Synthesis of β-D-ribofuranosyl-(1→3)-α-L-rhamnopyranose by in situ activating glycosylation using 1-OH sugar derivative and Me3SiBr-CoBr2-Bu4NBr-molecular sieves 4A system

Article abstract of DOI:10.1246/bcsj.74.1679

Β-D-Ribofuranosyl-(1→3)-α-L-rhamnopyranosyl-(1→3)- L-rhamnopyranose, the trisaccharide repeating unit of the C. freundii O28, 1c O-specific polysaccharide, was synthesized using in situ activating glycosylation of the 1-OH sugar derivatives and a reagent mixture of trimethylsilyl bromide, cobalt(II) bromide, tetrabutylammonium bromide, and molecular sieves 4A. Regioselective tritylation was useful for synthesizing the 3-OH derivatives of methyl, allyl, and benzyl α-L-rhamnosides.

Full text of DOI:10.1246/bcsj.74.1679

c. Jpn.
© 2001 The Chemical Society of Japan
Bull. Chem. Soc. Jpn., 74, 1679–1694 (2001) 1679
e Chemical
ciety of Ja-
n
e Chemical
ciety of Ja-
n
Synthesis of β-D-Ribofuranosyl-(1→3)-α-L-rhamnopyranosyl-(1→3)-L-
rhamnopyranose by in situ Activating Glycosylation Using 1-OH Sugar
Derivative and Me3SiBr–CoBr2–Bu4NBr–Molecular Sieves 4A System
Synthesis of β-D-Ribf-(1→3)-α-L-Rhap-(1→3)-
M. Hirooka et al.
01
79
Motoko Hirooka,* Yoko Mori, Akiko Sasaki, Shinkiti Koto,* Yoshika Shinoda, and Aya Morinaga
94
School of Pharmaceutical Sciences, Kitasato University, Shirokane, Minato-ku, Tokyo 108-8641
(Received February 14, 2001)
SJA8
09-2673
054
β-D-Ribofuranosyl-(1→3)-α-L-rhamnopyranosyl-(1→3)-L-rhamnopyranose, the trisaccharide repeating unit of the
C. freundii O28,1c O-specific polysaccharide, was synthesized using in situ activating glycosylation of the 1-OH sugar
derivatives and a reagent mixture of trimethylsilyl bromide, cobalt(Ⅱ) bromide, tetrabutylammonium bromide, and mo-
lecular sieves 4A. Regioselective tritylation was useful for synthesizing the 3-OH derivatives of methyl, allyl, and benzyl
α-L-rhamnosides.
01
01
.5
0
The development of new methods for glycosylation has al-
ways been important in synthetic carbohydrate chemistry.1
Several modern glycosylation reactions giving high yield with
high stereoselectivity have been established.2 In addition, re-
cent efforts to simplify the glycosylation procedure have devel-
oped various kinds of in situ activating glycosylations using a
1-OH sugar derivative and a reagent mixture.3 However, such
methods have not been well applied for oligosaccharide syn-
thesis.4 We wish to report on new results of the application of
a reagent system5 (TCTM system) consisting of trimethylsilyl
bromide (Me3SiBr), cobalt(Ⅱ) bromide, tetrabutylammonium
bromide (TBAB), and molecular sieves 4A (MS4A) to oli-
gosaccharide synthesis.
sylations. On the other hand, the L-rhamnosyl donor 2 produc-
es its α- or β-glycoside as a main condensate, depending on
the acceptor used (Runs 9–16). The reaction with 4 (Runs 15
and 16) showed almost complete α-selectivities. 1,2-Dichlo-
roethane instead of dichloro-methane5 as the solvent raised
yields of glycosides (Runs 6, 8, 14, and 16). A self-condensa-
tion product 14 was formed4a in the case of a less-reactive ac-
ceptor 4 in dichloromethane (Run 15).
The results mentioned above prompted us to synthesize β-D-
ribofuranosyl-(1→3)-α-L-rhamnopyranosyl-(1→3)-L-rhamno-
pyranose (15)12 (Fig. 2) and the related oligosaccharides to
show the utility of the TCTM system. The trisaccharide 15 is a
trisaccharide repeating unit of the C. freundii O28,1c O-specif-
ic polysaccharide. To our knowledge, 15 has not been synthe-
sized.
The TCTM system5 is an in situ activating reagent system6
for a 1-OH sugar derivative, such as 2,3,4,6-tetra-O-benzyl-D-
glucopyranose (DOH), as a donor in the presence of an accep-
tor (AOH) to give an anomeric mixture of the corresponding
glycosides DOA (Eq. 1).
First, we tried to synthesize various protected disaccharides
(16b, 17b, 18b, 19, and 20a) to check the feasibility of this
plan (Fig. 3). All of these disaccharides are structurally related
to the above-described polysaccharide. For this purpose, do-
nors 21 and 22 as well as acceptors 23, 24, 25, and 26 were
conveniently prepared as described below.
DOH + AOH → DOA + H2O
(1)
This reaction can be conducted at room temperature. This is a
convenient reaction, because an acceptor can be added into the
reaction system before adding of the activating reagent(s) for
the donor (one-pot-one-stage method).6b We have now applied
the TCTM system to 2,3,5-tri-O-benzyl-D-ribofuranose (1)7
and 2,3,4-tri-O-benzyl-L-rhamnopyranose (2)8,9 (Fig. 1) in
their condensation with model acceptors, such as cyclohexyl-
methanol (CmOH), cyclohexanol (ChOH), methyl 2,3,4-tri-O-
benzyl-β-D-glucopyranoside (3),10 and methyl 2,3,6-tri-O-ben-
zyl-β-D-glucopyanoside (4).11 The results summarized in Ta-
ble 1 show that the ribosyl donor 1 gives the corresponding
glycosides with β-selectivity (Runs 1–8). In the case of Run 5
using acceptor 3 in dichloromethane as a solvent, a small
amount of methyl riboside 9 was formed. There have been re-
ported in situ activating β-D-ribofuranosylations using the lac-
tol 1.3x The present case is a new example of β-D-ribofurano-
The ribofuranose derivatives, 21 and 23, were prepared from
known monobenyl ether 27.13 It was found that a tin-mediated
monobenzylation of 27 afforded the desired 2-OH derivative
23 in 54% yield. The reaction was not regioselective to give
by-product 28 in 45% yield. However, tin- mediation was es-
sential to avoid the dibenzylation of 27. Allylation of 23 af-
forded 29, which was hydrolyzed into 21; the yield from 27
was 42%.
Some years ago, we synthesized the donor 229 via the regi-
oselective tritylation14 of 2-methoxyethyl α-L-rhamnopyrano-
side, and showed the utility of the trityl group at the secondary
OH group. For an extension of the utility of such tritylation,14
an analogous tritylation15 of 3016 was performed. The desired
3-O-trityl ether 31 was obtained mainly in 76% yield; the by-
product was 2-O-substituted 32. Compound 31 was benzylat-
ed and then hydrolyzed to afford the 3-OH derivative 24. Ally-

1680 Bull. Chem. Soc. Jpn., 74, No. 9 (2001)
Synthesis of β-D-Ribf-(1→3)-α-L-Rhap-(1→3)-
Fig. 1. Syntheses of D-ribofuranosides and L-rhamnopyranosides.
Table 1. Results of Glycosylation Using the TCTM Systema),b)
Run
Donor
Acceptor
Glycosides
Solvent
Yield/% (α/β)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
1
1
1
1
1
1
1
1
2
2
2
2
2
2
2
2
CmOH
CmOH
ChOH
ChOH
5a + 5b
5a + 5b
6a + 6b
6a + 6b
7a + 7b
7a + 7b
8a + 8b
8a + 8b
10a + 10b
10a + 10b
11a + 11b
11a + 11b
12a + 12b
12a + 12b
13
M
E
M
E
M
E
M
E
M
E
M
E
M
E
M
E
91 (10/90)
80 (16/84)
70 (15/85)
68 (25/75)
61 (21/79)c)
77 (31/69)
54 (49/51)
75 (45/55)
96 (20/80)
88 (36/64)
96 (71/29)
94 (75/25)
59 (39/61)
81 (42/58)
65d)
3
3
4
4
CmOH
CmOH
ChOH
ChOH
3
3
4
4
13
79
a) For acceptor (0.060 mmol), donor (1.3 eq), TMSBr (1.3 eq), CoBr2 (1.3 eq), Bu4NBr (1.3 eq),
MS4A (2.0 mg/mg of donor), and solvent (0.30 mL) were used. The reactions were conducted under
anhydrous conditions at 25 °C. b) ChOH = cyclohexanol, CmOH = cyclohexylmethanol, E = 1,2-
dichloroethane, M = dichloromethane. c) 9 was isolated (8% yield). d) 14 was isolated (> 20%
yield).
lation of 24 furnished 33, which was hydrolyzed into the 1-OH
into the 3-OH derivatives, 25 and 26, respectively. In prepar-
ing rhamnosides 30, 36, and 38, methanesulfonic acid as cata-
lyst was a good substitute for pungent hydrogen chloride.
For the disaccharide synthesis, β-D-ribofuranosylation reac-
tions were first carried out. Condensation between 1 and 24 in
the presence of the TCTM system stereoselectively gave the
desired 16b in ca. 40% yield (Table 2, Runs 1 and 2). A simi-
lar glycosylation of 25 with 1 afforded 17b as the main con-
derivative 22 in 30% yield from 30. It was found that a tin-me-
diated alkylation17 of 30 selectively formed the 3-O-allyl deriv-
ative 34, the precursor of 33. The yield of 22 from 30 by this
short route was 22% yield. A regioselecitve tritylation was
also applied to the other rhamnosides, 36 and 38, to yield the
3-O-trityl compound 37 (82%) and 40 (74%), respectively.
Similar to the case of 24, 37 and 40 were readily transformed

M. Hirooka et al.
Bull. Chem. Soc. Jpn., 74, No. 9 (2001) 1681
Fig. 2. The C. freundii O28, 1c O-specific polysaccharide and the related oligosaccharide fragments.
Table 2. Results of Oligosaccharide Synthesis Using the TCTM System
Run
DOH
mg
AOH
mg
Solventa)
DOA
%(α/β)
1
2
3
4
5
6
7
8
9
1
1
1
39.4
38.7
43.5
41.2
90.4
33.1
223.1
66.5
25.1
34.0
36.5
41.8
24
24
25
25
24
24
24
23
41
24
26
25
33.6
33.0
39.8
37.7
89.8
31.7
208.0
52.7
40.8
16.4
21.2
21.5
M
E
M
E
M
E
E
M
E
E
E
E
16a + 16b
16a + 16b
17a + 17b
17a + 17b
18a + 18b
18a + 18b
19
20a + 20b
42
42
53 (21/79)
56 (23/77)
46 (30/70)
59 (32/68)
77 (48/52)
57 (46/54)
50
59 (73/27)
45
40
1
21
21
22
2
1
10
11
12
43
43
43
45
46
42
52
a) E = 1,2-dichloroethane, M = dichloromethane.
densate (Run 3). The use of 1,2-dichloroethane slightly in-
creased the yields of the glycosides (Run 4). Glycosylation of
24 with 21 having an allyl group instead of a benzyl group at
the C-2 position yielded 18b with poor stereoselectivity (Runs
5 and 6). An α-L-Rhamnopyranosylation reaction of 24 was
also performed using 22 and the TCTM system to afford the
desired 19 in 50% yield with complete selectivity (Run 7).
However, a similar reaction using 2 and 23 did not produce the

1682 Bull. Chem. Soc. Jpn., 74, No. 9 (2001)
Synthesis of β-D-Ribf-(1→3)-α-L-Rhap-(1→3)-
Fig. 3. The synthetic routes to the monosaccharide building units: a. BnBr, Bu4NBr, Bu2SnO, MS4A/C6H6, ∆; b. AllBr, NaH/∆; c. aq
AcOH (80%), H2SO4/∆; d. TrCl, C5H5N/∆; e. BnBr, NaH/DMF, 0 °C → room temperature (rt); f. MeOH, CF3CO2H/CHCl3, rt; g.
Bu2SnO/MeOH, ∆; h. AllBr/DMF; i. AllOH, MeSO3H/∆; j. BnOH, MeSO3H/∆; k. (i) AcBr/AcOH, 0 °C, (ii) BnOH, Hg(CN)2/
MeNO2, rt, (iii) dil NaOMe, rt.
glycosides stereoselectively (Run 8).
condensation of 25 and 43 furnished 46 (Ran 12). Deallylation
of 46 yielded the trisaccharide donor 47. Catalytic debenzyla-
To build-up the trisaccharides, deallylation using palladi-
um(Ⅱ) chloride18 effectively converted 19 into the disaccharide
acceptor 41 in 81% yields (Fig. 4). Condensation of 41 with 1
proceeded with complete β-selectivity to give 42 in 45% yield
(Run 9). This was also obtained by way of a stereoselective
condensation of the resulting disaccharide donor 43, the deal-
lylated product of 17b, with 24 (Run 10). Catalytic debenzyla-
tion of 42 afforded the methyl glycoside 44. The structure of
the synthesized 44 was assigned by the determination of its 1H
and 13C NMR spectra in D2O. The signal at δ 111.2 indicates
the β-ribofuranosyl structure.19a The JC1,H1 values, 169.6 Hz
and 170.9 Hz, show the α-pyranosyl frameworks.19b The
1
tion of 47 afforded the above-described 15. The H and 13C
NMR spectra determined in D2O of the synthesized trisaccha-
ride 15 were consistent with its structure. The β-furanosyl
structure was assigned by the signal at δ 110.5.19a The JC1,H1
Ⅱ
value, 170.1 Hz, of C1 indicates an α-rhamnopyranosyl link-
age.19b NOE experiments as well as GHMQC experiments
gave results consistent with the structure of 15.
Two methyl glycosides of the disaccharide, which are struc-
turally related to 15, were synthesized. Debenzylation of 20a
gave the methyl glycoside 48. A similar debenzylation of 16b
afforded the other disaccharide 49. Deallylation of 18b and
subsequent debenzylation also afforded 49. The structures of
the methyl glycosides, 47 and 49, were confirmed by determin-
ing their 1H and 13C NMR spectra in D2O.
In summary, the TCTM system was useful for β-D-ribofura-
nosylation and α-L-rhamnopyranosylation. The utility of the
TCTM system was shown in the first synthesis of the trisac-
charide 15 as well as its methyl glycoside 44. Through this
work, the convenience of regioselective 3-O-tritylation9,14 of
α-L-rhamnopyranosides 30, 36, and 38, as well as of tin-medi-
Ⅱ
Ⅰ
NOE’s were observed between H1 and H3 as well as between
Ⅲ
Ⅱ
Ⅱ
Ⅰ
H1 and H3 . This indicates linkage 1 to the 3 linkage and
Ⅲ
Ⅱ
linkage 1 to the 3 linkage. These linkages were also as-
signed by GHMQC experiments; three-bond cross peaks were
Ⅱ
Ⅰ
Ⅲ
Ⅱ
seen between H1 and C3 as well as between H1 and C3 .
The condensation of 26 with the disaccharide donor 43 in the
presence of the TCTM system proceeded well to give the de-
sired trisaccharide derivative 45 in 42% yield (Run 11). De-
benzylation of 45 gave the desired free trisaccharide 15. The

M. Hirooka et al.
Bull. Chem. Soc. Jpn., 74, No. 9 (2001) 1683
Fig. 4. Synthesis of β-D-Ribf-(1→3)-α-L-Rhap-(1→3)-L-Rhap and the related glycosides (TCTM = Me3SiBr + CoBr2 + Bu4NBr
+ MS4A): a. PdCl2, NaOAc/aq AcOH (95%), rt; b. 1, TCTM/(CH2Cl)2, rt; c. 24, TCTM/(CH2Cl2), rt; d. H2, Pd–C (10%)/MeOH,
rt; e. 26, TCTM/(CH2Cl)2, rt; f. 25, TCTM/(CH2Cl2)2, rt.

1684 Bull. Chem. Soc. Jpn., 74, No. 9 (2001)
ated alkylations of 27 and 30 were shown.
Experimental20
Synthesis of β-D-Ribf-(1→3)-α-L-Rhap-(1→3)-
H2), 4.02 (dd, J2,3 = 4.5 Hz, J3,4 = 7 Hz, H3), 4.35 (ddd, J3,4 = 7
Hz, J4,5a = 6.0 Hz, J4,5b = 4 Hz, H4), 5.00 (d, J1,2 = 1 Hz, H1);
13C NMR (CDCl3, 75 MHz) δ 71.7 (C5), 79.0 (C3), 80.0 (C2),
80.4 (C4), 105.6 (C1, JC1,H1 = 171.0 Hz); 25.8 (2C), 26.6, 30.0
(2C), 37.8, 73.6 (cyclohexylmethyl).
The solvent systems for column chromatography on silica gel
(Kanto Chemical, No. 37047; gradient elusion) and thin-layer
chromatography (TLC) (Merck, DC-Plastikfolien Kieselgel 60
Found: C, 76.65; H, 8.02%. Calcd for C33H40O5: C, 76.71; H,
7.80%.
F
254, Art. 5735) were chloroform–MeOH (CM), 1,2–dichoroet-
Cylohexyl 2,3,5-Tri-O-benzyl-α- and β-D-ribofuranosides
(6a and 6b). 6a (the slower-moving (TK 20:1)): [α]D +62° (c
0.4, CHCl3); 1H NMR (CDCl3, 300 MHz) δ 3.38 (dd, J4,5a = 4 Hz,
J5a,5b = 10.5 Hz, H5a), 3.47 (dd, J4,5b = 3.5 Hz, J5a,5b = 10.5 Hz,
hane–AcOEt (DE), AcOEt–MeOH (EM), hexane–AcOEt (HE),
and PhMe–2-butanone (TK). Hydrogenolytic debenzylation was
carried out using a Parr-3911 hydrogenation apparatus under 340
kPa of H2 at room temperature. Evaporation was carried out under
reduced pressure. The optical rotations were measured on a JAS-
CO DIP-180 Digital Polarimeter at room temperature (20–25 °C),
unless otherwise specified. The 1H and 13C NMR spectra were re-
corded with a Varian VXR300 spectrometer or a Varian XL-400
spectrometer, along with measurements of the H,H-COSY, C,H-
COSY, and DEPT spectra. For assigning of the anomeric configu-
ration of the rhamnosides, their JC1,H1 values19b were determined
by gated decoupling with the NOE experiment. The assignments
of the spectra of 15 and 44 were made by auxiliary measurements
of HOHAHA, NOE difference, and HMQC spectra.
H5b), 3.77 (dd, J1,2 = 4 Hz, J2,3 = 6.5 Hz, H2), 3.85 (dd, J2,3
=
6.5 Hz, J3,4 = 4 Hz, H3), 4.24 (dt, J3,4 = J4,5a = 4 Hz, J4,5b = 3.5
Hz, H4), 5.18 (d, J1,2 = 4 Hz, H1); 13C NMR (CDCl3, 75 MHz) δ
70.1 (C5), 75.8 (C3), 77.5 (C2), 80.9 (C4), 99.7 (C1, JC1,H1
=
167.9 Hz); 24.4, 24.5, 25.7, 32.0, 33.8, 76.2 (cyclohexyl); MS
(FAB) m/z 525.2617 (M+Na)+.
Calcd for C32H38O5Na:
525.26168.
6b: [α]D23 −1.3° (c 1.4, CHCl3); 1H NMR (CDCl3, 300 MHz) δ
3.53 (dd, J4,5a = 6 Hz, J5a,5b = 10.5 Hz, H5a), 3.61 (dd, J4,5b = 4
Hz, J5a,5b = 10.5 Hz, H5b), 3.85 (dd, J1,2 = 1.5 Hz, J2,3 = 5 Hz,
H2), 4.02 (dd, J2,3 = 5 Hz, J3,4 = 6.5 Hz, H3), 4.33 (ddd, J3,4
=
L-Rhamnose (35, monohydrate) and NaH (ca. 60% dispersion
in oil) were products of Wako Pure Chemicals Industries. Com-
pounds 1,7 2,9 3,10 4,11 and 2713 were prepared by known methods.
Trimethylsilyl bromide (Me3SiBr), CoBr2, and tetrabutylammno-
mium bromide (Bu4NBr) were products from Wako Pure Chemi-
cals Industries. Molecular sieves, 4A, powder (MS4A) was
bought from Hydrus Chemical, Inc.
The preparation of the acetates of 23, 24, 25, 26, 28, 31, 32, 34,
37, and 40 was carried out as follows: a sample (ca. 20 mg) was
treated with Ac2O (0.2 mL) and pyridine (0.2 mL) containing one
drop of Et3N, at room temp overnight, quenched with EtOH (0.2
mL) at 20 °C, evaporated to dryness, and chromatographed using
the HE system (3:1) to give a chromatographically pure acetate.
All of the thus-obtained acetates were usable for determining thier
NMR spectra without their elemental analyses.
Glycosylation. To a vessel containing a donor (1.0–1.3 eq),
an acceptor, CoBr2 (1.3 eq), Bu4NBr (1.3 eq), MS4A (2.0 mg/mg
of donor), and solvent (5–10 mL/mmol of acceptor), TMSBr (1.3
eq) was added under stirring at room temp (ca. 25 °C). The mix-
ture was stirred for 16–24 h under anhydrous conditions. To the
mixture, PhMe and NaHCO3 were added; the mixture was then
stirred for 15 min and transferred onto a silica-gel column, which
was subsequently eluted with the TK system (gradient) to give a
anomeric mixture of glycosides. This was further separated with
the solvent system specified below. The results are summarized in
Tables 1 and 2.
6.5 Hz, J4,5a = 6.0 Hz, J4,5b = 4 Hz, H4), 5.18 (d, J1,2 = 1.5 Hz,
H1); 13C NMR (CDCl3, 75 MHz) δ 71.8 (C5), 78.9 (C3), 80.2
(C4), 80.4 (C2), 103.3 (C1, JC1,H1 = 171.0 Hz); 24.0, 24.2, 25.7,
31.5, 33.6, 75.2 (cyclohexyl).
Found: C, 76.21; H, 7.61%. Calcd for C32H38O5: C, 76.46; H,
7.62%.
Methyl O-(2,3,5-Tri-O-benzyl-α- and β-D-ribofuranosyl-
(1→6)-2,3,4-tri-O-benzyl-β-D-glucopyranosides (7a and 7b).
7a (the slower-moving (TK 20:1)): [α]D20 +34° (c 0.5, CHCl3); 1H
NMR (CDCl3, 300 MHz) δ 3.34 (dd, J1,2 = 8 Hz, J2,3 = 9 Hz,
Ⅰ
Ⅰ
H2 ), 3.38 (ddd, J4,5 = 9 Hz, J5,6a = 2 Hz, J5,6b = 4 Hz, H5 ), 3.45
Ⅱ
(dd, J4,5a = 4 Hz, J5a,5b = 10.5 Hz, H5a ), 3.48 (dd, J4,5b = 4 Hz,
Ⅱ
J5a,5b = 10.5 Hz, H5b ), 3.53 (s, Me), 3.60 (t, J2,3 = J3,4 = 9Hz,
Ⅰ
Ⅰ
H3 ), 3.73 (t, J3,4 = J4,5 = 9 Hz, H4 ), 3.80 (dd, J5,6a = 2 Hz, J6a,6b
Ⅰ
Ⅱ
= 11.5Hz, H6a ), 3.88 (dd, J1,2 = 3 Hz, J2,3 = 3.5 Hz, H2 ), 3.89
(dd, J2,3 = 3.5 Hz, J3,4 = 7 Hz, H3 ), 4.11 (dd, J5,6b = 4 Hz, J6a,6b
Ⅱ
Ⅰ
Ⅱ
= 11.5 Hz, H6b ), 4.24 (dt, J3,4 = 7 Hz, J4,5a = J4,5b = 4 Hz, H4 ),
4.30 (d, J1,2 = 8 Hz, H1 ), 5.17 (d, J1,2 = 3 Hz, H1 ); 13C NMR
Ⅰ
Ⅱ
Ⅰ
Ⅱ
Ⅰ
(CDCl3, 75 MHz) δ 56.9 (Me), 66.8 (C6 ), 70.0 (C5 ), 74.7 (C5 ),
76.2 (C3 ), 77.8 (C4 ), 78.0 (C2 ), 81.5 (C4 ), 82.4 (C2 ), 84.6
(C3 ), 102.2 (C1 , JC1,H1 = 169.5 Hz), 104.6 (C1 , JC1,H1 = 159.1
Ⅱ
Ⅰ
Ⅱ
Ⅱ
Ⅰ
Ⅰ
Ⅱ
Ⅰ
Hz).
7b: [α]D21 +8° (c 0.8, CHCl3); H NMR (CDCl3, 300 MHz) δ
1
Ⅰ
Ⅰ
3.39 (m, H5 ), 3.42 (t, J1,2 = J2,3 = 8 Hz, H2 ), 3.45 (dd, J3,4 = 8
Hz, J4,5 = 9 Hz, H4 ), 3.51 (s, Me), 3.56 (dd, J4,5a = 6.5 Hz, J5a,5b
= 10.5 Hz, H5a ), 3.60 (t, J2,3 = J3,4 = 8 Hz, H3 ), 3.63 (dd, J4,5b
= 4 Hz, J5a,5b = 10.5 Hz, H5b ), 3.90 (dd, J1,2 = 1 Hz, J2,3 = 4.5
Ⅰ
Ⅱ
Ⅰ
Ⅱ
Cylohexylmethyl 2,3,5-Tri-O-benzyl-α- and β-D-ribofura-
nosides (5a and 5b). 5a (the slower-moving (TK 20:1)): [α]D
+57° (c 0.3, CHCl3); 1H NMR (CDCl3, 300 MHz) δ 3.39 (dd, J4,5a
Ⅱ
Ⅱ
Hz, H2 ), 4.05 (dd, J2,3 = 4.5 Hz, J3,4 = 6.5 Hz, H3 ), 4.26 (d, J1,2
Ⅰ
Ⅱ
= 8 Hz, H1 ), 4.36 (dt, J3,4 = J4,5a = 6.5 Hz, J4,5b = 4 Hz, H4 ),
5.10 (d, J1,2 = 1 Hz, H1 ); 13C NMR (CDCl3, 75 MHz) δ 56.9
Ⅱ
= 4 Hz, J5a,5b = 10.5 Hz, H5a), 3.47 (dd, J4,5b = 4 Hz, J5a,5b
=
Ⅰ
Ⅱ
Ⅰ
Ⅰ
Ⅱ
10.5 Hz, H5b), 3.78 (dd, J1,2 = 4 Hz, J2,3 = 6.5 Hz, H2), 3.84 (dd,
J2,3 = 6.5 Hz, J3,4 = 4 Hz, H3), 4.22 (dt, J3,4 = J4,5a = J4,5b = 4
Hz, H4), 4.98 (d, J1,2 = 4 Hz, H1); 13C NMR (CDCl3, 75 MHz) δ
(Me), 66.8 (C6 ), 71.7 (C5 ), 74.4 (C5 ), 78.1 (C4 ), 78.9 (C3 ),
79.9 (C2 ), 80.7 (C4 ), 82.3 (C2 ), 84.6 (C3 ), 104.5 (C1 , JC1,H1
155.9 Hz), 105.8 (C1 , JC1,H1 = 171.6 Hz). Found: 7a: C, 74.22;
H, 6.89%. 7b: C, 74.47; H, 6.84%. Calcd for C54H58O10: C,
74.80; H, 6.74%.
Ⅱ
Ⅱ
Ⅰ
Ⅰ
Ⅰ
=
Ⅱ
70.2 (C5), 75.8 (C3), 77.7 (C2), 81.3 (C4), 101.6 (C1, JC1,H1
=
170.4 Hz); 25.8, 25.9, 26.7, 30.2 (2C), 37.8, 74.0 (cyclohexylme-
thyl); MS (FAB) m/z 539.2773 (M+Na)+. Calcd for C33H40O5Na:
539.27733.
Methyl O-(2,3,5-Tri-O-benzyl-α- and β-D-ribofuranosyl-
(1→4)-2,3,6-tri-O-benzyl-β-D-glucopyranosides (8a and 8b).
8a (the slower-moving (TK 20:1)): [α]D +31° (c 0.7, CHCl3); 1H
NMR (CDCl3, 300 MHz) δ 3.42 (dd, J1,2 = 8 Hz, J2,3 = 9 Hz,
5b: [α]D23 +17° (c 1.9, CHCl3); 1H NMR (CDCl3, 300 MHz) δ
3.52 (dd, J4,5a = 6 Hz, J5a,5b = 10.5 Hz, H5a), 3.61 (dd, J4,5b = 4
Hz, J5a,5b = 10.5 Hz, H5b), 3.87 (dd, J1,2 = 1 Hz, J2,3 = 4.5 Hz,
Ⅰ
Ⅱ
H2 ), 3.61 (s, Me), 3.66 (dd, J1,2 = 4.5 Hz, J2,3 = 6.5 Hz, H2 ),

M. Hirooka et al.
3.74 (dd, J2,3 = 6.5 Hz, J3,4 = 2 Hz, H3 ), 3.77 (t, J3,4 = J4,5 = 9
Bull. Chem. Soc. Jpn., 74, No. 9 (2001) 1685
Ⅱ
(CDCl3, 300 MHz) δ 1.37 (d, J5,6 = 6 Hz, H6), 3.30 (dq, J4,5 = 9.5
Hz, J5,6 = 6 Hz, H5), 3.45 (dd, J2,3 = 3 Hz, J3,4 = 9.5 Hz, H3),
3.62 (t, J3,4 = J4,5 = 9.5 Hz, H4), 3.85 (dd, J1,2 = 0.5 Hz, J2,3 = 3
Hz, H2), 4.47 (d, J1,2 = 0.5 Hz, H1); 13C NMR (CDCl3, 75 MHz)
δ 18.1 (C6), 71.9 (C5), 74.6 (C2), 80.3 (C4), 82.5 (C3), 99.2 (C1,
JC1,H1 = 152.7 Hz); 23.7, 23.8, 25.8, 31.5, 33.4, 76.2 (cyclohexyl).
Found: 11a, C, 76.28; H, 7.81%. 11b, C, 76.86; H, 7.99%.
Calcd for C33H40O5: C, 76.71; H, 7.80%.
Ⅰ
Ⅰ
Hz, H4 ), 3.82 (t, J2,3 = J3,4 = 9 Hz, H3 ), 4.08 (dt, J3,4 = 2 Hz,
Ⅱ
Ⅰ
J4,5a = J4,5b = 4 Hz, H4 ), 4.35 (d, J1,2 = 8 Hz, H1 ), 5.56 (d, J1,2
= 4.5 Hz, H1 ); 13C NMR (CDCl3, 75 MHz) δ 57.1 (Me), 70.1
(C6 ), 70.3 (C5 ), 74.2 (C5 ), 74.3 (C4 ), 75.0 (C3 ), 77.3 (C2 ),
82.3 (C4 ), 82.4 (C2 ), 84.4 (C3 ), 101.8 (C1 , JC1,H1 = 175.2 Hz),
Ⅱ
Ⅰ
Ⅱ
Ⅰ
Ⅰ
Ⅱ
Ⅱ
Ⅱ
Ⅰ
Ⅰ
Ⅱ
Ⅰ
104.6 (C1 , JC1,H1 = 158.1 Hz); MS (FAB) m/z 889.3928
(M+Na)+. Calcd for C54H58O10Na: 889.39273.
8b: [α]D21 +9° (c 9, CHCl3); 1H NMR (CDCl3, 300 MHz) δ 3.39
Methyl O-(2,3,4-Tri-O-benzyl-α- and β-L-rhamnopyranos-
yl-(1→6)-2,3,4-tri-O-benzyl-β-D-glucopyranosides (12a and
12b). 12a (the faster-moving (TK 20:1)): [α]D23 −17° (c 0.3,
CHCl3) (Ref. 21a [α]D16 −12.9° (c 2.05, CHCl3)); 1H NMR
Ⅰ
(dd, J1,2 = 7.5 Hz, J2,3 = 9 Hz, H2 ), 3.40 (ddd, J4,5 = 9 Hz, J5,6a
4 Hz, J5,6b = 2 Hz, H5 ), 3.48 (d, J4,5 = 5 Hz, H5 ), 3.56 (s, Me),
3.59 (t, J2,3 = J3,4 = 9 Hz, H3 ), 3.64 (dd, J5,6a = 4 Hz, J6a,6b = 11
Hz, H6a ), 3.70 (t, J3,4 = J4,5 = 9 Hz, H4 ), 3.73 (dd, J5,6b = 2 Hz,
=
Ⅰ
Ⅱ
Ⅰ
Ⅰ
Ⅰ
Ⅱ
(CDCl3, 300 MHz) δ 1.36 (d, J5,6 = 6 Hz, H6 ), 3.43 (t, J1,2 = J2,3
Ⅰ
Ⅱ
Ⅰ
Ⅰ
J6a,6b = 11 Hz, H6b ), 3.82 (dd, J1,2 = 3 Hz, J2,3 = 5 Hz, H2 ),
=8 Hz, H2 ), 3.435 (dd, J3,4 = 8 Hz, J4,5 = 9 Hz, H4 ), 3.440 (m,
Ⅱ
Ⅱ
Ⅰ
3.93 (t, J2,3 = J3,4 = 5 Hz, H3 ), 4.23 (dt, J3,4 = J4,5 = 5 Hz, H4 ),
H5 ), 3.54 (s, Me), 3.56 (dd, J5,6a = 6.5 Hz, J6a,6b = 11.5 Hz,
4.27 (d, J1,2 = 7.5 Hz, H1 ), 5.38 (d, J1,2 = 3 Hz, H1 ); 13C NMR
H6a ), 3.665 (t, J3,4 = J4,5 = 9 Hz, H4 ), 3.668 (t, J2,3 = J3,4 = 8
Ⅰ
Ⅱ
Ⅰ
Ⅱ
Ⅰ
Ⅱ
Ⅰ
Ⅰ
Ⅱ
(CDCl3, 75 MHz) δ 56.9 (Me), 69.1 (C6 ), 70.9 (C5 ), 74.9 (C5 ),
76.7 (C4 ), 77.4 (C3 ), 80.4 (C2 ), 80.5 (C4 ), 82.3 (C2 ), 83.1
(C3 ), 104.6 (C1 , JC1,H1 = 154.2 Hz, 106.5 (C1 , JC1,H1 = 169.0
Hz).
Hz, H3 ), 3.76 (t, J1,2 = 2 Hz, J2,3 = 3 Hz, H2 ), 3.81 (dq, J4,5 = 9
Ⅰ
Ⅱ
Ⅱ
Ⅱ
Ⅰ
Ⅱ
Ⅱ
Hz, J5,6 = 6 Hz, H5 ), 3.92 (dd, J2,3 = 3 Hz, J3,4 = 9 Hz, H3 ),
Ⅰ
Ⅰ
Ⅱ
Ⅰ
3.93 (dd, J5,6b = 5 Hz, J6a,6b = 11.5 Hz, H6b ), 4.31 (d, J1,2 = 8
Hz, H1 ), 4.80 (d, J1,2 = 2 Hz, H1 ); 13C NMR (CDCl3, 75 MHz) δ
Ⅰ
Ⅱ
Ⅱ
Ⅰ
Ⅱ
Ⅰ
Found: C, 74.13; H, 6.79%. Calcd for C54H58O10: C, 74.80; H,
6.74%.
18.0 (C6 ), 56.8 (Me), 66.5 (C6 ), 68.1 (C5 ), 74.3 (C5 ), 75.2
Ⅱ
Ⅰ
Ⅱ
Ⅱ
Ⅰ
Ⅰ
(C2 ), 78.0 (C4 ), 79.9 (C3 ), 80.6 (C4 ), 82.3 (C2 ), 84.6 (C3 ),
Ⅱ
Methyl 2,3,5-Tri-O-benzyl-β-D-ribofuranoside (9). In the
case of Run 5, 9 (8%) was eluted before the appearance of 7b:
[α]D25 +23° (c 0.5, 1,4-dioxane) (Ref. 7, [α]D20 +22.4° (c 3.6, 1,4-
98.5 (C1 , JC1,H1 = 167.0 Hz), 104.5 (C1I, JC1,H1 = 158.5 Hz).
12b:[α]D23 +24° (c 0.4, CHCl3); 1H NMR (CDCl3, 300 MHz) δ
Ⅱ
Ⅱ
1.37 (d, J5,6 = 6 Hz, H6 ), 3.33 (dq, J4,5 = 9 Hz, J5,6 = 6 Hz, H5 ),
3.37 (ddd, J4,5 = 9 Hz, J5,6a = 2 Hz, J5,6b = 3 Hz, H5 ), 3.40 (t, J1,2
= J2,3 = 8 Hz, H2 ), 3.47 (dd, J2,3 = 3 Hz, J3,4 = 9 Hz, H3 ), 3.56
(s, Me), 3.61 (t, J3,4 = J4,5 = 9 Hz, H4 ), 3.64 (dd, J2,3 = 8 Hz, J3,4
= 9 Hz, H3 ), 3.71 (t, J3,4 = J4,5 = 9 Hz, H4 ), 3.78 (dd, J5,6a = 2
Hz, J6a,6b = 11.5 Hz, H6a ), 4.00 (d, J1,2 = 0 Hz, J2,3 = 3 Hz, H2 ),
1
Ⅰ
dioxane)); H NMR (CDCl3, 300 MHz) δ 3.32 (s, Me), 3.51 (dd,
Ⅰ
Ⅱ
J4,5a = 6 Hz, J5a,5b = 10.5 Hz, H5a), 3.61 (dd, J4,5b = 4 Hz, J5a,5b
=
Ⅱ
10.5 Hz, H5b), 3.83 (dd, J1,2 = 1 Hz, J2,3 = 4.5 Hz, H2), 4.02 (dd,
J2,3 = 4.5 Hz, J3,4 = 7 Hz, H3), 4.34 (ddd, J3,4 = 7 Hz, J4,5a = 6
Hz, J4,5b = 4 Hz, H4), 4.92 (d, J1,2 = 1 Hz, H1); 13C NMR (CDCl3,
75 MHz) δ 55.1 (Me), 71.4 (C5), 78.5 (C3), 79.8 (C2), 80.5 (C4),
106.4 (C1); MS (FAB) m/z 457 (M+Na)+.
Ⅰ
Ⅰ
Ⅰ
Ⅱ
Ⅰ
4.26 (dd, J5,6b = 3 Hz, J6a,6b = 11.5 Hz, H6b ), 4.30 (d, J1,2 = 8
Ⅰ
Ⅱ
Ⅱ
Hz, H1 ), 4.50 (s, H1 ); 13C NMR (CDCl3, 75 MHz) δ 18.0 (C6 ),
Ⅰ
Ⅱ
Ⅱ
Ⅰ
Cyclohexylmethyl 2,3,4-Tri-O-benzyl-α- and β-L-rhamno-
57.2 (Me), 67.1 (C6 ), 72.0 (C5 ), 74.0 (C2 ), 74.6 (C5 ), 77.7
Ⅰ
Ⅱ
Ⅱ
Ⅰ
Ⅰ
Ⅱ
pyranosides (10a and 10b).
10a (the faster-moving (TK
(C4 ), 80.3 (C4 ), 82.2 (C3 ), 82.4 (C2 ), 84.5 (C3 ), 101.6 (C1 ,
JC1,H1 = 152.9 Hz), 104.9 (C1 , JC1,H1 = 153.7 Hz).
20:1)): [α]D19 −2.5° (c 1.8, CHCl3); 1H NMR (CDCl3, 300 MHz) δ
1.32 (d, J5,6 = 6 Hz, H6), 3.61 (t, J3,4 = J4,5 = 9 Hz, H4), 3.65 (dq,
J4,5 = 9 Hz, J5,6 = 6 Hz, H5), 3.75 (dd, J1,2 = 2 Hz, J2,3 = 3 Hz,
H2), 3.85 (dd, J2,3 = 3 Hz, J3,4 = 9.0 Hz, H3), 4.70 (d, J1,2 = 2 Hz,
H1); 13C NMR (CDCl3, 75 MHz) δ 18.0 (C6), 68.0 (C5), 75.3
(C2), 80.3 (C3), 80.7 (C4), 98.1 (C1, JC1,H1 = 165.8 Hz); 25.8,
25.9, 26.6, 29.9, 30.1, 37.9, 73.1 (cyclohexylmethyl).
Found: C, 77.05; H, 8.23%. Calcd for C34H42O5: C, 76.95; H,
7.98%.
Ⅰ
Found: 12a, C, 75.04; H, 6.99%. 12b, C, 74.69; H, 6.96%.
Calcd for C55H60O10: C, 74.98; H, 6.86%.
Methyl O-(2,3,4-Tri-O-benzyl-α-L-rhamnopyranosyl-(1→4)
-2,3,6-tri-O-benzyl-β-D-glucopyranosides (13).
[α]D20 −17°
(c 2.4, CHCl3) (Ref. 4a and 21b, [α]D20 −23° (c 2, CHCl3),
[α]D20 −15° (c 1, CHCl3)); 1H NMR (CDCl3, 300 MHz) δ 1.08 (d,
J5,6 = 6 Hz, H6 ), 3.35 (ddd, J4,5 = 9 Hz, J5,6a = 4 Hz, J5,6b = 2
Ⅱ
Ⅰ
Ⅰ
Hz, H5 ), 3.502 (dd, J1,2 = 7.5 Hz, J2,3 = 8 Hz, H2 ), 3.503 (dd,
10b: mp 80–83 °C; [α]D +35° (c 1.0, CHCl3); 1H NMR
J5,6a = 4 Hz, J6a,6b = 10.5 Hz, H6a ), 3.53 (dd, J2,3 = 8 Hz, J3,4 = 9
Ⅰ
Ⅰ
Ⅱ
(CDCl3, 300 MHz) δ = 1.39 (d, J5,6 = 6 Hz, H6), 3.31 (dq, J4,5
=
Hz, H3 ), 3.58 (s, Me), 3.59 (t, J3,4 = J4,5 = 9.5 Hz, H4 ), 3.62 (dd,
Ⅰ
9.5 Hz, J5,6 = 6 Hz, H5), 3.45 (dd, J2,3 = 3 Hz, J3,4 = 9.5 Hz, H3),
3.63 (t, J3,4 = J4,5 = 9.5 Hz, H4), 3.91 (d, J1,2 = 0 Hz, J2,3 = 3 Hz,
H2), 4.31 (s, H1); 13C NMR (CDCl3, 75 MHz) δ 18.0 (C6), 72.0
(C5), 74.0 (C2), 80.3 (C4), 82.4 (C3), 102.0 (C1, JC1,H1 = 151.7
Hz); 25.9 (2C), 26.6, 29.9, 30.2, 38.2, 75.7 (cyclohexylmethyl);
MS (FAB) m/z 553.2930 (M+Na)+. Calcd for C34H42O5Na:
553.29297.
J5,6b = 2 Hz, J6a,6b = 10.5 Hz, H6b ), 3.73 (dd, J1,2 = 2 Hz, J2,3 =
Ⅱ
Ⅰ
3 Hz, H2 ), 3.79 (t, J3,4 = J4,5 = 9 Hz, H4 ), 3.83 (dd, J2,3 = 3 Hz,
Ⅱ
Ⅱ
J3,4 = 9.5 Hz, H3 ), 3.93 (dq, J4,5 = 9.5 Hz, J5,6 = 6 Hz, H5 ),
Ⅰ
Ⅱ
4.31 (d, J1,2 = 7.5 Hz, H1 ), 5.09 (d, J1,2 = 2 Hz, H1 ); 13C NMR
Ⅱ
Ⅱ
Ⅰ
(CDCl3, 75 MHz) δ 17.8 (C6 ), 56.9 (Me), 68.7 (C5 ), 69.0 (C6 ),
Ⅱ
Ⅰ
Ⅰ
Ⅱ
Ⅱ
75.10 (C2 ), 75.14 (C5 ), 75.4 (C4 ), 79.7 (C3 ), 80.7 (C4 ), 82.6
Ⅰ
Ⅰ
Ⅰ
(C2 ), 82.7 (C3 ), 98.4 (JC1,H1 = 167.6 Hz), 104.7 (C1 , JC1,H1
=
Cylohexyl 2,3,4-Tri-O-benzyl-α- and β-L-rhamnopyrano-
158.2 Hz).
sides (11a and 11b). 11a (the faster-moving (TK 20:1)): [α]D24
Found: C, 75.10; H, 7.03%. Calcd for C55H60O10: C, 74.98; H,
6.86%.
1
−20° (c 0.9, CHCl3); H NMR (CDCl3, 300 MHz) δ 1.32 (d, J5,6
= 6 Hz, H6), 3.61 (t, J3,4 = J4,5 = 9.5 Hz, H4), 3.72 (dd, J1,2 = 2
Hz, J2,3 = 3 Hz, H2), 3.77 (dq, J4,5 = 9.5 Hz, J5,6 = 6 Hz, H5),
3.89 (dd, J2,3 = 3 Hz, J3,4 = 9.5 Hz, H3), 4.87 (d, J1,2 = 2 Hz, H1);
13C NMR (CDCl3, 75 MHz) δ 18.0 (C6), 68.1 (C5), 75.8 (C2),
80.3 (C3), 80.8 (C4), 95.8 (C1, JC1,H1 = 164.9 Hz); 23.7, 24.0,
25.7, 31.3, 33.3, 74.6 (cyclohexyl).
The β-(1→4)-linked disaccharide derivative (< 4% in Run 15
Ⅱ
and < 6% in Run 16: 13C NMR (CDCl3, 75 MHz) δ 98.8 (C1 ),
Ⅰ
104.6 (C1 ); MS (FAB) m/z 903 (M+Na)+) could not be isolated
in pure state.
O-(2,3,4-Tri-O-benzyl-α-L-rhamnopyranosyl-(1→1)-2,3,4-
Tri-O-benzyl-α-L-rhamnopyranoside (14). In the case of Run
15, 14 (20%) was eluted after the appearance of 13; [α]D22 −27° (c
11b: mp 80–82 °C; [α]D +15° (c 0.4, CHCl3); 1H NMR

1686 Bull. Chem. Soc. Jpn., 74, No. 9 (2001)
Synthesis of β-D-Ribf-(1→3)-α-L-Rhap-(1→3)-
0.3, CHCl3)# (Ref. 4a, [α]D20 −74° (c 0.9, CHCl3)); 1H NMR
(CDCl3, 300 MHz) δ 1.25 (d, J5,6 = 6 Hz, H6), 3.41 (dq, J4,5 = 9
Hz, J5,6 = 6 Hz, H5), 3.57 (dd, J1,2 = 2 Hz, J2,3 = 3 Hz, H2), 3.59
(t, J3,4 = J4,5 = 9 Hz, H4), 3.67 (dd, J2,3 = 3 Hz, J3,4 = 9.0 Hz,
H3), 4.96 (d, J1,2 = 2 Hz, H1); 13C NMR (CDCl3, 75 MHz) δ 18.0
(C6), 68.7 (C5), 74.4 (C2), 79.5 (C3), 80.4 (C4), 93.5 (C1, JC1,H1
= 168.9 Hz); MS (FAB) m/z 873 (M+Na)+.
4.93 (d, J1,2 = 1 Hz, H1), 5.95 (m, allyl); 13C NMR (CDCl3, 75
MHz) δ 55.0 (Me), 71.2 (C5), 78.3 (C3), 79.8 (C2), 80.4 (C4),
106.4 (C1); 71.4, 117.5, 134.3 (allyl).
Found: C, 71.22; H, 7.33%. Calcd for C23H28O5: C, 71.85; H,
7.34%.
2-O-Allyl-3,5-Di-O-benzyl-β-D-ribofuranose (21). A mix-
ture of 29 (890 mg, 2.3 mmol), aq AcOH (89 mL), and aq H2SO4
(30%, 0.35 mL) was stirred at 80 °C for 1 h. After the mixture
was diluted with H2O (50 mL) and PhMe (100 mL), the organic
layer was washed with aq NaHCO3 (5%) and H2O. Evaporation
and chromatography with the TK system (10:1) afforded 21 (750
mg, 99%); [α]D22 +43° (c 0.9, CHCl3); 1H NMR (CDCl3, 300
Methyl 2,5- and 3,5-Di-O-benzyl-β-D-ribofuranosides (28
and 23). A mixture of 2713 (3.14 g, 12.3 mmol), Bu2SnO (4.13
g, 16.6 mmol), Bu4NBr (4.13 g, 12.8 mmol), BnBr (6.9 mL, 58
mmol), PhH (69 mL), and MS4A (13.8 g) was refluxed for 2 h un-
der stirring. After evaporation to dryness, the residue was chro-
matographed with the TK system (10:1) to give 28 (1.9 g, 45%),
and 23 (2.3 g, 54%).
MHz) (65%α) δ 3.34 (d, J1,OH = 6.5 Hz, 1-OHβ), 3.47 (dd, J4,5a
=
4 Hz, J5a,5b = 10.5 Hz, H5aα), 3.48 (dd, J4,5a = 3 Hz, J5a,5b = 10.5
Hz, H5aβ), 3.52 (dd, J4,5b = 4 Hz, J5a,5b = 10.5 Hz, H5bα), 3.66
(dd, J4,5b = 2.5 Hz, J5a,5b = 10.5 Hz, H5bβ), 3.81 (dd, J1,2 = 1 Hz,
J2,3 = 4 Hz, H2β), 3.94 (dd, J1,2 = 4 Hz, J2,3 = 5 Hz, H2α), 4.01
(dd, J2,3 = 5 Hz, J3,4 = 2.5 Hz, H3α), 4.14 (d, J1,OH = 10 Hz, 1-
OHα), 4.23 (dd, J2,3 = 4 Hz, J3,4 = 7 Hz, H3β), 4.28 (ddd, J3,4 = 7
Hz, J4,5a = 3 Hz, J4,5b = 2.5 Hz, H4β), 4.36 (dt, J3,4 = 2.5 Hz, J4,5a
= J4,5b = 4 Hz, H4α), 5.28 (dd, J1,2 = 1 Hz, J1,OH = 6.5 Hz, H1β),
5.31 (dd, J1,2 = 4 Hz, J1,OH = 10.0 Hz, H1α); 13C NMR (CDCl3,
75 MHz) δ 69.4 (C5β), 70.0 (C5α), 77.2 (C3β), 77.7 (C3α), 77.8
(C2α), 80.8 (C2β), 80.9 (C4α), 81.0 (C4β), 96.2 (C1α), 100.4
(C1β), 71.5, 117.7, 134.1 (allyl-α), 71.5, 117.6, 134.4 (allyl-β),
72.8, 73.5 (benzyl-α), 72.5, 73.5 (benzy-β).
23: [α]D25 −23° (c 0.5, CHCl3) (Ref. 22, [α]D +17.4° (c 0.4,
1
CHCl3)); H NMR (CDCl3, 300 MHz) δ 2.71 (d, J2,OH = 3 Hz,
OH), 3.32 (s, Me), 3.55 (2H, d, J4,5 = 5.5 Hz, H5), 4.03 (dd, J1,2
0 Hz, J2,3 = 5 Hz, J2,OH = 3 Hz, H2); 4.08 (dd, J2,3 = 5 Hz, J3,4
=
=
6 Hz, H3), 4.24 (dt, J3,4 = 6 Hz, J4,5 = 5.5 Hz, H4), 4.87 (s, H1);
13C NMR (CDCl3, 75 MHz) δ 55.0 (Me), 71.6 (C5), 73.4 (C2),
79.6 (C3), 80.6 (C4), 108.6 (C1).
Found: C, 69.97; H, 7.16%. Calcd for C20H24O5: C, 69.75; H,
7.02%.
28: [α]D22 +13° (c 2, CHCl3) (Ref. 23, [α]D20 +4° (c 1, CHCl3));
1H NMR (CDCl3, 300 MHz) δ 2.59 (d, J3,OH = 8.5 Hz, OH), 3.34
(s, Me), 3.55 (dd, J4,5a = 6 Hz, J5a,5b = 11 Hz, H5a), 3.67 (dd, J4,5b
= 4 Hz, J5a,5b = 11 Hz, H5b), 3.87 (dd, J1,2 = 1 Hz, J2,3 = 5 Hz,
H2), 4.10 (dt, J3,4 = J4,5a = 6 Hz, J4,5b = 4 Hz, H4), 4.17 (ddd, J2,3
= 5 Hz, J3,4 = 6 Hz, J3,OH = 8.5 Hz, H3); 4.92 (d, J1,2 = 1 Hz,
H1); 13C NMR (CDCl3, 75 MHz) δ 55.2 (Me), 71.6 (C5), 71.8
(C3), 82.0 (C2), 83.2 (C4), 105.8 (C1); MS (FAB) m/z 367.1521
(M+Na)+. Calcd for C20H24O5Na: 367.15214.
Found: C, 70.17; H, 7.07%. Calcd for C22H26O5•0.5H2O: C,
69.64; H, 7.17%.
Methyl 2- and 3-O-Trityl-α-L-rhamnopynosides (32 and
31). The glycoside 3016 was prepared by a modified methanoly-
sis. A mixture of 35 (monohydrate, 9.0 g, 49 mmol), MeOH (45
mL), and MeSO3H (0.30 mL, 4.6 mmol) was refluxed for 5 h. To
a cooled solution, NaHCO3 (0.60 g) was added. Evaporation and
chromatography with the CM system (10:1) afforded an anomeric
mixture of the pyranosides. This was rechromatographed with the
EM system to give 30 (6.32 g, 72%) as the main product; 1H NMR
(D2O, 300 MHz) δ 1.29 (d, J5,6 = 6 Hz, H6), 3.39 (s, Me), 3.42 (t,
J3,4 = J4,5 = 9.5 Hz, H4), 3.67 (dq, J4,5 = 9.5 Hz, J5,6 = 6 Hz, H5),
3.70 (dd, J2,3 = 3.5 Hz, J3,4 = 9.5 Hz, H3), 3.92 (dd, J1,2 = 2 Hz,
J2,3 = 3.5 Hz, H2), 4.69 (d, J1,2 = 2 Hz, H1); 13C NMR (D2O, 75
MHz) δ 20.6 (C6), 58.1 (Me), 71.8 (C5), 73.4 (C2), 73.7 (C3),
75.5 (C4), 104.3 (C1, JC1,H1 = 170.0 Hz). A mixture of 30 (3.50 g,
19.7 mmol), trityl chloride (10.7 g, 38.4 mmol), and pyridine
(10mL) was stirred at 60 °C for 16 h. After the addition of Et3N
(10 mL),14 the mixture was evaporated to dryness and chromato-
graphed with the TKsystem (3:1) to give 31 (6.277 g, 76%); [α]D20
1
The NMR data of the acetate of 23: H NMR (CDCl3, 300
MHz) δ 2.12 (s, Ac), 3.33 (s, Me), 3.50 (dd, J4,5a = 5.5 Hz, J5a,5b
=
10.5 Hz, H5a), 3.61 (dd, J4,5b = 3.5 Hz, J5a,5b = 10.5 Hz, H5b);
4.13 (dd, J2,3 = 4.5 Hz, J3,4 = 7.5 Hz, H3), 4.22 (ddd, J3,4 = 7.5
Hz, J4,5a = 3.5 Hz, J4,5b = 5.5 Hz, H4), 4.88 (s, H1), 5.20 (d, J1,2
= 0 Hz, J2,3 = 4.5 Hz, H2), 13C NMR (CDCl3, 75 MHz) δ 55.0
(Me), 71.1 (C5), 74.1 (C2), 77.9 (C3), 80.4 (C4), 106.3 (C1), 20.9,
170.0 (Ac).
1
The NMR data of the acetate of 28: H NMR (CDCl3, 300
MHz) δ 2.07 (s, Ac), 3.35 (s, Me), 3.57 (dd, J4,5a = 5.5 Hz, J5a,5b
=
10.5 Hz, H5a), 3.61 (dd, J4,5b = 5 Hz, J5a,5b = 10.5 Hz, H5b), 4.09
(dd, J1,2 = 2 Hz, J2,3 = 5 Hz, H2), 4.34 (dt, J3,4 = J4,5b = 5 Hz,
J4,5a = 5.5 Hz, H4), 4.92 (d, J1,2 = 2 Hz, H1), 5.15 (t, J2,3 = J3,4
=
5 Hz, H3); 13C NMR (CDCl3, 75 MHz) δ 55.4 (Me), 71.2 (C5),
73.4 (C3), 80.3 (C4), 80.9 (C2), 107.0 (C1), 20.8, 170.0 (Ac).
A sample (6.9 mg) of 23 was benzylated with PhCH2Br (24 µL)
and NaH (ca. 60%, 8.0 mg) in DMF (0.20 mL) at 20 °C for 2 h,
followed by quenching with MeOH, evaporation, and chromatog-
raphy, to give 9 quantitatively.
−42° (c 1.7, CHCl3) (Ref. 15, [α]D20 −50.6° (c 2.7, CHCl3)); H
1
NMR (CDCl3, 300 MHz) δ 1.28 (d, J5,6 = 6 Hz, H6), 2.09 (OH),
2.17 (OH), 3.18 (s, Me), 3.45 (dq, J4,5 = 9 Hz, J5,6 = 6Hz, H5),
3.61 (dd, J1,2 = 1.5 Hz, J2,3 = 3 Hz, H2), 3.71 (t, J3,4 = J4,5 = 9
Hz, H4), 3.84 (dd, J2,3 = 3 Hz, J3,4 = 9 Hz, H3), 4.43 (d, J1,2 = 1.5
Hz, H1); 13C NMR (CDCl3, 75 MHz) δ 17.9 (C6), 54.7 (Me), 68.0
(C5), 69.6 (C2), 72.0 (C4), 74.5 (C3), 100.4 (C1); 87.5 (trityl);
MS (FAB) m/z 443.1834 (M+Na)+. Calcd for C26H28O5Na:
443.18344.
Methyl 2-O-Allyl-3,5-Di-O-benzyl-β-D-ribofuranosides (29).
A mixture of 23 (1.097 g, 3.2 mmol), NaH (60% in oil, 0.20 g, 6.5
mmol), and allyl bromide (10 mL) was stirred at 80 °C for 2 h.
Evaporation and chromatography with the TK system (20:1) af-
forded 29 (1.073 g, 88%), [α]D22 +11° (c 1.2, CHCl3); H NMR
Further elution gave 32 (0.224 mg, 7.5%); [α]D20 +52° (c 0.5,
1
CHCl3) (Ref. 15, [α]D20 +45° (c 1.1, CHCl3)); H NMR (CDCl3,
1
(CDCl3, 300 MHz) δ 3.35 (s, Me), 3.53 (dd, J4,5a = 6 Hz, J5a,5b
=
10.5 Hz, H5a), 3.63 (dd, J4,5b = 4 Hz, J5a,5b = 10.5 Hz, H5b), 3.81
(dd, J1,2 = 1 Hz, J2,3 = 5 Hz, H2), 4.05 (dd, J2,3 = 5 Hz, J3,4 = 7
Hz, H3), 4.33 (ddd, J3,4 = 7 Hz, J4,5a = 6 Hz, J4,5b = 4 Hz, H4),
300 MHz) δ 1.33 (d, J5,6 = 6 Hz, H6), 2.50–2.55 (2H, OH), 3.37
(s, Me), 3.44 (t, J3,4 = J4,5 = 9.5 Hz, H4), 3.64 (dq, J4,5 = 9.5 Hz,
J5,6 = 6 Hz, H5), 3.74 (dd, J2,3 = 3.5 Hz, J3,4 = 9.5 Hz, H3), 3.92
(dd, J1,2 = 1.5 Hz, J2,3 = 3.5 Hz, H2), 4.67 (d, J1,2 = 1.5 Hz, H1);
13C NMR (CDCl3, 75 MHz) δ 17.5 (C6), 54.9 (Me), 67.6 (C5),
# The previous value4a was corrected.

M. Hirooka et al.
Bull. Chem. Soc. Jpn., 74, No. 9 (2001) 1687
70.9 (C2), 71.9 (C3), 73.6 (C4), 100.7 (C1, JC1,H1 = 167 Hz).
Found: C, 73.65; H, 6.85%. Calcd for C26H28O5: C, 74.26; H,
6.71%.
8.6 mmol), Bu2SnO (2.4 g, 9.6 mmol), and MeOH (100 mL) was
stirred at 75 °C under reflux for 80 min. After evaporation to dry-
ness, the residue was heated in DMF (65 mL) containing allyl bro-
mide (3.8 mL, 45 mmol) at 65 °C under stirring for 16 h. After
evaporation to dryness on a boiling water-bath, the residue was
chromatographed with the CM system (10:1) to give methyl 3-O-
allyl-α-L-rhamnopynoside (34) (1.03 g, 55%); [α]D22 −28° (c 0.4,
H2O) (Ref. 24, [α]D23 −39.18° (c 1.1, H2O)); 1H NMR (CDCl3, 300
1
The NMR data of the acetate of 31 was as follows: H NMR
(CDCl3, 300 MHz) δ 1.14 (d, J5,6 = 6 Hz, H6); 1.89, 2.22 (s, Ac),
3.15 (s, Me), 3.50 (dq, J4,5 = 9.5 Hz, J5,6 = 6 Hz, H5), 3.91 (dd,
J2,3 = 3.5 Hz, J3,4 = 9.5 Hz, H3), 4.20 (dd, J1,2 = 2 Hz, J2,3 = 3.5
Hz, H2), 4.47 (d, J1,2 = 2 Hz, H1), 5.30 (t, J3,4 = J4,5 = 9.5 Hz,
H4); 13C NMR (CDCl3, 75 MHz) δ 17.7 (C6), 66.7 (C5), 69.5
(C3), 71.9 (C2), 72.4 (C4), 97.8 (C1); 21.2, 21.3, 170.2 (2C) (Ac);
54.9 (Me), 87.4 (trityl).
MHz) δ 1.30 (d, J5,6 = 6 Hz, H6), 2.65 (s, OH), 3.521 (dd, J2,3
=
2.5 Hz, J3,4 = 9 Hz, H3), 3.523 (s, Me), 3.53 (t, J3,4 = J4,5 = 9 Hz,
H4), 3.62 (dq, J4,5 = 9 Hz, J5,6 = 6 Hz, H5), 3.89 (dd, J1,2 = 1.5
Hz, J2,3 = 2.5 Hz, H2), 4.68 (d, J1,2 = 1.5 Hz, H1); 13C NMR
(CDCl3, 75 MHz) δ 17.6 (C6), 54.8 (Me), 67.6 (C5), 67.7 (C2),
71.4 (C4), 79.3 (C3), 100.4 (C1); 70.4, 118.0, 134.3 (allyl); MS
1
The NMR data of the acetate of 32 was as follows: H NMR
(CDCl3, 300 MHz) δ 1.29 (d, J5,6 = 6 Hz, H6); 1.93, 2.06 (s, Ac),
3.00 (s, Me), 3.55 (d, J1,2 = 1.5 Hz, H1), 3.75 (dq, J4,5 = 10 Hz,
J5,6 = 6 Hz, H5), 3.92 (dd, J1,2 = 1.5 Hz, J2,3 = 3.5 Hz, H2), 5.13
(dd, J2,3 = 3.5 Hz, J3,4 = 10 Hz, H3), 5.47 (t, J3,4 = J4,5 = 10 Hz,
H4); 13C NMR (CDCl3, 75 MHz) δ 17.9 (C6), 66.3 (C5), 70.7
(C3), 71.8 (C2), 71.9 (C4), 99.3 (C1, JC1,H1 = 170 Hz); 20.9, 21.0,
170.0 (2C) (Ac); 55.0 (Me), 87.9 (trityl).
(FAB) m/z 241.1052 (M+Na)+.
Calcd for C10H18O5Na:
241.1052.
1
The NMR data of the acetate of 34 was as follows: H NMR
(CDCl3, 300 MHz) δ 1.20 (d, J5,6 = 6 Hz, H6), 2.07, 2.12 (s, Ac),
3.35 (s, Me), 3.73 (dd, J2,3 = 3 Hz, J3,4 = 10 Hz, H3), 3.77 (dq,
J4,5 = 10 Hz, J5,6 = 6 Hz, H5), 4.62 (d, J1,2 = 1.5 Hz, H1), 4.98 (t,
J3,4 = J4,5 = 10 Hz, H4), 5.25 (dd, J1,2 = 1.5 Hz, J2,3 = 3 Hz, H2),
5.79 (m, allyl); 13C NMR (CDCl3, 75 MHz) δ 17.4 (C6), 55.0
(Me), 66.3 (C5), 68.7 (C2), 72.5 (C4), 74.4 (C3), 98.7 (C1), 20.9,
21.0, 169.9, 170.3 (Ac).
Methyl 2,4-Di-O-benzyl-α-l-rhamnopyranosides (24). To a
mixture of 31 (1.525 g, 3.6 mmol), PhCH2Br (3.0 mL, 25 mmol),
and DMF (19 mL), NaH (60% in oil, 0.93 mg, 23 mmol) was add-
ed at 0 °C and the mixture was stirred for 15 min. The mixture
was then stirred for 20 °C for 1 h. To the mixture, MeOH (4 mL)
was added at 0 °C under stirring. After stirring at 20 °C for 1 h,
the mixture was evaporated and chromatographed with the TK
system (20:1) to give chromatographically pure benzyl ether (2.45
g). This was treated with CF3CO2H (2.0 mL, 27 mmol) in CH2Cl2
(29 mL) containing MeOH (5 mL) at room temp for 1 h. Evapora-
tion at 25 °C and chromatography with the TK system (5:1) af-
forded 24 (1.074 g, 83%), [α]D22 −13° (c 2.1,CHCl3) (Ref. 24,
To a mixture of 34 (2.00 g, 92 mmol), PhCH2Br (2.4 mL, 20
mmol), and DMF (10 mL), NaH (60% in oil, 0.80 g, 20 mmol)
was added at 0 °C, and the mixture was stirred for 15 min. The
mixture was then stirred for 20 °C for 1 h, followed by quenching
with MeOH (0.4 mL) and chromatography with the TK system, as
described above, to give 33 (2.50 g, 68%).
3-O-Allyl-2,4-Di-O-benzyl-L-rhamnopyranose (22).
A
1
[α]D23 −15.42° (c 1.1, CHCl3)); H NMR (CDCl3, 300 MHz) δ
mixture of 33 (2.40 g, 60 mmol), aq AcOH (25 mL), and aq
H2SO4 (30%, 0.5 mL) was stirred at 85 °C for 1 h. After dilution
with H2O (50 mL) and PhMe (100 mL), the separated organic lay-
er was washed with aq NaHCO3 (5%). Evaporation and chroma-
tography using the HE system (2:1) afforded 22 (1.39 g, 60%),
[α]D21 −15° (c 0.5, CHCl3)# (Ref. 9, [α]D −22° (c 1.0, CHCl3)); 1H
NMR (CDCl3, 300 MHz) (60%α) δ 1.31 (d, J5,6 = 6 Hz, H6α),
1.34 (d, J5,6 = 6 Hz, H6β), 2.65 (d, J1,OH = 3 Hz, OH-1α), 3.35
(dq, J4,5 = 9 Hz, J5,6 = 6 Hz, H5β), 3.47 (dd, J2,3 = 3 Hz, J3,4 = 9
Hz, H3α), 3.53 (t, J3,4 = J4,5 = 9 Hz, H4β), 3.59 (t, J3,4 = J4,5 = 9
Hz, H4α), 3.61 (dd, J2,3 = 2 Hz, J3,4 = 9 Hz, H3β), 3.80 (dd, J1,2
= 1.5 Hz, J2,3 = 3 Hz, H2α), 3.85 (dd, J1,2 = 1 Hz, J2,3 = 2 Hz,
H2β), 3.92 (dq, J4,5 = 9 Hz, J5,6 = 6 Hz, H5α), 4.61 (d, J1,2 = 1
Hz, H1β), 5.16 (dd, J1,2 = 1.5 Hz, J1,OH = 3 Hz, H1α); 13C NMR
(CDCl3, 75 MHz) δ 17.9 (C6β), 18.0 (C6α), 68.2 (C5α), 71.5
(C5β), 75.0 (C3β), 76.3 (C2β), 79.3 (C2α), 79.8 (C4β), 80.4
(C4α), 82.9 (C3α), 93.1 (C1α), 93.3 (C1β); 71.1, 116.6, 135.0 (al-
lyl-α); 71.6, 117.0, 134.6 (allyl-β); 72.9, 75.3 (benzyl-α), 74.8,
75.4 (benzyl-β); MS (FAB) m/z 407.1834 (M+Na)+. Calcd for
C23H28O5Na: 407.18344.
Allyl 3-O-Trityl-α-L-rhamnopyanoside (37). A mixture of
35 (monohydrate, 2.0 g, 11 mmol), allyl alcohol (10 mL, 15
mmol), and MeSO3H (33 µL, 0.51 mmol) was stirred at 95 °C for
3 h. After the addition of NaHCO3 (0.13 g, 1.6 mmol), the mix-
ture was evaporated to dryness and chromatographed with the CM
system (10:1) to give an anomeric mixture of the pyranosides.
This was chromatographed with the EM system to give allyl α-L-
rhamnopyranoside (36) (1.83 g, 81%); [α]D25 −69° (c 1.0, CHCl3)
(Ref. 25, [α]D20 −49° (c 1.0, CHCl3)); 1H NMR (D2O, 300 MHz) δ
1.35 (d, J5,6 = 6 Hz, H6), 2.48 (br, OH), 3.32 (t, J3,4 = J4,5 = 9 Hz,
H4), 3.33 (s, Me), 3.67 (dq, J4,5 = 9 Hz, J5,6 = 6 Hz, H5), 3.73
(dd, J1,2 = 1.5 Hz, J2,3 = 4 Hz, H2), 3.94 (dd, J2,3 = 4 Hz, J3,4 = 9
Hz, H3), 4.72 (d, J1,2 = 1.5 Hz, H1); 13C NMR (CDCl3, 75 MHz)
δ 18.0 (C6), 54.7 (Me), 67.0 (C5), 71.6 (C3), 78.6 (C2), 82.2 (C4),
97.9 (C1).
Found: C, 70.39; H, 7.52%. Calcd for C21H26O5: C, 70.37; H,
7.31%.
1
The NMR data of the acetate of 24 was as follows: H NMR
(CDCl3, 300 MHz) δ 1.35 (d, J5,6 = 6 Hz, H6), 1.96 (s, Ac), 3.34
(s, Me), 3.63 (t, J3,4 = J4,5 = 9 Hz, H4), 3.77 (dq, J4,5 = 9 Hz, J5,6
= 6 Hz, H5), 3.86 (dd, J1,2 = 2 Hz, J2,3 = 3.5 Hz, H2), 4.65 (d, J1,2
= 2 Hz, H1), 5.19 (dd, J2,3 = 3.5 Hz, J3,4 = 9 Hz, H3); 13C NMR
(CDCl3, 75 MHz) δ 18.0 (C6), 54.7 (Me), 67.6 (C5), 73.8 (C3),
76.2 (C2), 79.1 (C4). 98.8 (C1), 21.0, 170.0 (Ac).
Mthyl
3-O-Allyl-2,4-di-O-benzyl-α-L-rhamnopyanoside
(33). A mixture of 24 (1.95 g, 5.4 mmol), allyl bromide (20
mL), and NaH (ca. 60% dispersion in oil, 0.65 g, 16.3 mmol) was
stirred at 80 °C for 2 h. Evaporation and chromatography using
the TK system (20:1) 33 (1.798 g, 83%); [α]D22 −39° (c 0.9,
CHCl3) (Ref. 24, [α]D23 −40.64° (c 1.2, CHCl3)); 1H NMR (CDCl3,
300 MHz) δ 1.34 (d, J5,6 = 6 Hz, H6), 3.30 (s, Me), 3.58 (t, J3,4
=
J4,5 = 9 Hz, H4), 3.66 (dq, J4,5 = 9 Hz, J5,6 = 6 Hz, H5), 3.73 (dd,
J2,3 = 3 Hz, J3,4 = 9 Hz, H3), 3.76 (dd, J1,2 = 1.5 Hz, J2,3 = 3 Hz,
H2), 4.65 (d, J1,2 = 1.5 Hz, H1), 5.95 (m, allyl); 13C NMR
(CDCl3, 75 MHz) δ 18.0 (C6), 54.5 (Me), 67.8 (C5), 74.7 (C2),
79.8 (C3), 80.4 (C4). 99.1 (C1); 71.0, 116.5, 135.0 (allyl).
Found: C, 72.37; H, 7.79%. Calcd for C24H30O5: C, 72.34; H,
7.59%.
This was done alternatively as follows: A mixture of 30 (1.54 g,
# The previous value9 was corrected.

1688 Bull. Chem. Soc. Jpn., 74, No. 9 (2001)
Synthesis of β-D-Ribf-(1→3)-α-L-Rhap-(1→3)-
1.28 (d, J5,6 = 6 Hz, H6), 3.43 (t, J3,4 = J4,5 = 9.5 Hz, H4), 3.69
give benzyl α-L-rhamnofuranoside (39) (0.168 g, 6%), and then an
anomeric mixture of the pyranosides. This was chromatographed
with the EM system (4:1) affording benzyl α-L-rhamnopyrano-
side (38) (1.95 g, 70%) as the main product.
(dq, J4,5 = 9.5 Hz, J5,6 = 6 Hz, H5), 3.74 (dd, J2,3 = 3 Hz, J3,4
=
9.5 Hz, H3), 3.93 (dd, J1,2 = 1.5 Hz, J2,3 = 3 Hz, H2), 4.83 (d, J1,2
= 1.5 Hz, H1), 5.96 (m, allyl); 13C NMR (D2O, 75 MHz) δ 20.1
(C6), 72.1 (C5), 73.6 (C2), 73.8 (C3), 75.5 (C4), 102.5 (C1, JC1,H1
= 169.5 Hz); 71.7, 121.9, 136.8 (allyl).
Found: C, 51.75; H, 8.08%. Calcd for C9H16O5•0.25H2O: C,
51.79; H, 7.97%.
38: [α]D20 −59° (c 1.1, H2O) (Ref. 27, [α]D20 −63° (c 1, H2O),
[α]D −87° (c 0.5, MeOH)); 1H NMR (D2O, 300 MHz) δ 1.26 (d,
J5,6 = 6 Hz, H6), 3.44 (t, J3,4 = J4,5 = 9.5 Hz, H4), 3.71 (dq, J4,5 =
9.5 Hz, J5,6 = 6 Hz, H5), 3.74 (dd, J2,3 = 3 Hz, J3,4 = 9.5 Hz, H3),
3.93 (dd, J1,2 = 2 Hz, J2,3 = 3 Hz, H2), 4.89 (d, J1,2 = 2 Hz, H1);
13C NMR (D2O, 75 MHz) δ 20.0 (C6), 72.2 (C5), 73.7 (C2), 73.8
(C3), 75.5 (C4), 102.9 (C1, JC1,H1 = 169.5 Hz), 73.1 (benzyl).
Found: C, 60.50; H, 7.25%. Calcd for C13H18O5•0.25H2O: C,
60.33; H, 7.21%.
A mixture of 36 (1.573 g, 8.7 mmol), trityl chloride (4.274 g,
15 mmol), and pyridine (4.3 mL) was stirred at 60 °C for 16 h.
After the addition of Et3N (4.3 mL),14 the mixture was evaporated
to dryness and chromatographed with the TK system (4:1) to give
37 (2.83 g, 82%); [α]D21 −46° (c 5, CHCl3); 1H NMR (CDCl3, 300
MHz) δ 1.27 (d, J5,6 = 6 Hz, H6), 1.65 (d, J4,OH = 3 Hz, OH-4),
39: [α]D20 −83° (c 1.6, MeOH); H NMR (D2O, 300 MHz) δ
1
2.29 (d, J2,OH = 3 Hz, OH-2), 3.00 (dt, J1,2 = 2 Hz, J2,3 = J2,OH
=
1.35 (d, J5,6 = 6 Hz, H6), 3.86 (t, J3,4 = J4,5 = 5 Hz, H4), 4.11 (dd,
J1,2 = 1.5 Hz, J2,3 = 5 Hz, H2), 4.15 (dq, J4,5 = 5 Hz, J5,6 = 6 Hz,
H5), 4.48 (t, J2,3 = J3,4 = 5 Hz, H3), 5.06 (d, J1,2 = 1.5 Hz, H1);
13C NMR (D2O, 75 MHz) δ 18.9 (C6), 68.0 (C5), 71.9 (C3), 76.5
(C2), 81.5 (C4), 106.7 (C1, JC1,H1 = 172.1 Hz), 69.6 (benzyl).
Found: C, 61.23; H, 7.31%. Calcd for C13H18O5: C, 61.40; H,
7.14%.
3 Hz, H2), 3.48 (dq, J4,5 = 9 Hz, J5,6 = 6 Hz, H5), 3.73 (dt, J4,OH
= 3 Hz, J3,4 = J4,5 = 9 Hz, H4), 3.83 (dd, J2,3 = 3 Hz, J3,4 = 9 Hz,
H3), 4.57 (d, J1,2 = 2 Hz, H1), 5.74 (m, allyl); 13C NMR (CDCl3,
75 MHz) δ 17.9 (C6), 68.3 (C5), 69.7 (C2), 72.0 (C4), 74.7 (C3),
98.6 (C1); 67.4, 116.1, 133 (allyl).
Found: C, 75.35; H, 7.09%. Calcd for C28H30O5: C, 75.31; H,
6.77%.
A mixture of 38 (665.0 mg, 2.62 mmol), trityl chloride (1.44 g,
5.2 mmol), and pyridine (1.44 mL) was stirred at 60 °C for 18 h.
After the addition of Et3N (1.4 mL),14 the mixture was evaporated
to dryness and chromatographed with the TK system (10:1) to
give 40 (0.98 g, 75%), [α]D21 −27° (c 1.0, CHCl3); 1H NMR
(CDCl3, 300 MHz) δ 1.30 (d, J5,6 = 6 Hz, H6), 2.88 (br, OH), 3.26
(br, OH), 3.46 (t, J3,4 = J4,5 = 9.5 Hz, H4), 3.69 (dq, J4,5 = 9.5 Hz,
J5,6 = 6 Hz, H5), 3.79 (dd, J2,3 = 3 Hz, J3,4 = 9.5 Hz, H3), 3.94
1
The NMR data of the acetate of 37 was as follows: H NMR
(CDCl3, 300 MHz) δ 1.12 (d, J5,6 = 6 Hz, H6); 1.87, 2.23 (s, Ac);
3.50 (dq, J4,5 = 9.5 Hz, J5,6 = 6 Hz, H5), 3.90 (dd, J2,3 = 3 Hz, J3,4
= 9.5 Hz, H3), 4.25 (dd, J1,2 = 2 Hz, J2,3 = 3 Hz, H2), 4.61 (d, J1,2
= 2 Hz, H1), 5.30 (t, J3,4 = J4,5 = 9.5 Hz, H4), 5.71 (m, allyl); 13
C
NMR (CDCl3, 75 MHz) δ 17.7 (C6), 67.0 (C5), 69.7 (C3), 72.1
(C2), 72.4 (C4), 96.2 (C1), 87.5 (trityl); 21.2, 21.3, 170.3 (2C,
Ac); 67.8, 116.2, 133.5 (allyl).
(dd, J1,2 = 1 Hz, J2,3 = 3 Hz, H2), 4.84 (d, J1,2 = 1 Hz, H1); 13
C
Allyl 2,4-Di-O-benzyl-α-L-rhamnopyranosides (25). To a
mixture of 37 (3.263 g, 7.3 mmol), PhCH2Br (6.0 mL, 50 mmol),
and DMF (32 mL), NaH (60% in oil, 1.88 g, 47 mmol) was added
at 0 °C. The mixture was stirred for 15 min and then for 20 °C for
1 h, followed by quenching with MeOH (4 mL) and chromatogra-
phy with the TK system (20:1), as described for 24,to give chro-
matographically pure benzyl ether. This was treated with
CF3CO2H (5.0mL, 67 mmol) in CHCl3 (74 mL) containing MeOH
(10 mL) at room temperature for 2 h. Evaporation at 25 °C and
chromatography with TK system (10:1) afforded 25 (1.917 g,
68%), [α]D22 −2° (c 0.5, CH2Cl2) (Ref. 26, [α]D25 +0.5° (c 1.10,
CH2Cl2)); 1H NMR (CDCl3, 300 MHz) δ 1.34 (d, J5,6 = 6 Hz, H6),
2.31 (d, J3,OH = 9 Hz, OH-3), 3.33 (t, J3,4 = J4,5 = 9 Hz, H4), 3.71
NMR (CDCl3, 75 MHz) δ 17.5 (C6),68.1 (C5), 69.2 (benzyl), 71.1
(C2), 71.9 (C3), 73.4 (C4), 98.9 (C1, JC1,H1 = 167.7 Hz), 82.1 (tri-
tyl).
Found: C, 76.81; H, 6.75%. Calcd for C32H32O5: C, 77.40; H,
6.50%.
1
The NMR data of the acetate of 40 was as follows: H NMR
(CDCl3, 300 MHz) δ 1.12 (d, J5,6 = 6 Hz, H6); 1.85, 2.25 (s, Ac),
3.51 (dq, J4,5 = 9.5 Hz, J5,6 = 6 Hz, H5), 3.90 (dd, J2,3 = 3 Hz, J3,4
= 9.5 Hz, H3), 4.33 (dd, J1,2 = 2 Hz, J2,3 = 3 Hz, H2), 4.72 (d, J1,2
= 2 Hz, H1), 5.33 (t, J3,4 = J4,5 = 9.5 Hz, H4), 4.28, 4.51 (d, Jgem
= 12 Hz, benzyl); 13C NMR (CDCl3, 75 MHz) δ 17.7 (C6), 67.1
(C5), 69.7 (C3), 72.1 (C2), 72.4 (C4), 96.5 (C1), 87.6 (trityl);
21.2, 21.3, 170.3 (2C) (Ac).
(dq, J4,5 = 9 Hz, J5,6 = 6 Hz, H5), 3.76 (dd, J1,2 = 1.5 Hz, J2,3
=
Benzyl 2,4-Di-O-benzyl-α-L-rhamnopyranosides (26).
To
3.5 Hz, H2), 3.98 (dt, J2,3 = 3.5 Hz, J3,4 = J3,OH= 9Hz, H3), 4.87
(d, J1,2 = 1.5 Hz, H1), 5.86 (m, allyl); 13C NMR (CDCl3, 75 MHz)
δ 18.0 (C6), 67.2 (C5), 71.7 (C3), 78.7 (C2), 82.3 (C4), 96.1 (C1);
67.7, 117.2, 133.7 (allyl).
a mixture of 40 (548 mg, 1.1 mmol), PhCH2Br (1.0 mL, 8.4
mmol), and DMF (4.8 mL), NaH (60% in oil, 290 mg, 7.3 mmol)
was added at 0 °C and the mixture was stirred for 15 min. The
mixture was then stirred for 20 °C for 1 h, followed by quenching
with MeOH (1 mL). Chromatography with the TK system (30:1),
as described for 24, gave chromatographically purebenzyl ether
(1.17 g). This was treated with CF3CO2H (1.0 mL, 13.5 mmol) in
CH2Cl2 (15 mL) containing MeOH (2 mL) at room temp for 2 h.
Evaporation at 25 °C and chromatography with the TK system
(10:1) afforded 26 (411 mg, 86%), [α]D24 −31° (c 2.1, CHCl3)
Found: C, 71.46; H, 7.42%. Calcd for C23H28O5: C, 71.85; H,
7.34%.
1
The NMR data of the acetate of 25 was as follows: H NMR
(CDCl3, 300 MHz) δ 1.34 (d, J5,6 = 6 Hz, H6), 1.97 (s, Ac), 3.64
(t, J3,4 = J4,5 = 9 Hz, H4), 3.81 (dq, J4,5 = 9 Hz, J5,6 = 6 Hz, H5),
3.88 (dd, J1,2 = 2 Hz, J2,3 = 3 Hz, H2), 4.80 (d, J1,2 = 2 Hz, H1),
5.23 (dd, J2,3 = 3 Hz, J3,4 = 9 Hz, H3), 5.86 (m, allyl); 13C NMR
(CDCl3, 75 MHz) δ 18.0 (C6), 67.8 (C5), 73.8 (C3), 76.3 (C2),
79.2 (C4), 96.8 (C1); 67.9, 117.3, 133.7 (allyl); 21.1, 170.1 (Ac).
1
(Ref. 28, [α]D −38.5° (CHCl3)); H NMR (CDCl3, 300 MHz) δ
1.35 (d, J5,6 = 6 Hz, H6), 2.37 (s, OH-3), 3.37 (t, J3,4 = J4,5 = 9
Hz, H4), 3.76 (dq, J4,5 = 9 Hz, J5,6 = 6 Hz, H5), 3.78 (dd, J1,2
=
Benzyl 3-O-Trityl-α-L-rhamnopyanoside (40).
A
mixture
1.5 Hz, J2,3 = 4 Hz, H2), 4.02 (dd, J2,3 = 4 Hz, J3,4 = 9 Hz, H3),
4.92 (d, J1,2 = 1.5 Hz, H1); 13C NMR (CDCl3, 75 MHz) δ 18.0
(C6), 67.5 (C5), 71.7 (C3), 78.7 (C2), 82.3 (C4), 96.3 (C1, JC1,H1
= 166.0 Hz).
of 35 (monohydrate, 2.00 g, 11 mmol), benzyl alcohol (4.0 mL, 39
mmol), and MeSO3H (0.40 mL, 62 mmol) was stirred for 40 min
at 75 °C. After the addition of CHCl3 (5 mL) and Et3N (1.6 mL),
the mixture was chromatographed with the CM system (10:1) to
Found: C, 74.50; H, 7.04%. Calcd for C27H30O5: C, 74.63; H,

M. Hirooka et al.
Bull. Chem. Soc. Jpn., 74, No. 9 (2001) 1689
Ⅱ
Ⅰ
6.96%.
Hz, J4,5b = 4 Hz, H4 ), 4.77 (d, J1,2 = 2 Hz, H1 ), 5.28 (d, J1,2 = 4
1
Ⅱ
The NMR data of the acetate of 26 was as follows: H NMR
(CDCl3, 300 MHz) δ 1.35 (d, J5,6 = 6 Hz, H6), 1.98 (s, Ac), 3.66
(t, J3,4 = J4,5 = 9.5 Hz, H4), 3.85 (dq, J4,5 = 9.5 Hz, J5,6 = 6 Hz,
H5), 3.91 (dd, J1,2 = 2 Hz, J2,3 = 3.5 Hz, H2), 4.86 (d, J1,2 = 2 Hz,
H1), 5.27 (dd, J2,3 = 3.5 Hz, J3,4 = 9.5 Hz, H3), 13C NMR (CDCl3,
75 MHz) δ 18.0 (C6), 68.0 (C5), 73.8 (C3), 76.3 (C2), 79.3 (C4),
97.0 (C1); 21.0, 170.1 (Ac).
Methyl O-(2,3,5-Tri-O-benzyl-α- and β-D-ribofuranosyl)-
(1→3)-2,4-di-O-benzyl-α-L-rhamnopyranosides (16a and 16b)
(Table 2, Run 1). To a mixture of 1 (39.4 mg, 0.094 mmol), 24
(33.6 mg, 0.094 mol), CoBr2 (22.5 mg, 0.103 mmol), Bu4NBr
(33.2 mg, 0.103 mmol), MS4A (94 mg), and CH2Cl2 (0.94 mL),
TMSBr (13.6 µL, 0.103 mmol) was added under stirring at room
temp (ca. 25 °C). The mixture was then stirred well under anhy-
drous conditions for 24 h. After the addition of PhMe (2 mL) and
NaHCO3 (8.7 mg), the mixture was stirred for 15 min. The mix-
ture was transferred onto a column of silica gel, which was eluted
with the TK system (10:1) to give 16b (30.1 mg, 42%) and 16a
(8.0 mg, 11%).
Hz, H1 ), 5.82 (m, allyl); 13C NMR (CDCl3, 75 MHz) δ 17.9
Ⅰ
Ⅰ
Ⅱ
Ⅰ
Ⅱ
Ⅰ
(C6 ), 68.1 (C5 ), 70.0 (C5 ), 74.9 (C2 ), 75.4 (C3 ), 76.7 (C3 ),
Ⅱ
Ⅰ
Ⅱ
Ⅰ
78.3 (C2 ), 79.5 (C4 ), 82.0 (C4 ), 97.5 (C1 , JC1,H1 = 170.0 Hz),
Ⅱ
99.3 (C1 , JC1,H1 = 172.4 Hz), 67.7, 117.0, 134.0 (allyl).
17b; [α]D20 −9° (c 0.9, CHCl3); 1H NMR (CDCl3, 300 MHz) δ
Ⅰ
1.30 (d, J5,6 = 6 Hz, H6 ), 3.45 (dd, J4,5a = 5 Hz, J5a,5b = 10 Hz,
Ⅱ
Ⅰ
H5a ), 3.55 (t, J3,4 = J4,5 = 9.5 Hz, H4 ), 3.61 (dd, J4,5b = 3.5 Hz,
Ⅱ
Ⅰ
J5a,5b = 10 Hz, H5b ), 3.73 (dq, J4,5 = 9.5 Hz, J5,6 = 6 Hz, H5 ),
Ⅰ
3.82 (dd, J1,2 = 1.5 Hz, J2,3 = 3 Hz, H2 ), 3.93 (dd, J1,2 = 1 Hz,
J2,3 = 4 Hz, H2 ), 4.00 (dd, J2,3 = 4 Hz, J3,4 = 7 Hz, H3 ), 4.10
(dd, J2,3 = 3 Hz, J3,4 = 9.5 Hz, H3 ), 4.34 (ddd, J3,4 = 7 Hz, J4,5a
Ⅱ
Ⅱ
Ⅰ
=
Ⅱ
Ⅰ
5 Hz, J4,5b = 3.5 Hz, H4 ), 4.70 (d, J1,2 = 1.5 Hz, H1 ), 5.41 (d,
J1,2 = 1 Hz, H1 ), 5.87 (m, allyl); 13C NMR (CDCl3, 75 MHz) δ
Ⅱ
Ⅰ
Ⅰ
Ⅱ
Ⅱ
Ⅰ
17.9 (C6 ), 68.1 (C5 ), 71.1 (C5 ), 77.7 (C3 ), 78.4 (C3 ), 78.6
Ⅰ
Ⅱ
Ⅱ
Ⅰ
Ⅰ
(C2 ), 80.08 (C2 ), 80.11 (C4 ), 80.7 (C4 ), 97.3 (C1 ), 106.7
(C1 , JC1,H1 = 173.4 Hz), 67.7, 117.1, 133.9 (allyl).
Found: 17a C, 74.54; H, 6.97%. 17b C, 74.86; H, 7.08%. Cal-
cd for C49H54O9: C, 74.78; H, 6.92%.
A similar ribofuranosylation using (CH2Cl)2 as a solvent gave
17a (19%) and 17b (40%) (Run 4).
Ⅱ
1
16a; [α]D +5° (c 1.1, CHCl3); H NMR (CDCl3, 300 MHz) δ
1.30 (d, J5,6 = 6 Hz, H6 ), 3.29 (s, Me), 3.40 (dd, J4,5a = 4 Hz,
Ⅰ
Methyl O-(2-O-Allyl-3,5-di-O-benzyl-α- and β-D-ribofura-
nosyl)-(1→3)-2,4-di-O-benzyl-α-L-rhamnopyranosides (18a
and 18b) (Run 5). Acceptor 24 (89.8 mg, 0.25 mmol) was con-
densed with 21 (90.4 mg, 0.24 mol) in the presence of TMSBr
(34.9 µL, 0.27 mmol), CoBr2 (58.8 mg, 0.27 mmol), Bu4NBr
(86.8 mg, 0.27 mmol), and MS4A (246 mg) in CH2Cl2 (2.5 mL) to
afford 18b (the faster-moving by the TK system (10:1), 69.1 mg,
Ⅱ
J5a,5b = 10.5 Hz, H5a ), 3.47 (dd, J4,5b = 4 Hz, J5a,5b = 10.5 Hz,
Ⅱ
Ⅰ
H5b ), 3.62 (t, J3,4 = J4,5 = 9 Hz, H4 ), 3.68 (dq, J4,5 = 9 Hz, J5,6
Ⅰ
Ⅰ
= 6 Hz, H5 ), 3.86 (dd, J1,2 = 2 Hz, J2,3 = 3 Hz, H2 ), 3.88 (dd,
J1,2 = 4 Hz, J2,3 = 6.5 Hz, H2 ), 3.93 (dd, J2,3 = 6.5 Hz, J3,4 = 3.5
Hz, H3 ), 4.20 (dd, J2,3 = 3 Hz, J3,4 = 9 Hz, H3 ), 4.32 (dt, J3,4
Ⅱ
Ⅱ
Ⅰ
=
Ⅱ
Ⅰ
3.5 Hz, J4,5a = J4,5b = 4 Hz, H4 ), 4.63 (d, J1,2 = 2 Hz, H1 ), 5.27
(d, J1,2 = 4 Hz, H1 ); 13C NMR (CDCl3, 75 MHz) δ 18.0 (C6 ),
40%); [α]D23 −3° (c 0.5, CHCl3); H NMR (CDCl3, 300 MHz) δ
1.28 (d, J5,6 = 6 Hz, H6 ), 3.31 (s, Me), 3.42 (dd, J4,5a = 5.5 Hz,
J5a,5b = 10.5 Hz, H5a ), 3.52 (t, J3,4 = J4,5 = 9.5 Hz, H4 ), 3.58
Ⅱ
Ⅰ
1
Ⅰ
Ⅱ
Ⅰ
Ⅱ
Ⅰ
54.6 (Me), 68.0 (C5 ), 70.1 (C5 ), 75.0 (C2 ), 75.5 (C3 ), 76.7
Ⅰ
Ⅱ
Ⅰ
Ⅱ
Ⅱ
Ⅱ
Ⅰ
(C3 ), 78.4 (C2 ), 79.4 (C4 ), 82.0 (C4 ), 99.2 (C1 , JC1,H1 = 162.7
Ⅰ
Ⅱ
Hz), 99.4 (C1 , JC1,H1 = 168.8 Hz).
(dd, J4,5b = 3.5 Hz, J5a,5b = 10.5 Hz, H5b ), 3.66 (dq, J4,5 = 9.5
16b; [α]D19 +2° (c 0.9, CHCl3); 1H NMR (CDCl3, 300 MHz) δ
Hz, J5,6 = 6 Hz, H5 ), 3.77 (dd, J1,2 = 1.5 Hz, J2,3 = 3 Hz, H2 ),
Ⅰ
Ⅰ
Ⅰ
Ⅱ
1.30 (d, J5,6= 6 Hz, H6 ), 3.33 (s, Me), 3.45 (dd, J4,5a = 5.5 Hz,
J5a,5b = 10.5 Hz, H5a ), 3.55 (t, J3,4 = J4,5 = 9.5 Hz, H4 ), 3.61
(dd, J4,5b = 3.5 Hz, J5a,5b = 10.5 Hz, H5b ), 3.69 (dq, J4,5 = 9.5
Hz, J5,6 = 6 Hz, H5 ), 3.79 (dd, J1,2 = 1.5 Hz, J2,3 = 3 Hz, H2 ),
3.92 (dd, J1,2 = 1 Hz, J2,3 = 4.5 Hz, H2 ), 4.01 (dd, J2,3 = 4.5 Hz,
J3,4 = 7 Hz, H3 ), 4.07 (dd, J2,3 = 3 Hz, J3,4 = 9.5 Hz, H3 ), 4.33
3.83 (dd, J1,2 = 1 Hz, J2,3 = 4.5 Hz, H2 ), 3.98 (dd, J2,3 = 4.5 Hz,
J3,4 = 7.5 Hz, H3 ), 4.03 (dd, J2,3 = 3 Hz, J3,4 = 9.5 Hz, H3 ), 4.26
Ⅱ
Ⅰ
Ⅱ
Ⅰ
Ⅱ
Ⅱ
(ddd, J3,4 = 7.5 Hz, J4,5a = 5.5 Hz, J4,5b = 3.5 Hz, H4 ),4.52 (d,
J1,2 = 1.5 Hz, H1 ), 5.31 (d, J1,2 = 1 Hz, H1 ), 5.74 (m, allyl); 13
C
Ⅰ
Ⅰ
Ⅰ
Ⅱ
Ⅱ
Ⅰ
Ⅰ
Ⅱ
NMR (CDCl3, 75 MHz) δ 17.9 (C6 ), 67.9 (C5 ), 70.9 (C5 ), 77.6
Ⅱ Ⅰ Ⅰ Ⅱ Ⅱ Ⅰ
Ⅱ
Ⅰ
(C3 ), 78.3 (C3 ), 78.5 (C2 ), 80.0 (2C, C2 and C4 ), 80.6 (C4 ),
Ⅱ
Ⅰ
Ⅱ
(ddd, J3,4 = 7 Hz, J4,5a = 5.5 Hz, J4,5b = 3.5 Hz, H4 ), 4.55 (d, J1,2
99.2 (C1 ), 106.8 (C1 ); 54.6 (Me), 71.1, 117.2, 134.3 (allyl); MS
= 1.5 Hz, H1 ), 5.41 (d, J1,2 = 1 Hz, H1 ); 13C NMR (CDCl3, 75
(FAB) m/z 733.3353 (M+Na)+.
Calcd for C43H50O9Na:
Ⅰ
Ⅱ
Ⅰ
Ⅰ
Ⅱ
Ⅱ
Ⅰ
MHz) δ 18.0 (C6 ), 68.0 (C5 ), 71.0 (C5 ), 77.8 (C3 ), 78.3 (C3 ),
78.6 (C2 ), 80.2 (2C, C2 and C4 ), 80.7 (C4 ), 99.3 (C1 , JC1,H1
166.0 Hz), 106.7 (C1 , JC1,H1 = 172.5 Hz).
A similar reaction (Run 2) using (CH2Cl)2 as the solvent gave
16a (13%) and 16b (43%).
733.33522.
Further elution afforded 18a (64.3 mg, 37%): [α]D24 +9° (c 0.8,
Ⅰ
Ⅱ
Ⅱ
Ⅰ
Ⅰ
=
CHCl3); 1H NMR (CDCl3, 300 MHz) δ 1.31 (d, J5,6 = 6 Hz, H6 ),
Ⅱ
Ⅰ
Ⅱ
3.30 (s, Me), 3.41 (dd, J4,.5a = 3.5 Hz, J5a,5b = 10.5 Hz, H5a ),
3.48 (dd, J4,5b = 4 Hz, J5a,5b = 10.5 Hz, H5b ), 3.62 (t, J3,4 = J4,5
= 9 Hz, H4 ), 3.69 (dq J4,5 = 9 Hz, J5,6 = 6 Hz, H5 ), 3.84 (dd, J1,2
= 4 Hz, J2,3 = 6.5 Hz, H2 ), 3.85 (dd, J1,2 = 2 Hz, J2,3 = 3 Hz,
Ⅱ
Ⅰ
Ⅰ
Found: 16a, C, 73.94; H, 6.99%. 16b, C, 73.92; H, 6.96%.
Calcd for C47H52O9: C, 74.19; H, 6.89%.
Ⅱ
Ⅰ
Ⅱ
Allyl O-(2,3,5-Tri-O-benzyl-α- and β-D-ribofuranosyl)-
(1→3)-2,4-di-O-benzyl-α-L-rhamnopyranosides (17a and 17b)
(Run 3). Condensation of 1 (43.5 mg, 0.103 mmol) and 25 (39.8
mg, 0.103 mol) in the presence of TMSBr (15.0 µL, 0.114 mmol),
CoBr2 (24.9 mg, 0.114 mmol), Bu4NBr (36.7 mg, 0.114 mmol),
and MS4A (103.4 mg) in CH2Cl2 (1.03 mL) gave 17b (the faster-
moving (TK 10:1), 25.8 mg, 32%) and 17a (11.3 mg, 14%).
H2 ), 3.93 (dd, J2,3 = 6.5 Hz, J3,4 = 3.5 Hz, H3 ), 4.19 (dd, J2,3 =
Ⅰ
Ⅱ
Ⅰ
3 Hz, J3,4 = 9 Hz, H3 ), 4.31 (m, H4 ), 4.66 (d, J1,2 = 2 Hz, H1 ),
5.24 (d, J1,2 = 4 Hz, H1 ), 5.89 (m, allyl); 13C NMR (CDCl3, 75
Ⅱ
Ⅰ
Ⅰ
Ⅱ
Ⅰ
Ⅱ
MHz) δ 18.0 (C6 ), 68.0 (C5 ), 70.1 (C5 ), 74.6 (C2 ), 75.4 (C3 ),
Ⅰ
Ⅱ
Ⅰ
Ⅱ
Ⅱ
76.7 (C3 ), 78.6 (C2 ), 79.4 (C4 ), 82.0 (C4 ), 99.2 (C1 ), 99.4
Ⅰ
(C1 ); 54.5 (Me); 71.7, 117.7, 134.7 (allyl); MS (FAB) m/z
733.3353 (M+Na)+. Calcd for C43H50O9Na: 733.33522.
In the case of Run 6 using (CH2Cl)2, 18a (26%) and 18b (31%)
were obtained.
17a;[α]D21 +5° (c 0.8, CHCl3); H NMR (CDCl3, 300 MHz) δ
1.29 (d, J5,6 = 6 Hz, H6 ), 3.41 (dd, J4,5a = 3.5 Hz, J5a,5b = 10.5
Hz, H5a ), 3.47 (dd, J4,5b = 4 Hz, J5a,5b = 10.5 Hz, H5b ), 3.63 (t,
J3,4 = J4,5 = 9 Hz, H4 ), 3.73 (dq, J4,5 = 9 Hz, J5,6 = 6 Hz, H5 ),
3.877 (dd, J1,2 = 2 Hz, J2,3 = 3 Hz, H2 ), 3.878 (dd, J1,2 = 4 Hz,
J2,3 = 6.5 Hz, H2 ), 3.94 (dd, J2,3 = 6.5 Hz, J3,4 = 3.5 Hz, H3 ),
4.23 (dd, J2,3 = 3 Hz, J3,4 = 9 Hz, H3 ), 4.33 (dt, J3,4 = J4,5a = 3.5
1
Ⅰ
Ⅱ
Ⅱ
Methyl O-(3-O-Allyl-2,4-di-O-benzyl-α-L-rhamnopyranos-
yl)-(1→3)-2,4-di-O-benzyl-α-L-rhamnopyranosides (19) (Run
7). Acceptor 24 (208.0 mg, 0.58 mmol) was condensed with 22
(223.1 mg, 0.58 mol) in the presence of TMSBr (84.2 µL, 0.64
mmol), CoBr2 (140.0 mg, 0.64 mmol), Bu4NBr (206.0 mg, 0.64
Ⅰ
Ⅰ
Ⅰ
Ⅱ
Ⅱ
Ⅰ

1690 Bull. Chem. Soc. Jpn., 74, No. 9 (2001)
Synthesis of β-D-Ribf-(1→3)-α-L-Rhap-(1→3)-
Ⅰ
mmol), and MS4A (342.5 mg) in (CH2Cl)2 (3.5 mL), followed by
chromatography with the TK system (10:1) to afford 19 (269.1
mg, 50%); [α]D20 −22° (c 1.3, CHCl3) (Ref. 29, [α]D −39° (c 0.3,
(dd, J1,2 = 1 Hz, J2,3 = 3 Hz, H2 ), 3.709 (dq, J4,5 = 9 Hz, J5,6 = 6
Ⅰ
Ⅱ
Hz, H5 ), 3.79 (dq, J4,5 = 9.5 Hz, J5,6 = 6 Hz, H5 ), 3.99 (dt, J2,3
Ⅱ
= 4 Hz, J3,4 = J3,OH = 9.5 Hz, H3 ), 4.10 (dd, J2,3 = 3 Hz, J3,4 = 9
1
Ⅰ
Ⅱ
Ⅰ
CHCl3)); H NMR (CDCl3, 300 MHz) δ 1.278 (d, J5,6 = 6 Hz,
Hz, H3 ), 4.66 (d, J1,2 = 1 Hz, H1 ), 5.19 (d, J1,2 = 1 Hz, H1 ); 13
C
Ⅱ
Ⅰ
Ⅰ
Ⅱ
Ⅱ
H6 ), 1.283 (d, J5,6 = 6 Hz, H6 ), 3.30 (s, Me), 3.56 (t, J3,4 = J4,5
NMR (CDCl3, 75 MHz) δ 18.0 (C6 ), 18.1 (C6 ), 67.8 (C5 ), 68.2
Ⅰ Ⅱ Ⅰ Ⅰ Ⅱ Ⅰ
Ⅱ
Ⅱ
= 9 Hz, H4 ), 3.59 (dd, J2,3 = 3 Hz, J3,4 = 9 Hz, H3 ), 3.67 (dq,
(C5 ), 71.6 (C3 ), 77.9 (2C, C2 and C3 ), 79.2 (C2 ), 81.0 (C4 ),
Ⅱ
Ⅱ
Ⅱ
Ⅰ
J4,5 = 9 Hz, J5,6 = 9 Hz, H5 ), 3.72 (dd, J1,2 = 2 Hz, J2,3 = 3 Hz,
82.3 (C4 ), 98.80 (C1 , JC1,H1 = 168.3 Hz), 98.84 (C1 , JC1,H1 =
Ⅱ
Ⅰ
H2 ), 3.77 (dd, J1,2 = 1.5 Hz, J2,3 = 3 Hz, H2 ), 3.80 (dq, J4,5 = 9
169.0 Hz), 54.7 (Me).
Ⅰ
Ⅰ
Hz, J5,6 = 6 Hz, H5 ), 3.82 (t, J3,4 = J4,5 = 9 Hz, H4 ), 4.07 (dd,
Found: C, 71.36; H, 7.11%. Calcd for C41H48O9: C, 71.91; H,
7.06%.
Ⅰ
Ⅱ
J2,3 = 3 Hz, J3,4 = 9 Hz, H3 ), 4.63 (d, J1,2 = 2 Hz, H1 ), 5.16 (d,
J1,2 = 1.5 Hz, H1 ); 13C NMR (CDCl3, 75 MHz) δ 18.0 (C6 ), 18.1
O-(2,3,5-Tri-O-benzyl-β-D-ribofuranosyl)-(1→3)-2,4-di-O-
benzyl-L-rhamnopyranose (43). Compound 17b (36.1 mg,
0.046 mmol) was treated with PdCl2 (80.8 mg, 0.46 mmol) and
NaOAc (15.0 mg, 0.18 mmol) in aq AcOH (95%, 2.05 mL) at
room temp for 3 h, followed by purification, as described for 41,
Ⅰ
Ⅱ
Ⅰ
Ⅱ
Ⅰ
Ⅰ
Ⅰ
Ⅱ
(C6 ), 68.0 (C5 ), 68.7 (C5 ), 75.7 (C2 ), 77.8 (C3 ), 78.0 (C2 ),
Ⅰ
Ⅱ
Ⅱ
Ⅱ
79.7 (C4 ), 80.5 (C3 ), 80.9 (C4 ), 98.7 (C1 , JC1,H1 = 168.3 Hz),
99.9 (C1 , JC1,H1 = 169.1 Hz), 54.7 (Me), 71.0, 116.4, 135.1 (al-
Ⅰ
lyl).
to give 43 (24.9 mg, 73%); [α]D22 +13° (c 1.6, CHCl3); H NMR
1
Found: C, 72.36; H, 7.17%. Calcd for C44H52O9: C, 72.91; H,
7.23%.
Ⅰ
(CDCl3, 400 MHz) (50%α) δ 1.27 (d, J5,6 = 6 Hz, H6α ), 1.29 (d,
Ⅰ
Ⅰ
Methyl O-(2,3,4-Tri-O-benzyl-α- and β-L-rhamnopyranos-
yl)-(1→2)-3,5-di-O-benzyl-β-D-ribofuranoside (20a and 20b)
(Run 8). Acceptor 23 (52.7 mg, 0.153 mmol) was condensed
with 2 (66.5 mg, 0.153 mol) in the presence of TMSBr (21.9 µL,
0.17 mmol), CoBr2 (36.9 mg, 0.17 mmol), Bu4NBr (54.3 mg, 0.17
mmol), and MS4A (153 mg) in CH2Cl2 (1.5 mL) to afford 20a
(the faster-moving by TK system (10 :1), 49.5 mg, 43%) and 20b
(18.7 mg, 16%).
J5,6 = 6 Hz, H6β ), 3.35 (dq, J4,5 = 9 Hz, J5,6 = 6 Hz, H5β ), 3.45
Ⅱ
(dd, J4,5a = 4.5 Hz, J5a,5b = 10.5 Hz, H5aβ ), 3.47 (t, J3,4 = J4,5
=
Ⅰ
Ⅱ
9 Hz, H4β ), 3.50 (dd, J4,5a = 4.5 Hz, J5a,5b = 10.5 Hz, H5aα ),
Ⅰ
3.56 (t, J3,4 = J4,5 = 9.5 Hz, H4α ), 3.61 (dd, J4,5b = 3.5 Hz, J5a,5b
Ⅱ
= 10.5 Hz, H5bβ ), 3.67 (dd, J4,5b = 3 Hz, J5a,5b = 10.5 Hz,
Ⅱ
Ⅰ
H5bα ), 3.79 (dd, J2,3 = 3 Hz, J3,4 = 9 Hz, H3β ), 3.818 (dd, J2,3
Ⅰ
= 1.5 Hz, J3,4 = 3 Hz, H2α ), 3.822 (d, J1,2 = 0 Hz, J2,3 = 3 Hz,
Ⅰ
Ⅱ
H2β ), 3.87 (dd, J1,2 = 1 Hz, J2,3 = 4.5 Hz, H2α ), 3.92 (dd, J1,2
=
20a: [α]D24 −4° (c 1.4, CHCl3); H NMR (CDCl3, 300 MHz) δ
1 Hz, J2,3 = 4.5 Hz, H2β ), 3.94 (dq, J4,5 = 9.5 Hz, J5,6 = 6 Hz,
1
Ⅱ
Ⅱ
Ⅰ
Ⅱ
1.36 (d, J5,6 = 6 Hz, H6 ), 3.32 (s, Me), 3.53 (dd, J4,.5a = 5.5 Hz,
H5α ), 4.00 (dd, J2,3 = 4.5 Hz, J3,4 = 7.5 Hz, H3β ), 4.05 (dd, J2,3
Ⅰ
Ⅰ
Ⅱ
J5a,5b = 10 Hz, H5a ), 3.63 (dd, J4,5b = 4 Hz, J5a,5b = 10 Hz, H5b ),
= 4.5 Hz, J3,4 = 7.5 Hz, H3α ), 4.14 (dd, J2,3 = 3 Hz, J3,4 = 9.5
Ⅱ
Ⅰ
3.64 (t, J3,4 = J4,5 = 9 Hz, H4 ), 3.78 (dq, J4,5 = 9 Hz, J5,6 = 6 Hz,
H5 ), 3.85 (dd, J1,2 = 2 Hz, J2,3 = 3 Hz, H2 ), 3.91 (dd, J2,3 = 3
Hz, J3,4 = 9 Hz, H3 ), 4.07 (dd, J2,3 = 4 Hz, J3,4 = 7 Hz, H3 ),
4.11 (d, J1,2 = 0 Hz, J2,3 = 4 Hz, H2 ), 4.25 (ddd, J3,4 = 7 Hz, J4,5a
Hz, H3a ), 4.32 (ddd, J3,4 = 7.5 Hz, J4,5a = 4.5 Hz, J4,5b = 3 Hz,
Ⅱ
Ⅱ
Ⅱ
H4α ), 4.33 (ddd, J3,4 = 7.5 Hz, J4,5a = 4.5 Hz, J4,5b = 3.5 Hz,
Ⅱ
Ⅰ
Ⅱ
Ⅰ
Ⅰ
H4β ), 4.66 (s, H1β ), 5.05 (d, J1,2 = 1.5 Hz, H1α ), 5.42 (d, J1,2 =
Ⅱ Ⅱ
1 Hz, H1α and H1β ); 13C NMR (CDCl3, 100 MHz) δ 17.8
Ⅰ Ⅰ Ⅰ Ⅱ Ⅱ
Ⅰ
Ⅰ
Ⅰ
= 5.5 Hz, J4,5b = 4 Hz, H4 ), 4.85 (s, H1 ), 5.04 (d, J1,2 = 2 Hz,
(C6β ), 18.0 (C6α ), 68.2 (C5α ), 69.9 and 70.8 (C5α and C5β ),
Ⅰ Ⅱ Ⅱ Ⅰ
H1 ); 13C NMR (CDCl3, 75 MHz) δ 18.0 (C6 ), 54.9 (Me), 68.6
71.4 (C5β ), 76.7 and 77.5 (C3α and C3β ), 77.6 (C3α ), 78.6
Ⅱ Ⅰ Ⅰ Ⅱ Ⅱ
Ⅱ
Ⅱ
Ⅱ
Ⅰ
Ⅱ
Ⅰ
Ⅰ
Ⅱ
(C5 ), 71.4 (C5 ), 75.1 (C2 ), 77.1 (C2 ), 79.3 (C3 ), 79.9 (C3 ),
(C2β ), 79.8 (C2β ), 79.87 (C2α ), 79.90 (C2α ), 79.99 (C4β ),
Ⅱ Ⅰ Ⅰ Ⅰ Ⅰ
Ⅰ
Ⅱ
Ⅱ
Ⅰ
80.1 (C4 ), 80.4 (C4 ), 98.3 (C1 , JC1,H1 = 168.3 Hz), 107.6 (C1 ,
JC1,H1 = 168.3 Hz).
80.00 (C4α ), 80.2 (C3β ), 80.3 (C4β ), 80.6 (C4α ), 93.0 (C1α ),
Ⅰ Ⅱ Ⅱ
93.1 (C1β ), 106.4 and 106.6 (C1α and C1β ).
Found: C, 73.71; H, 6.95%. Calcd for C46H50O9: C, 73.97; H,
6.75%.
20b: [α]D22 +45° (c 0.8, CHCl3); 1H NMR (CDCl3, 300 MHz) δ
Ⅱ
1.40 (d, J5,6 = 6 Hz, H6 ), 3.37 (dq, J4,5a = 9 Hz, J5,6 = 6 Hz,
H5 ), 3.38 (s, Me), 3.49 (dd, J4,.5b = 5 Hz, J5a,5b = 11.5 Hz, H5a ),
3.50 (dd, J2,3 = 3 Hz, J3,4 = 9 Hz, H3 ), 3.58 (t, J3,4 = J4,5 = 9 Hz,
H4 ), 3.69 (dd, J4,5b = 4 Hz, J5a,5b = 11.5 Hz, H5b ), 3.97 (d, J1,2
= 0 Hz, J2,3 = 3 Hz, H2 ), 4.07 (ddd, J3,4 = 7.5 Hz, J4,5a = 5 Hz,
J4,5b = 4 Hz, H4 ), 4.38 (d, J1,2 = 1 Hz, J2,3 = 4.5 Hz, H2 ), 4.45
Ⅱ
Ⅰ
Methyl O-(2,3,5-Tri-O-benzyl-β-D-ribofuranosyl)-(1→3)-O-
Ⅱ
(2,4-di-O-benzyl-α-L-rhamnopyranosyl)-(1→3)-2,4-di-O-ben-
Ⅱ
Ⅰ
zyl-α-L-rhamnopyranoside (42) (Run 9).
Acceptor 41 (40.8
Ⅱ
mg, 0.060 mmol) was condensed with 1 (25.1 mg, 0.060 mol) in
the presence of TMSBr (8.7 µL, 0.066 mmol), CoBr2 (14.3 mg,
0.065 mmol), Bu4NBr (21.1 mg, 0.065 mmol), and MS4A (40.0
mg) in (CH2Cl)2 (0.5 mL), followed by chromatography with the
TK system (10:1), to afford 42 (29.4 mg, 45%); [α]D23 −13° (c 1.3,
Ⅰ
Ⅰ
Ⅰ
Ⅱ
(dd, J2,3 = 4.5 Hz, J3,4 = 7.5 Hz, H3 ), 4.60 (s, H1 ), 4.96 (d, J1,2
= 1 Hz, H1 ); 13C NMR (CDCl3, 75 MHz) δ 18.0 (C6 ), 55.1
Ⅰ
Ⅱ
Ⅰ
Ⅱ
Ⅱ
Ⅰ
Ⅰ
(Me), 71.1 (C5 ), 72.1 (C5 ), 73.9 (C2 ), 77.6 (2C, C3 and C4 ),
80.1 (C4 ), 81.2 (C2 ), 81.9 (C3 ), 99.9 (C1 , JC1,H1 = 153.9 Hz),
106.4 (C1 , JC1,H1 = 168.0 Hz).
Ⅱ
Ⅰ
Ⅱ
Ⅱ
1
CHCl3); H NMR (CDCl3, 400 MHz) δ 1.24 (d, J5,6 = 6 Hz,
H6 ),1.25 (d, J5,6 = 6 Hz, H6 ), 3.31 (s, Me), 3.37 (dd, J4,.5a = 5
Hz, J5a,5b = 10.5 Hz, H5a ), 3.49 (dd, J4,.5b = 4.5 Hz, J5a,5b = 10.5
Hz, H5b ), 3.56 (t, J3,4 = J4.5 = 9.5 Hz, H4 ), 3.57 (t, J3,4 = J4,5
9 Hz, H4 ), 3.65 (dq, J4,5 = 9 Hz, J5,6 = 6 Hz, H5 ), 3.71 (dd, J1,2
= 1.5 Hz, J2,3 = 3 Hz, H2 ), 3.81 (dq, J4,5 = 9.5 Hz, J5,6 = 6 Hz,
H5 ), 3.91 (dd, J1,2 = 1.5 Hz, J2,3= 4.5 Hz, H2 ), 3.92 (dd, J1,2
1.5 Hz, J2,3 = 3 Hz, H2 ), 4.00 (dd, J2,3 = 4.5 Hz, J3,4 = 6.5 Hz,
Ⅰ
Ⅱ
Ⅰ
Ⅲ
Found: 20a, C, 73.66; H, 7.00%. 20b, C, 73.61; H, 6.85%.
Calcd for C47H52O9: C, 74.19; H, 6.89%.
Ⅲ
Ⅱ
=
Ⅰ
Ⅰ
Methyl O-(2,4-Di-O-benzyl-α-L-rhamnopyranosyl)-(1→3)-
2,4-di-O-benzyl-α-L-rhamnopyranoside (41). A mixture of 19
(109.4 mg, 0.151 mmol), PdCl2 (87.8 mg, 0.495 mol), NaOAc
(49.2 mg, 0.600 mmol), and aq AcOH (95%, 6.6 mL) was stirred
at 60 °C for 45 min. The mixture was evaporated to dryness at 25
°C and chromatographed with the TK (5:1) system to give 41
(83.6 mg, 81%); [α]D20 −18° (c 0.3, CHCl3) (Ref. 29, [α]D −17.2°
Ⅰ
Ⅱ
Ⅲ
=
Ⅱ
Ⅲ
Ⅰ
H3 ), 4.06 (dd, J2,3 = 3, 9 Hz, H3 ), 4.17 (dd, J2,3 = 3 Hz, J3,4
=
Ⅱ
Ⅰ
9.5 Hz, H3 ), 4.66 (d, J1,2 = 1.5 Hz, H1 ), 5.11 (d, J1,2 = 1.5 Hz,
Ⅱ
Ⅲ
H1 ), 5.42 (d, J1,2 = 1.5 Hz, H1 ); 13C NMR (CDCl3, 100 MHz) δ
1
Ⅱ
Ⅰ
Ⅰ
Ⅱ
(c 1.0, CHCl3)); H NMR (CDCl3, 300 MHz) δ 1.28 (d, J5,6 = 6
17.9 (C6 ), 18.0 (C6 ), 54.6 (Me), 68.0 (C5 ), 68.6 (C5 ), 70.9
Ⅱ
Ⅰ
Ⅲ
Ⅲ
Ⅰ
Ⅰ
Ⅱ
Ⅱ
Hz, H6 ), 1.32 (d, J5,6 = 6 Hz, H6 ), 2.27 (d, J3,OH = 9.5 Hz, OH-
(C5 ), 77.3 (C3 ), 77.6 (C3 ), 77.8 (C2 ), 78.8 (C3 ), 79.2 (C2 ),
Ⅱ
Ⅱ
Ⅲ
Ⅲ
Ⅱ
Ⅰ
Ⅰ
3 ), 3.31 (t, J3,4 = J4,5 = 9.5 Hz, H4 ), 3.33 (s, Me), 3.61 (t, J3,4
J4,5 = 9 Hz, H4 ), 3.707 (dd, J1,2 = 1 Hz, J2,3 = 4 Hz, H2 ), 3.708
=
80.1 (C4 ), 80.4 (C2 ), 80.6 (C4 ), 80.8 (C4 ), 98.7 (C1 , JC1,H1 =
Ⅰ
Ⅱ
Ⅱ
Ⅲ
170 Hz), 99.8 (C1 , JC1,H1 = 170 Hz), 107.1 (C1 , JC1,H1 = 175

M. Hirooka et al.
Bull. Chem. Soc. Jpn., 74, No. 9 (2001) 1691
Hz).
the presence of TMSBr (8.1 µL, 0.061 mmol), CoBr2 (13.5 mg,
0.062 mmol), Bu4NBr (19.8 mg, 0.061 mmol), and MS4A (85.0
mg) in (CH2Cl)2 (0.50 mL) to afford 46 (32.4 mg, 52%); [α]D23
−15° (c 1.4, CHCl3); 1H NMR (CDCl3, 400 MHz) δ 1.239 (d, J5,6
Found: C, 73.64; H, 7.03%. Calcd for C67H74O13: C, 74.01; H,
6.86%.
(Run 10): Acceptor 24 (16.4 mg, 0.046 mmol) was condensed
with 43 (34.0 mg, 0.046 mol) in the presence of TMSBr (6.6 µL,
0.050 mmol), CoBr2 (11.0 mg, 0.050 mmol), Bu4NBr (16.2 mg,
0.050 mmol), and MS4A (50.0 mg) in (CH2Cl)2 (0.50 mL), fol-
lowed by iterative chromatography to separate unreacted 24 from
42 with DE (30:1) as well as the TK system (10:1) to afford 42
(20.0 mg, 40%).
Methyl O-β-D-Ribofuranosyl-(1→3)-O-α-L-rhamnopyrano-
syl-(1→3)-α-L-rhamnopyranoside (44). Hydrogenation of 42
(38.0 mg, 0.035 mmol) over Pd on C (56 mg) in MeOH (6 mL) at
room temp overnight, removal of the catalyst by filtration, evapo-
ration at 25 °C, and chromatography with the CM system (2:1) af-
forded 44 (8.9 mg, 56%); mp 125–127 °C, [α]D22 −96° (c 0.4,
MeOH); H NMR (D2O, 400 MHz) δ 1.26 (d, J5,6 = 6 Hz, H6 ),
1.28 (d, J5,6 = 6 Hz, H6 ), 3.38 (s, Me), 3.48 (t, J3,4 = J4,5 = 9.5
Hz, H4 ), 3.52 (t, J3,4 = J4,5 = 9.5 Hz, H4 ), 3.67 (dd, J4,5a = 5 Hz,
J5a,5b = 12 Hz, H5a ), 3.69 (dq, J4,5 = 9.5 Hz, J5,6 = 6 Hz, H5 ),
3.75 (dd, J2,3 = 3 Hz, J3,4 = 9.5 Hz, H3 ), 3.81 (dq, J4,5 = 9.5 Hz,
J5,6 = 6 Hz, H5 ), 3.83 (dd, J4,5b = 3 Hz, J5a,5b = 12 Hz, H5b ),
3.87 (dd, J2,3 = 3 Hz, J3,4 = 9.5 Hz, H3 ), 3.99 (dd, J1,2 = 2 Hz,
J2,3 = 3 Hz, H2 ), 4.04 (ddd, J3,4 = 7.5 Hz, J4,5a = 5 Hz, J4,5b = 3
Ⅱ
Ⅰ
= 6 Hz, H6 ), 1.244 (d, J5,6 = 6 Hz, H6 ), 3.37 (dd, J4,5a = 5 Hz,
Ⅲ
J5a,5b = 10.5 Hz, H5a ), 3.48 (dd, J4,5b = 4.5 Hz, J5a,5b = 10.5 Hz,
Ⅲ
Ⅱ
H5b ), 3.56 (t, J3,4 = J4.5 = 9.5 Hz, H4 ), 3.58 (t, J3,4 = J4,5 = 9
Ⅰ
Ⅰ
Hz, H4 ), 3.70 (dq, J4,5 = 9 Hz, J5,6 = 6 Hz, H5 ), 3.75 (dd, J1,2
1.5 Hz, J2,3 = 3 Hz, H2 ), 3.82 (dq, J4,5 = 9.5 Hz, J5,6 = 6 Hz,
H5 ), 3.91 (dd, J1,2 = 1.5 Hz, J2,3 = 4.5 Hz, H2 ), 3.93 (dd, J1,2
=
Ⅰ
Ⅱ
Ⅲ
=
Ⅱ
1.5 Hz, J2,3 = 3 Hz, H2 ), 4.01 (dd, J2,3 = 4.5 Hz, J3,4 = 6.5 Hz,
Ⅲ
Ⅰ
H3 ), 4.12 (dd, J2,3 = 3 Hz, J3,4 = 9 Hz, H3 ), 4.17 (dd, J2,3 = 3
Ⅱ
Hz, J3,4 = 9.5 Hz, H3 ), 4.31 (ddd, J3,4 = 6.5 Hz, J4,5a = 5 Hz, J4,5b
Ⅲ
Ⅰ
= 4.5 Hz, H4 ), 4.81 (d, J1,2 = 1.5 Hz, H1 ), 5.12 (d, J1,2 = 1.5
Hz, H1 ), 5.42 (d, J1,2 = 1.5 Hz, H1 ), 5.85 (m, allyl); 13C NMR
Ⅱ
Ⅲ
Ⅱ
Ⅰ
Ⅰ
(CDCl3, 100 MHz) δ 17.8 (C6 ), 18.0 (C6 ), 68.2 (C5 ), 68.6
1
Ⅱ
Ⅱ
Ⅲ
Ⅰ
Ⅰ
Ⅲ
Ⅱ
(C5 ), 70.8 (C5 ), 77.7 (C3 ), 77.9 (C2 ), 78.0 (C3 ), 78.8 (C3 ),
Ⅰ
Ⅱ
Ⅲ
Ⅲ
Ⅱ
Ⅰ
79.2 (C2 ), 80.1 (C4 ), 80.4 (C2 ), 80.6 (C4 ), 80.8 (C4 ), 96.8
Ⅱ
Ⅰ
Ⅰ
Ⅱ
(C1 , JC1,H1 = 167.8 Hz), 99.8 (C1 , JC1,H1 = 169.2 Hz), 107.1
Ⅲ
Ⅰ
Ⅲ
(C1 , JC1,H1 = 175.0 Hz); 67.8, 116.9, 133.9 (allyl).
Ⅰ
Found: C, 74.60; H, 7.04%. Calcd for C69H76O13: C, 74.44; H,
6.88%.
Ⅱ
Ⅲ
Ⅱ
O-(2,3,5-Tri-O-benzyl-β-D-ribofuranosyl)-(1→3)-O-(2,4-di-
O-benzyl-α-L-rhamnopyranosyl)-(1→3)-2,4-di-O-benzyl-L-
rhamnopyranose (47). Compound 46 (46.3 mg, 0.042 mmol)
was treated with PdCl2 (73.2 mg, 0.41 mmol) and NaOAc (13.6
mg, 0.17 mmol) in aq AcOH (95%, 1.9 mL) at room temp over-
night, followed by purification, as described for 41, to give 47
(27.3 mg, 61%); [α]D22 −10° (c 0.4, CHCl3); 1H NMR (CDCl3, 400
Ⅰ
Ⅲ
Ⅲ
Hz, H4 ), 4.14 (d, J1,2 = 0 Hz, J2,3 = 4.5 Hz, H2 ), 4.22 (dd, J1,2
Ⅱ
= 2 Hz, J2,3 = 3 Hz, H2 ), 4.30 (dd, J2,3 = 4.5 Hz, J3,4 = 7.5 Hz,
Ⅲ
Ⅰ
Ⅱ
H3 ), 4.64 (d, J1,2 = 2 Hz, H1 ), 5.00 (d, J1,2 = 2 Hz, H1 ), 5.19
(s, H1 ); 13C NMR (D2O, 100 MHz) δ 19.25 (C6 ), 19.31 (C6 ),
Ⅲ
Ⅰ
Ⅱ
Ⅲ
Ⅰ
Ⅱ
Ⅰ
57.4 (Me), 64.4 (C5 ), 71.2 (C5 ), 71.7 (C5 ), 72.4 (C2 ), 72.5
Ⅱ
Ⅲ
Ⅱ
Ⅰ
Ⅲ
Ⅰ
Ⅰ
(C2 ), 72.7 (C3 ), 73.6 (C4 ), 74.0 (C4 ), 77.3 (C2 ), 80.7 (C3 ),
MHz) (56%α) δ 1.24 (d, J5,6 = 6 Hz, H6α ), 1.25 (d, J5,6 = 6 Hz,
Ⅱ
Ⅲ
Ⅰ
Ⅱ
Ⅰ
Ⅱ
81.5 (C3 ), 85.2 (C4 ), 103.4 (C1 , JC1,H1 = 169.6 Hz), 104.6
H6α ), 1.26 (d, J5,6 = 6 Hz, H6β ), 1.30 (d, J5,6 = 6 Hz, H6β ),
Ⅱ
Ⅲ
Ⅰ
(C1 , JC1,H1 = 170.9 Hz), 111.2 (C1 , JC1,H1 = 175.5 Hz).
Found: C, 47.10; H, 7.32%. Calcd for C18H32O13: C, 47.36; H,
7.07%.
3.35 (dq, J4,.5 = 9.5 Hz, J5,6 = 6 Hz, H5β ), 3.38 (dd, J4,5a = 5 Hz,
Ⅲ
J5a,5b = 10.5 Hz, H5aα ), 3.39 (dd, J4,5a = 5 Hz, J5a,5b = 10.5 Hz,
Ⅲ
Ⅲ
H5aβ ), 3.50 (dd, J4,5b = 4 Hz, J5a,5b = 10.5 Hz, H5bα ), 3.54
Ⅲ
Benzyl O-(2,3,5-Tri-O-benzyl-β-D-ribofuranosyl)-(1→3)-O-
(2,4-di-O-benzyl-α-L-rhamnopyranosyl)-(1→3)-2,4-di-O-ben-
zyl-α-L-rhamnopyranoside (45) (Run 11). Acceptor 26 (21.2
mg, 0.049 mmol) was condensed with 43 (36.5 mg, 0.049 mol) in
the presence of TMSBr (7.1 µL, 0.054 mmol), CoBr2 (11.7 mg,
0.053 mmol), Bu4NBr (17.3 mg, 0.054 mmol), and MS4A (50.0
mg) in (CH2Cl)2 (0.50 mL) to afford 45 (23.7 mg, 42%), [α]D20
(dd, J4,5b = 4 Hz, J5a,5b = 10.5 Hz, H5bβ ), 3.55 (t, J3,4 = J4,5
=
=
Ⅰ
Ⅰ
9.5 Hz, H4β ), 3.57 (t, J3,4 = J4,5 = 9.5 Hz, H4α ), 3.59 (t, J3,4
Ⅱ
Ⅱ
J4,5 = 9.5 Hz, H4α ), 3.61 (t, J3,4 = J4,5 = 9.5 Hz, H4β ), 3.76
Ⅰ
(dd, J1,2 = 1.5 Hz, J2,3 = 3 Hz, H2α ), 3.78 (dd, J1,2 = 1.5 Hz, J2,3
Ⅰ
Ⅰ
= 3 Hz, H2β ), 3.82 (dq, J4,5 = 9.5 Hz, J5,6 = 6 Hz, H5α ), 3.87
Ⅱ
(dq, J4,5 = 9.5 Hz, J5,6 = 6 Hz, H5β ), 3.88 (dq, J4,5 = 9.5 Hz, J5,6
Ⅱ
Ⅲ
= 6 Hz, H5α ), 3.92 (dd, J1,2 = 1.5 Hz, J2,3 = 4.5 Hz, H2β ), 3.93
1
Ⅲ
−26° (c 0.3, CHCl3); H NMR (CDCl3, 400 MHz) δ 1.24 (d, J5,6
= 6 Hz, H6 ), 1.26 (d, J5,6 = 6 Hz, H6 ), 3.38 (dd, J4,5a = 5 Hz,
(dd, J1,2 = 1.5 Hz, J2,3 = 4.5 Hz, H2α ), 3.94 (dd, J1,2 = 1.5 Hz,
Ⅱ
Ⅰ
Ⅱ
Ⅱ
J2,3 = 3 Hz, H2α ), 3.97 (dd, J1,2 = 1.5 Hz, J2,3 = 3 Hz, H2β ),
Ⅲ
Ⅲ
J5a,5b = 10.5 Hz, H5a ), 3.48 (dd, J4,5b = 4.5 Hz, J5a,5b = 10.5 Hz,
4.018 (dd, J2,3 = 4.5 Hz, J3,4= 6.5 Hz, H3α ), 4.020 (dd, J2,3 =
Ⅲ
Ⅲ
Ⅱ
H5b ), 3.56 (t, J3,4 = J4.5 = 9.5 Hz, H4 ), 3.60 (t, J3,4 = J4,5 = 9.5
4.5 Hz, J3,4 = 6.5 Hz, H3β ), 4.16 (dd, J2,3 = 3 Hz, J3,4 = 9.5 Hz,
Ⅰ Ⅱ Ⅰ
Ⅰ
Ⅰ
Hz, H4 ), 3.74 (dq, J4,5 = 9.5 Hz, J5,6 = 6 Hz, H5 ), 3.77 (dd, J1,2
H3β and H3β ), 4.17 (dd, J2,3 = 3 Hz, J3,4 = 9.5 Hz, H3α and
Ⅱ Ⅰ Ⅱ
Ⅰ
= 2 Hz, J2,3 = 3 Hz, H2 ), 3.82 (dq, J4,5 = 9.5 Hz, J5,6 = 6 Hz,
H3α ), 4.65 (s, H1β ), 5.13 (d, J1,2 = 1.5 Hz, H1α ), 5.18 (d, J1,2
Ⅰ Ⅱ
Ⅱ
Ⅲ
H5 ), 3.92 (dd, J1,2 = 1.5 Hz, J2,3 = 4.5 Hz, H2 ), 3.93 (dd, J1,2
=
= 1.5 Hz, H1α ), 5.22 (d, J1,2 = 1.5 Hz, H1β ), 5.40 (d, J1,2 = 1.5
Ⅲ Ⅲ
Ⅱ
1.5 Hz, J2,3 = 3 Hz, H2 ), 4.01 (dd, J2,3 = 4.5 Hz, J3,4 = 6.5 Hz,
Hz, H1β ), 5.43 (d, J1,2 = 1.5 Hz, H1α ); 13C NMR (CDCl3, 100
Ⅱ Ⅰ Ⅱ Ⅰ
Ⅲ
Ⅰ
H3 ), 4.14 (dd, J2,3 = 3 Hz, J3,4 = 9.5 Hz, H3 ), 4.17 (dd, J2,3 = 3
MHz) δ 17.7 (C6β ), 17.97 (C6α and C6α ), 18.03 (C6β ), 68.3
Ⅱ Ⅰ Ⅱ Ⅲ Ⅲ
Ⅱ
Ⅰ
Hz, J3,4 = 9.5 Hz, H3 ), 4.86 (d, J1,2 = 2 Hz, H1 ), 5.12 (d, J1,2
=
(C5α ), 68.6 (C5α ), 69.2 (C5β ), 70.7 (C5β ), 70.8 (C5α ), 71.6
Ⅰ Ⅲ Ⅲ Ⅰ Ⅱ
1.5 Hz, H1 ), 5.42 (d, J1,2 = 1.5 Hz, H1 ); 13C NMR (CDCl3, 100
(C5β ), 77.7 (C3β ), 77.88 (C3α ), 77.92 (C2α ), 78.6 (C3β ),
Ⅱ Ⅰ Ⅰ Ⅰ Ⅱ
Ⅱ
Ⅲ
Ⅱ
Ⅰ
Ⅰ
Ⅱ
Ⅲ
MHz) δ 17.9 (C6 ), 18.0 (C6 ), 68.4 (C5 ), 68.6 (C5 ), 70.8 (C5 ),
78.7 (C3α ), 78.8 (C3α and C3β ), 78.86 (C2β ), 78.94 (C2β ),
Ⅱ Ⅲ Ⅲ Ⅲ Ⅲ
Ⅰ
Ⅲ
Ⅰ
Ⅱ
Ⅱ
77.8 (C3 ), 77.88 (C3 ), 77.93 (C2 ), 78.8 (C3 ), 79.2 (C2 ), 80.1
79.2 (C2α ), 80.1 (C4α ), 80.2 (C2β and C4β ), 80.3 (C2α ),
Ⅰ Ⅰ Ⅱ Ⅱ Ⅰ
Ⅲ
Ⅲ
Ⅱ
Ⅰ
Ⅰ
Ⅱ
(C4 ), 80.4 (C2 ), 80.6 (C4 ), 80.8 (C4 ), 96.9 (C1 ), 99.8 (C1 ),
80.6 (C4α and C4β ), 80.7 (C4β ), 80.8 (C4α ), 92.6 (C1α ), 93.3
Ⅰ Ⅱ Ⅱ Ⅲ Ⅲ
Ⅲ
107.1 (C1 ).
(C1β ), 99.7 (C1α ), 99.6 (C1β ), 107.06 (C1β ), 107.08 (C1α ).
Found: C, 73.75; H, 6.81%. Calcd for C66H72O13: C, 73.86; H,
6.76%.
Found: C, 75.38; H, 6.86%. Calcd for C73H78O13: C, 75.36; H,
6.76%.
Allyl O-(2,3,5-Tri-O-benzyl-β-D-ribofuranosyl)-(1→3)-O-
(2,4-di-O-benzyl-α-L-rhamnopyranosyl)-(1→3)-2,4-di-O-ben-
zyl-α-L-rhamnopyranoside (46) (Run12). Acceptor 25 (21.5
mg, 0.056 mmol) was condensed with 43 (41.8 mg, 0.056 mol) in
O-β-D-Ribofuranosyl-(1→3)-O-α-L-rhamnopyranosyl-
(1→3)-L-rhamnopyranose (15). Hydrogenation of 47 (29.3
mg, 0.027 mmol) over Pd on C (20 mg) in MeOH (6 mL) contain-
ing H2O (0.1 mL) at room temp overnight, removal of the catalyst

1692 Bull. Chem. Soc. Jpn., 74, No. 9 (2001)
Synthesis of β-D-Ribf-(1→3)-α-L-Rhap-(1→3)-
Ⅰ
Ⅱ
by filtration, evaporation at 25 °C, and chromatography with the
(C1 ), 109.0 (C1 ); 54.6 (Me).
EM system (3:1) afforded 15 (10.2 mg, 84%), mp 135–137 °C,
Found: C, 71.05; H, 6.95%. Calcd for C40H46O9: C, 71.62; H,
6.91%.
[α]D21 −59° (c 0.6, MeOH); H NMR (D2O, 400 MHz) (67%α) δ
1
Ⅰ
Ⅰ
1.26 (d, J5,6 = 6 Hz, H6α ), 1.268 (d, J5,6 = 6 Hz, H6β ), 1.274 (d,
Methyl O-β-D-Ribofuranosyl-(1→3)-α-L-rhamnopyrano-
side (49). Hydrogenation of 16b (23.3 mg, 0.031 mmol) over Pd
on C (28 mg) in MeOH (6 mL) at room temp overnight and chro-
matography with the CM system (2:1) afforded 47 (2.8 mg, 40%);
Ⅱ
Ⅰ
J5,6 = 6 Hz, H6 ), 3.44 (dq, J4,5 = 9 Hz, J5,6 = 6 Hz, H5β ), 3.45
Ⅰ
Ⅱ
(t, J3,4 = J4,5 = 9 Hz, H4β ),3.49 (t, J3,4 = J4,5 = 9.5 Hz, H4 ),
Ⅰ
3.52 (t, J3,4 = J4,5 = 9.5 Hz, H4α ), 3.64 (dd, J2,3 = 3 Hz, J3,4 = 9
Hz, H3β ), 3.68 (dd, J4,5a = 5 Hz, J5a,5b = 12 Hz, H5a ), 3.837
[α]D23 −77° (c 0.8, MeOH); H NMR (D2O, 400 MHz) δ 1.28 (d,
Ⅱ
Ⅲ
1
Ⅲ
Ⅰ
Ⅰ
(dd, J4,5b = 3 Hz, J5a,5b = 12 Hz, H5b ), 3.838 (dq, J4,5 = 9.5 Hz,
J5,6 = 6 Hz, H6 ), 3.38 (s, Me), 3.47 (t, J3,4 = J4,5 = 9.5 Hz, H4 ),
Ⅰ
Ⅱ
Ⅰ
J5,6 = 6 Hz, H5α ), 3.87 (dq, J4,5 = 9.5 Hz, J5,6 = 6 Hz, H5 ),
3.876 (dd, J2,3 = 3 Hz, J3,4 = 9.5 Hz, H3 ), 3.882 (dd, J2,3 = 3 Hz,
3.68 (dd, J4,5a = 5 Hz, J5a,5b = 12.5 Hz, H5a ), 3.71 (dq, J4,5 = 9.5
Hz, J5,6 = 6 Hz, H5 ), 3.73 (dd, J2,3 = 3 Hz, J3,4 = 9.5 Hz, H3 ),
3.83 (dd, J4,5b = 3 Hz, J5a,5b = 12.5 Hz, H5b ), 4.01 (ddd, J3,4 =
7.5 Hz, J4,5a = 5 Hz, J4,5b = 3 Hz, H4 ), 4.09 (dd, J1,2 = 2 Hz, J2,3
Ⅱ
Ⅰ
Ⅰ
Ⅰ
Ⅰ
Ⅱ
J3,4 = 9.5 Hz, H3α ), 3.98 (dd, J1,2 = 2 Hz, J2,3 = 3 Hz, H2α ),
Ⅰ
Ⅱ
3.99 (dd, J1,2 = 1 Hz, J2,3 = 3 Hz, H2β ), 4.01 (ddd, J3,4 = 7.5 Hz,
Ⅲ
Ⅰ
Ⅱ
J4,5a = 5 Hz, J4,5b = 3 Hz, H4 ), 4.15 (d, J1,2 = 0 Hz, J2,3 = 5 Hz,
= 3 Hz, H2 ), 4.14 (d, J1,2 = 0 Hz, J2,3 = 4.5 Hz, H2 ), 4.31 (dd,
Ⅲ
Ⅱ
Ⅱ
Ⅰ
H2 ), 4.23 (dd, J1,2 = 2 Hz, J2,3 = 3 Hz, H2 ), 4.31 (dd, J2,3 = 5
J2,3 = 4.5 Hz, J3,4 = 7.5 Hz, H3 ), 4.67 (d, J1,2 = 2 Hz, H1 ), 5.16
Ⅲ
Ⅰ
Ⅱ
Ⅰ
Hz, J3,4 = 7.5 Hz, H3 ), 4.86 (d, J1,2 = 1 Hz, H1β ), 5.03 (d, J1,2
=
(s, H1 ); 13C NMR (D2O, 100 MHz) δ 19.3 (C6 ), 57.4 (Me), 64.3
2 Hz, H1 ), 5.06 (d, J1,2 = 2 Hz, H1α ), 5.20 (s, H1 ); 13C NMR
(C5 ), 71.0 (C5 ), 72.3 (C2 ), 72.6 (C3 ), 73.6 (C4 ), 77.3 (C2 ),
Ⅱ
Ⅰ
Ⅲ
Ⅱ Ⅰ Ⅰ Ⅱ Ⅰ Ⅱ
Ⅱ
Ⅰ
Ⅰ
Ⅰ
Ⅱ
Ⅰ
Ⅱ
(D2O, 100 MHz) δ 18.65 (C6 ), 18.73 (C6β ), 18.8 (C6α ), 63.8
81.6 (C3 ), 85.1 (C4 ), 103.2 (C1 , JC1,H1 = 170.4 Hz), 111.2 (C1 ,
JC1,H1 = 174.5 Hz).
Ⅲ
Ⅱ
Ⅰ
Ⅱ
Ⅲ
(C5 ), 70.4 (C5 ), 71.0 (C5α ), 71.8 (C2 ), 72.0 (C3 ), 72.6
(C2α ), 72.9 (C4α ), 73.19 (C2β ), 73.23 (C5β1), 73.5 (C4 ), 73.8
Found: C, 46.15; H, 7.23%. Calcd for C12H22O9: C, 46.45; H,
7.15%.
A similar debenzylation of 50 (21.7 mg, 0.032 mmol) over Pd–
C (10%, 46 mg) in MeOH (6 mL) furnished 49 (6.7 mg, 67%).
Ⅰ
Ⅰ
Ⅰ
Ⅱ
Ⅰ
Ⅲ
Ⅱ
Ⅰ
Ⅰ
(C4β ), 76.7 (C2 ), 79.8 (C3 ), 80.8 (C3α ), 82.2 (C3β ), 84.5
(C4 ), 95.4 (C1β , JC1,H1 = 159.7 Hz), 95.9 (C1α , JC1,H1 = 170.0
Ⅲ
Ⅰ
Ⅰ
Ⅱ
Ⅲ
Hz), 103.9 (C1 , JC1,H1 = 170.1 Hz), 110.5 (C1 , JC1,H1 = 175.7
Hz).
Found: C, 44.55; H, 7.00%. Calcd for C17H30O13•H2O: C,
44.35; H, 7.00%.
References
A similar hydrogenation of 47 (11.5 mg, 0.010 mmol) over Pd
on C (10%, 20 mg) in MeOH (6 mL), followed by chromatogra-
phy with EM system, gave 15 (3.3 mg, 76%).
Methyl O-α-L-Rhamnopyranosyl-(1→2)-β-D-ribofurano-
side (48). Hydrogenation of 20a (35.2 mg, 40 mmol) over Pd on
C (40 mg) in MeOH (6 mL) at room temp overnight and chroma-
tography with the CM system (2:1) afforded 48 (33.0 mg, 23%);
[α]D −89° (c 0.25, MeOH); 1H NMR (D2O, 400 MHz) δ 1.28 (d,
1
N. L. Douglas, S. V. Ley, U. Lücking, and S. L. Warriner, J.
Chem. Soc., Perkin Trans. 1, 1998, 51; P. P. Deshpande, H. M.
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Ⅱ
Ⅱ
J5,6 = 6 Hz, H6 ), 3.40 (s, Me), 3.44 (t, J3,4 = J4,5 = 9.5 Hz, H4 ),
Ⅰ
3.59 (dd, J4,5a = 6.5 Hz, J5a,5b = 12 Hz, H5a ), 3.70 (dq, J4,5 = 9.5
Hz, J5,6 = 6 Hz, H5 ), 3.77 (dd, J4,5b = 3 Hz, J4a,4b = 12 Hz,
H5b ), 3.79 (dd, J2,3 = 3.5 Hz, J3,4 = 9.5 Hz, H3 ), 4.02 (dt, J3,4
J4,5a = 6.5 Hz, J4,5b = 3 Hz, H4 ), 4.03 (dd, J1,2 = 2 Hz, J2,3 = 3.5
Ⅱ
Ⅰ
Ⅱ
=
Ⅰ
Ⅱ
Ⅰ
Hz, H2 ), 4.05 (d, J1,2 = 1.5 Hz, J2,3 = 5 Hz, H2 ), 4.25 (dd, J2,3
=
Ⅰ
Ⅱ
5 Hz, J3,4 = 6.5 Hz, H3 ), 4.95 (d, J1,2 = 2 Hz, H1 ), 4.99 (d, J1,2
= 1.5 Hz, H1 ); 13C NMR (D2O, 100 MHz) δ 18.5 (C6 ), 57.4
Ⅰ
Ⅱ
Ⅰ
Ⅱ
Ⅱ
Ⅱ
Ⅰ
(Me), 64.3 (C5 ), 71.2 (C5 ), 71.9 (C3 ), 72.0 (C2 ), 72.2 (C3 ),
Ⅱ
Ⅰ
Ⅰ
Ⅱ
73.9 (C4 ), 82.2 (C2 ), 85.2 (C3 ), 102.9 (C1 , JC1,H1 = 171.3 Hz),
Ⅰ
108.6 (C1 , JC1,H1 = 175.7 Hz); MS (FAB) m/z 333.1162
(M+Na)+. Calcd for C12H22O9Na: 333.11614.
Methyl O-(3,5-Di-O-benzyl-β-D-ribofuranosyl)-(1→3)-2,4-
di-O-benzyl-α-L-rhamnopyranoside (50).
Compound 17b
(57.6 mg, 0.081 mmol) was treated with PdCl2 (20.0 mg, 0.113
mmol) and NaOAc (37.0 mg, 0.45 mmol) in aq AcOH (95%, 3.0
mL) at 60 °C for 2 h, followed by purification, as described for 41,
to give 50 (32.1 mg, 50%); [α]D27 −24° (c 0.5, CHCl3); H NMR
1
Ⅰ
(CDCl3, 300 MHz) δ 1.30 (d, J5,6 = 6 Hz, H6 ), 1.57 (s, OH), 3.29
Ⅱ
(s, Me), 3.45 (dd, J4,5a = 5 Hz, J5a,5b = 10 Hz, H5a ), 3.52 (dd,
Ⅱ
J4,5b = 5 Hz, J5a,5b = 10 Hz, H5b ), 3.54 (t, J3,4 = J4,5 = 9 Hz,
Ⅰ
Ⅰ
H4 ), 3.65 (dq, J4,5 = 9 Hz, J5,6 = 6 Hz, H5 ), 3.74 (dd, J1,2 = 2
Ⅰ
Ⅰ
Hz, J2,3 = 3 Hz, H2 ), 3.993 (dd, J2,3 = 3 Hz, J3,4 = 9 Hz, H3 ),
3.994 (dd, J2,3 = 5 Hz, J3,4 = 6 Hz, H3 ), 4.10 (dd, J1,2 = 1.5 Hz,
Ⅱ
Ⅱ
Ⅱ
J2,3 = 5 Hz, H2 ), 4.19 (dt, J3,4 = 6 Hz, J4,5a = J4,5b = 5 Hz, H4 ),
4.54 (d, J1,2 = 2 Hz, H1 ), 5.27 (d, J1,2 = 1.5 Hz, H1 ); 13C NMR
Ⅰ
Ⅱ
Ⅰ
Ⅰ
Ⅱ
Ⅱ
(CDCl3, 75 MHz) δ 17.9 (C6 ), 67.9 (C5 ), 71.2 (C5 ), 73.8 (C2 ),
78.4 (C2 ), 78.7 (C3 ), 79.0 (C3 ), 80.2 (C4 ), 80.7 (C4 ), 99.2
Ⅰ
Ⅰ
Ⅱ
Ⅱ
Ⅰ

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