops),
stirred for 2 h and the solvent was removed under vacuum.
To the resulting residue in AcOH 580% in water, 2 mL) was
added 20% palladium hydroxide on carbon at rt for 1 h.
Then, the mixture was ®ltered through a Celite pad, concen-
trated under vacuum, diluted with water and lyophilized to
1
4.3.2. Compound 1b. Quantitative; H NMR 5400 MHz,
1
afford 1h 5quantitative) as a ¯uffy white solid; H NMR
D2O) d 7.40±7.25 5m, 5H), 5.49 5d, Jˆ3.7 Hz, 1H), 5.16
5d, Jˆ7.8 Hz, 1H), 4.06±3.29 5m, 22H), 3.06 5d, Jˆ11.6 Hz,
1H), 2.43 5m, 1H), 2.29 5t, Jˆ11.3 Hz, 1H), 2.20 5t, Jˆ
11.6 Hz, 1H), 1.91 5s, 12H), 1.72 5dd, Jˆ7.4, 11.9 Hz,
1H); 13C NMR 575 MHz, D2O) d 179.0, 137.5, 127.0,
126.9, 124.8, 98.5, 95.7, 95.7, 80.3, 79.2, 72.6, 72.0, 71.1,
67.7, 67.6, 59.8, 58.6, 57.1, 53.4, 52.4, 50.3, 47.9, 47.7,
29.6, 27.8;[ a]Dˆ128.5 5c 1.00, H2O).
5400 MHz, D2O) d 5.56 5d, Jˆ3.8 Hz, 1H), 5.35 5d, Jˆ
9.1 Hz, 1H), 4.12±3.20 5m, 26H), 2.88 5t, Jˆ11.8 Hz,
1H), 2.79 5t, Jˆ10.8 Hz, 1H), 2.55±2.43 5m, 1H), 1.85
5dd, Jˆ12.7 Hz, 1H); 13C NMR 5100 MHz, D2O) d 163.9,
163.6, 157.8, 121.5, 118.6, 115.7, 112.5, 99.2, 97.7, 82.2,
80.3, 74.9, 73.3, 73.1, 70.1, 69.9, 61.5, 61.2, 56.2, 54.8,
54.3, 52.1, 50.1, 36.9, 28.9;[ a]Dˆ126.8 5c 1.00, H2O).
1
4.3.9. Compound 7. To a solution of 6 5200 mg,
0.70 mmol) in anhydrous pyridine 57 mL) was added
benzoyl chloride 50.39 mL, 3.34 mmol). The mixture was
stirred at rt until reaction was complete, after which a few
drops of MeOH were added. After stirring for a further
15 min, the solution was concentrated and the residue was
dissolved in EtOAc and washed with water, brine and dried
over MgSO4. The solvent was removed under vacuum, and
the resulting white solid was puri®ed by ¯ash chroma-
tography 5EtOAc/hexanes, 1:1) to give 7 5377 mg, 77%)
4.3.3. Compound 1c. Quantitative; H NMR 5300 MHz,
D2O) d 7.38±7.25 5m, 5H), 5.45 5d, Jˆ3.4 Hz, 1H), 5.17
5d, Jˆ9.4 Hz, 1H), 4.00±3.28 5m, 16H), 3.09 5d, Jˆ12.2 Hz,
1H), 2.80±2.58 5m, 4H), 2.50±2.20 5m, 3H), 1.88 5s, 12H),
1.72 5dd, Jˆ6.7, 12.5 Hz, 1H); 13C NMR 575 MHz, D2O) d
179.5, 139.9, 126.9, 126.7, 124.4, 98.1, 95.6, 80.2, 79.3,
72.3, 71.9, 71.1, 67.7, 67.6, 59.6, 58.5, 55.1, 53.0, 52.4,
50.1, 47.8, 47.7, 30.7, 27.8, 24.6;[ a]Dˆ127.9 5c 1.20, H2O).
1
4.3.4. Compound 1d. Quantitative; H NMR 5300 MHz,
1
as a white solid; H NMR 5300 MHz, CDCl3) d 8.00±7.87
D2O) d 5.41 5d, Jˆ3.8 Hz, 1H), 5.05 5d, Jˆ7.0 Hz, 1H),
4.90±3.08 5m, 20H), 2.80 5d, Jˆ10.9 Hz, 1H), 2.70 5t, Jˆ
6.2 Hz, 2H), 2.33 5m, 1H), 2.20 5dd, Jˆ7.2, 10.3 Hz, 2H),
1.87 5s, 15H), 1.64 5dd, Jˆ8.2, 12.4 Hz, 1H); 13C NMR
575 MHz, D2O) d 179.6, 98.8, 95.8, 81.1, 79.1, 73.1, 71.9,
71.4, 67.9, 67.6, 59.9, 58.5, 53.9, 52.5, 51.6, 50.4, 47.9,
47.7, 34.0, 28.3, 21.4;[ a]Dˆ133.1 5c 1.00, H2O).
5m, 7H), 7.70 5dd, Jˆ1.5, 5.7 Hz, 1H), 7.60±7.25 5m, 13H),
7.04 5dd, Jˆ1.5, 8.6 Hz, 1H), 6.90 5dd, Jˆ4.9, 10.3 Hz, 1H),
6.63 5d, Jˆ7.6 Hz, 1H), 6.03 5t, Jˆ9.1 Hz, 1H), 5.91 5t, Jˆ
7.6 Hz, 1H), 5.79 5t, Jˆ9.3 Hz, 1H), 4.64 5dd, Jˆ3.2,
8.8 Hz, 1H), 4.60±4.35 5m, 2H), 3.74 5s, 3H); 13C NMR
5100 MHz, CD3OD) d 165.9, 165.6, 165.0, 164.9, 151.5,
144.2, 136.6, 133.3, 133.1, 132.9, 132.8, 129.9, 129.7,
129.6, 129.5, 129.1, 128.7, 128.7, 128.3, 128.2, 128.1,
119.2, 118.9, 93.8, 72.9, 72.6, 71.2, 69.3, 62.9, 55.7;
[a]Dˆ134,7 5c 2.3, CHCl3);HRMS for C 40H33NO11 calcd
5M1H1) 704.21320, found 704.21440.
1
4.3.5. Compound 1e. Quantitative; H NMR 5300 MHz,
D2O) d 5.45 5d, Jˆ3.2 Hz, 1H), 5.08 5d, Jˆ7.9 Hz, 1H),
4.00±3.10 5m, 20H), 3.10 5t, Jˆ7.3 Hz, 2H), 2.88 5d, Jˆ
11.3 Hz, 1H), 2.56 5m, 2H), 2.40 5m, 1H), 2.05 5m, 2H), 1.90
5s, 15H), 1.70 5m, 1H); 13C NMR 575 MHz, D2O) d 179.5,
98.7, 95.6, 80.0, 79.1, 72.8, 72.0, 71.0, 67.7, 67.6, 59.8,
58.6, 53.7, 52.4, 50.3, 47.8, 47.7, 35.9, 27.5, 21.5;
[a]Dˆ132.8 5c 1.04, H2O).
4.3.10. Compound 8. To a solution of 7 5400 mg,
0.57 mmol) in CH2Cl2 58 mL) was added HBF4´Et2O
554% in Et2O, 0.072 mL, 0.63 mmol). After the reaction
was complete, a few drops of Et3N were added, the mixture
was concentrated, the residue was dissolved in EtOAc,
washed with water, brine and the organic layer dried over
MgSO4. The solvent was removed under vacuum and the
resulting crude solid was puri®ed by ¯ash chromatography
5EtOAc/hexanes, 3:7) to give 8 5329 mg, 75%) as a white
1
4.3.6. Compound 1f. Quantitative; H NMR 5400 MHz,
D2O) d 5.49 5d, Jˆ3.5 Hz, 1H), 5.13 5d, Jˆ8.7 Hz, 1H),
4.46 5d, Jˆ7.9 Hz, 1H), 4.12±3.25 5m, 24H), 2.97 5d, Jˆ
11.5 Hz, 1H), 2.81 5m, 2H), 4.30 5m, 1H), 2.13 5dd, Jˆ11.5,
14.4 Hz, 2H), 1.91 5s, 12H), 1.76 5dd, Jˆ12.1, 13.4 Hz, 1H);

S. Hanessian et al. / Tetrahedron 57 02001) 3255±3265
3263
1
solid; H NMR 5300 MHz, CDCl3) d 8.06±8.01 5m, 10H),
4.3.14. Compound 13. To a solution of 12 5517 mg,
0.58 mmol) in DMF 53 mL) was added allyl bromide
50.10 mL, 1.16 mmol) and tetrabutylammonium iodide
5428 mg, 0.116 mmol). After stirring at 208C for 15 min,
LiHMDS 51.0 M in THF, 0.695 mL) was added and the
resulting mixture was stirred for a further 1 h, quenched
with a few drops of 1N NH4Cl and the solvent was evapo-
rated. The residue was dissolved in EtOAc and washed with
1N HCl, NaHCO3 5satd.), water, brine and dried over
Na2SO4. The solvent was evaporated under vacuum and
the crude solid was puri®ed by ¯ash chromatography
5EtOAc/hexanes, 45:55) to give 13 5230 mg, 43%) as a
7.97±7.25 5m, 15H), 5.92 5t, Jˆ9.7 Hz, 1H), 5.69 5t, Jˆ
9.8 Hz, 1H), 5.52 5t, Jˆ9.0 Hz, 1H), 5.20 5broad t, Jˆ
5.3 Hz, 1H), 4.94 5dd, Jˆ12.3, 28.7 Hz, 2H), 4.83 5d, Jˆ
7.9 Hz, 1H), 4.68 5dd, Jˆ3.0, 12.2 Hz, 1H), 4.46 5dd, Jˆ5.2,
12.2 Hz, 1H), 4.15 5m, 1H), 3.96 5m, 1H), 3.49 5m, 2H); 13C
NMR 5100 MHz, CDCl3) d 165.9, 165.6, 165.1, 165.0,
156.2, 136.4, 133.4, 133.2, 133.1, 133.1, 129.7, 129.6,
129.3, 128.9, 128.5, 128.3, 128.2, 127.9, 101.4, 72.5, 72.2,
71.8, 69.4, 69.3, 66.4, 62.8, 40.7;[ a]Dˆ122.3 5c 4.30,
CHCl3);HRMS for
C
44H39NO12 calcd 5M1H1)
774.25507, found 774.25220.
1
white solid; H NMR 5300 MHz, CDCl3) d 7.35±7.26 5m,
4.3.11. Compound 9. To a solution of 8 5350 mg,
0.45 mmol) in MeOH 52 mL) was added a solution of
NaOMe 50.5 M in MeOH, 0.45 mL) dropwise at rt. The
reaction mixture was stirred at room temperature until
completion 5approximately 1 h) then the reaction mixture
was neutralized by addition of Amberlite IR-1205H1). The
resin was ®ltered off, the solution was concentrated under
vacuum, the residue was diluted with water and lyophilized
15H), 5.82±5.60 5m, 1H), 5.47 5broad s, 1H), 5.34±4.75 5m,
10H), 4.25±3.92 5m, 6H), 3.90±3.40 5m, 4H), 2.37 5m, 1H),
2.01 5s, 3H), 1.96 5s, 3H), 1.93 5s, 3H), 1.85 5s, 3H), 1.70±
1.50 5m, 1H); 13C NMR 5100 MHz, CD3OD) d 170.9, 170.7,
170.5, 169.2, 155.6, 155.5, 136.3, 136.2, 136.0, 133.5,
128.4, 128.3, 128.3, 128.1, 128.0, 127.9, 127.8, 117.1,
98.7, 81.6, 80.0, 45.9, 73.8, 71.1, 68.3, 67.9, 66.8, 66.6,
66.5, 62.2, 53.6, 50.3, 49.8, 34.0, 20.7, 20.5, 20.4, 20.3;
[a]Dˆ138.2 5c 2.45, CHCl3);HRMS for C 44H51N3O17
calcd 5M1H1) 934.35900, found 934.36096.
1
to give 9 5145 mg, 90%) as a ¯uffy white solid; H NMR
5400 MHz, D2O) d 7.42 5m, 5H), 5.11 5s, 2H), 4.42 5d,
Jˆ8.0 Hz, 1H), 4.00±3.85 5m, 2H), 4.80±3.60 5m, 2H),
3.55±3.30 5m, 5H), 3.25 5t, Jˆ8.5 Hz, 1H); 13C NMR
5100 MHz, D2O) d 159.2, 137.2, 129.6, 129.2, 128.5,
103.3, 76.7, 76.4, 73.9, 70.4, 69.8, 67.7, 61.5, 41.2;[ a]Dˆ
218.1 5c 1.40, H2O);HRMS for C 16H23NO8 calcd 5M1H1)
357.142367, found 357.141093.
4.3.15. Compound 14. A solution of 13 5705 mg,
0.76 mmol) in CH2Cl2 514 mL) was cooled at 2788C,
ozone was bubbled until the solution turned light blue,
after which argon was bubbled through. The mixture was
treated with PPh3 5297 mg, 1.13 mmol) and warmed up to
room temperature. The solvent was removed under vacuum
and the crude solid puri®ed by ¯ash chromatography
5EtOAc/hexanes, 1:1) to give 14 5590 mg, 84%) as a
4.3.12. Compound 10. To a solution of 9 5233 mg,
0.65 mmol) in AcOH 52 mL, 80% in water) was added
10% Pd/C 5approximately 10 mg) and stirred under 1 atm
of hydrogen at rt for 2 h. The mixture was ®ltered through a
Celite pad, concentrated, diluted with water and lyophilized
1
white solid; H NMR 5300 MHz, CDCl3) d 9.20 5s, 1H),
7.40±7.20 5m, 15H), 5.45±4.80 5m, 11H), 4.32±3.90 5m,
5H), 3.88±3.45 54H), 2.40 5broad d, Jˆ12.4 Hz, 1H), 2.01
5s, 3H), 1.93 5s, 3H), 1.85 5s, 3H), 1.84 5s, 3H), 1.50±1.33
5m, 1H); 13C NMR 5100 MHz, CD3OD) d 198.1, 170.8,
170.6, 169.1, 155.6, 155.4, 155.3, 136.2, 136.1, 135.9,
132.0, 131.9, 128.5, 128.4, 128.3, 128.2, 128.0, 127.9,
99.1, 83.7, 80.0, 77.9, 71.0, 68.1, 67.9, 66.9, 66.8, 66.6,
61.9, 53.5, 49.8, 34.0, 29.5, 20.6, 20.5, 20.4, 20.3;
[a]Dˆ134.8 5c 1.51, CHCl3);HRMS for C 46H53N3O18
calcd 5M1H1) 936.34021, found 936.34500.
1
to give 10 5175 mg, 95%) as a ¯uffy white solid; H NMR
5300 MHz, D2O) d 4.49 5d, Jˆ7.9 Hz, 1H), 4.17±4.03 5m,
1H), 4.00±3.84 5m, 2H), 3.70 5dd, Jˆ5.6, 15.0 Hz, 1H),
3.52±3.15 5m, 6H), 1.90 5s, 3H); 13C NMR 5100 MHz,
D2O) d 102.9, 76.7, 76.3, 73.8, 70.3, 66.6, 61.4, 40.2,
24.0;[ a]Dˆ218.2 5c 0.85, H2O).
4.3.13. Compound 12. To a suspension of 11 52.00 g,
0.24 mmol) in pyridine 50.40 mL) were added DMF
50.30 mL) and acetic anhydride 50.104 mL, 1.1 mmol).
The mixture was stirred overnight, neutralized with HCl
52N) and extracted with EtOAc. The combined organic
extracts were washed with a solution of CuSO4 5satd.),
water, brine and dried over Na2SO4. The solvent was evapo-
rated under vacuum and the residue was puri®ed by ¯ash
chromatography 5CH2Cl2/MeOH, 95:5) to give 12 51.127 g,
4.3.16. Compound 15. A solution of 13 5410 mg,
0.44 mmol) in CH2Cl2 59 mL) was cooled at 2788C,
ozone was bubbled until the solution turned light blue,
after which argon was bubbled through. The reaction
mixture was warmed up to 08C and treated with NaBH4
566 mg, 1.76 mmol) in MeOH 52 mL). The mixture was
stirred for 30 min, warmed up to rt and a few drops of
AcOH were added to quench the reaction. The solvents
were removed under vacuum, the residue was dissolved in
EtOAc, washed with water, brine and dried over Na2SO4.
The solvent was removed and to a solution of the crude
white solid in CH2Cl2 54 mL) was added 2,4,6-collidine
50.074 mL, 0.56 mmol) followed by MsCl 50.043 mL,
0.56 mmol). After stirring for 36 h, the mixture was diluted
with CH2Cl2, washed with CuSO4 5satd.), water, brine, dried
over Na2SO4 and the solvent was evaporated. To a solution
of the resulting residue in DMF 55 mL) was added NaN3
5217 mg, 3.35 mmol). After stirring at 508C for 8 h, the
solvent was removed under vacuum, the residue was
1
46%) as a white solid; H NMR 5400 MHz, CDCl3) d
7.30±7.25 5m, 15H), 5.85 5broad s, 1H), 5.51 5broad s,
1H), 5.35±4.85 5m, 10H), 4.75 5broad s, 1H), 4.20±3.85
5m, 4H), 3.80±3.50 5m, 4H), 3.14 5broad s, 1H), 2.28 5d,
Jˆ12.5 Hz, 1H), 1.96 5s, 3H), 1.94 5s, 3H), 1.93 5s, 3H),
1.85 5s, 3H), 1.70±1.50 5m, 1H); 13C NMR 5100 MHz,
CD3OD) d 171.8, 170.7, 169.2, 156.1, 155.7, 136.3,
135.9, 128.4, 128.3, 128.1, 127.9, 127.8, 99.5, 82.6, 75.9,
74.5, 71.0, 68.2, 67.9, 66.8, 66.5, 61.7, 54.0, 50.3, 49.4,
33.5, 29.5, 20.7, 20.4, 19.2, 14.3;[ a]Dˆ153.2 5c 2.00,
44H51N3O17 calcd 5M1H1)
CHCl3);HRMS for
C
894.32965, found 894.32810.

3264
S. Hanessian et al. / Tetrahedron 57 02001) 3255±3265
dissolved in EtOAc, washed with water, brine, dried over
Na2SO4 and the solvent was evaporated to give 15 5253 mg,
60%) as a white solid; 1H NMR 5400 MHz, CDCl3) d 7.40±
7.20 5m, 15H), 5.65±5.50 5m, 1H), 5.22±4.90 5m, 12H),
4.84 5t, Jˆ9.9 Hz, 1H), 4.20±3.95 5m, 4H), 3.87±3.40 5m,
6H), 3.33±3.20 5m, 1H), 2.90±2.80 5m, 1H), 2.37±2.25 5m,
1H), 2.00 5s, 6H), 1.96 5s, 3H), 1.93 5s, 3H), 1.51±1.36 5m,
1H); 13C NMR 5100 MHz, CDCl3) d 170.9, 170.7, 170.6,
169.1, 155.6, 155.4, 136.2, 136.1, 135.9, 128.4, 128.4,
128.3, 128.2, 128.1, 128.0, 127.9, 99.0, 81.7, 80.4, 75.5,
3H), 1.96 5s, 3H), 1.93 5s, 3H), 1.87 5s, 3H), 1.55±1.10
5m, 8H);FAB C 59H73N5O19 calcd 5M1H1) 1156.5, found
1156.5.
4.4.3. Compound 17c. 75%; 1H NMR 5400 MHz, CDCl3) d
7.42±7.20 5m, 15H), 5.75±5.60 5m, 1H), 5.40±4.70 5m,
10H), 4.30±3.82 5m, 4H), 3.78±3.25 5m, 4H), 2.70±2.22
5m, 3H), 2.24 5s, 3H), 1.98 5s, 3H), 1.95 5s, 3H), 1.89 5s,
3H), 1.49 5s, 9H), 1.47 5s, 9H);FAB C 59H79N7O21 calcd
5M1H1) 1222.5, found 1222.7.
71.8, 70.9, 68.2, 68.1, 66.9, 66.8, 66.6, 62.2, 53.9, 50.4,
49.9, 34.2, 20.6, 20.5, 20.4, 20.3;IR cm
2953, 2106, 1731, 1531, 1229, 1033;[ a]Dˆ140.1 5c 3.50,
CHCl3);HRMS for C 46H54N6O17 calcd 5M1H1) 963.36237,
found 963.36020.
4.4.4. Compound 17d. 94%; 1H NMR 5400 MHz, CDCl3) d
7.40±7.22 5m, 20H), 5.45±4.75 5m, 14H), 4.23±4.00 5m,
3H), 3.83±3.30 5m, 10H), 2.85 5broad s, 4H), 2.50±2.15
5m, 4H), 2.22 5s, 3H), 1.95 5s, 3H), 1.90 5s, 3H), 1.88 5s,
3H);FAB C 58H69N5O19 calcd 5M1H1) 1140.5, found
1140.5.
21
3325, 3065,
4.3.17. Compound 16. A solution of 15 570 mg, 0.07 mmol)
in MeOH 50.7 mL) was treated with a catalytic amount of
NaOMe, stirred for 15 min and a few drops of DMF were
added to dissolve the white precipitate. After stirring for 1 h,
Amberlite IR-1205H1) was added to neutralize the reaction
mixture, the solvent was ®ltered and evaporated under
vacuum to give a white solid. This was dissolved in DMF
50.6 mL), PPh3 538 mg, 0.14 mmol) added, followed by one
drop of water. After stirring at 608C for 24 h, one drop of
AcOH was added, the solvents were removed under
vacuum, the resulting white solid was triturated with
EtOAc and ®ltered to give 16 557 mg, quantitative) as a
4.4.5. Compound 17e. 38%; 1H NMR 5400 MHz, CDCl3) d
7.40±7.22 5m, 25H), 5.65 5broad s, 1H), 5.42±4.82 5m,
12H), 4.80±4.60 5m, 1H), 4.75±3.94 5m, 4H), 3.80±3.30
5m, 6H), 3.37±2.95 5m, 6H), 2.60±2.30 5m, 4H), 1.96 5s,
3H), 1.92 5s, 3H), 1.90 5s, 3H), 1.83 5s, 3H);FAB
C66H78N6O21 calcd 5M1H1) 1291.5, found 1291.6.
4.5. General procedure for deprotection ,2a,b and 2d,e)
The appropriate pseudo-disaccharide 517a,b and 17d,e) was
treated with a catalytic amount of NaOMe in MeOH/THF
51:1, 2 mL). After stirring for 3 h at rt, the mixture was
concentrated. To the resulting residue in H2O/dioxane/
AcOH 520:20:1, 2 mL) was added 10% Pd/C 5approxi-
mately 10 mg) and the mixture was stirred under 1 atm of
hydrogen at rt for 3 h. The mixture was ®ltered through a
Celite pad, concentrated under vacuum, diluted with water
and lyophilized to afford 2a,b and 2d,e as ¯uffy white
solids.
1
white solid; H NMR 5400 MHz, CD3OD) d 7.45±7.23
5m, 12H), 7.15 5d, Jˆ7.0 Hz, 1H), 7.03 5d, Jˆ9.5 Hz, 1H),
6.95±6.85 5m, 1H), 5.22±4.85 5m, 10 H), 3.72±3.15 5m, 18
H), 2.62±2.50 5m, 2H), 1.85 5s, 3H), 1.80±1.68 5m, 1H),
1.40±1.25 5m, 1H); 13C NMR 5100 MHz, DMSO-d6) d
162.2, 157.7, 156.8, 156.5, 138.3, 138.1, 138.0, 134.4,
134.2, 133.1, 132.6, 132.5, 130.0, 129.9, 129.8, 129.7,
129.4, 128.9, 128.8, 128.6, 128.3, 98.5, 87.4, 79.0, 75.4,
73.5, 73.2, 71.7, 70.9, 66.5, 66.3, 66.1, 61.3, 56.9, 52.1,
51.0, 35.8;[ a]Dˆ132.6 5c 3.70, DMSO);HRMS for
C38H48N4O13 calcd 5M1H1) 769.32959, found 769.32660.
1
4.5.1. Compound 2a. Quantitative; H NMR 5400 MHz,
D2O) d 5.64 5d, Jˆ4.0 Hz, 1H), 4.25±4.12 5m, 1H), 4.08±
3.87 5m, 4H), 3.85±3.62 5m, 5H), 3.58±3.41 5m, 2H), 4.38±
3.20 5m, 8H), 2.47±4.39 5m, 1H), 1.95 5s, 15H), 1.78 5dd,
Jˆ6.5, 11.5 Hz, 1H); 13C NMR 5100 MHz, D2O) d 181.7,
95.8, 83.3, 77.0, 74.8, 73.5, 70.3, 69.8, 67.7, 60.9, 54.4,
50.6, 49.8, 48.7, 45.4, 36.7, 29.3, 23.7;[ a]Dˆ142.0 5c
1.00, H2O).
4.4. General procedure for reductive amination ,17a±e)
To a mixture of 14 50.034 mmol) and the appropriate amine
50.1 mmol) in MeOH 53 mL) was added AcOH 50.1 mL)
followed by NaBH3CN 51.0 M in THF, 0.1 mL). The
mixture was stirred at room temperature overnight until
disappearance of 14. The reaction mixture was diluted
with EtOAc 515 mL) and washed with a solution of
NaHCO3 5satd., 10 mL) and dried over Na2SO4. After
evaporation of the solvents, the residue was puri®ed by
¯ash chromatography 5CHCl3/EtOAc/MeOH, 7:2:1) to
give 17a±e as white solids.
1
4.5.2. Compound 2b. Quantitative; H NMR 5400 MHz,
D2O) d 5.63 5d, Jˆ3.8 Hz, 1H), 4.22±4.12 5m, 1H), 4.10±
3.60 5m, 9H), 3.55±3.42 5m, 3H), 3.40±3.20 5m, 4H), 3.04
5t, Jˆ8.1 Hz, 2H), 2.95 5t, Jˆ7.5 Hz, 2H), 2.43±2.35 5m,
1H), 2.00±1.60 5m, 25H), 1.48±1.32 5m, 2H); 13C NMR
5100 MHz, D2O) d 181.8, 95.0, 83.3, 76.0, 74.8, 73.3,
70.1, 69.7, 66.6, 60.9, 54.4, 50.6, 49.7, 48.2, 39.9, 29.0,
27.0, 25.7, 23.8, 23.6;[ a]Dˆ126.6 5c 1.00, H2O).
4.4.1. Compound 17a. 66%; 1H NMR 5400 MHz, CDCl3) d
7.40±7.22 5m, 20H), 5.60±5.45 5m, 1H), 5.30±4.72 5m,
10H), 4.25±3.96 5m, 8H), 3.85±3.00 56H), 2.70±2.20 5m,
4H), 2.20 5s, 3H), 1.96 5s, 3H), 1.93 5s, 3H), 1.87 5s, 3H);
FAB for C56H67N5O19 calcd 5M1H1) 1114.4, found 1114.4.
1
4.5.3. Compound 2c. Quantitative; H NMR 5400 MHz,
D2O) d 5.77 5d, Jˆ3.7 Hz, 2/7H), 5.74 5d, Jˆ3.7 Hz,
5/7H), 4.45±3.30 5m, 22H), 2.55±2.45 5m, 1H), 1.86 5dd,
Jˆ6.4, 12.6 Hz, 1H); 13C NMR 5100 MHz, D2O) d 164.3,
163.9, 163.6, 163.2, 157.8, 121.5, 118.6, 115.7, 94.3, 83.4,
75.2, 73.2, 69.6, 69.5, 66.5, 63.3, 60.7, 54.2, 50.7, 50.5,
49.7, 48.7, 46.8, 38.2, 28.6;[ a]Dˆ131.1 5c 1.00, H2O).
4.4.2. Compound 17b. 73%; 1H NMR 5400 MHz, CDCl3) d
7.40±7.22 5m, 20H), 5.35±4.70 5m, 16H), 4.25±4.97 5m,
4H), 3.80±3.35 5m, 6H), 3.23±3.10 5m, 2H), 2.60 5broad
s, 1H), 2.40 5broad s, 1H), 2.25 5broad s, 1H), 2.20 5s,

S. Hanessian et al. / Tetrahedron 57 02001) 3255±3265
3265
1
4.5.4. Compound 2d. Quantitative; H NMR 5400 MHz,
Tolbert, T. J.;Wong, C.-H. Angew. Chem., Int. Ed. 2000,
39, 1080. 5b) Wong, C.-H.;Hendrix, M.;Manning, D. A.;
Rosenbohm, C.;Greenberg, W. A. J. Am. Chem. Soc. 1998,
120, 8319. 5c) Alper, P. B.;Hendrix, M.;Sears, P.;Wong,
C.-H. J. Am. Chem. Soc. 1998, 120, 1965. 5d) Park, W. K. C.;
Auer, M.;Jaksche, H.;Wong, C.-H. J. Am. Chem. Soc. 1996,
118, 10150.
D2O) d 5.64 5d, Jˆ3.8 Hz, 1H), 4.10±4.00 5m, 1H), 3.98±
3.84 5m, 4H), 3.82±3.60 5m, 5H), 3.56±3.20 5m, 10H),
3.18±3.08 5broad s, 1H), 2.95±2.70 5m, 7H), 2.48±2.40
5m, 1H), 1.91 5s, 18H), 1.77 5t, Jˆ12.6 Hz, 1H); 13C NMR
5100 MHz, D2O) d 181.8, 95.4, 83.4, 76.8, 74.9, 73.1, 69.9,
69.7, 67.9, 60.9, 57.8, 54.4, 50.5, 50.1, 49.8, 43.4, 42.7,
29.1, 23.8;[ a]Dˆ131.4 5c 1.00, H2O).
10. For examples of dimeric aminoglycosides, see: 5a) Michael,
K.;Wang, H.;Tor, Y. Bioorg. Med. Chem. 1999, 7, 1361.
5b) Sucheck, S. J.;Wong, A. L.;Koeller, K. M.;Boehr,
D. D.;Draker, K.;Sears, P.;Wright, G. D.;Wong, C.-H.
J. Am. Chem. Soc. 2000, 122, 5230.
1
4.5.5. Compound 2e. Quantitative; H NMR 5400 MHz,
D2O) d 5.71 5d, Jˆ3.8 Hz, 1H), 4.12±4.03 5m, 1H),
4.00±3.60 5m, 9H), 3.56±3.22 5m, 4H), 3.15±3.05 5m,
4H), 2.97±2.75 5m, 5H), 2.48±2.37 5m, 1H), 1.75 5dd,
Jˆ6.8, 12.4 Hz, 1H); 13C NMR 5100 MHz, D2O) d 181.8,
94.6, 83.6, 75.5, 74.7, 73.6, 70.3, 69.7, 69.4, 60.9, 54.5,
52.9, 51.5, 50.8, 50.4, 49.8, 37.5, 29.3, 23.8;[ a]Dˆ132.0
5c 1.00, H2O).
11. Ding, Y.;Swayze, E. E.;Hofstadler, S. A.;Griffey, R. H.
Tetrahedron Lett. 2000, 41, 4049.
12. 5a) Roestamadji, J.;Grapsas, I.;Mobashery, S. J. Am. Chem.
Soc. 1995, 117, 80. 5b) Roestamadji, J.;Mobashery, S. Bioorg.
Med. Chem. Lett. 1998, 8, 3483.
Á
13. See for example: 5a) Hanessian, S.;Vate le, J.-M. J. Antibiot.
Â
1980, 33, 675. 5b) Hanessian, S.;Masse , R.;Nakagawa, T.
Â
Can. J. Chem. 1978, 56, 1509. 5c) Hanessian, S.;Masse , R.;
Capmeau, M. L. J. Antibiot. 1977, 10, 893.
Acknowledgements
14. While this work was in progress, neamine-based libraries of
aminoglycoside mimetics were published: 5a) Greenberg,
W. A.;Priestly, E. S.;Sears, P. S.;Alper, P. B.;Rosenbohm,
C.;Hendrix, M.;Hung, S.-C.;Wong, C.-H. J. Am. Chem. Soc.
1999, 121, 6527. 5b) Nunns, C. L.;Spence, L. A.;Slater, M. J.;
Berrisford, D. J. Tetrahedron Lett. 1999, 40, 9341.
We thank PathoGenesis Corporation for biological testing
and ®nancial support, and NSERC for generous ®nancial
assistance through a Medicinal Chemistry Chair Program.
M.T. acknowledges a fellowship from Fond pour la For-
Á
mation de Chercheurs et l'Aide a la Recherche 5FCAR).
15. Fourmy, D.;Recht, M. I.;Blanchard, S. C.;Puglisi, J. D.
Science 1996, 274, 1367.
References
16. Leclerc, F.;Cedergren, R. J. Med. Chem. 1998, 41, 175.
17. Hermann, T.;Westhof, E. J. Med. Chem. 1999, 42, 1250.
18. Carter, A. P.;Clemons, W. M.;Brodersen, D. E.;Morgan-
Warren, R. J.;Wimberly, B. T.;Ramakrishnan, V. Nature
2000, 407, 340.
1. Mingeot-Leclercq, M. P.;Glupczynski, Y.;Tulkens, P. M.
Antimicrob. Agents Chemother. 1999, 43, 727.
2. Mingeot-Leclercq, M. P.;Tulkens, P. M. Antimicrob. Agents
Chemother. 1999, 43, 1003.
3. Davies, J. Science 1994, 264, 375.
19. GRID version 17 from Molecular Discovery Inc., Oxford, UK.
Probes: O1 5hydroxyl oxygen), N31 5ammonium group).
5a) Goodford, P. J. J. Med. Chem. 1985, 28, 849. 5b) Boobbyer,
D. N. A.;Goodford, P. J.;McWhinnie, P. M.;Wade, R. C.
J. Med. Chem. 1989, 32, 1083. 5c) Wade, R. C.;Clark, K. J.;
Goodford, P. J. J. Med. Chem. 1993, 36, 140. 5d) Wade, R. C.;
Clark, K. J.;Goodford, P. J. J. Med. Chem. 1993, 36, 148.
20. Tok, J. B. H.;Rando, R. R. J. Am. Chem. Soc. 1998, 120, 8279.
21. Kuwahara, R.;Tsuchiya, T. Carbohydr. Res. 1996, 293, 15.
4. 5a) Woo, P. W. K.;Dion, G. L.;Bartz, Q. R. Tetrahedron Lett.
1971, 2621, 2625. 5b) Haskell, T. H.;Rodebaugh, R.;Plessas,
N.;Watson, D.;Westland, R. D. Carbohydr. Res. 1973, 28,
263.
5. Edson, R. S.;Terrell, C. L. Mayo. Clin. Proc. 1999, 74, 519.
6. For recent reviews, see: 5a) Berko, A. H. Tetrahedron 1996,
52, 331. 5b) In The Organic Chemistry of b-Lactams;Georg,
G. I., Ed.;VCH: New York, 1993 5and references cited
therein). 5c) Nauhaus, F. C.;Georgopapadakou, N. H. In
Emerging Targets in Antibacterial and Antifungal Chemother-
apy;Sutcliffe, J., Georgopapadakou, N. H., Eds.;Chapman &
Hall: New York, 1992.
Â
22. Hanessian, S.;Takamoto, T.;Masse , R.;Patil, G. Can. J.
Chem. 1978, 56, 1482.
23. Atwell, G. J.;Denny, W. A. Synthesis 1984, 1032.
24. Feichtinger, K.;Sings, H. L.;Baker, T. L.;Matthews, K.;
Goodman, M. J. Org. Chem. 1998, 63, 8432.
7. For recent reviews, see: 5a) Gootz, T. D.;Brighty, K. E. Med.
Res. Rev. 1996, 16, 433. 5b) Kidwai, M.;Missa, P.;Kumar, R.
Curr. Pharm. Des. 1998, 4, 101. 5c) Fung, A. K. L.;Shen, L. L.
Curr. Pharm. Des. 1999, 5, 515. 5d) Chu, D. L.;Plattner, J. J.;
Katz, L. J. Med. Chem. 1996, 39, 3853. 5e) Li, Q.;Mitscher,
L. A.;Shen, L. L. Med. Res. Rev. 2000, 20, 231.
25. 5a) Lou, B.;Huynh, H. K.;Hanessian, S. In
Preparative
Carbohydrate Chemistry;Hanessian, S., Ed.;Marcel Dekker:
New York, 1996;p. 431. For other syntheses see: 5b) Ashton,
P. R.;Everitt, S. R. L.;Gomez-Lopez, M.;Jayaraman, N.;
Stoddart, J. F. Tetrahedron Lett. 1997, 38, 5691. 5c) Jayaraman,
N.;Stoddart, J. F. Tetrahedron Lett. 1997, 38, 6767.
26. Umezawa, S.;Koto, S.;Tatsuta, K.;Tsumura, T. Bull. Chem.
Soc. Jpn. 1969, 42, 529.
8. Recht, M. I.;Fourmy, D.;Blanchard, S. C.;Dahlquist, K. D.;
Puglisi, J. D. Mol. Biol. 1996, 262, 421.
9. See for example: 5a) Sucheck, S. J.;Greenberg, W. A.;