A catalytic and stereoselective glycosylation with β-glycosyl fluorides

Article abstract of DOI:10.1002/1522-2675(20000809)83:8<1901::AID-HLCA1901>3.0.CO;2-Q

A catalytic and stereoselective glycosylation of several glycosyl acceptors with β-D-glycosyl fluoride was successfully performed in the presence of a catalytic amount of trityl tetrakis(pentafluorophenyl)borate (TrB(C₆F₅)₄

Full text of DOI:10.1002/1522-2675(20000809)83:8<1901::AID-HLCA1901>3.0.CO;2-Q

Helvetica Chimica Acta ± Vol. 83 (2000)
1901
A Catalytic and Stereoselective Glycosylation with b-Glycosyl Fluorides
by Teruaki Mukaiyama*, Kazuya Takeuchi, Hideki Jona, Hisashi Maeshima, and Terunobu Saitoh
Department of Applied Chemistry, Faculty of Science, Science University of Tokyo, Kagurazaka, Shinjuku-ku,
Tokyo 162-8601
Dedicated to Prof. Dr. Albert Eschenmoser on the occasion of his 75th birthday
A catalytic and stereoselective glycosylation of several glycosyl acceptors with b-d-glycosyl fluoride was
successfully performed in the presence of a catalytic amount of trityl tetrakis(pentafluorophenyl)borate
(TrB(C6F5)4) or trifluoromethanesulfonic acid (TfOH). When TrB(C6F5)4 was used as a catalyst in the solvent
pivalonitrile/(trifluoromethyl)benzene 1 :5, the glycosylation proceeded smoothly to afford the glycosides in
high yields with high b-d-stereoselectivities (see Table 3). Further, the glycosylation by the armed-disarmed
strategy in the presence of this catalyst was established (see Table 4). Similarly, glycosylation catalyzed by the
strong protic acid TfOH afforded the corresponding b-d-glycosides in good-to-excellent yields on treating b-d-
glycosyl fluorides having a 2-O-benzoyl group with various glycosyl acceptors including thioglycosides (see
Tables 6 and 7).
1. Introduction. ± The development of stereoselective glycosylation reactions is one
of the most fundamental topics in carbohydrate chemistry. Among the syntheses of
glycosides including oligosaccharides, the König-Knorr reaction was commonly
employed for a long time; however, the problematic use of a stoichiometric amount
of heavy-metal salt or the unfavorably drastic reaction conditions have not yet been
eluded. In the last 20 years, various types of superb glycosyl donors combined with
activators have been developed [1] for the use in the classical König-Knorr-type
reaction, and the following glycosyl donors were efficiently employed in the synthesis
of saccharide chains: thioglycosides, glycosyl sulfoxides, glycosyl trichloroacetimidates,
glycosyl phosphites, glycosyl phosphates, or other glycosyl donors having P-containing
leaving groups, and pentenyl glycosides. In 1981, it was found in our laboratory that a-
d-glycosides could be prepared with high stereoselectivities on treating b-d-glycosyl
fluorides with various hydroxy compounds, including glycosyl acceptors, in the
presence of stannous chloride (SnCl2)/silver perchlorate (AgClO4) [2] or SnCl2/trityl
perchlorate (TrClO4) [3] as catalysts (Scheme 1). Glycosyl fluorides having a strong
CÀF bond are more stable donors than the corresponding chlorides or bromides due to
their high bond-dissociation energy (CÀF: 552/kJ ´ molÀ1, CÀCl: 397 Æ 29/kJ ´ molÀ1,
CÀBr: 280 Æ 21/kJ ´ molÀ1) [4]. On the other hand, glycosyl fluorides are efficiently
activated by the above-mentioned combined-catalyst systems. Preparative methods
involving glycosyl fluorides combined with suitable activators were widely studied by
many research groups [5]. Activators such as SiF4 [6], Me3SiOTf [6], TiF4 [7], BF3 ´
OEt2 [8], Tf2O [9], [MCl2(Cp)2]/AgClO4 (M ˆ Ti, Zr, Hf; cp ˆ cyclopentadienyl) [10],
[GaClMe2] [11], Yb(OTf)3 [12], and La(ClO4)3 ´ n H2O [13] promoted the glycosylation
of various glycosyl acceptors and allowed the synthesis of many complex oligosac-

1902
Helvetica Chimica Acta ± Vol. 83 (2000)
charide chains. Several examples involving activation of the glycosyl fluoride by a
stoichiometric amount of the activator were studied; in comparison, only a few studies
concerning catalytic glycosylation with glycosyl fluorides were reported [6][8][13].
And, to the best of our knowledge, a catalytic and stereoselective glycosylation of
various free alcohols with glycosyl fluorides has not yet been reported.
Scheme 1
In the last decade, our interests were focused on developing catalytic and
stereoselective glycosylations by choosing suitable combinations of glycosyl donors
and catalysts. We already reported that several glycosyl donors such as 1-O-acylglyco-
sides, sugars with a 1-OH or 1-O-SiMe3 group, 1-O-(phenoxycarbonyl)glycosides, and
thioglycoside could be activated in a catalytic manner [14]. In view of these results, the
exploration of a useful method for the catalytic activation of glycosyl fluorides was
undertaken, and the use of a catalytic amount of trityl tetrakis(pentafluorophenyl)bo-
rate (TrB(C6F5)4) [15] or trifluoromethanesulfonic acid (TfOH) [16] was shown to
activate the glycosyl fluorides efficiently, allowing the synthesis of the corresponding b-
d-glycopyranosides in good yields with high stereoselectivities.
2. Results and Discussion. ± 2.1. Trityl Tetrakis(pentafluorophenyl)borate-Catalyzed
Glycosylation with b-d-Glycosyl Fluorides. Since our first report on the activation of
‡
1-O-acetyl sugars by the triphenylcarbenium ion (trityl cation; Tr ) in a catalytic
manner [17], we focused our investigations on the effect of the counter anion of the
trityl salt. Thus, TrB(C6F5)4 turned out to work catalytically by activating, quite
smoothly, various types of glycosyl donors such as sugars with a 1-OH group [18],
glycosyl phenyl carbonates [19], and thioglycosides [20]. To establish further the
usefulness of this catalyst, the catalytic activation of the anomeric CÀF bond was now
studied.
First, the effects of an added dehydrating agent, an additive, and of the solvent on
the TrB(C6F5)4-catalyzed glycosylation were examined in the model reaction of 2,3,4,6-
tetra-O-benzyl-b-d-glucopyranosyl fluoride (1) with methyl 2,3,4-tri-O-benzyl-a-d-
glucopyranoside (2) (Table 1). In the presence of 20 mol-% of TrB(C6F5)4, the use of
Drierite and pivalonitrile (tBuCN) [20] apparently enhanced the rate of this reaction
giving 3 (Table 1, Entries 4 and 9).

Helvetica Chimica Acta ± Vol. 83 (2000)
1903
Table 1. Effects of Dehydrating Agents and Solvents on the TrB(C6F5)4-Catalyzed Glycosylation of 2 by 1a)
Entry
Dehydrating agentb)
Solvent
Yield/%
a/b-dc)
1
2
3
4
5
6
7
8
9
molecular sieves 3 Š
molecular sieves 4 Š
molecular sieves 5 Š
Drierite
±
±
±
±
±
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
Et2O
toluene
EtCN
tBuCN/CH2Cl2 5 : 1
41
9
38
42
17
9
5
51
89
49 : 51
±
50 : 50
49 : 51
47: 53
±
±
13 : 87
10 : 90
a
)
c
b) With 50 mg on a 0.1-mmol scale of the reaction. ) Ratio determined by HPLC analysis.
Next, to expand the applicability of this reaction, various solvent mixtures and
reaction temperatures were examined in the reaction of 1 with methyl 2,4,6-tri-O-
benzyl-a-d-glucopyranoside (4), the latter exhibiting lower nucleophilicity than 2
(Table 2). The b-d-selectivity was nearly the same when the ratio of pivalonitrile to
CH2Cl2 was reduced from 5 :1 to 1:10 (Table 2, Entries 1 and 2), while the yield of 5
increased when (trifluoromethyl)benzene (PhCF3; ꢀbenzotrifluorideꢁ) was used as a
cosolvent for pivalonitrile. Recently, it was reported [21] that PhCF3 is not only a
useful alternative solvent for reactions currently conducted in CH2Cl2, but also is a
Table 2. Effects of Solvents and Temperatures on the TrB(C6F5)4-Catalyzed Glycosylation of 4 by 1a)
Entry
Solvent
Temp./8
Time/h
Yield/%
a/b-dc)
1
2
3
4
5
6
7
tBuCN/CH2Cl2 5 : 1
tBuCN/CH2Cl2 1 : 10
tBuCN/toluene 1 : 10
tBuCN/PhCF3 1 : 10
tBuCN/PhCF3 1 : 5
tBuCN/PhCF3 1 : 1
tBuCN/PhCF3 1 : 5
0
0
0
0
0
0
4
4
4
4
4
80
75
90
94
95
81
93
17: 83
20 : 80
17: 83
17: 83
18 : 82
16 : 84
9 : 91
4
14
À 10
a
)
c
b) With 100 mg on a 0.1-mmol scale of the reaction. ) Ratio determined by HPLC analysis.

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Helvetica Chimica Acta ± Vol. 83 (2000)
stable solvent with relatively low toxicity. When the reaction was carried out at À108
for 14 h (Table 2, Entry 7), the stereoselectivity was further improved. Several
examples using a catalytic amount of TrB(C6F5)4 are listed in Table 3. In all cases,
the desired b-d-gluco- and b-d-galactopyranosides 7 ± 12 were obtained from 1 or 6 in
good-to-high yields with high stereoselectivities.
In 1988, Fraser-Reid and co-workers introduced the so-called ꢀarmed-disarmedꢁ
chemoselective glycosylation strategy; that is, a C(2)-ether-protected pentenyl glyco-
Table 3. Syntheses of b-d-Gluco- and b-d-Galactopyranosides by TrB(C6F5)4-Catalyzed Glycosylation of 1
or 6a)
ROH
Donor
Cat./mol-%
Temp./8
Time/h
Productb)
Yield/%
a/b-db)
1
1
20
10
À 10
4
1.5
3
3
91
96
3 : 97
5 : 95
0
6
20
À 10
4
7
97
11 : 89
1
1
20
10
À 10
4
1.5
8
8
95
95
8 : 92
11 : 89
0
6
20
À 10
4
9
89
18 : 82
1
1
20
20
À 10
14
4
5
5
93
95
9 : 91
18 : 82
0
6
6
20
20
À 10
À 15
14
18
10
10
81
85
22 : 78
19 : 81
1
1
20
20
À 10
16
6
11
11
63
82
9 : 91
16 : 84
0
6
6
20
20
À 10
À 15
17
24
12
12
70
71
28 : 72
23 : 77
a
)
b) Ratio determined by HPLC analysis.

Helvetica Chimica Acta ± Vol. 83 (2000)
1905
side was chemoselectively coupled with a benzoylated pentenyl glycoside [22]. Chemo-
selective glycosylations have also been developed for other types of glycosides, for
example, thioglycosides, selenoglycosides, glycals, and 2,6-anhydro-2-thiosugars; as
concerns glycosyl fluorides, it was firstly reported by Castillon and co-workers a
chemoselective glycosylation with glycosyl fluorides by using [HfCl2(Cp)2]/AgX (X ˆ
OTf, ClO4) promoter system [23] to give the corresponding disaccharide in a good
yield, and later, Ley and co-workers reported a successful chemoselective glycosylation
based on their cyclic acetal protecting-group strategy [24].
We decided to study the application of the TrB(C6F5)4-catalyzed glycosylation
reaction to the ordinary armed-disarmed glycosylation strategy. At first, the reactivities
of several disarmed glycosyl fluorides were examined by applying the above
glycosylation conditions to the reaction of the glycosyl fluorides 13, 15, and 18 with
methyl 2,3,4-tri-O-benzyl-a-d-glucopyranoside (2) or methyl 2,3,4-tri-O-benzoyl-a-d-
glucopyranoside (16) (Scheme 2). Thus, the reactivity of the disarmed glycosyl
acceptor 2 dramatically decreased, and only 4% of the corresponding disaccharide
14 were obtained. Also, the reactivity of the glucosamine derivative 18 carrying a
dichlorophthaloyl (Cl2Phth) protecting group decreased compared to that of the
corresponding phthaloyl (Phth) derivative 15, furnishing 19 and 17 in 22 and 60% yield,
respectively. These results indicate that the chemoselective glycosylation of glycosyl
fluorides according to the armed-disarmed strategy is feasible. Subsequently, the
Scheme 2

1906
Helvetica Chimica Acta ± Vol. 83 (2000)
starting disarmed sugars 26, 32, and 37 were successfully prepared from 20 via 21 ± 25,
from 27 via 28 ± 31, and from 28 via 33 ± 36, respectively, as shown in Schemes 3, 4, and 5
(see Exper. Part). Indeed, chemoselective glycosylation proceeded when fluoride 1
(armed) and fluorides 26, 32, and 37 (disarmed) were used to afford the corresponding
disaccharides 38 ± 40 in high yields with high stereoselectivities (Table 4).
Scheme 3
a) Cat. NaOMe, CH2Cl2/MeOH. b) PhCH(OMe)2, camphorsulfonic acid (CSA), DMF; 2 steps, 63%. c) BzCl,
Py, cat. 4-(dimethylamino)pyridine (DMAP), CH2Cl2; 89%. d) CF3COOH, Et3SiH, CH2Cl2; 61%. e) Ac2O, Py,
cat. DMAP, CH2Cl2; 96%. f) N-Bromosuccinimide (NBS), (diethylamino)sulfur trifluoride (DAST), CH2Cl2;
31%. g) H2, 10% PdOH/C, CH2Cl2; 90%.
Scheme 4
TBS ˆ tBuMe2Si; for Cl2Phth, see Scheme 2
a) BF3 ´ OEt2, C12H25SH, CH2Cl2; 84%. b) Cat. NaOMe, CH2Cl2/MeOH. c) tBuMe2Si, 1H-imidazole, DMF, 2
steps; 70%. d) BzCl, Py, cat. DMAP, CH2Cl2; 99%. e) NBS, DAST, CH2Cl2; 92%. f) aq. HF soln./MeCN; 48%.
2.2. Trifluoromethanesulfonic-Acid-Catalyzed Glycosylation with b-d-Glycosyl
Fluorides. On reviewing the methods of glycosylation by glycosyl fluorides, no reports
on protic-acid activation could be found. Applying the concept of hard and soft acids
‡
and bases (HSAB) rules, however, the proton (H ) is considered to be fluorophilic
because of its hard character and should act as a catalyst for glycosylation by glycosyl
fluoride. Indeed, glycosyl fluorides were activated by a catalytic amount of TfOH
(5 mol-%), and b-d-glycopyranosides were obtained in good to excellent yields on
treatment with several glycosyl acceptors.
First, 5 mol-% of protic-acid catalysts such as CF3COOH, MeSO3H, or TfOH were
employed in the reaction of 2,3,4,6-tetra-O-benzyl-b-d-glucopyranosyl fluoride (1)

Helvetica Chimica Acta ± Vol. 83 (2000)
1907
Scheme 5
Arˆ 4-MeOC6H4; PMB ˆ 4-MeOC6H4CH2; for Cl2Phth, see Scheme 2
a) Cat. NaOMe, CH2Cl2/MeOH. b) p-Anisaldehyde dimethyl acetal, cat. CSA, DMF. c) Ac2O, cat. DMAP, Py;
3 steps 50% (based on 59% conversion). d) NaBH3CN, Me3SiCl, THF/MeCN; 80%. e) Ac2O, cat. DMAP, Py/
CH2Cl2; 99%. f) NBS, DAST, CH2Cl2; 93%. g) DDQ, CH2Cl2/H2O; 70%.
Table 4. Chemoselective TrB(C6F5)4-Catalyzed Glycosylation ofGlycosyl Fluorides 26, 32, and 37 by 1a)
Entry
Acceptor
Cat./mol-%
Temp./8
Time/h
Product
Yield/%
a/b-db)
1
2
3
26
32
37
20
10
10
0
3
21
15
38
39
40
80
86
84
17 : 83
9 : 91
8 : 92
À 35 to À108
À 35 to À158
a
)
b) Ratio determined by HPLC analysis.
with methyl 2,3,4-tri-O-benzyl-a-d-glucopyranoside (2). TfOH efficiently accelerated
the glycosylation by 1 in CH2Cl2 at room temperature to give 83% yield of the
corresponding disaccharide (Table 5, Entry 4), while CF3COOH and MeSO3H did not.
Next, various donors that possess other types of leaving groups were examined under
the same conditions to evaluate the suitability of the protic-acid-catalyzed glycosylation
(Table 5). Interestingly, glycosyl bromide and chloride were not activated efficiently, in
contrast to the glycosyl fluorides (Table 5, Entries 1 ± 4). Glycosyl acetate and
carbonate and the sugar with a 1-OH group (Table 5, Entries 5 ± 7) reacted with
acceptors and furnished the desired disaccharide 3 in moderate yields (not optimized).
Since thioglycoside was not activated at all under the same conditions (Table 5,

1908
Helvetica Chimica Acta ± Vol. 83 (2000)
a
Table 5. TfOH-Catalyzed Glycosylation of 2 ofby Various Glycosyl Donors
)
Entry
X
Yield/%
a/b-db)
Entry
X
Yield/%
a/b-db)
1
2
3
4
Br (a)
Cl (a)
F (a)
F (b)
9
6
87
83
45 : 55
52 : 48
66 : 34
67: 33
5
6
7
8
OH (mix)
OAc (a)
OCOOPh (b)
SEt (b)
51
75
61
0
73 : 27
68 : 32
72 : 28
±
a
)
b) Ratios determined by HPLC analysis.
Entry 8), the present reaction should be applicable to the orthogonal glycosylation
methodology (vide infra).
To study the influence of the protecting groups of the glycosyl donors, differently
protected glycosyl fluorides were examined under the above reaction conditions
(Table 6). Both armed sugars 1 and 41 (Table 6, Entries 1 and 2) reacted smoothly with
2 in the presence of 5 mol-% TfOH (see also Table 5), while disarmed sugars 13 and 42
gave poor results (Table 6, Entries 3 and 4). On the other hand, 2-O-benzoyl-3,4,6-tri-
O-benzyl-protected glycosyl fluoride 43 [25] was efficiently activated and gave the
corresponding glycoside stereoselectively in good yield (Table 6, Entry 5). Thus, the
reactivity of the glycosyl fluoride increased drastically just by changing the 3,4,6-O-
Table 6. TfOH-Catalyzed Glycosylation of 2 by Differently Protected Glycosyl Fluoridesa)
Entry
Donor
Product yield/%
a/b-db)
1
2
3
4
5
6c)
1
41
13
42
43
43
83 (for P6, see 1)
87 (for P6, see 1)
11 (for P6, see 13)
0
80 (for P6, see 43)
97 (for P6, see 43)
67: 33b)
66 : 34b)
b-d
±
b-d
b-d
a
)
c
b) Ratio determined by HPLC analysis. ) With 1.2 equiv. of donor at 08 for 4 h.

Helvetica Chimica Acta ± Vol. 83 (2000)
1909
Table 7. TfOH-Catalyzed b-d-Selective Glycosylation ofVarious Glycosyl Acceptors by Glycosyl Donors 43
and 44a)
Entry
Acceptor (ROH)
Donor
Time/h
Product
Yield/%
43
44
4
45
46
97
93
1
2.5
43
44
6
9
47
48
87
87
2
3
4
5
43
44
18
12
49
50
67
70
43
44
5
51
52
85
81
1.5
43
44
8
53
54
81
71
3.5
a
)
benzoyl protecting groups to benzyl ones [26] (Table 6, Entries 4 and 5). Also the
neighboring-group participation worked well, resulting in a 1,2-trans glycosidic bond.
Optimization of the reaction conditions (08, 1.2 equiv. of donor 43, 1 equiv. of acceptor
2) raised the yield to 97% (Entry 6).

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Helvetica Chimica Acta ± Vol. 83 (2000)
To illustrate further the efficiency of the TfOH-catalyzed glycosylation, several
examples are summarized in Table 7. Indeed, glycosylation by the b-d-glucosyl fluoride
43 or the b-d-galactosyl fluoride 44 gave the corresponding disaccharides in good-to-
excellent yields with b-d-configuration, as expected. It is remarkable that orthogonal
glycosylation [27] with thioglycosides proceeded to give the disaccharides in good
yields without damaging the thioglycosidic linkage at the reducing terminus (Table 7,
Entries 4 and 5).
Thus, a catalytic and stereoselective glycosylation by the b-d-glycosyl fluorides 43
and 44 of several glycosyl acceptors was successfully carried out in the presence of
5 mol-% of TfOH furnishing the corresponding disaccharides in high yields with the
expected stereoselectivitiy. It should be noted that the present reaction is the first
example of an activation of the anomeric CÀF bond by a catalytic amount of protic
acid.
3. Conclusion. ± A catalytic and b-d-selective glycosylation reaction with b-d-
glycosyl fluorides was successfully carried out in the presence of a catalytic amount of
trityl tetrakis(pentafluorophenyl)borate (TrB(C6F5)4) or trifluoromethanesulfonic
acid (TfOH). It is interesting to note that an a-d-selective glycosylation took place
on treating a b-d-glycosyl fluoride with glycosyl acceptors in the presence of such
combined activators as SnCl2/AgClO4 in Et2O as solvent [2]. Thus, very convenient
methods for the stereoselective preparation of both a- and b-d-glycosides are now
established starting simply from b-d-glycosyl fluorides.
The present research is partially supported by Grant-in-Aids for Scientific Research from the Ministry of
Education, Science, Sports, and Culture. We thank Asahi Glass Engineering Co. Ltd. for providing TrB(C6F5)4
and Mr. Ohsawa, Banyu Pharmaceutical Company, for many mass-spectrometry analyses.
Experimental Part
General. All reactions were carried out under Ar in dried glassware, unless otherwise noted. CH2Cl2 and
pivalonitrile were distilled from P2O5 and then from CaH2 and dried (molecular sieves, 4 Š). Toluene and
(trifluoromethyl)benzene were distilled from P2O5 and dried (molecular sieves, 4 Š). Dry THF and Et2O were
purchased from Kanto Chemical. Powdered and pre-dried (at 2608/0.1 Torr) molecular sieves 3 Š, 4 Š, and 5 Š
were used in glycosylation reactions. Sufficiently crashed and pre-dried (at 2608/0.1 Torr) Drierite from W. A.
Hammond Drierite Company was used in the glycosylations. All reagents were purchased from Tokyo Kasei
Kogyo, Kanto Chemical, or Aldrich and used without further purification, unless otherwise noted. Column
chromatography (CC): silica gel 60 (Merck) or Wakogel B5F. HPLC: Hitachi LC-Organizer, L-4000 UV
detector, L-6200 intelligent pump, and D-2500 chromato-integrator with Shodex SIL-5B (normal phase; 120 Š,
5 mm, 4.6  250 mm) and YMC Jꢀsphere M80 (reversed phase; 80 Š, 4 mm, 4.6  250 mm). M.p.: Yanaco-MP-S3
micro melting-point apparatus. Optical rotations: Jasco-DIP-360 or Jasco-P-1020 digital polarimeter. IR
Spectra: Horiba-FT-300 infrared spectrometer; nÄ in cmÀ1. NMR Spectra: Jeol-JNM-EX300L, Jeol-JNM-LA-400,
and Jeol-JNM-LA-500 FT-NMR spectrometers; CDCl3 solns. with SiMe4 and CHCl3 as internal standard; d in
ppm, J in Hz. High-resolution MS: Jeol-JMS-SX102A instrument with 4-nitrobenzyl alcohol as matrix.
Glycosylation with Catalyst TrB(C6F5)4: General Procedure (GP(TrB(C6F5)4)). To a stirred suspension of
TrB(C6F5)4 (18.5 mg, 0.02 mmol) and Drierite (100 mg) in PhCF3/tBuCN 5 :1 (3.0 ml), methyl 2,3,4-tri-O-
benzyl-a-d-glucopyranoside (2; 46.5 mg, 0.10 mmol) and 2,3,4,6-tetra-O-benzyl-b-d-glucopyranosyl fluoride (1;
70.5 mg, 0.13 mmol) in PhCF3/tBuCN 5 :1 (1.5 ml) were added successively at À108. The mixture was stirred for
4 h at À108. Then the reaction was quenched by adding sat. aq. NaHCO3 soln. (10 ml). The mixture was filtered
through Celite and extracted with CH2Cl2 (3Â). The combined org. layer was washed with brine, dried
(Na2SO4), and evaporated, and the resulting residue purified by prep. TLC (silica gel): methyl 2,3,4-tri-O-

Helvetica Chimica Acta ± Vol. 83 (2000)
1911
benzyl-6-O-(2,3,4,6-tetra-O-benzyl-d-glucopyranosyl)-a-d-glucopyranoside (3; 89.6 mg, 90.8%). The ratio was
determined by HPLC (hexane/AcOEt): a/b-d 3 :97. For data, see [28].
Methyl 2,4,6-Tri-O-benzyl-3-O-(2,3,4,6-tetra-O-benzyl-d-glucopyranosyl)-a-d-glucopyranoside (5). Ac-
cording to GP (TrB(C6F5)4), at À108 for 14 h. Yield 93%, a/b-d 9 :91. For data, see [29].
Methyl 2,3,4-Tri-O-benzyl-6-O-(2,3,4,6-tetra-O-benzyl-d-galactopyranosyl)-a-d-glucopyranoside (7). Ac-
cording to GP (TrB(C6F5)4), at À108 for 14 h. Yield 97%, a/b-d 11 :89. For data, see [30].
Methyl 2,3,4-Tri-O-benzoyl-6-O-(2,3,4,6-tetra-O-benzyl-d-glucopyranosyl)-a-d-glucopyranoside (8). Ac-
cording to GP (TrB(C6F5)4), at À108 for 4 h. Yield 95%, a/b-d 8 :92. For data, see [31].
Methyl 2,3,4-Tri-O-benzoyl-6-O-(2,3,4,6-tetra-O-benzyl-d-galactopyranosyl)-a-d-glucopyranoside (9). Ac-
cording to GP (TrB(C6F5)4), at À108 for 4 h. Yield 89%, a/b-d 18 :82. For data, see [31].
Methyl 2,4,6-Tri-O-benzyl-3-O-(2,3,4,6-tetra-O-benzyl-d-galactopyranosyl)-a-d-glucopyranoside (10). Ac-
cording to GP (TrB(C6F5)4), at À158 for 18 h. Yield 85%, a/b-d 19 :81.
Data of b-d-10: White crystals. M.p. 100 ± 1028. [a]2D3 ˆ ‡18.1 (c ˆ 1.0, CHCl3). IR (KBr): 2916, 2870, 1458,
1
1365, 1157, 1072, 740, 702. H-NMR (500 MHz, CDCl3): 3.28 (s, 3 H); 3.45 (dd, J ˆ 8.5, 4.9, 1 H); 3.49 (dd, J ˆ
9.8, 3.7, 1 H); 3.52 ± 3.74 (m, 7 H); 3.76 (dd, J ˆ 9.4, 3.4, 1 H); 3.86 (dd, J ˆ 9.5, 7.9, 1 H); 3.98 ± 4.03 (m, 1 H);
4.30 ± 4.38 (m, 4 H); 4.40 (d, J ˆ 11.9, 1 H); 4.44 (d, J ˆ 3.5, 1 H); 4.51 (d, J ˆ 12.2, 1 H); 4.59 (d, J ˆ 11.3, 1 H);
4.62 ± 4.70 (m, 2 H); 4.77 (d, J ˆ 12.2, 1 H); 4.80 (d, J ˆ 12.2, 1 H); 4.93 (d, J ˆ 11.6, 1 H); 4.96 ± 5.07 (m, 2 H);
4.98 (d, J ˆ 7.9, 1 HÀC(1')); 7.00 ± 7.56 (m, 35 H). 13C-NMR (CDCl3): 55.0; 67.9; 68.5; 69.5; 72.6; 72.7; 73.4; 73.6;
73.8; 74.0; 74.8; 74.9; 75.2; 75.7; 80.3; 81.0; 82.5; 98.0; 102.7; 127.2; 127.3; 127.4; 127.6; 127.70; 127.74; 127.8; 127.9;
128.0; 128.1; 128.2; 128.30; 128.33; 128.36; 128.39; 128.9; 137.9; 138.0; 138.2; 138.7; 139.2. HR-MS: 1009.4495
‡
‡
(C62H66NaO11, [M ‡ Na] ; calc. 1009.4503).
Methyl 2,3,6-Tri-O-benzyl-4-O-(2,3,4,6-tetra-O-benzyl-d-glucopyranosyl)-a-d-glucopyranoside (11). Ac-
cording to GP (TrB(C6F5)4), at À108 for 16 h. Yield 63%, a/b-d 9 :91. For data, see [28].
Methyl 2,3,6-Tri-O-benzyl-4-O-(2,3,4,6-tetra-O-benzyl-d-galactopyranosyl)-a-d-glucopyranoside (12). Ac-
cording to GP (TrB(C6F5)4), at À158 for 24 h. Yield 71%, a/b-d 23 :77. For data, see [32].
Disarmed Sugar 26 (see Scheme 3). Dodecyl 4,6-O-Benzylidene-1-thio-b-d-glucopyranoside (21). To a soln.
of dodecyl 2,3,4,6-tetra-O-acetyl-1-thio-b-d-glucopyranoside (20) [33] (3.69 g, 6.76 mmol) in CH2Cl2 (10 ml)
and MeOH (20 ml), 28% NaOMe (261 mg, 1.35 mmol) in MeOH was added at 08. After stirring for 30 min at
r.t., the mixture was acidified with Amberlite ꢂ IR-120 cation exchange resin (until ca. pH 5). After filtration of
the mixture and removal of the solvent, the residue was dried in vacuo. The crude product obtained was used
without further purification. To a soln. of the crude product and camphorsulfonic acid (CSA; 0.470 g,
2.03 mmol) in DMF (34 ml) benzaldehyde dimethyl acetal (1.21 ml, 8.11 mmol) was added at r.t. After stirring
for 5 h at ca. 20 Torr, sat. aq. NaHCO3 soln. was added. The mixture was extracted with Et2O, washed with H2O
and brine, dried (Na2SO4), and evaporated and the residue purified by CC (hexane/AcOEt 5 :1 ! 3 :1): 21
(1.93 g, 63.0%). White solid. M.p. 96 ± 988. [a]D23 ˆ À37.1 (c ˆ 1.1, CHCl3). IR (KBr): 3425, 2924, 2854, 1720,
1281, 1257, 1111, 1088, 987, 702. 1H-NMR (300 MHz, CDCl3): 0.88 (t, J ˆ 6.3, 3 H); 1.14 ± 1.40 (m, 18 H); 1.41 ±
1.68 (m, 2 H); 2.69 (t, J ˆ 7.5, 2 H); 3.35 ± 3.57 (m, 3 H); 3.63 ± 3.82 (m, 2 H); 4.31 (dd, J ˆ 10.5, 4.8, 1 H); 4.40
(d, J ˆ 9.9, 1 H); 5.51 (s, 1 H); 7.33 ± 7.40 (m, 3 H); 7.46 ± 7.50 (m, 2 H). 13C-NMR (CDCl3): 14.0; 22.6; 28.8; 29.1;
29.3; 29.4; 29.5; 29.6; 29.9; 30.5; 31.4; 31.8; 68.5; 70.4; 73.2; 74.4; 80.3; 86.6; 101.8; 126.3; 128.2; 129.2; 136.9. HR-
‡
‡
MS: 475.2505 (C25H40NaO5S , [M ‡ Na] ; calc. 475.2494).
Dodecyl 2,3-Di-O-benzoyl-4,6-O-benzylidene-1-thio-b-d-glucopyranoside (22). To a soln. of 21 (6.00 g,
13.3 mmol) and DMAP (162 mg, 1.30 mmol) in CH2Cl2 (67 ml), pyridine (2.6 ml, 31.9 mmol) and BzCl (3.30 ml,
29.3 mmol) were added successively at 08. After stirring for 12 h at r.t., sat. aq. NaHCO3 soln. was added. The
mixture was extracted with Et2O, the extract washed with sat. aq. CuSO4 soln., H2O, and brine, dried (Na2SO4)
and evaporated, and the residue purified by CC (hexane/AcOEt 5 :1): 22 (7.80 g, 89%). White solid. M.p. 99 ±
1028. [a]2D3 ˆ ‡7.2 (c ˆ 1.3, CHCl3). IR (KBr): 2924, 2854, 1720, 1265, 1095, 987, 702. 1H-NMR (300 MHz,
CDCl3): 0.88 (t, J ˆ 6.6, 3 H); 1.15 ± 1.39 (m, 18 H); 1.40 ± 1.70 (m, 2 H); 2.67 ± 2.77 (m, 2 H); 3.70 ± 3.78
(m, 1 H); 3.83 ± 3.97 (m, 2 H); 4.45 (dd, J ˆ 10.2, 4.8, 1 H); 4.80 (d, J ˆ 9.9, 1 H); 5.51 (dd, J ˆ 9.9, 9.9, 1 H); 5.55
(s, 1H); 5.81 (dd, J ˆ 9.9, 9.3, 1 H); 7.27 ± 7.61 (m, 11 H); 7.92 ± 8.13 (m, 4 H). 13C-NMR (CDCl3): 14.1; 22.7;
28.7; 29.1; 29.3; 29.4; 29.5; 29.6; 30.3; 31.9; 68.5; 70.97; 71.00; 73.2; 78.7; 84.7; 101.4; 126.1; 128.2; 128.26; 128.32;
128.4; 129.0; 129.1; 129.3; 129.7; 129.8; 130.2; 133.1; 133.2; 133.7; 136.7; 165.3; 165.6. HR-MS: 683.3010
‡
‡
(C39H48NaO7S , [M ‡ Na] ; calc. 683.3018).
Dodecyl 2,3-Di-O-benzoyl-6-O-benzyl-1-thio-b-d-glucopyranoside (23). To
a soln. of 22 (6.00 g,
9.10 mmol) and Et3SiH (7.30 ml, 45.4 mmol) in CH2Cl2 (30 ml), CF3COOH (4.20 ml, 54.5 mmol) was added
at 08. After stirring for 2 h at r.t., sat. aq. NaHCO3 soln. was added. The mixture was extracted with Et2O, the
extract washed with sat. aq. CuSO4 soln., H2O, and brine, dried (Na2SO4), and evaporated, and the residue

1912
Helvetica Chimica Acta ± Vol. 83 (2000)
purified by CC (hexane/AcOEt 3 :1): 23 (3.60 g, 61.0%). Colorless oil. [a]2D3 ˆ ‡33.6 (c ˆ 1.1, CHCl3). IR (neat):
3448, 2954, 2931, 2870, 1736, 1705, 1288, 1250, 1103, 1065, 710. 1H-NMR (400 MHz, CDCl3): 0.88 (t, J ˆ 6.8,
3 H); 1.20 ± 1.45 (m, 18 H); 1.50 ± 1.61 (m, 2 H); 2.68 ± 2.75 (m, 2 H); 3.69 ± 3.74 (m,1 H); 3.83 ± 3.89 (m, 2 H);
3.97 (dd, J ˆ 9.3, 9.0, 1 H); 4.60 (d, J ˆ 12.0, 1 H); 4.65 (d, J ˆ 12.0, 1 H); 4.68 (d, J ˆ 9.5, 1 H); 5.44 (dd, J ˆ 9.5,
9.5, 1 H); 5.50 (dd, J ˆ 9.5, 9.0, 1 H); 7.25 ± 7.51 (m, 11 H); 7.94 ± 7.97 (m, 4 H). 13C-NMR (CDCl3): 14.1; 22.7;
28.7; 29.1; 29.3; 29.46; 29.54; 29.6; 30.1; 31.9; 60.4; 70.1; 70.2; 70.9; 73.7; 77.5; 78.7; 83.7; 127.7; 127.8; 128.29;
128.33; 128.40; 128.44; 129.0; 129.3; 129.8; 129.9; 130.1; 130.2; 133.3; 137.6; 165.3; 167.0. HR-MS: 685.3193
‡
‡
(C39H50NaO7S , [M ‡ Na] ; calc. 685.3175).
Dodecyl 4-O-Acetyl-2,3-di-O-benzoyl-6-O-benzyl-1-thio-b-d-glucopyranoside (24). To a soln. of 23 (1.16 g,
1.75 mmol) and DMAP (43 mg, 0.35 mmol) in CH2Cl2 (8.8 ml) and pyridine (0.42 ml, 5.2 mmol), Ac2O (0.33 ml,
3.3 mmol) was added at r.t. After stirring for 12 h, sat. aq. NaHCO3 soln. was added. The mixture was extracted
with Et2O, the extract washed with sat. aq. CuSO4 soln., H2O, and brine, dried (Na2SO4), and evaporated, and
the residue purified by CC (hexane/AcOEt 5 :1): 24 (1.19 g, 96%). Colorless foam. [a]2D4 ˆ ‡44.5 (c ˆ 1.1,
1
CHCl3). IR (KBr): 2916, 2854, 1728, 1273, 1227, 1095, 1065, 710. H-NMR (400 MHz, CDCl3): 0.88 (t, J ˆ 6.3,
3 H); 1.20 ± 1.40 (m, 18 H); 1.50 ± 1.64 (m, 2 H); 1.84 (s, 3 H); 2.65 ± 2.80 (m, 2 H); 3.64 ± 3.66 (m, 2 H); 4.52 ±
4.64 (m, 1 H); 4.54 (d, J ˆ 11.7, 1 H); 4.61 (d, J ˆ 11.7, 1 H); 4.70 (d, J ˆ 9.9, 1 H); 5.33 (dd, J ˆ 9.9, 9.6, 1 H); 5.45
(dd, J ˆ 9.9, 9.6, 1 H); 5.66 (dd, J ˆ 9.6, 9.6, 1 H); 7.25 ± 7.39 (m, 9 H); 7.46 ± 7.53 (m, 2 H); 7.88 ± 7.96 (m, 4 H).
13C-NMR (CDCl3): 14.1; 20.5; 22.7; 28.8; 29.1; 29.3; 29.48; 29.55; 29.60; 29.63; 30.0; 31.9; 69.0; 69.3; 70.5; 73.6;
74.4; 77.7; 83.8; 127.7; 127.8; 128.4; 128.9; 129.2; 129.76; 129.81; 133.2; 133.3; 137.7; 165.1; 165.8; 169.5. HR-MS:
‡
‡
727.3265 (C41H52NaO8S , [M ‡ Na] ; calc. 727.3281).
4-O-Acetyl-2,3-di-O-benzoyl-6-O-benzyl-b-d-glucopyranosyl Fluoride (25). To a soln. of 24 (170 mg,
0.241 mmol) in CH2Cl2 (4.8 ml), (diethylamino)sulfur trifluoride (DAST; 0.0480 ml, 0.362 mmol) and N-
bromosuccinimide (NBS; 55.7 mg, 0.313 mmol) were added at À238. After stirring for 5 h at r.t., sat. aq.
NaHCO3 soln. was added. The mixture was extracted with Et2O, the extract washed with H2O and brine, dried
(Na2SO4), and evaporated, and the residue purified by prep. TLC (hexane/AcOEt 2 :1): 25 (39.5 mg, 31%).
White crystals. M.p. 131 ± 1328. [a]2D4 ˆ ‡86.9 (c ˆ 1.1, CHCl3). IR (KBr): 1736, 1273, 1111, 710. 1H-NMR
(500 MHz, CDCl3): 1.87 (s, 3 H); 3.69 (d, J ˆ 4.3, 2 H); 4.03 (m, 1 H); 4.55 (d, J ˆ 11.9, 1 H); 4.62 (d, J ˆ 11.9,
1 H); 5.44 ± 5.66 (m, 4 H); 7.27 ± 7.41 (m, 9 H); 7.49 ± 7.55 (m, 2 H); 7.92 ± 7.99 (m, 4 H). 13C-NMR (CDCl3): 20.5;
68.1; 68.5; 71.3; 71.7; 71.9; 72.0; 73.56; 73.60; 73.65; 106.56 (d, J ˆ 219.5, C(1)); 127.8; 127.9; 128.40; 128.44; 128.6;
128.7; 129.81; 129.84; 133.5; 137.4; 164.8; 165.6; 169.3.
4-O-Acetyl-2,3-di-O-benzoyl-b-d-glucopyranosyl Fluoride (26). To a soln. of 25 (37.2 mg, 0.0712 mmol) in
CH2Cl2 (3 ml), 20% PdOH/C (Aldrich) was added at r.t. under Ar. After purging with H2 (1 atm) and stirring
for 5 h, H2 was removed. Then the catalyst was filtered off, the mixture evaporated, and the residue purified by
prep. TLC (hexane/AcOEt 1:1): 26 (27.8 mg, 90%). White crystals. M.p. 169 ± 1708. [a]2D3 ˆ ‡113.3 (c ˆ 1.1,
CHCl3). IR (KBr): 1736, 1273, 1111. 1H-NMR (400 MHz, CDCl3): 2.00 (s, 3 H); 2.40 ± 2.50 (br., 1 H); 3.73 ± 3.78
(m, 1 H); 3.85 ± 3.92 (m, 2 H); 5.44 (dd, J ˆ 9.5, 9.3, 1 H); 5.48 ± 5.73 (m, 4 H; half of the d of HaÀC(1) was
detected, J ˆ 6.4); 7.38 (d, J ˆ 7.6, 2 H); 7.41 (d, J ˆ 7.6, 2 H); 7.50 ± 7.58 (m, 2 H); 7.93 ± 8.00 (m, 2 ). 13C-NMR
(CDCl3): 20.6; 61.2; 67.7; 71.5 (d, J ˆ 28.1, C(2)); 71.75; 71.83; 71.9; 74.6; 106.6 (d, J ˆ 218.9, C(1)); 128.44;
‡
‡
128.49; 128.54; 128.6; 129.8; 129.9; 133.6; 164.8; 165.5; 169.9. HR-MS: 455.1109 (C22H21FNO8 , [M ‡ Na] ; calc.
455.1118).
Disarmed Sugar 32 (see Scheme 4). Dodecyl 3,4,6-Tri-O-acetyl-2-deoxy-2-(4,5-dichlorophthalimido)-1-thio-
b-d-glucopyranoside (28). To a soln. of 1-acetoxy-3,4,6-tri-O-acetyl-2-deoxy-2-(4,5-dichlorophthalimido)-b-d-
glucopyranoside (27) [34] (84.3 g, 154 mmol) in CH2Cl2 (310 ml), dodecane-1-thiol (44.3 ml, 185 mmol) and
BF3 ´ OEt2 (22.8 ml, 185 mmol) were added successively at 08. After stirring for 24 h at r.t., sat.aq. NaHCO3 soln.
was added. The mixture was extracted with AcOEt, the extract washed with H2O and brine, dried (Na2SO4), and
evaporated, and the residue purified by CC (hexane/AcOEt 3 :1 ! 1:1): 28 (89.5 g, 84.0%). White crystals. M.p.
117 ± 1188. [a]D24 ˆ ‡44.0 (c ˆ 1.1, CHCl3). IR (KBr): 2923, 2854, 1751, 1720, 1380, 1226, 1041. 1H-NMR
(300 MHz, CDCl3): 0.88 (t, J ˆ 6.6, 3 H); 1.18 ± 1.40 (m, 18 H); 1.40 ± 1.62 (m, 2 H); 1.88 (s, 3 H); 2.04 (s, 3 H);
2.11 (s, 3 H); 2.54 ± 2.72 (m, 2 H); 3.87 (ddd, J ˆ 9.8, 4.7, 2.2, 1 H); 4.17 (dd, J ˆ 12.3, 2.2, 1 H); 4.31 (dd, J ˆ 12.3,
4.7, 1 H); 4.34 (dd, J ˆ 9.8, 9.3, 1 H); 5.17 (dd, J ˆ 10.2, 10.5, 1 H); 5.42 (d, J ˆ 10.5, 1 H); 5.76 (dd, J ˆ 10.2, 9.3,
1 H); 7.93 (s, 1 H); 7.95 (s, 1 H). 13C-NMR (CDCl3): 14.1; 20.5; 20.6; 20.8; 28.7; 29.1; 29.3; 29.50; 29.56; 29.61;
29.64; 30.3; 31.9; 54.1; 62.2; 68.6; 71.5; 75.9; 81.1; 125.8; 169.4; 170.2; 170.7. HR-MS: 710.1911
‡
‡
(C32H43Cl2NNaO9S , [M ‡ Na] ; calc. 710.1933).
Dodecyl 6-O-[(tert-Butyl)dimethylsilyl]-2-deoxy-2-(4,5-dichlorophthalimido)-1-thio-b-d-glucopyranoside
(29). To a soln. of 28 (34.7 g, 49.7 mmol) in CH2Cl2 (90 ml) and MeOH (10 ml), 28% NaOMe (2.9 g,
14.9 mmol) in MeOH was slowly added at r.t. After stirring for 30 min, TsOH was added (until ca. pH 5), the

Helvetica Chimica Acta ± Vol. 83 (2000)
1913
solvent evaporated, and the residue dried in vacuo. The crude product thus obtained was used in the next step
without further purification. To a soln. of the crude product in DMF (100 ml), 1H-imidazole (3.70 g, 54.7 mmol)
and tBuMe2SiCl (8.20 g, 54.7 mmol) were successively added at r.t. After stirring for 5 h, sat. aq. NaHCO3 soln.
was added, the mixture extracted with Et2O, the extract washed with H2O and brine, dried (Na2SO4), and
evaporated, and the residue purified by CC (hexane/AcOEt 3 :1): 29 (23.4 g, 70.0%). Colorless oil. [a]D24
ˆ
À12.4 (c ˆ 1.1, CHCl3). IR (neat): 2947, 2908, 2862, 1774, 1713. 1H-NMR (500 MHz, CDCl3): 0.01 (s, 6 H); 0.76
(t, J ˆ 6.8, 3 H); 0.79 (s, 9 H); 1.07 ± 1.19 (m, 18 H); 1.28 ± 1.42 (m, 2 H); 1.91 ± 2.54 (m, 2 H); 2.66 (br. s, 1 H);
3.39 ± 3.45 (m, 1 H); 3.50 (dd, J ˆ 9.5, 8.9, 1 H); 3.57 ± 3.62 (br., 1 H); 3.71 (dd, J ˆ 10.1, 7.1, 1 H); 3.88 (dd, J ˆ
10.1, 4.5, 1 H); 4.03 (dd, J ˆ 10.4, 9.2, 1 H); 4.24 (dd, J ˆ 9.5, 9.2, 1 H); 5.13 (d, J ˆ 10.4, 1 H); 7.79 (s, 1 H); 7.81
(s, 1 H). 13C-NMR (CDCl3): À5.5; 14.1; 18.2; 22.7; 25.8; 28.7; 29.1; 29.3; 29.50; 29.54; 29.57; 29.61; 29.65; 29.8;
‡
‡
31.9; 55.4; 65.2; 72.2; 75.4; 81.0; 139.1. HR-MS: 698.2451 (C32H51Cl2NNaO6SSi , [M ‡ Na] ; calc. 698.2481).
Dodecyl 3,4-Di-O-benzoyl-6-O-[(tert-butyl)dimethylsilyl]-2-deoxy-2-(4,5-dichlorophthalimido)-1-thio-b-
d-glucopyranoside (30). To a soln. of 29 (4.00 g, 5.90 mmol) and DMAP (73.0 mg, 0.60 mmol) in CH2Cl2
(24 ml), pyridine (2.40 ml, 29.7 mmol) and BzCl (2.70 ml, 23.4 mmol) were added successively at r.t. After
stirring for 12 h, sat. aq. NaHCO3 soln. was added, the mixture extracted with Et2O, the extract washed with H2O
and brine, dried (Na2SO4), and evaporated, and the residue purified by CC (hexane/AcOEt 15 :1): 30 (5.20 g,
99.4%). Colorless oil. [a]2D4 ˆ ‡37.7 (c ˆ 1.4, CHCl3). IR (neat): 2962, 2862, 1720, 1373, 1265, 1034, 841.
1H-NMR (500 MHz, CDCl3): 0.01 (s, 6 H); 0.84 (s, 9 H); 0.85 (t, J ˆ 6.7, 3 H); 1.20 ± 1.28 (m, 18 H); 1.40 ± 1.60
(m, 2 H); 2.58 ± 2.64 (m,1 H); 2.69 ± 2.76 (m, 1 H); 3.79 (dd, J ˆ 11.6, 5.2, 1 H); 3.83 (dd, J ˆ 11.6, 2.5, 1 H); 3.91
(ddd, J ˆ 9.5, 5.2, 2.5, 1 H); 4.52 (dd, J ˆ 10.7, 10.4, 1 H); 5.51 (d, J ˆ 10.4, 1 H); 5.53 (dd, J ˆ 9.8, 9.5, 1 H); 6.16
(dd, J ˆ 10.7, 9.8, 1 H); 7.25 (dd, J ˆ 7.3, 7.3, 2 H); 7.32 (dd, J ˆ 7.3, 7.3, 2 H); 7.40 (dd, J ˆ 7.3, 7.3, 1 H); 7.46
(dd, J ˆ 7.3, 7.3, 1 H); 7.74 (d, J ˆ 7.3, 2 H); 7.78 (s, 1 H); 7.88 (d, J ˆ 7.3, 2 H); 7.93 (s, 1 H). 13C-NMR (CDCl3):
À5.4; 14.1; 18.3; 22.7; 25.8; 28.8; 29.1; 29.3; 29.5; 29.59; 29.62; 29.65; 31.9; 54.5; 62.8; 69.8; 72.3; 79.4; 80.6;
125.69; 125.73; 128.3; 128.5; 129.1; 129.7; 129.8; 130.3; 130.8; 133.2; 133.3; 139.1; 139.3; 165.0; 165.8. HR-MS:
‡
‡
906.3016 (C46H59Cl2NNaO8SSi , [M ‡ Na] ; calc. 906.3005).
3,4-Di-O-benzoyl-6-O-[(tert-butyl)dimethylsilyl]-2-deoxy-2(4,5-dichlorophthalimido)-b-d-glucopyranosyl
Fluoride (31). As described for 25, with 30 (2.00 g, 2.30 mmol), CH2Cl2 (45 ml), DAST (0.479 ml, 3.40 mmol),
and NBS (523 mg, 2.90 mmol). The residue was purified by CC (hexane/AcOEt 10 :1): 31 (1.47 g, 92.0%).
White amorphous solid. [a]2D4 ˆ ‡49.2 (c ˆ 1.1, CHCl3). IR (KBr): 1736, 1381, 1265, 1111, 841, 710. 1H-NMR
(400 MHz, CDCl3): 0.01 (s, 6 H); 0.84 (s, 9 H); 3.74 ± 3.92 (m, 2 H); 3.95 ± 4.03 (m, 1 H); 4.57 (ddd, J ˆ 12.7, 10.7,
7.8, 1 H); 5.64 (dd, J ˆ 9.8, 9.5, 1 H); 6.12 (dd, J ˆ 10.7, 9.5, 1 H); 6.17 (dd, J ˆ 52.5, 7.8, 1 H); 7.22 ± 7.49 (m, 6 H);
7.71 ± 7.75 (m, 2 H); 7.86 ± 7.91 (m, 4 H). 13C-NMR (CDCl3): À5.5; 14.2; 18.3; 25.6; 25.8; 55.4 (d, J ˆ 24.1, C(2));
62.2; 69.0; 70.6 (d, J ˆ 10.1, C(3)); 75.1 (d, J ˆ 5.0, C(4)); 104.3 (d, J ˆ 215.6, C(1)); 125.8; 128.2; 128.4; 128.9;
‡
129.7; 129.8; 129.9; 130.4; 133.4; 133.5; 139.4; 164.9; 165.6; 165.8. HR-MS: 724.1290 (C34H44Cl2FNNaO8Si ,
‡
[M ‡ Na] ; calc. 724.1312).
3,4-Di-O-benzoyl-2-deoxy-2-(4,5-dichlorophthalimido)-b-d-glucopyranosyl Fluoride (32). To a soln. of 31
(4.70 g, 6.70 mmol) in MeCN (66 ml), 46% aq. hydrofluoric acid (3.5 ml) was added at r.t. After stirring for
40 min, sat. aq. NaHCO3 was added, the mixture extracted with Et2O, the extract washed with H2O and brine,
dried (Na2SO4), and evaporated, and the residue purified by CC (hexane/AcOEt 10 :1): 32 (1.90 g, 48.0%).
White crystals. M.p. 124 ± 1268. [a]2D4 ˆ ‡61.1 (c ˆ 1.2, CHCl3). IR (KBr): 1782, 1713, 1373, 1257, 1095, 710.
1H-NMR (400 MHz, CDCl3): 2.50 ± 2.75 (br., 1 H); 3.80 (dd, J ˆ 12.9, 3.9, 1 H); 3.94 (dd, J ˆ 12.9, 1.7, 1 H);
4.27 ± 4.30 (m, 1 H); 4.65 (ddd, J ˆ 12.4, 10.7, 7.8, 1 H); 5.61 (dd, J ˆ 9.9, 9.3, 1 H); 6.25 (dd, J ˆ 52.4, 7.8, 1 H);
6.28 (dd, J ˆ 10.5, 9.9, 1 H); 7.25 ± 7.57 (m, 6 H); 7.77 ± 7.79 (m, 2 H); 7.90 ± 7.96 (m, 4 H). 13C-NMR (CDCl3):
55.2 (d, J ˆ 23.8, C(2)); 60.9; 68.9; 70.0 (d, J ˆ 10.3, C(3)); 74.6 (d, J ˆ 4.1, C(4)); 104.2 (d, J ˆ 216.0, C(1));
125.7; 125.8; 128.0; 128.2; 128.4; 128.5; 129.8; 129.9; 130.3; 133.6; 133.8; 139.5; 165.5; 165.6; 165.8. HR-MS:
‡
‡
610.0433 (C28H20Cl2FNNaO8 , [M ‡ Na] ; calc. 610.0448).
Disarmed Sugar 37 (see Scheme 5). Dodecyl 3-O-Acetyl-2-deoxy-2-(4,5-dichlorophthalimido)-4,6-O-(4-
methoxybenzylidene)-1-thio-b-d-glucopyranoside (33). To a soln. of 28 (35.1 g, 51.0 mmol) in CH2Cl2 (90 ml)
and MeOH (10 ml), 28% NaOMe (2.9 g, 15.2 mmol) in MeOH was added at r.t. After stirring for 30 min, the
mixture was acidified with TsOH (until ca. pH 5), the solvent evaporated, and the residue dried in vacuo. The
crude product thus obtained was used without further purification. To a soln. of the crude product and CSA
(3.60 g, 15.3 mmol) in DMF (100 ml), p-anisaldehyde dimethyl acetal (10.4 ml, 61.2 mmol) was added at r.t. and
stirred at ca. 20 Torr for 5 h. Then pyridine (41.0 ml, 510 mmol), DMAP (1.20 g, 5.10 mmol), and Ac2O (29.0 ml,
306 mmol) were added successively. After stirring for further 12 h, sat. aq. NaHCO3 soln. was added, the mixture
extracted with Et2O, the org. layer washed with sat. aq. CuSO4 soln., H2O, and brine, dried (Na2SO4), and
evaporated, and the residue purified by CC (hexane/AcOEt 5 :1): 33 (11.8 g, 50% yield based on 59%

1914
Helvetica Chimica Acta ± Vol. 83 (2000)
conversion) as white crystals and 41% of recovered 28. 33: M.p. 45 ± 488. [a]2D2 ˆ ‡4.0 (c ˆ 1.1, CHCl3). IR
(KBr): 2924, 1728, 1373, 1227, 1095, 1034. 1H-NMR (300 MHz, CDCl3): 0.88 (t, J ˆ 6.4, 3 H); 1.08 ± 1.40
(m, 18 H); 1.40 ± 1.54 (m, 2 H); 1.90 (s, 3 H); 2.55 ± 2.73 (m, 2 H); 3.80 (s, 3 H); 3.74 ± 3.85 (m, 3 H); 4.30
(dd, J ˆ 10.5, 9.9, 1 H); 4.40 (m, 1 H); 5.50 (s, 1 H); 5.50 (d, J ˆ 10.5, 1 H); 5.83 (dd, J ˆ 9.9, 9.0, 1 H); 6.88
(d, J ˆ 8.8, 2 H); 7.38 (d, J ˆ 8.8, 2 H); 7.92 (s, 1 H); 7.95 (s, 1 H). 13C-NMR (CDCl3): 14.1; 20.6; 22.7; 28.6; 29.1;
29.3; 29.45; 29.55; 29.60; 29.63; 30.4; 31.9; 54.7; 55.2; 68.4; 70.5; 78.9; 81.6; 101.6; 113.5; 125.6; 125.7; 127.5; 129.2;
‡
‡
130.2; 130.7; 139.2; 139.4; 160.1; 165.4; 165.8; 170.3. HR-MS: 744.2169 (C36H45Cl2NNaO8S , [M ‡ Na] ; calc.
744.2141).
Dodecyl 3-O-Acetyl-2-deoxy-2-(4,5-dichlorophthalimido)-4-O-(4-methoxybenzyl)-1-thio-b-d-glucopyrano-
side (34). To a suspension of 33 (10.9 g, 14.1 mmol) and 3 Š molecular sieves (10.9 g) in THF (150 ml) and
MeCN (110 ml), NaBH3CN (8.10 g, 129 mmol) was added at 08. Then Me3SiCl (20.0 ml, 158 mmol) was slowly
added at 08 within 30 min. After stirring for 2 h, H2O was added and the mixture poured into sat. aq. NaHCO3
soln. The mixture was extracted with AcOEt, the extract washed with brine, dried (Na2SO4), and evaporated,
and the residue purified by CC (hexane/AcOEt 3 :1): 34 (8.70 g, 80%). Colorless oil. [a]2D1 ˆ ‡3.2 (c ˆ 1.5,
CHCl3). IR (neat): 2916, 2854, 1720, 1373, 1242, 1080, 1041. 1H-NMR (400 MHz, CDCl3): 0.88 (t, J ˆ 6.6, 3 H);
1.10 ± 1.40 (m, 18 H); 1.40 ± 1.55 (m, 2 H); 2.56 ± 2.68 (m, 2 H); 3.81 (s, 3 H); 3.70 ± 3.83 (m, 4 H); 4.23 (dd, J ˆ
10.5, 10.2, 1 H); 4.51 (d, J ˆ 11.7, 1 H); 4.56 (d, J ˆ 11.7, 1 H); 5.41 (d, J ˆ 10.5, 1 H); 5.61 (dd, J ˆ 10.5, 8.5, 1 H);
6.88 (d, J ˆ 6.3, 2 H); 7.26 (d, J ˆ 5.4, 2 H); 7.92 (s, 1 H); 7.95 (s, 1 H). 13C-NMR (CDCl3): 14.1; 20.7; 22.7; 28.7;
29.1; 29.4; 29.53; 29.59; 29.63; 29.7; 30.2; 31.9; 54.1; 55.3; 70.1; 71.6; 73.5; 74.0; 77.7; 80.9; 113.9; 125.7; 129.5;
‡
‡
130.3; 130.8; 139.2; 139.5; 159.4; 165.5; 165.9; 171.0. HR-MS: 746.2303 (C36H47Cl2NNaO8S , [M ‡ Na] ; calc.
746.2297).
Dodecyl 3,6-Di-O-acetyl-2-deoxy-2-(4,5-dichlorophthalimido)-4-O-(4-methoxybenzyl)-1-thio-b-d-gluco-
pyranoside (35). To a soln. of 34 (5.00 g, 6.50 mmol) and DMAP (79 mg, cat.) in CH2Cl2 (20 ml) and pyridine
(4.2 ml), Ac2O (0.90 ml, 9.8 mmol) was added at 08. After stirring for 3 h at r.t., sat. aq. NaHCO3 soln. was
added. The mixture was extracted with Et2O, the extract washed with sat. aq. CuSO4 soln., H2O, and brine, dried
(Na2SO4), and evaporated, and the residue purified by CC (hexane/AcOEt 4 :1): 35 (5.30 g, 99%). Colorless oil.
[a]2D1 ˆ ‡64.1 (c ˆ 1.1, CHCl3). IR (neat): 2908, 2854, 1743, 1380, 1218, 1041. 1H-NMR (400 MHz, CDCl3): 0.88
(t, J ˆ 6.6, 3 H); 1.08 ± 1.40 (m, 18 H); 1.40 ± 1.54 (m, 2 H); 1.87 (s, 3 H); 1.92 (s, 3 H); 2.57 ± 2.72 (m, 2 H); 3.55 ±
3.62 (m, 2 H); 3.80 (s, 3 H); 3.77 ± 3.86 (m, 1 H); 4.33 (dd, J ˆ 10.5, 9.8, 1 H); 4.47 (d, J ˆ 11.7, 1 H); 4.52 (d, J ˆ
11.7, 1 H); 5.17 (dd, J ˆ 9.8, 9.5, 1 H); 5.40 (d, J ˆ 10.5, 1 H); 5.75 (dd, J ˆ 9.8, 9.5, 1 H); 6.87 (d, J ˆ 8.3, 2 H);
7.25 (d, J ˆ 8.6, 2 H); 7.95 (s, 1 H); 7.97 (s, 1 H). 13C-NMR (CDCl3): 14.1; 20.4; 20.6; 22.6; 28.6; 29.0; 29.3; 29.45;
29.49; 29.51; 29.55; 29.60; 30.1; 31.8; 54.2; 55.2; 68.6; 69.5; 71.6; 73.1; 80.8; 113.6; 125.7; 129.4; 129.7; 130.2; 130.6;
‡
‡
139.2; 139.4; 159.2; 165.2; 165.7; 169.5; 170.3. HR-MS: 788.2407 (C38H49Cl2NNaO9S , [M ‡ Na] ; calc.
788.2403).
3,6-Di-O-acetyl-2-deoxy-2-(4,5-dichlorophthalimido)-4-O-(4-methoxybenzyl)-b-d-glucopyranosyl Fluoride
(36). To a soln. of 35 (4.10 g, 5.40 mmol) in CH2Cl2 (100 ml), DAST (1.10 ml, 8.10 mmol) and NBS (1.25 g,
7.02 mmol) were added at À238. After stirring for 5 h at r.t., the mixture was poured into sat. aq. NaHCO3 soln.
and extracted with CH2Cl2, the extract washed with H2O and brine, dried (Na2SO4), and evaporated, and the
residue purified by CC (hexane/AcOEt 4 :1): 36 (2.70 g, 93%). White crystals. M.p. 119 ± 1248. [a]2D2 ˆ ‡84.7
(c ˆ 1.0, CHCl3). IR (KBr): 1759, 1720, 1381, 1227, 1111, 1034. 1H-NMR (400 MHz, CDCl3): 1.88 (s, 3 H); 2.10
(s, 3 H); 3.72 ± 3.90 (m, 2 H); 3.80 (s, 3 H); 4.23 ± 4.39 (m, 2 H); 4.49 (dd, J ˆ 12.0, 1.8, 1 H); 4.55 (d, J ˆ 11.7,
1 H); 4.61 (d, J ˆ 11.7, 1 H); 5.73 (dd, J ˆ 10.6, 8.7, 1 H); 6.08 (dd, J ˆ 52.5, 7.8, 1 H); 6.87 (d, J ˆ 8.6, 2 H); 7.18
(d, J ˆ 8.6, 2 H); 7.95 (s, 2 H). 13C-NMR (CDCl3): 20.6; 20.8; 55.4 (d, J ˆ 26.4, C(2)); 62.2; 72.6; 72.7; 73.0 (d, J ˆ
5.8); 74.4; 74.8; 104.0 (d, J ˆ 214.8, C(1)); 114.0; 125.8; 129.0; 129.7; 130.4; 139.6; 159.6; 165.7; 170.1; 170.6. HR-
‡
‡
MS: 583.0825 (C26H24Cl2NO9 , M ; calc. 583.0812).
3,6-Di-O-acetyl-2-deoxy-2-(4,5-dichlorophthalimido)-b-d-glucopyranosyl Fluoride (37). To a soln. of 36
(2.00 g, 3.40 mmol) in CH2Cl2 (64.4 ml) and H2O (3.6 ml) was added 2,3-dichloro-5,6-dicyano-1,4-benzoquinone
(DDQ; 932 mg, 4.10 mmol) at r.t. After stirring for 12 h, sat. aq. NaHCO3 soln. was added. The mixture was
extracted with Et2O, the extract washed with H2O and brine, dried (Na2SO4), and evaporated, and the residue
purified by CC (hexane/AcOEt 2 :1): 37 (2.70 g, 93%). White crystals. M.p. 186 ± 1888. [a]2D2 ˆ ‡95.3 (c ˆ 1.0,
CHCl3). IR (KBr): 1720, 1380, 1218, 1110, 1049. 1H-NMR (300 MHz, CDCl3): 1.90 (s, 3 H); 2.10 (s, 3 H); 3.68 ±
3.83 (m, 3 H); 4.47 (ddd, J ˆ 12.6, 10.2, 7.8, 1 H); 5.20 (dd, J ˆ 9.6, 9.3, 1 H); 5.80 (dd, J ˆ 10.2, 9.3, 1 H); 6.09
(dd, J ˆ 52.5, 7.8, 1 H); 7.96 (s, 1 H); 7.97 (s, 1 H). 13C-NMR (CDCl3): 20.4; 20.6; 55.1 (d, J ˆ 23.6, C(2)); 60.9;
68.3; 69.8 (d, J ˆ 9.4, C(3)); 74.2 (d, J ˆ 4.4, C(4)); 104.1 (d, J ˆ 216.4, C(1)); 125.9; 130.3; 139.7; 165.6; 170.1;
‡
‡
170.2. HR-MS: 486.0142 (C18H16Cl2FNNaO8 , [M ‡ Na] ; calc. 486.0153).

Helvetica Chimica Acta ± Vol. 83 (2000)
1915
4-O-Acetyl-2,3-di-O-benzoyl-6-O-(2,3,4,6-tetra-O-benzyl-b-d-glucopyranosyl)-b-d-glucopyranosyl Fluo-
ride (38). According to GP (TrB(C6F5)4), at 08 for 3 h. Yield 80%, a/b-d 17:83. 38 (b-d): White crystals.
M.p. 163 ± 1648. [a]D22 ˆ ‡48.1 (c ˆ 0.85, CHCl3). IR (KBr): 3032, 2877, 1736, 1273, 1095, 1072, 741, 702. 1H-NMR
(500 MHz, CDCl3): 3.44 ± 3.52 (m, 2 H); 3.61 ± 3.75 (m, 4 H); 3.80 ± 3.84 (m, 1 H); 4.08 ± 4.15 (m, 2 H); 4.48
(d, J ˆ 7.9, HÀC(1')); 4.52 (d, J ˆ 10.7, 1 H); 4.53 (d, J ˆ 12.2, 1 H); 4.54 (d, J ˆ 10.7, 1 H); 4.62 (d, J ˆ 12.2, 1 H);
4.72 (d, J ˆ 10.7, 1 H); 4.79 (d, J ˆ 11.0, 1 H); 4.83 (d, J ˆ 10.7, 1 H); 4.95 (d, J ˆ 11.0, 1 H); 5.00 (d, J ˆ 10.7, 1 H);
5.33 (dd, J ˆ 9.5, 8.9, 1 H); 5.46 ± 5.60 (m, 1 H); 5.54 (dd, J ˆ 53.7, 6.1, 1 H); 5.65 (dd, J ˆ 8.5, 8.5, 1 H); 7.10 ± 7.60
(m, 26 H); 7.92 (s, 1 H); 7.93 (d, J ˆ 7.0, 2 H); 7.97 (s, 1 H); 7.98 (d, J ˆ 7.0, 2 H). 13C-NMR (CDCl3): 20.4; 68.2;
68.7; 69.1; 71.5 (d, J ˆ 29.0, C(2)); 71.8 (d, J ˆ 8.3, C(3)); 73.4; 73.8 (d, J ˆ 3.6, C(4)); 74.66; 74.74; 74.8; 75.6;
76.6; 77.5; 82.1; 84.5; 104.1; 106.6 (d, J ˆ 219.0, C(1)); 127.58; 127.62; 127.65; 127.75; 127.86; 127.90; 128.30;
128.34; 128.43; 128.48; 128.6; 128.7; 129.8; 129.9; 133.5; 138.0; 138.4; 138.5; 164.9; 165.5; 169.5. HR-MS:
‡
‡
977.3538 (C56H55FNaO13 , [M ‡ Na] ; calc. 977.3524).
3,4-Di-O-benzoyl-2-deoxy-2-(4,5-dichlorophthalimido)-6-O-(2,3,4,6-tetra-O-benzyl-b-d-glucopyranosyl)-b-d-
glucopyranosyl Fluoride (39). According to GP (TrB(C6F5)4), at À35 to À108 for 21 h. Yield 86%, a/b-d 9 :91.
39 (b-d): White crystals. M.p. 150 ± 1518. [a]2D4 ˆ ‡38.7 (c ˆ 1.2, CHCl3). IR (KBr): 2924, 2854, 1728, 1381, 1273,
1
1103, 1072, 741, 710. H-NMR (500 MHz, CDCl3): 3.32 ± 3.41 (m, 2 H); 3.45 ± 3.70 (m, 4 H); 3.80 (dd, J ˆ 10.3,
7.6, 1 H); 4.07 (d, J ˆ 10.3, 1 H); 4.15 ± 4.22 (m, 1 H); 4.38 (d, J ˆ 7.6, HÀC(1')); 4.37 ± 4.49 (m, 3 H); 4.57
(ddd, J ˆ 12.2, 10.7, 7.6, 1 H); 4.61 (d, J ˆ 11.0, 1 H); 4.69 (d, J ˆ 11.0, 1 H); 4.72 (d, J ˆ 10.7, 1 H); 4.85 (d, J ˆ
11.0, 1 H); 4.91 (d, J ˆ 11.0, 1 H); 5.47 (dd, J ˆ 9.8, 9.2, 1 H); 6.12 (dd, J ˆ 10.7, 9.2, 1 H); 6.17 (dd, J ˆ 52.5, 7.6,
1 H); 7.05 ± 7.45 (m, 26 H); 7.66 (d, J ˆ 7.3, 2 H); 7.79 ± 7.83 (m, 4 H). 13C-NMR (CDCl3): 55.3 (d, J ˆ 23.8, C(2));
68.5; 68.7; 69.5; 70.3 (d, J ˆ 11.8, C(3)); 73.4; 73.8 (d, J ˆ 5.5, C(4)); 74.8; 74.9; 75.6; 77.5; 82.1; 84.5; 104.1; 104.2
(d, J ˆ 209.2, C(1)); 125.8; 127.5; 127.6; 127.7; 128.20; 128.23; 128.31; 128.36; 128.46; 129.67; 129.72; 129.77;
‡
129.84; 130.3; 133.55; 133.59; 138.0; 138.4; 138.6; 139.5; 165.1; 165.5. HR-MS: 1132.2871 (C62H54Cl2FNNaO13
[M ‡ Na] ; calc. 1132.2854).
,
‡
3,6-Di-O-acetyl-2-deoxy-2-(4,5-dichlorophthalimido)-4-O-(2,3,4,6-tetra-O-benzyl-b-d-glucopyranosyl)-b-d-
glucopyranosyl Fluoride (40). According to GP (TrB(C6F5)4), at À35 to À158 for 15 h. Yield 84%, a/b-d 8 :92.
40 (b-d): White crystals. M.p. 62 ± 658. [a]2D4 ˆ ‡37.0 (c ˆ 1.0, CHCl3). IR (KBr): 1751, 1728, 1373, 1234, 1103,
1065, 741, 702. 1H-NMR (500 MHz, CDCl3): 1.87 (s, 3 H); 1.99 (s, 3 H); 3.43 ± 3.55 (m, 2 H); 3.60 ± 3.81
(m, 5 H); 3.98 ± 4.10 (m, 2 H); 4.36 ± 4.43 (m, 1 H); 4.46 (d, J ˆ 7.3, HÀC(1')); 4.50 ± 4.57 (m, 2 H); 4.63 (d, J ˆ
12.2, 1 H); 4.71 (d, J ˆ 10.7, 1 H); 4.79 (d, J ˆ 11.0, 1 H); 4.82 (d, J ˆ 10.7, 1 H); 4.94 (d, J ˆ 11.0, 1 H); 4.98
(d, J ˆ 10.7, 1 H); 5.10 (dd, J ˆ 10.1, 9.5, 1 H); 5.76 (dd, J ˆ 10.0, 9.5, 1 H); 6.07 (dd, J ˆ 52.2, 7.6, 1 H); 7.10 ± 7.40
(m, 20 H); 7.94 (s, 2 H). 13C-NMR (CDCl3): 20.3; 20.5; 55.1 (d, J ˆ 23.8, C(2)); 68.9; 70.5 (d, J ˆ 9.3, C(3));
73.36; 73.41; 73.5; 74.7; 74.8; 74.9; 75.7; 77.5; 82.0; 84.5; 103.9 (d, J ˆ 217.2, C(1)); 104.0; 125.8; 127.57; 127.61;
127.69; 127.74; 127.8; 127.9; 130.3; 138.3; 138.4; 138.5; 165.5; 169.4; 170.1. HR-MS: 1008.2584
‡
‡
(C52H50Cl2FNNaO13 , [M ‡ Na] ; calc. 1008.2541).
2-O-Benzoyl-3,4,6-tri-O-benzyl-b-d-galactopyranosyl Fluoride (44). To a soln. of ethyl 2-O-benzoyl-3,4,6-
tri-O-benzyl-1-thio-b-d-galactopyranoside [35] (90.7 mg, 0.15 mmol) in CH2Cl2 (1.3 ml), DAST (0.020 ml,
0.17 mmol) was added at À238. After stirring for 2 h at r.t., sat. aq. NaHCO3 soln. was added. The mixture was
extracted with Et2O, the extract washed with H2O and brine, dried (Na2SO4), and evaporated, and the residue
purified by prep. TLC (hexane/AcOEt 3 :1): 44 (51.5 mg, 61.8%). Colorless oil. [a]2D4 ˆ ‡45.0 (c ˆ 0.99, CHCl3).
IR (neat): 1728, 1265, 1111, 1057, 741, 702. 1H-NMR (300 MHz, CDCl3): 3.66 ± 3.81 (m, 4 H); 3.99 ± 4.04
(m, 1 H); 4.43 ± 4.67 (m, 5 H); 4.95 (d, J ˆ 11.4, 1 H); 5.28 (dd, J ˆ 53.1, 6.3, 1 H); 5.71 (ddd, J ˆ 12.0, 9.6, 6.6,
1 H); 7.14 ± 7.61 (m, 18 H); 8.02 (d, J ˆ 7.2, 2 H). 13C-NMR (CDCl3): 63.4; 71.5 (d, J ˆ 24.3, C(2)); 71.9; 73.6;
74.1; 74.4; 78.3 (d, J ˆ 9.3, C(3)); 107.5 (d, J ˆ 217.4, C(1)); 127.66; 127.73; 127.81; 127.9; 128.0; 128.3; 128.4;
‡
‡
128.5; 129.6; 129.9; 133.2; 137.3; 137.6; 138.0; 165.1. HR-MS: 579.2170 (C34H33FNaO6 , [M ‡ Na] ; calc.
579.2159).
Glycosylation with Catalyst TfOH: General Procedure (GP(TfOH)). To a stirred suspension of Drierite
(100 mg), 2-O-benzoyl-3,4,6-tri-O-benzyl-b-d-glucopyranosyl fluoride (43; 66.8 mg, 0.12 mmol), and methyl
2,3,4-tri-O-benzyl-a-d-glucopyranoside (46.5 mg, 0.10 mmol) in CH2Cl2 (2.5 ml), TfOH (0.75 mg in toluene,
0.04 ml, 5.0 mmol) was added dropwise at 08. The mixture was stirred for 4 h at 08 and then the reaction
quenched by adding sat. aq. NaHCO3 soln. (2 ml). The mixture was diluted with AcOEt and 1n HCl, the aq.
layer extracted with AcOEt, the combined org. layer washed with H2O and brine, dried (MgSO4), and
evaporated, and the resulting residue purified by prep. TLC (silica gel): methyl 6-O-(2-O-benzoyl-3,4,6-tri-O-
benzyl-b-d-glucopyranosyl)-2,3,4-tri-O-benzyl-a-d-glucopyranoside (45; 97.2 mg, 97.1%). White solid. M.p.
1
131 ± 1338. [a]2D1 ˆ ‡26.5 (c ˆ 1.1, CHCl3). IR (KBr): 1720, 1273, 1072, 746, 702. H-NMR (500 MHz, CDCl3):
3.19 (s, 3 H); 3.37 (dd, J ˆ 9.5, 9.2, 1 H); 3.43 (dd, J ˆ 9.5, 3.7, 1 H); 3.53 ± 3.58 (m, 1 H); 3.63 ± 3.74 (m, 3 H);

1916
Helvetica Chimica Acta ± Vol. 83 (2000)
3.76 (dd, J ˆ 10.6, 1.5, 1 H); 3.81 (dd, J ˆ 9.5, 8.9, 1 H); 3.86 (dd, J ˆ 9.5, 9.2, 1 H); 4.13 (d, J ˆ 9.2, 1 H); 4.27
(d, J ˆ 11.0, 1 H); 4.43 (d, J ˆ 11.0, 1 H); 4.47 (d, J ˆ 3.4, 1 H); 4.52 (d, J ˆ 7.9, HÀC(1')); 4.54 ± 4.62 (m, 5 H);
4.65 (d, J ˆ 11.0, 1 H); 4.67 (d, J ˆ 11.0, 1 H); 4.72 (d, J ˆ 12.2, 1 H); 4.73 (d, J ˆ 11.0, 1 H); 4.78 (d, J ˆ 10.7,
1 H); 4.87 (d, J ˆ 11.0, 1 H); 5.35 (dd, J ˆ 9.5, 7.9, 1 H); 6.98 ± 7.03 (m, 2 H); 7.10 ± 7.35 (m, 30 H); 7.42 ± 7.47
(m, 1 H); 7.90 ± 7.95 (m, 2 H). 13C-NMR (CDCl3): 54.9; 68.0; 69.4; 73.3; 73.4; 73.6; 74.6; 75.0; 75.1; 75.40; 75.44;
77.4; 78.0; 79.6; 81.9; 82.8; 97.9; 101.2; 127.37; 127.43; 127.56; 127.63; 127.65; 127.78; 127.81; 127.84; 127.97; 127.99;
128.1; 128.20; 128.23; 128.30; 128.33; 128.38; 128.40; 129.7; 132.9; 137.7; 137.8; 138.12; 138.15; 138.19; 138.82:
‡
‡
HR-MS: 1023.4271 (C62H64NaO12 , [M ‡ Na] ; calc. 1023.4295).
Methyl 6-O-(2-O-Benzoyl-3,4,6-tri-O-benzyl-b-d-galactopyranosyl)-2,3,4-tri-O-benzyl-a-d-glucopyrano-
side (46). According to GP (TfOH), for 2.5 h. Yield 93%. White crystals. M.p. 133 ± 1358. [a]2D2 ˆ ‡23.3 (c ˆ
1.0, CHCl3). IR (KBr): 1720, 1265, 1111, 1065, 741, 702. 1H-NMR (500 MHz, CDCl3): 3.14 (s, 3 H); 3.35 (dd, J ˆ
9.7, 9.2, 1 H); 3.40 (dd, J ˆ 9.5, 2.6, 1 H); 3.55 ± 3.69 (m, 6 H); 3.86 (dd, J ˆ 9.5, 9.2, 1 H); 3.98 ± 4.00 (m, 1 H);
4.07 ± 4.12 (m, 1 H); 4.34 (d, J ˆ 11.0, 1 H); 4.38 ± 4.51 (m, 5 H); 4.42 (d, J ˆ 2.6, 1 H); 4.54 ± 4.72 (m, 5 H,
including HÀC(1')); 4.80 (d, J ˆ 11.0, 1 H); 4.96 (d, J ˆ 11.6, 1 H); 5.71 (dd, J ˆ 10.1, 7.6, HÀC(2')); 7.02 ± 7.40
(m, 32 H); 7.46 (dd, J ˆ 7.4, 7.4, 1 H); 7.94 (d, J ˆ 7.4, 2 H). 13C-NMR (CDCl3): 54.8; 67.6; 68.4; 69.4; 71.6; 72.4;
73.2; 73.4; 73.6; 74.4; 74.5; 75.4; 77.4; 79.7; 79.8; 81.8; 97.6; 101.6; 127.3; 127.4; 127.5; 127.6; 127.70; 127.75; 127.83;
128.0; 128.1; 128.2; 128.3; 128.4; 129.7; 130.0; 132.7; 137.5; 137.7; 138.1; 138.2; 138.4; 138.8; 165.0. HR-MS:
‡
‡
1023.4303 (C62H64NaO12 , [M ‡ Na] ; calc. 1023.4295).
Methyl 3-O-(2-O-Benzoyl-3,4,6-tri-O-benzyl-b-d-glucopyranosyl)-2,4,6-tri-O-benzyl-a-d-glucopyranoside
(47). According to GP (TfOH), for 6 h. Yield 87%. Colorless oil. [a]2D0 ˆ ‡26.5 (c ˆ 0.89, CHCl3). IR (KBr):
1728, 1458, 1365, 1265, 1095, 741, 702. 1H-NMR (500 MHz, CDCl3): 3.25 (s, 3 H); 3.30 (dd, J ˆ 9.5, 3.1, 1 H); 3.51
(dd, J ˆ 9.8, 8.9, 1 H); 3.54 ± 3.68 (m, 4 H); 3.71 (dd, J ˆ 11.0, 4.3, 1 H); 3.76 ± 3.82 (m, 1 H); 3.86 (dd, J ˆ 8.9, 8.5,
1 H); 3.87 ± 3.92 (m, 1 H); 4.24 (d, J ˆ 12.2, 1 H); 4.34 (d, J ˆ 3.1, 1 H); 4.35 (dd, J ˆ 9.5, 8.9, 1 H); 4.43 (d, J ˆ
12.2, 1 H); 4.45 ± 4.55 (m, 4 H); 4.58 (d, J ˆ 12.2, 1 H); 4.63 (d, J ˆ 10.7, 1 H); 4.70 (d, J ˆ 11.0, 1 H); 4.79 (d, J ˆ
11.0, 1 H); 4.82 (d, J ˆ 10.7, 1 H); 5.13 (d, J ˆ 11.0, 1 H); 5.21 (d, J ˆ 7.9, HÀC(1')); 5.40 (dd, J ˆ 8.9, 7.9, 1 H);
7.08 ± 7.18 (m, 10 H); 7.18 ± 7.32 (m, 20 H); 7.37 (dd, J ˆ 7.6, 7.6, 2 H); 7.53 (dd, J ˆ 7.6, 7.6, 1 H); 7.99 (d, J ˆ 7.6,
2 H). 13C-NMR (CDCl3): 54.9; 68.5; 68.7; 69.6; 73.4; 74.6; 74.9; 75.0; 75.1; 75.2; 75.7; 78.0; 78.4; 80.9; 83.1; 97.6;
100.1; 127.3; 127.5; 127.6; 127.77; 127.83; 127.9; 128.0; 128.18; 128.21; 128.29; 128.32; 128.34; 128.38; 129.7; 130.0;
‡
‡
137.84; 137.88; 137.94; 138.0; 138.4; 138.7; 165.2. HR-MS: 1023.4284 (C62H64NaO12
1023.4295).
,
[M ‡ Na] ; calc.
Methyl 3-O-(2-O-Benzoyl-3,4,6-tri-O-benzyl-b-d-galactopyranosyl)-2,4,6-tri-O-benzyl-a-d-glucopyrano-
side (48). According to GP (TfOH), for 9 h. Yield 87%. Colorless oil. [a]2D3 ˆ ‡19.9 (c ˆ 1.0, CHCl3). IR
(neat): 2870, 1728, 1597, 1496, 1458, 1103, 748, 701. 1H-NMR (400 MHz, CDCl3): 3.26 (s, 3 H); 3.28 (dd, J ˆ 9.7,
3.4, 1 H); 3.44 ± 3.54 (m, 2 H); 3.55 ± 3.75 (m, 6 H); 4.08 ± 4.20 (m, 3 H); 4.24 ± 4.38 (m,4 H); 4.41 (d, J ˆ 12.0,
1 H); 4.46 (d, J ˆ 12.2, 1 H); 4.53 (d, J ˆ 12.4, 1 H); 4.58 (d, J ˆ 11.7, 1 H); 4.61 (d, J ˆ 11.2, 1 H); 4.69 (d, J ˆ
12.4, 1 H); 5.02 ± 5.15 (m, 2 H); 5.09 (d, J ˆ 8.0, HÀC(1')); 5.76 (dd, J ˆ 10.0, 8.0, 1 H); 6.90 ± 7.60 (m, 33 H);
8.02 (d, J ˆ 7.6, 2 H). 13C-NMR (CDCl3): 14.1; 21.0; 54.8; 60.3; 67.7; 68.3; 69.5; 71.4; 72.6; 72.9; 73.5; 73.6; 74.8;
75.1; 75.4; 77.7; 79.9; 80.5; 97.8; 100.8; 127.2; 127.3; 127.5; 127.6; 127.7; 127.84; 127.86; 127.88; 128.0; 128.1; 128.21;
128.26; 128.30; 128.32; 128.9; 129.8; 130.1; 132.9; 137.7; 137.8; 137.9; 138.0; 138.2; 138.7; 165.3. HR-MS:
‡
‡
1023.4303 (C62H64NaO12 , [M ‡ Na] ; calc. 1023.4295).
Methyl 4-O-(2-O-Benzoyl-3,4,6-tri-O-benzyl-b-d-glucopyranosyl)-2,3,6-tri-O-benzyl-a-d-glucopyranoside
(49). According to GP (TfOH), for 18 h. Yield 67%. White crystals. M.p. 124 ± 1278. [a]1D7 ˆ ‡26.1 (c ˆ 1.0,
1
CHCl3). IR (KBr): 1720, 1273, 1103, 1049, 740, 701. H-NMR (500 MHz, CDCl3): 3.25 (s, 3 H); 3.37 (dd, J ˆ
10.7, 1.8, 1 H); 3.39 ± 3.43 (m, 2 H); 3.48 ± 3.55 (m, 2 H); 3.60 (dd, J ˆ 9.5, 9.2, 1 H); 3.57 ± 3.64 (m, 1 H); 3.69
(dd, J ˆ 11.0, 1.8, 1 H); 3.73 (dd, J ˆ 9.5, 9.2, 1 H); 3.83 ± 3.92 (m, 2 H); 4.27 (d, J ˆ 12.2, 1 H); 4.37 (d, J ˆ 12.2,
1 H); 4.48 (d, J ˆ 9.2, 1 H); 4.51 (d, J ˆ 3.5, 1 H); 4.51 ± 4.59 (m, 3 H); 4.62 (d, J ˆ 12.2, 1 H); 4.65 (d, J ˆ 7.9,
HÀC(1')); 4.70 (d, J ˆ 11.3, 1 H); 4.73 (d, J ˆ 12.2, 1 H); 4.787 (d, J ˆ 11.0, 1 H); 4.793 (d, J ˆ 11.3, 1 H); 5.08
(d, J ˆ 11.3, 1 H); 5.23 (dd, J ˆ 9.5, 7.9, 1 H); 7.05 ± 7.15 (m, 5 H); 7.18 ± 7.34 (m, 22 H); 7.32 ± 7.43 (m, 5 H); 7.53 ±
7.57 (m, 1 H); 7.88 (dd, J ˆ 8.5, 1.5, 2 H). 13C-NMR (CDCl3): 55.2; 67.8; 68.7; 69.5; 73.38; 73.47; 73.50; 74.2; 74.8;
75.0; 75.2; 75.4; 78.1; 78.9; 80.2; 82.8; 98.3; 100.3; 127.0; 127.3; 127.5; 127.6; 127.67; 127.70; 127.81; 127.84; 127.90;
127.98; 128.03; 128.06; 128.18; 128.23; 128.27; 128.34; 128.38; 128.5; 129.7; 129.8; 133.1; 137.7; 137.9; 138.0; 138.3;
‡
‡
138.4; 139.6; 164.8. HR-MS: 1023.4271 (C62H64NaO12 , [M ‡ Na] ; calc. 1023.4295).
Methyl 4-O-(2-O-Benzoyl-3,4,6-tri-O-benzyl-b-d-galactopyranosyl)-2,3,6-tri-O-benzyl-a-d-glucopyrano-
side (50). According to GP (TfOH), for 12 h. Yield 70%. White solid. M.p. 118 ± 1218. [a]2D2 ˆ ‡32.0 (c ˆ 1.0,
1
CHCl3). IR (KBr): 2916, 2877, 1728, 1458, 1365, 1265, 1095, 1049, 741, 702. H-NMR (400 MHz, CDCl3): 3.25
(s, 3 H); 3.32 ± 3.56 (m, 7 H); 3.59 (dd, J ˆ 10.7, 3.2, 1 H); 3.78 ± 3.90 (m, 2 H); 3.96 ± 4.04 (m, 1 H); 4.22 (d, J ˆ

Helvetica Chimica Acta ± Vol. 83 (2000)
1917
12.2, 1 H); 4.23 (d, J ˆ 11.7, 1 H); 4.34 (d, J ˆ 11.7, 1 H); 4.41 (d, J ˆ 12.4, 1 H); 4.50 (d, J ˆ 3.6, 1 H); 4.54 (d, J ˆ
7.8, HÀC(1')); 4.50 ± 4.70 (m, 4 H); 4.72 ± 4.84 (m, 2 H); 4.96 ± 5.10 (m, 2 H); 5.60 (dd, J ˆ 10.0, 7.8, 1 H); 7.00 ±
7.50 (m, 32 H); 7.51 ± 7.80 (m, 1 H); 7.89 (d, J ˆ 8.3, 2 H). 13C-NMR (CDCl3): 55.2; 67.8; 68.0; 69.5; 71.2; 72.4;
72.5; 73.27; 73.33; 73.4; 73.5; 74.6; 75.3; 76.5; 78.8; 79.9; 98.3; 100.6; 126.9; 127.40; 127.44; 127.5; 127.65; 127.68;
127.75; 127.84; 127.89; 127.91; 128.0; 128.1; 128.22; 128.26; 128.29; 128.31; 128.35; 129.8; 129.9; 132.9; 137.7;
‡
‡
138.0; 138.4; 138.7; 139.5; 164.9. HR-MS: 1023.4301 (C62H64NaO12, [M ‡ Na] ; calc. 1023.4295).
Ethyl 2,3,4-Tri-O-benzoyl-6-O-(2-O-benzoyl-3,4,6-tri-O-benzyl-b-d-glucopyranosyl)-1-thio-b-d-glucopyra-
noside (51). According to GP (TfOH), for 5 h. Yield 85%. Colorless foam. [a]2D1 ˆ 26.2 (c ˆ 1.0, CHCl3). IR
(KBr): 1728, 1265, 1095, 709. 1H-NMR (500 MHz, CDCl3): 1.04 (t, J ˆ 7.3, 3 H); 2.42 (dq, J ˆ 12.5, 7.3, 1 H); 2.52
(dq, J ˆ 12.5, 7.3, 1 H); 3.48 ± 3.54 (m, 1 H); 3.65 ± 3.80 (m, 4 H); 3.81 (dd, J ˆ 9.2, 8.9, 1 H); 3.93 ± 3.98 (m, 1 H);
4.01 (dd, J ˆ 11.6, 1.5, 1 H); 4.44 (d, J ˆ 12.2, 1 H); 4.52 ± 4.57 (m, 2 H); 4.62 (d, J ˆ 9.8, 1 H); 4.65 (d, J ˆ 11.0,
1 H); 4.67 (d, J ˆ 8.2, HÀC(1')); 4.73 (d, J ˆ 11.0, 1 H); 4.79 (d, J ˆ 11.0, 1 H); 5.28 (dd, J ˆ 8.9, 8.2, 1 H); 5.33
(dd, J ˆ 9.8, 9.5, 1 H); 5.39 (dd, J ˆ 9.8, 9.5, 1 H); 5.79 (dd, J ˆ 9.5, 9.5, 1 H); 7.18 ± 7.50 (m, 26 H); 7.52 ± 7.58
(m, 1 H); 7.75 (dd, J ˆ 7.3, 1.5, 2 H); 7.86 (dd, J ˆ 8.2, 1.2, 2 H); 7.91 (dd, J ˆ 8.5, 1.5, 2 H); 8.06 (dd, J ˆ 8.6, 1.5,
2 H). 13C-NMR (CDCl3): 14.7; 23.8; 60.3; 68.0; 68.4; 69.5; 70.5; 73.4; 73.6; 74.0; 74.9; 75.06; 75.15; 77.7; 78.2;
82.8; 83.2; 101.0; 127.6; 127.7; 127.9; 128.17; 128.25; 128.30; 128.35; 128.6; 128.8; 129.1; 129.6; 129.8; 129.9; 133.0;
‡
‡
133.1; 133.2; 133.4; 137.7; 137.8; 137.9; 165.0; 165.1; 165.3; 165.6. HR-MS: 1095.3625 (C63H60NaO14S , [M ‡ Na] ;
calc. 1095.3601).
Ethyl
2,3,4-Tri-O-benzoyl-6-O-(2-O-benzoyl-3,4,6-tri-O-benzyl-b-d-galactopyranosyl)-1-thio-b-d-gluco-
pyranoside (52). According to GP (TfOH), for 1.5 h. Yield 81%. Colorless foam. [a]2D4 ˆ ‡12.9 (c ˆ 1.0,
CHCl3). IR (KBr): 1728, 1265, 1095, 710. 1H-NMR (500 MHz, CDCl3): 0.97 (t, J ˆ 7.3, 3 H); 2.35 (dq, J ˆ 12.5,
7.3, 1 H); 2.45 (dq, J ˆ 12.5, 7.3, 1 H); 3.46 ± 3.60 (m, 3 H); 3.62 (dd, J ˆ 10.1, 2.8, 1 H); 3.71 (dd, J ˆ 11.6, 7.6,
1 H); 3.90 ± 4.05 (m, 3 H); 4.30 (d, J ˆ 11.9, 1 H); 4.33 (d, J ˆ 11.9, 1 H); 4.44 (d, J ˆ 12.2, 1 H); 4.55 ± 4.68
(m, 4 H, including HÀC(1')); 4.94 (d, J ˆ 11.6, 1 H); 5.30 (dd, J ˆ 9.8, 9.8, 1 H); 5.37 (dd, J ˆ 9.8, 9.5, 1 H); 5.65
(dd, J ˆ 10.1, 7.9, HÀC(2')); 5.78 (dd, J ˆ 9.5, 9.5, 1 H); 7.20 ± 7.60 (m, 27 H); 7.75 (d, J ˆ 7.6, 2 H); 7.83 (d, J ˆ 7.3,
2 H); 7.90 (d, J ˆ 7.3, 2 H); 8.05 (d, J ˆ 7.6, 2 H). 13C-NMR (CDCl3): 14.6; 23.9; 53.4; 67.9; 68.3; 69.5; 70.6; 71.6;
71.7; 72.2; 73.5; 74.1; 74.4; 78.1; 79.9; 83.1; 101.2; 127.5; 127.6; 127.75; 127.82; 128.1; 128.20; 128.23; 128.26; 128.4;
128.6; 128.8; 129.1; 129.6; 129.7; 129.8; 130.1; 132.9; 133.0; 133.1; 133.3; 137.5; 137.7; 138.3; 165.0; 165.2; 165.3;
‡
‡
165.6. HR-MS: 1095.3586 (C63H60NaO14S , [M ‡ Na] ; calc. 1095.3601).
Ethyl 3-O-Acetyl-6-O-(2-O-benzoyl-3,4,6-tri-O-benzyl-b-d-glucopyranosyl)-4-O-benzyl-2-deoxy-2-phthal-
imido-1-thio-b-d-glucopyranoside (53). According to GP (TfOH), for 8 h. Yield 81%. White crystals. M.p.
157 ± 1608. [a]2D1 ˆ ‡17.6 (c ˆ 1.2, CHCl3). IR (KBr): 1720, 1381, 1265, 1227, 1095, 710. 1H-NMR (500 MHz,
CDCl3): 1.08 (t, J ˆ 7.3, 3 H); 1.67 (s, 3 H); 2.46 (dq, J ˆ 12.5, 7.3, 1 H); 2.58 (dq, J ˆ 12.5, 7.3, 1 H); 3.55 ± 3.62
(m, 1 H); 3.66 (dd, J ˆ 10.1, 8.2, 1 H); 3.67 ± 3.73 (m, 1 H); 3.75 ± 3.86 (m, 5 H); 4.17 (dd, J ˆ 11.0, 1.2, 1 H); 4.23
(dd, J ˆ 10.4, 10.0, 1 H); 4.37 (d, J ˆ 11.3, 1 H); 4.47 (d, J ˆ 11.3, 1 H); 4.598 (d, J ˆ 12.2, 1 H); 4.600 (d, J ˆ 10.4,
1 H); 4.65 (d, J ˆ 7.9, HÀC(1')); 4.68 (d, J ˆ 10.7, 1 H); 4.69 (d, J ˆ 12.2, 1 H); 4.75 (d, J ˆ 11.0, 1 H); 4.82 (d, J ˆ
10.7, 1 H); 5.37 (dd, J ˆ 9.2, 7.9, 1 H); 5.40 (d, J ˆ 10.4, 1 H); 5.74 (dd, J ˆ 10.0, 8.2, 1 H); 7.04 ± 7.43 (m, 22 H);
7.50 ± 7.55 (m, 1 H); 7.67 ± 7.74 (m, 2 H); 7.78 ± 7.85 (m, 2 H); 8.02 (dd, J ˆ 8.2, 1.2, 2 H). 13C-NMR (CDCl3): 14.9;
20.4; 23.8; 54.1; 67.9; 68.7; 73.6; 73.8; 73.9; 74.4; 74.96; 74.99; 75.3; 76.6; 78.0; 78.6; 80.4; 82.8; 101.1; 123.4; 123.5;
127.3; 127.6; 127.8; 127.9; 128.20; 128.26; 128.34; 128.4; 129.7; 131.2; 131.7; 133.0; 134.0; 134.2; 137.75; 137.78;
‡
‡
138.1; 165.0; 167.4; 167.6; 169.9. HR-MS: 1044.3619 (C59H59NNaO13S , [M ‡ Na] ; calc. 1044.3605).
Ethyl 3-O-Acetyl-6-O-(2-O-benzoyl-3,4,6-tri-O-benzyl-b-d-galactopyranosyl)-4-O-benzyl-2-deoxy-2-phthal-
imido-1-thio-b-d-glucopyranoside (54). According to GP (TfOH), for 3.5 h. Yield 71%. Colorless oil. [a]D22
ˆ
‡11.8 (c ˆ 1.0, CHCl3). IR (KBr): 1720, 1381, 1095, 748, 710. 1H-NMR (500 MHz, CDCl3): 1.03 (t, J ˆ 7.3, 3 H);
1.67 (s, 3 H); 2.40 (dq, J ˆ 12.5, 7.3, 1 H); 2.55 (dq, J ˆ 12.5, 7.3, 1 H); 3.56 ± 3.72 (m, 6 H); 3.75 (dd, J ˆ 11.2, 4.9,
1 H); 4.02 ± 4.05 (m, 1 H); 4.14 ± 4.18 (m, 1 H); 4.20 (dd, J ˆ 10.4, 10.4, 1 H); 4.37 (d, J ˆ 9.6, 1 H); 4.40 ± 4.52
(m, 4 H); 4.60 (d, J ˆ 8.0, HÀC(1')); 4.62 ± 4.68 (m, 2 H); 5.00 (d, J ˆ 11.6, 1 H); 5.37 (d, J ˆ 10.4, 1 H); 5.66 ±
5.74 (m, 2 H); 7.00 ± 7.10 (m, 2 H); 7.10 ± 7.45 (m, 20 H); 7.54 (dd, J ˆ 7.3, 7.3, 1 H); 7.57 ± 7.62 (m, 2 H); 7.75 ± 7.85
(m, 2 H); 8.02 (d, J ˆ 7.3, 2 H). 13C-NMR (CDCl3): 14.7; 20.4; 23.6; 54.0; 67.6; 68.4; 71.6; 71.7; 72.3; 73.5; 73.6;
73.9; 74.3; 74.4; 76.5; 78.5; 79.9; 80.2; 101.4; 123.4; 123.5; 127.4; 127.5; 127.6; 127.8; 127.9; 128.16; 128.18; 128.22;
128.26; 128.4; 129.8; 130.1; 131.7; 132.8; 133.9; 134.2; 137.5; 137.8; 138.4; 165.1; 167.3; 167.5; 169.9. HR-MS:
‡
‡
1044.3602 (C59H59NNaO13S , [M ‡ Na] ; calc. 1044.3605).

1918
Helvetica Chimica Acta ± Vol. 83 (2000)
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Received May 2, 2000