AuIII-halide/phenylacetylene-catalysed glycosylations using 1-o-acetylfuranoses and pyranose 1,2-orthoesters as glycosyl donors

Article abstract of DOI:10.1002/ejoc.201501245

1-O-Acetylfuranoses and pyranose 1,2-orthoesters were activated with an Au^III halide/phenylacetylene relay catalyst system, and they acted as excellent glycosyl donors. Thus, 1-O-acetyl-D-ribofuranose, 1-O-acetyl-D-lyxofuranose, and 1,2-orthoesters selectively gave the corresponding 1,2-trans glycosides, whereas 1-O-acetyl-D-arabinofuranose and 1-O-acetyl-D-xylofuranose both gave mixtures of 1,2-trans and 1,2-cis glycosides, with the 1,2-trans glycosides predominating. A new glycosylation method has been developed for 1-O-acetylfuranoses and pyranose 1,2-orthoesters, using Au^III halides and phenylacetylene as relay catalyst systems. Good anomeric selectivity was observed for 1-O-acetylfuranoses, and excellent selectivity was observed for pyranose 1,2-orthoesters. The corresponding glycosides were formed in moderate to good yields.

Full text of DOI:10.1002/ejoc.201501245

DOI: 10.1002/ejoc.201501245
Full Paper
Glycosylation
AuIII-Halide/Phenylacetylene-Catalysed Glycosylations Using
1-O-Acetylfuranoses and Pyranose 1,2-Orthoesters as Glycosyl
Donors
Asadulla Mallick,[a] Yakkala Mallikharjunarao,[a] Parasuraman Rajasekaran,[a] Rashmi Roy,[a]
and Yashwant D. Vankar*[a]
Abstract: 1-O-Acetylfuranoses and pyranose 1,2-orthoesters orthoesters selectively gave the corresponding 1,2-trans glycos-
were activated with an AuIII halide/phenylacetylene relay cata- ides, whereas 1-O-acetyl-
D
-arabinofuranose and 1-O-acetyl-
D-
lyst system, and they acted as excellent glycosyl donors. Thus, xylofuranose both gave mixtures of 1,2-trans and 1,2-cis glycos-
1-O-acetyl-
D
-ribofuranose, 1-O-acetyl-
D
-lyxofuranose, and 1,2- ides, with the 1,2-trans glycosides predominating.
Introduction
gold(III) salts.[16] These properties have been exploited in the
synthesis of O-linked glycosides, using propargyl pyranosides,
The majority of carbohydrates are not found in their free forms
in nature. Monosaccharides are linked through glycosidic bonds
to other monosaccharides, or to aglycons such as lipids, pept-
ides, or proteins to form oligosaccharides or glycoconjugates.
Depending on the nature of the linkage, they can be classified
as N-, O-, C-, or S-linked glycosides. O-Linked glycosides are
most common and important.[1] For example, O-linked glycos-
ides have been found to behave as antibacterial,[2] antiviral,[3]
antifungal,[4] antitumor[5] and anti-HIV[6] agents. As a conse-
quence, the synthesis of biologically important oligosaccharides
and glycoconjugates has been a prime concern for chemists,
and a large number of glycosylation methods have been devel-
oped for this purpose.[7] Different kinds of glycosyl donors have
been introduced, and many activators have been developed
to effect glycosylation reactions. These glycosyl donors include
thioglycosides,[8] glycosyl sulfoxides,[9] glycosyl sulfones,[10] tri-
chloroacetimidates,[11] n-pentenyl glycosides,[12] 1,2-ortho-
esters,[13] and many more.[7c] However, reports of the use of
1-O-acetyl sugars as glycosyl donors are few.[14] Glycosylation
propargyl furanosides, and propargyl 1,2-orthoesters as glycosyl
donors.[17] These methods, although efficient, require the do-
nors to have an inbuilt acetylenic moiety for activation with
gold salts. In contrast, our method[15] to activate OAc as an
anomeric leaving group needs only catalytic amounts of both
AuCl3 and phenylacetylene. As an extension of our work, we
report in this paper O-glycosylation using 1-O-acetylfuranoses
and 1,2-orthoesters using AuIII halide catalysts with or without
a phenylacetylene cocatalyst. The glycosylation of furanoses is
important as several glycoconjugates contain oligofuranoside
units.[17,18] Glycosyl 1,2-orthoesters are also excellent glycosyl
donors in carbohydrate chemistry.[13] As expected, we found
that AuIII halide/phenylacetylene relay catalyst systems are bet-
ter than only gold-catalysed reactions in terms of time and
yield.
Results and Discussion
reactions of 1-O-acetyl sugars suffer from drawbacks such as We used four different benzyl-ether-protected furanose sugars
requiring excess of the promoter,[14a–14c] long reaction 1a,[18] 1b, 1c,[19] and 1d (Figure 1) as glycosyl donors, and 2a–
times,[14d,14e] and harsh reaction conditions.[14a] In this context, 2h (Figure 2) were used as glycosyl acceptors. We began our
we recently reported[15] a new relay catalyst system comprising investigation with acetate-protected
D
-arabinofuranose-derived
AuIII chloride and phenylacetylene, which was able to activate glycosyl donor
D
-Araf 3[20] (Table 1) and acceptor 2a, which
1-O-acetyl pyranoses as glycosyl donors and overcome these were treated with gold(III) chloride (5 mol-%) and phenyl-
drawbacks. In this approach, AuCl3 and phenylacetylene were acetylene (5 mol-%) in CH2Cl2. This reaction did not lead to the
both used in only catalytic amounts. In recent years, gold-cata- desired compound (i.e., 4; Table 1, entry 1). We then carried out
lysed reactions have gained significant attention due to the the same reaction using benzylated acetyl furanoside 1a with
high alkynophilicity and Lewis acidity of both gold(I) and acceptor 2a (Table 1, entry 2), and to our delight we obtained
the desired glycosylated product (i.e., 4a)[17a] within 2 h in mod-
[a] Department of Chemistry, Indian Institute of Technology,
erate yield. We optimized the reaction conditions by varying
the catalyst loading and changing the solvent of the reaction
medium (Table 1). We found that a catalyst loading of 10 mol-
% [gold(III) chloride/phenylacetylene (1:1)] and CH2Cl2 as sol-
vent gave the best results (Table 1, entry 4). So we took these
Kanpur 208016, India
E-mail: vankar@iitk.ac.in
http://home.iitk.ac.in/~vankar/
Supporting information for this article is available on the WWW under
http://dx.doi.org/10.1002/ejoc.201501245.
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as the optimized conditions. We repeated the reaction without
adding phenylacetylene to see its effect (Table 1, entry 6). The
reaction with phenylaceylene was clearly better in terms both
of yield and of time taken. Having optimized the reaction condi-
Table 2. AuCl3/phenylacetylene-mediated glycosylations of
1b, -Ribf 1c, and -Xylf 1d.
D-Araf 1a, D-Lyxf
D
D
tions, we allowed -Araf 1a to react with other acceptors, and
D
the details are given in Table 2, entries 1–5. In most cases, we
obtained a mixture of 1,2-trans and 1,2-cis glycosides, but com-
pound 4c was obtained as a single α isomer (Table 2, entry 2).
We found also here that when phenylacetylene was not added,
the reactions were rather slow and lower yielding.
Figure 1. 1-O-Acetylfuranoses as glycosyl donors.
[a] The reactions were carried out using AuCl3 (10 mol-%) and phenylacety-
lene (10 mol-%). [b] The reactions were carried out using AuCl3 (10 mol-%).
[c] The α/β ratio was determined from 1H NMR spectroscopic analysis. [d] The
anomers were separated by column chromatography. [e] The reactions were
carried out using AuCl3 (10 mol-%), AgOTf (10 mol-%), and phenylacetylene
(10 mol-%). [f] N.r.: no reaction.
2f (Table 2, entries 6–11). The corresponding glycosides were
formed as α isomers, except for compounds 5b and 5d, which
were formed as mixtures of anomers (Table 2, entries 7 and 9)
Figure 2. Glycosyl acceptors.
with the α isomers predominating. Similarly,
D-ribofuranose do-
nor -Ribf 1c was subjected to gold(III)-chloride/phenylacetyl-
D
Table 1. Optimization of reaction conditions for gold-catalysed glycosylation.
ene-catalysed glycosylation. In most cases, complete β-selectiv-
ity was observed, except for product 6b (Table 2, entry 13)
which was formed with a small amount of the α isomer also.
Finally, D-xylofuranose donor D-Xylf 1d was coupled with 2a–
2f. Mixtures of 1,2-trans and 1,2-cis glycosides were obtained
with all the acceptors (Table 2, entries 18–23), with the β isomer
predominating slightly. We also ran all of the the glycosylation
reactions with AuCl3 alone, but the reactions were not as effect-
ive as when the AuCl3/phenylacetylene reagent system was
used (Table 2). D-Xylofuranose donor D-Xylf 1d did not react
with sugar-derived acceptors 2g and 2h under these condi-
tions, with or without phenylacetylene. On the other hand, pro-
longing the reaction led to hydrolysis of 1d. However, 1d re-
acted with 2g as well as 2h in the presence of silver triflate to
form the corresponding disaccharides (i.e., 7g and 7h, respec-
tively), albeit in rather low yields (Table 2, entries 24 and 25).
With the hindered glycosyl acceptors 2c and 2d, we obtained
Then, we took D-lyxofuranose derivative D-Lyxf 1b as a glyc-
osyl donor, and ran glycosylation reactions with acceptors 2a– maximum yields of 55 % of 7c, and 74 % of 7d, respectively
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(Table 2, entries 20 and 21) using the AuCl3/phenylacetylene acetylene are regenerated from complex B, and acetic acid is
reagent system. The structures of glycosides 4–7 are shown in formed.[21]
Figure 3.
Having demonstrated the use of 1-O-acetylfuranoses as glyc-
-glucose-
A possible catalytic cycle for the AuCl3/phenylacetylene rea- osyl donors, we turned our attention to the use of
D
gent system is given in Figure 4. First, the AuCl3/phenyl- derived 1,2-orthoester 8[22] as a glycosyl donor. A 1,2-orthoester
acetylene complex activates the anomeric acetate group to can be considered to be a masked acetate group (Figure 5).
form a donor–AuCl3–phenylacetylene complex A, which can Initially, we tried to couple 1,2-orthoester 8 with glycosyl ac-
give an oxocarbenium ion C through expulsion of intermediate ceptor 2a using the AuCl3/phenylacetylene catalyst system. But
B. Oxocarbenium ion C is then trapped by a glycosyl acceptor this gave a complex mixture (Table 3, entry 1). We therefore
(ROH) to give glycosylated product D. AuCl3 and phenyl- tested benzyl-protected methyl 1,2-orthoester 9[23] in the
Figure 3. Different glycosides from 1-O-acetylfuranoses.
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Table 4. AuBr3/phenylacetylene-mediated glycosylation of 1,2-orthoesters.
Figure 4. Possible catalytic cycle for the AuCl3/phenylacetylene-catalysed
glycosylation.
AuCl3/phenylacetylene-catalysed glycosylation, and this gave
the desired glycoside (i.e., 12a) in 61 % yield (Table 3, entry 2)
within 10 min. We then carried out the same reaction using
AuBr3, which appeared to be a better catalyst than AuCl3 as we
obtained a higher yield (76 %) of 12a. Changing the solvent
from CH2Cl2 to CH3CN led to a drop in the yield (49 %, Table 3,
entry 4).
[a] The reactions were carried out using AuBr3 (10 mol-%) and phenylacetyl-
ene (10 mol-%). [b] The reactions were carried out using AuBr3 (10 mol-%).
Benzyl-protected
D
-galactose 1,2-orthoester 10[23] and
D-
mannose 1,2-orthoester 11[23] were also tested for glycosyla-
tions using the AuBr3/phenylacetylene reagent system (Table 4).
All the reactions of benzyl-protected pyranose 1,2-orthoesters
were found to be 1,2-trans selective.[13] Attempts to react 1,2-
orthoesters with glycosyl acceptors 2g and 2h led only to
methyl glycosides, which indicates that intramolecular OMe
transfer is faster than the reactions to form disaccharides with
sugar-derived secondary alcohols.
Figure 5. Pyranose 1,2-orthoesters as glycosyl donors.
Table 3. Optimization of reaction conditions for pyranose 1,2-orthoesters as
glycosyl donors.
A possible catalytic cycle for the glycosylation of orthoesters
using the AuBr3/phenylacetylene reagent system is shown in
Figure 7. First, the AuBr3–phenylacetylene complex may acti-
vate the orthoester group to form dioxolenium ion E[13a–13d,17b]
and AuBr3–phenylacetylene–OMe complex F. The glycosyl ac-
ceptor (ROH) then attacks the anomeric carbon of intermediate
E to give the desired glycoside product (i.e., G). AuBr3 and phe-
nylacetylene are regenerated from complex F, and methanol is
formed. From the catalytic cycle it is obvious that methanol is
Hence, we took the conditions shown in Table 3, entry 3 as formed during the glycosylation reaction. This methanol could
optimized conditions, and carried out glycosylation reactions then also attack dioxolenium ion E to give methyl glycosides
between donor 9 and acceptors 2b–2f. The results are pre- 15,[24a,24b] 16,[24b] and 17[25] from
D
-glucose,
D-galactose, and
sented in Table 4. The structures of the glycoside products (i.e.,
D-mannose-derived glycosyl donors, respectively. These methyl
12–17) are shown in Figure 6. We then repeated all the reac- glycosides were formed in only 5–10 % yield as side-products.
tions without adding phenylacetylene, and found that the reac- Pyranose 1,2-orthoesters were found to be more reactive than
tions with phenylacetylene were better than those without 1-O-acetylfuranoses in the glycosylation reactions, as in all cases
phenylacetylene in terms of reaction time and yield.
the reactions were complete within 10–15 min. The only excep-
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Figure 6. Different glycosides from 1,2-orthoesters.
tion was 13c (Table 4, entry 9), which required 1 h to reach Conclusions
completion for both reactions (with and without phenylacetyl-
ene).
In conclusion, gold(III) halide/phenylacetylene reagent systems
were found to work effectively with 1-O-acetylfuranoses and
pyranose 1,2-orthoesters to give the corresponding glycosides
in good yield and with good selectivity. This indicates that there
is a special role for phenylacetylene in gold-catalysed glycosyl-
ations of 1-O-acetylfuranoses and pyranose 1,2-orthoesters.
Experimental Section
General Methods: FTIR spectra were recorded as thin films or KBr
pellets, and the data are expressed in cm–1 1H (400 or 500 MHz)
.
and 13C (100 and 125 MHz) NMR spectra were recorded with JEOL
JNM-LA 400 or 500 spectrometers in CDCl3 solutions using tetra-
methylsilane as the internal standard. Mass spectra were recorded
with a Waters HAB 213 Q-Tof Premier Micromass spectrometer. Opti-
cal rotations were recorded with an Autopol IV automatic polarime-
ter at the wavelength of the sodium D-line (589 nm) at 25 °C. Col-
umn chromatography was carried out on silica gel (100–200 mesh),
Figure 7. Possible catalytic cycle for
phenylacetylene as catalyst.
D
-glucose 1,2-orthoesters using AuBr3/
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and thin-layer chromatography (TLC) was carried out on silica gel mers), 4.80–4.67 (m, 12 H, both anomers), 4.11–3.49 (m, 10 H, both
plates made using grade-G silica gel, or on Merck precoated silica
gel plates. Glycosyl donors 2e[26] and 2f[27] were prepared by stand-
ard literature procedures.
anomers), 2.08 (s, 3 H, β anomer), 2.04 (s, 3 H, α anomer) ppm. 13C
NMR (125 MHz, CDCl3): δ = 169.3, 138.4, 138.2, 137.9, 128.5, 128.4,
128.0, 127.9, 127.8, 127.7, 127.5, 92.1, 77.8, 74.5, 74.3, 73.2, 73.0,
72.9, 64.1, 63.5, 21.1 ppm. HRMS: calcd. for C28H30NaO6 [M + Na]+
485.1940; found 485.1941.
General Procedure for the Glycosylation of 1-O-Acetylfuranoses
Catalysed by AuCl3/Phenylacetylene: 2,3,5-Tri-O-benzyl-1-O-
acetyl-D-furanose (100 mg, 0.216 mmol) was dissolved in anhydrous
2,3,5-Tri-O-benzyl-1-O-acetyl-
D-xylofuranose (1d): To prepare 1d
from 2,3,5-tri-O-benzyl-
D
-xylofuranose,[28] the same procedure was
CH2Cl2 (5 mL). A glycosyl acceptor (1.2 equiv.) and phenylacetylene
(2.4 μL, 10 mol-%) were added at room temperature, followed by
AuCl3 (6.5 mg, 10 mol-%). The resulting solution was stirred at room
temperature until TLC showed that the starting material had been
completely consumed. The reaction was then quenched by adding
water and the mixture extracted with dichloromethane (2 × 3 mL).
The organic layer was separated, dried with anhydrous sodium
sulfate and concentrated to dryness under reduced pressure. The
residue was purified by silica gel column chromatography (hexane
and ethyl acetate as the eluent) to give the pure glycosides.
followed as for the preparation of 1b. This gave 1d (89 %) as an
inseparable mixture of anomers (α/β = 1:1.1). Rf: 0.5 (hexane/ethyl
acetate, 8:2). IR (neat):
ν = 3031, 2871, 1754, 1365, 1225,
˜
1090 cm–1. H NMR (400 MHz, CDCl3): δ = 7.37–7.27 (m, 30 H, both
anomers), 6.20 (d, J = 3.2 Hz, 1 H, β anomer), 5.55 (d, J = 7.3 Hz, 1
H, α anomer), 4.93–4.62 (m, 12 H, both anomers), 3.96–3.85 (m, 2
H, both anomers), 3.75 (d, J = 5.4 Hz, 1 H, α anomer), 3.66–3.57 (m,
5 H, both anomers), 3.51–3.47 (m, 1 H, α anomer), 3.39–3.33 (m, 1
H, β anomer), 2.15 (s, 3 H, β anomer), 2.03 (s, 3 H, α anomer) ppm.
13C NMR (125 MHz, CDCl3): δ = 169.8, 169.4, 138.7, 138.5, 138.2,
138.1, 138.0, 137.7, 128.6, 128.5, 128.1, 128.0, 127.9, 127.8, 127.7,
94.7, 90.1, 83.7, 81.2, 80.5, 78.6, 77.6, 75.8, 75.7, 75.1, 73.8, 73.5, 73.4,
64.6, 62.2, 21.1, 21.0 ppm. HRMS: calcd. for C28H30NaO6 [M + Na]+
485.1940; found 485.1945.
1
Procedure for the Glycosylation of 1-O-Acetylfuranoses Cata-
lysed by AuCl3: A procedure similar to that described above was
followed, but phenylacetylene was omitted.
Procedure for the Glycosylation of 2,3,5-Tri-O-benzyl-1-O-
acetyl-
D
-xylofuranose (1d): 2,3,5-Tri-O-benzyl-1-O-acetyl-D-xylo-
4-Penten-1-yl 2,3,5-Tri-O-benzyl-D-arabinofuranoside (α-4b and
furanose 1d (100 mg, 0.216 mmol) was dissolved in anhydrous
CH2Cl2 (5 mL). A glycosyl acceptor (7g or 7h; 1.2 equiv.) and phenyl-
acetylene (2.4 μL, 10 mol-%) were added at room temperature, fol-
lowed by AuCl3 (6.5 mg, 10 mol-%) and AgOTf (5.5 mg, 10 mol-%).
The resulting solution was stirred at room temperature until TLC
indicated that the starting material had been completely con-
sumed. The reaction mixture was evaporated to dryness under re-
duced pressure. The residue was purified by silica gel column chro-
matography (hexane and ethyl acetate as eluent) to give the pure
glycosides.
β-4b): IR (neat): ν = 3030, 2923, 2854, 1453, 1364, 1099, 1027 cm–1.
˜
1H NMR (500 MHz, CDCl3): δ = 7.36–7.26 (m, 30 H, both anomers),
5.82–5.74 (m, 2 H, both anomers), 5.04–4.87 (m, 6 H, both anomers),
4.69–4.47 (m, 12 H, both anomers), 4.23–3.91 (m, 6 H, both ano-
mers), 3.76–3.51 (m, 6 H, both anomers), 3.44–3.40 (m, 1 H, α ano-
mer), 3.44–3.40 (m, 1 H, β anomer), 2.14–2.08 (m, 4 H, both ano-
mers), 1.71–1.61 (m, 4 H, both anomers) ppm. 13C NMR (125 MHz,
CDCl3): δ = 138.3, 138.2, 138.1, 138.0, 137.7, 128.5, 128.4, 128.1,
127.9, 127.8, 127.7, 127.6, 114.9, 106.2, 100.7, 88.5, 84.3, 83.6, 83.5,
80.5, 80.2, 73.4, 72.7, 72.5, 72.4, 72.2, 72.0, 69.8, 67.4, 67.0, 30.4, 29.8,
28.8, 28.7 ppm. HRMS: calcd. for C31H36NaO5 [M + Na]+ 511.2460;
found 511.2462.
General Procedure for the Glycosylation of Pyranose 1,2-Or-
thoesters Catalysed by AuBr3/Phenylacetylene: A pyranose 1,2-
orthoester (100 mg, 0.197 mmol) was dissolved in anhydrous CH2Cl2
(10 mL). A glycosyl acceptor (1.5 equiv.) and phenylacetylene
(2.1 μL, 10 mol-%) were added at room temperature, followed by
AuBr3 (8.6 mg, 10 mol-%). The resulting solution was stirred at room
temperature until TLC indicated that the starting material had been
completely consumed. The reaction was then quenched by adding
water and the mixture extracted with dichloromethane (2 × 3 mL).
The organic layer was separated, dried with anhydrous sodium
sulfate and concentrated to dryness under reduced pressure. The
residue was purified by silica gel column chromatography (hexane
and ethyl acetate as eluent) to give the pure glycosides.
Adamantanyl 2,3,5-Tri-O-benzyl-α-
D-arabinofuranoside (4c):
˜
[α]D25 = +27.15 (c = 1.1, CH2Cl2). IR (neat): ν = 3030, 2907, 2851, 1453,
1111, 1090 cm–1 1H NMR (400 MHz, CDCl3): δ = 7.36–7.25 (m, 15
.
H), 5.44 (s, 1 H), 4.61–4.46 (m, 6 H), 4.25–4.22 (m, 1 H), 4.01–4.00
(m, 1 H), 3.92 (m, 1 H), 3.64 (dd, J = 4.4, 10.9 Hz, 1 H), 3.57 (dd, J =
4.4, 10.9 Hz, 1 H), 2.13 (br. s, 3 H), 1.84 (m, 6 H), 1.64–1.59 (m, 6 H)
ppm. 13C NMR (125 MHz, CDCl3): δ = 138.4, 138.2, 137.9, 128.6,
128.4, 128.3, 128.0, 127.9, 127.8, 127.7, 127.6, 127.5, 100.1, 89.6, 83.3,
79.6, 74.4, 73.3, 72.1, 71.8, 69.9, 42.8, 36.4, 30.7 ppm. HRMS: calcd.
for C36H42NaO5 [M + Na]+ 577.2930; found 577.2930.
Cholesteryl
2,3,5-Tri-O-benzyl-α-
D
-arabinofuranoside
˜
(4d):
General Procedure for the Glycosylation of Pyranose 1,2-Or-
thoesters Catalysed by AuBr3: A procedure similar to that de-
scribed above was followed, but phenylacetylene was omitted.
[α]D25 = –48.2 (c = 0.4, CH2Cl2). IR (neat): ν = 3030, 2931, 2866, 1453,
1375, 1114, 1027 cm–1. 1H NMR (400 MHz, CDCl3): δ = 7.36–7.24 (m,
15 H), 5.31 (d, J = 5.0 Hz, 1 H), 5.05 (d, J = 4.1 Hz, 1 H), 4.68–4.52
(m, 6 H), 4.08–4.02 (m, 3 H), 3.59–3.50 (m, 2 H), 3.46–3.42 (m, 1 H),
2.24–2.01 (m, 2 H), 2.04–1.75 (m, 5 H), 1.55–0.96 (m, 24 H), 0.89 (d,
J = 6.4 Hz, 3 H), 0.86–0.84 (m, 6 H), 0.66 (s, 3 H) ppm. 13C NMR
(125 MHz, CDCl3): δ = 140.7, 138.3, 138.1, 137.8, 128.5, 128.4, 128.2,
127.9, 127.7, 127.6, 121.8, 99.1, 84.0, 83.6, 80.0, 77.6, 73.4, 73.0, 72.4,
56.8, 56.2, 50.2, 42.4, 39.8, 39.6, 38.8, 37.4, 36.8 36.2, 35.8, 32.0, 31.9,
29.7, 28.3, 28.1, 24.3, 23.9, 22.9, 22.6, 21.1, 19.4, 18.8, 11.9 ppm.
HRMS: calcd. for C53H72NaO5 [M + Na]+ 811.5277; found 811.5275.
2,3,5-Tri-O-benzyl-1-O-acetyl-
D-lyxofuranose (1b): 2,3,5-Tri-O-
benzyl-
D
-lyxofuranose[28a] (1 g, 2.37 mmol) was dissolved in dry
CH2Cl2 (20 mL). Ac2O (0.31 mL, 2.86 mmol), Et3N (0.50 mL,
3.57 mmol), and a catalytic amount of DMAP (28 mg, 0.23 mmol)
were added. The mixure was stirred for 2 h, then it was quenched
by the addition of water (30 mL). The aqueous layer was extracted
with CH2Cl2 (3 × 10 mL). The combined organic layers were washed
with water, and brine, dried with NaSO4, filtered, and concentrated.
The residue was purified by chromatography on silica gel to give
1b (976 mg, 88 %) as an inseparable mixture of anomers (α/β =
Cholesteryl 2,3,5-Tri-O-benzyl-β-D-arabinofuranoside (4d): β
5.2:1). Rf: 0.5 (hexane/ethyl acetate, 8:2). IR (neat): ν = 3028, 2870,
anomer: [α]D25 = –21.3 (c = 0.3, CH2Cl2). IR (neat): ν = 3030, 2929,
˜
˜
1
1
1751, 1453, 1368, 1225, 1099 cm–1. H NMR (400 MHz, CDCl3): δ =
2865, 1454, 1368, 1095 cm–1. H NMR (400 MHz, CDCl3): δ = 7.32–
7.33–7.24 (m, 30 H, both anomers), 6.03–5.99 (m, 2 H, both ano-
7.24 (m, 15 H), 5.32 (d, J = 5.0 Hz, 1 H), 5.20 (s, 1 H), 4.58–4.54 (m,
Eur. J. Org. Chem. 2016, 579–588
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© 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

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4 H), 4.50–4.46 (m, 2 H), 4.21–4.18 (m, 1 H), 4.00–3.99 (m, 1 H), 3.92–
3.90 (m, 1 H), 3.65–3.48 (m, 3 H), 2.34–2.30 (m, 2 H), 2.02–1.82 (m,
11.0 Hz, 1 H), 3.96 (t, J = 5.4 Hz, 1 H), 3.78–3.72 (m, 1 H), 3.57–3.56
(m, 2 H), 2.10–2.06 (m, 3 H), 1.78–1.52 (m, 12 H) ppm. 13C NMR
5 H), 1.55–0.96 (m, 24 H), 0.89 (d, J = 6.5 Hz, 3 H), 0.86–0.84 (m, 6 (125 MHz, CDCl3): δ = 138.5, 138.2, 138.1, 128.4, 128.3, 128.2, 128.0,
H), 0.66 (s, 3 H) ppm. 13C NMR (125 MHz, CDCl3): δ = 140.8, 138.2,
127.9, 127.8, 127.7, 127.6, 127.4, 99.0, 81.0, 80.2, 78.6, 74.3, 73.2,
138.1, 137.7, 128.4, 128.3, 127.9, 127.8, 127.7, 127.6, 121.7, 104.2, 72.3, 71.9, 42.7, 36.3, 30.7 ppm. HRMS: calcd. for C36H42NaO5 [M +
88.9, 83.6, 80.2, 73.4, 72.1, 72.0, 69.8, 56.8, 56.2, 50.2, 42.4, 40.3, 39.8,
39.6, 37.2, 36.7 36.2, 35.8, 31.9, 29.7, 28.3, 28.1, 27.9, 24.3, 23.9, 22.8,
22.6, 21.1, 19.4, 18.8, 11.9 ppm. HRMS: calcd. for C53H72NaO5 [M +
Na]+ 811.5277; found 811.5276.
Na]+ 577.2930; found 577.2936.
Cholesteryl 2,3,5-Tri-O-benzyl-β-D =
-ribofuranoside (6d): [α]D25
–15.1 (c = 0.4, CH2Cl2). IR (neat): ν = 2934, 2866, 1453, 1364, 1101,
˜
1027 cm–1. 1H NMR (400 MHz, CDCl3): δ = 7.37–7.26 (m, 15 H), 5.31–
5.30 (m, 1 H), 5.15 (s, 1 H), 4.65–4.45 (m, 6 H), 4.31–4.30 (m, 1 H),
4.01–3.99 (m, 1 H), 3.83 (m, 1 H), 3.60 (dd, J = 4.2. 10.4 Hz, 1 H),
3.53–3.44 (m, 2 H), 2.30–1.74 (m, 7 H), 1.59–0.95 (m, 24 H), 0.90 (d,
J = 6.4 Hz, 3 H), 0.87–0.85 (m, 6 H), 0.66 (s, 3 H) ppm. 13C NMR
(125 MHz, CDCl3): δ = 140.5, 138.4, 138.0, 128.5, 128.4, 128.3, 128.0,
4-Penten-1-yl 2,3,5-Tri-O-benzyl-D-lyxofuranoside (α-5b and β-
5b): IR (neat): ν = 3029, 2923, 2871, 1453, 1362, 1089, 1027 cm–1
.
˜
1H NMR (500 MHz, CDCl3): δ = 7.36–7.26 (m, 30 H, both anomers),
5.82–5.74 (m, 2 H, both anomers), 5.01–4.53 (m, 20 H, both ano-
mers), 4.05–4.4.02 (m, 1 H, β anomer), 4.45–3.50 (m, 8 H, both ano-
mers), 3.43–3.41 (m, 1 H, β anomer), 3.36–3.32 (m, 1 H, α anomer), 127.9, 127.8, 127.7, 127.5, 121.9, 121.9, 103.5, 80.3, 78.7, 73.2, 72.4,
3.24–3.21 (m, 1 H, β anomer), 2.17–2.14 (m, 2 H, β anomer), 2.09– 71.7, 56.8, 56.2, 50.2, 42.4, 39.8, 39.6, 38.6, 37.3, 36.8, 36.2, 35.8, 32.0,
2.05 (m, 2 H, α anomer), 1.74–1.71 (m, 2 H, β anomer), 1.65–1.60
(m, 2 H, α anomer) ppm. 13C NMR (125 MHz, CDCl3): δ = 138.7,
138.6, 138.5, 138.3, 138.1, 128.4, 128.3, 128.2, 128.0, 127.8, 127.7,
127.6, 114.9, 114.8, 100.9, 98.9, 79.0, 75.6, 74.9, 74.2, 73.2, 72.8, 72.2,
68.8, 67.3, 61.6, 30.4, 30.4, 29.0, 28.7 ppm. HRMS: calcd. for
29.6, 28.3, 28.1, 24.3, 23.9, 22.9, 22.6, 21.1, 19.4, 18.8, 11.9 ppm.
HRMS: calcd. for C53H72NaO5 [M + Na]+ 811.5277; found 811.5276.
L-Menthyl 2,3,5-Tri-O-benzyl-α-
D =
-xylofuranoside (α-7a): [α]D25
–28.1 (c = 0.4, CH2Cl2). IR (neat): ν = 2952, 2921, 2868, 1454, 1361,
˜
1101, 1029 cm–1 1H NMR (400 MHz, CDCl3): δ = 7.34–7.25 (m, 15
.
C
31H36NaO5 [M + Na]+ 511.2460; found 511.2469.
Adamantanyl 2,3,5-Tri-O-benzyl-α-
-lyxofuranoside (5c): [α]D25
H), 4.92–4.85 (m, 3 H), 4.75–4.62 (m, 4 H), 3.94–3.90 (m, 1 H), 3.70
(t, J = 10.4, Hz, 1 H), 3.61–3.53 (m, 2 H), 3.42 (dd, J = 4.0, 9.8 Hz, 1
H), 3.28 (dt, J = 4.0, 10.4 Hz, 1 H), 2.41–2.39 (m, 1 H), 2.07–2.55 (m,
D
=
+8.17 (c = 0.3, CH Cl ). IR (neat): ν = 3030, 2914, 2852, 1453, 1355,
˜
2
2
1119, 1101 cm–1
.
1H NMR (400 MHz, CDCl3): δ = 7.36–7.24 (m, 15 1 H), 1.62–1.58 (m, 2 H), 1.40–1.24 (m, 2 H), 1.11–0.89 (m, 9 H), 0.69
H), 5.03 (d, J = 3.2 Hz, 1 H), 4.77–4.58 (m, 6 H), 3.88–3.84 (m, 2 H),
(d, J = 6.9 Hz, 3 H) ppm. 13C NMR (125 MHz, CDCl3): δ = 139.0,
3.70–3.67 (m, 2 H), 3.56–3.54 (m, 1 H), 2.08 (br. s, 3 H), 1.72–1.52 (m, 138.5, 138.4, 128.5, 128.4, 128.3, 128.1, 127.9, 127.8, 127.7, 127.6,
12 H) ppm. 13C NMR (125 MHz, CDCl3): δ = 138.9, 138.7, 138.7,
128.4, 128.3, 128.1, 127.8, 127.7, 127.6, 127.5, 91.8, 79.0, 75.3, 74.3,
73.2, 73.1, 72.8, 61.4, 42.9, 36.3, 30.6 ppm. HRMS: calcd. for
98.8, 81.5, 80.8, 80.3, 78.5, 75.6, 73.6, 73.5, 60.3, 48.8, 43.2, 34.3, 31.8,
24.6, 23.0, 22.3, 21.2, 16.1 ppm. HRMS: calcd. for C36H46NaO5 [M +
Na]+ 581.3243; found 581.3240.
C
36H42NaO5 [M + Na]+ 577.2930; found 577.2943.
L-Menthyl 2,3,5-Tri-O-benzyl-β-
D =
-xylofuranoside (β-7a): [α]D25
Cholesteryl 2,3,5-Tri-O-benzyl-
D-lyxofuranoside (α-5d and β-
–19.5 (c = 0.3, CH Cl ). IR (neat): ν = 2925, 2869, 1452, 1356, 1093,
˜
2
2
5d): IR (neat): ν = 3029, 2933, 2866, 1453, 1364, 1093, 1027 cm–1
.
1029 cm–1. 1H NMR (400 MHz, CDCl3): δ = 7.34–7.26 (m, 15 H), 4.91–
4.81 (m, 3 H), 4.71–4.60 (m, 3 H), 4.43 (d, J = 7.4 Hz, 1 H), 3.92 (dd,
J = 5.2, 11.4 Hz, 1 H), 3.62–3.53 (m, 2 H), 3.44 (dt, J = 10.3, 6.3 Hz,
1 H), 3.34–3.30 (m 1 H), 3.20–3.15 (m 1 H), 2.24–2.12 (m, 2 H), 1.65–
1.62 (m, 2 H), 1.36–1.21 (m, 2 H), 0.99–0.83 (m, 9 H), 0.77 (d, J =
6.9 Hz, 3 H) ppm. 13C NMR (125 MHz, CDCl3): δ = 138.6, 138.5, 138.3,
128.5, 128.3, 128.0, 127.9, 127.7, 127.6, 101.3, 84.2, 81.8, 78.1, 77.7,
75.6, 75.0, 73.3, 63.9, 48.1, 40.8, 34.5, 31.5, 25.4, 23.2, 22.3, 21.1,
15.8 ppm. HRMS: calcd. for C36H46NaO5 [M + Na]+ 581.3243; found
581.3250.
˜
1H NMR (500 MHz, CDCl3): δ = 7.36–7.25 (m, 30 H, both anomers),
5.33 (br. s, 2 H, both anomers), 4.68–4.52 (m, 14 H, both anomers),
4.04 (dd, J = 4.6, 12.0 Hz, 1 H, β anomer), 3.93–3.42 (m, 10 H, both
anomers), 4.04 (m, 1 H, β anomer), 2.32–2.21 (m, 4 H, both ano-
mers), 2.01–1.79 (m, 10 H, both anomers), 1.61–0.98 (m, 48 H, both
anomers), 0.89–0.85 (m, 18 H, both anomers), 0.67 (m, 6 H, both
anomers) ppm. 13C NMR (125 MHz, CDCl3): δ = 140.7, 138.8, 138.7,
138.6, 128.4, 128.3, 127.9, 127.8, 127.6, 127.5, 121.8, 96.8, 79.2, 76.0,
75.1, 73.3, 72.8, 61.6, 56.8, 56.2, 50.1, 42.4, 40.0, 39.8, 39.6, 37.1, 36.7,
36.2, 35.8, 31.9, 29.7, 28.3, 28.1, 27.7, 24.3, 23.9, 22.9, 22.6, 21.1, 19.4,
18.8, 11.9 ppm. HRMS: calcd. for C53H72NaO5 [M + Na]+ 811.5277;
found 811.5273.
Adamantanyl 2,3,5-Tri-O-benzyl-β-D-ribofuranoside (α-7c and
β-7c): IR (neat): ν = 3030, 2907, 2851, 1453, 1355, 1072, 1035 cm–1
.
˜
1H NMR (500 MHz, CDCl3): δ = 7.43–7.24 (m, 30 H, both anomers),
5.15 (d, J = 3.4 Hz, 1 H, β-isomer), 4.97–4.61 (m, 13 H, both ano-
mers), 3.92 (t, J = 5.4 Hz, 1 H, β anomer), 3.85 (dd, J = 4.2, 10.4 Hz,
1 H, α anomer), 3.87–3.73 (m, 1 H, β anomer), 3.61–3.54 (m, 4 H,
both anomers), 3.40 (dd, J = 4.2, 9.8 Hz, 1 H, β anomer), 3.34–3.31
4-Penten-1-yl 2,3,5-Tri-O-benzyl-D-ribofuranoside (α-6b and β-
6b): IR (neat): ν = 3029, 2921, 2864, 1453, 1364, 1108, 1027 cm–1
.
˜
1H NMR (500 MHz, CDCl3): δ = 7.39–7.23 (m, 30 H, both anomers),
5.88–5.74 (m, 2 H, both anomers), 5.02–4.97 (m, 4 H, both anomers),
4.71–4.41 (m, 12 H, both anomers), 4.33–4.34 (m, 1 H, β anomer), (m, 1 H, α anomer), 3.18–3.13 (m, 1 H, α anomer), 2.14 (br. s, 6 H,
4.24 (dd, J = 4.0, 8.0 Hz, 1 H, α anomer), 4.04–3.34 (m, 14 H, both
anomers), 2.18–2.02 (m, 4 H, both anomers), 1.81–1.57 (m, 4 H, both
anomers) ppm. 13C NMR (125 MHz, CDCl3): δ = 138.5, 138.4, 138.2,
both anomers), 1.89–1.58 (m, 24 H, both anomers) ppm. 13C NMR
(125 MHz, CDCl3): δ = 139.2, 138.8, 138.7, 138.5, 128.5, 128.3, 128.2,
128.1, 128.0, 127.9, 127.8, 127.7, 127.6, 127.5, 96.8, 90.0, 84.3, 82.1,
138.0, 137.9, 128.5, 128.4, 128.3, 128.2, 128.1, 127.9, 127.8, 127.7, 81.5, 79.9, 78.7, 78.0, 75.7, 75.6, 75.2, 74.4, 73.6, 73.4, 73.1, 63.7, 59.7,
127.6, 127.6, 127.4, 114.8, 114.7, 105.4, 101.4, 81.6, 80.4, 79.9, 78.6,
75.4, 73.5, 72.5, 72.3, 71.5, 70.1, 67.8, 67.3, 30.4, 30.3, 28.9, 28.7 ppm.
HRMS: calcd. for C31H36NaO5 [M + Na]+ 511.2460; found 511.2465.
42.8, 42.5, 36.3, 30.7 ppm. HRMS: calcd. for C36H46NaO5 [M + NH4]+
572.3376; found 572.3381; calcd. for C36H42NaO5 [M + Na]+
577.2930; found 577.2938.
Adamantanyl 2,3,5-Tri-O-benzyl-β-
D
-ribofuranoside (6c): [α]D25
=
Cholesteryl 2,3,5-Tri-O-benzyl-D-xylofuranoside (α-7d and β-
–10.13 (c = 0.3, CH2Cl2), IR (neat): ν = 3029, 2907, 2851, 1453, 1355, 7d): IR (neat): ν = 3030, 2933, 2866, 1453, 1364, 1073, 1028 cm–1
.
˜
˜
1095, 1059 cm–1
H), 5.41 (d, J = 2.3 Hz, 1 H), 4.67–4.48 (m, 6 H), 4.27 (dd, J = 5.0,
.
1H NMR (400 MHz, CDCl3): δ = 7.43–7.24 (m, 15 1H NMR (400 MHz, CDCl3): δ = 7.35–7.24 (m, 30 H, both anomers),
5.33–5.302 (m, 2 H, both anomers), 4.91–4.41 (both anomers, m 12
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Eur. J. Org. Chem. 2016, 579–588
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Full Paper
H), 3.93–312 (m, 12 H, both anomers), 2.48–2.24 (m, 4 H, both ano-
mers), 2.03–1.77 (m, 10 H, both anomers), 1.59–0.97 (m, 50 H, both
7.18 (m, 15 H), 4.93 (dd, J = 8.2, 10.0 Hz, 1 H), 4.79 (d, J = 5.4 Hz, 1
H), 4.76 (d, J = 5.4 Hz, 1 H), 4.67–4.53 (m, 5 H), 3.75–3.57 (m, 4 H),
anomers), 0.93–0.84 (m, 18 H, both anomers), 0.66 (s, 6 H, both 3.46–3.45 (m, 1 H), 2.11 (br. s, 3 H), 1.95 (s, 3 H), 1.84–1.55 (m, 12
anomers) ppm. 13C NMR (125 MHz, CDCl3): δ = 140.9, 140.6, 139.1, H) ppm. 13C NMR (125 MHz, CDCl3): δ = 169.4, 138.4, 138.3, 138.0,
138.8, 138.6, 138.4, 138.2, 128.5, 128.4, 128.2, 128.1, 128.0, 127.9, 128.5, 128.3, 128.1, 127.9, 127.7, 127.6, 127.5, 94.0, 83.3, 78.3, 75.0,
127.7, 127.6, 122.0, 121.8, 102.7, 94.7, 84.0, 82.1, 81.5, 79.7, 79.5,
78.4, 77.9, 76.4, 75.8, 75.7, 75.1, 73.6, 73.4, 73.2, 63.9, 60.1, 56.8, 56.2,
50.2, 42.4, 39.9, 39.8, 39.6, 39.1, 37.4, 37.2, 36.9, 36.8, 36.2, 35.8, 32.0,
31.9, 30.0, 28.3, 28.1, 27.5, 24.3, 23.9, 22.9, 22.6, 21.1, 19.5, 18.8,
11.9 ppm. HRMS: calcd. for C53H72NaO5 [M + Na]+ 811.5277; found
811.5272.
74.9, 73.5, 73.4, 69.3, 42.5, 36.2, 30.6, 21.1 ppm. HRMS: calcd. for
C39H46NaO7 [M + Na]+ 649.3141; found 649.3144.
Methyl
(1→6)-2,3,4-tri-O-benzoyl-α-
+20.1 (c = 0.5, CH Cl ). IR (neat): ν = 2924, 2854, 1730, 1452, 1279,
2-O-Acetyl-3,4,6-tri-O-benzyl-β-
D-glucoctopyranosyl-
D
-glucopyranoside (12f): [α]D25
=
˜
2
1
2
1068, 1094 cm–1. H NMR (400 MHz, CDCl3): δ = 7.97–7.82 (m, 6 H),
7.51–7.15 (m, 24), 6.12 (t, J = 9.4 Hz, 1 H), 5.39 (t, J = 9.6 Hz, 1 H),
5.22–5.17 (m, 2 H), 5.04–5.00 (m, 1 H), 4.79–4.74 (m, 2 H), 4.66 (d,
J = 11.0 Hz, 1 H), 4.53–4.39 (m, 4 H), 4.26–4.22 (m, 1 H), 4.04 (d, J =
11.0 Hz, 1 H), 3.69–3.55 (m, 5 H), 3.45–3.42 (m, 1 H), 3.38 (s, 3 H),
1.97 (s, 3 H) ppm. 13C NMR (125 MHz, CDCl3): δ = 169.6, 165.8, 165.4,
138.2, 138.1, 138.0, 133.5, 133.1, 130.0, 129.9, 129.7, 129.3, 128.9,
128.5, 128.4, 128.3, 128.0, 127.9, 127.7, 127.6, 101.4, 96.7, 82.9, 77.9,
75.2, 75.1, 73.5, 73.1, 72.2, 70.6, 69.6, 68.7, 68.5, 68.4, 55.4, 21.0 ppm.
HRMS: calcd. for C57H60NO15 [M + NH4]+ 998.3963; found 998.3971.
Methyl
2,3,5-Tri-O-benzyl-
D
-xylofuranosyl-(1→4)-2,3,6-tri-O-
benzyl-α-
D-glucopyranoside (7g): IR (neat): ν = 3030, 2905, 1496,
˜
1
1453, 1360, 1159, 1092, 1028 cm–1. H NMR (500 MHz, CDCl3): δ =
7.42–7.22 (m, 30 H, both anomers), 5.60–5.59 (d, J = 3.4 Hz, 1 H, β
anomer), 5.01–5.00 (d, J = 3.1 Hz, 1 H, α anomer), 4.97–4.84 (m, 4
H, both anomers), 4.78–4.56 (m, 10 H, both anomers), 4.38–4.27 (m,
1 H, both anomers), 4.10–3.87 (m, 2 H, both anomers), 3.84–3.68
(m, 2 H, both anomers), 3.62–3.42 (m, 4 H, both anomers), 3.41 (s,
3 H, one anomer), 3.39 (s, 3 H, one anomer), 3.32–3.38 (m, 1 H, one
anomer), 3.0–2.96 (m, 1 H, one anomer) ppm. 13C NMR (100 MHz,
CDCl3): δ = 139.0, 138.9, 138.8, 138.7, 138.6, 138.5, 138.4, 138.3,
138.1, 138.0, 137.9, 128.7, 128.6, 128.5, 128.4, 128.3, 128.2, 128.0,
127.9, 127.8, 127.7, 127.6, 127.5, 127.4, 126.9, 104.9, 104.8, 103.2,
98.6, 97.9, 96.4, 84.2, 84.1, 83.8, 82.6, 82.0, 81.9, 81.8, 81.3, 81.2, 80.3,
79.2, 79.0, 78.2, 78.1, 78.0, 77.7, 77.3, 76.0, 75.8, 75.7, 75.6, 75.4, 75.2,
74.8, 74.7, 74.4, 73.8, 73.7, 73.6, 73.4, 73.3, 73.2, 72.0, 70.4, 70.2,
69.4, 69.1, 67.8, 63.7, 61.0, 57.2, 55.5, 55.3 ppm. HRMS: calcd. for
L
-Menthyl 2-O-Acetyl-3,4,6-tri-O-benzyl-α-D-galactopyranoside
(13a): [α]D25 = –27.1 (c = 0.5, CH2Cl2). IR (neat): ν = 3030, 2952, 2921,
˜
2868, 1752, 1454, 1368, 1234, 1072 cm–1. 1H NMR (500 MHz, CDCl3):
δ = 7.35–7.22 (m, 15 H), 5.25 (dd, J = 8.0, 10.0 Hz, 1 H), 4.92 (d, J =
11.4 Hz, 1 H), 4.64 (d, J = 12.0 Hz, 1 H), 4.60 (d, J = 12.0, 8.2 Hz, 1
H), 4.52–4.32 (m, 4 H), 3.91–3.88 (m 1 H), 3.62–3.48 (m, 3 H), 3.32
(td, J = 4.0, 10.8 Hz, 1 H), 2.32–2.30 (m, 1 H), 2.01 (s, 3 H), 1.93–1.89
(m, 1 H), 1.65–1.58 (m, 3 H), 1.29–1.14 (m, 2 H), 0.91–0.69 (m, 9 H),
0.70 (d, J = 6.9 Hz, 3 H) ppm. 13C NMR (125 MHz, CDCl3): δ = 169.5,
138.6, 138.2, 138.0, 128.5, 128.4, 128.3, 128.2, 128.0, 127.8, 127.7,
127.6, 127.5, 99.9, 80.7, 78.9, 74.4, 73.6, 72.9, 72.0, 71.7, 69.2, 47.5,
41.1, 34.3, 31.5, 24.7, 22.9, 22.4, 21.1, 15.5 ppm. HRMS: calcd. for
C
54H62NO10 [M + NH4]+ 884.4374; found 884.4373.
Methyl
2,3,5-Tri-O-benzyl-
D
-xylofuranosyl-(1→3)-2,4,6-tri-O-
benzyl-α-
D-glucopyranoside (7h): IR (neat): ν = 3030, 2923, 1496,
˜
1
1453, 1361, 1207, 1071, 1028 cm–1. H NMR (500 MHz, CDCl3): δ =
7.42–7.17 (m, 30 H, both anomers), 5.49 (d, J = 3.4 Hz, 1 H, β ano-
mer), 5.02 (d, J = 11.4 Hz, 1 H, one anomer), 4.99 (d, J = 3.2 Hz, 1
H, α anomer), 4.96 (d, J = 8.0 Hz, 1 H, one anomer), 4.94–4.81 (m, 3
H, both anomers), 4.75–4.38 (m, 10 H, both anomers), 4.34–4.24 (m,
1 H, both anomers), 4.15–4.00 (m, 1 H, both anomers), 3.93–3.89
(m, 1 H, both anomers), 3.81–3.66 (m, 2 H, both anomers), 3.64–
3.46 (m, 4 H, both anomers), 3.41–3.38 (m, 1 H, one anomer), 3.44
(s, 3 H, one anomer), 3.31 (s, 3 H, one anomer), 3.19–3.15 (m, 1 H,
one anomer) ppm. 13C NMR (125 MHz, CDCl3): δ = 139.0, 138.9,
138.8, 138.7, 138.6, 138.5, 138.4, 138.3, 138.2, 138.1, 138.0, 137.9,
128.8, 128.7, 128.6, 128.5, 128.4, 128.3, 128.2, 128.1, 128.0, 127.9,
127.8, 127.7, 127.6, 127.5, 127.4, 127.0, 103.3, 98.1, 98.0, 97.7, 97.4,
84.3, 83.0, 81.5, 81.0, 79.6, 79.4, 78.9, 78.7, 78.4, 78.2, 77.7, 77.6, 76.1,
76.0, 75.8, 75.7, 75.1, 75.0, 74.8, 74.6, 73.8, 73.7, 73.6, 73.4, 73.3, 73.2,
69.7, 68.6, 68.5, 63.8, 60.5, 55.3, 55.2, 55.1 ppm. HRMS: calcd. for
C54H62NO10 [M + NH4]+ 884.4374; found 884.4378.
C
39H54NO7 [M + NH4]+ 648.3900; found 648.3907.
4-Penten-1-yl 2-O-Acetyl-2,3,6-tri-O-benzyl-β-
D
-galactopyran-
˜
oside (13b): [α]D25 = –7.3 (c = 0.1, CH Cl ). IR (neat): ν = 2922, 2869,
2
2
1
1748, 1453, 1367, 1233, 1070 cm–1. H NMR (400 MHz, CDCl3): δ =
7.35–7.23 (m, 15 H), 5.81–5.71 (m, 1 H), 5.34 (dd, J = 8.2, 10.0 Hz, 1
H), 5.02–4.91 (m, 3 H), 4.66 (d, J = 12.2 Hz, 1 H), 4.57 (d, J = 12.2 Hz,
1 H), 4.51–4.39 (m, 3 H), 4.30 (d, J = 8.2 Hz, 1 H), 3.94–3.92 (m 1 H),
3.88–3.80 (m, 1 H), 3.64–3.34 (m, 5 H), 2.07–2.03 (m. 2 H), 2.01 (s, 3
H), 1.66–1.58 (m, 2 H) ppm. 13C NMR (125 MHz, CDCl3): δ = 169.6,
138.5, 138.2, 138.0, 137.9, 128.5, 128.3, 128.2, 128.0, 127.9, 127.8,
127.6, 127.5, 114.8, 101.4, 80.3, 74.4, 73.6, 72.5, 71.9, 71.4, 68.7, 30.0,
28.7, 21.1 ppm. HRMS: calcd. for C34H44NO7 [M + NH4]+ 578.3118;
found 578.3118.
Adamantyl 2-O-Acetyl-3,4,6-tri-O-benzyl-β-D-galactopyranos-
ide (13c): [α]D25 = +14.2 (c = 0.4, CH2Cl2). IR (neat): ν = 3030, 2911,
˜
2850, 1749, 1453, 1353, 1234, 1067 cm–1. 1H NMR (400 MHz, CDCl3):
δ = 7.35–7.22 (m, 15 H), 5.27 (dd, J = 8.2, 10.0 Hz, 1 H), 4.91 (d, J =
12.2 Hz, 1 H), 4.66–4.38 (m, 6 H), 3.91 (s, 1 H), 3.64–3.49 (m, 4 H),
2.09 (br. s, 3 H), 2.01 (s, 3 H), 1.81–1.53 (m, 12 H) ppm. 13C NMR
(125 MHz, CDCl3): δ = 169.4, 138.6, 138.2, 138.0, 128.5, 128.4, 128.2,
127.9, 127.8, 127.7, 127.5, 94.4, 80.7, 74.7, 74.3, 73.6, 73.4, 72.5, 71.9,
69.2, 42.5, 36.3, 30.6, 21.5 ppm. HRMS: calcd. for C39H50NO7 [M +
NH4]+ 644.3587; found 644.3588.
4-Penten-1-yl 2-O-Acetyl-2,3,6-tri-O-benzyl-β-
D-glucopyranos-
˜
ide (12b): [α]D25 = –5.1 (c = 0.3, CH Cl ). IR (neat): ν = 2923, 2869,
2
1
2
1749, 1458, 1368, 1234, 1071 cm–1. H NMR (400 MHz, CDCl3): δ =
7.32–7.15 (m, 15 H), 5.80–5.72 (m, 1 H), 5.01–4.93 (m, 3 H), 4.79 (d,
J = 8.2 Hz, 1 H), 4.76 (d, J = 8.2 Hz, 1 H), 4.67–4.52 (m, 4 H), 4.32 (d,
J = 8.2 Hz, 1 H), 3.89–3.84 (m, 1 H), 3.5–3.63 (m, 4 H), 3.48–3.41 (m,
2 H), 2.08–2.04 (m, 2 H), 1.94 (s, 3 H), 1.66–1.56 (m, 2 H) ppm. 13C
NMR (125 MHz, CDCl3): δ = 169.5, 138.2, 138.1, 130.0, 128.5, 128.4,
128.1, 127.9, 127.8, 127.6, 114.9, 101.0, 83.0, 78.1, 75.2, 75.0, 73.6,
73.2, 68.9, 30.0, 28.8, 20.9 ppm. HRMS: calcd. for C34H44NO7 [M +
NH4]+ 578.3118; found 578.3115.
Cholesteryl 2-O-Acetyl-3,4,6-tri-O-benzyl-β-D-galactopyranos-
ide (13d): [α]D25 = –8.0 (c = 0.5, CH Cl ). IR (neat): ν = 3030, 2930,
˜
2
2
2850, 1742, 1454, 1367, 1235, 1071 cm–1. 1H NMR (500 MHz, CDCl3):
Adamantyl 2-O-Acetyl-3,4,6-tri-O-benzyl-β-
D
-glucopyranoside
δ = 7.33–7.25 (m, 15 H), 5.30–5.28 (m, 3 H), 4.92–4.90 (m, 1 H), 4.64
(12c): [α]D25 = +4.1 (c = 0.4, CH Cl ). IR (neat): ν = 3030, 2907, 2852, (d, J = 12.4 Hz, 1 H), 5.58 (d, J = 12.4 Hz, 1 H), 4.50–4.38 (m, 4 H),
˜
2
1
2
1749, 1453, 1355, 1075 cm–1. H NMR (400 MHz, CDCl3): δ = 7.33– 3.92 (s, 1 H), 3.61–3.42 (m, 4 H), 2.21–1.78 (m, 9 H), 1.53–0.92 (m,
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25 H), 0.91–0.85 (m, 9 H), 0.65 (s, 3 H) ppm. 13C NMR (125 MHz, H), 4.02–3.99 (m, 1 H), 3.89–3.80 (m 3 H), 3.69 (d, J = 10.4 Hz, 1 H),
CDCl3): δ = 170.1, 138.6, 138.2, 138.0, 128.5, 128.4, 128.3, 128.2,
127.9, 127.7, 127.6, 127.5, 121.8, 104.0, 82.1, 74.6, 73.6, 72.1, 72.0,
71.0, 60.4, 56.8, 56.2, 50.2, 42.3, 39.8, 39.5, 37.3, 36.8, 36.2, 35.8, 32.0,
29.7, 29.5, 28.3, 28.0, 24.3, 23.8, 22.9, 22.6, 21.1, 20.9, 18.7, 11.9 ppm.
HRMS: calcd. for C56H80NO7 [M + NH4]+ 878.5935; found 878.5944.
3.43–3.50 (m, 1 H), 2.30–2.26 (m, 2 H), 2.13 (s, 3 H), 2.03–1.9 (m, 4
H), 1.59–1.22 (m, 15 H), 1.18–0.93 (m, 10 H), 0.89 (d, J = 6.4 Hz, 3
H), 0.86–0.84 (m 6 H), 0.65 (s, 3 H) ppm. 13C NMR (125 MHz, CDCl3):
δ = 170.7, 149.6, 138.4, 138.3, 138.1, 128.4, 128.3, 128.1, 128.0, 127.9,
127.7, 127.6, 122.0, 95.8, 78.4, 75.3, 74.5, 73.4, 71.8, 71.3, 69.3, 68.9,
56.8, 56.2, 50.1, 42.3, 39.9, 39.6, 37.0, 36.7, 36.2, 35.8, 32.0, 28.3, 28.1,
27.7, 24.3, 23.9, 22.9, 22.6, 21.3, 21.1, 19.4, 18.8, 11.9 ppm. HRMS:
calcd. for C56H80NO7 [M + NH4]+ 878.5935; found 878.5939.
Methyl
2-O-Acetyl-3,4,6-tri-O-benzyl-α-
D-galactopyranosyl-
(1→6)-2,3,4-tri-O-benzoyl-α-
D
-glucopyranoside (13f): [α]D25
=
+24.7 (c = 0.4, CH2Cl2). IR (neat): ν = 3063, 2924, 2854, 1730, 1452,
˜
1
1279, 1069 cm–1. H NMR (500 MHz, CDCl3): δ = 7.97–7.83 (m, 6 H),
Methyl
(1→6)-2,3,4-tri-O-benzyl-α-
+13.1 (c = 0.1, CH Cl ). IR (neat): ν = 3030, 2924, 2854, 1745, 1454,
2-O-Acetyl-3,4,6-tri-O-benzyl-α-
D-glucopyranosyl-
D
-glucopyranoside (14e): [α]D25
=
7.50–7.20 (m, 24), 6.10 (t, J = 9.7 Hz, 1 H), 5.40–5.35 (m, 2 H), 5.21–
5.16 (m, 2 H), 4.89 (d, J = 11.6 Hz, 1 H), 4.65 (d, J = 11.6 Hz, 1 H),
4.54–4.49 (m, 2 H), 4.40–4.22 (m, 4 H), 4.01 (d, J = 10.9 Hz, 1 H),
3.91–3.90 (m, 1 H), 3.62 (dd, J = 8.0, 10.9 Hz, 1 H), 3.52–3.48 (m, 4
H), 3.41 (s, 3 H), 2.15 (3 H) ppm. 13C NMR (125 MHz, CDCl3): δ =
169.6, 165.7, 165.5, 138.5, 138.0, 137.8, 133.4, 133.1, 130.0, 129.9,
129.7, 128.5, 128.4, 128.3, 128.2, 127.9, 127.8, 127.5, 101.7, 96.6, 80.2,
74.5, 73.6, 73.5, 72.5, 72.2, 72.0, 71.2, 70.7, 69.6, 68.7, 68.4, 68.0, 55.4,
21.0 ppm. HRMS: calcd. for C57H60NO15 [M + NH4]+ 998.3963; found
998.3970.
˜
2
2
1235, 1091 cm–1 1H NMR (500 MHz, CDCl3): δ = 7.37–7.10 (m, 30
.
H), 5.39–5.38 (m, 1 H), 4.99–4.79 (m, 6 H), 4.69–4.38 (m, 8 H), 3.99–
3.39 (m, 11 H), 3.30 (s, 3 H), 2.12 (s, 3 H) ppm. 13C NMR (125 MHz,
CDCl3): δ = 170.4, 139.2, 138.6, 138.2, 137.8, 128.5, 128.4, 128.3,
128.2, 128.1, 128.0, 127.8, 127.7, 98.0, 97.8, 82.1, 80.1, 77.7, 75.8,
75.1, 75.0, 74.2, 73.4, 71.6, 71.5, 69.7, 68.7, 68.5, 66.1, 55.1, 21.2 ppm.
HRMS: calcd. for C57H66NO12 [M + NH4]+ 956.4585; found 956.4598.
Methyl
(1→6)-2,3,4-tri-O-benzoyl-α-
+69.9 (c = 0.3, CH Cl ). IR (neat): ν = 3063, 2924, 2854, 1732, 1452,
2-O-Acetyl-3,4,6-tri-O-benzyl-α-
D-glucopyranosyl-
D
-glucopyranoside (14f): [α]D25
=
L
-Menthyl
2-O-Acetyl-3,4,6-tri-O-benzyl-α-D-glucopyranoside
(14a): [α]D25 = –34.9 (c = 0.3, CH2Cl2). IR (neat): ν = 3030, 2954, 2923,
˜
2
1
2
˜
1279, 1069 cm–1. H NMR (400 MHz, CDCl3): δ = 7.98–7.84 (m, 6 H),
7.50–7.13 (m, 24), 6.11 (t, J = 9.8 Hz, 1 H), 5.54 (t, J = 9.8 Hz, 1 H),
5.31–5.30 (m, 1 H), 5.24 (dd, J = 3.6, 10.3 Hz, 1 H), 5.18 (d, J = 3.6 Hz,
1 H), 4.85–4.81 (m, 2 H), 4.58–4.55 (m, 2 H), 4.43–4.35 (m, 3 H), 4.20–
4.16 (m, 1 H), 3.94–3.81 (m 3 H), 3.71–3.59 (m, 3 H), 3.52–3.49 (m, 1
H), 3.37 (s, 3 H), 2.11 (s, 3 H) ppm. 13C NMR (125 MHz, CDCl3): δ =
170.4, 165.9, 165.2, 138.6, 138.2, 138.0, 133.5, 133.4, 130.0, 129.7,
128.6, 128.4, 128.3, 128.2, 127.9, 127.8, 127.7, 127.6, 97.9, 96.9, 77.9,
75.1, 74.2, 73.4, 73.4, 72.1, 71.8, 71.5, 70.5, 69.7, 68.7, 68.6, 68.1, 66.3,
55.5, 21.1 ppm. HRMS: calcd. for C57H60NO15 [M + NH4]+ 998.3963;
found 998.3969.
2868, 1744, 1454, 1370, 1236, 1080 cm–1. 1H NMR (400 MHz, CDCl3):
δ = 7.35–7.13 (m, 15 H), 5.24–5.23 (m, 1 H), 4.90–4.83 (m, 2 H), 4.70–
4.66 (m, 2 H), 4.56–4.43 (m, 3 H), 3.98–3.92 (m, 2 H), 3.88–3.78 (m,
2 H), 3.67 (dd, J = 2.0, 10.7 Hz, 1 H), 3.32 (td, J = 4.3, 10.7 Hz, 1 H),
2.13 (s, 3 H), 2.02–2.00 (m, 1 H), 1.60–1.53 (m, 2 H), 1.34–1.12 (m, 3
H), 0.99–0.69 (m, 9 H), 0.75 (d, J = 6.9 Hz, 3 H) ppm. 13C NMR
(125 MHz, CDCl3): δ = 170.0, 138.5, 138.5, 138.0, 128.4, 128.3, 128.2,
128.0, 127.8, 127.7, 127.6, 99.3, 81.7, 78.0, 75.2, 74.7, 73.4, 71.8, 71.5,
69.4, 69.1, 48.5, 42.7, 34.3, 31.6, 25.9, 23.3, 22.2, 21.2, 21.1, 16.3 ppm.
HRMS: calcd. for C39H54NO7 [M + NH4]+ 648.3900; found 648.3904.
4-Penten-1-yl 2-O-Acetyl-2,3,6-tri-O-benzyl-α-D-glucopyranos-
Supporting Information (see footnote on the first page of this
article): Copies of the 1H and 13C NMR spectra of selected com-
pounds.
ide (14b): [α]D25 = +40.8 (c = 0.2, CH2Cl2). IR (neat): ν = 3030, 2923,
˜
1
1744, 1453, 1369, 1235, 1027 cm–1. H NMR (400 MHz, CDCl3): δ =
7.35–7.12 (m, 15 H), 5.82–5.73 (m, 1 H), 5.34–5.33 (m, 1 H), 5.02–
4.93 (m, 2 H), 4.85–4.80 (m, 2 H), 4.71–4.65 (m, 2 H), 4.54–4.47 (m,
3 H), 9.97 (dd, J = 3.2, 9.2 Hz, 1 H), 3.86 (t, J = 9.4 Hz, 1 H), 3.79–
3.76 (m, 2 H), 3.69–3.64 (m, 2 H), 3.42–3.38 (m, 1 H), 2.13 (s, 3 H),
2.10–19.8 (m, 2 H), 1.67–1.61 (m, 2 H) ppm. 13C NMR (125 MHz,
Acknowledgments
The authors thank the Department of Science and Technology
CDCl3): δ = 170.6, 138.4, 138.3, 138.0, 128.4, 128.1, 128.0, 127.8, (DST), New Delhi, for the J. C. Bose National Fellowship to
127.6, 115.0, 97.8, 97.8, 78.3, 75.3, 74.4, 73.5, 71.8, 71.4, 68.9, 67.3,
30.3, 28.6, 21.2 ppm. HRMS: calcd. for C34H44NO7 [M + NH4]+
578.3118; found 578.3121.
Y. D. V. (JCB/SR/S2/JCB-26/2010) and the Council of Scientific
and Industrial Research (CSIR), New Delhi, for financial support
(grant number 02(0124)/13/EMR-II). A. M. thanks the Council of
Scientific and Industrial Research, and R. P. and R. R. thank the
University Grants Commission (UGC), New Delhi for senior re-
search fellowships.
Adamantyl 2-O-Acetyl-3,4,6-tri-O-benzyl-α-
D-glucopyranoside
(14c): [α]D25 = +13.1 (c = 0.1, CH Cl ). IR (neat): ν = 2908, 2852, 1743,
˜
2
2
1
1453, 1369, 1236, 1060 cm–1. H NMR (400 MHz, CDCl3): δ = 7.35–
7.13 (m, 15 H), 5.25 (d, J = 1.9 Hz, 1 H), 5.17–5.16 (m, 1 H), 4.84 (d,
J = 10.9 Hz, 1 H), 4.70–4.68 (m, 2 H), 4.51 (d, J = 10.9 Hz, 1 H), 4.48–
4.44 (m, 2 H), 4.05–3.98 (m, 2 H), 3.91–3.79 (m, 2 H), 3.66 (dd, J =
2.0, 10.5 Hz, 1 H), 2.19 (s, 3 H), 2.10 (br. s, 3 H), 1.77–1.53 (m, 12 H)
ppm. 13C NMR (125 MHz, CDCl3): δ = 170.8, 138.5, 138.4, 138.2,
128.4, 128.3, 128.1, 128.0, 127.8, 127.7, 127.5, 91.0, 78.3, 75.3, 75.1,
74.7, 73.4, 71.8, 70.9, 70.5, 69.1, 42.3, 36.3, 30.6, 21.3 ppm. HRMS:
calcd. for C39H50NO7 [M + Na]+ 644.3587; found 644.3591 and
C39H46NaO7 [M + Na]+ 649.3141; found 649.3127.
Keywords: Homogeneous catalysis · Gold · Alkynes ·
Carbohydrates · Glycosylation
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Received: September 29, 2015
Published Online: December 2, 2015
Eur. J. Org. Chem. 2016, 579–588
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