Synthesis of O- and C-glycosides derived from β-(1,3)-d-glucans

Article abstract of DOI:10.1016/j.carres.2013.07.007

A series of β-(1,3)-d-glucans have been synthesized incorporating structural variations specifically on the reducing end of the oligomers. Both O- and C-glucosides derived from di- and trisaccharides have been obtained in good overall yields and with comp

Full text of DOI:10.1016/j.carres.2013.07.007

Carbohydrate Research 382 (2013) 9–18
Contents lists available at ScienceDirect
Carbohydrate Research
journal homepage: www.elsevier.com/locate/carres
Synthesis of O- and C-glycosides derived from b-(1,3)-D-glucans
Eduardo Marca a, Jessika Valero-Gonzalez b, Ignacio Delso a,c, Tomás Tejero a, Ramon Hurtado-Guerrero b,d
,
Pedro Merino a,
⇑
a Laboratorio de Síntesis Asimétrica, Departamento de Síntesis y Estructura de Biomoléculas, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), Universidad de Zaragoza,
CSIC, 50009 Zaragoza, Aragón, Spain
b Instituto de Biocomputación y Fisica de Sistemas Complejos (BIFI), BIFI-IQFR (CSIC) Joint Unit, Universidad de Zaragoza, 50009 Zaragoza, Aragón, Spain
c Servicio de Resonancia Magnética Nuclear, Centro de Química y Materiales de Aragón(CEQMA), Universidad de Zaragoza, CSIC, Campus San Francisco, 50009 Zaragoza, Aragón, Spain
d Fundación ARAID, Gobierno de Aragón, Zaragoza, Spain
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 18 June 2013
Received in revised form 19 July 2013
Accepted 21 July 2013
Available online 30 July 2013
A series of b-(1,3)-D-glucans have been synthesized incorporating structural variations specifically on the
reducing end of the oligomers. Both O- and C-glucosides derived from di- and trisaccharides have been
obtained in good overall yields and with complete selectivity. Whereas the O-glycosides were obtained
via a classical Koenigs–Knorr glycosylation, the corresponding C-glycosides were obtained through ally-
lation of the anomeric carbon and further cross-metathesis reaction. Finally, the compounds were eval-
uated against two glycosidases and two endo-glucanases and no inhibitory activity was observed.
Ó 2013 Elsevier Ltd. All rights reserved.
Keywords:
Laminaribiose
Laminaritriose
Laminarans
Glucans
Fungal infections
1. Introduction
in fungal cell wall assembly and rearrangement.7 These enzymes
are classified as GH72 family in the CAZy database and are named
Fungal cells possess a thick cell-wall mainly constituted by a
differently depending on the organism from which they come
from.8 These proteins have been also shown to be essential in
organisms like Aspergillus fumigatus and Schizosaccharomyces
linear chain of b-(1,3)-D-glucan linked to chitin via b-(1,4) linkage
with ca. 3–4% of interchain b-(1,6) glucosidic bonds (Fig. 1).1 Syn-
thesis, degradation, and remodeling of polysaccharides forming the
fungal cell wall are dynamic processes important for growth, bud-
ding, branching, or cell lysis.2 The major component of the cell
wall, b-(1,3)-D-glucan 1 units, are not present in human cells, and
therefore the enzymes responsible for the synthesis and remodel-
ing of fungal cell walls are suitable targets for the treatment of fun-
CHITIN
O
HO
gal infections. Among these enzymes b-(1,3)-
2.4.1.34), that makes b-(1,3)- -glucan from UDP-
of the best drug targets.3 Indeed, b-(1,3)-
-glucan synthase inhibi-
D
-glucan synthase (EC
OH
D
D-glucose, is one
O
HO
O
OH
D
O
AcHN
OH
O
HO
HO
β-1,6
tors have shown promising biological activities for the treatment of
OH
OH
β-1,4
important fungal infections such as Candidiasis and Aspergillosis.4
O
O
O
O
O
HO
O
HO
In addition to b-(1,3)-
active role in the metabolism of b-(1,3)-
the activities of three endo-b-(1,3) glucanases that exclusively
hydrolyze linear b-(1,3)-
-glucans have been recently studied.6
-transglycosylases are also important enzymes
D
-glucan synthase, glucanases play an
O
O
O
O
-glucans.5 In this context,
HO
HO
HO
HO
D
β-1,3
β-1,3
D
OH
OH
OH
Similarly, b-(1,3)-
D
O
O
HO
O
HO
HO
HO
OH
O
O
HO
HO
HO
⇑
n
Corresponding author. Tel.: +34 876553783.
E-mail addresses: emarca@unizar.es (E. Marca), jvalero@bifi.es (J. Valero-Gonzalez),
idelso@unizar.es (I. Delso), ttejero@unizar.es (T. Tejero), rhurtado@bifi.es
(R. Hurtado-Guerrero), pmerino@unizar.es (P. Merino).
1
Figure 1. b-(1,3)-D-Glucans in the fungal cell wall.
0008-6215/$ - see front matter Ó 2013 Elsevier Ltd. All rights reserved.
http://dx.doi.org/10.1016/j.carres.2013.07.007

10
E. Marca et al. / Carbohydrate Research 382 (2013) 9–18
In this paper we report an efficient synthesis of a variety of
OH
OH
O- and C-glycosides related to laminaribiose and laminaritriose
of general formula A (Scheme 1). The glycosides contain hydropho-
bic units at the reducing end of the oligosaccharides. The presence
of a hydrophobic pocket in GH+1 subsite is well-known and it is
admitted that additional mimicking of the transition state is
required for inhibiting these enzymes.17 However, in the case of
compounds A the presence of additional carbohydrate units linked
by 1,3-bonds can help to the recognition by the enzyme thus
facilitating the interaction of the hydrophobic residue. Modified
O
O
HO
HO
O
O
O
R
H
HO
HO
n
O
2
n = 4
n = 1
R =
m = 1, 2
m
OH
b-(1,3)-D-glucans A could also provide crucial information regard-
HO
3
R =
R =
O
ing the mechanism of action of the above mentioned enzymes, par-
ticularly transglycosylases which also have a hydrophobic pocket
suitable of interacting with hydrophobic results.8 Biological tests
with a series of glycosidases and endo-glucanases are also reported.
NH
O
O
4
5
n = 4
2. Results and discussion
S
n = 2, 5 R =
In principle, two approaches are possible for the synthesis of
1-O- and 1-C-glycosides A. Glycosylation of B with a suitable deriv-
ative C, in which the desired unit has been incorporated into the
anomeric center could be considered a convergent approach
(Scheme 1). Compound C should be prepared by the corresponding
NH2
D-glucans.
Figure 2. O-Glycoside analogues of b-(1,3)-
pombe suggesting that the development of inhibitors against them
O- and C-glycosylation procedures from a D-glucose derivative D
might be a new approach to tackle fungal diseases.9
(n = 0, R0 = protecting group). This route, however, involves the reg-
ioselective protection of the first glucose unit at position 3 and two
glycosylation reactions. On the other hand, the direct incorpora-
tion, by means of convenient O- and C-glycosylation reactions, of
the hydrophobic residues at the anomeric center could be made
in a straightforward way from peracetylated laminaribiose D
(n = 1, R0 = Ac) and laminaritriose D (n = 2, R0 = Ac).
Other important aspects of b-(1,3)-D-glucans include the immu-
nological and pharmacological effects of natural and synthetic
analogues of this polysaccharide.10 The synthesis of epoxyalkyl
b-(1,3)-D-glucans 2 has attracted some attention owing to their
implication in a variety of biological events including phagocytosis,
hydrogen peroxide and citokine synthesis,11 scavenging ability to-
ward superoxide anion,12 and as elicitors.13 Stick and co-workers
Even though both laminaribiose (1, n = 0) and laminaritriose
(1, n = 1) are commercially available, the requirement of multigram
quantities makes necessary to consider their preparation as per-
acetylated derivatives in multigram scale. The synthesis of lami-
naribiose and its peracetylated derivative has been reported
through a typical Koenigs–Knorr condensation of two glucose units
adequately functionalized.18 Different protection with acetyl and
benzyl groups in the two glucose moieties is also possible.19 A large
scale synthesis of laminaribiose has been optimized starting from
prepared b-(1,3)-di- and trisaccharides like
3 containing an
isofagomine unit, which showed to be potent inhibitors of a
b-(1,3)-glucan endo-hydrolase.14 The 1-O-methylumbelliferyl
b-(1,3)-D-pentaglucoside 4 has shown to be very stable toward
fungal glucosidases with respect to the natural pentasaccharide
(1, n = 3).15 Very recently, Constantino and co-workers reported
the synthesis of the b-(1,3)-glucan hexasaccharide 5 as a vaccine
candidate against Candida albicans (see Fig. 2).16
OH
OH
O
O
HO
HO
Z
O
O
R
H
HO
HO
n
A
Z = O, CH2
OAc
OAc
n = 1, 2
R' = Ac
O
AcO
O
AcO
HO
O
O
Z
H
H
R
AcO
AcO
n
C
B
n = 0
R' = protecting
group
n = 1, 2
OAc
O
R = alkyl, aryl, hetaryl
OAc
O
O
AcO
AcO
AcO
OAc
O
R'
AcO
n
D
Scheme 1. Retrosynthetic analysis.

E. Marca et al. / Carbohydrate Research 382 (2013) 9–18
OH
11
OH
OH
O
O
HO
O
HO
HO
HO
OH
O
O
HO
HO
HO
n
1
OAc
OAc
OAc
OAc
OAc
O
O
O
O
AcO
AcO
O
AcO
AcO
AcO
AcO
AcO
O
O
O
AcO
AcO
AcO
AcO
AcO
OAc
OAc
6
7
conditions
1
6
7
Actigum® CS6
Curdlan
H2SO4, Ac2O, 60ºC, 5 days
H2SO4, Ac2O, 50ºC, 5 days
3 g
9 g
0.4 g
3 g
starting material: 20 g
Scheme 2. Hydrolysis of scleroglucans.
OAc
OAc
OAc
OAc
i
O
O
O
O
AcO
O
AcO
O
AcO
AcO
O
O
(72-90%)
Ac
Ac
AcO
AcO
AcO
AcO
OAc
Br
n
n
6
7
8
9
n = 1
n = 2
n = 1 (78%)
n = 2 (72%)
R1
ii
(59-65%)
10, 11
n
a
b
c
d
e
f
1
1
1
1
2
2
PhCH2-
Ph(CH2)3-
Ph(CH2)5-
2-FurylCH2-
PhCH2-
Ph(CH2)3-
OR2
OR2
O
R2O
O
O
R2O
OR1
O
R2
R2O
R2O
n
R2 = Ac
R2 = H
iii
(97-99%)
10a-f
11a-f
Scheme 3. Synthesis of O-glycosides. Reagents and conditions: (i) 30% HBr, AcOH, rt, 15 min; (ii) R1OH, AgCO3, CH2Cl2, rt, 20 h; (iii) NaOMe, MeOH, rt, 4 h.
peracetylated donors and diacetone-
D
-glucose. The procedure al-
from the O-acetyl precursors 6 and 7, respectively (Scheme 3). Bro-
mination of peracetylated derivatives was carried out with a 30%
solution of hydrogen bromide in acetic acid, in a similar way to
that reported for peracetyl glucose.25 In the case of compounds 6
and 7, however, the reaction time, not exceeding of 15 min, was
crucial to obtain good chemical yields because of the partial hydro-
lysis of the glycosydic bond. The next glycosylation step was per-
formed under typical Koenigs–Knorr conditions; preliminary
chromatographic purification of the glycosyl bromides 8 and 9
was necessary to achieve good results. Treatment of 8 and 9 with
the corresponding alcohol in the presence of silver carbonate fur-
nished compound 10 in good yields. Complete O-deacetylation of
10 afforded a series of O-glycosides 11 in quantitative yields
(Scheme 3).
lows the preparation of up to 300 g of compound 1.20 An alterna-
tive to the glycosylation methods is the controlled hydrolysis of
scleroglucans, a method that has been widely used with other
polysaccharides such as hemicelluloses.21 The controlled hydroly-
sis of 20 g of Actigum CS6 following a slightly modified methodol-
ogy described by Driguez and co-workers22 afforded 3 g of
laminaribiose octacetate 2 and, more interestingly, 0.4 g of lami-
naritriose undecacetate 3. A more efficient hydrolysis was achieved
by using the linear scleroglucan Curdlan.23 Following the condi-
tions reported by Kuzuhara and co-workers,24 the hydrolysis of
20 g of crude material provided 9 g of compound 6 and 3 g of com-
pound 7, which were used for their further transformations into
the targeted di- and trisaccharides (see Scheme 2).
2.1. Synthesis of O-glycosides
2.2. Synthesis of C-glycosides
The laminarine analogues containing O-alkyl units were synthe-
sized from the corresponding glycosyl bromides 8 and 9, prepared
The synthesis of C-glycosides has received considerable atten-
tion during the last decade and several reviews cover a variety of

12
E. Marca et al. / Carbohydrate Research 382 (2013) 9–18
OAc
OAc
OAc
OAc
ii
i
O
O
O
AcO
O
O
AcO
O
AcO
AcO
8, 9
R1
O
O
Ac
Ac
(83-95%)
AcO
AcO
AcO
AcO
n
n
12
n = 1 (83%)
14a-d
13 n = 2 (85%)
iii
(94-96%)
14-16
n
R1
OR2
OR2
a
b
c
d
1
1
2
2
CO2Me
Ph
CO2Me
Ph
O
R2O
O
O
R2O
R1
O
R2
R2O
R2O
n
R2 = Ac
R2 = H
iv
(97-99%.)
15a-d
16a-d
Scheme 4. Synthesis of C-glycosides. Reagents and conditions: (i) AllylMgBr, Et2O, reflux, then Ac2O, Py, DMAP, rt, 12 h; (ii) Methyl acrylate or styrene, 2nd gen. Grubbs
catalyst, CH2Cl2, reflux, 3 h; (iii) H2, MeOH, Pd(OH)2-C, rt, 100 bar, 1.5 h. (iv) NaOMe, MeOH, rt, 4 h.
synthetic approaches26 including the use of exo-glycals.27 Most of
these approaches are focused on the preparation of monosaccha-
rides and with the exception of imino-C-disaccharides28 are not
very reliable for the preparation of oligosaccharide derivatives.
One of the more attractive strategies for the obtention of C-glyco-
sides derived from complex carbohydrates is the use of cross-cou-
pling reactions.29 Although these reactions are mostly dedicated to
the preparation of aryl-C-glycosides,30 Gagne and co-workers
reported31 the synthesis of alkyl-C-glycosides through a Negishi
cross-coupling using the corresponding alkylzinc derivatives and
glycosyl bromides. Unfortunately, even though we verified that
the reaction could be used with monosaccharides, when com-
pounds 8 and 9 were employed as substrates only decomposition
products were obtained.
We then turned our attention to the addition of Grignard deriv-
atives, which had also been successfully reported for the prepara-
tion of alkyl-C-glycosides.32 Again, unsuccessful results were
obtained with a series of phenyl alkylmagnesium halides and com-
pounds 8 and 9; only the addition of allylmagnesium bromide fur-
nished C-glycosides 12 and 13 in good yields (Scheme 4). In both
cases the b-anomers were obtained as the only product of the reac-
tion as expected by the presence of an acetoxy group at position 2.
Thus, we decided to elongate the anomeric chain by a metathesis
reaction following a strategy that had been successfully applied
to monosaccharides.33
Cross-metathesis of compounds 12 and 13 with methyl acrylate
and styrene in the presence of 2nd generation Grubbs catalyst
afforded compounds 14 in very good yields. Hydrogenation of 14
over Pearlman’s catalyst in MeOH gave compounds 15, which were
then treated with sodium methoxide in methanol to provide C-gly-
cosides 16 in excellent yields. For compounds 16b and 16c the pro-
cess was carried out in a one-pot procedure from allylic derivatives
12 and 13, respectively without isolating 14b,c and 15b,c thus
demonstrating that no intermediate purification is necessary. Thus,
the final C-glycosides can be obtained in two steps starting from
the corresponding glycosyl bromides 8 and 9.
Unfortunately, all the compounds have negligible inhibitory
activity toward the studied enzymes.
The oligosaccharides 11a–f and 16a,d have also been evaluated
for their inhibitory activities toward endo-b-1,3-glucanase (Barley)
and endo-b-1,3(4)-D-glucanase from Clostridum thermocellum. A
commercial kit for evaluating glucanase activity containing AZCL-
Pachyman (GlucazymeÒ from Megazyme) was used. Also in this
case a complete absence of inhibitory activity was observed.
4. Conclusions
In conclusion, a series of novel O-alkyl and C-alkyl b-(1,3)-di-
and triglucosides containing a hydrophobic moiety at the end of
the allylic chain have systematically synthesized as potential gly-
coside hydrolases inhibitors. The approach described in this paper
combines efficiency and flexibility since it allows the preparation
of a variety of di- and trisaccharides. The glycosyl bromides 8
and 9 used as starting materials are prepared in good chemical
yields from peracetylated laminaribiose and laminaritriose. The
synthesis of C-glycosides can be carried out in two steps and excel-
lent selectivity by grouping in a one-pot procedure the final
metathesis, hydrogenation, and deacetylation reactions, which
are made from common allyl derivatives 12 and 13. The biological
activity of the synthesized glycomimetics has been evaluated to-
ward 4 commercially available glycosidases and endo-glucanases.
The observed lack of activities can probably be related to the
spatial disposition of the chains located at the anomeric position.
Nevertheless, the synthetic strategy described here is facile and
general, and could be extended to increase the diversity of the
glycosidase and transglycosylase inhibitors obtained since this
diversity is introduced very efficiently. Thus, the extension of this
methodology for the preparation of other members of the same
family to be used as glycomimetics is underway.
5. Experimental part
5.1. General methods
3. Biological assays
The reaction flasks and other glass equipment were heated in an
oven at 130 °C overnight and assembled in a stream of Ar. All reac-
tions were monitored by TLC on silica gel 60 F254; the position of
the spots was detected with 254 nm UV light or by spraying with
either 5% ethanolic phosphomolybdic acid or Mostain solution.
Column chromatography was carried out in a Buchi 800 MPLC
Compounds 11a–f and 16a,d were tested on several glycoside
hydrolases to assess the effect of introducing alkyl chains with a
hydrophobic terminus at the anomeric position. Commercial
a-glucosidase from Saccharomyces cerevisae and a-galactosidase
from green coffee bean were used as enzymes and 2,4-dinitrophenyl
glucose and galactose were used, respectively, as substrates.

E. Marca et al. / Carbohydrate Research 382 (2013) 9–18
13
system or a Combiflash apparatus, using silica gel 60 microns and
with solvents distilled prior to use. Melting points were uncor-
rected. 1H and 13C NMR spectra were recorded on Bruker Avance
400 instrument in the stated solvent. Purification by semiprepara-
Cl2); 1H NMR (CDCl3, 400 MHz): d 1.97 (s, 3H, Me), 1.99 (s, 3H,
Me), 2.01 (s, 3H, Me), 2.01 (s, 3H, Me), 2.04 (s, 3H, Me), 2.04 (s,
3H, Me), 2.06 (s, 3H, Me), 2.07 (s, 3H, Me), 2.08 (s, 3H, Me), 2.21
(s, 3H, Me), 3.66–3.73 (m, 2H, H11, H17), 3.82 (t, 1H, J = 9.4 Hz,
H9), 4.00–4.32 (m, 6H, H3, H5, H6, H12a, H18a), 4.32 (dd, 1H, J = 4.5,
12.5 Hz, H12b), 4.37 (dd, 1H, J = 4.1, 12.4 Hz, H18b), 4.53 (d, 1H,
J = 8.06 Hz, H13), 4.56 (d, 1H, J = 8.1 Hz, H7), 4.77 (dd, 1H, J = 4.0,
9.7 Hz, H2), 4.86–4.95 (m, 3H, H8, H10, H14), 5.02–5.14 (m, 3H, H4,
tive HPLC (column AtlantisÒ DC18 5
lm, 19 ꢀ 100 mm, flow:
12.5 mL/min) was carried out in a Waters 515 pump with PDA
and ELSD detection. Chemical shifts are reported in ppm (d) rela-
tive to CHCl3 (d = 7.26) in CDCl3. Optical rotations were taken on
a JASCO DIP-370 polarimeter. Elemental analyses were performed
on a Perkin Elmer 240B microanalyzer or with a Perkin-Elmer 2400
instrument. Laminaribiose octaacetate 6 and laminaritriose undec-
aacetate 7 were prepared as described.22 The numbering scheme in
NMR assignments for the prepared compounds follows the follow-
ing scheme illustrated for compound 10f:
H
15, H16), 6.51 (d, 1H, J = 4.0 Hz, H1); 13C NMR (CDCl3, 100 MHz):
d 20.4 (2C, Me), 20.5 (Me), 20.6 (Me), 20.7 (Me), 20.7 (Me), 20.9
(Me), 61.1 (C18), 61.7 (C12), 61.8 (C6), 66.5 (C4), 68.0 (2C, C14, C16),
70.9 (C8), 71.6 (C11), 71.6 (C17), 72.4 (C5), 72.5 (C2), 72.7 (C10),
72.8 (C15), 76.1 (C3), 78.0 (C9), 87.4 (C1), 100.7 (C7), 101.0 (C13),
168.4 (C@O), 168.9 (C@O), 169.1 (C@O), 169.2 (C@O), 169.4
(C@O), 170.3 (C@O), 170.5 (C@O), 170.6 (C@O). Anal. Calcd for
C38 H51BrO25: C, 46.21; H, 5.20; Br, 8.09. Found: C, 46.35; H, 5.05;
Br, 8.14.
Me
OAc
Me
18
Me
AcO
15
OAc
16
17
O
Me
12
Me AcO
OAc
14
5.3. General procedure for the glycosylation of glycosyl
bromides
13
O
Me
OAc
10
9
8
11
O
7
Me
AcO
OAc
Me
6
A solution of the corresponding glycosyl bromide (1 mmol) and
alcohol (1 mmol) in anhydrous dichloromethane (8 mL) was trea-
ted in the darkness and under an argon atmosphere with silver car-
bonate (1.18 mmol) and a catalytic amount (a small crystal) of
iodine. The resulting solution was stirred at ambient temperature
for 20 h and diluted with dichloromethane (10 mL). The reaction
mixture was filtered through a pad of CeliteÒ and the filtrate was
evaporated under reduced pressure to give the crude product
which was purified by column chromatography.
O
OAc
4
Me
3
5
O
10f
AcO
2
1
20
Me
O
Ph
19
21
5.2. General procedure for the synthesis of glycosyl bromides
solution of the corresponding peracetylated laminarin
A
5.3.1. Benzyl 2,3,4,6-tetra-O-acetyl-b-D-glucopyranosyl-(1?3)-
derivative (6 or 7, 1 mmol) in 30% hydrogen bromide in acetic
acid (10 mL) was stirred at ambient temperature for 15 min at
which time the reaction mixture was poured into 50 mL of ice-
water. The resulting white solid was extracted with dichloro-
methane (3 ꢀ 30 mL). The combined organic extracts were dried
over magnesium sulfate and the solvent was eliminated under
reduced pressure to give the crude product which was purified
by column chromatography.
2,4,6-tri-O-acetyl- -glucopyranoside (10a)
a
-D
Following the general procedure, the reaction of 8 (0.700 g,
1 mmol) and benzyl alcohol (0.108 g, 1 mmol) afforded 10a
(0.356 g, 62%) as a white solid. Mp 169–171 °C; Rf = 0.42 (hexane/
EtOAc, 2:3); ½a 2D5
ꢁ
ꢂ44 (c 1.00, CHCl3); 1H NMR (CDCl3, 400 MHz):
d 1.97 (s, 3H, Me), 2.00 (s, 3H, Me), 2.01 (s, 3H, Me), 2.01 (s, 3H,
Me), 2.06 (s, 3H, Me), 2.08 (s, 3H, Me), 2.10 (s, 3H, Me), 3.61–3.66
(m, 2H, H5, H11), 3.84 (t, 1H, J = 9.5 Hz, H3), 4.01 (dd, 1H, J = 2.3,
12.4 Hz, H12a), 4.19–4.21 (m, 2H, H6), 4.34 (dd, 1H, J = 4.3,
12.4 Hz, H12b), 4.39 (d, 1H, J = 8.1 Hz, H1), 4.55–4.60 (m, 2H, H7,
H13), 4.86–4.91 (m, 2H, H8, H13), 4.97 (t, 1H, J = 9.7 Hz, H4), 5.02–
5.08 (m, 2H, H2, H10), 5.11 (t, 1H, J = 9.4 Hz, H9), 7.24–7.29 (m,
2H, ArH), 7.29–7.37 (m, 3H, ArH); 13C NMR (CDCl3, 100 MHz): d
20.3 (Me), 20.5 (2C, Me), 20.6 (Me), 20.8 (Me), 20.9 (Me), 61.7
(C12), 62.1 (C6), 68.0 (C10), 68.2 (C4), 70.2 (CH2Ph), 71.0 (C8), 71.6
(C5), 71.8 (C11), 72.7 (C2), 72.9 (C9), 78.9 (C3), 99.0 (C1), 100.9
(C1), 127.7 (Ar), 127.9 (Ar), 128.4 (Ar), 136.8 (Ar), 168.8 (C@O),
169.1 (C@O), 169.2 (C@O), 169.4 (C@O), 170.3 (C@O), 170.5
(C@O), 170.7 (C@O). Anal. Calcd for C33H42O18: C, 54.54; H, 5.83.
Found: C, 54.65; H, 5.71.
5.2.1. 2,3,4,6-Tetra-O-acetyl-b-
D-glucopyranosyl-(1?3)-1-
bromo-2,4,6-tri-O-acetyl- -glucopyranose (8)
a
-D
Following the general procedure, the reaction of 6 (0.679 g,
1 mmol) afforded 8 (0.562 g, 81%) as a sticky foam; Rf = 0.23 (hex-
ane/EtOAc, 3:2); +39 (c 1.10, CH2Cl2); 1H NMR (CDCl3, 400 MHz): d
1.96 (s, 3H, Me), 1.98 (s, 3H, Me), 2.01 (s, 3H, Me), 2.05 (s, 3H, Me),
2.08 (s, 3H, Me), 2.09 (s, 3H, Me), 2.19 (s, 3H, Me), 3.74 (ddd, 1H,
J = 2.3, 4.2, 9.8 Hz, H11), 4.28-4.04 (m, 5H, H3, H5, H6, H12a), 4.38
(dd, 1H, J = 4.3, 12.5 Hz, H12b), 4.68 (d, 1H, J = 8.1 Hz, H7), 4.81
(dd, 1H, J = 4.0, 9.7 Hz, H2), 4.90 (dd, 1H, J = 8.2, 9.4 Hz, H8), 5.03–
5.19 (m, 3H, H4, H9, H10), 6.51 (d, 1H, J = 4.03 Hz, H1); 13C NMR
(CDCl3, 100 MHz): d 20.3 (Me), 20,4 (Me), 20.5 (2C, Me), 20.6
(Me), 20.7 (Me), 20.8 (Me), 61.1 (C6), 61.6 (C12), 66.5 (C4), 67.9
(C9), 71.4 (C8), 71.7 (C11), 72.3 (C2), 72.24 (C5), 72.9 (C10), 76.4
(C3), 87.3 (C1), 100.7 (C7), 169.0 (2C, C@O), 169.3 (C@O), 169.5
(C@O), 170.3 (C@O), 170.5 (C@O), 170.6 (C@O). Anal. Calcd for
C26 H35BrO17: C, 44.65; H, 5.04; Br, 11.42. Found: C, 44.38; H,
5.11; Br, 11.56.
5.3.2. 3-Phenylpropyl 2,3,4,6-tetra-O-acetyl-b-D-glucopyranosyl-
(1?3)-2,4,6-tri-O-acetyl- -glucopyranoside (10b)
a-D
Following the general procedure, the reaction of 8 (0.700 g,
1 mmol) and 3-phenylpropan-1-ol (0.137 g, 1 mmol) afforded
10b (0.456 g, 65%) as a yellow oil; Rf = 0.50 (hexane/EtOAc, 3:7);
½
a 2D5
ꢁ
ꢂ32 (c 1.11 CHCl3); 1H NMR (CDCl3, 400 MHz): d 1.80–1.95
(m, 2H, H14), 1.98 (s, 3H, Me), 2.01 (s, 3H, Me), 2.02 (s, 3H, Me),
2.03 (s, 3H, Me), 2.04 (s, 6H, Me), 2.08 (s, 3H, Me), 2.14 (s, 3H,
Me), 2.58–2.73 (m, 2H, H15), 3.43 (ddd, 1H, J = 5.8, 7.4, 9.6 Hz,
5.2.2. 2,3,4,6-Tetra-O-acetyl-b-D-glucopyranosyl-(1?3)-2,4,6-tri-
O-acetyl-b- -glucopyranosyl-(1?3)-1-bromo-2,4,6-tri-O-acetyl-
D
b-
D-glucopyranose (9)
H13a), 3.63–3.71 (m, 2H, H5, H11), 3.84–3.90 (m, 2H, H3, H13b),
Following the general procedure, the reaction of 7 (0.967 g,
4.05 (dd, 1H, J = 4.7, 12.4 Hz, H12a), 4.13–4.18 (m, 1H, H6a), 4.20
(dd, 1H, J = 4.7, 12.4 Hz, H6b), 4.36–4.39 (m, 2H, H1, H12b), 4.61
(d, 1H, J = 8.1 Hz, H7), 4.90 (dd, 1H, J = 8.2, 9.5 Hz, H8), 4.96 (t, 1H,
1 mmol) afforded
9
(0.467 g, 76%) as
a
ꢁ
white solid. mp
+33 (c 1.00, CH2-
116–118 °C; Rf = 0.56 (hexane/EtOAc, 7:3); ½a D25

14
E. Marca et al. / Carbohydrate Research 382 (2013) 9–18
J = 9.6 Hz, H4), 5.03 (dd, 1H, J = 8.1, 9.7 Hz, H2), 5.07 (t, 1H,
J = 9.7 Hz, H10), 5.14 (t, 1H, J = 9.5 Hz, H9), 7.15–7.21 (m, 3H, ArH),
7.26–7.30 (m, 2H, ArH); 13C NMR (CDCl3, 100 MHz): d 20.3 (Me),
20.4 (Me), 20.5 (Me), 20.6 (Me), 20.7 (Me), 20.8 (Me), 21.0 (Me),
31.1 (C14), 31.8 (C15), 61.6 (C12), 62.2 (C6), 68.0 (C10), 68.4 (C4),
68.7 (C13), 71.1 (C8), 71.6 (C11), 71.8 (C5)5, 72.8 (C2), 79.0 (C9),
100.8 (C1), 101.1 (C7), 125.8 (Ar), 128.3 (Ar), 128.4 (Ar), 142.0
(Ar), 168.7 (C@O), 169.1 (C@O), 169.2 (C@O), 169.2 (C@O), 169.2
(C@O), 169.2 (C@O), 169.4 (C@O), 170.3 (C@O), 170.5 (C@O),
170.6 (C@O), 170.8 (C@O). Anal. Calcd for C35H46O18: C, 55.70; H,
6.14. Found: C, 55.59; H, 6.30.
EtOAc, 3:7); 1H NMR (CDCl3, 400 MHz): d 1.96 (s, 3H, Me), 1.99
(s, 3H, Me), 2.00 (s, 3H, Me), 2.01 (s, 3H, Me), 2.02(s, 3H, Me),
2.05(s, 3H, Me), 2.06(s, 3H, Me), 2.09 (s, 3H, Me), 2.10 (s, 3H, Me),
3.59–5.68 (m, 3H, H5, H11, H17), 3.78 (t, 1H, J = 9.4 Hz, H9), 3.83 (t,
1H, J = 9.3 Hz, H3), 4.02 (d, 2H, J = 12.0 Hz, H12a, H18a), 4.18 (d, 2H,
J = 3.6 Hz, H6), 4.28 (dd, 1H, J = 4.5, 12.4 Hz, H12b), 4.35–4.45 (m,
3H, H1, H7, H18b), 4.49 (d, 1H, J = 8.1 Hz, H13), 4.57 (d, 1H, J = 12.4
H, H19a), 4.84–4.95 (m, 5H, H4, H8, H10, H14, H19b), 5.00–5.13 (m,
3H, H2, H15, H16), 7.25–7.37 (m, 5H, ArH); 13C NMR (CDCl3,
100 MHz): d 20.3 (Me), 20.4 (Me), 20.5 (2C, Me), 20.6 (Me), 20.7
(2C, Me), 20.8 (Me), 21.0 (Me), 61.6 (C18), 61.9 (C12), 62.2 (C6),
68.0 (C16), 68.3 (C8), 68.5 (C4), 70.2 (C19), 70.8 (C14), 71.5 (C17),
71.6 (C5), 71.8 (C11), 72.6 (C10), 72.8 (C15), 72.9 (C2), 78.2 (C3),
78.9 (C9), 99.0 (C1), 100.6 (C7), 101.0 (C13), 127.7 (Ar), 127.9 (Ar),
128.4 (Ar), 136.8 (Ar), 168.8 (C=O), 169.1 (2C, C@O), 169.2 (C@O),
169.4 (C@O), 170.3 (C@O), 170.5 (C@O), 170.6 (C@O), 170 (C@O).
Anal. Calcd for C45H58O26: C, 53.25; H, 5.76. Found: C, 53.07; H,
5.52.
5.3.3. 5-Phenylpentyl 2,3,4,6-tetra-O-acetyl-b-D-glucopyranosyl-
(1?3)-2,4,6-tri-O-acetyl- -glucopyranoside (10c)
a-D
Following the general procedure, the reaction of 8 (0.700 g,
1 mmol) and 3-phenylpentan-1-ol (0.164 g, 1 mmol) afforded 10c
(0.209 g, 61%) as a yellow oil; Rf = 0.48 (hexane/EtOAc, 2:3); ½a D25
ꢁ
ꢂ29 (c 1.00 CH2Cl2); 1H NMR (CDCl3, 400 MHz): d 1.35–1.40 (m,
2H, H15), 1.51–1.65 (m, 4H, H14, H16), 1.97 (s, 3H, Me), 2.00 (s,
3H, Me), 2.01 (s, 3H, Me), 2.02 (s, 3H, Me), 2.04 (s, 3H, Me), 2.06
(s, 3H, Me), 2.07 (s, 3H, Me), 2.08 (s, 3H, Me), 2.57–2.61 (m, 2H,
5.3.6. 3-Phenylpropyl 2,3,4,6-tetra-O-acetyl-b-
(1?3)-2,4,6-tri-O-acetyl-b- -glucopyranosyl-(1?3)-2,4,6-tri-O-
acetyl-b- -glucopyranoside (10f)
D-glucopyranosyl-
D
H17), 3.41 (td, 1H, J = 6.8,.5 Hz, H13a), 3.62–3.69 (m, 2H, H5, H11),
D
3.81–3.88 (m, 2H, H3, H13b), 4.04 (dd, 1H, J = 2.3, 12.4 Hz, H12a),
4.13–4.21 (m, 2H, H6), 4.33 (d, 1H, J = 8.1 Hz, H1), 4.36 (dd, 1H,
J = 4.3, J = 12.4 Hz, H12b), 4.58 (d, 1H, J = 8.1 Hz, H7), 4.86–4.99 (m,
3H, H2, H4, H8), 5.06 (t, 1H, J = 9.6 Hz, H10), 5.13 (t, 1H, J = 9.4 Hz,
H9), 7.15–7.19 (m, 3H, ArH), 7.25–7.29 (m, 2H, ArH); 13C NMR
(CDCl3, 100 MHz): d 20.2 (Me), 20.3 (Me), 20.4 (Me), 20.4 (Me),
20.5 (Me), 20.6 (Me), 20.7 (Me), 25.3 (C15), 29.1 (C14), 30.9 (C16),
35.7 (C17), 61.5 (C12), 62.0 (C6), 67.9 (C10), 68.1 (C4), 69.5 (C13),
70.9 (C8), 71.5 (C11), 71.6 (C5), 72.5 (C2), 72.8 (C9), 78.8 (C3),
100.6 (C1), 100.7 (C7), 125.5 (Ar), 128.1 (Ar), 128.2 (Ar), 142.3
(Ar), 168.6 (C@O), 169.1 (C@O), 169.1 (C@O), 169.2 (C@O), 170.2
(C@O), 170.3 (C@O), 170.6 (C@O). Anal. Calcd for C37H50O18: C,
56.77; H, 6.44. Found: C, 56.64; H, 6.31.
Following the general procedure, the reaction of 9 (0.987 g,
1 mmol) and 3-phenylpropan-1-ol (0.137 g, 1 mmol) afforded 10f
(0.218 g, 63%); white solid. Mp 95–97 °C; Rf = 0.29 (hexane/EtOAc,
3:7); ½a 2D5
ꢁ
ꢂ43 (c 1, CHCl3); 1H NMR (CDCl3, 400 MHz): d 1.79–1.94
(m, 2H, H20), 1.97 (s, 3H, Me), 1.99 (s, 3H, Me), 2.00 (s, 3H, Me), 2.01
(s, 3H, Me), 2.02 (s, 3H, Me), 2.04 (s, 3H, Me), 2.05 (s, 3H, Me), 2.06
(s, 3H, Me), 2.07 (s, 3H, Me), 2.10 (s, 3H, Me), 2.15 (s, 3H, Me), 2.57–
2.70 (m, 2H, H21), 3.39–3.44 (m, 1H, H19a), 3.64–3.69 (m, 3H, H5,
H11, H17), 3.80 (t, 1H, J = 9.3 Hz, H9), 3.83–3.89 (m, 2H, H3, H19b),
4.01–4.06 (m, 2H, H12a, H18a), 4.13–4.19 (m, 2H, H6), 4.31 (dd,
1H, J = 4.4, 12.4 Hz, H12b), 4.35 (d, 1H, J = 8.0 Hz, H1), 4.38 (dd,
1H, J = 3.9, 12.5 Hz, H18b), 4.46 (d, 1H, J = 8.1 Hz, H7), 4.50 (d, 1H,
J = 8.1 Hz, H13), 4.85–4.93 (m, 4H, H4, H8, H10, H14), 4.99 (dd, 1H,
J = 8.2, 9.3 Hz, H2), 5.05 (t, 1H, J = 9.6 Hz, H16), 5.11 (t, 1H,
J = 9.4 Hz, H15), 7.17–7.20 (m, 3H, ArH), 7.26–7.30 (m, 2H, ArH);
13C NMR (CDCl3, 100 MHz): d 20.3 (Me), 20.4 (Me), 20.5 (2C, Me),
20.6 (Me), 20.7 (Me), 20.8 (Me), 21.0 (Me), 31.1 (C20), 31.8 (C21),
61.6 (C18), 62.0 (C12), 62.2 (C6), 68.0 (C16), 68.4 (C4), 68.6 (C19),
70.8 (C14), 71.6 (2C, C5 or C11 or C17), 71.7 (C5 or C11 or C17), 72.6
(C10), 72.8 (C15), 73.1 (C2), 78.2 (C3), 78.9 (C9), 100.7 (2C, C1, C7),
101.0 (C13), 125.9 (Ar), 128.3 (Ar), 128.4 (Ar), 141.5 (Ar), 168.8
(2C, C@O), 169.1 (C@O), 169.2 (C@O), 169.3 (C@O), 169.5 (C@O),
170.3 (C@O), 170.5 (C@O), 170.6 (C@O), 170.8 (C@O). Anal. Calcd
for C47H62O26: C, 54.13; H, 5.99. Found: C, 54.34; H, 6.17.
5.3.4. Furylmethyl 2,3,4,6-tetra-O-acetyl-b-D-glucopyranosyl-
(1?3)-2,4,6-tri-O-acetyl- -glucopyranoside (10d)
a-D
Following the general procedure, the reaction of 8 (0.700 g,
1 mmol) and furfuryl alcohol (0.098 g, 1 mmol) afforded 10d
(0.332 g, 59%) as a white solid; mp 148–150 °C; Rf = 0.52 (hex-
ane/EtOAc, 2:3); ½a D25
ꢁ
ꢂ47 (c 1.02, CH2Cl2); 1H NMR (CDCl3,
400 MHz): d 1.97 (s, 3H, Me), 1.99 (s, 3H, Me), 2.00 (s, 3H, Me),
2.02 (s, 3H, Me), 2.04 (s, 3H, Me), 2.07 (s, 3H, Me), 2.09 (s, 3H,
Me), 3.62–3.69 (m, 2H, H5, H11), 3.85 (t, 1H, J = 9.4 Hz, H3), 4.02
(dd, 1H, J = 2.3, 12.4 Hz, H12a), 4.15–4.22 (m, 2H, H6), 4.35 (dd,
1H, J = 4.3, 12.4 Hz, H12b), 4.42 (d, 1H, J = 8.1 Hz, H1), 4.56 (d, 1H,
J = 8.1 Hz, H7), 4.59 (d, 1H, J = 13.3 Hz, H13a), 4.72 (d, 1H,
J = 13.3 Hz, H13b), 4.87 (dd, 1H, J = 8.2, 9.3 Hz, H8), 4.95 (t, 1H,
J = 9.6 Hz, H4), 4.99 (dd, 1H, J = 13.3 Hz, H2), 5.04 (t, 1H, J = 9.6 Hz,
5.4. General procedure for the allylation of glycosyl bromides
A solution of the glycosyl bromide (0.266 g, 0.38 mmol of 8
and 0.27 mmol of 9) was treated dropwise with a solution of
allylmagnesium bromide (6 mL of a 1 M solution in diethy ether,
6 mmol) under an argon atmosphere and the resulting solution
was stirred at reflux for 5 h. The reaction mixture was then
poured into ice-water (20 mL). The aqueous layer was separated,
washed with ethyl acetate (2 ꢀ 10 mL), and lyophilized. The
resulting solid was taken up in pyridine (25 mL) and treated with
acetic anhydride (25 mL) and a catalytic amount of N,N-dimethyl-
aminopyridine (DMAP). The reaction mixture was stirred for addi-
tional 12 h at which time was diluted with water (40 mL) and
extracted with diethyl ether (3 ꢀ 40 mL). The combined organic
extracts were washed sequentially with 1 N sodium hydroxide
(1 ꢀ 25 mL), saturated aqueous sodium bicarbonate (1 ꢀ 25 mL),
saturated aqueous copper sulfate (2 ꢀ 25 mL), and brine
(1 ꢀ 25 mL). The organic layer was separated, dried over
magnesium sulfate, filtered, and evaporated under reduced pres-
H10), 5.11 (t, 1H, J = 9.4 Hz, H9), 6.32 (d, 1H, J = 3.1 Hz, H15), 6.35
(d, 1H, J = 1.9, 3.2 Hz, H14), 7.41 (dd, 1H, J = 0.8, 1.8 Hz, H16); 13C
NMR (CDCl3, 100 MHz): d 20.2 (Me), 20.3 (Me), 20.4 (Me), 20.5
(Me), 20.6 (Me), 61.5 (C12), 62.0 (C6), 62.1 (C13), 67.9 (C10), 68.1
(C4), 70.9 (C8), 71.5 (C5 or C11), 71.7 (C5 or C11), 72.4 (C2), 72.8
(C9), 78.8 (C3), 98.6 (C1), 100.7 (C7), 110.1 (Ar), 110.3 (Ar), 143.0
(Ar), 150.3 (Ar), 168.8 (C@O), 169.1 (C@O), 169.2 (C@O), 169.3
(C@O), 170.2 (C@O), 170.3 (C@O), 170.6 (C@O). Anal. Calcd for
C31H40O19: C, 51.96; H, 5.63. Found: C, 52.11; H, 5.48.
5.3.5. Benzyl 2,3,4,6-tetra-O-acetyl-b-
2,4,6-tri-O-acetyl-b- -glucopyranosyl-(1?3)-2,4,6-tri-O-acetyl-
b- -glucopyranoside (10e)
Following the general procedure, the reaction of 9 (0.987 g,
D-glucopyranosyl-(1?3)-
D
D
1 mmol) and 3-phenylpropan-1-ol (0.137 g, 1 mmol) afforded 10e
(0.198 g, 65%) as a white solid. Mp 100–102 °C; Rf = 0.34 (hexane/

E. Marca et al. / Carbohydrate Research 382 (2013) 9–18
15
sure to give the crude product which was purified by column
chromatography.
5.5.1. 2,3,4,6-Tetra-O-acetyl-b-
deoxy-1-((E)-4-methoxy-4-oxobut-2-en-1-yl)-2,4,6-tri-O-acetyl-
D-glucopyranosyl-(1?3)-1-
b-D
-glucopyranose (14a)
5.4.1. 2,3,4,6-Tetra-O-acetyl-b-
D-glucopyranosyl-(1?3)-1-allyl-
Following the general procedure, the reaction of 12 (0.661 g,
1-deoxy-2,4,6-tri-O-acetyl-b- -glucopyranose (12)
D
1 mmol) with methyl acrylate (1.21 g, 14 mmol) afforded 14a
(0.195 g, 90%) as a white soild; mp 84–86 °C; Rf = 0.46 (hexane/
Following the general procedure, the reaction of 8 (0.266 g,
0.38 mmol) with allylmagnesium bromide (6 mL of a 1 M solu-
tion in diethy ether, 6 mmol) afforded 12 (0.398 g, 83%) as a
EtOAc, 7:3);
½
a 2D5
ꢁ
ꢂ13 (c 1.00, CHCl3); 1H NMR (CDCl3,
400 MHz): d 1.97 (s, 3H, Me), 2.00 (s, 3H, Me), 2.01 (s, 3H,
Me), 2.03 (s, 3H, Me), 2.04 (s, 3H, Me) 2.07 (s, 3H, Me), 2.07 (s,
3H, Me), 2.32–2.43 (m, 2H, H13), 3.38–3.43 (m, 1H, H1), 3.60
(ddd, 1H, J = 2.3, 5.2, 10.1 Hz, H5), 3.68 (ddd, 1H, J = 2.4, 4.1,
9.7 Hz, H11), 3.72 (s, 3H, OMe), 3.84 (t, 1H, J = 9.3 Hz, H3), 4.04
(dd, 1H, J = 2.3, 12.4 Hz, H12a), 4.08–4.13 (m, 1H, H6a), 4.16 (dd,
1H, J = 5.3, 12.3 Hz, H6b), 4.38 (dd, 1H, J = 4.3, 12.4 Hz, H12b),
4.57 (d, 1H, J = 8.1 Hz, H7), 4.88–4.95 (m, 3H, H2, H4, H8), 5.06
(t, 1H, J = 9.6 Hz, H10), 5.11 (t, 1H, J = 9.4 Hz, H9), 5.87 (td, 1H,
J = 1.3, 15.7 Hz, H15), 6.90 (td, 1H, J = 6.9, 15.7 Hz, H14); 13C
NMR (CDCl3, 100 MHz): d 20.3 (Me), 20.4 (Me), 20.5 (Me), 20.6
(Me), 20.7 (Me), 21.0 (Me), 34.1 (C13), 51.5 (OMe), 61.6 (C12),
62.4 (C6), 67.9 (C10), 68.2 (C4), 71.0 (C8), 71.7 (C11), 73.0 (C9),
73.6 (C2), 75.8 (C5), 76.4 (C1), 80.2 (C3), 101.0 (C7), 123.4 (C15),
143.4 (C14), 166.6 (C@O), 169.2 (C@O), 169.4 (C@O), 170.4
(C@O), 170.5 (C@O), 170.7 (C@O). Anal. Calcd for C31H42O19: C,
51.81; H, 5.89. Found: C, 51.75; H, 5.97.
white solid. Mp 148–150 °C; Rf = 0.19 (hexane/EtOAc, 7:3); ½a D25
ꢁ
ꢂ22 (c 1.03, CHCl3); 1H NMR (CDCl3, 400 MHz): d 1.97 (s, 3H,
Me), 2.00 (s, 3H, Me), 2.02 (s, 3H, Me), 2.02 (s, 3H, Me), 2.06
(s, 3H, Me), 2.07 (s, 3H, Me), 2.12 (s, 3H, Me), 2.21–2.25 (m,
2H, H13), 3.34 (ddd, 1H, J = 5.1, 6.7, 9.9 Hz, H1), 3.58 (ddd, 1H,
J = 2.3, 4.9, 10.0 Hz, H5), 3.67 (ddd, 1H, J = 2.4, 4.2, 9.7 Hz, H11),
3.82 (t, 1H, J = 9.4 Hz, H3), 4.04 (dd, 1H, J = 2.3, 12.4 Hz, H12a),
4.09–4.14 (m, 1H, H6a), 4.16 (dd, 1H, J = 5.0, 12.2 Hz, H6b), 4.38
(dd, 1H, J = 4.3, 12.4 Hz, H12b), 4.57 (d, 1H, J = 7.0 Hz, H7), 4.88–
4.94 (m, 3H, H2, H4, H8), 5.03–5.13 (m, 4H, H9, H10, H15, H15),
5.74–5.84 (m, 1H, H14); 13C NMR (CDCl3, 100 MHz): d 20.3
(Me), 20.5 (Me), 20.5 (Me), 20.5 (Me), 20.6 (Me), 20.8 (Me),
21.1 (Me), 35.7 (C13), 61.7 (C12), 62.5 (C6), 68.0 (C10), 68.4 (C4),
71.0 (C8), 71.7 (C11), 73.0 (C9), 73.6 (C2), 75.7 (C5), 77.4 (C1),
80.4 (C3), 101.0 (C7), 117.3 (C14), 133.2 (C15), 169.3 (C@O),
169.3 (C@O), 169.3 (C@O), 170.4 (C@O), 170.5 (C@O), 170.8
(C@O). Anal. Calcd for C29H40O17: C, 52.73; H, 6.10. Found: C,
52.873; H, 6.01.
5.5.2. 2,3,4,6-Tetra-O-acetyl-b-
O-acetyl-b- -glucopyranosyl-(1?3)-1-((E)-3-phenylprop-2-en-
1-yl)-1-deoxy-2,4,6-tri-O-acetyl-b- -glucopyranose (14d)
D-glucopyranosyl-(1?3)-2,4,6-tri-
D
D
5.4.2. 2,3,4,6-Tetra-O-acetyl-b-
O-acetyl-b- -glucopyranosyl-(1?3)-1-allyl-1-deoxy-2,4,6-tri-O-
acetyl-b- -glucopyranose (13)
D-glucopyranosyl-(1?3)-2,4,6-tri-
Following the general procedure, the reaction of 13 (0.949 g,
1 mmol) with styrene (1.46 g, 14 mmol) afforded 14d (0.221 g,
D
D
92%) as an oil; Rf = 0.26 (hexane/EtOAc, 2:3); ½a D25
ꢂ34 (c 0.5,
ꢁ
Following the general procedure, the reaction of 9 (0.266 g,
0.27 mmol) with allylmagnesium bromide (6 mL of a 1 M solu-
tion in diethy ether, 6 mmol) afforded 13 (0.489 g, 83%) as a
CH2Cl2); 1H NMR (CDCl3, 400 MHz): d 1.97 (s, 3H, Me), 1.99 (s,
3H, Me), 2.01 (s, 3H, Me), 2.02 (s, 3H, Me), 2.02 (s, 3H,
Me),2.03 (s, 3H, Me), 2.06 (s, 3H, Me), 2.07 (s, 3H, Me), 2.10 (s,
3H, Me), 2.11 (s, 3H, Me), 2.33–2.45 (m, 2H, H19), 3.40 (ddd,
1H, J = 4.8, 7.0, 9.8 Hz, H1), 3.61 (ddd, 1H, J = 2.3, 4.9, 10.0 Hz,
H5), 3.65–3.69 (m, 2H, H11, H17), 3.78 (t, 1H, J = 9.3 Hz, H9),
3.83 (t, 1H, J = 9.3 Hz, H3), 4.01–4.08 (m, 2H, H12a, H18a), 4.08–
4.13 (m, 1H, H6a), 4.16 (dd, 1H, J = 5.1, 12.3 Hz, H6b), 4.33 (dd,
1H, J = 4.4, 12.4 Hz, H12b), 4.40 (dd, 1H, J = 3.8, 12.4 Hz, H18b),
4.44 (d, 1H, J = 8.1 Hz, H7), 4.50 (d, 1H, J = 8.1 Hz, H13), 4.86–
4.96 (m, 5H, H2, H4, H8, H10, H14), 5.06 (t, 1H, J = 9.6 Hz, H16),
5.11 (t, 1H, J = 9.4 Hz, H15), 6.19 (ddd, 1H, J = 6.2, 7.8, 15.8 Hz,
white solid. Mp 88–90 °C; Rf = 0.45 (hexane/EtOAc, 3:7); ½a D25
ꢁ
ꢂ38 (c 1.01, CH2Cl2); 1H NMR (CDCl3, 400 MHz): d 1.97 (s, 3H,
Me), 1.99 (s, 3H, Me), 2.00 (s, 3H, Me), 2.01 (s, 3H, Me), 2.02
(s, 3H, Me), 2.04 (s, 3H, Me), 2.06 (s, 3H, Me), 2.10 (s, 3H, Me),
2.13 (s, 3H, Me), 2.19–2.24 (m, 2H, H19), 3.33 (td, 1H, J = 5.8,
9.9 Hz, H1), 3.58 (ddd, 1H, J = 2.6, 4.7, 9.9 Hz, H5), 3.63–3.69
(m, 2H, H11, H17), 3.75–3.83 (m, 2H, H3, H9), 4.00–4.06 (m, 2H,
H
H
12a, H18a), 4.08–4.16 (m, 2H, H6), 4.32 (dd, 1H, J = 4.5, 12.4 Hz,
12b), 4.39 (dd, 1H, J = 3.9, 12.4 Hz, H18b), 4.42 (d, 1H,
J = 8.1 Hz, H7), 4.49 (d, 1H, J = 8.1 Hz, H13), 4.86–4.93 (m, 5H,
H2, H4, H8, H10, H14), 5.03–5.13(m, 4H, H15, H16, H21), 5.78 (tdd,
1H, J = 6.7, 9.7, 16.3 Hz, H20); 13C NMR (CDCl3, 100 MHz): d
20.3 (Me), 20.4 (Me), 20.5 (Me), 20.6 (Me), 20.7 (Me), 20.7
(Me), 20.8 (Me), 21.2 (Me), 35.8 (C19), 61.6 (C18), 61.9 (C12),
62.5 (C6), 68.0 (C16), 68.2 (C10), 68.5 (C4), 70.8 (C2), 71.6 (2C,
H20), 6.39 (d, 1H, J = 15.9 Hz, H21), 7.18–7.24 (m, 1H, ArH),
7.28–7.32 (m, 2H, ArH), 7.31–7.34 (m, 2H, ArH); 13C NMR (CDCl3,
100 MHz): d 20.2 (Me), 20.3 (Me), 20.4 (Me), 20.5 (Me), 20.6
(Me), 20.6 (Me), 20.7 (Me), 21.0 (Me), 35.2 (C19), 61.5 (C18),
61.9 (C12), 62.4 (C6), 67.9 (C16), 68.1 (C10), 68.4 (C4), 70.7 (C14),
71.5 (C11 or C17), 71.5 (C11 or C17), 72.5 (C8), 72.7 (C15), 73.8
(C2), 75.6 (C5), 77.4 (C1), 79.0 (C3), 79.7 (C9), 100.7 (C7), 100.9
(C13), 124.8 (C20), 125.9 (Ar), 127.2 (Ar), 128.4 (Ar), 132.3 (C21),
137.1 (Ar), 168.6 (C@O), 169.0 (C@O), 169.1 (C@O), 169.2
(C@O), 169.3 (C@O), 170.2 (C@O), 170.4 (C@O), 170.4 (C@O),
170.7 (C@O). Anal. Calcd for C47H60O25: C, 55.08; H, 5.90. Found:
C, 54.93; H, 6.16.
C11, C17), 72.6 (C8), 72.8 (C15), 73.7 (C14), 75.7 (C5), 77.3 (C1),
79.1 (C9), 79.8 (C3), 100.8 (C7), 101.1 (C13), 117.3 (C20), 133.2
(C21), 168.7 (C@O), 169.1 (C@O), 169.2 (C@O), 169.2 (C@O),
169.4 (C@O), 170.3 (C@O), 170.5 (C@O), 170.6 (C@O), 170.8
(C@O). Anal. Calcd for C41H56O25: C, 51.90; H, 5.95. Found: C,
51.72; H, 6.17.
5.6. General procedure for the hydrogenation
5.5. General procedure for the metathesis reaction
A solution of alkene (1 mmol) in methanol (6 mL) was trea-
ted with Pearlman’s catalyst (15 mol %) and the resulting mix-
ture was stirred under hydrogen (100 bar) at ambient
temperature for 2 h. The reaction mixture was filtered through
a pad of Celite and the filtrate evaporated under reduced pres-
sure. The resulting crude product was purified by column
chromatography.
A solution of the corresponding allyl derivative (1 mmol) and
styrene (or methyl acrylate) (14 mmol) was treated with 2nd
generation Grubbs catalyst (12.5 mol %) and the resulting
mixture was stirred at reflux for 116 h. The reaction mixture
was filtered and the filtrate evaporated under reduced pressure
to give a residue that was purified by column chromatography
to furnish the pure product.

16
E. Marca et al. / Carbohydrate Research 382 (2013) 9–18
5.6.1. 2,3,4,6-Tetra-O-acetyl-b-
D-glucopyranosyl-(1?3)-1-
5.7.1. Benzyl b-D-Glucopyranosyl-(1?3)-b-D-glucopyranoside
deoxy-1-(4-methoxy-4-oxobutyl)-2,4,6-tri-O-acetyl-b-
D
-
(11a)
glucopyranose (15a)
Following the general procedure, the deacetylation of 10a
(0.102 g, 0.14 mmol) afforded 11a (71 mg, 98%) as an oil; HPLC:
Following the general procedure, the hydrogenation of 14a
(0.719 g, 1 mmol) afforded 15a (0.186 g, 94%) as a white solid;
t = 2.5 min (water/MeOH, 1:1); ½a D25
ꢁ
ꢂ46 (c 0.53, H2O); 1H NMR
mp 71–73 °C; Rf = 0.42 (hexane/EtOAc, 7:3); ½a D25
ꢁ
ꢂ15 (c 1.00,
(D2O, 400 MHz): d 3.21–3.42 (m, 7H, H2, H4, H5, H8, H9, H10,
CHCl3); 1H NMR (CDCl3, 400 MHz): d 1.38–1.53 (m, 2H, H13
,
H11), 3.57–3.66 (m, 3H, H3, H6a, H12a), 3.81 (ddd, 2H, J = 2.2,
H
13), 1.57–1.72 (m, 1H, H14a), 1.76–1.89 (m, 1H, H14b), 1.97 (s,
10.6, 12.7 Hz, H6b, H12b), 4.45 (d, 1H, J = 8.2 Hz, H1), 4.60 (d,
1H, J = 7.9 Hz, H7), 4.66 (d, 1H, J = 11.8 Hz, H13), 4.84 (d, 1H,
J = 11.7 Hz, H13), 7.28–7.38 (m, 5H); 13C NMR (D2O, 100 MHz):
d 60.6, 60.7, 68.2 (C4), 69.5 (C10), 71.5 (C13), 72.8 (C9), 73.4
(C8), 75.5 (C5), 75.5 (C2), 75.9 (C11), 84.5 (C3), 100.9 (C1),
102.8 (C7), 128.5 (Ar), 128.7 (Ar), 128.7 (Ar), 136.5 (Ar). Anal.
Calcd for C23H32O13: C, 53.49; H, 6.25. Found: C, 53.62; H, 6.08.
3H, Me), 2.00 (s, 3H, Me), 2.01 (s, 3H, Me), 2.02 (s, 3H, Me),
2.07 (s, 6H, Me), 2.13 (s, 3H, Me), 2.23–2.38 (m, 2H, H15),
3.23–3.29 (m, 1H, H1), 3.56 (ddd, 1H, J = 2.3, 5.0, 10.0 Hz, H5),
3.65 (s, 3H, OMe), 3.66–3.69 (m, 1H,
J = 9.4 Hz, H3), 4.01–4.13 (m, 2H, H6a
J = 5.1, 12.2 Hz, H6b), 4.38 (dd, 1H, J = 4.3, 12.4 Hz, H12b), 4.57
(d, 1H, J = 8.1 Hz, H7), 4.83–4.93 (m, 3H H2, H4, H8), 5.06 (t,
1H, J = 9.3 Hz, H10), 5.11 (t, 1H, J = 9.4 Hz, H9); 13C NMR (CDCl3,
100 MHz): d 20.3 (Me), 20.5 (Me), 20.5 (Me), 20.6 (C14), 20.8
(Me), 21.0 (Me), 30.3 (C13), 33.5 (C15), 51.5 (OMe), 61.7 (C12),
62.5 (C6), 68.0 (C10), 71.0 (C8), 71.7 (C11), 73.0 (C9), 73.6 (C2),
75.7 (C5), 77.7 (C1), 80.4 (C3), 101.0 (C7), 169.3 (C@O), 169.3
(C@O), 169.4 (C@O), 170.4 (C@O), 170.5 (C@O), 170.8 (C@O),
173.8 (C@O). Anal. Calcd for C31H44O19: C, 51.67; H, 6.15. Found:
C, 51.78; H, 5.97.
H
11), 3.82 (t, 1H,
,
H12a), 4.16 (dd, 1H,
5.7.2. 3-Phenylpropyl b-D-glucopyranosyl-(1?3)-b-D-
glucopyranoside (11b)
Following the general procedure, the deacetylation of 10b
(0.106 g, 0.14 mmol) afforded 11b (64 mg, 99%) as an oil; HPLC:
t = 4.3 min (water/MeOH, 1:1); ½a D25
ꢁ
ꢂ31 (c 1, H2O); 1H NMR
(D2O, 400 MHz): d 1.80–1.89 (m, 2H, H14), 2.60–2.66 (m, 2H,
H15), 3.23–3.43 (m, 8H, H2, H4, H5, H8, H9, H10, H11, H13a),
3.49–3.66 (m, 4H, H3, H6a, H12a, H13b), 3.78–3.83 (m, 2H, H6b
,
H
12b), 4.35 (d, 1H, J = 8.1 Hz, H1), 4.63 (d, 1H, J = 7.9 Hz, H7),
5.6.2. 2,3,4,6-Tetra-O-acetyl-b-
O-acetyl-b- -glucopyranosyl-(1?3)-1-(3-phenylpropyl)-1-
deoxy-2,4,6-tri-O-acetyl-b- -glucopyranose (15d)
D
-glucopyranosyl-(1?3)-2,4,6-tri-
7.14–7.29 (m, 5H, ArH); 13C NMR (D2O, 100 MHz):
d
30.5
D
(C15), 31.2 (C14), 60.6 (2C, C6, C12), 68.1 (C4), 69.5 (C10), 69.6
(C13), 72.8 (C9), 73.4 (C87), 75.5 (C5), 75.5 (C2), 76.0 (C11), 84.5
(C3), 101.9 (C1), 102.8 (C7), 126.0 (Ar), 128.6 (Ar), 142.2 (Ar).
Anal. Calcd for C21H32O11: C, 54.78; H, 7.00. Found: C, 54.63;
H, 6.87.
D
Following the general procedure, the hydrogenation of 14d
(1.03 g, 1 mmol) afforded 15d (0.198 g, 96%) as a white solid;
mp 90–92 °C; Rf = 0.27 (hexane/EtOAc, 2:3); ½a D25
ꢂ39 (c 0.51
ꢁ
CHCl3); 1H NMR (CDCl3, 400 MHz): d 1.39–1.49 (m, 2H, H19),
1.53–1.67 (m, 1H, H20a), 1.85–1.90 (m, 1H, H20b), 1.97 (s, 3H,
Me), 1.99 (s, 3H, Me), 2.01 (s, 3H, Me), 2.01 (s, 3H, Me), 2.03
(s, 3H, Me), 2.05 (s, 3H, Me), 2.07 (s, 3H, Me), 2.09 (s, 3H, Me),
2.10 (s, 3H, Me), 2.53–2.63 (m, 2H, H21), 3.21–3.28 (m, 1H, H1),
5.7.3. 5-Phenylpentyl b-D-glucopyranosyl-(1?3)-b-D-
glucopyranoside (11c)
Following the general procedure, the deacetylation of 10c
(0.110 g, 0.14 mmol) afforded 11c (67 mg, 98%) as an oil; HPLC:
3.55 (ddd, 1H, J = 2.2, 4.8, 10.0 Hz, H5), 3.62–3.69 (m, 2H, H11
,
,
t = 5.1 min (water/MeOH, 2:3); ½a D25
ꢁ
ꢂ24 (c 1.13, H2O); 1H NMR
H17), 3.74–3.84 (m, 2H, H3, H9), 4.00–4.12 (m, 3H, H6a, H12a
(D2O, 400 MHz): d 1.21–1.06 (m, 2H, H15a, H15b), 1.51–1.35
H
1a8), 4.15 (dd, 1H, J = 5.1, 12.3 Hz, H6b), 4.32 (dd, 1H, J = 4.5,
(m, 4H, H14a, H14b, H16a, H16b), 2.39 (t, J = 7.5 Hz, 2H, H17a
17b), 3.50–3.20 (m, 7H, H2, H4, H5, H8, H10, H11, H13a), 3.84–
3.53 (m, 7H, H3, H6a H6b H9, H12a H12b H13b), 4.23 (d,
J = 8.0 Hz, 1H, H1), 4.61 (d, J = 7.9 Hz, 1H, H7), 7.04–6.93 (m,
3H, ArH), 7.11–7.04 (m, 2H, ArH); 13C NMR (D2O, 100 MHz): d
24.9 (C15), 28.9 (C14), 30.7 (C16), 35.3 (C17), 60.7 (2C, C6, C12),
68.1 (C4), 69.5 (C10), 70.3 (C13), 72.8 (C2), 73.5 (C8), 75.4 (C9),
75.6 (C5 or C11), 76.0 (C5 or C11), 85.0 (C3), 102.0 (C1), 102.9
(C7), 125.6 (Ar), 128.3 (Ar), 128.4 (Ar), 142.8 (Ar). Anal. Calcd
for C23H36O11: C, 56.55; H, 7.43. Found: C, 56.75; H, 7.24.
,
12.4 Hz, H12b),4.39 (dd, 1H, J = 3.9, 12.4 Hz, H18b), 4.42 (d, 1H,
J = 8.1 Hz, H7), 4.49 (d, 1H, J = 8.1 Hz, H13), 4.82–4.94 (m, 5H,
H2, H4, H8, H10, H14), 5.06 (t, 1H, J = 9.6 Hz, H16), 5.11 (t, 1H,
J = 9.4 Hz, H15), 7.12–7.20 (m, 3H, ArH), 7.24–7.30 (m, 2H, ArH);
13C NMR (CDCl3, 100 MHz): d 20.3 (Me), 20.4 (Me), 20.5 (Me),
20.6 (Me), 20.7 (Me), 20.7 (Me), 20.8 (Me), 21.0 (Me), 26.7
(C20), 30.4 (C19), 35.4 (C21), 61.6 (C18), 62.0 (C12), 62.6 (C6),
68.0 (C16), 68.2 (C10 or C14), 68.6 (C10 or C14), 70.8 (C4), 71.6
(2C, C11,C17), 72.8 (C8), 73.8 (C2), 75.7 (C5), 77.1 (C1), 79.1 (C9),
79.9 (C3), 100.7 (C7), 101.1 (C13), 125.8 (Ar), 128.3 (Ar), 128.4
(Ar), 142.0 (Ar), 168.7 (C@O), 169.1 (C@O), 169.2 (C@O), 169.2
(C@O), 169.2 (C@O), 169.4 (C@O), 170.3 (C@O), 170.5 (C@O),
170.6 (C@O), 170.8 (C@O). Anal. Calcd for C47H62O25: C, 54.97;
H, 6.09. Found: C, 55.13; H, 6.21.
H
,
,
,
,
5.7.4. Furylmethyl b-D-glucopyranosyl-(1?3)-b-D-
glucopyranoside (11d)
Following the general procedure, the deacetylation of 10d
(0.1 g, 0.14 mmol) afforded 11d (58 mg, 98%) as an oil; HPLC:
t = 2.6 min (water/MeOH, 7:3);
NMR (D2O, 400 MHz): d 3.22–3.44 (m, 7H, H2, H4, H5, H8, H9,
½
a 2D5
ꢁ
ꢂ41 (c 0.69, H2O); 1H
5.7. General procedure for deacetylation
H
10, H11), 3.59–3.67 (m, 3H, H3, H6, H12), 3.79–3.83 (m, 2H,
A solution of the peracetylated derivative (0.14 mmol) in metha-
nol (10 mL) was treated with sodium methoxyde (10 mg,
0.19 mmol) and stirred at ambient temperature for 1.5 h. The reac-
tion mixture is then treated with dry Amberlyst 15 and the resulting
suspension is stirred for additional 25 min. The reaction mixture is
filtered through a pad of CeliteÒ and the filtrate was evaporated un-
der reduced pressure to give the crude product which was purified
by semipreparative HPLC (eluent: water–methanol) using a column
H6, H12), 4.45 (d, 1H, J = 8.1 Hz, H1), 4.61 (d, 1H, J = 7.9 Hz,
H7), 4.66 (d, 1H, J = 12.9 Hz, H13), 4.73 (d, 1H, J = 12.9 Hz,
ArH), 6.37 (dd, 1H, J = 1.9, 3.2 Hz, ArH), 6.44 (d, 1H, J = 3.2 Hz,
ArH), 7.46 (dd, 1H, J = 0.8, 1.9 Hz,
H
16); 13C NMR (D2O,
100 MHz): d 63.2 (2C, C6, C12), 65.5 (C13), 70.7 (C4), 72.1 (C10),
75.2 (C8), 75.9 (C9), 78.0 (C5 or C11), 78.5 (C5 or C11), 87.1
(C3), 103.0 (C1), 105.3 (2C, C6, C12), 113.2 (Ar), 113.4 (Ar),
146.4 (Ar), 152.6 (Ar). Anal. Calcd for C17H26O12: C, 48.34; H,
6.20. Found: C, 48.50; H, 6.36.
AtlantisÒ DC18 5
ELSD.
lm, 19 ꢀ 100 mm, flow: 12.5 mL/min. Detection:

E. Marca et al. / Carbohydrate Research 382 (2013) 9–18
17
5.7.5. Benzyl b-
D
-glucopyranosyl-(1?3)-b-
D
-glucopyranosyl-
ArH); 13C NMR (D2O, 100 MHz): d 26.5 (C20), 30.6 (C19), 34.9
(C21), 61.0 (C6 or C12 or C18), 61.1 (C6 or C12 or C18), 61.2 (C6
or C12 or C18), 68.8 (C4 or C10 or C16), 68.9 (C4 or C10 or C16),
70.0 (C4 or C10 or C16), 73.2 (C2 or C8 or C14), 74.2 (C2 or C8 or
(1?3)-b- -glucopyranoside (11e)
D
Following the general procedure, the deacetylation of 10e
(0.142 g, 0.14 mmol) afforded 11e (81 mg, 97%); oil; HPLC:
t = 3.0 min (water/MeOH, 1:1); ½a D25
ꢁ
ꢂ36 (c 0.51, H2O); 1H NMR
C14), 74.3 (C2 or C8 or C14), 76.2 (C5 or C11 or C17), 76.5 (C5 or
(D2O, 400 MHz): d 3.20–3.40 (m, 10H, H2, H4, H5, H8, H10, H11
,
C11 or C17), 76.7 (C5 or C11 or C17), 79.0 (C1), 79.7 (C15), 87.9
(C3 or C9), 88.5 (C3 or C9), 104.5 (C7), 105.0 (C13), 125.6 (Ar),
128.6 (2C, Ar), 143.1 (Ar). Anal. Calcd for C27H42O15: C, 53.46;
H, 6.98. Found: C, 53.65; H, 7.23.
H14, H15, H16, H17), 3.51–3.64 (m, 5H, H3, H6a, H9, H12a, H18a),
3.78–3.82 (m, 3H, H6b, H12b, H18b), 4.43 (d, 1H, J = 8.1 Hz, H1),
4.54 (d, 1H, J = 8.0 Hz, H7), 4.57 (d, 1H, J = 7.8 Hz, H13), 4.64 (d,
1H, J = 11.5 Hz, H19a), 4.81 (d, 1H, J = 11.6 Hz, H19b), 7.26–7.38 (m,
5H, ArH); 13C NMR (D2O, 100 MHz): d 60.6 (C6 or C12 or C18), 60.6
(C6 or C12 or C18), 60.7 (C6 or C12 or C18), 68.1 (C4 or C10), 68.2 (C4
or C10), 69.5 (C16), 71.5 (C13), 72.9 (C2), 73.2 (C8), 73.4 (C14), 75.5
(C5 or C11 or C17), 75.5 (C5 or C11 or C17), 75.6 (C5 or C11 or C17),
76.0 (C15), 84.2 (C9), 84.4 (C3), 100.9 (C1), 102.5 (C7), 102.8 (C13),
128.5 (Ar), 128.7 (Ar), 128.7 (Ar), 136.5 (Ar). Anal. Calcd for
5.8. General procedure for the one-pot preparation of free
oligosaccharides from 1-deoxy-1-allylglucosides
A solution of the corresponding allyl derivative (0.25 mmol)
and styrene (or methyl acrylate) (3.5 mmol) was treated with
2nd generation Grubbs catalyst (12.5 mol %) and the resulting
mixture was stirred at reflux for 116 h. The reaction mixture
was filtered and the filtrate evaporated under reduced pressure
to give a residue that was taken up in methanol (2 mL) and trea-
ted with Pearlman’s catalyst (15 mol %). The resulting mixture
was stirred under hydrogen (100 bar) at ambient temperature
for 2 h at which time the reaction mixture was filtered through
a pad of Celite. The filtrate was treated with sodium methoxide
(2.5 mg, 0.19 mmol) and stirred at ambient temperature for
1.5 h. The reaction mixture is then treated with dry Amberlyst
15 and the resulting suspension is stirred for additional
25 min. The reaction mixture is filtered through a pad of CeliteÒ
and the filtrate was evaporated under reduced pressure to give
the crude product which was purified by semipreparative HPLC
C25H38O16: C, 50.50; H, 6.44. Found: C, 50.67; H, 6.29.
5.7.6. 3-Phenylpropyl b-
glucopyranosyl-(1?3)-b-
D
-glucopyranosyl-(1?3)-b-
-glucopyranoside (11f)
D-
D
Following the general procedure, the deacetylation of 10f
(0.146 g, 0.14 mmol) afforded 11f (92 mg, 99%); oil; HPLC:
t = 7.7 min (water/MeOH, 1:1); ½a D25
ꢁ
ꢂ28 (c 0.56, H2O); 1H NMR
(D2O, 400 MHz): d 1.80–1.86 (m, 2H, H20a, H20b), 2.62 (t, 2H,
J = 7.6 Hz, H21), 3.25 (dd, 1H, J = 8.0, 9.4 Hz, H8), 3.22–3.5 (m, 9H,
H2, H4, H5, H10, H11, H14, H15, H16, H17), 3.55 (td, 1H, J = 6.6,
10.1 Hz, H19a), 3.59–3.68 (m, 5H, H3, H6a, H9, H12a, H18a), 3.78–
3.84 (m, 4H, H6b, H12b, H18b, H19b), 4.34 (d, 1H, J = 8.1 Hz, H1),
4.64 (d, 1H, J = 7.9 Hz, H13), 4.67 (d, 1H, J = 8.1 Hz, H7), 7.14–7.18
(m, 1H, ArH), 7.20–7.22 (m, 2H, ArH), 7.25–7.28 (m, 2H, ArH); 13C
(eluent: water–methanol) using
m, 19 ꢀ 100 mm, flow: 12.5 mL/min. Detection: ELSD.
a
column AtlantisÒ DC 18
NMR (D2O, 100 MHz): d 30.5 (C20), 31.2 (C21), 60.7 (3C, C6, C12
,
5 l
C18), 68.1 (C4 or C10), 68.2 (C4 or C10), 69.5 (C16), 69.6 (C19), 72.9
(C2), 73.5 (C8), 73.7 (C14), 75.5 (C5 or C11 or C17), 75.7 (C5 or C11
or C17), 75.7 (C5 or C11 or C17), 76.0 (C15), 85.0 (C9), 85.3 (C3),
102.0 (C1), 103.2 (C7), 103.3 (C13), 125.3 (Ar), 126.0 (Ar), 128.6
(Ar), 129.4 (Ar), 142.7 (Ar). Anal. Calcd for C29H44O17: C, 52.41; H,
6.67. Found: C, 52.63; H, 6.78.
5.8.1. b-D-Glucopyranosyl-(1?3)-1-deoxy-1-(3-phenylpropyl)-b-
D-glucopyranose (16b)
Following the general procedure, the one-pot procedure for 12
(0.165 g, 0.25 mmol) afforded 16b (44 mg, 40%) as a white foam;
HPLC: t = 2.0 min (MeOH); ½a D25
ꢁ
ꢂ18 (c 0.57, H2O); 1H NMR (D2O,
400 MHz): d 1.38 (dd, 1H, J = 9.0, 18.2 Hz, H13), 1.59–1.69 (m, 1H,
5.7.7. b-
D-Glucopyranosyl-(1?3)-1-deoxy-1-(4-methoxy-4-
H14), 1.70–1.82 (m, 2H, H13, H14), 2.58 (m, 2H, H15, H15), 3.21–3.47
oxobutyl)-b-
D
-glucopyranoside (16a)
(m, 8H, H1, H2, H4, H5, H8, H9, H10, H11), 3.55–3.65 (m, 3H, H3, H6,
H12), 3.79 (dd, 1H, J = 1.8, 12.2 Hz, H6), 3.83 (dd, 1H, J = 2.1,
12.3 Hz, H12), 4.64 (d, 1H, J = 7.9 Hz, H7), 7.15–7.18 (m, 1H, ArH),
7.21–7.22 (m, 2H, ArH), 7.26–7.29 (m, 2H, ArH); 13C NMR (D2O,
100 MHz): d 26.4 (C14), 30.4 (C13), 34.9 (C15), 60.7 (C12), 61.0 (C6),
68.6 (C4), 69.6 (C2), 73.1 (C8), 73.5 (C8), 75.6 (C10), 76.0 (C11), 78.9
(C1), 79.4 (C9), 86.4 (C3), 102.9 (C7), 125.9 (Ar), 128.5 (Ar), 128.6
(Ar), 143.0 (Ar). Anal. Calcd for C21H32O10: C, 56.75; H, 7.26. Found:
C, 56.88; H, 7.41.
Following the general procedure, the deacetylation of 15a
(0.101 g, 0.14 mmol) afforded 16a (58 mg, 97%); oil; HPLC:
t = 5.0 min (water/MeOH, 4:1); ½a D25
ꢁ
ꢂ20 (c 0.74, H2O); 1H NMR
(D2O, 400 MHz): d 1.33–1.42 (m, 1H, H13a), 1.57–1.68 (m, 1H,
H14a), 1.71–1.81 (m, 2H, H13b, H14b), 2.31–2.42 (m, 2H, H15),
3.22–3.47 (m, 8H, H1, H2, H4, H5, H8, H9, H10, H11), 3.57–3.66 (m,
6H, H3, H6a, H12a, OMe), 3.79–3.85 (m, 2H, H6b, H12b), 4.66 (d, 1H,
J = 7.9 Hz, H7); 13C NMR (D2O, 100 MHz): d 20.2 (C14), 30.0 (C13),
33.3 (C15), 52.1 (OMe), 60.7 (C6 or C12), 60.9 (C6 or C12), 68.5 (C4),
69.5 (C2), 72.9 (C5), 73.4 (C8), 75.5 (C10), 75.9 (C11), 78.7 (C1), 79.3
5.8.2. b- -glucopyranosyl-(1?3)-1-
D
-Glucopyranosyl-(1?3)-b-
D
(C9), 86.2 (C3), 102.8 (C7), 177.2 (C@O). Anal. Calcd for C17H30O12
:
deoxy-1-(4-methoxy-4-oxobutyl)-b-D-glucopyranoside (16c)
C, 47.88; H, 7.09. Found: C, 47.73; H, 6.87.
Following the general procedure, the one-pot procedure for
13 (0.237 g, 0.25 mmol) afforded 16c (93 mg, 52%) as an oil;
5.7.8. b-
deoxy-1-(3-phenylpropyl)-b-
D
-Glucopyranosyl-(1?3)-b-
D
-glucopyranosyl-(1?3)-1-
HPLC: t = 1.1 min (water/MeOH, 1:9); ½a D25
ꢂ12 (c 1.16 H2O);
ꢁ
D-glucopyranose (16d)
1H NMR (D2O, 400 MHz): d 1.27–1.36 (m, 1H, H20), 1.47–1.57
Following the general procedure, the deacetylation of 15d
(0.144 g, 0.14 mmol) afforded 16d (83 mg, 98%); oil; HPLC:
(m, 1H, H19), 1.61–1.75 (m, 2H, H19, H20), 2.04–2.16 (m, 2H,
H
H
H
21a, H21b), 3.18–3.43 (m, 14H, H1, H2, H4, H5, H8, H10, H11
14, H15, H16, H17, OMe), 3.49–3.62 (m, 5H, H3, H6, H9, H12
,
,
t = 1.5 min (water/MeOH, 1:9); ½a D25
ꢁ
ꢂ14 (c 1.35, H2O); 1H NMR
(D2O, 400 MHz): d 1.10–1.24 (m, 2H, H19a, H20a), 1.26–1.38 (m,
1H, H20b), 1.54–1.67 (m, 1H, H19b), 1.73–1.78 (m, 1H, H21a),
2.48–2.60 (m, 1H, H21b), 3.22–3.35 (m, 11H, H1, H2, H4, H5, H8,
18), 3.77–3.83 (m, 3H, H6, H12, H18), 4.54 (d, 1H, J = 8.1 Hz,
H7), 4.56 (d, 1H, J = 7.9 Hz, H13); 13C NMR (D2O, 100 MHz): d
21.8 (C20), 30.7 (C19), 37.3 (C21), 61.0 (C6 or C12 or C18), 61.1
(C6 or C12 or C18), 61.3 (C6 or C12 or C18), 68.7 (C4 or C10 or
H
H
10, H11, H14, H15, H16, H17), 3.49–3.60 (m, 5H, H3, H6a, H9,
12a, H18a), 3.75–3.82 (m, 3H, H6b, H12b, H18b), 4.51 (d, 1H,
C16), 68.8 (C4 or C10 or C16), 69.9 (C4 or C10 or C16), 73.1 (C2 or
J = 7.7 Hz, H7), 4.55 (d, 1H, J = 7.6 Hz, H13), 7.10–7.34 (m, 5H,
C8 or C14), 74.2 (C2 or C8 or C14), 74.2 (C2 or C8 or C14), 76.2

18
E. Marca et al. / Carbohydrate Research 382 (2013) 9–18
(C5 or C11 or C17), 76.5 (C5 or C11 or C17), 76.6 (C5 or C11 or C17),
79.0 (C1), 79.7 (C5), 87.7 (C3 or C9), 88.2 (C3 or C9), 104.4 (C13),
104.8 (C7), 183.6 (C@O). Anal. Calcd for C29H46O20: C, 48.74; H,
6.49. Found: C, 48.98; H, 6.26.
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Two
commercially
available
(Megazyme)
glucanases
(endo-b-1,3-glucanase (Barley) and endo-b-1,3(4)-
D
-glucanase from
Clostridum thermocellum) were assayed. An aliquot (0.5 mL, 1 unit/
mL of enzyme) is pre-equilibrated at 30 °C in the case of
endo-b-1,3-glucanase (Barley) or 60 °C in the case of endo-b-
1,3(4)-D-glucanase from Clostridum thermocellum for 5 min. A 1,3-
beta-GlucazymeÒ tablet (containing azurine-crosslinked pachy-
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the corresponding temperature for 10 min in the case of endo-
b-1,3-glucanase (Barley) and 3 h in the case of endo-b-1,3(4)-D-
glucanase from Clostridum thermocellum, at which time the reaction
mixture is treated with 10 mL of 100 mM TRIS buffer at pH 8 with
stirring. The resulting mixture is maintained at room temperature
and is stirred again for 5 min. The resulting slurry is filtered through
a Whatman No. 1 (9 cm) filter circle the absorbance of the filtrate is
measured at 590 nm against a substrate blank. The substrate blank
is prepared by adding a 1,3-beta-GlucazymeÒ tablet to 0.5 mL of
extraction buffer, incubating at 30 °C for 10 min, adding 10.0 mL
of Trizma Base (2% w/v) and filtering after 5 min.
Several measures of glucanase activities were made in the pres-
ence of various concentrations (10, 50 and 100 mM) of compounds
11a–f and 16a–d and in all cases the observed activity was identi-
cal to that in their absence indicating the complete absence of
inhibitory activity.
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This study was supported by the Ministerio de Ciencia e Innova-
ción (MICINN) and FEDER Program (Madrid, Spain, projects
CTQ2010-19606 and BFU2010-19504), and the Gobierno de Aragón
(Zaragoza, Spain. Bioorganic Chemistry Group. E-10). E.M. and
J.V.G. thank MEC for FPU and FPI predoctoral grants, respectively.