Synthesis of ethyl 2-acetamido-6-S-(5-amino-5-deoxy-β-D- arabinopyranosyl)-2-deoxy-1,6-dithio-β-D-glucopyranoside: A sulfur-linked 5- amino-5-deoxyglycopyranosyl disaccharide

Article abstract of DOI:10.1016/S0008-6215(99)00253-0

A novel pseudo-disaccharide having an imino sugar residue at the non- reducing end, namely, a sulfur-linked 5-amino-5-deoxyglycopyranosyl disaccharide, which is a potential specific inhibitor for glycosidases that recognize not only the glycosidic linkage but also the aglycone moiety, was synthesized. Glycosidation of N-Boc-5-amino-5-deoxy-D-arabinose with ethyl 2- acetamido-3,4-di-O-acetyl-2-deoxy-1,6-dithio-β-D-glucopyranoside in the presence of TsOH gave exclusively the corresponding 1,2-cis-linked thioglycoside. The interglycosidic linkage proved stable enough under conditions for the deprotection of the N-Boc group with TFA. This pseudodisaccharide was unstable at pH > 5, but stable at lower pH. The sulfur-linked 5-amino-5-deoxyglycopyranosyl disaccharide was shown to be formed from 5-amino-5-deoxy-D-arabinose and ethyl 2-acetamido-2-deoxy-1,6- dithio-β-D-glucopyranoside in an acidic buffer solution. (C) 2000 Elsevier Science Ltd.

Full text of DOI:10.1016/S0008-6215(99)00253-0

www.elsevier.nl/locate/carres
Carbohydrate Research 323 (2000) 14–27
Synthesis of ethyl 2-acetamido-6-S-(5-
amino-5-deoxy-b-
D
-arabinopyranosyl)-2-deoxy-1,6-
dithio-b- -glucopyranoside: a sulfur-linked
D
5-amino-5-deoxyglycopyranosyl disaccharide
Katsuhiko Suzuki 1, Hironobu Hashimoto *
Department of Life Science, Faculty of Bioscience and Biotechnology, Tokyo Institute of Technology, Nagatsuta,
Midoriku, Yokohama 226-8501, Japan
Received 21 October 1998; accepted in revised form 28 August 1999
Abstract
A novel pseudo-disaccharide having an imino sugar residue at the non-reducing end, namely, a sulfur-linked
5-amino-5-deoxyglycopyranosyl disaccharide, which is a potential specific inhibitor for glycosidases that recognize
not only the glycosidic linkage but also the aglycone moiety, was synthesized. Glycosidation of N-Boc-5-amino-5-de-
oxy-D
-arabinose with ethyl 2-acetamido-3,4-di-O-acetyl-2-deoxy-1,6-dithio-b-D-glucopyranoside in the presence of
TsOH gave exclusively the corresponding 1,2-cis-linked thioglycoside. The interglycosidic linkage proved stable
enough under conditions for the deprotection of the N-Boc group with TFA. This pseudodisaccharide was unstable
at pH\5, but stable at lower pH. The sulfur-linked 5-amino-5-deoxyglycopyranosyl disaccharide was shown to be
formed from 5-amino-5-deoxy-
acidic buffer solution. © 2000 Elsevier Science Ltd. All rights reserved.
D
-arabinose and ethyl 2-acetamido-2-deoxy-1,6-dithio-b-D-glucopyranoside in an
Keywords: Imino sugar; 5-Amino-5-deoxyglycopyranosyl thioglycoside; Glycosidation; N,S-acetal
carbon. Glycosidases are usually classified as
aglycone-specific or non-specific, based on
their substrate specificity. Many imino sugars
(pseudo-sugars with nitrogen in the ring), or
polyhydroxy-piperidines and -pyrrolidines,
have remarkable inhibitory activities against
exo-glycosidases [1], due to their strong affini-
ties for the carboxylate group in the active site
of glycosidases. In general, glycosidases have
rather strict recognition requirements for the
glycone moiety of their substrate. Imino sug-
ars therefore show specific inhibition against
glycosidases that hydrolyze glycosides having
the same configuration as the imino sugar [2].
In contrast, most exo-glycosidases are not spe-
cific for the aglycone moiety of the substrate
glycoside.
1. Introduction
Glycosidases, among the most important
carbohydrate enzymes, are responsible for the
control of various biological phenomena. In-
hibitors of these enzymes aid in investigations
of several important biochemical processes.
Such inhibitors are commonly based on natu-
rally occurring or synthetic substrate ana-
logues, wherein the ring oxygen is substituted
by other atoms such as nitrogen, sulfur, and
* Corresponding author. Tel.: +81-45-924-5704; fax: +
81-45-924-5805.
E-mail address: hhashimo@bio.titech.ac.jp (H. Hashimoto)
1 Present address: College of Science and Engineering,
Iwaki Meisei University, Iwaki, Fukushima 970, Japan.
0008-6215/00/$ - see front matter © 2000 Elsevier Science Ltd. All rights reserved.
PII: S0008-6215(99)00253-0

K. Suzuki, H. Hashimoto / Carbohydrate Research 323 (2000) 14–27
15
Pseudo-oligosaccharides having a pseudo
sugar at the non-reducing end are potential
candidates for specific inhibitors of glycosi-
dases that recognize not only the glycosidic
linkage but also the aglycone moiety. Re-
oxyglycopyranose and a 6-thio sugar in an
acidic buffer solution.
2. Results and discussion
cently, we synthesized 5-thio- -fucose-contain-
L
ing disaccharides having a-(1“6), a-(1“3),
or a-(1“4) linkages to GlcNAc, and an a-
(1“2) linkage to Gal [3]. Only the a(1“2)-
linked disaccharide showed inhibitory activity
Our target pseudodisaccharide, namely a
5-amino-5-deoxyglycopyranosyl disaccharide,
was synthesized through glycosidation of pro-
tected imino sugars with a sugar thiol, fol-
lowed by deprotection. In this coupling
reaction, 5-alkoxycarbonylamino-5-deoxygly-
copyranoses were selected as donors, based on
their stability under acidic glycosidation con-
ditions [7].
In general, the synthesis of 5-amino-5-de-
oxypentopyranose can be achieved in shorter
steps than for 5-amino-5-deoxyhexopyranoses,
because the conversion of the primary hy-
droxyl into an amino group is easy and pre-
vents stereochemical problems. To examine
the glycosidation reaction of imino sugars,
N-protected 5-amino-2,3,4-tri-O-benzyl-5-de-
against Bacillus sp. K40T a- -fucosidase (EC
L
3.2.1.63), which hydrolyzes the a- -Fuc-(1“
L
2) linkage specifically.
Some pseudo-oligosaccharides having de-
oxynojirimycin or an analogue (a 1,5-dideoxy-
1,5-iminohexitol) [4] and a-homonojirimycin
(a 2,6-dideoxy-2,6-iminoheptitol) [5] at the re-
ducing end have been synthesized. However,
an aminal-type pseudo-oligosaccharide having
an imino sugar residue at the non-reducing
end, even a disaccharide, had not been synthe-
sized prior to our preliminary report [6], be-
cause O-glycosyl derivatives of imino sugars
(N,O-acetal 1) are extremely unstable, being
prone to elimination giving the corresponding
cyclic imines [7]. On the other hand, several
stable C-linked pseudo-disaccharides having
an imino sugar at the non-reducing end have
been reported [8].
oxy-
D
-arabinoses 14, 15, and 16 were synthe-
sized from
D
-arabinose as a model imino
sugar (Scheme 1). An azido group was intro-
duced by substitution on the 5-O-mesylated
furanoside 4 with NaN3 in Me2SO. After O-
deacetylation, the hemiacetal 6 was reduced
with NaBH4 in MeOH to afford 5-azido-5-de-
oxy- -arabinitol (7), whose structure was
D
confirmed by the NMR spectrum of its te-
traacetate 8. The 1-trityl ether 9, obtained in
high yield by conventional tritylation of 7, was
benzylated to give the tri-benzyl ether 10. The
azido group of 10 was converted into an
amino group, which was protected as benzyl
carbamate (N-Z) 11, the 9-fluorenylmethyl
carbamate (N-Fmoc) 12, and the tert-butyl
carbamate (N-Boc) 13. The hemiaminals
(N,O-acetals) 14, 15, and 16 were constructed
by Swern oxidation [9] of the amino alcohols
11, 12, and 13, respectively.
Reaction of the 1-acetates of the aminals
14, 15, and 16 with a simple alcohol or a thiol
in the presence of Me3SiOTf (1 equiv) in
CH2Cl2 gave the corresponding glycosides 17–
21 (Table 1, entries 1–5). While the yields of
the N-Z and N-Fmoc derivatives were good,
that of the N-Boc derivative (entry 5) was
lower due to partial decomposition of the Boc
In a previous communication, we reported
the synthesis of a novel pseudo-disaccharide 2
having an imino sugar residue at the non-re-
ducing end, linked to the aglycone sugar
through a thioaminal linkage [7]. The thioami-
nal linkage was found to be more stable than
the corresponding O-glycosidic (aminal) link-
age. In this paper, we describe details of the
unique character of a 5-amino-5-deoxygly-
copyranosyl (polyhydroxypiperidyl) thiogly-
coside. In aqueous solution, this thioglycoside
of a 5-amino-5-deoxyglycopyranose is un-
stable at pH\5; it anomerizes rapidly or is
hydrolyzed, but is stable at lower pH. The
5-amino-5-deoxyglycopyranosyl thioglycoside
(N,S-acetal) was formed from a 5-amino-5-de-

16
K. Suzuki, H. Hashimoto / Carbohydrate Research 323 (2000) 14–27
Scheme 1. Synthesis of N-protected 5-amino-2,3,4-tri-O-benzyl-5-deoxy-D-arabinoses 14–16. Reagents: (i) MsCl, pyridine; (ii)
NaN3, Me2SO; (iii) NaOMe, MeOH; (iv) NaBH4, MeOH; (v) Ac2O, pyridine; (vi) TrCl, pyridine; (vii) (a) BnBr, NaH, DMF, (b)
70% aqueous AcOH; (viii) LiAlH4, THF then H2O, ZCl or FmocCl or Boc2O; (ix) (COCl)2, Me2SO, Et3N, CH2Cl2.
Table 1
Glycosylation with N-protected 5-amino-5-deoxy-
D
-arabinose
Entry
Donor
14
Acceptor (NuH)
(CH3)3CCH2OH
EtSH
Method a
Yield (%)
quant.
quant.
79
b:a b
1:0
Product
1
2
3
4
5
6
7
8
A
A
A
A
A
B
B
B
17 R=Z,
Nu=OCH2C(CH3)3
18 R=Z,
Nu=SEt
14
3:1
15
EtSH
2.8:1
3.1:1
3.8:1
7.3:1
1:0
19 R=Fmoc,
Nu=SEt
20 R=Fmoc,
Nu=SC6H11
21 R=Boc,
Nu=SEt
22 R=Boc,
Nu=SC6H11
23 R=Boc,
Nu=OC6H11
24 R=Boc,
Nu=OMe
15
C6H11SH
EtSH
73
16
40
16
C6H11SH
C6H11OH
MeOH
72
16
73
16
88
1:0
a
,
(A) (i) Ac2O, pyridine; (ii) NuH, Me3SiOTf (1.1 equiv), 4 A molecular sieves, CH2Cl2; (B) NuH, TsOH (1 equiv), CH2Cl2.
b Ratio was determined by intensities of H NMR signals of H-1.
1

K. Suzuki, H. Hashimoto / Carbohydrate Research 323 (2000) 14–27
17
1
4
Scheme 2. Conformational change of the thioglycoside 22b of 5-amino-5-deoxy-
tion.
D
-arabinose from C4 to C1 (25) by N-deprotec-
4
group under the coupling conditions. We then
found that the free aminal 16 reacted readily
with alcohols in the presence of TsOH (1
equiv) as catalyst, giving the glycosides 22–24
in satisfactory yields (entries 6–8). This glyco-
sylation reaction with an N-protected imino
sugar using TsOH is extremely convenient. In
the reaction with alcohols, the more thermo-
dynamically stable b-O-glycosides were ob-
tained exclusively. The stereoselectivities in
these glycosylations can be explained by an
enhanced anomeric effect in N–C–S systems
compared with the O–C–O system [10].
the sulfur atom. The preference for the C1
conformation in 25 is attributed to the posi-
tive charge on the ring nitrogen atom, which
causes an effect similar to that originally re-
ported in the case of exocyclic quaternary
substituents and termed the reverse anomeric
effect [11]. The change of anomeric ratio indi-
cates the anomerization of 22 or 25 under
these deprotection conditions.
The aforementioned glycosylation was ap-
plied to the synthesis of a pseudo-disaccha-
ride. 5-Azido-5-deoxy-
D
-arabinose (6) was
-ara-
converted into N-Boc-5-amino-5-deoxy-
D
The N-Boc group of the thioglycoside was
successfully removed, whereas deprotection of
the N-Z and N-Fmoc groups was unsuccessful
because of ensuing decomposition of the gly-
coside. Treatment of the N-Boc thioglycoside
22 (b:a=7.3:1) with 2:1 TFA–CH2Cl2 gave
the N-unprotected glycoside 25 as the pure b
anomer in good yield (Scheme 2). The thioam-
inal structure of 25 is supported by the char-
acteristic 13C NMR signal of the anomeric
carbon (l 60.04). It is noteworthy that the
deprotection followed by salt formation
binose (26) in good yield by catalytic hydro-
genation in the presence of Boc2O. Ethyl
2 - acetamido - 3,4 - di - O - acetyl - 2 - deoxy - 1,6-
dithio-b-
D-glucopyranoside (27) was obtained
from ethyl 2-acetamido-2-deoxy-1-thio-b-
D-
glucopyranoside [12]. Condensation of the
aminal 26 with the 6-thio sugar 27 in the
presence of TsOH (1 equiv) gave the corre-
sponding thioglycoside as a single anomer in
80% yield, and this was converted into the
pentaacetate 28 quantitatively. The conforma-
tion of the 5-amino-5-deoxyglycopyranose
1
1
causes a conformational change from C4 of
ring was confirmed to be C4 by the small
4
1
22b to C1 of 25. The C4 conformation of 22b
coupling constants between H-4 and the two
H-5 protons. The J1%,2% value of 4.6 Hz there-
fore indicates an axial–equatorial relationship
between H-2 and H-1, that is, a 1,2-cis glyco-
sidic linkage. The 13C NMR spectrum of the
pentaacetate 28 in CDCl3 shows two signals of
the thioaminal C1% (l 61.60 and 60.95) due to
a 1:1 mixture of E and Z isomers of the N-Boc
group [7]. Exclusive formation of the b-linked
disaccharide in this glycosidation seems to be
caused by the bulkiness of the 6-thio sugar 27.
O-Deacetylation of the thioglycoside 28,
followed by deprotection of the N-Boc group
of 29 with 2:1 TFA–CH2Cl2 gave 30 quantita-
tively (Scheme 3). The conformational change
1
is confirmed by the H NMR data for J2,3 9.9
Hz, J4,5eB0.3 Hz, and J4,5aB0.3 Hz. In con-
trast, a large value for one of two coupling
constants between H-4 and H-5 (J4,5a 11.6 Hz)
for 25 indicates a conformational change of
1
4
the iminopyranose ring from C4 to C1. The
NOE correlation observed between H-1 and
1
H-5 in the H NMR spectrum of 25 also
supports the 4C1 conformation and 1,2-cis-gly-
coside. For the O-glycoside 24, deprotection
of the N-Boc group caused successive elimina-
tions to give 3-benzyloxypyridine and benzyl
alcohol. The stability of the thioglycoside can
be interpreted in terms of the lower basicity of

18
K. Suzuki, H. Hashimoto / Carbohydrate Research 323 (2000) 14–27
of the 5-amino-5-deoxyglycopyranose ring
protected imino sugar 32 gradually changed
into 1,5-imino-1,5-dideoxy- -erythro-pentu-
lose hydrate 33 via 34 or 35 by an Amadori
rearrangement, and the a anomer of 30 also
exists in the mixture (Scheme 4). These
changes can be traced by 1H NMR
spectroscopy.
1
4
from C4 to C1 was similar to that observed
from 22 to 25. Thus, the disaccharide having
an imino sugar residue at the non-reducing
end was synthesized by linking the glycone
and aglycone part through a thioglycosidic
linkage.
D
This pseudo-disaccharide 30 was found to
be stable at low pH, but was hydrolyzed
rapidly at pH\5 to afford ethyl 2-acetamido-
The a anomer of 30 is deduced to be
formed by a reversible addition of thiol to
imine in aqueous solution. Therefore, the
iminopyranosyl disaccharide can be formed by
2-deoxy-1,6-dithio-b- -glucopyranoside (31).
D
Under the mild acidic conditions, the N-un-
mixing 5-amino-5-deoxy- -arabinose 32 and
D
Scheme 3. Synthesis of ethyl 2-acetamido-6-S-(5-amino-5-deoxy-D-arabinopyranosyl)-2-deoxy-1,6-dithio-D-glucopyranoside (30).
Reagents (i) (a) TsOH, CH2Cl2, (b) Ac2O, pyridine; (ii) NaOMe, MeOH; (iii) TFA, CH2Cl2.
Scheme 4. Equilibrium between the pseudo-disaccharide 30 and its component sugars, that is, the imino sugar 32 and the thio
sugar 31.

K. Suzuki, H. Hashimoto / Carbohydrate Research 323 (2000) 14–27
19
31 in an acidic buffer solution. Recently, novel
isomeric N,S-acetalic disaccharides having an
endocyclic sulfur atom and an exocyclic nitro-
gen atom were synthesized by Pinto and co-
workers [13], and were found to exist as
anomeric mixtures in aqueous solution. They
proposed that anomerization proceeds by en-
docyclic CꢀS bond cleavage to give the inter-
mediate iminium ions. Epimerization of some
thiazoline derivatives in an aqueous solution
has also been reported [14].
In this paper, the first synthesis of the 5-
amino-5-deoxyglycopyranosyl thioglycoside-
type pseudo-disaccharide having an imino
sugar residue at the non-reducing end was
described. Glycosidation of an N-Boc aminal
26 with a 6-thio-sugar 27 in the presence of
TsOH gave the corresponding 1,2-cis-linked
thioglycoside exclusively. The interglycosidic
thioaminal linkage was proven to be stable
enough under the deprotection condition of
the N-Boc group with TFA. This pseu-
dodisaccharide was unstable at pH\5, but
Then, we examined the formation of 5-
amino-5-deoxyglycopyranosyl thioglycoside-
type disaccharides in aqueous solution in
order to prove our above described hypothe-
easily formed from 5-amino-5-deoxy-
D
-ara-
-glu-
binose (32) and N-acetyl-6-thio-
D
cosaminide (31) in a mild acidic buffer
solution.
sis. N-Acetyl-6-thio- -glucosaminide (31) was
D
prepared by deacetylation of 27 using aqueous
ammonia in the presence of dithiothreitol. 5-
Amino-5-deoxy-
D
-arabinose (32) was pre-
3. Experimental
pared from 5-azido-5-deoxy-
D
-arabinose 6 via
N-Boc-5-amino-5-deoxypyranose. The 500
MHz NMR spectrum of the major compound
formed in a 1:1 mixture of 32 and 31 in an
acidic buffer (CD3COOD–CD3COONa, pD
about 3.4) after 30 min was found to be in
good agreement with that of the synthesized
disaccharide 30. The formation of 1,5-imino-
General methods.—Melting point are un-
1
corrected. H NMR spectra were recorded at
270 MHz (Jeol JMN-EX-270) and at 500
MHz (Jeol JMN-GX-500). 13C NMR spectra
were recorded at 67.5 MHz (Jeol JMN-EX-
270) with the solvent peak (CDCl3; 77.0 ppm)
or acetone (30.6 ppm in D2O) as the reference.
Mass spectra were obtained on JMS-700MS
(Jeol) or JMS-HX110 (Jeol) spectrometers.
Optical rotations were measured at 589 nm
with a JascoJIP-4 digital polarimeter (at
24 °C). IR spectra were recorded using NaCl
plates on a Hitachi 270-30. Thin-layer chro-
matography (TLC) was performed on
Kieselgel 60 F254 (E. Merck) plates and de-
tected by charring with 5% H2SO4 solution or
1% Ce(SO4)2 –1.5% (NH4)6Mo7O24·4 H2O–
10% H2SO4. Silica gel column chromatogra-
phy was conducted on E. Merck Silica Gel 60
(70–230 mesh).
1,5-dideoxy- -erythro-pentulose hydrate (33)
D
was also confirmed by the signal of the H-4
proton, which was assigned by comparison of
an authentic sample. Under this condition, the
disaccharide exists as a mixture of anomeric
isomers (a:b=1:1).
Thus, the reversible conversions between
the N,S-acetal 30 and its plausible degradative
components (the sugar thiol 31 and the cyclic
imine 34) were confirmed. The formation of
the imine 34 was further supported by its
hydrated product 32 and 1,5-dideoxy-1,5-
imino- -erythro-pentulose (33), which was
D
formed by an Amadori rearrangement via the
enaminol 35, as shown in Scheme 4.
1,2,3-Tri-O-acetyl-5-O-methylsulfonyl- -
D
arabinofuranose (4).—To a pyridine (50 mL)
solution of 3 [15] (22.5 g, 86.8 mmol) was
added MsCl (8.1 mL, 0.10 mol) dropwise over
5 min at 0 °C. After stirring for 15 min at
room temperature (rt), the mixture was
poured into satd aq NaHCO3, diluted with
EtOAc, and washed with brine and water. The
organic layer was dried (MgSO4) and concen-
trated in vacuo. The residue was purified by
silica-gel column chromatography (2:1 hex-
In general, construction of the glycosylic
linkage in the aqueous solution, so-called acid
reversion, is of no practical use. Therefore,
this unique character found here, that the
5-amino-5-deoxyglycopyranosyl thioglycoside-
type pseudodisaccharide is easily formed from
N-unprotected 5-amino-5-deoxyglycopyranose
and thio sugar in a mild acidic condition
seems to be worthy of notice.

20
K. Suzuki, H. Hashimoto / Carbohydrate Research 323 (2000) 14–27
34.29; H, 5.18; N, 23.99. Found: C, 34.68; H,
5.17; N, 23.72.
ane–EtOAc) to afford 24.3 g of 4 (79%) as an
anomeric mixture (a:b=1.9:1); 1H NMR
(CDCl3): l 6.21 (s, 0.7 H, H-1a), 5.23 (d, 0.7
H, J2,3 1.3 Hz, H-2a), 5.05 (dd, 0.7 H, J3,4 4.6
Hz, H-3a), 6.39 (d, 0.3 H, J1,2 4.3 Hz, H-1b),
5.37–5.28 (m, 0.7 H, H-2b, 3b), 4.54–4.20
(m, 3 H, H-4,5a,5b), 3.07 (s, 3 H, OMs), 2.15,
2.13, 2.10 (each s, 12 H, OAc). Anal. Calcd
for C12H18O10S: C, 40.67; H, 5.12; Found: C,
40.92; H, 5.15.
5-Azido-5-deoxy- -arabinitol (7).—To a
D
MeOH (10 mL) solution of 6 (100 mg, 0.57
mmol) was added NaBH4 (43 mg, 1.14
mmol). After being stirred for 30 min at rt,
the mixture was neutralized with a large ex-
cess of AcOH and evaporated. The residue
was purified by silica-gel column chromatog-
raphy (9:1 CHCl3–MeOH) to afford 7 (99.7
mg, 100%) as crystals: mp 86–88 °C; [h]D
1,2,3-Tri-O-acetyl-5-azido-5-deoxy- -ara-
D
1
+2.3° (c 0.6, MeOH); H NMR (D2O): l
binofuranose (5).—To a solution of 4 (5.0 g,
14.1 mmol) in Me2SO (80 mL) was added
NaN3 (2.0 g, 31.0 mmol). After being stirred
at 60 °C for 24 h, the mixture was diluted
with EtOAc and washed with water. The or-
ganic layer was dried over MgSO4, and con-
centrated in vacuo. The residue was purified
by silica-gel column chromatography (2:1
hexane–EtOAc) to afford 2.88 g of 5 (68%)
as an anomeric mixture (a:b=1:1); [h]D
+73.6° (c 0.46, CHCl3); IR (KBr) wmax 2110,
3.99–3.88 (m, 2 H), 3.70–3.47(m, 5 H); 13C
NMR (D2O): l 70.70, 69.99, 69.72, 63.02,
53.71. Anal. Calcd for C5H11N3O4: C, 33.90;
H, 6.26; N, 23.72. Found: C, 33.85; H, 6.16;
N, 23.26.
1,2,3,4-Tetra-O-acetyl-5-azido-5-deoxy- -
D
arabinitol (8).—To a pyridine (5 mL) solution
of 7 (100 mg, 0.56 mmol) was added Ac2O
(0.27 mL, 2.80 mmol). After being stirred for
5 h at rt, the mixture was quenched by a large
excess of MeOH and evaporated. The residue
was purified by silica-gel column chromatog-
raphy (3:1 hexane–EtOAc) to afford 8 (178
mg, 92%) as a syrup: [h]D +41.9° (c 0.6,
CHCl3); IR (KBr disk) wmax 2968, 2110, 1743,
1
1743 cm−1; H NMR (CDCl3): l 6.41–6.40
(m, 0.5 H, H-1b), 6.22 (s, 0.5 H, H-1a), 5.38–
5.36 (m, 1 H, H-2b, 3b), 5.22 (d, 0.5 H, J2,3
1.3 Hz, H-2a), 5.05 (dd, 0.5 H, J3,4 4.6 Hz,
H-3a), 4.30 (ddd, 0.5 H, J4,5a 3.3, J4,5b 4.6 Hz,
H-4a), 4.14 (br s, 0.5 H, H-4b), 3.70 (dd, 0.5
H, J5a,5b 13.5 Hz, H-5aa), 3.52 (dd, 0.5 H,
J4,5a 3.6, J5a,5b 13.2 Hz, H-5ab), 3.47 (dd, 0.5
H, J4,5b 2.3 Hz, H-5bb), 3.46 (dd, 0.5 H,
H-5ba), 2.14, 2.13, 2.12, 2.11, 2.09 (each s, 12
H, OAc). Anal. Calcd for C11H15N3O7: C,
43.86; H, 5.02; N, 13.95. Found: C, 43.78; H,
4.87; N, 13.86.
1
1440 cm−1; H NMR (CDCl3): l 5.42–5.34
(m, 2 H, H-2,3), 5.13 (ddd, H, J3,4 8.6, J4,5a
3.3, J4,5b 5.6 Hz, H-4), 4.25 (dd, H, J1a,1b 11.9,
J1a,2 5.3 Hz, H-1a), 3.95 (dd, 1 H, J1b,2 7.0 Hz,
H-1b), 3.50 (dd, 1 H, J5a,5b 13.5 Hz, H-5a),
3.32 (dd, 1 H, H-5b), 2.15, 2.10, 2.08, 2.05
(each s, 12 H, OAc×4); 13C NMR (CDCl3):
l 170.15, 169.79, 169.49, 169.38, 68.81, 68.59,
67.80, 61.57, 50.42, 20.45, 20.40, 20.34. Anal.
Calcd for C13H19N3O8: C, 45.22; H, 5.55; N,
12.17. Found: C, 45.46; H, 5.72; N, 11.69.
5-Azido-5-deoxy- -arabinofuranose (6).—
D
To a solution of 5 (2.88 g, 9.58 mmol) in
MeOH (15 mL) was added NaOMe (50 mg,
0.93 mmol). After being stirred for 5 h with
sonication, the mixture was neutralized with
Dowex 50W-X8 resin, and evaporated in
vacuo to afford 6 (1.67 g, 100%) as an
anomeric mixture. (a:b=1:1); [h]D +5.9° (c
0.23, MeOH); IR (KBr disk) wmax 3400, 2926,
5-Azido-5-deoxy-1-O-triphenylmethyl- -ara-
D
binitol (9).—To a pyridine (50 mL) solution
of 7 (4.50 g, 25.6 mmol) was added TrCl (8.56
g, 30.7 mmol). After being stirred for 48 h at
rt, the mixture was quenched by a large ex-
cess of MeOH and evaporated. The residue
was purified by silica-gel column chromatog-
raphy (3:1 hexane–EtOAc) to afford 9 (8.9 g,
83%) as crystals: mp 97–102 °C; [h]D +3.9°
1
2110 cm−1; H NMR (D2O): l 5.33 (dd, 0.5
H, J 0.7, J 3.3 Hz, H-1a), 5.28 (d, 0.5 H, J1,2
3.0 Hz, H-1b), 4.24–3.90 (m, 3 H, H-2, 3, 4),
3.68 (dd, 0.5 H, J 3.6, J 13.7 Hz, H-5a), 3.63
(dd, 0.5 H, J 3.3, J 13.7 Hz, H-5a); 3.48 (dd,
0.5 H, J 6.0 Hz, H-5b), 3.46 (dd, 0.5 H, J 6.3
Hz, H-5b). Anal. Calcd for C5H9N3O4: C,
1
(c 0.68, MeOH); H NMR (CDCl3): l 7.30
(m, 15 H, Ph), 3.97 (br s, 1 H), 3.79 (m, 1 H),
3.55–3.39 (m, 4 H), 3.30 (dd, 1 H). Anal.
Calcd for C24H25N3O4: C, 68.70; H, 6.01; N,
10.03. Found: C, 68.64; H, 6.01; N, 9.83.

K. Suzuki, H. Hashimoto / Carbohydrate Research 323 (2000) 14–27
21
1
CHCl3); H NMR (CDCl3): l 7.33–7.25 (m,
20 H, Ph), 5.12 (br s, 1 H, NH), 5.09, 5.04
(each d, 2 H, J 12.2 Hz, benzyl), 4.73–4.49
(m, 6 H, benzyl), 3.84–3.43 (m, 7 H), 2.19 (br
s, 1 H, OH); 13C NMR (CDCl3): l 156.44,
138.04, 137.93, 137.68, 136.53, 128.37, 128.21,
128.10, 127.92, 127.84, 127.75, 127.58, 79.71,
79.14, 77.77, 74.29, 72.78, 71.81, 66.51, 61.21,
40.65. Anal. Calcd for C34H37NO6: C, 73.49;
H, 6.71; N, 2.52. Found: C, 73.98; H, 6.88; N,
2.45.
5-Azido-2,3,4-tri-O-benzyl-5-deoxy- -ara-
D
binitol (10).—To a DMF (100 mL) solution
of 9 (8.5 g, 20.3 mmol) was added 55% NaH
(3.4 g, 0.14 mol) at 0 °C and the mixture was
stirred for 30 min at rt. To the mixture was
added BnBr (8.1 mL, 0.10 mol) dropwise
slowly and stirred for 3 h at rt, then quenched
by a large excess of NaOMe at 0 °C. The
reaction mixture was poured into H2O and
diluted with EtOAc. The organic layer was
washed with brine, followed by extraction
with EtOAc, dried (MgSO4) and concentrated
in vacuo. The residue was purified by silica-
gel column chromatography (6:1 hexane–
EtOAc) to afford the benzylated compound
(13.3 g, 95%). A suspension of this compound
(13.0 g, 18.9 mmol) in 70% aq AcOH (300
mL) was stirred for 4 h at 60 °C, the mixture
was filtrated through a Celite and the filtrate
concentrated in vacuo. The residue was
purified by silica-gel column chromatography
(3:1 hexane–EtOAc) to afford 10 (5.32 g,
63%): mp 48–49 °C; [h]D −6.7° (c 0.99,
CHCl3); IR (KBr disk) wmax 3478, 3059, 3028,
2,3,4-Tri-O-benzyl-5-deoxy-5-(9-fluorenyl-
methyloxycarbonylamino)- -arabinitol (12).—
D
Compound 12 was obtained by reacting 10
with FmocCl in place of ZꢀCl in the same
manner as described for 11, and purified by
silica-gel column chromatography (2:1 hex-
ane–EtOAc) to afford a colorless syrup
(95%): [h]D +12.4° (c 0.84, CHCl3); 1H
NMR (CDCl3): l 7.75–7.24 (m, 23 H, aro-
matic), 5.10 (br s, 1 H, NH), 4.73–4.53 (m, 6
H, benzyl), 4.38–4.35 (br d, 2 H, FmocCH2),
4.17 (dd, 1 H, J 6.76 Hz, FmocCH), 3.83–
3.40 (m, 7 H), 2.02 (br s, 1 H, OH); 13C
NMR (CDCl3): l 156.44, 143.83, 141.19,
138.01, 137.93, 137.70, 128.37, 128.27, 128.21,
128.07, 127.98, 127.84, 127.78, 127.73, 127.55,
126.92, 124.94, 119.86, 79.75, 79.174, 77.85,
74.27, 72.76, 71.90, 66.49, 61.15, 47.14, 40.72.
Anal. Calcd for C41H41NO6: C, 76.49; H,
6.42; N, 2.18. Found: C, 76.22; H, 6.44; N,
1.97.
1
2878, 2104, 1497, 1452, 1401 cm−1; H NMR
(CDCl3): l 7.33–7.17 (m, 15 H, Ph), 4.71,
4.65, 4.63, 4.62, 4.54, 4.48 (each d, 6 H, J
11.9 Hz, benzyl), 3.85–3.46 (m, 7 H, H-
1a,1b,2,3,4,5a,5b), 2.12 (br s, 1 H, OH); 13C
NMR (CDCl3): l 138.01, 137.79, 137.48,
128.41, 128.16, 127.94, 127.89, 127.82, 78.99,
78.91, 78.62, 74.27, 72.60, 72.44, 61.33, 50.98.
Anal. Calcd for C26H29N3O4: C, 69.78; H,
6.53; N, 9.39. Found: C, 69.81; H, 6.43; N,
9.29.
2,3,4-Tri-O-benzyl-5-tert-butyloxycarbonyl-
amino-5-deoxy- -arabinitol (13).—Compound
D
13 was obtained by reacting 10 with Boc2O in
place of ZꢀCl in the same manner as de-
scribed for 11. Compound 13 was purified by
silica-gel column chromatography (2:1 hex-
ane–EtOAc) to afford a colorless syrup
(90%): [h]D +17.6° (c 2.56, CHCl3); 1H
NMR (CDCl3): l 7.34–7.24 (m, 15 H, Ph),
4.90 (br s, 1 H, NH), 4.72, 4.66 (each d, 2 H,
J 11.2 Hz, benzyl), 4.62 (s, 2 H, benzyl), 4.57,
4.50 (each d, 2 H, J 11.7 Hz, benzyl), 3.84–
3.64 (m, 5 H), 3.46–3.42 (m, 2 H), 2.16 (br s,
1 H, OH), 1.42 (s, 9 H, t-Bu); 13C NMR
(CDCl3): l 155.96, 138.10, 137.99, 137.81,
128.28, 128.09, 127.78, 127.73, 127.64, 79.68,
79.17, 79.01, 77.83, 74.27, 72.72, 71.68, 61.22,
39.98, 28.27. Anal. Calcd for C31H39NO6: C,
71.38; H, 7.54; N, 2.69. Found: C, 70.98; H,
7.06; N, 2.22.
2,3,4 - Tri - O - benzyl - 5 - benzyloxycarbonyl-
amino - 5 - deoxy -
D
- arabinitol (11).—To a
THF (20 mL) solution of 10 (495 mg, 1.11
mmol) was added LiAlH4 (84 mg, 2.22
mmol). The mixture was stirred at rt until the
starting material disappeared on TLC, and
poured into ice–water (30 mL). To the solu-
tion was added ZꢀCl (317×10−3 mL, 2.22
mmol) dropwise at 0 °C. The mixture was
separated and the aqueous layer extracted
with CHCl3. The combined extracts were
washed with water, dried (MgSO4) and con-
centrated in vacuo. The residue was purified
by silica-gel column chromatography (2:1
hexane–EtOAc) to afford 11 (585 mg, 95%)
as a colorless syrup: [h]D +18.6° (c 0.76,

22
K. Suzuki, H. Hashimoto / Carbohydrate Research 323 (2000) 14–27
2,3,4 - Tri - O - benzyl - 5 - benzyloxycarbonyl-
amino-5-deoxy-i- -arabinose (14).—A solu-
74.54, 72.80, 71.04, 70.87, 70.12, 66.18, 46.40,
D
39.02. Anal. Calcd for C41H39NO6: C, 76.73;
H, 6.13; N, 2.18. Found: C, 77.07; H, 6.06; N,
2.20.
tion of Me2SO (1.71 g, 14.96 mmol) in CH2Cl2
(5 mL) was added to a solution of (COCl)2
(951 mg, 7.48 mmol) in CH2Cl2 (50 mL) under
an argon atmosphere at −78 °C. To this mix-
ture was added after 10 min a solution of 11
(416 mg, 0.748 mmol) in CH2Cl2 (5 mL), and
then after stirring for 30 min a solution of
Et3N (1.51 g, 14.96 mmol) in CH2Cl2 (5 mL).
The mixture was diluted with CHCl3, washed
successively with satd aq NaHCO3 and water,
and dried over MgSO4. The organic layer was
concentrated, diluted with Et2O and washed
with water. The organic layer was dried
(MgSO4) and concentrated in vacuo. The
residue was purified by silica-gel column chro-
matography (5:1–3:1 hexane–EtOAc) to af-
ford 14 (392 mg, 95%) as a syrup: [h]D
2,3,4-Tri-O-benzyl-5-tert-butyloxycarbonyl-
amino-5-deoxy-i-D-arabinose
(16).—Com-
pound 16 was obtained from 13 in the same
manner as described for 14, and purified by
silica-gel column chromatography (5:1–3:1
hexane–EtOAc) to afford a syrup (90%): [h]D
1
−49.6° (c 0.84, CHCl3); H NMR (Me2SO-d6
at 373 K): l 7.41–7.28 (m, 15 H, Ph), 5.79 (d,
1 H, J1,2 3.3 Hz, H-1), 4.71–4.54 (m, 6 H,
benzyl), 4.08 (br d, 1 H, J5a,5e 14.2 Hz, H-5e),
3.93 (br s, 1 H, H-4), 3.87 (dd, 1 H, J2,3 9.2,
J3,4 3.3 Hz, H-3), 3.76 (dd, H-2), 3.09 (d,
13
H-5a), 1.41 (s, 9 H, t-Bu); C NMR (Me2SO-
d6 at 373 K): l 169.45, 153.23, 138.65, 138.55,
138.42, 127.60, 127.41, 126.96, 126.90, 126.83,
126.70, 126.56, 125.91, 78.66, 77.07, 76.28,
73.14, 71.02, 70.80, 70.23, 59.03, 27.53, 13.43.
Anal. Calcd for C31H37NO6: C, 71.65; H, 7.18;
N, 2.70. Found: C, 71.53; H, 7.27; N, 2.83.
Neopentyl 2,3,4-tri-O-benzyl-5-benzyloxy-
1
−32.2° (c 1.10, CHCl3); H NMR (Me2SO-d6
at 373 K): l 7.40–7.28 (m, 20 H, Ph), 5.86 (d,
1 H, J1,2 3.3 Hz, H-1), 5.14, 5.08 (d, 1 H, J
12.7 Hz, benzyl), 4.76–4.52 (m, 6 H, benzyl),
4.14 (dd, 1 H, J4,5e 2.3, J5a,5e 14.2 Hz, H-5e),
3.97 (br s, 1 H, H-4), 3.93 (dd, 1 H, J2,3 9.6
Hz, H-2), 3.79 (dd, 1 H, J3,4 3.5 Hz, H-3), 3.18
(d, 1 H, H-5a); 13C NMR (Me2SO-d6 at 373
K): l 154.05, 138.58, 138.46, 138.31, 136.32,
127.75, 127.62, 127.57, 127.48, 127.42, 127.15,
126.97, 126.85, 126.79, 126.74, 126.58, 76.97,
76.23, 74.70, 72.98, 71.09, 70.87, 70.35, 65.92,
39.66. Anal. Calcd for C34H35NO6: C, 73.76;
H, 6.37; N, 2.53. Found: C, 73.90; H, 6.32; N,
2.50.
carbonylamino - 5 - deoxy - i -
D
- arabinopyran-
oside (17).—To a solution of 14 (93 mg, 0.168
mmol) in pyridine (2 mL) was added Ac2O (1
mL). The mixture was concentrated and the
residue was dissolved in dry CH2Cl2 (5 mL).
To this solution was added neopentenyl alco-
,
hol (44 mg, 0.504 mmol) and 4 A molecular
sieves (100 mg), and then after 1 h, Me3SiOTf
(36×10−3 mL, 0.185 mmol), and the mixture
was stirred for 5 min at 0 °C. The reaction was
stopped by addition of a large excess of Et3N.
The solution was filtered through a Celite pad
and the filtrate evaporated in vacuo. The
residue was purified by silica-gel column chro-
matography (5:1 hexane–EtOAc) to afford 17
(104.5 mg, quant.) as a syrup: [h]D −42.8°
2,3,4-Tri-O-benzyl-5-deoxy-5-(9-fluorenyl-
methyloxycarbonylamino)-i- -arabinose (15).
D
—Compound 15 was obtained from 12 in the
same manner as described for 14, and purified
by silica-gel column chromatography (5:1–3:1
hexane–EtOAc) to afford a syrup (91%): [h]D
1
1
−27.8° (c 1.26, CHCl3); H NMR (Me2SO-d6
(c 0.30, CHCl3); H NMR (Me2SO-d6 at 373
at 373 K): l 7.87–7.26 (m, 23 H, aromatic),
5.78 (dd, 1 H, J1,2 3.5, J1,OH 4.0 Hz, H-1), 5.60
(d, 1 H, OH), 4.72–4.24 (m, 9 H, benzyl,
FmocCH2 and CH), 4.02 (br d, 1 H, J5a,5e 14.2
Hz, H-5e), 3.92 (br s, 1 H, H-4), 3.90 (dd, 1 H,
J2,3 9.4, J3,4 3.0 Hz, H-3), 3.74 (dd, H-2), 3.11
(d, H-5a); 13C NMR (CDCl3) l 154.02,
143.45, 143.31, 140.31, 138.56, 138.44, 138.29,
127.46, 127.01, 126.81, 126.74, 126.60, 126.56,
126.51, 126.47, 124.28, 119.41, 76.84, 76.32,
K): l 7.32–7.23 (m, 20 H, Ph), 5.55 (br s, 1 H,
H-1), 5.09 (br s, 2 H, benzyl), 4.73–4.51 (m,
6 H, benzyl), 4.16 (br d, 1 H, J5a,5e 14.5
Hz, H-5e), 3.97 (br s, 1 H, H-4), 3.88–3.85
(m, 2 H, H-2,3), 3.08–2.95 (m, 3 H, H-5a,
ꢀCH2-t-Bu), 0.87 (s, 9 H, t-Bu); 13C NMR
(Me2SO-d6 at 373 K): l 154.39, 138.46, 138.22,
136.14, 127.75, 127.64, 127.57, 127.44, 127.26,
127.15, 126.97, 126.83, 126.72, 126.65, 126.60,
126.56, 82.00, 77.56, 76.89, 76.07, 72.99, 71.02,

K. Suzuki, H. Hashimoto / Carbohydrate Research 323 (2000) 14–27
23
70.89, 70.41, 66.13, 31.00, 25.88, 25.70. Anal.
Calcd for C39H45NO6: C, 75.09; H,7.27; N,
2.25. Found: C, 74.84; H, 7.54; N, 2.18.
arabinopyranoside (20).—Compound 20 was
obtained from 15 in the same manner as de-
scribed for 17 using cyclohexanethiol as the
nucleophile instead of neopentyl alcohol, and
purified by silica-gel column chromatography
(3:1 hexane–EtOAc) to afford a syrup (73%,
Ethyl
2,3,4-tri-O-benzyl-5-benzyloxycar-
-arabinopyran-
bonylamino-5-deoxy-1-thio-
D
oside (18).—Compound 18 was obtained from
14 in the same manner as described for 17
using EtSH as a nucleophile instead of
neopentyl alcohol, and purified by silica-gel
column chromatography (5:1 hexane–EtOAc)
to afford a syrup quantitatively (a:b=1:3); 1H
NMR (Me2SO-d6 at 373 K): l 7.39–7.27 (m,
20 H, Ph), 5.96 (d, 0.75 H, J1,2 3.0 Hz, H-1b),
5.58 (br s, 0.25 H, H-1a), 5.18–5.07 (br s, 2 H,
benzyl), 4.76–4.49 (m, 6 H, benzyl), 4.25 (br
d, 0.75 H, J5a,5e 14.0 Hz, H-5e), 4.06 (dd, 0.75
H, J2,3 9.9, J3,4 5.3 Hz, H-3), 3.96 (br s, 0.75
H, H-4), 3.71 (dd, 0.75 H, H-2), 3.26 (d, 0.75
H, H-5a), 2.47–2.36 (m, 2 H, S-CH2CH3),
1.16 (t, 3 H, S-CH2CH3); 13C NMR (Me2SO-
d6 at 373 K): l 154.25, 138.37, 138.15, 138.04,
137.97, 137.90, 137.34, 136.05, 135.96, 127.76,
127.66, 127.58, 127.48, 127.33, 127.21, 127.08,
127.03, 126.99, 126.90, 126.83, 126.72, 126.61,
77.92, 76.98, 75.10, 73.84, 72.71, 72.15, 71.61,
71.00, 70.89, 70.61, 70.44, 69.60, 66.51, 66.36,
60.61, 58.69, 39.95, 39.34, 37.20, 25.52, 22.54,
14.25, 14.13. Anal. Calcd for C36H39NO5S: C,
72.33; H,6.58; N, 2.34. Found: C, 72.82; H,
6.35; N, 2.28.
1
a:b=1:3.1): H NMR (Me2SO-d6 at 393 K): l
7.85–7.27 (m, 23 H, aromatic), 5.76, 5.57
(broad, 1 H, H-1a and b), 4.73–4.28 (m,
benzyl and Fmoc); 13C NMR (Me2SO-d6 at
393 K): l 153.86, 143.40, 143.20, 143.11,
140.33, 138.31, 138.11, 137.95, 137.92, 137.86,
137.23, 127.50, 127.42, 127.32, 127.28, 127.24,
126.83, 126.78, 126.74, 126.69, 126.60, 126.56,
126.45, 126.40, 126.35, 126.27, 123.92, 123.83,
123.78, 119.19, 77.85, 77.04, 75.29, 73.97,
72.76, 72.20, 71.47, 70.96, 70.69, 70.39, 70.16,
69.60, 66.13, 59.91, 46.49, 46.44, 43.58, 41.33,
37.07, 33.61, 33.01, 32.85, 30.14, 24.71, 24.66,
24.55, 24.48, 24.15, 21.19, 12.89. Anal. Calcd
for C47H49NO5S: C, 76.29; H, 6.67; N, 1.89.
Found: C, 76.53; H, 6.63; N, 1.83.
Ethyl 2,3,4-tri-O-benzyl-5-tert-butoxycar-
bonylamino-5-deoxy-1-thio- -arabinopyran-
D
oside (21).—Compound 21 was obtained from
16 in the same manner as described for 18,
and purified by silica-gel column chromatog-
raphy (6:1 hexane–EtOAc) to afford a syrup
(40%, a:b=1:3.8); 1H NMR (Me2SO-d6 at 373
K): l 7.41–7.25 (m, 15 H, Ph), 5.93 (br s, 0.8
H, H-1), 4.76–4.51 (m, 6 H, benzyl), 4.21 (br
d, 0.8 H, J5a,5e 14.2 Hz, H-5e), 4.02 (dd, 0.8 H,
J2,3 9.9, J3,4 5.6 Hz, H-3), 3.95–3.91 (m, 0.8 H,
H-4), 3.69 (dd, 0.8 H, J1,2 3.1 Hz, H-2), 3.17
(d, 0.8 H, H-5a), 2.63–2.40 (m, 2 H,
SCH2CH3), 1.41 (s, 9 H, t-Bu), 1.23 (t, 3 H,
Ethyl 2,3,4-tri-O-benzyl-5-deoxy-5-(9-fluor-
enylmethyloxycarbonylamino) - 1 - thio - - ara -
D
binopyranoside (19).—Compound 19 was ob-
tained from 15 in the same manner as de-
scribed for 18, and purified by silica-gel
column chromatography (5:1 hexane–EtOAc)
1
to afford a syrup (79%, a:b=1:2.8); H NMR
(Me2SO-d6 at 393 K): l 7.87–7.22 (m, 23 H,
aromatic), 5.80–5.20 (broad, 1 H, H-1a and
b), 4.70–4.26 (m, benzyl and Fmoc); 13C
NMR (Me2SO-d6 at 393 K): l 143.51, 143.36,
143.33, 143.25, 140.45, 138.33, 138.13, 137.97,
137.85, 127.66, 127.59, 127.50, 127.42, 126.96,
126.87, 126.79, 126.72, 126.69, 126.63, 126.58,
126.49, 126.44, 124.01, 123.97, 119.37, 119.34,
77.67, 75.13, 73.84, 72.51, 71.54, 70.93, 70.26,
70.12, 69.58, 66.09, 60.40, 46.47, 39.34, 36.89,
25.59, 22.43, 14.00. Anal. Calcd for
C43H43NO5S: C, 75.30; H, 6.32; N, 2.04.
Found: C, 75.76; H, 6.20; N, 2.05.
13
SCH2CH3); C NMR (Me2SO-d6 at 373 K): l
153.33, 138.44, 138.28, 138.11, 138.08, 138.01,
137.47, 127.62, 127.57, 127.46, 127.42, 127.19,
127.08, 126.88, 126.79, 126.69, 126.61, 126.58,
118.89, 79.43, 79.23, 77.99, 77.04, 75.10, 74.04,
72.82, 72.24, 71.59, 70.87, 70.80, 70.41, 70.28,
69.53, 60.13, 58.22, 39.05, 27.53, 27.44, 27.37,
26.33, 25.54, 22.38, 14.45, 14.31. Anal. Calcd
for C33H41NO5S: C, 70.31; H, 7.33; N, 2.48.
Found: C, 69.84; H, 7.30; N, 2.53.
Cyclohexyl 2,3,4-tri-O-benzyl-5-tert-butyl-
oxycarbonylamino-5-deoxy-1-thio- -arabino-
D
pyranoside (22).—To a solution of 16 (23 mg,
41 mmol) and cyclohexanethiol (15 mmol) in
Cyclohexyl 2,3,4-tri-O-benzyl-5-deoxy-5-(9-
fluorenylmethyloxycarbonyl-amino)-1-thio- -
D

24
K. Suzuki, H. Hashimoto / Carbohydrate Research 323 (2000) 14–27
CH2Cl2 (0.5 mL) was added TsOH·H2O (7.8
mg, 41 mmol) and the mixture was stirred for
1 h at rt. The mixture was loaded on a column
of silica gel and fractionated (6:1 hexane–
EtOAc) to afford 22 (18.2 mg, 72%, a:b=
using MeOH as the nucleophile, and purified
by silica-gel column chromatography (3:1 hex-
ane–EtOAc) to afford a syrup (88%): [h]D
1
−23.1° (c 1.00, CHCl3); H NMR (Me2SO-d6
at 373 K): l 7.38–7.23 (m, 15 H, Ph), 5.39 (br
s, 1 H, H-1), 4.74–4.53 (m, 6 H, benzyl), 4.11
(br d, 1 H, J5a,5e 14.4 Hz, H-5e), 3.93 (br s, 1
H, H-4), 3.86–3.77 (m, 2 H, H-2, 3), 3.23 (s, 3
H, OMe), 2.87 (d, 1 H, H-5a), 1.41 (s, 9 H,
t-Bu); 13C NMR (Me2SO-d6 at 373 K): l
138.56, 138.46, 138.33, 127.48, 127.42, 126.83,
126.70, 126.60, 126.56, 79.16, 77.13, 75.92,
72.99, 71.31, 70.84, 70.26, 54.38, 27.44. Anal.
Calcd for C32H39NO6: C, 72.02; H, 7.37; N,
2.62. Found: C, 72.06; H, 7.72; N, 2.58.
1
1:7.3) as a syrup; H NMR (Me2SO-d6 at 373
K): l 7.53–7.36 (m, 15 H, Ph), 6.10 (br s, 0.9
H, H-1), 4.87–4.63 (m, 6 H, benzyl), 4.34 (br
d, 0.9 H, J5a,5e 14.2 Hz, H-5e), 4.16 (dd, 0.9 H,
J2,3 9.9, J3,4 5.3 Hz, H-3), 4.03 (br s, 0.9 H,
H-4), 3.81(dd, 0.9 H, J1,2 3.0 Hz, H-2), 3.36 (d,
0.9 H, H-5a), 2.78–2.61 (m, 1 H, cyclo-
hexylꢀCH), 2.17–1.31 (m, 10 H, cyclohexyl
13
CH2), 1.55 (s, 9 H, t-Bu); C NMR (Me2SO-
d6 at 373 K): l 153.08, 138.49, 138.28, 138.11,
138.08, 138.01, 127.57, 127.50, 127.41, 126.90,
126.83, 126.72, 126.63, 126.51, 79.28, 79.14,
78.13, 77.27, 75.19, 74.11, 73.01, 72.35, 71.52,
71.00, 70.78, 70.43, 70.32, 69.54, 43.54, 41.15,
39.36, 33.37, 33.27, 32.96, 27.52, 27.43, 27.37,
25.25, 25.16, 25.00, 24.89, 24.82. Anal. Calcd
for C37H47NO5S: C, 71.93; H, 7.67; N, 2.27.
Found: C, 71.73; H, 7.60; N, 2.29.
Cyclohexyl 5-amino-2,3,4-tri-O-benzyl-5-
deoxy-1-thio-i- -arabinopyranoside TFA salt
D
(25).—To a solution of 22 in CH2Cl2 (0.35
mL) was added TFA (0.7 mL). The mixture
was stirred for 22 h and concentrated to give
1
25; H NMR (CDCl3): l 7.42–7.19 (m, 15 H,
Ph), 4.82–4.31 (m, 6 H, benzyl), 4.56 (br s, 1
H, H-1), 4.11–4.08 (m, 1 H, H-4), 3.58–3.65
(m, 2 H, H-2, 3), 3.42 (dd, 1 H, J4,5e 4.6, J5a,5e
11.9 Hz, H-5e), 3.31 (dd, 1 H, J4,5a 11.6 Hz,
H-5a), 3.10 (m, 1 H, SꢀCHB), 2.28–1.18 (m,
Cyclohexyl 2,3,4-tri-O-benzyl-5-tert-butyl-
oxycarbonylamino-5-deoxy-i- -arabinopyr-
D
anoside (23).—Compound 23 was obtained
from 16 in the same manner as described for
22 using cyclohexanol as the nucleophile, and
purified by silica-gel column chromatography
(5:1 hexane–EtOAc) to afford a syrup (73%):
[h]D −33.9° (c 0.53, CHCl3); 1H NMR
(Me2SO-d6 at 373 K): l 7.34–7.27 (m, 15 H,
Ph), 5.64 (br s, 1 H, H-1), 4.72–4.52 (m, 6 H,
benzyl), 4.10 (br d, 1 H, H-5e, J5a,5e 13.9 Hz),
3.95 (br s, 1 H, H-4), 3.86 (dd, 1 H, J2,3 9.9,
J3,4 3.1 Hz, H-3), 3.77 (dd, 1 H, J1,2 3.6 Hz,
H-2), 3.39 (m, 1 H, cyclohexylꢀCH), 1.82–
1.22 (m, cyclohexylꢀCH2), 1.40 (s, 9 H, t-Bu);
13C NMR (Me2SO-d6 at 373 K): l 138.64,
138.49, 138.35, 135.38, 133.75, 130.24, 128.75,
128.48, 128.05, 128.02, 127.44, 126.88, 126.78,
126.70, 126.67, 126.58, 126.52, 118.12, 79.00,
77.15, 75.83, 73.12, 71.05, 70.80, 70.23, 56.59,
40.27, 34.76, 32.17, 30.35, 27.53, 27.44, 24.87,
24.75, 23.06, 22.92, 22.66. Anal. Calcd for
C37H47NO6: C, 73.85; H, 7.87; N, 2.33. Found:
C, 74.30; H, 7.94; N, 2.35.
13
10 H, cyclohexyl-CH2ꢀ); C NMR (CDCl3): l
135.57, 137.25, 136.48, 129.31–127.17, 77.86,
74.12, 73.80, 72.74, 72.09, 70.03, 60.04, 44.15,
42.61, 34.47, 33.01, 25.82, 25.43; HRMS
(FAB+, JMS-700MS) Calcd for C32H40NO3S
[M+H]+: 518.2731; Found: 518.2728.
5-tert-Butoxycarbonylamino-5-deoxy-i- -
D
arabinose (26).—To a methanol (43 mL) solu-
tion of 20 (1.5 g, 8.57 mmol) was added
Boc2O (3.7 g, 17.14 mmol) and 10% PdꢀC
(ꢀ 220 mg). The mixture was stirred for 24 h
under an atmosphere of hydrogen, filtered
through a Celite pad and the filtrate concen-
trated in vacuo. The residue was purified by
silica-gel column chromatography (9:1
CH2Cl2–MeOH) to afford 26 (1.25 g, 59%):
1
[h]D −21.9° (c 0.90, MeOH); H NMR (D2O)
l 5.80 (br s, 1 H, H-1), 4.10 (br s, 1 H, H-4),
4.03–3.97 (m, 1 H, H-5a), 3.90 (dd, 1 H, J2,3
10.3, J3,4 3.2 Hz, H-3), 3.81 (dd, 1 H, J1,2 3.8
Hz, H-2), 3.30(br d, 1 H, J5a,5b 13.9 Hz, H-5b),
13
Methyl 2,3,4-tri-O-benzyl-5-tert-butyloxy-
1.53 (s, 9 H, t-Bu); C NMR (D2O): l 82.56,
carbonylamino - 5 - deoxy - i -
D
- arabinopyran-
69.20, 68.32, 67.97, 27.50. Anal. Calcd for
C10H19NO6: C, 48.19; H, 7.68; N, 5.62. Found:
C, 48.09; H, 7.16; N, 5.48.
oside (24).—Compound 24 was obtained from
16 in the same manner as described for 22

K. Suzuki, H. Hashimoto / Carbohydrate Research 323 (2000) 14–27
25
Ethyl
oxy-1,6-dithio-i-
a pyridine (50 mL) solution of ethyl 2-ac-
etamido-2-deoxy-1-thio-b- -glucopyranoside
2-acetamido-3,4,-di-O-acetyl-2-de-
(dd, 1 H, J6,SH 8.6 Hz, SH), 1.29 (t, 3 H,
SCH2CH3). Anal. Calcd for C14H23NO6S2: C,
46.01; H, 6.34; N, 3.83. Found: C, 46.44; H,
6.40; N, 3.83.
D
-glucopyranoside (27).—To
D
[11] was added TsCl (6.62 g, 34.8 mmol). The
mixture was stirred for 1 h at rt. The reaction
was stopped by addition of a large excess of
MeOH. The solution was concentrated and
dried. To a pyridine (50 mL) solution of this
residue was added Ac2O (30 mL) and 4-
dimethylaminopyridine (DMAP, 177 mg, 1.45
mmol). The mixture was stirred for 12 h at rt
and concentrated. The residue was purified by
silica-gel column chromatography (1:3 hex-
ane–EtOAc) to afford 6-tosylate (4.74 g,
65%). To a DMF (5 mL) solution of the
6-tosylate (1.29 g, 2.54 mmol) was added
KSAc (581 mg, 5.08 mmol). After being
stirred for 3 h at 80 °C, the mixture was
diluted with EtOAc and washed with brine.
The organic layer was dried over (MgSO4),
and concentrated in vacuo. The residue was
purified by silica-gel column chromatography
(1:3 hexane–EtOAc) to afford 6-thioacetate
(818 mg, 79%): [h]D −25.2° (c 1.56, CHCl3);
1H NMR (CDCl3): l 5.54 (d, 1 H, J2,NH 9.57
Hz, NH), 5.13 (dd, 1 H, J2,3 9.89, J3,4 9.57 Hz,
H-3), 4.99 (dd, 1 H, J4,5 9.57 Hz, H-4), 4.54 (d,
1 H, J1,2 10.23 Hz, H-1), 4.09 (ddd, 1 H, H-2),
3.60 (ddd, 1 H, J5,6a 2.97, J5,6b 7.26 Hz, H-5),
3.27 (dd, 1 H, J6a,6b 14.18 Hz, H-6a), 3.03 (dd,
1 H, H-6b), 2.79–2.65 (m, 2 H, SCH2CH3),
2.34 (s, 3 H, SAc), 2.09, 2.03, 1.95 (each s, 9
H, OAc), 1.27 (t, 3 H, SCH2CH3). Anal. Calcd
for C16H25NO7S2: C, 47.16; H, 6.18; N, 3.44.
Found: C, 47.54; H, 6.29; N, 3.51.
Ethyl
(2,3,4 - tri - O - acetyl - 5 - tert - butoxycarbonyl -
amino - 5 - deoxy - i - - arabinopyranosyl) - 2 -
deoxy-1,6-dithio-i- -glucopyranoside (28).—
2-acetamido-3,4-di-O-acetyl-6-S-
D
D
A mixture of 26 (78.7 mg, 0.316 mmol), 27
(232.2 mg, 0.632 mmol) and TsOH·H2O (60
mg, 0.316 mmol) in CH2Cl2 was stirred for 1 h
to give a thioglycoside. After purification by
silica-gel column chromatography (9:1
CH2Cl2–MeOH), the thioglycoside was dis-
solved in pyridine (3 mL). To this mixture was
added Ac2O (1.5 mL) and DMAP (4 mg, 31.6
mmol) and stirred for 12 h at rt. The reaction
was stopped by addition of MeOH, and the
solution was concentrated in vacuo. The
residue was purified by silica-gel column chro-
matography (EtOAc) to give 28 (183 mg,
1
80%): [h]D −26.9° (c 0.20, CHCl3); H NMR
(C6D5NO2 at 393 K): l 6.45 (br d, 1 H, J1%,2%
4.6 Hz, H-1%), 6.12 (br d, 1 H, J2,NH 9.2 Hz,
NH), 5.61–5.48 (m, 4 H, H-3, 2%, 3%,4%), 5.18
(dd, 1 H, J3,4 =J4,5 9.4 Hz, H-4), 5.06 (d, 1 H,
J1,2 10.2 Hz, H-1), 4.50 (br d, 1 H, J5%a,5%e 14.8
Hz, H-5%e), 4.29 (ddd, 1 H, J2,3 9.7 Hz, H-2),
3.91 (m, 1 H, H-5), 3.70 (br d, 1 H, H-5%a),
2.99–2.79 (m, 4 H, H-6a, 6b, SCH2CH3), 2.16,
2.14, 2.12, 2.09, 2.08, 2.07 (each s, 18 H, Ac),
1.61 (s, 9 H, t-Bu), 1.36 (t, 3 H, SCH2CH3);
13C NMR (CDCl3): l 84.26 (C-1), 83.97 (C-1),
77.25 (C-5), 76.53 (C-5), 73.96, 73.62, 71.64,
71.03, 68.80, 68.53, 68.05, 67.91, 67.71, 67.19
(C-3,4,2%,3%,4%), 61.60 (C-1%), 60.95 (C-1%), 53.19
(C-2), 53.10 (C-2), 40.68 (C-5%), 39.59 (C-5%).
Anal. Calcd for C30H46N2O14S2: C, 49.85; H,
6.41; N, 3.88; S, 8.87. Found: C, 50.01; H,
6.41; N, 3.81; S, 8.62.
To a solution of 6-thioacetate (200 mg,
0.489 mmol) in MeCN (10 mL) was added
2-aminoethanethiol (45 mg, 0.587 mmol) and
stirred for 30 min at 70 °C under argon. The
reaction mixture was concentrated in vacuo
and the residue purified by silica-gel column
chromatography (1:2 hexane–EtOAc) to af-
ford 27 (172 mg, 96%): [h]D −23.2° (c 1.28,
Ethyl
bonylamino-5-deoxy-i-
2-deoxy-1,6-dithio-i- -glucopyranoside (29).
2-acetamido-6-S-(5-tert-butoxycar-
D
-arabinopyranosyl)-
D
—To a solution of 28 (109.4 mg, 0.151 mmol)
in MeOH (5 mL) was added NaOMe powder
(10 mg, 0.185 mmol). The mixture was stirred
for 1 h, neutralized with resin (Dowex 50W-
X8), filtered, and concentrated in vacuo to
give 29 (76.6 mg, 99%): [h]D −14.4° (c 1.39,
1
CHCl3); H NMR (CDCl3): l 5.51 (d, 1 H,
J2,NH 9.6 Hz, NH), 5.16 (dd, 1 H, J2,3 9.9, J3,4
9.41 Hz, H-3), 5.03 (dd, 1 H, J4,5 9.6 Hz, H-4),
4.61 (d, 1 H, J1,2 9.2 Hz, H-1), 4.10 (ddd,1 H,
H-2), 3.55 (ddd, 1 H, J5,6a 3.0, J5,6b 7.3 Hz,
H-5), 2.82–2.63 (m, 4 H, H-6a, 6b, SCH2-
CH3), 2.05, 2.03, 1.96 (each s, 9 H, OAc), 1.78
1
MeOH); H NMR (Me2SO-d6: D2O=4:1 at
373 K): l 5.57 (br d, 1 H, J1%,2% 3.6 Hz, H-1%),

26
K. Suzuki, H. Hashimoto / Carbohydrate Research 323 (2000) 14–27
Cyclohexyl 5-tert-butoxycarbonylamino-5-
deoxy-1-thio- -arabinopyranoside.—A mix-
4.42 (d, 1 H, J1,2 10.2 Hz, H-1), 1.82 (s, 3 H,
Ac), 1.39 (s, 9 H, t-Bu), 1.15 (t, 3 H,
SCH2CH3); 13C NMR (Me2SO-d6: D2O=4:1
at 373 K): l 154.66, 152.51, 133.80, 121.78,
84.10, 80.61, 80.54, 75.49, 73.86, 70.87, 68.30,
67.77, 65.59, 55.21, 43.71, 32.98, 28.27, 23.96,
22.86, 14.97. Anal. Calcd for C20H36N2O9S2:
C, 46.86; H, 7.08; N, 5.46; S, 12.51. Found: C,
45.67; H, 6.68; N, 5.49; S, 12.33.
D
ture of 26 (58 mg, 0.233 mmol) and cyclo-
hexanethiol (85×10−3 mL, 0.699 mmol) in
CH2Cl2 (3 mL) was added to TsOH·H2O (44
mg, 0.233 mmol) and stirred for 10 min at rt.
The solution was neutralized by addition of
Et3N and concentrated. The residue was
purified by silica-gel column chromatography
(3:1 hexane–EtOAc–EtOAc only) to afford
the corresponding thioglycoside (72 mg, 85%):
[h]D −64.7° (c 0.93, MeOH); 1H NMR
(Me2SO-d6: D2O=5:1 at 353 K): l 5.58 (br s,
1 H, H-1), 3.86–3.74 (m, 3 H, H-3,4,5a), 3.38
(dd, 1 H, J1,2 3.30, J2,3 9.90 Hz, H-2), 3.16 (1
H, br d, J5a,5b 13.86 Hz, H-5b), 2.56–2.49 (m,
1 H, cyclohexyl-CHB), 2.00–1.20 (m, 10 H,
cyclohexylꢀCH2ꢀ), 1.38 (s, 9 H, t-Bu); 13C
NMR (Me2SO-d6: D2O=5:1 at 353 K): l
80.24, 70.89, 68.02, 67.78, 42.41, 34.22, 33.93,
28.22, 25.99, 25.72, 25.48. Anal. Calcd for
C16H29NO5S: C, 55.31; H, 8.41; N, 4.03.
Found: C, 55.22; H, 8.30; N, 3.72.
Ethyl 2-acetamido-6-S-(5-amino-5-deoxy-
i- -arabinopyranosyl)-2-deoxy-1,6-dithio-i-
D
D-glucopyranoside TFA salt (30).—To a solu-
tion of 29 (8.4 mg, 16.3 mmol) in CH2Cl2 (0.5
mL) was added TFA (1 mL) at 0 °C and
stirred for 30 min. The mixture was stirred for
30 min at rt, and concentrated to give 30
1
quantitatively: H NMR (D2O): l 4.66 (d, 1
H, J1,2 11.0 Hz, H-1), 4.57 (br s, 1 H, H-1%),
4.17–4.09 (m, 2 H, H-2%, 4%), 3.91 (br s, 1 H,
H-3%), 3.68–3.45 (m, 4 H, H-2, 3, 4, 5), 3.34
(dd, 1 H, J4%,5%e 4.6, J5%a,5%e 12.1 Hz, H-5%e), 3.20
(d, 1 H, J6a,6b 13.5 Hz, H-6a), 3.15 (d, 1 H,
H-6b), 3.11 (dd, 1 H, J4%,5%a 10.6 Hz, H-5%a),
2.71–2.57 (m, 2 H, SCH2CH3), 1.92 (s, 3 H,
Ac), 1.15 (t, 3 H, SCH2CH3); 13C NMR
(D2O): l 174.43, 84.58, 79.10, 74.56, 70.39,
69.26, 64.32, 62.27, 54.83, 42.90, 30.07, 29.78,
25.25, 22.23, 14.51; HRMS (FAB+, JMS-
700MS) Calcd for C15H29N2O7S2 [M+H]+:
413.1418; Found: 413.1429.
5-Amino-5-deoxy- -arabinopyranose TFA
D
salt (32).—The thioglycoside just described
(72 mg) was treated with TFA (0.8 mL) in
CH2Cl2 (0.4 mL) for 30 min at 0 °C and for an
additional 30 min at rt to give the cyclohexyl
5-amino-5-deoxy-1-thio- -arabinopyranoside
D
1
TFA salt; H NMR (CF3COOD): l 5.17 (d, 1
H, J1,2 3.30 Hz, H-1), 4.70–4.63 (m, 2 H,
H-2,4), 4.30–4.04 (m, 1 H, H-3), 3.89 (br d, 1
H, J5a,5b =13.19 Hz, H-5a), 3.69 (dd, 1 H, J4,5b
6.11 Hz, H-5b), 3.11 (m, 1 H, cyclo-
hexylꢀCHꢁ), 2.08–1.37 (m, 10 H, cyclo-
hexylꢀCH2ꢀ); HRMS (FAB+, JMS-700MS)
Calcd for C11H22NO3S [M+H]+: 248.1320;
Found: 248.1307.
Ethyl 2-acetamido-2-deoxy-1,6-dithio-i- -
D
glucopyranoside (31).—A solution of 27 (90
mg, 0.244 mmol), dithiothreitol (DTT, 376
mg, 2.44 mmol), aq ammonia (28%, 6 mL)
and MeOH (1 mL) was stirred for 16 h at the
rt. The mixture was concentrated and purified
by silica-gel column chromatography (19:1
EtOAc–MeOH) to afford 31 (50 mg, 64%):
[h]D −0.3° (c 0.7, MeOH); 1H NMR
(CD3CO2D–CD3CO2Na in D2O pD=3.4
buffer): l 4.65 (d, 1 H, J1,2 10.4 Hz, H-1), 3.79
(dd, 1 H, J2,3 9.9 Hz, H-2), 3.61–3.46 (m, 3 H,
H-3, 4, 5), 3.01 (br d, 1 H, J6a,6b 14.52 Hz,
H-6a), 2.84–2.66 (m, 3 H, H-6b, SCH2CH3),
The imino sugar thioglycoside thus ob-
tained was treated in CH2Cl2–water (1:1) for
24 h, and then the water layer was concen-
trated to give the title free imino sugar as the
1
TFA salt 32 quantitatively (a:b=1.7:1); H
NMR (D2O): l 5.19 (br s, 0.4 H, H-1b), 4.62
(d, 0.6 H, J1,2 8.75 Hz, H-1a), 4.25–4.21 (m, 1
H, H-4a and H-4b), 4.00–3.99 (m, 0.8 H,
H-2b,3b), 3.87 (dd, 0.6 H, J2,3 9.74 Hz, H-2a),
3.72 (dd, 0.6 H, J3,4 3.47 Hz, H-3a), 3.45–3.19
(m, 2 H, H-5a,5b); 13C NMR (D2O): l 82.42
(C-1a), 78.86 (C-1b), 72.41 (C-3a), 71.41 (C-
2a), 69.45, 68.78 (C-2b,3b), 66.46 (C-4a),
65.51 (C-4b), 45.62 (C-5a), 42.62 (C-5b).
13
2.04 (s, 3 H, Ac), 1.27 (t, 3 H, SCH2CH3); C
NMR (CD3CO2D–CD3CO2Na in D2O pD=
3.4 buffer): l 174.36, 84.20, 80.25, 75.20,
72.40, 55.00, 25.64, 24.74, 22.32, 14.66.
HRMS (FAB+, JMS-HX110) Calcd for
C10H20NO4S2 [M+H]+: 282.0833; Found:
282.0829.

K. Suzuki, H. Hashimoto / Carbohydrate Research 323 (2000) 14–27
27
Ichikawa, J.A. Jr. Porco, C.-H. Wong, J. Am. Chem.
Soc., 113 (1991) 6187–6196.
[2] (a) L.E. Fellows, New Sci., 123 (1989) 45–48. (b) L.E.
Fellows, Chem. Br., 23 (1987) 842–844.
[3] M. Izumi, O. Tsuruta, S. Harayama, H. Hashimoto, J.
Org. Chem., 62 (1997) 992–998.
1,5-Dideoxy-1,5-imino- -erythro-pentulose
D
hydrate (33).—An acidic buffer (CD3CO2D–
CD3CO2Na–D2O buffer, pD=3.4) solution
of 32 was kept in the sample tube for 24 h to
1
gave 33 quantitatively: H NMR (CD3CO2D–
[4] (a) M. Kiso, H. Katagiri, H. Furui, A. Hasegawa, J.
Carbohydr. Chem., 11 (1992) 627–644. (b) Y. Yoshikuni,
Y. Ezure, T. Seto, K. Mori, M. Watanabe, H. Enomoto,
Chem. Pharm. Bull., 37 (1989) 106–109. (c) L.J. Liotta,
R.C. Bernotas, D.B. Wilson, B. Genam, J. Am. Chem.
Soc., 111 (1989) 783–785.
[5] P.B. Anzevano, L.J. Creemer, J.K. Daniel, C.-H.R.
King, P.S. Liu, J. Org. Chem., 54 (1989) 2539–2542.
[6] K. Suzuki, H. Hashimoto, Tetrahedron Lett., 35 (1994)
4119–4122.
[7] H. Paulsen, K. Todt, Ad6. Carbohydr. Chem., 23 (1968)
115–232.
[8] (a) P.S. Liu, J. Org. Chem., 52 (1987) 4717–4721. (b)
P.B. Anzeveno, L.J. Creemer, J.K. Daniel, C.-H.R.
King, P.S. Liu, J. Org. Chem., 54 (1989) 2539–2542. (c)
O.M. Saavedra, O.R. Martin, J. Org. Chem., 61 (1996)
6987–6993.
CD3CO2Na/D2O buffer, pD=3.4): l 4.19
(ddd, 1 H, J3,4 2.81, J4,5a 10.56 Hz, J4,5e 4.73
Hz, H-4), 3.85 (d, 1 H, H-3), 3.23 (dd, 1 H,
J5a,5e 12.21 Hz, H-5e), 3.20 (d, 1 H, J1a,1b 16.17
Hz, H-1a), 3.14 (d, 1 H, H-1b), 3.05 (dd, 1 H,
H-5a); 13C NMR (CD3CO2D–CD3CO2Na/
D2O buffer, pD=3.4): l 92.02, 71.61, 64.38,
64.31, 42.57. HRMS (FAB+, JMS-HX110)
Calcd for C5H12O4N [M+H]+: 150.0766;
Found: 150.0761.
[9] A.I. Mancuso, S.-L. Huang, O. Swern, J. Org. Chem., 43
(1978) 2480–2482.
Acknowledgements
[10] B.M. Pinto, R.Y.N. Leung, in: G.R.Y. Thatcher (Ed.),
The Anomeric Effect and Associated Stereoelectronic Ef-
fects, ACS Symp. Ser., 539 (1993) 126–155.
[11] (a) R.U. Lemieux, A.R. Morgan, Can. J. Chem., 43
(1965) 2205–2213. (b) R.U. Lemieux, Pure Appl. Chem.,
25 (1971) 527–548.
This work was supported in part by a
Grant-in-Aid (No. 06453212) for Scientific
Research on Priority Area from the Japanese
Ministry of Education, Science, Sports and
Culture.
[12] L. Hough, M.I. Taka, J. Chem. Soc., 35 (1994) 2042–
2048.
[13] J.S. Andrews, T. Weimer, T.P. Frandsen, B. Svensson,
B.M. Pinto, J. Am. Chem. Soc., 117 (1995) 10799–10804.
[14] (a) A.H. Siriwardena, A. Chiaroni, C. Riche, D.S. Grier-
son, J. Org. Chem., 57 (1992) 5661–5666. (b) J. Radom-
ski, A. Temeriusz, Carbohydr. Res., 187 (1989) 223–237.
[15] H. Hashimoto, M. Izumi, Tetrahedron Lett., 34 (1993)
4949–4952.
References
[1] (a) M.P. Dale, H.E. Ensley, K. Kern, K.A. Sastry, D.
Byers, Biochemistry, 24 (1985) 3530–3539. (b) T. Kaji-
moto, K.K.-L. Liu, R.L. Pederson, Z. Zhong, Y.
.