Synthesis of α-glucosidase inhibitors: Kojibiose-type pseudodisaccharides and a related pseudotrisaccharide

Article abstract of DOI:10.1016/S0008-6215(98)00045-7

Two kojibiose-type pseudo-disaccharides and a trisaccharide, containing a 5-amino-1,2,3,4-cyclopentanetetrol derivative or valienamine, linked by way of nitrogen bridges to the sugar residues, have been designed and synthesized as processing α-glucosidase I inhibitors. Synthesis of the pseudodisaccharides was carried out starting from the coupling products of the sugar isothiocyanates and an aminocyclitol, respectively, by cyclization with mercury(II) oxide to the cyclic isoureas and subsequent deprotection. Pseudokojibiose was prepared in a poor yield by reaction of a protected valienamine and a sugar epoxide, followed by deprotection. Although the pseudooligosaccharides are all strong inhibitors of α-glucosidase (baker's yeast), they did not have any inhibitory potency against either sucrase isomaltase (rat Intestine) or processing α-glucosidase (rat liver microsomes).

Full text of DOI:10.1016/S0008-6215(98)00045-7

370
Carbohydrate Research 370 (1998) 83±95
Synthesis of ꢀ-glucosidase inhibitors: kojibiose-
type pseudodisaccharides and a related
pseudotrisaccharide1
Seiichiro Ogawa *, Makoto Ashiura, Chikara Uchida
Department of Applied Chemistry, Faculty of Science and Technology, Keio University, Hiyoshi,
Kohoku-ku, Yokohama 223-8522, Japan
Received 24 October 1997; accepted 26 January 1998
Abstract
Two kojibiose-type pseudo-disaccharides and a trisaccharide, containing a 5-amino-1,2,3,4-
cyclopentanetetrol derivative or valienamine, linked by way of nitrogen bridges to the sugar resi-
dues, have been designed and synthesized as processing ꢀ-glucosidase I inhibitors. Synthesis of the
pseudodisaccharides was carried out starting from the coupling products of the sugar iso-
thiocyanates and an aminocyclitol, respectively, by cyclization with mercury(II) oxide to the cyclic
isoureas and subsequent deprotection. Pseudokojibiose was prepared in a poor yield by reaction of
a protected valienamine and a sugar epoxide, followed by deprotection. Although the pseudooli-
gosaccharides are all strong inhibitors of ꢀ-glucosidase (baker's yeast), they did not have any
inhibitory potency against either sucrase isomaltase (rat intestine) or processing ꢀ-glucosidase (rat
liver microsomes). # 1998 Elsevier Science Ltd. All rights reserved
Keywords: Pseudooligosaccharides; Carbaoligosaccharides; Carbohydrate mimics; ꢀ-Glucosidase inhibitors;
Glycoprotein-processing glucosidase I inhibitors
1. Introduction
Based on these results, a number of N-substituted
deoxynojirimycins, including the N-butyl derivative
(N-butyl DNJ), have so far been tested as potential
anti-HIV compounds [6]. Recently, studies on the
elucidation of structure±activity relationships of
derivatives of the trehalase inhibitor, trehazoline
[7], have led to a development of highly potent ꢀ-
glucosidase inhibitors composed of cyclic isourea
derivatives of certain stereoisomers of 5-amino-1-
(hydroxymethyl)-1,2,3,4-cyclopentanetetrols2 hav-
ing N-substituted cyclic isourea functions [8]. In
particular, N-butyl cyclic isourea [9] of the 1l-
(1,2,4,5/3) isomer has been shown to possess a
Trimming of glucose residues on the oligo-
saccharide moiety of human immunode®ciency
virus (HIV) glycoprotein is crucial for HIV infec-
tion, and processing glucosidase inhibitors have
been found to exhibit anti-HIV in vitro [2±5].
* Corresponding author. Fax: 0081 045 563 0446.
1
Pseudosugars, Part 38: For Part 37, see ref. [1].
In this paper, nomenclature of pseudooligosaccharides
2
follow IUPAC and IUB 1996 recommendations for carbohy-
drates (Pure Appl. Chem., 68 (1996) 1919±2008; Carbohydr.
Res., 297 (1997) 1±92) and 1973 recommendations for cyclitols
(Pure Appl. Chem., 37 (1974) 285±297).
0008-6215/98/$19.00 # 1998 Elsevier Science Ltd. All rights reserved
PII S0008-6215(98)00045-7

84
S. Ogawa et al./Carbohydrate Research 370 (1998) 83±95
Compounds 3 and 4 have cyclic isourea derivatives
as their nonreducing moieties. In addition, pseudo-
kojibiose 5, containing unsaturated carba-amino
sugar valienamine [12] in place of the nonreducing
glucopyranose residue, i.e., the analog of the
strong ꢀ-glucosidase inhibitor methyl acarviosin
[13], was designed to compare its activity favorably
to that of 3 (Scheme 2).
2. Results and discussion
Synthesis of methyl ꢀ-kojibioside mimic 3, the
nonreducing ꢀ-glucopyranose residue being
replaced by the N-linked cyclic isourea moiety
composed of 5-amino-1-C-(hydroxymethyl)-1,2,3,4-
cyclopentanetetrol, was carried out by coupling of
a newly prepared sugar isothiocyanate 10 and the
aminocyclitol [7,8] 18, and cyclization of the
resulting thiourea in the presence of yellow mer-
cury(II) oxide [7,14], followed by deprotection.
Alternatively, the trisaccharide analogue 4 was
prepared similarly from new disaccharide iso-
thiocyanate 17 and 18.
First, starting from known 1,6-anhydro-2-azido-
4-O-benzyl-2-deoxy-ꢁ-d-glucopyranose [15,16] (6),
two sugar isothiocyanates 10 and 17 were prepared.
Thus, methanolysis of 6 with methanolic hydro-
chloric acid proceeded very slowly to give poor
yields of methyl ꢀ- (7, 16%) and ꢁ-glucopyranoside
derivatives (8, 10%), together with 6 recovered
(62%). Conversion to the methyl glucosides would
be improved by mainitaining the concentration of
hydrochloric acid under prolonged reaction time.
The ꢀ-anomer was benzylated with benzyl bromide
and sodium hydride in DMF to give the known
tribenzyl ether 9 [17,18] (93%), which was reduced
with hydrogen sul®de in aq pyridine and subse-
quently treated with 1,10-thiocarbonyldiimidazole
[19] in dichloromethane at room temperture to give
crystalline isothiocyanate 10 (93%). On the other
Scheme 1.
high inhibitory potential against both ꢀ-glucosi-
dase (baker's yeast) and glucosidase I (yeast) (IC50
4.2Â10 6 M) [10], being almost comparable to N-
butyl DNJ. In the examination of the potentials of
pseudoamino sugars (valiolamine, valienamine,
etc.) as processing glucosidase inhibitors [11], koji-
biose has been shown to be a moderate inhibitor of
glucosidase I (rat liver microsomes). This suggested
that kojibiose-type pseudodisaccharides would act
as transition-state analogues of these enzymes.
Thus, pseudo di- and trisaccharides, composed of
the N-(2-deoxy-ꢀ-d-glucos-2-yl) cyclic isoureas of
5-amino-1-(hydroxymethyl)-1,2,3,4-cyclopentane-
tetraol, were chosen to improve hopefully the spe-
ci®city of the inhibitory potential against glucosidase
I. In this study, three pseudooligosaccharides 3, 4,
and 5 have been designed, as processing glucosidase
inhibitors, to mimic the terminal sequence di- and
trisaccharide portions of the N-glycan tetra-
decasaccharide chain Glc3 Man9GlcNAc2: ꢀ-d-glu-
copyranosyl-(1!2)-ꢀ-d-glucopyranose (1) and ꢀ-d-
glucopyranosyl-(1!2)-ꢀ-d-glucopyranosyl-(1!3)-
ꢀ-d-glucopyranose (2) (Scheme 1).
Scheme 2.

S. Ogawa et al./Carbohydrate Research 370 (1998) 83±95
85
hand, acetolysis of the dibenzyl ether obtained [16]
from 6 gave the diacetate 11 (ꢀ100%), which was
treated with titanium tetrabromide [16] in chloro-
form containing acetic acid, giving a 57% yield of
an anomeric mixture of the 6-acetate 12. Com-
pound 12 was then converted in the conventional
manner [20] into the ꢁ-trichloroacetimidate 13
(68%). Condensation of 13 with methyl 2,4,6-tri-
O-benzyl-ꢀ-d-glucopyranoside [21] 14 using tri-
methylsilyltri¯uoromethanesulfonate in diethyl
ether [20] gave the disaccharide derivative 15
79% of the cyclic isoureas 20 and 21. The mixture
was reduced under Birch conditions, and the free
bases 3 and 22 were subsequently acetylated to
give, after separation by chromatography on silica
gel column, the octa-N,O-acetyl derivatives 23
(53%) and 24 (9%) of the cyclic isoureas. Judging
1
from the H NMR data of 23 and 24, they are
considered to be single compounds, respectively,
but there are no data to determine which isomeric
form (syn- or anti-giometrical structure) they
adopt. The product ratio seemed to largely depend
on a stablity of the isomeric free bases 3 and 22
interconvertible under neutral to basic conditions.
In general, the tautomers containing a tertiary
hydroxyl in the ring are more stable [7]. Zemplen
1
(84%), the H NMR spectrum of which revealed a
doublet (ꢂ 5.46, J 3.7 Hz) due to H-10, supporting
the ꢀ-glucopyranoside structure. Zemplen O-dea-
cylation [22] of 15, followed by benzylation, gave
the hexabenzyl ether 16 in 65% yield. The azido
group was reduced, and the resulting amine was
similarly converted into the isothiocyanate 17
(94%) (Scheme 3).
ꢁ
N,O-deacylation [22] of 23 at 15 C, followed by
puri®cation on a column of Dowex-50WÂ2 (H+)
resin with 0.5 M aqueous ammonia, a€orded 3 in
85% yield. Similar deacylation of 24 gave only 3
instead of 22. Compound 3 is spectroscopically a
single compound, no data being available to deter-
mine whether there exists the stable tautomer with
regards to the position of unsaturation or a rapid
interconversion between two possible tautomers
(Scheme 4).
Coupling of the sugar isothiocyanates 10 and
17 with 1l-(1,2,4,5/3)-5-amino-1-hydroxymethyl-
1,2,3,4-cyclopentanetetrol [7] (18) was conducted
essentially similar to the preparation [7] of treha-
zolin derivatives. Thus,
a
mixture of 10
(0.28 mmol) and the aminocyclitol 18 (0.23 mmol)
in aqueous 75% DMF was allowed to react for
21 h at room temp, giving the thiourea 19 (97%),
which was then treated with excess of mercury(II)
oxide in 1:6 acetone±diethyl ether to give rise to a
Similar coupling of molar equivalents of 17 and
18 gave the thiourea 25 (76%), which was cyclized
by treatment with mercury(II) oxide to a€ord the
isomeric mixture of cyclic isoureas 26 and 27, Birch
Scheme 3.
3
For the nomenclature of valienamine, an unsaturated
5a-carba-amino sugar, see ref. [24].

86
S. Ogawa et al./Carbohydrate Research 370 (1998) 83±95
Scheme 4.

S. Ogawa et al./Carbohydrate Research 370 (1998) 83±95
87
reduction of which gave, after subsequent acetylation
and isolation, the undeca-N,O-acetyl derivative 28
(16%). The free base 4 (93%) was generated from 28.
The disaccharide mimic 5, containing valiena-
mine moiety linked by way of an imino bridge, was
initially prepared as a minor diequatorial opening
product by condensation of the sugar epoxide [23]
32 and di-O-isopropylidenevalienamine [2,3:4,6-di-
O-isopropylidene-5a-carba-xylo-hex-5(5a)-enopyr-
anosylamine3] [25] 29. In order to improve a yield
of desired diequatorial opening products of the
nucleophilic substitution reaction between 29 and
methyl 2,3-anhydro-ꢀ-d-mannopyranoside [26] 31,
two protected compounds, the 4,6-O-benzylidene
[23] 30 and 4,6-di-O-benzyl derivatives [27] 32,
were subjected to ꢁa coupling reaction with 29 in
2-propanol at 120 C. Reaction of 29 and 30 or 31
a€orded exclusively a single positional isomer the
diaxially opened product with the d-altro-con®g-
uration in high yields. However, when the dibenzyl
ether 32 was used, the desired minor product 36
was obtained in 6% yield, along with the major
isomer 33 (66%). The structure of 33 was con-
aziridine 39 (95%). Reaction of 39 with sodiꢁum
acetate in 80% aq acetic acid for 3 days at 90 C,
followed by acetylation, produced about a 4:5
mixture of 40 and 41 (diculty separable) in 74%
yield. The mixture was O-deacetylated, and the
products were separated by preparative TLC to
give the dibenzyl ether 37 (32%) as the only pure
compound, which was identical to the compound
obtained from 36 by O-deisopropylidenation.
Birch reduction of 37 and puri®cation by the resin
column a€orded the targeted compound 5 (78%)
as a hygroscopic powder. The structure was con-
1
®rmed by the H NMR spectrum of its heptaace-
tate 38 (Scheme 6).
Biological assay.ÐCompounds 3, 4, and 5 were
®rst assayed for inhibitory activity against ꢀ-glu-
cosidase (Baker's yeast). The former two contain-
ing a cyclic isourea moiety have been shown to be
very strong inhibitors (Table 1). The inhibitory
potential of 3 is almost comparable to that of the
respective N-phenyl cyclic isourea [9,10]. The cor-
responding valienamine analogue 5 shows about
250-fold lower activity, conceibably demonstrating
that the cyclic isourea derivative of 18 more
resembles in these cases the half-chair transition
state postulated during hydrolysis of ꢀ-glucosides.
However, all compounds did not possess any inhi-
bitory activity against both maltase (porcine) and
processing glucosidase I (rat liver microsomes) [30].
They should surely be tested for other processing
glycosidases from di€erent species in future. The
present results suggested that design of the transi-
tion-state mimicking would not always lead to a
®nding an inhibitor of processing glucosidase.
1
®rmed by the H NMR spectrum of the O-acetyl
derivative 34 conventionally derived from it. Con-
ventional acetylation of valienamine derivatives
related to validoxylamine [28] or methyl acarviosin
[29] did not give rise to the corresponding N-acetyl
derivatives, probably due to steric hindrance
(Scheme 5).
Then, attempts were made to transform 33 into
36 via an aziridine derivative. Thus, conventional
mesylation of 33 gave the mesylate 35, which was
ꢁ
treated with DBU in toluene at 60 C to give the
Scheme 5.

88
S. Ogawa et al./Carbohydrate Research 370 (1998) 83±95
Scheme 6.
ꢁ
3. Experimental
(3 mL) with acetyl chloride (0.5 mL) at 0 C, was
added 1,6-anhydro-2-azido-4-O-benzyl-2-deoxy-ꢁ-d-
glucopyranose [16] (6, 84 mg, 0.30 mmol), and the
mixture was stirred for 18 h at 60 ꢁC. The mixture was
neutralized with triethylamine and then evaporated.
The products were chromatographed on silica gel (9 g,
1:3 ethyl acetate±toluene) to give the ꢁ-glucoside 8
(9.4 mg, 10%) and the ꢀ-glucoside 7 (15 mg, 16%) as
crystals, together with 6 (52 mg) that was recovered.
General methods.ÐMelting points were deter-
mined with a Mel-Temp capillary melting-point
apparatus and are uncorrected. Optical rotations
were measured with a Jasco DIP-370. IR spectra
were recorded with Jasco IR-810 or Hitachi Bio-
Rad Degilab FTS-65. 1H NMR spectra were
recorded for solutions in CDCl3 (internal Me4Si)
with a Jeol JNM GSX-270 ft (270 MHz) instrument.
TLC was performed on Silica Gel 60 GF (E.
Merck, Darmstadt) with detection by charring with
concd H2SO4. Column chromatography was con-
ducted on Wakogel C-300 (silica gel, 300 Mesh,
Wako Chemical, Osaka). Organic solutions were
dried over anhyd Na2SO4, and evaporated at <50
ꢁC under diminished pressure.
For compound 7: mp 97±98 ꢁC (from ethyl
21
d
acetate); Rf 0.25 (1:3 ethyl acetate±toluene); [ꢀŠ
+147ꢁ (c 1.2, CHCl3); IR (neat): ꢃ 3500 (OH) and
1
1
2100 cm (N3); H NMR (CDCl3): ꢂ 7.42±7.25 (5
H, m, Ph), 4.80 and 4.75 (ABq, Jgem 11.7 Hz,
PhCH2), 4.77 (d, 1 H, J1,2 3.7 Hz, H-1), 4.09 (dd, 1
H, J2,3 10.3, J3,4 8.8 Hz, H-3), 3.85 (dd, 1 H, J5,6a
2.9, J6gem 12.1 Hz, H-6a), 3.77 (dd, 1 H, J5,6b
3.7 Hz, H-6b), 3.66 (ddd, 1 H, J4,5 9.9, H-5), 3.46
(dd, 1 H, H-4), 3.40 (s, 3 H, Me), 3.22 (dd, 1 H, H-
2). Anal. Calcd for C14H19N3O5: C, 54.36; H, 6.19;
N, 13.58. Found: C, 54.30; H, 6.20;ꢁN, 13.67.
Methyl 2-azido-4-O-benzyl-2-deoxy-a- (7) and b-
d-glucopyranosides (8).ÐTo methanolic hydro-
chloric acid, prepared by treatment of methanol
For compound 8: mp 140±141 C (from etha-
Table 1
Inhibitory activity against three enzymes a
25
d
nol); Rf 0.31 (1:3 ethyl acetate±toluene); [ꢀŠ
14ꢁ
(c 1.1, CHCl3); IR (neat): ꢃ 3350 (OH) and
2110 cm 1 (N3); 1H NMR (CDCl3): ꢂ 7.42±7.25 (m,
5 H, Ph), 4.82 and 4.73 (ABq, Jgem 11.4 Hz,
PhCH2), 4.24 (d, 1 H, J1,2 8.1 Hz, H-1), 3.91 (dd, 1
H, J5,6a 2.6, J6gem 12.1 Hz, H-6a), 3.77 (dd, 1 H,
J5,6b 4.0 Hz, H-6b), 3.57 (s, 3 H, Me), 3.55±3.47 (m,
2 H, H-3, 4), 3.27 (dd, 1 H, J2,3 9.9 Hz, H-2). Anal.
Found: C, 54.10; H, 6.24; N, 13.37.
Compound ꢀ-Glucosidase
(baker's yeast) b
[IC50 (M)]
Sucrase and
isomaltase
Processing
glucosidase
(Rat intestine) c (Rat liver
microsomes) d
8
3
4
5
1.2Â10
1.8Â10
3.1Â10
NI
NI
NI
NI
NI
NI
7
6
a NI: No inhibitory activity was observed.
b Substrate: p-Nitrophenyl ꢀ-d-glucopyranoside.
c Substrate: Maltose.
Methyl 2-azido-3,4,6-tri-O-benzyl-2-deoxy-a-d-
glucopyranoside (9).ÐTo a solution of 7 (478 mg,
d Substrate: Glc3Man9GlcNAc2.

S. Ogawa et al./Carbohydrate Research 370 (1998) 83±95
89
ꢁ
1.55 mmol) in DMF (10 mL) was added at 0 C
sodium hydride (250 mg, 6.2 mmol) followed by
benzyl bromide (550 ꢄL, 4.6 mmol), and the mix-
ture was then stirred for 3 h at room temp. The
mixture was processed in the conventional manner.
The crude product was chromatographed on silica
gel (40 g, 1:9 ethyl acetate±hexane) to give 9
chloroform (2.2 mL), was added titanium tetra-
bromide (193 mg, 0.527 mmol), and the mixture
was stirred for 12 h at room temp. The mixture was
diluted with chloroform (50 mL), washed with
saturated aq NaHCO3, dried, and evaporated. The
residue was dissolved in acetone (2 mL), and the
solution was treated with silver carbonate (107 mg,
0.386 mmol) and water (7 ꢄL, 0.386 mmol) for 1.5 h
at room temp. The mixture was ®ltered through a
Celite bed, and the ®ltrate was diluted with ethyl
acetate (30 mL), washed with water, dried, and
evaporated. The residue was chromatographed on
silica gel (6.5 g, 1:5 ethyl acetate±hexane) to give a
ca. 3:2 mixture 12 of the inseparable ꢀ- and ꢁꢁ-
anomers (85 mg, 57%) as a solid: mp 102±105 C
(from ethyl acetate); IR (neat): ꢃ 3400 (OH), 2100
(N3), and 1710 cm 1 (ester); 1H NMR (CDCl3): for
ꢀ-anomer: ꢂ 7.41±7.22 (m, 10 H, 2ÂPh), 5.29 (d, 1
H, J1,2 3.7 Hz, H-1), 4.92 and 4.88, and 4.92 and
4.82 (2ÂABq, Jgem 10.6 Hz, 2ÂPhCH2), 4.34 (dd, 1
H, J5,6a 2.2, Jgem 12.1 Hz, H-6a), 4.21 (dd, 1 H,
J5,6b 4.4 Hz, H-6b), 4.11 (ddd, 1 H, J4,5 9.9 Hz, H-
5), 4.04 (dd, 1 H, J2,3 10.3, J3,4 8.8 Hz, H-3), 3.55
(dd, 1 H, H-4), 3.43 (dd, 1 H, H-2), 2.04 (s, 3 H,
Ac); for ꢁ-anomer: ꢂ 7.41±7.22 (m, 10 H, 2ÂPh),
4.88 and 4.60 (ABq, Jgem 9.5 Hz, PhCH2), 4.86 and
4.58 (ABq, Jgem 10.6 Hz, PhCH2), 4.59 (s, 1 H, J1,2
9.2 Hz, H-1), 4.36 (dd, 1 H, J5,6a 1.5, J6gem 12.1 Hz,
H-6a), 4.18 (dd, 1 H, J5,6b 7.7 Hz, H-6b), 3.57±
3.45 (m, 2 H, H-4,5), 3.47 (dd, 1 H, J2,3 9.2, J3,4
9.2 Hz, H-3), 3.39 (dd, 1 H, J1,2 9.2 Hz, H-2), 2.03
(s, 3 H, Ac). Anal. Calcd for C22H25N3O6: C,
61.82; H, 5.90; N, 9.83. Found: C, 62.11; H, 6.02;
N, 9.53.
1
(704 mg, 93%) as a syrup: H NMR (CDCl3): ꢂ
7.20±7.15 (m, 15 H, 3ÂPh), 4.88 and 4.84 (ABq,
Jgem 11.0 Hz, PhCH2), 4.82 (d, 1 H, J1,2 3.3 Hz, H-
1), 4.80 and 4.51, and 4.63 and 4.48 (ABq, Jgem
11.0 Hz, 2ÂPhCH2), 3.97 (dd, 1 H, J2,3 10.3, J3,4
8.4 Hz, H-3), 3.81±3.64 (m, 4 H, H-4,5,6), 3.44
(dd, 1 H, H-2), 3.42 (s, 3 H, Me). The spectral
data were shown to be partly identical to those
reported for an authentic sample [17]. This com-
pound was used in the next step without further
puri®cation.
Methyl 3,4,6-tri-O-benzyl-2-deoxy-2-isothiocyan-
ato-a-d-glucopyranoside (10).ÐH2S was intro-
duced into a solution of crude 9 (331 mg,
0.677 mmol) in a mixture of pyridine (8 mL) and
water (4 mL) for 7 h at room temperature, and then
the mixture was purged with N2 for 30 min. The
mixture was evaporated to dryness, and the residue
was chromatographed on silica gel (16 g, toluene !
1:6 ethanol±toluene) to give a crude amine (ꢀ300
mg). The amine was dissolved in dichloromethane
(6 mL), and the solution was treated with 1,10-
thiocarbonyldiimidazole (347 mg, 1.95 mmol) for
1.5 h at room temp and then evaporated. The resi-
dual product was chromatographed on silica gel
(18 g, 1:10 ethyl acetate±hexane) to give 10
ꢁ
(317 mg, 92.7%) as crystals: mp 75±77 C (from
+
164ꢁ (c 0.77, CHCl3); IR (neat): ꢃ 2075 cm
22
d
hexane); Rf 0.63 (1:4 ethyl acetate±hexane); [ꢀŠ
6-O-Acetyl-2-azido-3,4-di-O-benzyl-b-d-glucopyr-
anose trichloroacetimidate (13).ÐTo a solution of
12 (63 mg, 0.15 mmol) in dichloromethane (2 mL)
were added potassium carbonate (100 mg,
0.74 mmol, 5 molar equiv) and trichloroacetonitrile
(60 ꢄL, 0.6 mmol, 4 molar equiv), and the mixture
was stirred for 7 h at room temp. The mixture was
then ®ltered through a Celite bed, and the ®ltrate
was evaporated to dryness. The residue was chro-
1
1
(N=C=S); H NMR (CDCl3): ꢂ 7.41±7.12 (m, 15
H, 3ÂPh), 4.90 and 4.83 (ABq, Jgem 11.0 Hz,
PhCH2), 4.61 and 4.48 (ABq, Jgem 12.1 Hz,
PhCH2), 3.98 (dd, 1 H, J2,3 9.9, J3,4 8.8 Hz, H-3),
3.82±3.79 (m, 1 H, H-5), 3.75 (dd, 1 H, J1,2 3.3 Hz,
H-2), 3.74 (dd, 1 H, J5,6a 3.7, J6gem 10.7, H-6a),
3.64 (dd, 1 H, J5,6b 1.9 Hz, H-6b), 3.63 (dd, 1 H,
J4,5 9.9 Hz, H-4), 3.43 (s, 3 H, Me). Anal. Calcd for
C29H31NO5S: C, 68.90; H, 6.18; N, 2.77. Found: C,
68.85; H, 6.16; N, 3.06.
matographed on silica gel (8 g, 1:8 ethyl acetate±
24
hexane) to give 13 (58 mg, 68%) as a syrup, [ꢀŠ
d
+6.8ꢁ (c 1.5, CHCl3); IR (neat): ꢃ 2110 (N3) and
1
1
6-O-Acetyl-2-azido-3,4-di-O-benzyl-2-deoxy-d-
glucopyranose (12).ÐTo a solution of a mixture
(11, 164 mg, 0.351 mmol) of 6-O-acetyl-2-azido-3,4-
di-O-benzyl-2-deoxy-ꢀ- and ꢁ-d-glucopyranose
acetates, prepared from 6 according to the proce-
dure of Paulsen and Stenzel [16] in 1:10 acetic acid±
1740 cm (ester); H NMR (CDCl3): ꢂ 7.40±7.25
(m, 10 H, 2ÂPh), 5.62 (d, 1 H, J1,2 8.4 Hz, H-1),
4.94 and 4.85 (ABq, Jgem 10.6 Hz, PhCH2), 4.85
and 4.59 (ABq, Jgem 11.0 Hz, PhCH2), 4.32 (dd, 1
H, J5,6a 1.3, J6gem 12.1 Hz, H-6a), 4.23 (dd, 1 H,
J5,6b 3.7 Hz, H-6b), 3.69 (dd, 1 H, J1,2 8.4, J2,3

90
S. Ogawa et al./Carbohydrate Research 370 (1998) 83±95
9.5 Hz, H-2), 3.64±3.55 (m, 2 H, H-4,5), 3.60 (dd, 1
H, J3,4 9.9 Hz, H-3), 2.02 (s, 3 H, Ac).
+56ꢁ (c 0.89, CHCl3); IR (neat): ꢃ 2110 (azide)
cm ; H NMR (CDCl3): ꢂ 7.38±7.09 (m, 30 H,
1
1
6ÂPh), 5.52 (d, 1 H, J1 ,2 3.7 Hz, H-10), 4.91 and
4.50 (ABq, Jgem 11.6 Hz, CH2Ph), 4.90 and 4.86
(ABq, Jgem 11.7 Hz, CH2Ph), 4.75 and 4.45 (ABq,
Jgem 11.4 Hz, CH2Ph), 4.71 (d, 1 H, J1,2 3.7 Hz, H-
1), 4.65 and 4.29 (ABq, Jgem 12.1 Hz, CH2Ph), 4.59
and 4.52 (ABq, Jgem 11.4 Hz, CH2Ph), 4.56 and
4.51 (ABq, Jgem 12.1 Hz, CH2Ph), 4.27±4.21 (m, 1
H, H-50), 4.16 (dd, 1 H, J2,3 9.9, J3,4 8.1 Hz, H-3),
0
0
Methyl 6-O-acetyl-2-azido-3,4-di-O-benzyl-2-
deoxy-a-d-glucopyranosyl-(1!3)-2,4,6-tri-O-ben-
zyl-a-d-glucopyranoside (15).ÐA mixture of 13
(149 mg, 0.26 mmol) and methyl 2,4,6-tri-O-benzyl-
ꢀ-d-glucopyranoside [21] (14, 242 mg, 0.52 mmol) in
diethyl ether (8 mL) was stirred in the presence of
4A molecular sieves (150 mg) under nitrogen forꢁ1 h
at room temp. The mixture was cooled to 15 C,
and 0.01M trimethylsilyl tri¯uoromethanesulfonate
(2.6 ꢄL, 0.026 mmol, 0.1 molar equiv) was added,
and the mixture was stirred for 45 min at the same
temp. After neutralization with sodium hydro-
gencarbonate, the mixture was ®ltered and the
®ltrate was evaporated. The residue was chroma-
tographed on silica gel (22 g, 1:17 ethyl acetate±
3.98 (dd, 1 H, J2 ,3 10.3, J3 ,4 8.8 Hz, H-30), 3.81±
3.64 (m, 5 H, H-4,5,6,40), 3.51 (dd, 1 H, J1,2 3.7 Hz,
H-2), 3.42±3.36 (m, 2 H, H-60), 3.35 (s, 3 H, OMe),
3.34 (dd, 1 H, H-20). Anal. Calcd for C55H59N3O10:
C, 71.64; H, 6.45; N, 4.56. Found: C, 71.65; H,
6.47; N, 4.54.
0
0
0
0
Methyl 3,4,6-tri-O-benzyl-2-deoxy-2-isothiocyan-
ato-a-d-glucopyranosyl)-(1!3)-2,4,6-tri-O-benzyl-
a-d-glucopyranoside (17).ÐH2S was slowly bub-
bled into a solution of the azide 16 (95 mg,
0.103 mmol) in 4:2:1 pyridine±water±triethylamine
(5 mL) for 7 h at room temp. After purging the
solution of H2S with nitrogen for half an hour, the
mixture was evaporated, and the residue was
roughly chromatographed on a silica gel column
(8 g, toluene ! 1:20 ethanolÐtoluene). The crude
amine obtained was dissolved in dichloromethane,
and the resulting solution was treated with 1,10-
thiocarbonyldiimidazole (55.2 mg, 0.31 mmol) for
4 h at room temperature. The reaction mixture was
evaporated, and the residue was chromatographed
on a silica gel (9 g, 1:5 ethyl acetate±hexane) to give
toluene) to give 15 (191 mg, 84%) as a syrup: Rf
25
d
0.42 (1:5 ethyl acetate±toluene); [ꢀŠ +48ꢁ (c 0.88,
CHCl3); IR (neat): ꢃ 2100 (azide) and 1740 (ester)
1
1
cm ; H NMR (CDCl3): ꢂ 7.40±7.15 (m, 25 H,
5ÂPh), 5.46 (d, 1 H, J1 ,2 3.7 Hz, H-10), 4.89 and
4.53 (ABq, Jgem 10.6 Hz, CH2Ph), 4.89 (s, 2 H,
CH2Ph), 4.80 and 4.51 (ABq, Jgem 11.0 Hz,
CH2Ph), 4.59 and 4.52 (ABq, Jgem 11.7 Hz,
CH2Ph), 4.38 (m, 1 H, H-50), 4.14 (dd, 1 H, J2,3 9.6,
0
0
0
0
0
J3,4 8.1 Hz, H-3), 4.12 (dd, 1 H, J5 ,6 a 2.2, J6 gem
0
12.1 Hz, H-60a), 3.97 (dd, 1 H, J2 ,3 10.3, J3 ,4
8.8 Hz, H-30), 3.89 (dd, 1 H, J5 ,6 b 3.7 Hz, H-60b),
3.80±3.63 (m, 4 H, H-4,5,6), 3.52 (dd, 1 H, J1,2 3.7,
0
0
0
0
0
0
0
J2,3 9.6 Hz, H-2), 3.51 (dd, 1 H, J4 ,5 10.3 Hz, H-4 ),
0
0
0
3.34 (s, 3 H, OMe), 3.31 (dd, 1 H, J1 ,2 3.7 Hz, H-
20), 2.00 (s,
H, Ac). Anal. Calcd for
3
the isothiocyanate 17 (90 mg, 94%) as a colorless
25
d
C50H55N3O11: C, 68.71; H, 6.34; N, 4.81. Found:
C, 68.57; H, 6.38; N, 4.87.
syrup: [ꢀŠ +93ꢁ (c 1.2, CHCl3); IR (neat): ꢃ 2090
1
1
(N=C=S) cm ; H NMR (CDCl3): ꢂ 7.40±7.05
0
0
Methyl 2-azido-3,4,6-tri-O-benzyl-2-deoxy-a-d-
glucopyranosyl-(1!3)-2,4,6-tri-O-benzyl-a-d-gluco-
pyranoside (16).ÐA solution of 15 (168 mg,
0.193 mmol) in methanol (3 mL) was treated with
methanolic M sodium methoxide for 2 h at room
temp. After neutralization with Amberlite IR-120B
(H+) resin, the mixture was evaporated to dryness.
The residue was dissolved in DMF (3 mL), and it
was ®rst treated with sodium hydride (23 mg,
(m, 30 H, 6ÂPh), 5.53 (d, 1 H, J1 ,2 3.7 Hz, H-10),
4.89 and 4.86 (ABq, Jgem 12.7 Hz, PhCH2), 4.82
and 4.42 (ABq, Jgem 11.0 Hz, PhCH2), 4.75 and
4.52 (ABq, Jgem 11.4 Hz, PhCH2), 4.74 (d, 1 H, J1,2
3.7 Hz, H-1), 4.65 and 4.27 (ABq, Jgem 12.1 Hz,
PhCH2), 4.60±4.49 (m, 4 H, 2ÂPhCH2), 4.25±4.22
(m, 1 H, H-50), 4.16 (dd, 1 H, J2,3 9.9, J3,4 9.5 Hz,
H-3), 3.95 (dd, 1 H, J2 ,3 10.3, J3 ,4 9.2 Hz, H-30),
3.83 (dd, 1 H, J4,5 9.5 Hz, H-4), 3.75±3.67 (m, 3 H,
H-5,6,40), 3.62 (dd, 1 H, H-20), 3.54 (dd, 1 H, H-2),
3.42±3.32 (m, 2 H, H-60), 3.36 (s, 3 H, Me). Anal.
Calcd for C56H59NO10S: C, 71.70; H, 6.34; N, 1.49.
Found: C, 71.77; H, 6.39; N, 1.51.
0
0
0
0
ꢁ
0.58 mmol) for 0.5 h at 0 C, and then with benzyl
bromide (46 ꢄL, 0.385 mmol) for 20 h at 0 ꢁC.
After addition of a small amount of methanol, the
mixture was diluted with ethyl acetate (50 mL) and
washed with water, dried, and evaporated. The
residue was chromatographed on silica gel (15 g,
Methyl 3,4,6-tri-O-benzyl-2-deoxy-2-{N3-[(1R)-
(1,2,3,5/4)-2,3,4,5-tetrahydroxy-2-(hydroxymethyl)-
cyclopentyl]thioureido}-a-d-glucopyranoside (19).Ð
A mixture of the isothiocyanate 10 (141 mg,
1:6 ethyl acetate±hexane) to give 16 (115 mg, 65%)
21
as a syrup: Rf 0.81 (1:5 ethyl acetate±toluene); [ꢀŠ
d

S. Ogawa et al./Carbohydrate Research 370 (1998) 83±95
91
0.278 mmol) and 1l-(1,2,4,5/3)-5-amino-1-(hydroxy-
methyl)-1,2,3,4-cyclopentanetetrol [7] (18, 41.6 mg,
0.232 mmol) in 75% aq DMF was stirred for 21 h
at room temp, and then evaporated. The residue
was chromatographed on silica gel (7.5 g, 1:5 ethyl
acetate±hexane ! 1:4 ethanol±toluene) to give the
The mixture was acetylated with acetic anhy-
dride (1 mL) in pyridine (1 mL) for 4 h at room
temp. The products were chromatographed on a
silica gel column (5 g, 1:5 acetone±toluene) to give
the octa-N,O-acetyl derivatives 23 (38 mg, 53%)
and 24 (7 mg, 9%) as a syrup.
thiourea 19 (154 mg, 97%) as a syrup, Rf 0.39 (1:4
For compound 23: Rf 0.38 (1:4 acetone±toluene);
19
[ꢀŠ +11.4ꢁ (c 1.3, CHCl3); IR (neat): ꢃ 1750
22
d
ethanol±toluene) [ꢀŠ +50ꢁ (c 0.81, CHCl3); IR
d
(ester) and 1690 (amide, C=N) cm ; H NMR
1
1 1
(neat): ꢃ 3325 (OH and NH) and 1540 cm (NH).
Anal. Calcd for C35H44N2O10S: C, 61.39; H, 6.48;
N, 4.09. Found: C, 61.17; H, 6.58; N, 3.99.
(CDCl3): ꢂ 5.51 (dd, 1 H, J2,3 10.3, J3,4 9.9 Hz, H-
0
0
0
0
0
0
3), 5.46 (ddd, 1 H, J5 ,6 7.3, J6 ,7 7.3, J6 ,8 0.7 Hz,
H-60), 5.36 (dd, 1 H, J7 ,8 8.4 Hz, H-70), 5.29 (dd, 1
H, H-80), 5.09 (dd, 1 H, J4,5 9.5 Hz, H-4), 4.95 (d, 1
H, H-50), 4.75 (d, 1 H, J1,2 3.7 Hz, H-1), 4.36 (dd, 1
H, J5,6a 4.8, J6gem 12.1 Hz, H-6a), 4.17 (s, 2 H, H-
90), 4.08 (dd, 1 H, J5,6b 2.2 Hz, H-6b), 4.04 (ddd, 1
H, H-5), 3.92 (dd, 1 H, H-2), 3.37 (s, 3 H, Me),
2.49, 2.23, 2.12, 2.073, 2.070, 2.05, and 1.96 (7 s, 3,
3, 3, 3, 3, 3, 6, 3 H, 8ÂAc). Anal. Calcd for
C30H40N2O18: C, 50.28; H, 5.63; N, 3.91. Found:
C, 50.12; H, 6.01; N, 3.77.
0
0
(1S,5R,6S,7R,8S)-1- (20) and (1S,5R,6S,7S,8S)-
6-Hydroxymethyl-3-(methyl 3,4,6-tri-O-benzyl-2-
deoxy-a-d-glucopyranos-2-yl)amino-2-oxa-4-azabi-
cyclo[3.3.0]octane-6,7,8-triol (21).ÐTo a solution
of the thiourea 19 (129 mg, 0.188 mmol) in 1:6
acetone±diethyl ether (3 mL) was added four por-
tions of yellow mercury(II) oxide (120 mg,
0.56 mmol, totally 490 mg, 12 molar equiv) at
intervals of 3, 8, 19 h, and the mixture was stirred
for a total of 25 h. An insoluble material was
removed by ®ltration through a Celite bed, and the
®ltrate was evaporated to dryness. The residue was
chromatographed on silica gel (11 g, 1:4 ethanol±
toluene) to give a mixture (96 mg, 77%) of 20 and
21 as a hygroscopic syrup: Rf 0.15 and 0.23 (1:2:10
acetic acidÐethanol±toluene); IR (neat) ꢃ 3350
(OH and NH) and 1660 cm 1 (C=N). Anal. Calcd
For compound 24: Rf 0.29 (1:4 acetone±toluene),
[ꢀ2d4] +49ꢁ (c 0.4, CHCl3); IR (neat): ꢃ 1750 (ester)
1
and 1700 (amide, C=N) cm ; 1H NMR (CDCl3):
ꢂ 5.52±5.45 (m, 2 H, H-70,80), 5.49 (dd, 1 H, J2,3
0
0
10.3, J3,4 9.5 Hz, H-3), 5.20 (d, 1 H, J1 ,5 8.4 Hz, H-
50), 5.03 (dd, 1 H, J4,5 9.9 Hz, H-4), 4.93 (d, 1 H,
J1,2 3.3 Hz, H-1), 4.80 and 4.64 (ABq, Jgem 11.5 Hz,
H-90), 4.69 (br d, H-10), 4.31 (dd, 1 H, J5,6a 4.8,
J6gem 12.1 Hz, H-6a), 4.09 (dd, 1 H, J5,6b 2.4 Hz, H-
6b), 4.01 (ddd, 1 H, H-5), 3.84 (dd, 1 H, H-2), 3.38
(s, 3 H, Me), 2.41, 2.13, 2.11, 2.10, 2.08, 2.07, 2.02,
and 1.96 (8 s, each 3 H, 8 Ac). Anal. Found: C,
50.22; H, 5.87; N, 3.93.
.
for C35H42N2O10 0.5H2O: C, 63.72; H, 6.57; N,
4.25. Found: C, 63.34; H, 6.58: N, 4.23.
(1S,5R,6S,7R,8S)-6,7,8-tri-O-Acetyl-1- (23) and
(1S,5R,6S,7S,8R)-6,7,8-tri-O-acetyl-6-acetoxy-
methyl-3-(methyl 3,4,6-tri-O-acetyl-2-deoxy-a-d-
glucopyranos-2-yl)amino-2-oxa-4-azabicyclo[3.3.0]-
octane-6,7,8-triol (24).ÐTo liquid ammonia (5 mL)
containing sodium (340 mg, 15 mmol) was added a
solution of the mixture (96 mg, 0.15 mmol) of 20
and 21 in THF (2 mL) at 78 ꢁC, and it was stirred
for 15 h at the same temp. After addition of
ammonium chloride (1.2 g, 22 mmol), the mixture
was allowed to stand at room temperature, until all
ammonia was removed by spontaneous evapora-
tion. The residual product was dissolved in water
(5 mL), the solution was washed with chloroform
(3 mLÂ2), and the water layer was applied to a
column of Dowex-50WÂ2 (H+) resin and eluted
with 0.25 M aq ammonia to give a mixture (38 mg,
63%) of the cyclic isoureas 3 and 22 as a white
solid: Rf 0.12 (4:1 acetonitrile±water); IR (KBr): ꢃ
Methyl 2-deoxy-2-{(1S,5R,6S,7R,8S)-6,7,8-tri-
hydroxy-1-(hydroxymethyl)-2-oxa-4-azabicyclo-
[3.3.0]octan-3-ylideneamino}-a-d-glucopyranoside
(3).ÐCompound 23 (24 mg, 0.032 mmol) was trea-
ted with methanolic sodium methoxide (0.2 mL) in
ꢁ
methanol (1 mL) for 2.5 h at 15 C. The product
was chromatographed on Dowex-50WÂ2 (H+)
resin (2 mL, 0.5 M aq ammonia) to give 3 (11 mg,
85%) as a white powder, Rf 0.24 (1:2:10 acetic
acid±water±acetonitrile), [ꢀŠ20 +87.5ꢁ (c 0.56, water);
d
1
IR (neat): ꢃ 3450 (OH, NH) and 1690 (C=N) cm ;
1H NMR (D2O): ꢂ 4.79 (d, 1 H, J1,2 3.7 Hz, H-1), 4.01
(d, 1 H, J5 ,6 6.2 Hz, H-50), 3.74 (dd, 1 H, J5,6a 2.8,
J6gem 12.3 Hz, H-6a), 3.69±3.50 (m, 6 H, H-
5,60,70,80,90), 3.57 (dd, 1 H, J5,6b 5.1 Hz, H-6b), 3.54
(dd, 1 H, J2,3 9.9, J3,4 8.4 Hz, H-3), 3.49 (dd, 1 H,
H-2), 3.35 (dd, 1 H, J4,5 9.9 Hz, H-4), 3.27 (s, 3 H,
Me).
0
0
1
1
3440 (OH and NH) and 1653 (C=N) cm ; H
NMR (D2O): ꢂ 4.32 (d, 0.3 H, J1 ,5 9.2 Hz, H-50),
0
0
4.16 (d, 0.7 H, J5 ,6 7.3 Hz, H-50).
0
0

92
S. Ogawa et al./Carbohydrate Research 370 (1998) 83±95
Methyl 3,4,6-tri-O-benzyl-2-deoxy-2-{N3-[(1R)-
gel column chromatography (1.2 g, 1:5 acetone±
toluene) to give the peracetate 28 (5.0 mg, 16%) as
(1,2,3,5/4)-2,3,4,5-tetrahydroxy-2-(hydroxymethyl)-
cyclopentyl]thioureido}-a-d-glucopyranosyl-(1!3)-
2,4,6-tri-O-benzyl-a-d-glucopyranoside (25).ÐA
mixture of the isothiocyanate 17 (86.5 mg,
0.092 mmol) and the aminocyclitol 18 (17 mg,
0.095 mmol) in 3:3:2 DMF±THF±water (4 mL) was
stirred for 5 days at room temperature, and then
evaporated. The residue was chromatographed on
silica gel (7 g, 1:4 ethyl acetate±hexane ! 1:10
ethanol±toluene) to give the thiourea 25 (79 mg,
a syrup: Rf 0.63 (1:2 acetone-toluene), [ꢀŠ19 +56ꢁ (c
d
0.25, CHCl3), IR (neat) 1725 (OAc) and 1690
1
1
(C=N) cm , H NMR (CDCl3) ꢂ 5.45 (dd, 1 H,
J5 ,6 7.7, J6 ,7 8.1 Hz, H-600), 5.35 (dd, 1 H, J7 ,8
00 00
00 00
00 00
8.8 Hz, H-700), 5.34 (dd, 1 H, J2 ,3 9.9, J3 ,4 8.8 Hz,
0
0
0
0
H-30), 5.29 (d, 1 H, H-800), 5.07 (dd, 1 H, J4 ,5
0
0
10.3 Hz, H-40), 5.06 (dd, 1 H, J3,4 8.8, J4,5 10.3 Hz,
H-4), 4.99 (d, 1 H, J1,2 3.7 Hz, H-1), 4.95 (d, 1 H,
J1 ,2 3.7 Hz, H-10), 4.94 (d, 1 H, H-500), 4.79 (dd, 1
H, J2,3 9.9 Hz, H-2), 4.38±4.26 (m, 2 H, H-60), 4.31
(dd, 1 H, H-3), 4.23±4.11 (m, 1 H, H-50), 4.18 (dd,
1 H, J5,6 2.2, J6gem 12.5 Hz, H-6), 3.92 (dd, 1 H, H-
20), 3.84 (ddd, 1 H, H-5), 3.37 (s, 3 H, Me), 2.59,
2.23, 2.17, 2.15, 2.13, 2.07, 2.06, 2.05, 2.04, 2.03,
and 1.96 (11 s, each 3 H, 11ÂAc). Anal. Calcd for
C42H56N2O26: C, 50.20; H, 5.62; N, 2.79. Found:
C, 50.29; H, 5.82; N, 2.90.
0
0
76%) as a syrup: Rf 0.61 (1:4 ethanol±toluene);
22
[ꢀŠ +16ꢁ (c 1.1, CHCl3). Anal. Calcd for C62H72
d
N2O15S: C, 66.65; H, 6.50; N, 2.51. Found: C,
66.88; H, 6.54; N, 2.49.
Methyl 3,4,6-tri-O-benzyl-2-deoxy-2-[(1S,5R,6S,
7R,8S)-6,7,8-trihydroxy-1-(hydroxymethyl)- (26)
and Methyl 3,4,6-tri-O-benzyl-2-deoxy-2-[(1S,5R,
6S,7S,8S)-6,7,8-trihydroxy-6-(hydroxymethyl)-2-
oxa-4-azabicyclo[3.3.0]octan-3-ylideneamino]-a-d-
glucopyranosyl-(1!3)-2,4,6-tri-O-benzyl-a-d-gluco-
pyranoside (27).ÐThe thiourea 25 (34 mg,
0.0304 mmol) was dissolved in 1:6 acetone±diethyl
ether (1 mL), and seven portions of mercury(II)
oxide (20 mg, 3.0 equiv) were added in the interval
of 3 h for 30 h. An insoluble material was removed
by ®ltration through a Celite bed, and the ®ltrate
was evaporated to give a mixture (33 mg, ꢀ100%)
of 26 and 27, Rf 0.47 and 0.36 (1:2:10 acetic acid±
ethanol±toluene), IR (neat), ꢃ 3350 (OH and NH)
Methyl 2-deoxy-2-[(1S,5R,6S,7R,8S)-6,7,8-tri-
hydroxy-1-(hydroxymethyl)-2-oxa-4-azabicyclo-
[3.3.0]octan-3-ylideneamino]-a-d-glucopyranosyl-
(1!3)-a-d-glucopyranoside (4).ÐA solution of 28
(5.0 mg, 5.0 mmol) in methanol (1 mL) was treated
with ꢁM methanolic sodium methoxide (0.2 mL) at
15 C for 4 h. The solution was applied to a col-
umn of Dowex-50WÂ2 (H+) resin that was eluted
with 0.5 M aq ammonia to give 4 (2.5 mg, 93%) as
a white solid: Rf 0.16 (1:2:10 acetic acid±water±
22
d
acetonitrile), [ꢀŠ +203ꢁ (c 0.19, water); IR (KBr
1
1
and 1690 (C=N) cm . Anal. Calcd for C62H70
disk) ꢃ 3430 (NH and OH) and 1655 (C=N) cm ,
1H NMR (D2O): ꢂ 5.24 (d, 1 H, J1 ,2 3.3 Hz, H-10),
.
N2O15 1.5H2O: C, 67.07; H, 6.63; N, 2.52. Found:
C, 66.80: H, 6.43; N, 2.60.
Methyl 3,4,6-tri-O-acetyl-2-deoxy-2-[N-acetyl-
(1S,5R,6S,7R,8S)-6,7,8-triacetoxy-1-(acetoxymethyl)-
2-oxa-4-azabicyclo[3.3.0]octan-3-ylideneamino]-a-d-
glucopyranosyl-(1!3)-2,4,6-tri-O-acetyl-a-d-gluco-
pyranoside (28).ÐTo liquid ammonia (5 mL) con-
0
0
00 00
4.67±4.62 (m, 1 H, H-1), 4.05 (d, 1 H, J5 ,6 6.2 Hz,
H-500), 3.89±3.48 (m, 15 H, H-2,3,4,5,6,20,30,60,
600,700,800,900), 3.41 (dd, 1 H, J3 ,4 9.2, J4 ,5 9.9 Hz, H-
40), 3.28 (s, 3 H, Me).
0
0
0
0
Methyl 4,6-di-O-benzyl-3-deoxy-3-[2,3:4,6-di-O-
isopropylidene-5a-carba-a-d-xylo-5(5a)-enopyrano-
sylamino]-a-d-altropyranoside (33) and methyl 4,6-
di-O-benzyl-2-deoxy-2-[2,3:4,6-di-O-isopropylidene-
5a-carba-a-d-xylo-hex-5(5a)-enopyranosylamino]-
a-d-glucopyranoside (36).ÐA mixture of 2,3:4,6-di-
O-isopropylidene-5a-carba-ꢀ-d-xylo-hex-5(5a)-en-
opyranosylamine4 [23] (29, 74 mg, 0.29 mmol) and
methyl 2,3-anhydro-4,6-di-O-benzyl-ꢀ-d-glucopyr-
anoside (32, 85 mg, 0.24 mmol) in 2-propanol
(0.50ꢁmL) was heated in a sealed tube for 5 days at
120 C, and then evaporated. The residual pro-
ducts were chromatographed on a silica gel column
.
taining sodium (70 mg, 3.05 mg atom, 100 equiv)
was added a solution of a mixture (33 mg,
0.03 mmol) of the hexabenzyl ethers 26 and 27 in
THF (2 mL) at 78 ꢁC, and the mixture was stirred
for 15 min at the same temperature. After addition
of ammonium chloride (244 mg, 4.6 mmol), the
mixture was allowed to reach room temp, the
ammonia being removed by spontaneous evapora-
tion. The residual product was diluted with water
(5 mL), the solution was washed with chloroform
(3 mLÂ2), and the water layer was evaporated to
dryness. The residue was acetylated with acetic
anhydride (0.5 mL) in pyridine (1 mL) overnight at
room temp, and the product was puri®ed by silica
4
Compound 29 was provided by hydrogenolysis of the
corresponding azido compound with Raney nickel catalyst
and used directly without puri®cation.

S. Ogawa et al./Carbohydrate Research 370 (1998) 83±95
93
(14 g, 1:3 ethyl acetate±toluene) to give ®rst the
gluco isomer 36 (8.1 mg, 5.6%) as a slightly yellow
syrup, and then the altro isomer 33 (96 mg, 66%)
as a colorless syrup.
A 23 mg-portion of the major product 33 was
acetylated with acetic anhydride in pyridine to give
the 2-acetate 34 (21 mg, 87%) as a syrup.
For compound 34: Rf 0.52 (1:3 ethyl acetate±
and 4.13 (ABq, Jgem 14.5 Hz, H-60), 3.95 (d, 1 H,
J3 ,4 7.0 Hz, H-40), 3.70±3.45 (m, 7 H, H-1,4,5,6,
10,20,30), 3.38 (s, 3 H, Me), 2.60 (dd, 1 H, J2,3 9.5 Hz,
H-2). Anal. Calcd for C28H37NO9: C, 63.26: H,
7.02; N, 2.63. Found: C, 62.99; H, 7.12; N, 2.64.
Methyl 4,6-di-O-benzyl-2,3-dideoxy-2,3-[2,3:4,6-
di-O-isopropylidene-5a-carba-a-d-xylo-hex-5(5a)-
enopyranosylepimino]-a-d-allopyranoside (39).ÐTo
a stirred solution of 33 (125 mg, 0.204 mmol) in
pyridine (3 mL) at 0 ꢁC was added methanesulfonyl
chloride (20ꢁ.5 ꢄL, 0.26 mmol). Stirring was con-
tinued at 0 C while three additional portions of
the acid chloride (in all 51 ꢄL, 0.65 mmol) were
added at intervals of 4 h. After addition of metha-
nol (0.2 mL), the mixture was diluted with ethyl
acetate (60 mL), washed with water, dried, and
evaporated. The residual crude mesylate 35 was
dissolved in toluene (3 mL), and the solution was
treated with DBU (46 ꢄL, 0.31 mmol, 1.5 equiv)
for 36 h at 60 ꢁC. Then the mixture was evaporated
and the residue was chromatographed on silica gel
(8 g, 1:9 ethyl acetate±toluene) to give 39 (16 mg,
95%) as a syrup: Rf 0.46 (1:3 butanone±toluene),
0
0
23
d
ꢁ
1
toluene), [ꢀŠ +122 (c 1.1, CHCl3), H NMR
(CDCl3): ꢂ 7.82±7.37 (m, 10 H, 2ÂPh), 5.49 (br d, 1
H, J1 ,5a 4.8 Hz, H-5a0), 5.20 (dd, 1 H, J1,2 1.5, J2,3
3.7 Hz, H-2), 4.68 and 4.56 (ABq, Jgem 12.5 Hz,
PhCH2), 4.65 (br s, 1 H, H-1), 4.58 and 4.43 (ABq,
0
0
0
0
Jgem 12.5 Hz, PhCH2), 4.47 (br d, 1 H, J3 ,4 8.1 Hz,
0
H-40), 4.41 and 4.12 (ABq, J6 gem 13.9 Hz, H-60),
0
0
4.05±4.00 (m, 1 H, H-5), 4.02 (dd, 1 H, J2 ,3 9.9 Hz,
H-30), 3.82±3.75 (m, 3 H, H-4,6), 3.69 (dd, 1 H,
J1 ,2 4.4 Hz, H-10), 3.53 (dd, 1 H, H-6), 3.31 (br t, 1
H, J3,4 3.7 Hz, H-3), 2.08 (s, 3 H, Ac), 1.55, 1.49,
1.46, and 1.42 (4 s, each 3 H, 2ÂCMe2). Anal.
Calcd for C36H46NO10: C, 66.24; H, 7.10; N, 2.14.
Found: C, 66.10; H, 7.25; N, 2.45.
0
0
For compound 36: Rf 0.61 (1:3 butanone±
21
d
27
d
toluene), [ꢀŠ +9.2ꢁ (c 1.2, CHCl3), H NMR
[ꢀŠ +201ꢁ (c 1.0, CHCl3); H NMR (CDCl3): ꢂ
1
1
0
0
(CDCl3): ꢂ 7.34±7.23 (m, 10 H, 2ÂPh), 5.55 (d, 1
7.38±7.21 (m, 10 H, 2ÂPh), 5.30 (d, 1 H, J1 ,5a
H, J1 ,5a 4.8 Hz, H-5a0), 4.93 and 4.54 (ABq, Jgem
11.5 Hz, PhCH2), 4.85 (d, 1 H, J1,2 3.3 Hz, H-1),
4.63 and 4.50 (ABq, Jgem 12.5 Hz, PhCH2), 4.49 (d,
4.4 Hz, H-5a0), 4.90 (d, 1 H, J1,2 4.8 Hz, H-1), 4.69
and 4.54 (ABq, Jgem 11.4 Hz, PhCH2), 4.63 and
4.47 (ABq, Jgem 12.1 Hz, PhCH2), 4.47 (dd, 1 H,
0
0
1 H, J3 ,4 8.1 Hz, H-40), 4.46 and 4.17 (ABq, 1 H,
J6 gem 13.9 Hz, H-60), 4.01 (dd, 1 H, J2 ,3 9.9 Hz, H-
J3 ,4 8.1, J2 ,4 3.3 Hz, H-40), 4.45 (dd, 1 H, J2 ,3
0
0
0
0
0
0
0
0
7.1 Hz, H-30), 4.33 and 4.04 (ABq, Jgem 14.1 Hz, H-
60), 3.87±3.83 (m, 2 H, H-4,5), 3.69 (dd, 1 H, J5,6a
3.0, J6gem 10.4 Hz, H-6a), 3.62 (dd, 1 H, J5,6b 1.5 Hz,
0
0
0
30), 3.79 (dd, 1 H, J1 ,2 5.1 Hz, H-10), 3.76 (dd, 1 H,
J5,6a 6.9, J6gem 9.5 Hz, H-6a), 3.75 (dd, 1 H, J2,3
9.9, J3,4 8.8 Hz, H-3), 3.73 (dd, 1 H, J4,5 8.1 Hz, H-
4), 3.57 (dd, 1 H, J5,6b 1.5 Hz, H-6b), 3.56 (m, 1 H,
H-5), 3.37 (s, 3 H, Me), 2.73 (dd, 1 H, H-2), 1.55,
1.48, 1.47, and 1.42 (4 s, each 3 H, 2ÂCMe2). Anal.
Calcd for C34H45NO9: C, 66.75; H, 7.41; N, 2.29.
Found: C, 66.64; H, 7.47; N, 2.04.
0
0
H-6b), 3.55 (ddd, 1 H, J1 ,2 3.7 Hz, H-20), 3.32 (s, 3
0
0
H, Me), 2.48 (dd, 1 H, J1 ,2 3.7, J1 ,5a 4.4 Hz, H-10),
2.38 (dd, 1 H, J2,3 6.8 Hz, H-2), 2.07 (dd, 1 H, J3,4
1.8 Hz, H-3), 1.54, 1.52, 1.44, and 1.43 (4 s, each 3
H, 2ÂCMe2). Anal. Calcd for C34H43NO8: C, 68.78;
H, 7.30; N, 2.36. Found: C, 68.65; H, 7.29; N, 2.58.
Reaction of the aziridine 39 with sodium acetate
in aq acetic acid.ÐA mixture of 39 (62 mg,
0.105 mmol) and sodium acetate (215 mg,
2.62 mmol) in 80% aq acetic acid (5 mL) was stir-
0
0
0
0
Methyl 4,6-di-O-benzyl-2-deoxy-2-[5a-carba-a-
d-xylo-hex-5(5a)-enopyranosylamino]-a-d-gluco-
pyranoside (37).ÐA solution of 36 (24 mg,
0.040 mmol) in aqꢁ80% acetic acid (2 mL) was stir-
red for 3 h at 60 C, and then evaporated. Chro-
matography of the residual product on silica gel
(2 g, 1:7 methanol±chloroform) gave 37 (20 mg,
ꢁ
red for 3 days at 90 C, and then evaporated. The
residue was treated with acetic anhydride (1 mL)
and pyridine (3 mL) overnight at room temp, and
the products were chromatographed on silica gel
(4 g, 1:9 acetone±toluene) to give a ca. 4:5 mixture
(58 mg, 74%) of methyl 2-O-acetyl-4,6-di-O-ben-
zyl-3-deoxy-3-[2,3,4,6-tetra-O-acetyl-5a-carba-ꢀ-d-
xylo-hex-5(5a)-enopyranosylamino]-ꢀ-d-altropyr-
anoside (40) and methyl 3-O-acetyl-4,6-di-O-ben-
zyl-2-deoxy-2-[2,3,4,6-tetra-O-acetyl-5a-carba-ꢀ-d-
96%) as a syrup: Rf 0.34 (1:3 ethanol±toluene),
21
d
(OH and NH) and 1650 (NH) cm ; H NMR
[ꢀŠ +178ꢁ (c 0.6, methanol); IR (KBr): ꢃ 3450
1
1
(CD3OD): ꢂ 7.36±7.19 (m, 10 H, 2ÂPh), 5.93 (br d,
1 H, J1 ,5a 2.9 Hz, H-5a0), 4.87 and 4.54 (ABq, Jgem
11.0 Hz, PhCH2), 4.77 (d, 1 H, J1,2 3.3 Hz, H-1),
4.55 and 4.47 (ABq, Jgem 12.1 Hz, PhCH2), 4.20
0
0

94
S. Ogawa et al./Carbohydrate Research 370 (1998) 83±95
0
0
xylo-hex-5(5a)-enopyranosylamino]-ꢀ-d-glucopyr-
anoside (41) that was dicult to separate: Rf 0.46
(1:5 acetone±toluene). Anal. Calcd for C38H47
NO14: C, 61.53; H, 6.39; N, 1.89. Found: C, 61.27;
H, 6.32; N, 1.90.
The mixture (57 mg) of 40 and 41 was treated
with methanolic M sodium methoxide (0.2 mL) in
methanol (2 mL) for 1 h at room temp. The solu-
tion was applied to a column of Dowex-50WÂ2
(H+) resin (5 mL) and eluted with a mixture of 1:5
28% aq ammonia±methanol, and the products
were further separated by a preparative TLC (silica
gel, 1:5 ethanol±toluene, acidi®ed by a drop of
acetic acid; three irrigations) to give 37 (13 mg,
32%), identical in all respects to the compound
previously obtained.
1 H, J1 ,2 4.0 Hz, H-20), 4.97 (dd, 1 H, J4,5 9.9 Hz,
H-4), 4.81 (d, 1 H, J1,2 3.3 Hz, H-1), 4.66 and 4.36
(ABq, J6 gem 12.8 Hz, H-60), 4.27 (dd, 1 H, J5,6a 4.8,
0
J6gem 12.1 Hz, H-6a), 4.07 (dd, 1 H, J5,6b 2.2 Hz, H-
6b), 3.92 (ddd, 1 H, J4,5 9.9 Hz, H-5), 3.69 (br dd,
H-10), 3.42 (s, 3 H, Me), 2.83 (dd, 1 H, H-2), 2.17,
2.09, 2.07, 2.06, 2.04, and 2.02 (6 s, 6, 3, 3, 3, 3, and
3 H, 7ÂAc). Anal. Calcd for C28H39NO16: C, 52.09;
H, 6.09; N, 2.17. Found: C, 51.96; H, 6.32; N, 2.40.
Biological assay.ÐYeast ꢀ-glucosidase activity
was assayed according to the reported method of
Tsuji et al. [30], and rat intestine sucrase±iso-
maltase activity was determined under the same
conditions. Processing glucosidase I activity was
assayed as reported previously [30] with the follow-
ing two modi®cations: (1) Triton X-100-solubi-
lized, [14C]-glucose-labeled vesicular stomatitis
virus glycoprotein was used instead of oligo-
saccharides liberated by protease treatment as the
substrate for the enzyme assay, and (2) 10% tri-
chloroacetic acid-insoluble, nonliberated [14C]-glu-
cose radioactivity was determined.
Methyl 2-deoxy-2-[5a-carba-a-d-xylo-hex-5(5a)-
enopyranosylamino]-a-d-glucopyranoside (5).ÐA
solution of 37 (20 mg, 0.037 mmol) in THF (1 mL)
was added to liquid ammonia (5 mL) containing
ꢁ
sodium (86 mg, 3.7 mmol) at 75 C, and the mix-
ture was stirred for 15 h at the same temperature.
The reaction mixture was processed in the conven-
tional manner, and the product was puri®ed on a
column of Dowex-50WÂ2 (H+) resin (20 mL)
with aq 0.5 M ammonia as eluant to give 5 (10 mg,
Acknowledgements
78%) as a hygroscopic powder: Rf 0.39 (1:3 water±
We sincerely thank Mr. Koichi Hokazono for
performing elementary analyses and Dr. Akira
Takatsuki (RIKEN, Wako, Saitama, Japan) for
carrying out the bioassays.
21
d
acetonitrile), [ꢀŠ +206ꢁ (c 0.5, water), IR (KBr
1
1
disk): ꢃ 3480 (OH and NH), 1610 (NH) cm ; H
NMR (D2O): ꢂ 5.83 (d, 1 H, J1 ,5a 4.8 Hz, H-5a0),
4.72 (d, 1 H, J1,2 3.7 Hz, H-1), 4.10 and 3.98 (ABq,
0
0
J6 gem 13.9 Hz, H-60), 3.92 (d, 1 H, J3 ,4 5.9 Hz, H-
40), 3.74 (dd, 1 H, J5,6a 2.0, J6gem 12.3 Hz, H-6a),
3.62 (dd, 1 H, J5,6b 5.3 Hz, H-6b), 3.52 (dd, 1 H,
0
0
0
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0
0
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d
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