Ionic liquid [bmim]PF6-mediated synthesis of 1,2-orthoesters of carbohydrates and the glycosidation reactions of 4-pentenyl orthoesters

Article abstract of DOI:10.1246/bcsj.80.553

A facile synthesis of the 1,2-orthoesters of carbohydrates in the ionic liquid [bmim]PF₆ without a quaternary ammonium salt like tetrabutylammonium iodide, is described. The glycosidation reactions of 4-pentenyl orthoesters (NPOEs) with differe

Full text of DOI:10.1246/bcsj.80.553

Ó 2007 The Chemical Society of Japan
Bull. Chem. Soc. Jpn. Vol. 80, No. 3, 553–560 (2007)
553
Ionic Liquid [bmim]PF6-Mediated Synthesis of 1,2-Orthoesters
of Carbohydrates and the Glycosidation Reactions
of 4-Pentenyl Orthoesters
Saithalavi Anas, Valiyaveetil Sanjayan Sajisha, Rani Rajan,
ꢀ
Rajasekaran Thirumalai Kumaran, and Kokkuvayil Vasu Radhakrishnan
Organic Chemistry Section, Chemical Sciences and Technology Division,
Regional Research Laboratory (CSIR), Trivandrum 695 019, India
Received July 31, 2006; E-mail: radhupreethi@rediffmail.com
A facile synthesis of the 1,2-orthoesters of carbohydrates in the ionic liquid [bmim]PF6 without a quaternary
ammonium salt like tetrabutylammonium iodide, is described. The glycosidation reactions of 4-pentenyl orthoesters
(NPOEs) with different alcohols are also discussed. The work described in this paper showed that [bmim]PF6 is an ef-
ficient and recyclable solvent for the synthesis and glycosidation reaction of orthoesters.
In recent years, ionic liquids have been described as one of
the most promising environmentally benign reaction media in
..
OBn
O
O
O
O
BnO
BnO
H
O
organic synthesis.1 They have several benefits over conven-
tional organic solvents and show better process performance
in reactions.2 Ionic liquids possess fundamentally unique com-
binations of properties, such as being non-volatile and able to
dissolve both ionic and non-ionic species. Room temperature
ionic liquids are being applied to a wide range of syntheses
and their usefulness in a number of reactions, both catalytic
and stoichiometric, have been demonstrated recently.3 How-
ever, there is little understanding of how the ionic liquids
might affect reactivity when used as a reaction medium.
Due to their high polarity, ionic liquids can coordinate with
polar molecules very easily, thereby solubilizing the organic
compounds. Among polar organic molecules, carbohydrates
have gained much attention.4 The current developments and
trends in glycobiology5 stress the prime importance of carbo-
hydrate chemistry. One of the major challenges for carbohy-
drate chemists is to avoid the environmental problems caused
by the extensive use of the solvents, such as DMF, pyridine,
MeOH, etc. It is, therefore, of great interest to develop practi-
cal and environmentally benign methods for synthetic carbo-
hydrate chemistry, especially for glycosidation, which is one
of the most important and fundamental transformation involv-
ing carbohydrates. There are only few reports in the literature,
that describe the use of ionic liquid as solvent in carbohydrate
chemistry. Ionic liquids have been used for the acetylation of
sugars6 and for the synthesis of various glycosides and disac-
charides from trichloroacetimidate donors.7 Toshima et al.
have reported the glycosidation of glucopyranosyl phosphates
and glycosyl fluorides in ionic liquid.8 Very recently, Poletti et
al. have studied the influence of the reaction medium on the
stereochemical outcome of the glycosylation with trichloro-
acetimidate donors in ionic liquids.9
+
O
+
O
O
R1
O
R1
R1
OR
trioxolenium ion
dioxolenium ion
Soft Nu-
Hard Nu-
OBn
O
O
O
BnO
BnO
Nu
Nu
R1
OCOR1
O
Orthoester
1,2-trans glycoside
Scheme 1.
much attention. This interest is based on the fact that ortho-
esters typically undergo facile acid-catalyzed rearrangement,
in which the alkoxy group is transferred to the anomeric
centre, resulting in the formation of the glycosidic products
(Scheme 1).11
The interesting reactivity of NPOEs have been well utilized
in the pioneering works of Fraser-Reid and co-workers in
synthesizing oligosaccharides of biological importance.12 For
example, NPOEs have been used for the preparation of the
oligosaccharide portion of the viral coat of HIV1, known as
GP-120,13 and in the preparation of glycolipids for multivalent
presentation (Fig. 1).14 Synthesis of lipoarabinomannan com-
ponent of the cell wall of Mycobacterium tuberculosis using
NPOE donors have also been achieved by Fraser-Reid et
al.15 Very recently, Seeberger et al. have explored the utility
of 1,2-orthoesters as important precursors for the synthesis
of glycosylphosphates (Scheme 2).16
As part of our program on the synthesis of neoglycoconju-
gates for pharmaceutical applications, we have been interested
in utilizing 1,2-orthoesters of carbohydrates as monomers for
oligosaccharide synthesis. In this context, we have previously
reported a facile method for the synthesis of 1,2-orthoesters of
carbohydrates in [bmim]PF6 without quaternary ammonium
1,2-Orthoesters are valuable intermediates in synthetic car-
bohydrate chemistry.10 Among various 1,2-orthoesters of car-
bohydrates, 4-pentenyl orthoesters (NPOEs) have received
Published on the web March 13, 2007; doi:10.1246/bcsj.80.553

554 Bull. Chem. Soc. Jpn. Vol. 80, No. 3 (2007)
Ionic Liquid-Mediated Synthesis
H
N
Protein
O
P
O
O
OH
OH
OH
O
OR
O
O
HO
GPI Anchor of Plasmodium
falciparum (malarial parasite)
HO
O
P
HO
HO
H N
2
O
O
O
OH
O
O
HO
HO
O
OH
HO
HO
OH
O
O
O
OH
O
HO
HO
HO
HO
OH
O
O
O
O
C
H
15 31
O
C
n
HO
O
H
OCOMYR
OH
Glycolipids for multivalent
presentation
15 31
HO
NH
O
2
O
O
O
OH
O
O
Fatty
Fatty
P
O
O
OH
Fig. 1. Some NPOE derived oligosaccharides.
Table 1. Synthesis of 1,2-Orthoesters of Glucose in Ionic
Liquid
OBn
OAc
O
OMe
O
OBn
O
HOPO (OBu)2
CH2Cl2
BnO
BnO
O
BnO
BnO
Entry
Alcohol (R–OH)
Yield/%
O
P
O
OBu
OBu
OH
1
2
3
2a
80a)
64a)
58a)
OH
OH
2b
2c
Scheme 2.
OBz
OBz
4
5
6
7
1-Butanol
Propan-2-ol
Isooctyl alcohol
Benzyl alcohol
2d
2e
2f
60a)
52b)
77b)
59a)
O
R-OH
O
BzO
BzO
BzO
BzO
2,6-Lutidine
[bmim]PF6
O
OBz
2g
O
Br
Ph
2a-g
1
OR
a) Alcohol (1.5 equiv), 2,6-lutidine (2 equiv), [bmim]PF6, rt,
8 h. b) Alcohol (1.5 equiv), 2,6-lutidine (2 equiv), [bmim]PF6,
45 ꢁC, 3 h.
Scheme 3.
salts as promoters.17 The details of this work and the glycosi-
dation reactions of NPOEs in ionic liquid are presented in this
paper. To the best of our knowledge this is the first report on
the glycosidation of NPOEs in an ionic liquid.
uid was washed with water, followed by ether, dried in vacuo
and reused. Similar results were obtained with various other al-
cohols, and the results obtained with glucopyranosyl bromide
are summarized in Table 1.
Results and Discussion
To establish the feasibility of this reaction as a general
method for the synthesis of 1,2-orthoesters, we prepared galac-
tose, mannose, and lactose orthoesters in the ionic liquid, and
the results are summarized in Table 2. The reaction proceeded
smoothly without any quaternary ammonium salt as promoter,
and it was complete in 8 h at room temperature. At 45 ꢁC, it
took only 3 h for completion. However, in the case of lactosyl
bromide, the reactions took 8 h at 45 ꢁC for completion. The
reaction time was found to be considerably reduced even in
the absence of quaternary ammonium salts. This shows that
the ionic liquid has the ability to enhance the reaction rate
without affecting the yield of the reaction. In some cases, it
was found that the yields were better than those obtained from
the existing methods. It is noteworthy that the ionic liquid can
be reused several times, and purification of the product is also
easier.
Glycosidation Reactions in Ionic Liquid, [bmim]PF6.
Though trichloroacetimidate,7 glycosyl phosphates,8 and fluo-
rides9 have been utilized in glycosidation reactions in ionic liq-
uids, to the best of our knowledge, there is no report on the use
of ionic liquid as a solvent for NPOE-mediated glycosidations.
Owing to the increased attention towards NPOEs11–15 in oligo-
saccharide synthesis and our sustained interest in using NPOEs
Synthesis of 1,2-Orthoesters in [bmim]PF6. The classical
method for the preparation of orthoesters involves refluxing
the anomeric bromide in dry dichloromethane with a base-like
2,6-lutidine for five days.18 The modified method using tetra-
butylammonium iodide also requires refluxing the bromide
in dry dichloromethane for 24 h. Other methods available for
the synthesis of 1,2-orthoesters include the treatment of per-
acetylated or perbenzoylated glycosyl bromides with quaterna-
ry ammonium salts19 or silver triflate20 and a base or with al-
cohol and potassium fluoride.21 The reaction of 1-hydroxy sug-
ars with tetramethyl-ꢀ-chloroenamine and alcohol in presence
of triethylamine22 also results in the formation of orthoesters.
These methods suffer from some major drawbacks, like long
reaction time, need for dry solvents and cumbersome work-up.
Our studies began with the reaction of perbenzoylated
glucopyranosyl bromide with 4-penten-1-ol in presence of
2,6-lutidine in [bmim]PF6 without using tetrabutylammonium
iodide. The reaction proceeded smoothly at room temperature
(8 h) affording the glucose NPOE in 80% yield (Scheme 3).
The product was separated from the reaction mixture by ex-
traction with ether and purified by silica-gel column chroma-
tography (if needed). The water and ether insoluble ionic liq-

S. Anas et al.
Bull. Chem. Soc. Jpn. Vol. 80, No. 3 (2007)
555
Table 2. Synthesis of 1,2-Orthoesters of Galactose, Man-
nose, and Lactose in an Ionic Liquid
Table 3. Glycosidation of NPOEs with Various Alcohols in
Ionic Liquida)
BzO
O
BzO
O
R-OH
Entry
Donor
Acceptor (R–OH)
Yield/%
1
2
Isooctyl alcohol
2-Adamantanol
OH
10a
10b
79
71
2,6-Lutidine
[bmim]PF6
Br
O
OBn
O
O
OR
OBz
BnO
BnO
Ph
O
O
OPn
O
9
Ph
3
BnO
10c
62
Entry
Sugar bromide
Alcohol (R–OH)
Yield/%
BnO
BnO
OMe
1
2
4a
75a)
OBz
OBz
OH
O
68a)
69a)
82a)
OH
4b
4c
BzO
4
5
Isooctyl alcohol
Cyclohexanol
12a
12b
60
84
OBz
OBz
Br
3
4
Propan-2-ol
O
BzO
BzO
3
Isooctyl alcohol 4d
O
O
OPn
11
Ph
5
6
6a
70a)
90a)
59a)
53a)
35b)
OH
OBz
BzO
O
BzO
BzO
OH
6
7
8
OBn
BnO
Isooctyl alcohol
Cyclohexanol
2-Adamantanol
OH
14a
14b
14c
78
67
74
6b
OBn
O
7
8
9
Propan-2-ol
6c
Br
5
Isooctyl alcohol 6d
Benzyl alcohol 6e
O
O
OPn
Ph
O
BnO
9
14d
82
13
BnO
10
11
8a
80b)
49b)
20b)
43b)
BzO
BzO
OBz
O
OH
BnO
OMe
OBz
O
O
OH
8b
BzO
BzO
BzO
10
11
Isooctyl alcohol
Cyclohexanol
OH
16a
16b
72
66
Br
Ph
OPn
12
13
Propan-2-ol 8c
Isooctyl alcohol 8d
OBn
7
O
O
O
BnO
BnO
O
a) Alcohol (1.5 equiv), 2,6-lutidine (2 equiv), [bmim]PF6, rt,
8 h. b) Alcohol (1.5 equiv), 2,6-lutidine (2 equiv), [bmin]PF6,
45 ꢁC, 8 h.
12
BnO
16c
77
15
BnO
BnO
OMe
a) Reaction conditions: donor (2 equiv), acceptor (1 equiv),
NIS (2 equiv), Yb(OTf)3 (2 mol %), [bmim]PF6, rt, 10 min.
OBn
OBn
O
O
BnO
BnO
BnO
BnO
Table 4. Synthesis of NPOE of Mannose to Study the Reus-
a)
i
R-OH
+
OR
ability of [bmim]PF6
O
OBz
O
9
10a
OBz
Ph
O
BzO
BzO
BzO
Ph
OPn
O
OPn
O
BzO
BzO
BzO
O
OH
R = Isooctyl, Pn = 4-Pentenyl
+
i = NIS (2 equiv.), Yb(OTf)3 (2 mol %), [bmim] PF6, r.t., 10 min
Br
5
6a
Scheme 4.
Cycle
1
2
3
4
5
as glycoside donors, we decided to investigate its glycosida-
tion reactions in [bmim]PF6. Our preliminary experiments in-
volved the reaction of 3,4,6-tribenzyl-NPOE of glucose 9 with
isooctyl alcohol. The reaction afforded the corresponding ꢁ-
glycoside 10a in 79% yield (Scheme 4).
Yield/%
70
70
67
68
67
a) Reaction conditions: alcohol (1.5 equiv), 2,6-lutidine (2
equiv), [bmim]PF6, rt, 8 h.
To prove the generality of the method, we have carried
out the coupling reactions of mannose and galactose using
NPOE donors with various alcohols including carbohydrate
derived alcohol. Results of our investigations are summarized
in Table 3.
The configurations of the products were assigned on the
basis of the coupling pattern in the proton NMR data. In the
case of glucose and galactose-based donors, the ꢁ-glycosides
were formed exclusively, while the mannose orthoester gave
the corresponding ꢀ-glycosides. Thus, this method can be ef-
ficiently used in the synthesis of oligosaccharides. The recov-
ered ionic liquid was purified and reused for the above experi-
ments.
bility of [bmim]PF6 in the reactions described above. The re-
sults of our investigations in the case of NPOE synthesis and
glycosidation reactions are summarized in Tables 4 and 5 re-
spectively. The ionic liquid [bmim]PF6 was recovered and
reused for each cycle, and the isolated yield for each cycle
is shown in the tables. As is clear from the results, there is
no appreciable change in the yield of the products even after
the fifth cycle using the recovered ionic liquid. This clearly
establishes the reusability of [bmim]PF6.
Conclusion
In conclusion, we developed a facile and eco-friendly meth-
od for the synthesis of 1,2-orthoesters in ionic liquid. Our
method did not need quaternary ammonium salts, thus simpli-
fying the reaction. The ionic liquid used as a solvent could be
Studies on the Reusability of the Ionic Liquid [bmim]-
PF6. We have carried out experimental studies on the reusa-

556 Bull. Chem. Soc. Jpn. Vol. 80, No. 3 (2007)
Ionic Liquid-Mediated Synthesis
Table 5. Glycosidation Reactions to Study the Reusability
a)
579.82 (Mþ ꢂ C5H9O).
of [bmim]PF6
Data for 3,4,6-Tri-O-benzoylglucose Allyl Orthoester (2b):
Rf : 0.27 (25% EtOAc–Hexane). IR (Neat) ꢃmax 2351, 1722,
OBn
OBz
1547, 1511, 1264, 1099, 1022, 713 cmꢂ1 1H NMR (300 MHz,
.
OH
Ph
O
OPn
O
BnO
BnO
BnO
BnO
O
O
CDCl3) ꢂ 8.08–7.36 (m, 20H), 6.04 (d, 1H, J ¼ 5:3 Hz), 5.84–
5.81 (m, 1H), 5.79–5.74 (m, 2H), 5.48 (d, 1H, J ¼ 8:7 Hz), 5.31
(dd, 1H, J1 ¼ 4 Hz, J2 ¼ 9:9 Hz), 5.09 (d, 2H, J ¼ 10:4 Hz),
4.39 (d, 2H, J ¼ 3:3 Hz), 4.14 (dd, 1H, J1 ¼ 3:3 Hz, J2 ¼ 8:3
Hz), 3.83 (dd, 1H, J1 ¼ 6:3 Hz, J2 ¼ 7:4 Hz). 13C NMR (75 MHz,
CDCl3) ꢂ 165.8, 164.9, 164.4, 157.6, 136.4, 133.7, 132.9, 130.1,
128.5, 126.4, 120.1, 116.7, 97.5, 72.7, 70.6, 69.2, 68.5, 67.5,
64.0, 24.4. LR-FAB-MS: Calcd for C37H32O10: 636.20; Found:
579.82 (Mþ ꢂ C3H5O).
BnO
O
+
BnO
O
BnO
BnO
O
OMe
16c
BnO
BnO
15
BnO
OMe
Cycle
1
2
3
4
5
Yield/%
77
76
74
76
74
a) Reaction conditions: donor (2 equiv), acceptor (1 equiv),
NIS (2 equiv), Yb(OTf)3 (2 mol %), [bmim]PF6, rt, 10 min.
Data for 3,4,6-Tri-O-benzoylglucose 2-Propargyl Ortho-
ester (2c): Rf : 0.15 (25%, EtOAc–Hexane). IR (Neat) ꢃmax
reused several times. The reaction is faster and high yielding.
We also efficiently performed the glycosidation reactions of
NPOEs of carbohydrates in an ionic liquid. Thus, we proved
that [bmim]PF6 can be used as an efficient and recyclable
solvent for the synthesis and glycosidation of NPOEs. This
method can be applied to the synthesis of oligosaccharides
of biological importance.
2351, 1735, 1624, 1352, 1511, 1454, 1253, 881, 707, 517 cmꢂ1
.
1H NMR (300 MHz, CDCl3) ꢂ 8.00–7.32 (m, 20H), 5.99 (d, 1H,
J ¼ 5:3 Hz), 5.41 (d, 1H, J ¼ 8:7 Hz), 4.78 (d, 1H, J ¼ 1:9 Hz),
4.47 (dd, 1H, J1 ¼ 2:8 Hz, J2 ¼ 9:4 Hz), 4.30 (dd, 1H, J1 ¼ 4:8
Hz, J2 ¼ 12:0 Hz), 4.06 (m, 2H), 3.89 (s, 2H), 2.06 (s, 1H).
13C NMR (75 MHz, CDCl3) ꢂ 165.7, 165.0, 134.4, 134.2, 133.6,
132.9, 130.0, 129.9, 126.5, 121.1, 97.7, 79.2, 73.9, 72.1, 69.0,
68.4, 67.5, 63.9, 52.3. LR-FAB-MS: Calcd for C37H30O10:
634.18; Found: 579.82 (Mþ ꢂ C3H3O).
Experimental
General. All reactions were conducted in oven-dried glass-
ware. Solvents used for the experiments were distilled and dried
as specified. All other reagents were purchased from local suppli-
Data for 3,4,6-Tri-O-benzoylglucose Butyl Orthoester (2d):
Rf : 0.37 (25% EtOAc–Hexane). IR (Neat) ꢃmax 2351, 1728, 1624,
1451, 1553, 1259, 512 cmꢂ1. 1H NMR (300 MHz, CDCl3) ꢂ 8.18–
7.32 (m, 20H), 5.95 (d, 1H, J ¼ 5:2 Hz), 5.40 (d, 1H, J ¼ 8:7 Hz),
4.68 (m, 2H), 4.44 (dd, 1H, J1 ¼ 2:8 Hz, J2 ¼ 12:0 Hz), 4.29 (dd,
1H, J1 ¼ 4:8 Hz, J2 ¼ 12:1 Hz), 4.05 (dd, 1H, J1 ¼ 3:4 Hz, J2 ¼
8:3 Hz), 3.27–3.16 (m, 2H), 1.43–1.38 (m, 2H), 1.27–1.10 (m,
2H), 0.82–0.75 (m, 3H). 13C NMR (75 MHz, CDCl3) ꢂ 165.3,
164.8, 164.5, 133.6, 133.4, 132.8, 130.1, 129.9, 129.7, 129.6,
128.5, 128.4, 128.35, 128.3, 128.2, 126.4, 97.5, 72.1, 69.3, 68.6,
67.5, 64.0, 52.0, 31.5, 19.2, 13.8. LR-FAB-MS: Calcd for
C38H36O10: 652.23; Found: 579.81 (Mþ ꢂ C4H9O).
er. All reactions were monitored by TLC (Silica gel 60 F254
,
0.25 mm, Merck); visualization was done with UV, by developing
in iodine or by staining with McGill solution. Chromatography
was performed on a silica-gel column (100–200 mesh). NMR
spectra were recorded at 300 (1H) and 75 (13C) MHz respectively
on a Bruker Advance DPX-300 MHz. Chemical shifts are reported
in ꢂ (ppm) relative to TMS (1H) or CDCl3 (13C) as internal stand-
ards. IR spectra were recorded on a Bomem MB series FT-IR
spectrometer; absorptions are reported in cmꢂ1. Mass spectra were
recorded using JEOL JMS 600H mass spectrometer. Abbrevia-
tions used in 1H NMR are: s = singlet, t = triplet, d = doublet,
dd = doublet of a doublet, and m = multiplet.
Data for 3,4,6-Tri-O-benzoylglucose Isopropyl Orthoester
(2e): Rf : 0.29 (25% EtOAc–Hexane). IR (Neat) ꢃmax 2345,
1732, 1624, 1516, 1457, 1253, 1109, 805, 707 cmꢂ1 1H NMR
.
Typical Procedure for the Synthesis of 3,4,6-Tribenzoylglu-
cose Pentenyl Orthoester. 2,3,4,6-Tetra-O-benzoyl-ꢀ-D-gluco-
pyranosyl bromide (1) (0.20 g, 0.30 mmol) was dissolved in
[bmim]PF6 (2 mL). 2,6-Lutidine (0.07 mL, 0.60 mmol) was added
to the solution followed by 4-penten-1-ol (0.05 mL, 0.46 mmol).
The reaction mixture was stirred at room temperature for 8 h.
The reaction mixture was extracted with ether and dried over
Na2SO4 and the solvent was evaporated off completely. The crude
sample on purification by silica-gel column chromatography af-
forded pure 2a as a viscous liquid (0.16 g, 80%).
(300 MHz, CDCl3) ꢂ 8.01–7.14 (m, 20H), 6.00 (d, 1H, J ¼ 3:6
Hz), 5.66 (m, 1H), 5.39 (m, 1H), 4.68 (m, 1H), 4.42 (dd, 1H, J1 ¼
2:6 Hz, J2 ¼ 11:9 Hz), 4.27 (dd, 1H, J1 ¼ 4:8 Hz, J2 ¼ 12:0 Hz,),
4.03–3.98 (m, 1H), 3.61 (m, 1H), 1.02 (d, 3H, J ¼ 6:1 Hz), 0.95
(d, 3H, J ¼ 6:1 Hz). 13C NMR (75 MHz, CDCl3) ꢂ 165.8, 165.1,
164.5, 136.5, 136.3, 133.6, 133.4, 132.8, 130.0, 129.9, 129.7,
129.6, 129.5, 128.5, 128.4, 128.3, 128.2, 97.4, 69.3, 68.6, 67.4,
67.2, 63.9, 32.0, 29.7, 24.3, 23.2. LR-FAB-MS: Calcd for
C37H34O10: 638.22; Found: 579.82 (Mþ ꢂ C3H7O).
Data for 3,4,6-Tri-O-benzoylglucose Isooctyl Orthoester
Data for 3,4,6-Tri-O-benzoylglucose 4-Pentenyl Orthoester
(2a): Rf : 0.29 (25% EtOAc–Hexane). IR (Neat) ꢃmax 3070,
(2f):
2925, 2856, 2346, 1722, 1542, 1511, 1449, 1253, 1104, 707,
507 cmꢂ1 1H NMR (300 MHz, CDCl3) ꢂ 8.01–7.32 (m, 20H),
Rf : 0.39 (25% EtOAc–Hexane). IR (Neat) ꢃmax 2959,
2449, 1740, 1644, 1612, 1460, 1275, 1109, 976, 925, 708 cmꢂ1
.
.
1H NMR (300 MHz, CDCl3) ꢂ 8.06–7.24 (m, 20H), 6.01 (d, 1H,
J ¼ 5:2 Hz), 5.84–5.67 (m, 3H), 5.47 (d, 1H, J ¼ 8:7 Hz), 4.97
(d, 1H, J ¼ 1:5 Hz), 4.92 (d, 1H, J ¼ 1:3 Hz), 4.74 (dd, 1H,
J1 ¼ 3:4 Hz, J2 ¼ 7:2 Hz), 4.51 (dd, 1H, J1 ¼ 4:8 Hz, J2 ¼ 12:0
Hz), 4.14–4.10 (m, 1H), 3.37–3.29 (m, 2H), 2.09–2.01 (m, 2H),
1.62–1.57 (m, 2H). 13C NMR (75 MHz, CDCl3) ꢂ 165.7, 164.9,
164.4, 137.7, 135.5, 133.5, 133.3, 132.8, 129.9, 129.8, 129.7,
129.6, 129.5, 129.1, 129.0, 128.5, 128.3, 128.2, 128.1, 126.3,
121.2, 120.0, 115.0, 97.4, 72.1, 69.2, 68.5, 67.4, 63.9, 63.3,
30.1, 28.6. LR-FAB-MS: Calcd for C39H36O10: 664.23; Found:
5.93 (d, 1H, J ¼ 5:1 Hz), 4.66 (d, 2H, J ¼ 3:0 Hz), 4.43 (m,
1H), 4.28 (dd, 1H, J1 ¼ 4:7 Hz, J2 ¼ 12:0 Hz), 4.13 (m, 1H),
3.43 (d, 1H, J ¼ 4:1 Hz), 3.14–3.04 (m, 2H), 1.27–1.20 (m,
15H). 13C NMR (75 MHz, CDCl3) ꢂ 165.8, 165.0, 164.4, 135.6,
133.7, 132.8, 130.0, 129.6, 129.4, 129.0, 128.5, 126.3, 97.4,
72.1, 69.2, 68.5, 66.1, 63.9, 41.9, 39.3, 30.2, 28.8, 23.6, 23.3,
22.9, 14.1, 10.9. LR-FAB-MS: Calcd for C42H44O10: 708.29;
Found: 579.69 (Mþ ꢂ C8H17O).
Data for 3,4,6-Tri-O-benzoylglucose Benzyl Orthoester
(2g): Rf : 0.30 (25% EtOAc–Hexane). IR (Neat) ꢃmax 3063,

S. Anas et al.
Bull. Chem. Soc. Jpn. Vol. 80, No. 3 (2007)
557
2625, 2360, 1728, 1607, 1452, 1276, 1182, 1115, 1034, 987 cmꢂ1
.
(m, 20H), 5.75 (d, 1H, J ¼ 2:9 Hz), 5.71–5.60 (m, 1H), 5.02 (m,
1H), 4.94–4.82 (m, 1H), 4.49 (dd, 1H, J1 ¼ 3:2 Hz, J2 ¼ 11:9
Hz), 4.33 (dd, 1H, J1 ¼ 4:6 Hz, J2 ¼ 12:0 Hz), 4.07 (dd, 1H,
J1 ¼ 3:7 Hz, J2 ¼ 10:6 Hz), 3.48–3.45 (m, 2H), 3.43–3.35 (m,
1H), 2.06–2.01 (m, 2H), 1.64–1.55 (m, 2H), 1.28–1.16 (m, 2H).
13C NMR (75 MHz, CDCl3) ꢂ 165.9, 165.6, 165.1, 137.8, 136.6,
133.4, 133.3, 132.9, 130.1, 129.8, 129.7, 129.2, 128.9, 128.5,
128.4, 128.2, 128.1, 127.6, 127.0, 126.5, 122.8, 115.0, 97.9,
72.2, 71.1, 66.5, 65.3, 63.4, 63.1, 30.1, 29.7. LR-FAB-MS: Calcd
for C39H36O10: 664.23; Found: 579.82 (Mþ ꢂ C5H9O).
1H NMR (300 MHz, CDCl3) ꢂ 8.08–7.39 (m, 25H), 6.03 (d, 1H,
J ¼ 5:2 Hz), 5.49 (m, 1H), 4.78 (d, 2H, J ¼ 3:0 Hz), 4.66 (s, 2H),
4.53 (dd, 1H, J1 ¼ 9:3 Hz, J2 ¼ 12:1 Hz), 4.38 (dd, 1H, J1 ¼ 6:2
Hz, J2 ¼ 10:9 Hz), 4.17 (m, 1H). 13C NMR (75 MHz, CDCl3) ꢂ
165.8, 165.1, 164.5, 137.1, 135.2, 133.6, 132.9, 130.06, 129.9,
129.1, 128.4, 126.5, 121.4, 97.6, 72.2, 69.2, 68.5, 67.5, 66.4, 63.9.
LR-FAB-MS: Calcd for C41H34O10: 686.22; Found: 579.78
(Mþ ꢂ C7H7O).
Data for 3,4,6-Tri-O-benzoylgalactose 4-Pentenyl Ortho-
ester (4a):
2917, 1723, 1452, 1269, 1091, 708, 496 cmꢂ1
Rf : 0.37 (25% EtOAc–Hexane). IR (Neat) ꢃmax
1H NMR (300
Data for 3,4,6-Tri-O-benzoylmannose Allyl Orthoester
(6b): Rf : 0.32 (25% EtOAc–Hexane). IR (Neat) ꢃmax 2917,
2356, 1723, 1452, 508 cmꢂ1. 1H NMR (300 MHz, CDCl3) ꢂ 8.01–
7.25 (m, 20H), 5.86 (m, 1H), 5.78 (d, 1H, J ¼ 2:7 Hz), 5.65 (d,
2H, J ¼ 3:9 Hz), 5.04 (m, 1H), 4.51 (dd, 1H, J1 ¼ 3:2 Hz, J2 ¼
11:5 Hz), 4.35 (m, 2H), 4.12–4.08 (m, 1H), 3.90 (d, 2H, J ¼ 5:1
Hz), 3.45 (dd, 1H, J1 ¼ 6:4 Hz, J2 ¼ 13:9 Hz). 13C NMR (75
MHz, CDCl3) ꢂ 165.9, 133.8, 133.4, 133.3, 132.8, 130.1, 129.8,
129.75, 129.7, 129.4, 129.1, 128.9, 128.4, 128.3, 128.2, 126.6,
122.9, 116.8, 98.0, 83.9, 72.3, 71.0, 65.5, 63.1, 32.0, 29.7. LR-
FAB-MS: Calcd for C37H32O10: 636.20; Found: 579.82 (Mþ ꢂ
C3H5O).
.
MHz, CDCl3) ꢂ 8.10–7.21 (m, 20H), 6.19 (d, 1H, J ¼ 5:0 Hz),
5.92–5.75 (m, 2H), 5.74–5.69 (m, 1H), 5.54 (dd, 1H, J1 ¼ 4:2
Hz, J2 ¼ 5:9 Hz), 4.93 (m, 2H), 4.76 (m, 2H), 4.62–4.59 (m, 1H),
4.37 (dd, 1H, J1 ¼ 5:0 Hz, J2 ¼ 10:7 Hz), 3.40 (m, 2H), 1.63–1.57
(m, 2H), 1.27–1.24 (m, 2H). 13C NMR (75 MHz, CDCl3) ꢂ 165.5,
165.2, 137.9, 136.6, 133.5, 133.3, 133.1, 129.86, 129.8, 129.7,
129.5, 129.4, 129.1, 128.5, 128.5, 128.4, 128.35, 128.3, 126.0,
120.2, 114.9, 98.2, 73.7, 72.0, 70.1, 68.8, 66.5, 63.1, 62.3,
30.2, 29.7. LR-FAB-MS: Calcd for C39H36O10: 664.23; Found:
579.81 (Mþ ꢂ C5H9O).
Data for 3,4,6-Tri-O-benzoylgalactose Allyl Orthoester
(4b): Rf : 0.29 (25% EtOAc–Hexane). IR (Neat) ꢃmax 2917,
Data for 3,4,6-Tri-O-benzoylmannose Isopropyl Orthoester
(6c): Rf : 0.29 (25% EtOAc–Hexane). IR (Neat) ꢃmax 2917, 2849,
2366, 1721, 1452, 1263, 1086, 708 cmꢂ1
.
1H NMR (300 MHz,
2356, 1716, 1458, 1269, 1086 cmꢂ1. H NMR (300 MHz, CDCl3)
1
CDCl3) ꢂ 7.97–7.35 (m, 20H), 6.21 (d, 1H, J ¼ 5:0 Hz), 5.98–
5.96 (m, 1H), 5.92–5.80 (m, 2H), 5.56 (dd, 1H, J1 ¼ 4:3 Hz,
J2 ¼ 5:1 Hz), 5.12 (d, 2H, J ¼ 10:5 Hz), 4.79 (dd, 1H, J1 ¼ 7:1
Hz, J2 ¼ 12:3 Hz), 4.64–4.50 (m, 1H), 4.38 (dd, 1H, J1 ¼ 4:9
Hz, J2 ¼ 10:6 Hz), 3.93 (d, 2H, J ¼ 4:9 Hz). 13C NMR (75 MHz,
CDCl3) ꢂ 165.2, 164.9, 164.3, 136.3, 133.8, 133.5, 133.3, 133.1,
129.83, 129.8, 129.7, 129.6, 129.4, 129.1, 128.9, 128.5, 128.37,
128.3, 126.1, 125.9, 120.3, 116.7, 98.5, 98.2, 73.4, 70.1, 68.9,
66.5, 64.9, 62.35, 29.7. LR-FAB-MS: Calcd for C37H32O10:
636.20; Found: 579.80 (Mþ ꢂ C3H5O).
ꢂ 8.01–7.23 (m, 20H), 5.74 (d, 1H, J ¼ 3:0 Hz), 5.62 (dd, 1H,
J1 ¼ 3:6 Hz, J2 ¼ 10:0 Hz), 5.04 (t, 1H, J ¼ 3:4 Hz), 4.47 (dd,
1H, J1 ¼ 3:4 Hz, J2 ¼ 12:0 Hz), 4.31 (dd, 1H, J1 ¼ 4:8 Hz, J2 ¼
12:0 Hz), 4.09–4.01 (m, 2H), 3.73 (m, 1H), 1.07 (d, 3H, J ¼ 6:1
Hz), 1.03 (d, 3H, J ¼ 6:1 Hz). 13C NMR (75 MHz, CDCl3) ꢂ
165.8, 165.7, 165.0, 145.4, 137.3, 133.3, 133.2, 132.8, 130.1,
129.9, 129.8, 129.25, 129.2, 128.47, 128.4, 128.2, 128.1, 126.6,
124.3, 123.6, 123.0, 119.2, 97.9, 75.7, 72.4, 71.2, 67.3, 66.8,
63.3, 23.5, 23.4. LR-FAB-MS: Calcd for C37H34O10: 638.25;
Found: 579.81 (Mþ ꢂ C3H7O).
Data for 3,4,6-Tri-O-benzoylgalactose Isopropyl Orthoester
(4c): Rf : 0.30 (25% EtOAc–Hexane). IR (Neat) ꢃmax 2920, 1725,
Data for 3,4,6-Tri-O-benzoylmannose Isooctyl Orthoester
(6d): Rf : 0.39 (30% EtOAc–Hexane). IR (Neat) ꢃmax 3070,
2968, 2939, 2866, 1737, 1718, 1601, 1543, 1455, 1363, 1270,
1630, 1587, 1517, 1459, 1110, 808, 702 cmꢂ1 1H NMR (300
.
MHz, CDCl3) ꢂ 8.02–7.20 (m, 20H), 6.03 (d, 1H, J ¼ 5:0 Hz),
5.60–5.57 (m, 1H), 5.27 (m, 2H), 4.82 (dd, 1H, J1 ¼ 7:2 Hz, J2 ¼
12:4 Hz), 4.63–4.51 (m, 1H), 4.35 (dd, 1H, J ¼ 4:9, 10.8 Hz), 3.59
(m, 1H), 1.05 (d, 3H, J ¼ 6:1 Hz), 1.01 (d, 3H, J ¼ 6:1 Hz).
13C NMR (75 MHz, CDCl3) ꢂ 165.8, 165.7, 165.32, 136.6, 136.3,
136.0, 133.4, 132.8, 130.0, 129.9, 129.8, 129.7, 129.5, 128.9,
128.5, 128.4, 128.3, 128.2, 127.9, 98.8, 70.0, 68.9, 66.6, 65.1,
65.0, 62.6, 32.0, 29.7, 24.5, 23.3. LR-FAB-MS: Calcd for
C37H34O10: 638.22; Found: 579.78 (Mþ ꢂ C3H7O).
1178, 1095, 1022, 978, 891, 793, 764, 706 cmꢂ1 1H NMR (300
.
MHz, CDCl3) ꢂ 8.03–7.27 (m, 20H), 5.93 (t, 1H, J ¼ 10:2 Hz),
5.78 (d, 1H, J ¼ 2:6 Hz), 5.65 (dd, 1H, J1 ¼ 10:0 Hz, J2 ¼ 3:9
Hz), 5.04 (t, 1H, J ¼ 3:0 Hz), 4.50 (dd, 1H, J1 ¼ 12:1 Hz, J2 ¼
3:4 Hz), 4.35 (dd, 1H, J1 ¼ 12:1 Hz, J2 ¼ 6:0 Hz), 4.13–4.07 (m,
1H), 3.25–3.23 (m, 2H), 1.30–1.16 (m, 8H), 0.83–0.74 (m, 6H).
13C NMR (75 MHz, CDCl3) ꢂ 166.0, 165.9, 165.1, 136.7, 133.4,
133.3, 132.9, 130.1, 129.8, 129.7, 129.2, 129.1, 129.0, 128.4,
128.2, 128.1, 126.5, 122.8, 97.9, 76.0, 72.3, 71.2, 66.6, 66.1,
63.2, 39.6, 39.4, 31.5, 30.3, 29.7, 29.0, 28.9, 23.7, 23.6, 22.9,
14.1, 10.9, 10.8. LR-FAB-MS: Calcd for C42H44O10: 708.29;
Found: 731.43 ðM þ NaÞþ.
Data for 3,4,6-Tri-O-benzoylgalactose Isooctyl Orthoester
(4d): Rf : 0.16 (25% EtOAc–Hexane). IR (Neat) ꢃmax 2923,
1721, 1595, 1446, 1263, 1091, 1017, 771, 702 cmꢂ1 1H NMR
.
(300 MHz, CDCl3) ꢂ 8.10–7.21 (m, 20H), 6.08 (d, 1H, J ¼ 5:0
Hz), 5.83 (d, 1H, J ¼ 3:4 Hz), 5.64 (dd, 1H, J1 ¼ 3:5 Hz, J2 ¼
12:0 Hz), 4.90–4.87 (m, 1H), 4.63–4.59 (m, 2H), 4.35–4.32 (m,
1H), 3.62 (t, 2H, J ¼ 6:5 Hz), 1.40–0.86 (m, 15H). 13C NMR
(75 MHz, CDCl3) ꢂ 165.8, 165.5, 165.4, 136.9, 133.3, 133.1,
133.0, 130.0, 129.9, 129.9, 129.8, 129.7, 129.5, 129.4, 128.7,
128.6, 128.34, 128.2, 120.5, 117.5, 98.2, 90.7, 69.9, 69.6, 68.5,
66.5, 62.4, 42.3, 38.4, 29.8, 23.9, 14.2, 10.4. LR-FAB-MS: Calcd
for C42H44O10: 708.29; Found: 579.82 (Mþ ꢂ C8H17O).
Data for 3,4,6-Tri-O-benzoylmannose Benzyl Orthoester
(6e):
Rf : 0.39 (30% EtOAc–Hexane). IR (Neat) ꢃmax 3070,
2963, 1731, 1716, 1605, 1548, 1494, 1460, 1275, 1182, 1109,
1071, 1032, 978, 852, 798, 710 cmꢂ1. 1H NMR (300 MHz, CDCl3)
ꢂ 8.01–7.19 (m, 25H), 5.90 (t, 1H, J ¼ 9:5 Hz), 5.77 (d, 1H, J ¼
3:0 Hz), 5.64 (dd, 1H, J1 ¼ 10:0 Hz, J2 ¼ 3:9 Hz), 5.01 (t, 1H, J ¼
3:5 Hz), 4.53 (dd, 1H, J1 ¼ 15:4 Hz, J2 ¼ 3:4 Hz), 4.43 (d, 2H,
J ¼ 3:3 Hz), 4.35 (dd, 1H, J1 ¼ 12:1 Hz, J2 ¼ 4:8 Hz), 4.14–
4.07 (m, 1H). 13C NMR (75 MHz, CDCl3) ꢂ 166.0, 165.8, 165.1,
137.3, 136.3, 133.4, 133.3, 132.9, 130.0, 129.73, 129.7, 129.6,
129.4, 128.94, 128.9, 128.4, 128.3, 127.64, 127.6, 126.6, 122.9,
98.0, 76.1, 72.2, 70.9, 66.5, 63.1. LR-FAB-MS: Calcd for
Data for 3,4,6-Tri-O-benzoylmannose NPOE (6a): Rf : 0.38
(25% EtOAc–Hexane). IR (Neat) ꢃmax 2935, 2357, 1721, 1447,
1
1263, 1092, 702 cmꢂ1. H NMR (300 MHz, CDCl3) ꢂ 8.01–7.27

558 Bull. Chem. Soc. Jpn. Vol. 80, No. 3 (2007)
Ionic Liquid-Mediated Synthesis
C41H34O10: 686.22; Found: 709.52 ðM þ NaÞþ.
129.8, 129.7, 129.6, 129.58, 129.52, 129.5, 129.4, 129.2, 128.8,
128.6, 128.4, 128.3, 128.2, 128.0, 126.8, 126.6, 121.3, 116.1,
102.9, 97.5, 76.5, 71.7, 71.6, 69.6, 68.2, 67.5, 61.9, 39.5, 30.2,
28.9, 28.8, 23.6, 22.9, 14.0, 10.9. LR-FAB-MS: Calcd for
C69H66O118: 1182.42; Found: 1205.38 ðM þ NaÞþ.
Data for 3,6,20,30,40,60-Hexa-O-benzoyllactose 4-Pentenyl
Orthoester (8a):
Rf : 0.37 (30% EtOAc–Hexane) IR (Neat)
ꢃmax 3070, 2944, 2666, 2545, 2097, 1971, 1918, 1737, 1713,
1698, 1649, 1542, 1494, 1455, 1314, 1265, 1173, 1100, 1027,
969, 910, 847, 774, 706 cmꢂ1
.
1H NMR (300 MHz, CDCl3) ꢂ
Typical Procedure for the Glycosidation of NPOE of Glu-
8.13–7.09 (m, 35H), 6.10 (d, 1H, J ¼ 2:6 Hz), 6.00 (d, 1H, J ¼
3:0 Hz), 5.95–5.87 (m, 2H), 5.75–5.69 (m, 1H), 5.60 (dd, 1H,
J1 ¼ 10:5 Hz, J2 ¼ 3:6 Hz), 5.12 (d, 1H, J ¼ 8:1 Hz), 5.00–4.90
(m, 2H), 4.67–4.62 (m, 2H), 4.47–4.37 (m, 2H), 4.14–4.10 (m,
3H), 3.80 (d, 1H, J ¼ 9:0 Hz), 3.43–3.40 (m, 1H), 3.26–3.23 (m,
1H), 2.10–2.05 (m, 2H), 1.66–1.61 (m, 2H). 13C NMR (75 MHz,
CDCl3) ꢂ 165.9, 165.7, 165.6, 165.5, 165.1, 164.7, 137.9, 133.6,
133.5, 130.1, 130.0, 129.86, 129.8, 129.6, 129.5, 129.4, 128.8,
128.7, 128.6, 128.5, 128.4, 128.3, 128.1, 121.3, 114.9, 103.0,
97.6, 72.1, 71.8, 71.6, 69.9, 69.7, 68.2, 67.6, 63.6, 62.1, 30.2,
30.0, 28.7, 20.1. LR-FAB-MS: Calcd for C66H58O18: 1138.36;
Found: 1161.70 ðM þ NaÞþ.
cose with Isooctyl Alcohol.
Isooctyl alcohol (0.020 g, 0.16
mmol) and the NPOE 9 (0.20 g, 0.32 mmol) in [bmim]PF6 (2 mL)
were combined, rotoevaporated twice with dry toluene and then
vacuum dried for 3 h. This mixture, cooled with ice, was treated
under argon with NIS (0.72 g, 0.32 mmol) followed by catalytic
addition of Yb(OTf)3 (2 mg, 2 mol %). After 10 min, TLC showed
the reaction to be complete; the mixture was extracted with Et2O
and washed successively with sodium thiosulphate solution and
sodium hydrogen carbonate solution. The organic layer was dried
over anhydrous Na2SO4, and the solvent was removed completely.
The crude sample on purification by column chromatography
afforded pure 10a as a viscous liquid (0.084 g, 79%). The 4-pen-
tenyl glycoside (NPG) formed from excess NPOE was also isolat-
ed as a viscous liquid (0.063 g, 0.10 mmol).
Data for 3,6,20,30,40,60-Hexa-O-benzoyllactose Allyl Ortho-
ester (8b):
3070, 2934, 1727, 1649, 1542, 1455, 1265, 1173, 1095, 1022,
968, 769, 706 cmꢂ1 1H NMR (300 MHz, CDCl3) ꢂ 8.11–7.09
Rf : 0.34 (30% EtOAc–Hexane). IR (Neat) ꢃmax
Data for 2-O-Benzoyl-1-O-isooctyl-3,4,6-tri-O-benzyl-ꢀ-D-
.
glucopyranoside (10a):
Rf : 0.49 (25% EtOAc–Hexane). IR
(m, 35H), 6.10 (d, 1H, J ¼ 2:5 Hz), 5.99 (d, 1H, J ¼ 3:1 Hz),
5.95–5.94 (m, 1H), 5.90–5.87 (m, 1H), 5.85–5.80 (m, 1H), 5.60
(dd, 1H, J1 ¼ 10:4 Hz, J2 ¼ 3:3 Hz), 5.25 (dd, 1H, J1 ¼ 17:2 Hz,
J2 ¼ 1:5 Hz), 5.15–5.10 (m, 2H), 4.69–4.63 (m, 2H), 4.48–4.39
(m, 2H), 4.14–4.08 (m, 3H), 3.93–3.91 (m, 1H), 3.83–3.79 (m,
2H). 13C NMR (75 MHz, CDCl3) ꢂ 165.9, 165.7, 165.6, 164.9,
157.8, 136.8, 135.1, 134.1, 133.7, 133.5, 133.4, 133.1, 132.9,
130.3, 130.1, 130.0, 129.9, 129.8, 129.7, 129.56, 129.5, 129.1,
128.9, 128.7, 128.6, 128.5, 128.3, 127.8, 127.2, 127.1, 127.0,
126.4, 121.6, 120.5, 116.9, 103.3, 98.0, 77.7, 72.2, 72.0, 70.1,
69.9, 68.5, 67.8, 65.6, 63.5, 62.4, 29.9. LR-FAB-MS: Calcd for
C64H54O18: 1110.33; Found: 1133.69 ðM þ NaÞþ.
(Neat) ꢃmax 2928, 1729, 1640, 1449, 1265, 1088, 732, 691 cmꢂ1
.
1H NMR (300 MHz, CDCl3) ꢂ 8.00 (d, 2H, J ¼ 7:55 Hz), 7.54 (t,
1H, J ¼ 7:1 Hz), 7.44–7.11 (m, 17H), 5.26 (t, 1H; C2, J ¼ 8:5
Hz), 4.82 (d, 1H; C1, J ¼ 10:2 Hz), 4.74–4.56 (m, 6H), 4.45
(dd, 1H, J1 ¼ 1:5 Hz, J2 ¼ 7:9 Hz), 3.84–3.68 (m, 4H), 3.53–
3.51 (m, 1H), 3.25 (dd, 1H, J1 ¼ 6:4 Hz, J2 ¼ 9:3 Hz), 1.40–
1.09 (m, 9H), 0.75–0.67 (m, 6H). 13C NMR (75 MHz, CDCl3) ꢂ
165.2, 138.5, 138.3, 138.2, 133.1, 130.5, 130.0, 128.65, 128.6,
128.57, 128.5, 128.2, 128.0, 127.8, 101.8, 83.0, 78.4, 75.6, 75.1,
74.1, 73.8, 72.5, 69.1, 39.7, 30.7, 29.4, 29.0, 23.8, 23.1, 14.3,
11.0. LR-FAB-MS: Calcd for C42H50O7: 666.36; Found: 689.88
ðM þ NaÞþ.
Data for 3,6,20,30,40,60-Hexa-O-benzoyllactose Isopropyl
Orthoester (8c): Rf : 0.29 (30% EtOAc–Hexane). IR (Neat)
Data for 2-O-Benzoyl-1-O-adamantyl-3,4,6-tri-O-benzyl-ꢀ-
D-glucopyranoside (10b): Rf : 0.47 (25% EtOAc–Hexane). IR
(Neat) ꢃmax 2903, 2361, 1721, 1456, 1268, 1099, 1068, 726, 692
ꢃ
max 3066, 2973, 2929, 2861, 1971, 1913, 1728, 1621, 1601, 1577,
1489, 1450, 1348, 1265, 1173, 1100, 1066, 1022, 968, 847, 789,
764, 706 cmꢂ1 1H NMR (300 MHz, CDCl3) ꢂ 8.11–7.12 (m,
cmꢂ1
.
1H NMR (300 MHz, CDCl3): ꢂ 8.03 (d, 2H, J ¼ 7:6 Hz),
.
7.53 (t, 1H, J ¼ 7:2 Hz), 7.43–7.12 (m, 17H), 5.31–5.27 (m, 1H),
5.10 (s, 1H; C2), 4.84–4.80 (m, 2H), 4.70–4.50 (m, 6H), 4.26–4.21
(m, 1H), 4.04–3.93 (m, 2H), 3.85–3.66 (m, 1H), 2.00–1.30 (m,
14H). 13C NMR (75 MHz, CDCl3) ꢂ 167.4, 138.1, 133.7, 132.7,
130.7, 129.7, 128.7, 128.5, 128.4, 127.8, 127.7, 127.65, 127.6,
127.5, 125.9, 99.1 (C1), 94.3, 79.8, 75.1, 74.7, 73.9, 73.3, 68.9,
38.7, 37.3, 36.4, 36.0, 33.3, 31.4, 30.3, 27.2, 23.7. LR-FAB-MS:
Calcd for C44H48O7 688.34; Found: 711.84 ðM þ NaÞþ.
35H), 6.07 (d, 1H, J ¼ 2:5 Hz), 5.98 (d, 1H, J ¼ 3:0 Hz), 5.88 (d,
1H, J ¼ 2:1 Hz), 5.57 (dd, 1H, J1 ¼ 10:4 Hz, J2 ¼ 3:4 Hz), 5.12
(d, 1H, J ¼ 8:1 Hz), 4.68–4.58 (m, 2H), 4.47–4.41 (m, 1H),
4.34–4.30 (m, 1H), 4.13–4.03 (m, 3H), 3.78–3.65 (m, 3H), 1.13
(d, 3H, J ¼ 6:1 Hz), 1.04 (d, 3H, J ¼ 6:2 Hz). 13C NMR (75 MHz,
CDCl3) ꢂ 165.5, 165.4, 165.1, 164.9, 164.5, 133.4, 133.2, 132.9,
132.7, 130.1, 129.9, 129.8, 129.7, 129.6, 129.5, 129.3, 128.9,
128.7, 128.5, 128.4, 128.3, 128.1, 126.9, 126.8, 102.8, 97.6,
71.8, 71.6, 70.0, 69.7, 68.3, 67.3, 63.2, 62.1, 24.7, 23.6, 23.2.
LR-FAB-MS: Calcd for C64H56O18: 1112.35; Found: 1135.53
ðM þ NaÞþ.
Data for 2,3,4-Tri-O-benzyl-1-O-methyl-6-O-(2-benzoyl-
3,4,6-tri-O-benzyl-ꢀ-D-glucopyranosyl)-ꢁ-D-glucopyranoside
(10c): Rf : 0.23 (25% EtOAc–Hexane). IR (Neat) ꢃmax 2926,
1724, 1493, 1451, 1360, 1262, 1099, 1024, 735, 697 cmꢂ1
.
Data for 3,6,20,30,40,60-Hexa-O-benzoyllactose Isooctyl
Orthoester (8d): Rf : 0.38 (30% EtOAc–Hexane). IR (Neat)
ꢃmax 3070, 2959, 2929, 2871, 1971, 1917, 1732, 1601, 1514,
1494, 1450, 1270, 1178, 1100, 1071, 1027, 973, 857, 793, 769,
1H NMR (300 MHz, CDCl3) ꢂ 8.03 (d, 2H, J ¼ 7:2 Hz), 7.55–
7.14 (m, 33H), 5.53 (t, 1H, J ¼ 8:1 Hz), 5.10 (dd, 1H, J1 ¼ 3:5
Hz, J2 ¼ 10:1 Hz), 4.96 (d, 1H, J ¼ 10:9 Hz), 4.88–4.72 (m,
7H), 4.66–4.50 (m, 6H), 4.20 (t, 1H, J ¼ 9:3 Hz), 4.16–4.08 (m,
1H), 3.98 (t, 1H, J ¼ 9:3 Hz), 3.79–3.59 (m, 6H), 3.53–3.45 (m,
2H), 3.36 (s, 3H). 13C NMR (75 MHz, CDCl3) ꢂ 164.5, 138.8,
138.3, 137.6, 137.4, 133.0, 129.6, 129.4, 128.9, 128.2, 106.1,
98.3, 90.7, 81.9, 80.0, 79.2, 78.1, 78.0, 77.3, 77.0, 76.5, 75.0,
74.2, 73.4, 70.7, 70.5, 61.8, 55.2, 52.8. LR-FAB-MS: Calcd for
C44H48O7: 1000.44; Found: 1023.76 ðM þ NaÞþ.
710 cmꢂ1 1H NMR (300 MHz, CDCl3) ꢂ 8.12–7.12 (m, 35H),
.
6.07 (d, 1H, J ¼ 2:6 Hz), 5.99 (d, 1H, J ¼ 3:0 Hz), 5.94–5.86
(m, 2H), 5.58 (dd, 1H, J1 ¼ 10:4 Hz, J2 ¼ 3:3 Hz), 5.10 (d, 1H,
J ¼ 8:0 Hz), 4.68–4.59 (m, 2H), 4.46–4.41 (m, 1H), 4.34–4.32
(m, 1H), 4.14–4.10 (m, 3H), 3.82 (d, 1H, J ¼ 8:9 Hz), 3.32–3.25
(m, 1H), 3.17–3.10 (m, 1H), 1.43–1.21 (m, 8H), 0.87–0.78 (m,
6H). 13C NMR (75 MHz, CDCl3) ꢂ 165.6, 165.5, 165.4, 165.3,
164.9, 164.5, 135.3, 133.4, 133.2, 133.1, 132.8, 132.7, 130.0,
Data for 2,3,4,6-Tetra-O-benzoyl-1-O-isooctyl-ꢀ-D-gluco-
pyranoside (12a): Rf : 0.18 (25% EtOAc–Hexane). IR (Neat)

S. Anas et al.
Bull. Chem. Soc. Jpn. Vol. 80, No. 3 (2007)
559
ꢃmax 2903, 1723, 1452, 1265, 1097, 1071, 729, 693 cmꢂ1
.
128.0, 127.9, 127.8, 127.7, 127.6, 99.5 (C1), 80.8, 74.5, 73.6,
72.4, 71.7, 68.8, 37.7, 37.5, 36.7, 36.3, 34.6, 33.3, 31.1, 31.0,
27.2. LR-FAB-MS: Calcd for C44H48O7: 688.34; Found: 711.79
ðM þ NaÞþ.
1H NMR (300 MHz, CDCl3) ꢂ 8.15 (d, 2H, J ¼ 7:8 Hz), 8.0 (d,
2H, J ¼ 7:7 Hz), 7.97 (d, 2H, J ¼ 7:7 Hz), 7.81 (d, 2H, J ¼ 7:8
Hz), 7.59–7.18 (m, 12H), 5.98 (d, 1H, J ¼ 3:0 Hz), 5.76 (dd,
1H, J1 ¼ 10:5 Hz, J2 ¼ 7:5 Hz), 5.59 (dd, 1H, J1 ¼ 3:3 Hz, J2 ¼
7:2 Hz), 4.77–4.67 (m, 2H), 4.43–4.36 (m, 1H), 4.32–4.25 (m,
1H), 3.90 (dd, 1H, J1 ¼ 4:8 Hz, J2 ¼ 9:6 Hz), 3.39–3.34 (m,
1H), 1.27–1.19 (m, 9H), 0.75–0.64 (m, 6H). 13C NMR (75 MHz,
CDCl3) ꢂ 167.1, 166.9, 165.7, 164.7, 133.7, 133.4, 133.3, 130.3,
130.1, 129.9, 129.8, 129.7, 129.6, 129.5, 129.0, 128.6, 128.5,
128.4, 128.35, 128.3, 128.0, 101.3 (C1), 90.4, 77.7, 71.4, 70.1,
62.1, 30.3, 30.0, 29.3, 28.9, 23.1, 14.3, 11.3. LR-FAB-MS: Calcd
for C42H44O10: 708.29; Found: 731.68 ðM þ NaÞþ.
Data for 2,3,4-Tri-O-benzyl-1-O-methyl-6-O-(2-benzoyl-
3,4,6-tri-O-benzyl-ꢀ-D-galactopyranosyl)-ꢁ-D-glucopyranoside
(14d): Rf : 0.25 (25% EtOAc–Hexane). IR (Neat) ꢃmax 2926,
1724, 1493, 1451, 1262, 1099, 735, 697 cmꢂ1 1H NMR (300
.
MHz, CDCl3) ꢂ 7.92 (d, 2H, J ¼ 7:3 Hz), 7.46 (t, 1H, J ¼ 7:4 Hz),
7.43–7.20 (m, 32H), 5.65 (dd, 1H; C02, J1 ¼ 9:9 Hz, J2 ¼ 7:9 Hz),
4.94 (d, 1H; C01, J ¼ 11:5 Hz), 4.84 (d, 1H, J ¼ 10:9 Hz), 4.70–
4.55 (m, 6H), 4.48–4.40 (m, 6H), 4.30 (d, 1H, J ¼ 11:3 Hz),
4.05 (d, 1H, J ¼ 9:3 Hz), 3.82 (t, 1H, J ¼ 9:2 Hz), 3.64–3.56
(m, 6H), 3.39–3.28 (m, 2H), 3.15 (s, 3H). 13C NMR (75 MHz,
CDCl3) ꢂ 165.1, 133.5, 133.4, 133.2, 130.9, 129.7, 128.5, 128.3,
128.2, 128.0, 127.9, 127.8, 127.7, 127.6, 101.9 (C1), 98.0, 82.3,
80.1, 79.4, 78.3, 77.3, 76.4, 75.3, 74.9, 74.5, 74.8, 73.8, 71.9,
62.3, 56.3, 52.2. LR-FAB-MS: Calcd for C62H64O12: 1000.44;
Found: 1023.26 ðM þ NaÞþ.
Data for 2,3,4,6-Tetra-O-benzoyl-1-O-cyclohexyl-ꢀ-D-gluco-
pyranoside (12b): Rf : 0.20 (25% EtOAc–Hexane). IR (Neat)
ꢃmax 3067, 2961, 1729, 1600, 1449, 1264, 1108, 708 cmꢂ1
.
1H NMR (300 MHz, CDCl3) ꢂ 8.10–7.75 (m, 8H), 7.61–7.26 (m,
12H), 6.24 (t, 1H; C2, J ¼ 9:9 Hz), 5.75–5.70 (m, 2H), 5.29 (dd,
1H, J1 ¼ 3:5 Hz, J2 ¼ 10:2 Hz), 4.67–4.55 (m, 2H), 4.49–4.38
(m, 1H), 3.89 (s, 1H), 2.03–1.23 (m, 10H). 13C NMR (75 MHz,
CDCl3) ꢂ 166.3, 165.8, 165.7, 165.2, 133.8, 133.5, 133.3, 133.1,
130.1, 129.9, 129.82, 129.8, 129.7, 129.6, 129.5, 129.4, 129.1,
129.0, 128.9, 128.7, 128.4, 128.3, 128.2, 98.4 (C1), 90.4, 74.0,
70.2, 67.5, 62.8, 36.5, 33.4, 32.3, 32.1, 31.0, 29.8. LR-FAB-MS:
Calcd for C40H38O10: 678.25; Found: 701.36 ðM þ NaÞþ.
Data for 2-O-Benzoyl-3,4,6-tri-O-benzyl-1-O-isooctyl-ꢁ-D-
mannopyranoside (16a): Rf : 0.49 (25% EtOAc–Hexane). IR
(Neat) ꢃmax 2931, 1728, 1643, 1494, 1263, 1096, 1087, 732,
698, 459 cmꢂ1
.
1H NMR (300 MHz, CDCl3) ꢂ 8.04 (d, 2H, J ¼
7:6 Hz), 7.51 (t, 1H, J ¼ 7:3 Hz), 7.49–7.16 (m, 17H), 5.54 (s,
1H), 4.84 (s, 1H; C1), 4.83–4.70 (m, 3H), 4.56–4.50 (m, 3H),
4.03 (d, 2H, J ¼ 5:5 Hz), 3.90–3.66 (m, 4H), 3.34–3.29 (m, 1H),
1.47–1.13 (m, 9H), 0.76–0.65 (m, 6H). 13C NMR (75 MHz,
CDCl3) ꢂ 165.7, 137.6, 133.1, 129.9, 129.8, 128.5, 128.4, 128.3,
128.2, 127.9, 127.5, 127.4, 98.2 (C1), 77.7, 73.6, 71.6, 71.4,
70.7, 69.9, 68.5, 67.2, 39.6, 32.0, 30.6, 29.2, 23.9, 23.1, 14.2,
11.3. LR-FAB-MS: Calcd for C42H50O7: 666.36; Found: 689.46
ðM þ NaÞþ.
Data for 2-O-Benzoyl-3,4,6-Tri-O-benzyl-1-O-isooctyl-ꢀ-D-
galactopyranoside (14a): Rf : 0.48 (25% EtOAc–Hexane). IR
(Neat) ꢃmax 2923, 2368, 1726, 1449, 1265, 1092, 732, 691 cmꢂ1
.
1H NMR (300 MHz, CDCl3) ꢂ 8.01 (d, 2H, J ¼ 7:2 Hz), 7.60 (t,
1H, J ¼ 7:2 Hz), 7.48–7.11 (m, 17H), 5.60 (dd, 1H; C2, J1 ¼
8:1 Hz, J2 ¼ 10:2 Hz), 4.97 (d, 1H; C1, J ¼ 11:7 Hz), 4.70–4.54
(m, 3H), 4.50–4.37 (m, 3H), 3.99 (d, 1H, J ¼ 2:4 Hz), 3.83–3.75
(m, 2H), 3.72–3.56 (m, 3H), 3.24–3.21 (m, 1H), 1.41–1.10 (m,
9H), 0.76–0.67 (m, 6H). 13C NMR (75 MHz, CDCl3) ꢂ 165.1,
138.3, 138.1, 137.8, 132.8, 130.4, 129.7, 128.4, 128.3, 128.0,
127.9, 127.6, 127.5, 99.3 (C1), 81.5, 77.7, 75.3, 74.8, 73.8,
72.2, 72.0, 69.2, 39.2, 30.5, 29.1, 28.6, 23.4, 22.6, 14.2,
11.1. LR-FAB-MS: Calcd for C42H50O7: 666.36; Found: 689.66
ðM þ NaÞþ.
Data for 2-O-Benzoyl-3,4,6-tri-O-benzyl-1-O-cyclohexyl-ꢁ-
D-mannopyranoside (16b):
Rf : 0.52 (25% EtOAc–Hexane).
IR (Neat) ꢃmax 3030, 2925, 1720, 1605, 1497, 1452, 1358, 1261,
1104, 974, 907, 732 cmꢂ1. 1H NMR (300 MHz, CDCl3) ꢂ 7.98 (d,
2H, J ¼ 7:5 Hz), 7.47 (t, 1H, J ¼ 7:2 Hz), 7.47–7.11 (m, 18H),
5.56 (s, 1H), 4.96 (s, 1H; C1), 4.80–4.64 (m, 4H), 4.49–4.44 (m,
3H), 4.08–3.96 (m, 2H), 3.82–3.79 (d, 2H, J ¼ 6:0 Hz), 3.67–
3.64 (m, 1H), 2.01–1.18 (m, 10H). 13C NMR (75 MHz, CDCl3)
ꢂ 165.5, 138.5, 138.4, 138.0, 133.1, 130.0, 129.9, 128.5, 128.4,
128.3, 128.2, 128.1, 128.0, 127.9, 127.8, 127.6, 127.5, 127.4,
97.2 (C1), 78.4, 75.3, 74.3, 73.5, 71.9, 71.6, 69.4, 69.0, 36.6,
33.6, 32.4, 32.2, 31.0, 29.7. LR-FAB-MS: Calcd for C40H44O7:
636.31; Found: 659.68 ðM þ NaÞþ.
Data for 2-O-Benzoyl-1-O-cyclohexyl-3,4,6-tri-O-benzyl-ꢀ-
D-galactopyranoside (14b): Rf : 0.40 (25% EtOAc–Hexane).
IR (Neat) ꢃmax 2934, 2361, 1722, 1527, 1346, 1265, 1065, 803,
694 cmꢂ1
.
1H NMR (300 MHz, CDCl3) ꢂ 8.01 (d, 2H, J ¼ 7:5
Hz), 7.56 (t, 1H, J ¼ 7:5 Hz), 7.46–7.10 (m, 17H), 5.57 (dd, 1H;
C2, J1 ¼ 8:1 Hz, J2 ¼ 9:9 Hz), 4.97 (d, 1H; C1, J ¼ 11:7 Hz),
4.68–4.60 (m, 2H), 4.53 (d, 1H, J ¼ 8:1 Hz), 4.48–4.41 (m, 3H),
3.98 (d, 1H, J ¼ 2:1 Hz), 3.68–3.53 (m, 5H), 1.92–1.10 (m,
10H). 13C NMR (75 MHz, CDCl3) ꢂ 165.7, 133.5, 133.4, 133.1,
130.8, 129.7, 128.6, 128.4, 128.2, 128.0, 127.9, 127.7, 127.64,
127.6, 99.1 (C1), 81.3, 75.0, 74.4, 73.6, 72.5, 71.6, 68.9, 36.6,
33.6, 32.4, 32.2, 30.9, 28.5. LR-FAB-MS: Calcd for C40H44O7:
636.31; Found: 659.77 ðM þ NaÞþ.
Data for 2,3,4-Tri-O-benzyl-1-O-methyl-6-O-(2-benzoyl-
3,4,6-tri-O-benzyl-ꢁ-D-mannopyranosyl)-ꢁ-D-glucopyranoside
(16c): Rf : 0.40 (25% EtOAc–Hexane). IR (Neat) ꢃmax 3037,
2927, 1724, 1456, 1356, 1277, 1024, 738, 694 cmꢂ1 1H NMR
.
(300 MHz, CDCl3) ꢂ 8.05 (d, 2H, J ¼ 8:1 Hz), 7.48 (t, 1H, J ¼
7:3 Hz), 7.36–7.16 (m, 32H), 5.61 (s, 1H), 4.98 (d, 2H, J ¼ 9:6
Hz), 4.86 (d, 2H, J ¼ 11:1 Hz), 4.80–4.73 (m, 3H), 4.70–4.64
(m, 2H), 4.59–4.56 (m, 2H), 4.52–4.42 (m, 3H), 4.04–3.94 (m,
3H), 3.83 (dd, 1H, J1 ¼ 3:6 Hz, J2 ¼ 10:9 Hz), 3.75–3.72 (m, 3H),
3.64 (d, 1H, J ¼ 11:4 Hz), 3.54 (dd, 2H, J1 ¼ 3:3 Hz, J2 ¼ 9:7
Hz), 3.43 (t, 1H, J ¼ 9:5 Hz), 3.32 (s, 3H). 13C NMR (75 MHz,
CDCl3) ꢂ 165.5, 138.8, 138.6, 138.5, 138.3, 138.2, 137.8, 133.0,
130.1, 128.5, 128.4, 128.3, 128.2, 128.1, 128.0, 127.9, 127.8,
127.7, 127.5, 127.4, 98.2 (C01), 97.9 (C001), 82.1, 80.2, 77.6,
77.5, 77.2, 75.8, 75.2, 74.9, 74.2, 73.4, 71.8, 71.4, 69.8, 68.9,
68.7, 66.2, 55.1. LR-FAB-MS: Calcd for C62H64O12: 1000.44;
Found: 1023.69 ðM þ NaÞþ.
Data for 2-O-Benzoyl-1-O-adamantyl-3,4,6-tri-O-benzyl-ꢀ-
D-galactopyranoside (14c):
IR (Neat) ꢃmax 2903, 1723, 1452, 1265, 1097, 1071, 728, 693
cmꢂ1
Rf : 0.45 (25% EtOAc–Hexane).
.
1H NMR (300 MHz, CDCl3) ꢂ 8.04 (d, 2H, J ¼ 7:6 Hz),
7.53 (t, 1H, J ¼ 7:3 Hz), 7.50–7.10 (m, 17H), 5.64 (dd, 1H; C2,
J1 ¼ 8:1 Hz, J2 ¼ 9:9 Hz), 4.98 (d, 1H; C1, J ¼ 12 Hz), 4.71–
4.58 (m, 2H), 4.54 (d, 1H, J ¼ 7:8 Hz), 4.49–4.41 (m, 3H), 3.99
(d, 1H, J ¼ 2:4 Hz), 3.75 (s, 1H), 3.66–3.55 (m, 4H), 2.09–1.67
(m, 10H), 1.43–0.69 (m, 4H). 13C NMR (75 MHz, CDCl3) ꢂ
165.7, 133.5, 133.4, 133.2, 130.9, 129.7, 128.5, 128.3, 128.2,

560 Bull. Chem. Soc. Jpn. Vol. 80, No. 3 (2007)
Ionic Liquid-Mediated Synthesis
9 A. Rencurosi, L. Lay, G. Russo, E. Caneva, L. Poletti,
J. Org. Chem. 2005, 70, 7765.
The authors thank Council of Scientific and Industrial Re-
search (CSIR), New Delhi, for financial assistance (Task Force
Project-CMM-005 on Specialty Chemicals). SA and SVS
thank CSIR, New Delhi for Research Fellowship. Financial
assistance from DST, New Delhi (No: SR/S1/OC-38/2003),
is greatly acknowledged. We thank Dr. R. Luxmi Varma,
Ms. Soumini Mathew and Ms. S. Viji for the NMR and mass
spectra reported in this paper.
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