Practical syntheses of B disaccharide and linear B type 2 trisaccharide - Non-primate epitope markers recognized by human anti-α-Gal antibodies causing hyperacute rejection of xenotransplants

Article abstract of DOI:10.1016/S0040-4020(01)00196-X

Synthetic protocols are presented for the elaboration of Galα1→3GalOR and Galα1→3Galβ1→4GlcNAcOR di- and trisaccharides that use a common Gal donor/acceptor unit, and are potentially adaptable to scale-up.

Full text of DOI:10.1016/S0040-4020(01)00196-X

TETRAHEDRON
Pergamon
Tetrahedron 57 32001) 3267±3280
Practical syntheses of B disaccharide and linear B type 2
trisaccharideÐnon-primate epitope markers recognized
by human anti-a-Gal antibodies causing hyperacute rejection
of xenotransplants
Stephen Hanessian,a,p Oscar M. Saavedra,a Vincent Mascitti,a Wolfgang Marterer,b
Reinhold Oehrleinc and Ching-Pong Makb
a
Â
Â
Department of Chemistry, Universite de Montreal, P.O. Box 6128, Succursale Centre-ville, Montreal, Quebec, Canada H3C 3J7
bNovartis Pharma AG, Chemical and Analytical Development, Basel CH-4002, Switzerland
cCiba Specialty Chemicals, Basel CH-4002, Switzerland
Received 19December 2000; accepted 12 February 2001
AbstractÐSynthetic protocols are presented for the elaboration of Gala1!3GalOR and Gala1!3Galb1!4GlcNAcOR di- and tri-
saccharides that use a common Gal donor/acceptor unit, and are potentially adaptable to scale-up. q 2001 Elsevier Science Ltd. All rights
reserved.
1.Introduction
looms as a real threat, as discussed below.5 Secondly, in the
advent of a successful transplant, extreme care must be
exercised to avoid the transfer, either directly or through a
dormant genetic mechanism, of the porcine endogenous
retrovirus and other retroviruses to man.6 This socio-
medical issue can, in principle, be resolved by breeding
genetically modi®ed pigs that do not encode for the virus,
and its implications are outside the scope of this paper.
The replacement of vital organs in humans 3allotransplanta-
tion) is arguably one of the most dramatic scienti®c accom-
plishments in the annals of medical history. Through
enormous advances and heroic efforts in the ®eld of trans-
plantation, such procedures are quasi routine today for a
number of organs that include the heart, kidney, and liver
for example. In spite of these monumental successes, the
continued practice of one of the noblest of human life-
saving procedures is severely jeopardized by the limited
availability of suitable donors.1
Of greater immediate concern, however, are the immuno-
logic barriers to discordant xenotransplantation from pig to
man.5 A major cause for hyperacute rejection of a xenograft
would be the result of binding anti-pig antibodies to
antigens expressed on the endothelium of the donated
organ. a-Gal containing epitopes on pig tissues are abun-
dantly expressed, and recognized by anti-a-Gal antibodies,
which constitute approximately 1% of circulating antibodies
3IgG, IgM and IgA) in humans.5,7 In fact, such antibodies
bind to a-GalR containing oligosaccharide epitopes such as
Gala1!3GalOR 3B disaccharide antigen group) 1 and
Gala1!3Galb1!4GlcNAcOR 3linear B type 2 antigen
group) 2 among others4,8 3Fig. 1).
A possible solution has been considered through xeno-
transplantation, where suitable animal donors would be
used. Although phylogenetically close to man, non-human
primates such as apes, monkeys and baboons are not suitable
donors for various ethical and epidemiological reasons.2 Pigs,
however, appear to present a good alternative3 since they
can be bred in large numbers, even with genetically engi-
neered variants.4 Moreover, they are anatomically and
physiologically similar to man with suitable heart sizes. In
spite of this somewhat futuristic notion with obvious
advantages if successfully implemented, the practice of
xenotransplantation from pig to man is plagued by at least
two major obstacles. Firstly, the phenomenon of rejection
Curiously, the Gala1!3Gal epitope is absent in all human
tissue because a1!3Gal transferase9 is not expressed
except in certain malignancies.5,10 They do however
produce large amounts of anti-a-Gal antibodies as part of
a natural class of immunoglobulins, perhaps as a preventive
measure toward bacteria and cells of other species.11 It is
clear then why the binding of human anti-a-Gal antibodies
to a-GalOR containing epitopes of vascularized organ
Keywords: oligosaccharides; glycoside synthesis; new donors.
Corresponding author. Tel.: 1514-343-6738; fax: 1514-343-5728;
e-mail: hanessia@ere.umontreal.ca
p
0040±4020/01/$ - see front matter q 2001 Elsevier Science Ltd. All rights reserved.
PII: S0040-4020301)00196-X

3268
S. Hanessian et al. / Tetrahedron 57 52001) 3267±3280
Figure 1.
tissues results in hyperacute rejection. To achieve successful
`accommodation'12 3adaptation, anergy) of the transplant,
one must deplete the anti-a-Gal antibodies from the
recipient before the new organ is placed.5 Although there
are other barriers to successful xenotransplantation even if
hyperacute rejection is minimized, such as acute vascular
and cell-mediated phenomena, the notion of neutralizing
anti-a-Gal natural antibodies with synthetic a-GalOR
containing oligosaccharides prior to organ transplantation
remains as an attractive protocol. It appears that once
`removed', the acquired acceptance 3accommodation) can
persist, even when the humoral antibodies are restored, as
evidenced in allografts.13 Once the new organ is in place and
antibody activity is curtailed, immunotherapy using
immunosuppressant drugs can be initiated to ensure the
patient's well being and to maintain the new organ.
need to devise practical syntheses of the Gala1-3GalOR
3B disaccharide) 1 and Gala1!3Galb-1!4GlcNAcOR
3linear B type 2 trisaccharide) 2.
Although several syntheses are known,16±22 we were par-
ticularly interested in devising synthetic protocols that
avoided the use of thiol-based reagents, hydrolytically labile
glycosyl donors, and potentially toxic reagents, with the
prospects of adapting the protocol to potentially produce
relatively large quantities of 1 and/or 2 in a process group
environment. In order to explore practical methods to access
the intended targets 1 and 2, we chose a strategy that
capitalizes on the ability of a common Gal unit to act as a
donor and acceptor. We have previously shown that 2-
pyridyl and 3-methoxy-2-pyridyl 3MOP) glycosides are
excellent anomeric activators under mild conditions.23
Thus, unprotected MOP b-d-galactopyranoside 3 3Fig. 1)
affords alkyl a-d-galactopyranosides 3and oligosaccharides)
upon treatment with a suitable alcohol or partially protected
MOP glycoside.24 Activation of the newly formed di-
saccharide, for example, and reaction with a suitably
protected MOP glycoside allows for an iterative oligo-
saccharide synthesis. O-Protected MOP b-d-galactopyrano-
sides can serve as glycosyl donors or acceptors depending
on the nature of the O-protecting group.
Extensive studies have shown that carbohydrate therapy in
xenotransplantation with the aim of neutralizing anti-a-Gal
antibodies is a viable experimental protocol. Although the
clinical aspects of the procedure are not resolved, one
extreme but successful protocol is the use of pretransplant
extracorporal immunoadsorption with columns containing
pertinent a-GalOR epitope motifs that can entrap anti-
a-Gal antibodies from the `patient's' blood that is perfused
through the column.2b,8c Transplantation could then be done
when a low titer of the anti-a-Gal antibodies is reached.
Another approach relies on speci®c intravenous a-GalOR
therapy as demonstrated in baboon allografts.14
Fig. 1 illustrates the common Gal donor/acceptor strategy in
conjunction with the synthesis of 1 and 2. It should be
pointed out that MOP glycoside donors which contain par-
ticipating groups at C-2 3ester) will lead to 1,2-trans-glyco-
sides, while those with non-participating groups 3ex. benzyl)
will afford the 1,2-cis-glycosides as major products,25 as in
These and other studies directed at exploiting xenoreactive
antigen±human antibody interactions15 has instigated a

S. Hanessian et al. / Tetrahedron 57 52001) 3267±3280
3269
Scheme 1. 3a) i. HBr, Ac2O, AcOH, 2 h rt. for 5 ii. silver 2-pyridoxide, toluene, re¯ux, 1 h, 71%; for 6 ii. silver 3-methoxy-2-pyridoxide, toluene, re¯ux, 1 h,
86%. 3b) MeONa, MeOH, rt, 3-6 h, 94±95% 3c) i. TBDPSCl, imidazole, DMF, 6 h, rt, 78±81% ii. MeC3OEt)3, pyridinium tri¯ate, DCM, 45±60 min, rt iii.
BzCl, DMAP, DCM, 1 h 30 min, rt, 3d) for RˆH: i. 90% AcOH, 10 min, rt, 76%; for RˆOMe: ii. AcOH, AcONa, H2O pHˆ3±4, 1 h, 67%. 3e) DCM, 1 h, rt,
for 10a: HBF4.Et2O, 80%; for 10b: HBF4.EtO, ,80%; for 11a: HBF4.Et2O, 80% for TMStri¯ate, 78% or Cu3OTf)2, 65%; for 11b: HBF4.Et2O, 72%. 3f) for
14a: DCM, 2 h, rt, Yb3OTf)3, 76% or toluene, 1 d, rt Cu3OTf)2, 60%; for 14b: toluene, 2d, 51%. 3g) i. MeONa, MeOH, rt, 48 h. ii TBAF, THF, rt, 24 h. iii. 20%
Pd3OH)2/C, H2, 60 psi, dioxane/water, 1 h, then HCl, H2, 60 psi, rt, overnight.
well precedented examples using other anomeric activating
groups.26 Due to the much decreased reactivity of MOP
glycosides that are only partially protected with ester
groups,27 they can also act as acceptors when allowed to
react with other more reactive MOP glycosyl donors.
to pyridyl and MOP Gal acceptors 10 and 11, with ether
and ester C-6 substituents, we studied the coupling reaction
with 6-N-benzyloxycarbonylamino 1-hexanol in the
presence of a variety of activators. The Lewis acids TMS
tri¯ate, Yb3TfO)3,30 and Cu3TfO)2,25 and the protic acid
HBF4´Et2O31 were effective activators, affording the alkyl
b-d-galactopyranosides 12a and 12b in good yields. As
expected, the glycosylation reaction was selective, favoring
the acceptor alcohol 31.5 equiv.), with no trace of self-
condensation products arising from 10a,b or 11a,b, acting
as donor and acceptor to each other. It was important to use
pre-dried Yb3TfO)3 and Cu3TfO)2 for ef®cient glycosyl-
ations. The reaction between the donor 13 and the acceptor
12a was best achieved in the presence of dry Yb3TfO)3 as
activator, affording a 76% yield of the intended disaccharide
14a. With Cu3TfO)2, toluene was found to be better than
dichloromethane as solvent, but conditions needed to be
rigorously anhydrous. The yield of the glycosylation was
found to be diminished when the dibenzoate 12b was used
as an acceptor. Sequential deprotection of 14a afforded the
intended disaccharide hapten 15.
In order to test the feasibility of this strategy we considered
the synthesis of the Gala1!3GalOR motif 1 in the form of
its 6-aminohexyl b-d-glycoside as a representative hapten
®rst 3Scheme 1). Pyridyl28 and MOP b-d-galactopyrano-
sides were conveniently prepared from b-d-galactopyranose
pentaacetate 4 in two steps to afford ®rst the peracetates 5
and 6, then the free glycosides 7 and 3, respectively. Selec-
tive protection of the primary hydroxy group followed by
treatment with trimethylorthoacetate led to the correspond-
ing orthoesters, which where benzoylated to give 8 and 9,
respectively. Treatment with 90% acetic acid afforded the
partially esteri®ed MOP glycosides 10 and 11 in excellent
yield. Previous work in our laboratory29 had shown that
compounds related to the corresponding orthoamide, easily
prepared from 3 by selective protection then by treatment
with N,N-dimethylacetamide dimethyl acetal, also afforded
the diester 10, but the cleavage was not as regioselective as
in the case of the orthoesters 8 or 9. As a parallel series, we
also prepared the 2,6-dibenzoate analogs of 10 and 11.
The above sequence demonstrated the successful utilization
of a common Gal donor/acceptor to construct the Gala1!b
GalOR disaccharide. For the synthesis of 2 we considered
two approaches 3Fig. 1). In the ®rst, we envisaged the
stepwise construction of the trisaccharide, utilizing a substi-
tuted MOP Galb1!4 donor and an MOP GlcNAc3or NPht)
acceptor, followed by coupling with MOP Gala1!3 donor
Perbenzylation of MOP b-d-galactopyranoside under stan-
dard conditions gave the perbenzylated ether 13 which
would act as the a-orienting Gal donor.25 Having access

3270
S. Hanessian et al. / Tetrahedron 57 52001) 3267±3280
13. A more practical approach would capitalize on the ready
availability of alkyl N-acetyl lactosaminides via chemo-
enzymatic routes as acceptor,32 and using 13 as a
Gala1!3 donor.
methane required 2 equiv. of donor 13, affording 63% of
the desired Gala1!3 trisaccharide 27. Portionwise addition
of 1 equiv. of 13 ®rst and another equivalent after 4 h was
found to give better results than addition in one portion. The
reaction with 26 was slower in the presence of Cu3TfO)2,
but only 1 equiv. of donor 13 was required to give a 60%
yield of 27. Removal of traces of moisture by using
previously dried activator was found to be highly bene®cial.
In both cases, a minor by-product was identi®ed as the
2,3,4,6-tetra-O-benzyl b-d-galactopyranosyl N-3-methoxy-
2-pyridone 28. We have observed such N-glycosides in
glycosylations of MOP donors with somewhat less reactive
acceptors. They presumably result from the condensation of
the 3-methoxy-2-pyridone formed in the reaction or cleaved
due to adventitious moisture with the glycosyl cation.
Scheme 2 illustrates the ®rst approach in which 2-deoxy-2-
phthalimido-b-d-glucopyranose pentaacetate 16 was
converted to the corresponding MOP glycoside 17. Treat-
ment of 17 with 3-benzyloxycarbonylamino 1-propanol in
the presence of HBF4´Et2O in dichloromethane led to the
expected b-d-glycoside 18 in 65% yield. Deacetylation and
selective protection of the primary hydroxy group afforded
19 in excellent yield. Glycosylation with 2,3,4,-tri-O-
benzoyl 6-O-tert-butyldiphenylsilyl MOP b-galactopyrano-
25
side 20 in the presence of Cu3TfO)2 as activator gave the
intended Galb1!4GlcNPht disaccharide 21 in 64% yield
accompanied by the regioisomeric glycoside 22 as a minor
product. Hydrolysis of the ester groups in the presence of
sodium methoxide in methanol followed by hydrazinolysis
and N-acetylation afforded 23.
There remained to deprotect 27 en route to the intended
target 2. Removal of the TBDPS protecting groups with
¯uoride ion was slow and afforded mixtures of esters, pos-
sibly resulting from ester migration. On the other hand,
deesteri®cation with sodium methoxide in methanol
proceeded smoothly, after which the silyl ethers could be
easily removed. Hydrogenolysis of the N-benzyloxy-
carbonyl and benzyl ether groups proved problematic,
resulting in mixtures. However, using 20% palladium
hydroxide on charcoal 3Pearlman's catalyst) in aqueous
dioxane proved successful, affording the desired trisaccharide
2 as a colorless powder.
The alternative strategy utilizing a preformed 3-benzyl-
oxylcarbonylamino b-N-acetyl lactosaminide 24,32 was
next investigated 3Scheme 3). Treatment with tert-butyl-
diphenylsilyl chloride afforded the selectively protected
ether derivative 23 in excellent yield identical to the product
obtained previously 3Scheme 2). At this point we adapted
the orthoester protocol to achieve selective esteri®cation of
the 3,4-diol in the terminal Gal unit, as was successfully
implemented for the synthesis of 1 3Scheme 1). Thus, treat-
ment of 23 with trimethyl orthoacetate in the presence of
pyridinium tri¯ate afforded the corresponding orthoester 25,
which was converted to the diacetate 26 upon treatment with
acetic acid. We next studied the critical a1!3 galactosyl-
ation reaction with 13 as donor and 26 as acceptor in the
presence of two activators. Using Yb3TfO)3 in dichloro-
We have reported on synthetic protocols for the elaboration
of hapten-like motifs based on B disaccharide 1 and linear
B type 2 trisaccharide 2. A noteworthy feature in these
protocols is the utilization of a common Gal unit as donor
and acceptor having the same leaving group but differing in
the O-substituents. The syntheses have elements of practi-
cality and the potential for scale-up since they avoid the use
Scheme 2. 3a) i. HBr, AcOH, Ac2O, rt, 20 h. ii. silver 3-methoxy-2-pyridoxide, toluene, re¯ux 1 h, 50% two steps. 3b) HBF4´Et2O, DCM, 12 h, rt, 65%. 3c) i.
MeONa, MeOH, overnight, rt, 91%. ii. TBDPSCl, imidazole, DMF, rt, overnight, 92%. 3d) Cu3OTf)2, DCM, rt, 6 h, 64%. 3e) i. MeONa/MeOH, rt, overnight.
ii. hydrazine hydrate, EtOH, re¯ux, 4 h. iii. Ac2O, MeOH, 61%.

S. Hanessian et al. / Tetrahedron 57 52001) 3267±3280
3271
Scheme 3. 3a) TBDPSCl, imidazole, DMF, 6 h, rt. 3b) MeC3OEt)3, pyridinium tri¯ate, DCM, 45±60 min, rt. 3c) i. Ac2O, DMAP, DCM, 1 h. ii. 90% AcOH, 10
min, rt, 86%. 3d) Cu3OTf)2, toluene, 20 h, 27, 60%; or 2 equiv. 13, Yb3OTf)3, DCM, 8 h, 27, 63%, 28 also isolated. 3e) i. MeONa, MeOH, rt, 48 h. ii. TBAF,
THF, rt, 24 h. iii. 20% Pd3OH)2/C, H2, 60 psi, dioxane/water, 1 h, then HCl, H2, 60 psi, rt, overnight, 65%.
of toxic heavy metal salts, thiol reagents, or unstable
intermediates.
was poured under heavy stirring into a solution of silver
nitrate 317.8 g, 1 equiv.) in H2O 370 mL). The mixture
was stirred for 15 min, the slurry was ®ltered, washed
with water 3500 mL), MeOH 3100 mL) and dried under
vacuum overnight. The crusty material thus obtained was
pulverized and the powder further dried overnight under
vacuum to give silver 2-pyridoxide 320.5 g, 101.5 mmol,
97%) as an amorphous white solid.
2.Experimental
2.1. 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 CH2Cl2, from CaH2.
All commercially available reagents were used without
further puri®cation. All reactions were performed under
nitrogen atmosphere. NMR 31H, 13C) spectra were recorded
on AMX-300 and ARX-400 spectrometers. The term [32)]
in 13C data refers to the sign of the corresponding peak in the
DEPT 135 NMR experiment. Low- and high-resolution
mass spectra were recorded on VG Micromass, Ael-
MS902 or Kratos MS-50 spectrometers using fast atom
bombardment 3FAB) or electrospray 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 340±60 mm) silica gel at increased pressure.
2.1.2. 3-Methoxy-2-/1H)-pyridone. To a 1.4 M aqueous
solution of sodium hydroxide at 08C was added 2,3-di-
hydroxypyridine 3100 g, 0.9mol). After 15 min dimethyl-
sulfate 385.2 mL, 1 equiv.) was added carefully at 08C and
the mixture was stirred at room temperature for 3 h.
Neutralization with acetic acid till pH 7, extraction of the
crude product with chloroform 310£1 L) and concentration
of the organic layer gave the title compound, which was
recrystallized in chloroform to provide pure 3-methoxy-2-
31H)-pyridone as cream-colored needles 385.1 g, 75.5%):
1
mp 1188C. H NMR 3CDCl3, 400 MHz); d: 7.04 3d, Jacˆ
6.5 Hz, 1H, H±C), 6.76 3d, Jabˆ7.4 Hz, 1H, H-B), 6.23 3dd,
Jabˆ7.4 Hz, Jacˆ6.5 Hz, 1H, H±A), 3.84 3s, 3H,OMe). 13C
NMR 3CD3OD, 100 MHz); d: 160.3 3CO-pyridyl), 149.6
3CO-pyridyl), 125.3 3CH-pyridyl), 114.7 3CH-pyridyl),
106.5 3CH-pyridyl), 55.7 3OMe). HR-FABMS calcd for
C6H7O2N m/z 125.0477; found 125.0479.
2.1.3. Silver 3-methoxy-2-pyridoxide. 3-Methoxy-2-31H)-
pyridone 36 g, 48 mmol) was dissolved in a solution of
sodium hydroxide 31.92 g, 1 equiv.) in water 3140 mL).
This solution was poured under heavy stirring into a
2.1.1. Silver 2-pyridoxide. 2-Hydroxypyridine 310 g,
105.14 mmol) was dissolved in a solution of sodium
hydroxide 34.2 g, 1 equiv.) in H2O 370 mL). This solution

3272
S. Hanessian et al. / Tetrahedron 57 52001) 3267±3280
solution of silver nitrate 38.15 g, 1 equiv.) in water 370 mL),
the mixture was stirred for 30 min, the slurry was ®ltered,
washed with water 3500 mL), methanol 3100 mL) and dried
under vacuum overnight. The crusty material thus obtained
was pulverized and the powder further dried overnight
under vacuum to give silver 3-methoxy-2-pyridoxide as a
purple powder 310.5 g, 45 mmol, 94%).
71.1, 71.0, 68.3, and 66.93C-2 to C-5), 61.0 [3 2), C-6], 55.8
3OCH3), 20.6, and 20.5 3COCH3). HR-FABMS calcd for
C20H26O11N m/z 456.1505; found 456.1496.
2.1.6. 2-Pyridyl b-d-galactopyranoside /7). To a solution
of 5 310.99 g, 25.84 mmol) in MeOH 385 mL) was added
sodium methoxide 30.5N in MeOH, 0.2 mL) and the
reaction mixture was stirred for 6 h at room temperature.
The solution was neutralized with Amberlitew IRC-50S
3H1) ion-exchange resin, the resin ®ltered off, and washed
with MeOH. The resulting solution was concentrated under
vacuum giving 2-pyridyl b-d-galactopyranoside 7 36.3 g,
24.5 mmol, 95%) as a white foam: [a]Dˆ214 3c 1.0,
2.1.4. 2-Pyridyl 2,3,4,6-tetra-O-acetyl-b-d-galactopyra-
noside /5). To a suspension of 1,2,3,4,6-penta-O-acetyl-b-
d-galactopyranose 4 310 g, 25.63 mmol) in Ac2O 31.25 mL)
and AcOH 325 mL) was added HBr 330% in AcOH,
12.5 mL) dropwise. The reaction mixture was stirred for
2 h at room temperature, diluted with toluene 3250 mL),
washed with ice water 32£150 mL), cold saturated
NaHCO3 3100 mL), ice water 3100 mL) and concentrated.
The residue was redissolved in toluene, concentrated and
the residue dried by codistillation with dry toluene
32£75 mL). The residue was redissolved in dry toluene
380 mL) and silver 2-pyridoxide 35.95 g, 15% excess) was
added in one portion. The mixture was re¯uxed under vigor-
ous stirring for 1 h, allowed to cool down to room tempera-
ture, ®ltered through Celitew, and the bed was washed with
toluene 3150 mL). The ®ltrate was washed with saturated
NaHCO3 3100 mL); the heterogeneous mixture was ®ltered
through a Celitew pad, rinsed with toluene and both phases
separated. The organic phase was washed with water
3100 mL), dried 3Na2SO4), concentrated and puri®ed by
¯ash chromatography 3EtOAc/hexanes 1:1) giving 5
37.73 g, 18.17 mmol, 71% yield) as a white foam:
1
CH3OH). H NMR 3CD3OD, 400 MHz); d ppm: 8.16 3m,
1H, PyCH), 7.76 3m, 1H, PyCH), 7.06 3m, 1H, PyCH), 6.96
3m, 1H, PyCH), 5.63 3d, 1H, H-1, J1,2ˆ8.0 Hz), 3.94 3dd,
1H, H-4, J4.3ˆ3.3 Hz, J4,5ˆ0.0 Hz), 3.84 3dd, 1H, H-2,
J2,3ˆ9.8 Hz), 3.73±3.76 3m, 3H, H-5, H-6 and H-6A) and
3.62 3dd, 1H, H-3). 13C NMR 3CD3OD, 100 MHz); d ppm:
164.0 3PyC), 147.8, 141.1, 119.7, and 112.5 3PyCH), 98.9
3C-1), 77.0, 74.9, 71.9, 70.1 3C-2 to C-5), 62.3 [32), C-6].
HR-FABMS calcd for C11H16O6N m/z 258.0977; found
258.0967.
2.1.7. 3-Methoxy-2-pyridyl b-d-galactopyranoside /3).
Using the same procedure 7 34.01 g, 8.8 mmol) was
dissolved in MeOH 330 mL) and sodium methoxide 30.5N
in MeOH, 0.2 mL). Neutralization and concentration gave 3
32.37 g, 8.25 mmol, 94%) as a white foam: [a]Dˆ10.7 3c
1
0.7, CH3OH). H NMR 3CD3OD, 400 MHz); d ppm: 7.68
1
[a]Dˆ127 3c 1.0, CHCl3). H NMR 3CDCl3, 400 MHz);
3dd, 1H, Jˆ1.3, 4.9Hz), 7.10 3dd, 1H, Jˆ1.3, 7.9Hz), and
6.94 3dd, 1H, Jˆ4.9, 7.8 Hz) 3PyCH), 5.86 3d, 1H, H-1,
J1,2ˆ8.1 Hz), 3.93 3dd, 1H, H-4, J4,3ˆ3.2 Hz, J4,5ˆ
0.0 Hz), 3.90 3dd, 1H, H-2, J2,3ˆ9.5 Hz), 3.86 3m, 3H,
H-5, H-6 and H-6A), 3.72 3s, 3H, OCH3), 3.62 3dd, 1H,
H-3). 13C NMR 3CD3OD, 100 MHz); d ppm: 153.7 and
145.8 3PyC), 137.7, 120.5, and 119.7 3PyCH), 97.8 3C-1),
76.9, 75.0, 71.7, and 70.1 3C-2 to C-5), 62.2 [32), C-6], 56.3
3OCH3). HR-FABMS calcd for C12H18O7N m/z 288.1083;
found 288.1078.
d ppm: 8.13 31H), 7.61 31H), 6.97 31H) and 6.80 31H)
34m, PyH), 6.17 3d, 1H, H-1, J1,2ˆ8.3 Hz), 5.493dd, 1H,
H-2, J2,3ˆ10.4 Hz), 5.45 3dd, 1H, H-4, J4,3ˆ3.4 Hz,
J4,5ˆ0.0 Hz), 5.15 3dd, 1H, H-3), 4.13 3m, 3H, H-5, H-6
and H-6A), 2.15 3s, 3H), 1.99 3s, 6H) and 1.95 3s, 3H),
3COCH3). 13C NMR 3CDCl3, 100 MHz); d ppm: 170.2,
170.1, 169.9 and 169.4 3CO), 161.1 3PyC), 146.6, 139.2,
118.7, and 111.6 34PyCH), 93.7 3C-1), 70.9, 70.9, 68.3,
and 66.8 3C-2 to C-5), 60.8 [32), C-6], 20.5, 32C), 20.4
and 20.4 34COCH3). HR-FABMS calcd for C19H24O10N
m/z 426.1400; found 426.1417.
2.1.8. 2-Pyridyl 4-O-acetyl-2-O-benzoyl-6-O-tert-butyl-
diphenylsilyl-b-d-galactopyranoside /10a). 3a) Orthoester
approach. To a solution of 7 31.42 g, 5.52 mmol) in dry
DMF 320 mL) was added TBDPSCl 31.58 mL, 1.1 equiv.)
dropwise and the reaction mixture stirred for 5 h at room
temperature. The solution was diluted with EtOAc
3150 mL), extracted with H2O 32£100 mL), dried
3Na2SO4) and concentrated. The residue was puri®ed by
¯ash chromatography 3EtOAc/hexanes 1:2 then EtOAc)
affording 2-pyridyl 6-O-tert-butyldiphenylsilyl-b-d-galac-
topyranoside 32.21 g, 4.46 mmol, 81%) as a white foam:
HR-FABMS calcd for C27H34O6NSi m/z 496.2155; found
496.2126. A solution of the preceding compound 31.95 g,
3.93 mmol), triethyl orthoacetate 31.00 mL, 2 equiv.) and
pyridinium tri¯ate 32 mg) in CH2Cl2 335 mL) was stirred
at room temperature for 45 min. The reaction mixture was
quenched with DMAP 30.96 g, 7.88 mmol), the solvent
removed under vacuum, and the solid residue dried under
high vacuum 320 min at 408C bath temperature). The resi-
due was redissolved in CH2Cl2 317.5 mL), BzCl 30.55 mL,
20% excess) was added and the solution stirred for 1 h
30 min at room temperature. The excess BzCl was quenched
2.1.5. 3-Methoxy-2-pyridyl 2,3,4,6-tetra-O-acetyl-b-d-
galactopyranoside /6). Using the same procedure as
above, a solution of 4 34 g, 10.25 mmol), Ac2O 30.5 mL)
and AcOH 310 mL), and HBr 330% in AcOH, 5 mL)
afforded the corresponding bromide which was dissolved
in dry toluene 336 mL). Silver 3-methoxy-2-pyridoxide
32.8 g, 20% excess) was added in one portion, and the
system was re¯uxed under vigorous stirring for 1 h.
Work-up and puri®cation 3¯ash chromatography, EtOAc/
hexanes 1:1) gave 6 34.03 g, 8.85 mmol, 86% yield) as a
white foam: [a]Dˆ135.18 3c 1.1, CHCl3). 1H NMR
3CDCl3, 400 MHz); d ppm: 7.70 3dd, 1H, Jˆ1.3, 4.9Hz,
PyCH), 7.10 3dd, 1H, Jˆ1.3, 7.9Hz, PyCH), 6.94 3dd, 1H,
Jˆ4.9, 7.8 Hz, PyCH), 6.21 3d, 1H, H-1, J1,2ˆ8.3 Hz), 5.57
3dd, 1H, H-2, J2,3ˆ10.4 Hz), 5.45 3dd, 1H, H-4, J4,3ˆ3.3 Hz,
J4,5ˆ0.0 Hz), 5.16 3dd, 1H, H-3), 4.13 3m, 3H, H-5, H-6 and
H-6A), 3.82 3s, 3H, OCH3), 2.15 3s, 3H), 1.99 3s, 6H), and
1.95 3s, 3H) 3CH3CO). 13C NMR 3CDCl3, 100 MHz); d
ppm: 170.3, 170.2, 170.1 and 169.3 3CO), 151.5, and
144.1 3PyC), 136.6, 119.1, and 118.9 3PyCH), 93.8 3C-1),

S. Hanessian et al. / Tetrahedron 57 52001) 3267±3280
3273
by stirring the reaction mixture for 15 min after addition of
MeOH 30.5 mL). The solution was concentrated under
vacuum and the residue consisting of 8 was redissolved in
AcOH 390%, 20 mL). The solution was stirred for 15 min at
room temperature, diluted with CH2Cl2 3150 mL), washed
with ice water 3100 mL), cold saturated NaHCO3 solution
3100 mL), ice H2O 3100 mL), dried 3Na2SO4), ®ltered and
concentrated. The crude product was puri®ed by ¯ash chro-
matography 3EtOAc/hexanes 1:3) giving 10a 31.92 g,
2.99 mmol, 76%) as white foam: [a]Dˆ214.4 3c 1.1,
2 equiv.) was added; the solid residue obtained after
evaporation was dissolved in CH2Cl2 31.3 mL) and the solu-
tion stirred for 1 h at room temperature after addition of
BzCl 338 mL). The excess BzCl was quenched by addition
of methanol and the crude product obtained after work-up
consisting of 9 was treated with a solution of AcOH, AcONa
and water 390% aq. AcOH1AcONa until pH ,4, 2 mL).
The solution was stirred at room temperature until no more
starting material was detected by TLC 3,2 h). Work-up and
puri®cation 3¯ash chromatography with pure EtOAc)
afforded 11a 3122.9mg, 0.183 mmol, 67%) as white
foam: [a]Dˆ27.93 c 1.1, CHCl3). 1H NMR 3CDCl3,
300 MHz); d ppm: 7.98 32H), 7.65 34H), 7.52 31H), and
7.46±7.32 38H) 34m, 15H, 15PhCH), 7.72 31H), 7.02
31H), and 6.90 31H) 33m, 3H, PyCH), 6.44 3d, 1H, H-1,
J1,2ˆ8.2 Hz), 5.66 3dd, 1H, H-4, J4,3ˆ3.4 Hz,
J4,5ˆ0.0 Hz), 5.593dd, 1H, H-2, J2,3ˆ9.9 Hz), 4.20 3ddd,
1H, J3,OHˆ3.0 Hz, H-3), 4.04 3ddd, 1H, H-5, J5,6ˆ4.1 Hz,
J5,6Aˆ6.4 Hz), 3.88±3.72 3m, 2H, H-6, and H-6A), 3.70 3s,
3H, OCH3), 3.06 3d, 1H, OH), 2.10 3s, 3H, COCH3), 1.03 3s,
9H, SiC3CH3)3). 13C NMR 3CDCl3, 100 MHz); d ppm:
171.0 and 166.6 3CO), 151.8 and 144.1 3PyC), 132.9,
129.4, and 128.4 3PhC), 136.5, 119.0, and 118.7 3PyCH),
135.5, 133.1, 129.8, 129.7, 129.6, 128.1, 127.6, and 127.5
3PhCH), 93.7 3C-1), 74.0, 73.3, 72.0, and 69.5 3C-2 to C-5),
61.2 [32), C-6], 55.6 3OCH3), 20.7 3COCH3), 26.6 and 18.9
3q) 3SiC3CH3)3). HR-FABMS calcd for C37H42O9NSi m/z
672. 2628; found 672.2623.
1
CHCl3). H NMR 3CDCl3, 300 MHz); d ppm: 8.15 31H),
6.92 31H) and 6.74 31H) 3m, 3PyH), 7.98 32H), 7.62±7.58
34H), 7.58±7.48 32H), 7.42±7.30 38H), 3m, 15PhCH and
1PyH), 6.36 3d, 1H, H-1, J1,2ˆ8.3 Hz), 5.64 3dd, 1H, H-4,
J4,3ˆ3.5 Hz, J4,5ˆ0.7 Hz), 5.54 3dd, 1H, H-2, J2,3ˆ10.0 Hz),
4.20 3dd, 1H, H-3), 4.05 3ddd, 1H, H-5, J5,6ˆ6.0 Hz,
J5,6Aˆ7.6 Hz), 3.78 3dd, 1H, H-6, J6,6Aˆ10.0 Hz), 3.73
3dd, 1H, H-6A), 2.10 3s, 3H, COCH3), 1.03 3s, 9H,
SiC3CH3)3). 13C NMR 3CDCl3, 100 MHz); d ppm: 171.1
and 166.7 3CO), 161.5 3PyC), 133.0, 132.9, and 129.4
3PhC), 135.6, 133.3, 129.9, 129.8, 129.7, 128.3, 127.7,
and 127.7 3PhCH), 146.6, 139.3, 118.6, and 111.9
3PyCH), 93.7 3C-1), 74.1, 73.0, 72.0, and 69.8 3C-2 to
C-5), 61.5 [32), C-6], 20.8 3COCH3), 26.7 and 19.1 3q)
3SiC3CH3)3). FABMS 3rel. intensity) 642.4 329), [M1H]1.
HR-FABMS calcd for C36H40O8NSi m/z 642.2523; found
642.2513.
3b) Orthoamide approach. To a solution of 7 3317 mg,
0.632 mmol) in dry CH2Cl2 39mL) was added N,N-
dimethylacetamide dimethyl acetal 30.11 mL, 20% excess)
under nitrogen and the reaction mixture was stirred for
15 min at room temperature. The solvent was removed
under vacuum and the residue concentrated under high
vacuum 320 min, 408C bath temperature). To a solution of
the crude product in dry CH2Cl2 36 mL) was added a solu-
tion of dry DMAP 3154.4 mg, 2 equiv.) in CH2Cl2 33 mL)
via cannula followed by benzoyl chloride 30.077 mL, 5%
excess). The reaction mixture was stirred under nitrogen for
2 h at room temperature, diluted with CH2Cl2 330 mL),
washed with water 320 mL), dried 3Na2SO4), and concen-
trated. The crude product was dissolved in AcOH 390% aq.,
5 mL) and stirred for 15 min at room temperature. The solu-
tion was diluted with CH2Cl2 350 mL), washed with ice
water 330 mL), cold saturated NaHCO3 330 mL), ice water
330 mL), dried 3Na2SO4) and concentrated. The crude
product was puri®ed by ¯ash chromatography 3EtOAc/
hexanes 1:3, two columns were necessary) affording pure
10a 3228 mg, 0.35 mmol, 55%) and the corresponding 3-
acetate 368 mg, 0.11 mmol, 17%), both as white foams.
2.1.10. 2-Pyridyl 4-O-acetyl-2,6-di-O-benzoyl-6-O-tert-
butyldiphenylsilyl-b-d-galacto-pyranoside /10b). A solu-
tion of 8 31.50 g, 3.03 mmol), triethyl orthoacetate
30.73 mL, 1.3 equiv.) and pyridinium tri¯ate 31 mg) in
CH2Cl2 330.3 mL) was stirred at room temperature for
45 min. After the addition of one drop of Et3N and stirring
the solution for 5 min at room temperature, the reaction
mixture was concentrated to dryness under vacuum. The
residue was dissolved in THF 33 mL), TBAF 33.3 mL,
1.1 equiv.) was added and the solution stirred for 2 h at
room temperature. The reaction mixture was diluted with
CH2Cl2 3100 mL), extracted with water, dried 3Na2SO4) and
concentrated. To the solution of the crude product in CH2Cl2
315.2 mL), DMAP 33.3 g, 1.2 equiv.) and benzoyl chloride
30.772 mL, 1.1 equiv.) were added and the mixture was
stirred for 1 h 30 min at room temperature. Excess BzCl
was quenched by addition of MeOH 30.5 mL) and stirring
for 15 min. The solution was concentrated under vacuum,
the residue dissolved in AcOH 390%, 20 mL), and stirred for
15 min at room temperature. The reaction mixture was
diluted with CH2Cl2 3150 mL), washed with ice water
3100 mL), cold saturated NaHCO3 3100 mL), ice water
3100 mL), dried 3Na2SO4), ®ltered and concentrated. The
crude was puri®ed by ¯ash chromatography 3EtOAc/
hexanes 1:2) to give 10b 30.84 g, 1.66 mmol, 55%) as a
white foam: [a]Dˆ118.6 3c 1.1, CHCl3). 1H NMR
3CDCl3, 300 MHz); d ppm: 8.10 31H), 6.92 31H), and
6.78 31H) 33m, 3PyCH), 8.01 34H), 7.55 33H), and 7.44
34H) 33m, 10PhCH and 1PyCH), 6.393d, 1H, H-1,
J1,2ˆ8.3 Hz), 5.64 3dd, 1H, H-2, J2,3ˆ10.0 Hz), 5.61 3dd,
1H, H-4, J4,3ˆ3.4 Hz, J4,5ˆ0.0 Hz), 4.50 3dd, 1H, H-6,
J6,5ˆ7.1 Hz, J6,6Aˆ11.1 Hz), 4.40 3dd, 1H, H-6A,
J6A,5ˆ6.3 Hz), 4.30 3dd, 1H, H-5), 4.21 3dd, 1H, H-3),
3.44 3br, 1H, OH), 2.24 3s, 3H, COCH3). 13C NMR
2.1.9. 3-Methoxy-2-pyridyl 4-O-acetyl-2-O-benzoyl-6-O-
tert-butyldiphenylsilyl-b-d-galactopyranoside /11a). A
solution of 3 32 g, 6.69mmol) and TBDPSCl 31.9mL,
1.1 equiv.) in DMF 324 mL) was stirred at room temperature
for 5 h to afford after work-up and puri®cation 3-methoxy-
2-pyridyl 6-O-tert-butyldiphenylsilyl-b-d-galactopyrano-
side 32.75 g, 5.23 mmol, 78%) as a white foam: HR-
FABMS calcd for C28H36O7NSi m/z 526.2261; found
526.2286. The preceding compound 3142.5 mg,
0.271 mmol), triethyl orthoacetate 399 mmL) and pyridi-
nium tri¯ate 31 mg), in CH2Cl2 32.5 mL), was stirred at
room temperature for 1 h 15 min, and DMAP 366 mg,

3274
S. Hanessian et al. / Tetrahedron 57 52001) 3267±3280
3CDCl3, 100 MHz); d ppm: 170.8, 166.7 and 165.93CO),
161.3 3PyC), 129.4 and 129.1 32PhC), 146.5, 139.1, 118.5,
and 111.7 34PyCH), 133.3, 133.0, 129.8, 129.6, 128.2 32C)
3PhCH), 93.6 3C-1), 72.8, 71.6, 71.4, and 69.7 3C-2 to C-5),
61.8 [32), C-6], 20.7 33COCH3). HR-FABMS calcd for
C27H26O9N m/z 508.1607; found 508.1619.
washed with water 375 mL), 1N HCl 375 mL), water
375 mL), dried 3Na2SO4) and concentrated. The crude was
puri®ed by ¯ash chromatography 3EtOAc/hexanes 1:2)
giving 12a 31.95 g, 2.44 mmol, 82%) as a white foam.
b. Using TMS tri¯ate as activator: To a solution of 11a 31 g,
1.49mmol) and 6-benzyloxycarbonylamino-1-hexanol
3411 mg, 1.1 equiv.) in CH2Cl2 329.8 mL) was added
TMSTf 3285 mL mg, 1.1 equiv.) in one portion and the
mixture stirred for 1 h at room temperature. The reaction
mixture was diluted with CH2Cl2 3150 mL), washed with
water 350 mL), 1N HCl 350 mL), water 350 mL), dried
3Na2SO4) and concentrated. The crude was puri®ed by
¯ash chromatography 3EtOAc/hexanes 1:2) giving 12a
30.94 mg, 1.17 mmol, 78%) as a white foam.
2.1.11. 3-Methoxy-2-pyridyl 4-O-acetyl-2,6-di-O-benz-
oyl-6-O-tert-butyldiphenylsilyl-b-d-galactopyranoside
/11b). A solution of 9 31.90 g, 3.03 mmol), triethyl ortho-
acetate 30.73 mL, 1.3 equiv.) and pyridinium tri¯ate 31 mg)
in CH2Cl2 330.3 mL) was stirred for 45 min. The mixture
was treated with Et3N 31 drop) and worked-up as described
above. The solid residue was redissolved in THF 32.1 mL),
TBAF 32.09mL, 1.1 equiv.) was added and the mixture was
stirred for 2 h at room temperature and worked-up as usual.
The crude product was treated with DMAP 30.557 g,
1.2 equiv.) and BzCl 3485 mL, 1.1 equiv) in CH2Cl2
39.5 mL) for 3 h at room temperature and the reaction
mixture worked-up as before. The crude product was
dissolved in 15 mL of buffered AcOH 390% AcOH1A-
cONa, pH ,4, 10 mL) and stirred at room temperature
until TLC indicated the completeness of the reaction,
,1 h. After the same work-up described for 10b, the
crude was puri®ed by ¯ash chromatography 3EtOAc/
hexanes 2:3) giving 11b 30.61 g, 1.66 mmol, 60%) as
white foam: [a]Dˆ116.1 3c 1.0, CHCl3). 1H NMR
3CDCl3, 300 MHz); d ppm: 8.00 34H), 7.55 32H), and
7.41 34H) 33m, 10H, PhCH), 7.70 31H), 7.04 31H), and
6.92 31H) 33m, 3H, PyCH), 6.47 3d, 1H, H-1,
J1,2ˆ8.2 Hz), 5.65 3dd, 1H, H-2, J2,3ˆ9.8 Hz), 5.60 3dd,
1H, H-4, J4,3ˆ3.2 Hz, J4,5ˆ0.0 Hz), 4.51 3dd, 1H, H-6,
J6,5ˆ6.9Hz, J6,6Aˆ11.2 Hz), 4.393dd, 1H, H-6A,
J6A,5ˆ6.5 Hz), 4.293dd, 1H, 3H), 4.20 3ddd, 1H, H-3,
J3,OHˆ6.2 Hz), 3.71 3s, 3H, OCH3), 3.25 3d, 1H, OH), 2.25
3s, 3H, COCH3). 13C NMR 3CDCl3, 100 MHz); d ppm:
170.9, 166.9 and 166.0 3CO), 151.7 and 144.2 3PyC),
129.5 and 129.3 3PhC), 136.6, 119.1, and 118.9 3PyCH),
133.3, 133.1, 129.9, 129.7, 128.3, and 128.3 3PhCH), 93.7
3C-1), 73.2, 72.0, 71.6, and 69.7 3C-2 to C-5), 62.0 [32),
C-6], 55.7 3OCH3), 20.8 3COCH3). HR-FABMS calcd for
C28H28O10N m/z 538.1713; found 538.1724.
c. Using Cu3TfO)2 as activator: To a solution of 11a
355.0 mg, 0.082 mmol) and 6-benzyloxycarbonylamino-1-
hexanol 330.5 mg, 1.5 equiv.) in CH2Cl2 32 mL) containing
molecular sieves 320 mg) was added Cu3TfO)2 343.9mg,
1.5 equiv.) in one portion and the mixture stirred for 6 h at
room temperature. The reaction mixture was quenched with
a drop of pyridine, diluted with CH2Cl2 320 mL) and ®ltered
through a Celitew pad. The solution was washed with water
315 mL), 1N HCl 315 mL), water 315 mL), dried 3Na2SO4)
and concentrated. The crude product was puri®ed by ¯ash
chromatography 3EtOAc/hexanes 1:2) giving 12a 343 mg,
0.053 mmol, 65%) as a white foam: [a]Dˆ228.5 3c 1.1,
1
CHCl3). H NMR 3CDCl3, 300 MHz); d ppm: 8.06 32H),
7.66 34H), 7.56 31H), 7.48±7.31 313H), 34m, 20H, PhCH),
5.56 3dd, 1H, H-4, J4,3ˆ3.5 Hz, J4,5ˆ0.0 Hz), 5.24 3dd, 1H,
H-2, J2,1ˆ7.9Hz, J2,3ˆ 10.0 Hz), 5.093s, 2H, CH 2Ph), 4.62
3m, 1H, NHCbz), 4.56 3d, 1H, H-1), 4.03 3dd, 1H, H-3), 3.87
31H) and 3.43 31H) 32 m, OCH2R), 3.78 3m, 3H, H-5, H-6
and H-6A), 3.01 3m, 3H, 2NCH2R), 2.78 3br, 1H, OH), 2.08
3s, 3H, COCH3), 1.48 32H) and 1.16 36H) 32 m, ±CH2±),
1.08 3s, 9H, SiC3CH3)3). 13C NMR 3CDCl3, 100 MHz); d
ppm: 171.1 and 166.5 3CO), 133.1, 132.9, 128.0 and 129.7
3PhC), 135.6, 135.5, 133.2, 129.8, 129.8, 128.4, 128.3,
127.7, and 127.7 3PhCH), 101.1 3C-1), 73.6 32C), 71.8 and
69.7 3C-2 to C-5), 69.8, 66.5, and 61.6 [32), OCH2R,
CH2Ph, and C-6], 40.8 [32), NHCH2R], 29.6, 29.2, 26.2,
and 25.5 [32), ±CH2±], 20.7 3COCH3), 26.7 and 19.1 3q)
3SiC3CH3)3). HR-FABMS calcd for C45H56O10NSi m/z
798.3673; found 798.3689.
2.1.12. 6-Benzyloxycarbonylamino-1-hexanyl 4-O-ace-
tyl-2-O-benzoyl-6-O-tert-butyldiphenylsilyl-b-d-galacto-
pyranoside /12a). A. From 10a using HBF4´Et2O as
activator. To a solution of 10a 30.96 g, 1.5 mmol) and
6-benzyloxycarbonylamino-1-hexanol 30.45 g, 1.2 equiv.)
in CH2Cl2 321.4 mL) was added HBF4´Et2O 358% in Et2O,
184 mL, 1.1 equiv.) in one portion and the mixture was
stirred for 1 h at room temperature. The reaction mixture
was diluted with CH2Cl2 3150 mL), washed with water
375 mL), 1N HCl 375 mL), water 375 mL), dried 3Na2SO4)
and concentrated. The crude product was puri®ed by ¯ash
chromatography 3EtOAc/hexanes 1:2) giving 12a 30.96 g,
1.2 mmol, 80%) as a white foam.
2.1.13. 6-Benzyloxycarbonylamino-1-hexanyl 4-O-ace-
tyl-2,6-di-O-benzoyl-b-d-galactopyranoside /12b) from
11b using HBF4´Et2O as activator. Adopting the same
procedure as described for 11a but using 11b 30.301 g,
0.56 mmol) and 6-benzyloxycarbonylamino-hexanol 30.189
g, 1.2 equiv.) in CH2Cl2 38 mL) and HBF4´Et2O 358% in
Et2O, 54.4 mL, 1.1 equiv.) afforded after ¯ash chromato-
graphy 3EtOAc/hexanes 1:1) 12b 30.267 g, 0.40 mmol,
72%) as syrup: [a]Dˆ212.0 3c 1.1, CHCl3). 1H NMR
3CDCl3, 300 MHz); d ppm: 8.04 34H), 7.58 32H), 7.46
34H), 7.35 35H), 34m, 15H, PhCH), 5.53 3dd, 1H, H-4,
J3,4ˆ3.0 Hz, J4,5ˆ0.6 Hz), 5.31 3dd, 1H, H-2, J2,1ˆ7.9Hz,
J2,3ˆ10.0 Hz), 5.08 3s, 2H, CH2Ph), 4.70 3m, 1H, NHCbz),
4.61 3d, 1H, H-1), 4.55 3dd, 1H, H-6, J6,5ˆ6.9Hz,
J6,6Aˆ11.3 Hz), 4.36 3dd, 1H, H-6A, J6A,5ˆ6.6 Hz), 4.01
3m, 2H, H-3, H-5), 3.90 31H) and 3.47 31H) 32m, 2H,
2OCH2R), 3.18 3br, 1H, OH), 2.18 3m, 2H, NHCH2R),
B. From 11a. a. Using HBF4´Et2O as activator: To a solution
of 11a 32.0 g, 2.98 mmol) and 6-benzyloxycarbonylamino-
1-hexanol 31.12 g, 1.2 equiv.) in CH2Cl2 360 mL) was added
HBF4´Et2O 358% in Et2O, 365 mL, 1.1 equiv.) in one portion
and the mixture stirred for 1 h at room temperature. The
reaction mixture was diluted with CH2Cl2 3150 mL),

S. Hanessian et al. / Tetrahedron 57 52001) 3267±3280
3275
2.00 3s, 3H, COCH3), 1.50 31H) and 1.18 31H) 3m, 2H, 8 ±
CH2±). 13C NMR 3CDCl3, 100 MHz); d ppm: 171.0, 166.5,
166.1, and 156.3 3CO), 136.0 and 128.6 32C) 33PhC), 133.3,
133.3, 129.8, 129.7, 129.5, 128.4, 128.4 and 128.0 3PhCH),
101.3 3C-1), 73.4, 71.3, 71.0 and 69.9 3C-2 to C-5), 70.1,
66.5 and 62.1 [32), C-6, OCH2R and CH2Ph], 40.8 [32),
NHCH2R], 29.6, 29.2, 26.2, and 25.4 [32), 4 ±CH2±], 20.8
3COCH3). HR-FABMS calcd for C36H42O11N m/z 664.2757;
found 664.2770.
was dissolved in dry toluene 37.6 mL) and Cu3TfO)2
3192 mg, 1.0 equiv. dried at 2008C for 2 h under vacuum
just before use) was added quickly and the mixture stirred
for one day at room temperature under argon. The same
work-up as described above afforded 14a 3424.3 g,
0.321 mmol, 60%) as a white foam: [a]Dˆ134.5 3c 1.1,
CHCl3). 1H NMR 3CDCl3, 300 MHz, assigned by
COSY45); d ppm: 8.03 32H), 7.66 34H), 7.5±7.20 332H),
and 7.15 32H) 34m, 40H, PhH), 5.67 3dd, 1H, H-4,
J4,3ˆ3.1 Hz, J4,5ˆ0.0 Hz), 5.48 3dd, 1H, H-2, J2,1ˆ8.0 Hz,
J2,3ˆ10.2 Hz), 5.31 3d, 1H, H-10, J1 ,2 ˆ4.0 Hz), 4.43 3d, 1H,
H-2), 5.1 3s, 2H), 4.79±4.54 3m, 6H) and 4.42±4.30 3m, 3H)
35 CH2Ph and NHCbz), 4.12 3dd, 1H, H-3), 3.95 32H), 3.80±
3.62 33H), 3.62±3.48 32H) and 3.28±3.20 32H) 34m, 9H, H-
5, H-6, H-6A, H-20, H-30, H-40, H-50, H-60 and H-6A0), 3.84
0
0
2.1.14. 3-Methoxy-2-pyridyl 2,3,4,6-tetra-O-benzyl-b-d-
galactopyranoside /13). To a solution of 3 32 g, 6.97 mmol)
in dry DMF 369.7 mL) was added NaH 31.4, 60% in mineral
oil, washed with hexanes) at 08C; the mixture was stirred
until no more gas evolved, ,1 h. At the same temperature
was added dropwise BnBr 34.01 mL, 1.25 equiv.) and the
mixture stirred for 1 h. The reaction mixture was allowed to
warm up to room temperature then stirred overnight. The
excess BnBr was quenched by adding MeOH then diluted
with EtOAc 3250 mL), extracted with water 32£150 mL)
and brine 350 mL), dried 3Na2SO4), concentrated, and puri-
®ed by ¯ash chromatography 3EtOAc/hexanes 1:3) giving
13 as a syrup: [a]Dˆ129.9 3c 1.0, CHCl3). 1H NMR
3CDCl3, 300 MHz); d ppm: 7.78 31H), 7.12 31H), and
6.96 31H) 33m, PyH), 7.48±7.22 3m, 20PhCH), 6.13 3d,
1H, H-1, J1,2ˆ8.0 Hz), 5.05 and 4.83 3AB, 2H,
Jˆ11.6 Hz), 5.01 and 4.68 3AB, 2H, Jˆ11.4 Hz), 4.83
3narrow AB, 2H), 4.52 and 4.45 3AB, 2H, Jˆ11.7 Hz)
38CH2Ph), 4.27 3dd, 1H, H-2, J2,3ˆ9.7 Hz), 4.07 3dd, 1H,
H-4, J4,3ˆ2.9Hz, J4,5ˆ0.0 Hz), 3.90 3ddd, 1H, H-5,
J5,6ˆ5.8 Hz, J5,6Aˆ6.8 Hz), 3.85 3s, 3H, OCH3), 3.79±3.66
3m, 3H, H-3, H-6 and H-60). 13C NMR 3CDCl3, 100 MHz); d
ppm: 149.93 and 141.70 3PyC), 136.3, 136.2, 136.0, and
135.4 3PhC), 134.4, 115.4, and 115.7 3PyCH), 125.8,
125.6, 125.5, 125.5, 125.4, 125.2, 125.0, 124.9, 124.8, and
124.4 3PhCH), 94.1 3C-1), 79.7, 76.4, 71.3, and 71.1 3C-2 to
C-5), 72.6, 72.1, 70.9and 70.4 [3 2), 4CH2Ph], 62.7 [32), C-
6], 53.1 3OCH3). HR-FABMS calcd for C40H42O7N m/z
648.2961; found 648.2976.
31H) and 3.3931H) 32 m, OCH R), 2.98 3m, 2H, NCH2R),
2
1.78 3s, 3H, COCH3), 1.48 32H) and 1.16 36H) 32 m, ±CH2±),
1.08 3s, 9H, SiC3CH3)3). 13C NMR 3CDCl3, 100 MHz); d
ppm: 170.11, 164.8 and 156.3 3CO), 138.8 33C), 138.4 32C),
136.7, 133.2 and 133.1 38PhC), 135.6, 135.6, 133.1, 129.8,
129.7, 128.5, 128.4, 128.3, 128.2, 128.0, 127.9, 127.7,
127.7, 127.9, 127.4, 127.3, and 127.2 3PhCH), 101.6 3C-
1), 93.2 3C-10), 78.8, 77.3, 75.8, 75.0, 71.6, 71.0, 73.9and
64.7 3C-2 to C-5 and C-20 to C-50) 74.5, 73.4, 73.3, 73.1,
69.8 32C), 66.5 and 61.8 [all 32), C-6, C-60, OCH2R and
5CH2Ph], 40.8 [32), NHCH2R], 29.6, 29.2, 26.2, and 25.5
[all 32), 4-CH2±], 20.52 3COCH3), 26.8 and 19.1 3q)
3SiC3CH3)3). FABMS 3rel. intensity) 1320.3 32), [M]1.
Anal. Calcd for C79H89NO15Si: C, 71.85; H, 6.79; N, 1.06.
Found: C, 71.82; H, 6.67; N, 1.1.
2.1.16. 6-Benzyloxycarbonylamino-1-hexanyl O-/2,3,4,6-
tetra-O-benzyl-a-d-galactopyranosyl)-/1!3)-4-O-ace-
tyl-2,6-di-O-benzoyl-b-d-galactopyranoside /14b). Using
Cu3TfO)2 as activator applying the same procedure as
described for 14a but using: 12b 3150 mg, 0.226 mmol)
and 13 3146 mg, 1.0 equiv.), and Cu3TfO)2 381.0 mg,
1.0 equiv.) in toluene 35.3 mL) and stirring the reaction
mixture for two days at room temperature gave after ¯ash
chromatography 3EtOAc/hexanes 1:2, two columns were
necessary) 14b 3178 mg, 0.116 mmol, 51%) as a white
foam: [a]Dˆ136.2 3c 1.1, CHCl3). 1H NMR 3CDCl3,
300 MHz); d ppm: 8.05 34H), 7.60 31H), 7.48 33H), 7.40±
7.18 325H), and 7.15 32H) 3m, 35H, PhH), 5.66 3d, 1H, H-4,
J4,3ˆ3.0 Hz, J4,5ˆ0.0 Hz), 5.54 3dd, 1H, H-2, J2,1ˆ8.0 Hz,
2.1.15. 6-Benzyloxycarbonylamino-1-hexanyl O-/2,3,4,6-
tetra-O-benzyl-a-d-galactopyranosyl)-/1!3)-4-O-acetyl-
2-O-benzoyl-6-O-tert-butyldiphenylsilyl-b-d-galacto-
pyranoside /14a). 3a) Using Yb3TFO)3 as activator. A
10 mL round bottom ¯ask containing a mixture of 12a
3150 mg, 0.188 mmol) and 13 3121 mg, 1.0 equiv.), and a
magnetic stirrer were dried overnight under vacuum over
P2O5. The mixture was dissolved in dry CH2Cl2 32.7 mL)
and Yb3TfO)3 3117 mg, 1.0 equiv. dried at 2008C 2 h under
vacuum just before use) was added quickly and the mixture
stirred for 2 h at room temperature under argon. A second
portion of 13 324.3 mg, 0.2 equiv.) was added and the
mixture stirred at room temperature for 2 h. The reaction
mixture was diluted with CH2Cl2 350 mL), washed with
water 320 mL), 1N HCl 320 mL), water 320 mL), dried
3Na2SO4) and concentrated. Puri®cation 3¯ash chromato-
graphy, EtOAc/hexanes 1:3) afforded pure 14a 3189mg,
0.143 mmol, 76%) as a white foam.
J2,3ˆ10.2 Hz), 5.23 3d, 1H, H-10, J1 ,2 ˆ3.4 Hz), 5.1 3s, 2H),
4.77 3d, 1H, Jˆ11.5 Hz), and 4.69±4.28 3m, 11H) 35CH2Ph,
H-1A, NHCbz, H-6, and H-6A), 4.14 3dd, 1H, H-3), 3.97±
3.85 3m, 4H), 3.61 3dd, 1H, Jˆ2.7, 10.1 Hz), 3.50±3.43 3m,
0
0
0
2H), and 3.27±3.193m, 2H) 34m, 9H, H-5, H-2 , H-30, H-40,
H-50, H-60, H-6A0, and 2OCH2R), 3.01±2.98 3m, 2H,
NCH2R), 1.90 3s, 3H, COCH3), 1.48 32H) and 1.16 36H)
32 m, ±CH2±). 13C NMR 3CDCl3, 100 MHz); d ppm:
170.4, 166.0, 164.7 and 156.3 34CO), 138.6, 138.3, 133.2,
133.1, 129.7, 128.4, 128.3, 128.2, 128.1, 127.8, 127.5,
127.5, and 127.4 3PhC and PhCH), 101. 7 3C-1), 98.5
3C-10), 78.7, 75.6, 74.9, 71.5, 71.0, 70.7, 69.8, and 64.8,
3C-2 to C-5 and C-20 to C-50), 74.4, 73.3, 73.2, 70.0, 69.6,
66.5, and 62.1 [all 32), C-6, C-60, 2 OCH2R and 5 CH2Ph],
40.8 [32), NHCH2R], 29.6, 29.2, 26.2, and 25.4 [all 32), 4
±CH2±], 20.50 3COCH3). FABMS 3rel intensity) 1186.7
35), [M]1. Anal. Calcd for C70H75O16N: C, 70.87; H, 6.37;
N, 1.18. Found: C, 69.61; H, 6.46; N, 1.21.
3b) Using Cu3TFO)2 as activator. A 10 mL round bottom
¯ask containing a mixture of 12a 3423.9mg, 0.531 mmol)
and 13 3344 mg, 1.0 equiv.), and a magnetic stirrer was
dried overnight under vacuum over P2O5. The mixture

3276
S. Hanessian et al. / Tetrahedron 57 52001) 3267±3280
2.1.17. 6-Amino-1-hexanyl O-/a-d-galactopyranosyl)-b-
d-galactopyranoside hydrochloride /15). To a solution of
14a 372.5 mg, 0.0549mmol) in dry MeOH 32 mL) was
added sodium methoxide 30.5 M in MeOH, 100 mL) and
the reaction mixture stirred for 48 h at room temperature.
The solution was concentrated under vacuum, the residue
dissolved in CH2Cl2 330 mL), washed with water, dried and
concentrated. To a solution of the crude product in THF
30.6 mL) was added in one portion TBAF 360 mL,
1.1 equiv.). The solution was stirred for 6 h at room tempera-
ture, concentrated and puri®ed by ¯ash chromatography
3CH2Cl2/MeOH 15:1) affording 6-benzyloxycarbonyl-
amino-1-hexanyl 3-O-32,3,4,6-tetra-O-benzyl-a-d-galacto-
pyranosyl)-b-d-galactopyranoside 333 mg, 0.035 mmol,
65%) as a syrup: FABMS 3rel intensity) 936.4 31.0),
[M]1. To a solution of the preceeding compound in dioxane/
water 32:1, 5 mL) was added 20% palladium-on-carbon
3Pearlman's catalyst, ,20 mg). The mixture was stirred
for 2 h under hydrogen 360 psi) at room temperature, the
hydrogen pressure was relieved, HCl 31N in dioxane,
,1 equiv.) was added and the mixture stirred under hydro-
gen 360 psi) overnight. The suspension was ®ltered through
a Celitew pad, and the pad rinsed with water 320 mL). The
®ltrate was concentrated under vacuum to about 5 mL, the
solution was passed through an ion exchange resin column
3Dowexw 1£8±50 in the chloride form), the column was
rinsed with water and lyophilized to give pure 15
317.3 mg, 0.039mmol, 95%; overall yield from 14a, 62%)
giving 17 31.58 g, 2.9mmol) as a white foam: [ a]Dˆ173
1
3c 1.0, CHCl3). H NMR 3CDCl3, 400 MHz, assigned by
COSY45); d ppm: 7.78 32H) and 7.67 32H) 32m, ArCH),
7.55 3dd, 1H, Jˆ1.5, 4.9Hz), 6.95 3dd, 1H, Jˆ1.5, 7.9Hz),
and 6.793dd, 1H, Jˆ4.9, 7.8 Hz) 3PyCH), 6.91 3d, 1H, H-1,
J1,2ˆ8.8 Hz), 5.96 3dd, 1H, H-3, J3,2ˆ10.6 Hz, J3,4ˆ9.1 Hz),
5.24 3dd, 1H, H-4, J4,5ˆ10.0 Hz), 4.68 3dd, 1H, H-2), 4.31
3dd, 1H, H-6, J6,5ˆ4.4 Hz, J6,6Aˆ12.4 Hz), 4.13 3dd, 1H,
H-6A, J6A,5ˆ2.2 Hz), 4.08 3ddd, 1H, H-5), 3.62 3s, 3H,
OCH3), 2.08, 2.06, and 1.85 3s, 9H, COCH3). 13C NMR
3CDCl3, 100 MHz); d ppm: 170.7, 170.1, 169.5, and 167.5
3CO), 151.4 and 144.0 3PyC), 131.4 3ArC), 136.9, 119.1,
and 119.0 3PyCH), 134.4, 134.1, 123.7, and 123.5 3ArCH),
91.8 3C-1), 72.1, 70.8, 78.74, 55.6, and 54.1 3C-2 to C-5,
OCH3), 61.8 [32), C-6], 20.7, 20.6, and 20.4 3COCH3). HR-
FABMS calcd for C26H27O11N2 m/z 543.1615; found
543.1666.
2.1.19. 3-Benzyloxycarbonylamino-1-propyl 3,4,6-tri-O-
acetyl-2-deoxy-2-phthalimido-b-d-glucopyranoside /18).
To a solution of 17 30.5 g, 0.92 mmol) and 3-benzyloxy-
carbonylamino-1-propanol 30.289g, 1.5 equiv.) in CH 2Cl2
313.1 mL) was added HBF4´Et2O 358% in Et2O, 90 mL,
1.1 equiv.) in one portion and the mixture was stirred for
12 h at room temperature. The reaction mixture was diluted
with CH2Cl2 3150 mL), washed with water 375 mL), 1N HCl
375 mL), water 375 mL), dried 3Na2SO4) and concentrated.
The crude product was puri®ed by ¯ash chromatography
3EtOAc/hexanes 1:1) giving 18 3375.4 mg, 0.6 mmol,
1
as a white powder: [a]Dˆ176.2 3c 0.5, DMSO). H NMR
1
3D2O, CH3OD internal standard at dˆ3.35 ppm, 300 MHz);
65%) as a white foam: [a]Dˆ118.1 3c 1.1, CHCl3). H
d ppm: 5.15 3d, 1H, H-10, J1 ,2 ˆ3.7 Hz), 4.46 3d, 1H, H-1,
J1,2ˆ7.9Hz), 4.02±3.60 3m, 12H, H-2 to H-6 and H-6A,
H-10 to H-60 and H-6A0, and 2OCH2R), 3.00 3m, 2H,
NCH2R), 1.64 34H) and 1.40 34H) 32 m, 8H, ±CH2±). 13C
NMR 3D2O, CH3OD internal standard at dˆ49.6 ppm,
100 MHz); d ppm: 103.2 3C-10), 95.9 3C-1), 78.0, 75.5,
71.5, 69.9 32C), 69.8, 68.9, 65.5 3C-2 to C-5 and C-20 to
C-50), 71.0 and 61.6 32C) [32), C-6, C-60, and OCH2R], 40.1
[32), NHCH2R], 29.1, 27.3, 26.0, and 25.2 [32), 4 ±CH2±].
FABMS 3rel. intensity) 442.2 311), [M2Cl]1. HR-FABMS
calcd for C18H36O11N m/z 442.2288; found 442.2275.
NMR 3CDCl3, 400 MHz, assigned by COSY45); d ppm:
7.82 32H) and 7.72 32H) 3m, ArCH), 7.34 3m, 5H, PhCH),
5.76 3dd, 1H, H-3, J3,2ˆ10.6 Hz, J3,4ˆ9.2 Hz), 5.38 3d, 1H,
H-1, J1,2ˆ8.5 Hz), 5.16 3d, 1H, H-4, J4,5ˆ9.9 Hz), 4.99 3m,
3H, CH2Ph and NHCbz), 4.293dd, 1H, H-6, J6,5ˆ4.4 Hz,
J6,6Aˆ12.3 Hz), 4.31 3dd, 1H, H-2), 4.193dd, 1H, H-6A,
J6A,5ˆ1.9Hz), 3.85 3m, 2H, H-5, OCH 2R), 3.56 3m, 1H,
OCH2R), 3.10 3m, 2H, NCH2R), 2.06, 2.02, and 1.86 3s,
9H, COCH3), 1.68 3m, 2H, ±CH2±). 13C NMR 3CDCl3,
100 MHz); d ppm: 170.7, 170.1, 169.4, and 156.2 3CO),
136.5 and 131.2 3PhC), 134.3, 128.4, 127.9, and 123.5
3PhCH), 98.0 3C-1), 71.8, 70.6, 68.8, and 54.4 3C-2 to
C-5), 67.2, 66.3, and 61.8 [all 32), C-6, OCH2R and
CH2Ph], 37.6 and 37.5 [32), NHCH2R], 29.2 [32),
±CH2±], 20.6, 20.5, and 20.3 33COCH3). HR-FABMS
calcd for C31H35O12N2 m/z 627.2189; found 627.2183.
0
0
2.1.18. 3-Methoxy-2-pyridyl 3,4,6-tri-O-acetyl-2-deoxy-
2-phthalimido-b-d-glucopyranoside /17). A solution of
tetra-O-acetyl-2-deoxy-2-phthalimido-b-d-glucopyranose
16 32.77 g, 5.81 mmol) and Ac2O 31.38 mL) in HBr 330% in
AcOH, 90 mL) was stirred for 2 h at room temperature. The
reaction mixture was diluted with toluene 3250 mL), washed
with ice water 32£150 mL), cold saturated NaHCO3
3100 mL), ice water 3100 mL) and concentrated. The resi-
due was redissolved in toluene, concentrated and codistilled
twice with dry toluene 32£75 mL). The residue was re-
dissolved in dry toluene 3110 mL) and silver 3-methoxy-2-
pyridoxide 31.66 g, 1.3 equiv.) was added in one portion.
The system was re¯uxed under vigorous stirring for 1 h,
and allowed to cool down to room temperature. The mixture
was ®ltered through Celitew, and the bed was washed with
toluene 3150 mL). The ®ltrate was treated with saturated
NaHCO3 3100 mL), the biphasic mixture was ®ltered
through a Celitew pad, the pad rinsed with toluene and
both phases separated. The organic phase was washed
with water 3100 mL), dried 3Na2SO4), concentrated and
puri®ed by ¯ash chromatography 3EtOAc/hexanes 1:1)
2.1.20. 3-Benzyloxycarbonylamino-1-propyl 6-O-tert-
butyldiphenylsilyl-2-deoxy-2-phthalimido-b-d-gluco-
pyranoside /19). To
a solution of 18 3303.6 mg,
0.485 mmol) in MeOH 39.7 mL) was added sodium
methoxide 30.5N in MeOH, 0.1 mL) and the reaction
mixture stirred for 6 h at room temperature. The solution
was neutralized with Amberlitew IRC-50S 3H1) ion-exchange
resin, the resin ®ltered off, and washed with MeOH. The
resulting solution was concentrated under vacuum giving 3-
benzyloxycarbonylamino-1-propyl 2-deoxy-2-phthalimido-
b-d-glucopyranoside 30.22 g, 0.41 mmol, 91%) as white
foam: FABMS 3rel. intensity) 501.1 37), [M1H]1. HR-
FABMS calcd for C25H29O10N2 m/z 501.18732; found
501.1859. To
a solution of the preceding product
3219.4 mg, 0.438 mmol) and imidazole 359.6 mg, 2 equiv.)
in dry DMF 32.2 mL) was added TBDPSCl 3180 mL,

S. Hanessian et al. / Tetrahedron 57 52001) 3267±3280
3277
1.5 equiv.) dropwise and the reaction mixture stirred for 5 h
at room temperature. The solution was diluted with
EtOAc 350 mL), extracted with H2O 32£25 mL), dried
3Na2SO4) and concentrated. The residue was puri®ed by
¯ash chromatography 3CH2Cl2/MeOH 20:1) affording 19
under vacuum just before use) was added quickly and the
mixture was stirred under argon for 6 h at room temperature.
The reaction mixture was quenched with a drop of pyridine,
diluted with CH2Cl2 350 mL) and ®ltered through a Celitew
pad. The solution was washed with water 325 mL), 1N HCl
325 mL), water 325 mL), dried 3Na2SO4) and concentrated.
The crude product was puri®ed by ¯ash chromatography
3gradient elution EtOAc/hexanes 1:3 to 1:2) affording 21
3240 mg, 0.165 mmol, 64%, white foam), 22 339.1 mg,
0.027 mmol, 10%, syrup), and a by-product presumed to
be the N-pyridone analog of 20 338.7 mg, 0.046 mmol,
syrup, 18%).
3300 mg, 0.406 mmol, 92%) as
a
white foam:
1
[a]Dˆ120.2 3c 1.0, CHCl3). H NMR 3CDCl3, 400 MHz,
assigned by COSY45); d ppm: 7.80±7.55 3m, 8H), 7.50±
7.393m, 6H), and 7.30 3m, 5H) 3PhCH), 5.20 3d, 1H, H-1,
J1,2ˆ8.4 Hz), 5.00±4.92 3m, 3H, 2CH2Ph and NHCbz), 4.33
3dd, 1H, H-3, J3,2ˆ10.8 Hz, J3,4ˆ8.6 Hz), 4.11 3dd, 1H,
H-2B), 3.97 3m, 2H, H-6 and H-6A), 3.81 3m, 1H,
OCH2R), 3.66 3dd, 1H, H-4, J4,5ˆ9.3 Hz), 3.58 3ddd, 1H,
H-5, J5,6ˆJ5,6Aˆ4.8 Hz), 3.47 3m, 1H, OCH2R), 3.06 3m,
2H, NCH2R), 1.62 3m, 2H, ±CH2±), 1.05 3s, 9H,
SiC3CH3)3). 13C NMR 3CDCl3, 100 MHz); d ppm: 168.3
and 156.2 3CO), 136.5, 132.8, 132.7, and 131.4 3PhC),
135.5, 135.4, 134.0, 129.8, 128.3, 127.8, 127.7, and 123.3
3PhCH), 98.0 3C-1), 74.8, 73.5, 71.6, and 56.2 3C-2 to C-5),
66.9, 66.2, and 64.5 [all 32), C-6, OCH2R and CH2Ph], 38.0
[32), NHCH2R], 29.2 [32), ±CH2±], 26.6 and 19.2 3q)
3SiC3CH3)3). HR-FABMS calcd for C41H47O9N2Si m/z
739.3051; found 739.3085.
1
For 21: [a]Dˆ130.3 3c 1.4, CHCl3). H NMR 3CDCl3,
400 MHz, assigned by COSY45); d ppm: 7.98 3m, 2H),
7.82±7.56 3m, 15H), and 7.50±7.05 3m, 26H) [3m, 44H,
PhCH and ArCH], 5.98 3dd, 1H, H-40, J4 ,3 ˆ3.3 Hz,
0
0
J4 ,5 ˆ0.0 Hz), 5.74 3dd, 1H, 0 H-20, J2 ,1 ˆ8.0 Hz,
0
0
0
0
0
0
J2 ,3 ˆ10.5 Hz), 5.58 3dd, 1H, H-3 ), 5.14 3d, 1H, H-1,
J1,2ˆ8.5 Hz), 5.05 3d, 1H, H-10), 5.00 3m, 2H, CH2Ph),
4.80 3t, 1H, Jˆ6.3 Hz, NHCbz), 4.52 3dd, 1H, H-3
J3,2ˆ10.6 Hz, J3,4ˆ8.6 Hz), 4.18 3dd, 1H, H-2), 4.09±4.03
3m, 2H, H-4 and H-50), 3.88±3.70 3m, 6H, H-6, H-6A, H-60,
H-6A0, OH, and 1OCH2R), 3.46±3.04 3m, 2H, H-5 and 1
OCH2R), 3.20 3m, 2NHCH2R), 1.64 32m, 2H, ±CH2±), 1.10
and 0.92 32 s, 18H, 2C3CH3)3). 13C NMR 3CDCl3,
100 MHz); d ppm: 168.5, 165.5, 165.2, 165.0, and 156.2
3CO), 136.7, 133.7, 132.8, 132.4, 132.1, 131.7, 129.8, and
128.8 3PhC), 135.9, 135.5, 135.4, 134.0, 133.4, 133.2,
130.0, 129.8, 129.6, 128.6, 128.4, 128.2, 127.9, 127.8,
127.7, 123.6, and 123.1 3PhCH), 101.0 and 97.9 3C-1 and
C-10), 66.8, 66.3, 61.8, and 61.0 [all 32), C-6, C-60, OCH2R
and CH2Ph], 79.6, 74.7, 74.2, 71.7, 69.9, 69.5, 67.6, and
56.1 3C-2 to C-5 and C-20 to C-50), 38.3 [32), NHCH2R],
29.4 [32), ±CH2±], 26.9, 26.6, 19.5 3q), and 18.8 3q)
3SiC3CH3)3). FABMS 3rel. intensity) 1473.933.5),
[M1Na]1. Anal. Calcd for C84H86N2O17Si2: C, 69.50; H,
5.97; N, 1.93. Found: C, 70.09; H, 6.66; N, 1.83.
2.1.21. 3-Methoxy-2-pyridyl 2,3,4-tri-O-benzoyl-6-O-
tert-butyldiphenylsilyl-b-d-galactopyranoside /20). To a
solution of 3-methoxy-2-pyridyl 6-O-tert-butyldiphenyl-
silyl-b-d-galactopyranoside24 32.31 g, 4.30 mmol) in
pyridine 343.9mL) was added BzCl 32.1 mL, ,4 equiv.)
dropwise and the solution stirred overnight at room
temperature. The excess BzCl was quenched with MeOH
and the mixture concentrated under vacuum. The crude
product was redissolved in CH2Cl2 350 mL) and washed
with aqueous dilute HCl 31N, 25 mL) and water 325 mL),
dried 3Na2SO4), concentrated, and puri®ed by ¯ash chroma-
tography 3EtOAc/hexanes 1:3) affording 20 32.95 g,
3.52 mmol, 82%) as a white foam: [a]Dˆ1131 3c 1.0,
1
CHCl3). H NMR 3CDCl3, 300 MHz); d ppm: 8.08 32H),
7.86 34H), 7.72 31H), 7.60 33H), 7.50±7.21 314H), 7.04
33H), and 6.90 31H) 38m, 28H, 3PyCH and 25PhCH), 6.53
3d, 1H, H-1, J1,2ˆ8.3 Hz), 6.17 3dd, 1H, H-4, J4,3ˆ3.4 Hz,
J4,5ˆ1.0 Hz), 6.093dd, 1H, H-2, J2,3ˆ10.4 Hz), 5.793dd,
1H, H-3), 4.36 3ddd, 1H, H-5, J5,6ˆJ5,6Aˆ6.5 Hz), 3.86
3m, 2H, H-6 and H-6A), 3.70 3s, 3H, OCH3), 0.98 3s, 9H,
SiC3CH3)3). 13C NMR 3CDCl3, 100 MHz); d ppm: 165.5,
165.4, and 165.0 3CO), 151.8 and 144.1 32PyC), 132.6,
132.4, and 128.93PhC), 136.7, 119.1, and 118.8 33PyCH),
135.5, 135.3, 133.1, 132.9, 132.8, 129.9, 129.7, 129.6,
129.4, 128.3, 128.1, 128.0, 127.5, and 127.3 3PhCH), 94.6
3C-1), 74.2, 72.2, 69.6, and 67.7 3C-2 to C-5), 61.0 [32), C-
6], 55.7 3OCH3), 26.5 and 18.8 3q) 3SiC3CH3)3). HR-
FABMS calcd for C49H48O10NSi m/z 838.3047; found
838.3067.
1
For 22: [a]Dˆ174.2 3c 1.2, CHCl3). H NMR 3CDCl3,
400 MHz, assigned by COSY45); d ppm: 7.98 3m, 2H),
7.70±7.68 3m, 4H), 7.64±7.57 3m, 6H), 7.53±7.51 3m,
2H), 7.48±7.28 3m, 24H), 7.20±7.10 3m, 4H) and 7.05 3t,
2H, Jˆ7.9Hz) [7m, 44H, PhCH and ArCH], 5.82 3dd, 1H,
H-40, J4 ,3 ˆ3.4 Hz, J4 ,5 ˆ0.0 Hz), 5.62 3dd, 1H, H-2 ,
0
0
0
0
0
0
0
0
0
0
J2 ,1 ˆ8.0 Hz, J2 ,3 ˆ10.4 Hz), 5.45 3dd, 1H, H-3 ), 5.00 3s,
2H, CH2Ph), 4.97 3d, 1H, H-1, J1,2ˆ8.6 Hz), 4.78 3m, 2H,
H-10 and NHCbz, J1 ,2 ˆ8.0 Hz), 4.60 3dd, 1H, H-3
J3,2ˆ10.9Hz, J3,4ˆ8.3 Hz), 4.29±4.24 3m, H-2 and OH),
0
0
4.11 3t, 1H, H-50, J5 ,6 ˆJ5 ,6A ˆ6.8 Hz), 4.06 3dd, 1H, H-6,
J6,6Aˆ11.2 Hz, J6,5ˆ2 Hz), 3.90±3.77 3m, 3H, H-6A, H-60
0
0
0
0
0
and 1OCH2R), 3.73±3.693m, 2H, H-4 and H-6A ), 3.53 3m,
H-5), 2.98 3m, 2NHCH2R), 1.64 32m, 2H, ±CH2±), 1.05 and
0.97 32 s, 18H, 2C3CH3)3). 13C NMR 3CDCl3, 100 MHz); d
ppm: 165.2, 165.1, 164.5 and 156.0 3CO), 136.5, 133.4 32C),
132.2, 132.0, 130.6 32C), and 128.4 3PhC), 135.5, 135.4,
135.3, 133.5, 133.3, 133.0, 132.5, 129.7, 129.4, 129.2,
128.4, 128.2, 127.9, 127.7, 127.6, 127.4, 123.2, and 122.6
3PhCH), 101.3 and 97.9 3C-1 and C-10), 66.5, 66.1, 63.4, and
61.2 [all 32), C-6, C-60, OCH2R and CH2Ph], 82.3, 74.1,
71.4, 69.9 32C), 69.7, 67.3, and 54.6 3C-2 to C-5 and C-20 to
C-50), 37.97 [32), NHCH2R], 29.3 [32), ±CH2±], 26.6,
26.4, 19.1 3q), and 18.7 3q) 3SiC3CH3)3). FABMS 3rel.
2.1.22. 3-Benzyloxycarbonylamino-1-propyl O-/2,3,4-tri-
O-benzoyl-6-O-tert-butyldiphenyl-silyl-b-d-galactopyra-
nosyl)-/1!4)-6-O-tert-butyldiphenylsilyl-2-deoxy-2-
phthalimido-b-d-glucopyranoside /21). A 10 mL round
bottom ¯ask containing a mixture of 19 3191.3 mg,
0.259mmol) and 20 3217 mg, 1.0 equiv.), and a magnetic
stirrer was dried overnight under vacuum over P2O5. The
mixture was dissolved in dry CH2Cl2 33.7 mL) and
Cu3TfO)2 3112.4 mg, 1.2 equiv. dried at 2008C for 2 h

3278
S. Hanessian et al. / Tetrahedron 57 52001) 3267±3280
intensity) 1474.5 33.5), [M1Na]1. Anal. Calcd for
C84H86N2O17Si2: C, 69.50; H, 5.97; N, 1.93. Found: C,
70.37; H, 6.78; N, 1.83.
to give the orthoester derivative 25 which was used in the
next step. The residue was redissolved in CH2Cl2 314 mL),
Ac2O 30.79mL, 3 equiv.) was added and the solution stirred
for 1 h at room temperature. The excess Ac2O was quenched
stirring the reaction mixture for 15 min after addition of
MeOH 30.5 mL). The solution was concentrated under
vacuum and the residue redissolved in AcOH 390%,
20 mL). The solution was stirred for 15 min at room
temperature, then diluted with CH2Cl2 3150 mL), washed
with ice water 3100 mL), cold saturated NaHCO3 solution
3100 mL), cold water 3100 mL), dried 3Na2SO4), ®ltered and
concentrated. The crude product was puri®ed by ¯ash chro-
matography 3EtOAc/hexanes 1:4) giving 26 32.80 g,
2.38 mmol, 86%) as a white foam: [a]Dˆ27.8 3c 1.0,
2.1.23. 3-Benzyloxycarbonylamino-1-propyl O-/6-O-tert-
butyldiphenylsilyl-b-d-galactopyranosyl)-/1!4)-2-
acetamido-6-O-tert-butyldiphenylsilyl-2-deoxy-b-d-
glucopyranoside /23). From 24: To a solution of 24 32.0 g,
0.438 mmol) and imidazole 31.07 g, 3 equiv.) in dry DMF
334.8 mL) was added TBDPSCl 32.9mL, 3.0 equiv.) drop-
wise and the reaction mixture stirred for 6 h at room
temperature. The excess TBDPSCl was quenched adding
MeOH 35 mL) and the solution stirred for 30 min. The reac-
tion mixture was concentrated under vacuum and the resi-
due puri®ed by ¯ash chromatography 3CH2Cl2/MeOH 20:1)
affording 23 33.36 g, 2.95 mmol, 85%) as a white foam.
1
CHCl3). H NMR 3CDCl3, 300 MHz); d ppm: 7.76±7.24
3m, 25 PhCH), 6.64 3d, 1H, NHAc, Jˆ8.6 Hz), 5.44 3dd,
1H, H-40, J3 ,4 ˆ3.3 Hz, J4 ,5 ˆ0.0 Hz), 5.15±5.02 3m, 2H),
4.92 3dd, 1H, Jˆ9.5, 9.5 Hz), 4.86 3dd, 1H, Jˆ9.6, 8.4 Hz),
4.18±4.01 3m, 3H), 3.98±3.87 3m, 2H), 3.80±3.74 3m, 2H),
3.64±3.493m, 3H), and 3.36±3.40 3m, 3H) all other protons;
2.05 3s, 3H), 1.92 3s, 3H), 1.88 3s, 3H), and 1.80 3s, 3H)
34COCH3), 1.62 31H) and 1.00 3s, 19H) 32 m, 2 ±CH2±, and
2SiC3CH3)3). 13C NMR 3CDCl3, 100 MHz); d ppm: 171.1,
170.9, 170.7, 170.5, and 156.7 35CO), 136.7, 133.5, 132.6
32C), and 132.2 35CPh), 135.9, 135.5, 135.4, 129.9, 128.5,
128.1, 128.0, 127.8, 127.7, and 127.6 3PhCH), 101.3 and
100.1 3C-1 and C-10), 75.1, 74.1, 73.3, 73.0, 72.9, 71.7,
69.3, and 53.2 3C-2 to C-5 and C-20 to C-50), 66.7, 66.0,
61.3, and 60.8 [all 32), C-6, C-60, OCH2R and CH2Ph], 37.4
[32), NHCH2R], 29.6 [32), ±CH2±], 23.0, 20.8, and 20.7
32C) 34 COCH3), 26.7, 19.2 3q) and 19.0 3q) 3SiC3CH3)3).
FABMS 3rel. intensity) 1177.81 365, [M1H]1). Anal. Calcd
for C63H80N2O16Si2: C, 64.26; H, 6.85; N, 2.38. Found: C,
64.11; H, 7.05; N, 2.34.
0
0
0
0
From 21: To a solution of 21 3112.3 mg, 77.35 mmol) in
MeOH 33.8 mL) was added sodium methoxide
3,10 equiv.) and the reaction mixture was stirred overnight
at room temperature. The solution was neutralized with
Amberlitew IRC-50S 3H1) ion-exchange resin, the resin
®ltered off, and washed with MeOH, the ®ltrate concen-
trated, puri®ed by ¯ash chromatography 3CH3OH/CH2Cl2
1:20) and the product redissolved in EtOH 37.7 mL). To
the re¯uxing mixture was added H2NNH2 hydrate portion-
wise 35 mL at a time, every 15±20 min) until the reaction
was completed. The solution was concentrated, the residue
pumped overnight, and redissolved in MeOH 37.7 mL). To
the solution was added Ac2O 3146 mL, 20 equiv.) and the
solution stirred at room temperature for 1 h. The mixture
was concentrated and puri®ed by ¯ash chromatography
3CH2Cl2/MeOH 20:1) affording 23 349.8 mg, 47.4 mmol,
1
61%) as a white foam: [a]Dˆ26.47 3c 1.0, CH3OH). H
NMR 3CD3OD, 400 MHz, assigned by COSY45); d ppm:
7.80±7.77 3m, 4H), 7.70±7.66 3m, 4H), 7.44±7.25 3m, 17H)
3PhCH), 5.05 3s, 2H, CH2Ph), 4.57 3d, 1H, Jˆ7.7 Hz) and
3d, 1H, Jˆ8.3 Hz) 3H-1 and H-10), 4.22 3dd, 1H, Jˆ11.0,
3.3 Hz), 3.98 3d, 1H, Jˆ11.0 Hz), 3.89±3.83 3m, 5H), 3.77
3dd, 1H, Jˆ10.2, 8.6 Hz), 3.67±3.58 3m, 3H), 3.49±3.43 3m,
3H), 3.27±3.13 3m, 2H, NHCH2R), 1.95 3s, 18H,
SiC3CH3)3). 13C NMR 3CD3OD, 100 MHz); d ppm: 173.5
and 158.8 32CO), 138.4, 134.9, 134.3 32C) and 134.2
35CPh), 137.0, 136.8, 136.7, 130.9, 130.8, 129.4, 128.8
and 128.6 3CHPh), 104.8 and 102.5 3C-1 and C-10), 79.6,
76.8, 76.5, 75.0, 73.9, 72.4, 69.7 and 56.8 3C-2 to C-5 and
C-20 to C-50), 67.6, 67.3, 63.6 and 63.4 [all 32), C-6, C-60,
OCH2R and CH2Ph], 38.91 [32), NHCH2R], 30.8 [32),
±CH2±], 23.0 3COCH3), 27.4, 20.2 3q) and 19.9 3q)
3SiC3CH3)3). FABMS 3rel. intensity) 1073.5 316),
[M1Na]1. Anal. Calcd for C57H74N2O13Si2: C, 65.12; H,
7.09; N, 2.66. Found: C, 64.17; H, 6.88; N, 2.52.
2.1.25. 3-Benzyloxycarbonylamino-1-propyl O-/2,3,4,6-
tetra-O-benzyl-a-d-galactopyranosyl)-O-/1!3)-/2,4-di-
O-acetyl-6-O-tert-butyldiphenylsilyl-b-d-galactopyrano-
syl)-O-/1!4)-3-O-acetyl-2-acetamido-6-O-tert-butyldi-
phenylsilyl-2-deoxy-b-d-glucopyranoside /27). 3a) Using
Cu3TfO)2 as activator. A 25 mL round bottom ¯ask contain-
ing a mixture of 26 31.0 g, 0.849mmol) and 13 30.66 g,
1.2 equiv.), and a magnetic stirrer was dried overnight
under vacuum over P2O5. The mixture was dissolved in
dry toluene 317.0 mL) and Cu3TfO)2 30.614 g, 2.0 equiv.
dried at 2008C for 2 h under vacuum just before use) was
added quickly and the mixture was stirred for 20 h at room
temperature under argon. The reaction mixture was
quenched with a few drops of pyridine, diluted with
CH2Cl2 3100 mL) and ®ltered through a Celitew pad.
The solution was washed with water 350 mL), 1N HCl
350 mL), water 350 mL), dried 3Na2SO4) and concentrated.
The crude was puri®ed by ¯ash chromatography 3EtOAc/
hexanes 1:1) giving 27 367 mg, 0.039mmol, 60%) as a
white foam.
2.1.24. 3-Benzyloxycarbonylamino-1-propyl O-/2,4-di-
O-acetyl-6-O-tert-butyldiphenylsilyl-b-d-galactopyrano-
syl)-/1!4)-3-O-acetyl-2-acetamido-6-O-tert-butyldiphe-
nylsilyl-2-deoxy-b-d-glucopyranoside /26). A solution of
23 32.90 g, 2.77 mmol), triethyl orthoacetate 30.66 mL,
1.3 equiv.) and pyridinium tri¯ate 32 mg) in CH2Cl2
327.7 mL) was stirred at room temperature for 1 h. The
mixture was quenched with DMAP 31.1 g, 3 equiv.), the
solvent removed under vacuum, and the solid residue
dried under high vacuum 320 min at 408C bath temperature)
3b) Using Yb3TfO)3 as activator. A 10 mL round bottom
¯ask containing a mixture of 26 390.6 mg, 0.077 mmol)
and 13 350 mg, 1.0 equiv.), and a magnetic stirrer was
dried overnight under vacuum over Drieritew. The mixture
was dissolved in dry CH2Cl2 31.1 mL) and Yb3TfO)3
347.7 mg, 1.0 equiv. dried at 2008C for 2 h under vacuum
just before use) was added quickly and the mixture stirred

S. Hanessian et al. / Tetrahedron 57 52001) 3267±3280
3279
for 4 h at room temperature under argon, a second portion of
13 350 mg, 1.0 equiv.) was added and the system stirred for
4 h at room temperature. The reaction mixture was diluted
with CH2Cl2 350 mL), washed with water 320 mL), 1N HCl
320 mL), water 320 mL), dried 3Na2SO4) and concentrated.
After puri®cation 3¯ash chromatography, gradient elution
CH2Cl2/MeOH 30:1 to 20:1) the reaction afforded 27
381.9mg, 0.048 mmol, 63%) as a white foam and 28
318.9mg, 0.029mmol, syrup).
b-d-glucopyranoside hydrochloride /2). To a solution of
27 3303.2 mg, 0.229mmol) in dry MeOH 311 mL) was
added sodium methoxide 3,10 equiv.) and the reaction
mixture stirred for 48 h at room temperature. The solution
was concentrated under vacuum. To a solution of the crude
product in THF 32.3 mL) was added in one portion TBAF
30.55 mL, 1.2 equiv.). The solution was stirred for 6 h at
room temperature, concentrated and puri®ed by ¯ash
chromatography 3CH2Cl2/MeOH 15:1) affording 3-benzyl-
oxycarbonylamino-1-propyl
galactopyranosyl-31!3)-O-b-d-galactopyranosyl-31!4)-
O-2-acetamido-2-deoxy-b-d-glucopyranoside 3172 mg,
2,3,4,6-tetra-O-benzyl-a-d-
1
For 27: [a]Dˆ118.2 3c 1.1, CHCl3). H NMR 3CDCl3,
300 MHz); d ppm: 7.78±7.18 3m 45H, PhCH), 6.43 3d,
0
0
1H, NHAc, Jˆ7.9Hz), 5.73 3dd, 1H, H-4 , J4 ,3ˆ3.1 Hz,
0.156 mmol, 68%) as a glass: FABMS 3rel. intensity)
1097.6 313), [M]1, also 1119.5 369), [M1Na]1. A portion
of this product 364 mg, 0.58 mmol) was dissolved in
dioxane 33.6 mL); water was added 318 mL) followed by
20% palladium-on-carbon 3Pearlman's catalyst, ,20 mg).
The mixture was stirred for 2 h under hydrogen 360 psi) at
room temperature, the hydrogen pressure was relieved, HCl
31N in dioxane, ,1 equiv.) was added and the mixture stir-
red under hydrogen 360 psi) overnight. The suspension was
®ltered through a Celitew pad, and the pad rinsed with water
320 mL). The ®ltrate was concentrated under vacuum to
about 5 mL passed through an ion exchange resin column
3Dowexw 1£8±50 in the chloride form); the solution
afforded after rinsing the column with water and lyophiliz-
ing the eluate pure 2 as the hydrochloride 335.8 mg,
0.056 mmol, 96% for the hydrogenation, 65% overall
yield from 27) as a white powder: [a]Dˆ150 3c 1.0,
J4 ,5ˆ0.0 Hz), 5.20 3d, 1H, H-100, J1 ,2 ˆ3.1 Hz), 5.17 3d,
1H) and 5.06 3d, 1H) 3AB, Jˆ12.0 Hz), 4.97 3d, 1H) and
4.54 3d, 1H) 3AB, Jˆ11.3 Hz), 4.88 3d, 1H) and 4.75 3d, 1H)
3AB, Jˆ11.8 Hz), 4.78 32, 2H) and 4.72 3d, 1H) 3AB,
Jˆ11.9Hz), 4.51 3d, 1H) and 4.39 3d, 1H) 3AB,
Jˆ11.8 Hz) 35CH2Ph), 5.1 3m, 2H, NHCbz and H-20),
4.93 3dd, 1H, H-3, J3,2ˆJ3,4ˆ8.7 Hz), 4.63 3d, 1H, H-10,
0
00 00
0
0
J1 ,2 ˆ8.0 Hz), 4.15±3.98 3m, 4H), 3.98±3.82 3m, 6H),
3.80 3dd, 1H, Jˆ3.3, 6.3 Hz), 3.73 3dd, 1H, Jˆ3.6 Hz),
3.65 3dd, 1H, Jˆ8.6, 8.3 Hz), and 3.58±3.45 3m, 18H)
3H-1, H-2, H-4 to H-6A, H-30, H-50 to H-6A0 and H-200 to
H-6A00, and OCH2R), 3.32±3.11 3m, 3H, OCH2R and
2NHCH2R), 1.94 3s, 3H), 1.82 3s, 6H), and 1.78 3s, 3H)
34COCH3), 1.62 3m, 2H, ±CH2±), 1.00 3s 18H) 32 s,
SiC3CH3)3). 13C NMR 3CDCl3, 100 MHz); d ppm: 171.0,
170.8, 169.6, 169.1, and 156.9 35CO), 139.0, 138.1, 136.9,
133.7, 133.1, 132.9, 132.7, and 128.5 3PhC), 136.0, 135.9,
135.7, 135.6, 130.0, 128.8, 128.3, 128.1, 128.0, 127.9,
127.8, 127.6, and 127.5 3PhCH), 101.7 and 100.4 3C-1
and C-10), 95.9 3C-100), 75.0, 73.7, 73.2 32C), 68.4, 66.9,
66.3, and 61.2 32C) [all 32), C-6, C-60, C-600, OCH2R and
5CH2Ph], 78.7, 76.2, 75.6, 75.5, 74.4, 73.5, 73.2 32C), 71.6,
70.0, 65.3, and 53.2 3C-2 to C-5, C-20 to C-50, and C-200 to
C-500), 37.6 [32), NHCH2R], 29.8 3±CH2±), 23.3, 20.9, and
20.7 32C) 34COCH3), 27.1, 26.9, 19.5 3q) and 19.30 3q)
32SiC3CH3)3). FABMS 3rel. intensity) 1700.8 362),
[M1H]1, 1722.8 350), [M1Na]1. Anal. Calcd for
C97H114N2O21Si2: C, 68.53; H, 6.76; N, 1.65. Found: C,
68.04; H, 6.91; N, 1.67.
1
DMSO). H NMR 3D2O, CH3OD internal standard at dˆ
3.35 ppm, 300 MHz);
00 00
d
ppm: 5.15 3d, 1H, H-100,
0
J1 ,2 ˆ3.7 Hz), 4.51 32 d, 2H, H-1 and H-1 , J1,2ˆ7.6 Hz,
0
0
J1 ,2 ˆ7.6 Hz), 4.19±4.15 3m, 2H) and 4.00±3.50 3m, 18H)
[H-2 to H-6 and H-6A, H-20 to H-60 and H-6A0, H-200 to
H-600 and H-6A00 and 2 OCH2R], 3.00 3t, 2H, NCH2R,
J±NCH2±,±CH2±ˆ7 Hz), 2.05 3s, 3H, COCH3), 1.95 3m, 2H,
±CH2±). 13C NMR 3D2O, CH3OD internal standard at
dˆ49.6 ppm, 100 MHz); d ppm: 175.6 3CO), 104.0 and
102.4 3C-1 and C-10), 96.7 3C-100), 80, 78.5, 76.2, 75.9,
73.4, 72, 70.7, 70.5, 70.3, 69.4 and 66.0 3C-3 to C-5, C-20
to C-50, and C-200 to C-500), 69.1, 62.1 32C), 61.2 [all 32),
C-6, C-60, C-600, OCH2R], 56.1 3C-2), 38.9[3 2), NHCH2R],
27.8 [32),±CH2±], 23.2 3COCH3). HR-FABMS calcd for
C23H43O16N2 m/z 603.2612; found 603.2603.
1
For 28: [a]Dˆ137.6 3c 1.0, CHCl3). H NMR 3CDCl3,
300 MHz); d ppm: 7.44±7.08 3m, 20PhCH), 6.98 3dd, 1H,
Jˆ1.5, 7.1 Hz), 6.50 3dd, 1H, Jˆ1.5, 7.4 Hz), 6.01 3dd, 1H,
Jˆ7.1, 7.4 Hz) 33PyCH), 6.27 3d, 1H, H-1, J1,2ˆ9.0 Hz), 5.0
3d, 1H, Jˆ11.4 Hz), 4.75 3s, 2H), 4.64 3d, 2H, Jˆ11.4 Hz),
4.63 3d, 1H, Jˆ11.3 Hz), 4.46 3AB, 2H, Jˆ11.8 Hz), and
4.35 3d, 1H, Jˆ11.3 Hz) 34CH2Ph), 4.06 3m, 2H), and 3.84
3m, 2H) 3H-2, H-3, H-4 and H-5), 3.81 3s, 3H, OCH3), 3.63
3dd, 1H, H-6, J6,5ˆ7.8 Hz, J6,6Aˆ9.1 Hz), 3.56 3dd, 1H,
H-6A, J6A,5ˆ5.6 Hz). 13C NMR 3CDCl3, 100 MHz); d
ppm: 157.9 and 149.6 3PyC), 138.9, 138.2, 137.8, and
137.7 34PhC), 128.4, 128.3, 128.2, 127.9, 127.8, 127.7,
127.6, and 127.4 3PhCH), 123.9and 111.8 32PyCH),
104.93C-1), 83.2, 81.3, 78.0, 75.7, and 73.8 3C-2, C-3,
C-4, C-5, and CHPy), 74.7, 74.5, 73.5, and 74.8 [32),
4CH2Ph], 68.0 [32), C-6], 53.3 3OCH3). HR-FABMS
calcd for C40H42O7N m/z 648.2961; found 648.2976.
Acknowledgements
We thank NSERC of Canada for general ®nancial
assistance.
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