Fast oxidation of thioglycosides to glycosyl sulfones using KMnO 4/CuSO4·5H2O under neutral reaction conditions

Article abstract of DOI:10.1016/j.carres.2005.11.025

A rapid oxidation of thioglycosides to glycosyl sulfones has been achieved using a combination of KMnO₄ and CuSO₄·5H ₂O in acetonitrile and water. This reaction protocol has many advantages compared to other methods availa

Full text of DOI:10.1016/j.carres.2005.11.025

Carbohydrate
RESEARCH
Carbohydrate Research 341 (2006) 275–280
Note
Fast oxidation of thioglycosides to glycosyl sulfones using
KMnO4/CuSO4Æ5H2O under neutral reaction conditionsI
Geetanjali Agnihotri and Anup Kumar Misra*
Division of Medicinal and Process Chemistry, Central Drug Research Institute (CDRI), Chattar Manzil Palace,
Lucknow 226001, India
Received 2 October 2005; received in revised form 23 November 2005; accepted 25 November 2005
Available online 15 December 2005
Abstract—A rapid oxidation of thioglycosides to glycosyl sulfones has been achieved using a combination of KMnO4 and
CuSO4Æ5H2O in acetonitrile and water. This reaction protocol has many advantages compared to other methods available for this
transformation, including compatibility with acid and base labile functional groups used for the protection of carbohydrates, high
yields, fast reaction times, and moderate reaction temperatures. The yields obtained were excellent in all cases.
Ó 2005 Elsevier Ltd. All rights reserved.
Keywords: Carbohydrates; Sulfones; Oxidation; KMnO4; CuSO4Æ5H2O; Thioglycosides
Sulfones are an important class of synthetic intermedi-
ates, which are, for example, used for C–C bond forma-
number of methods are available for the oxidation of
sulfides to sulfones, fewer methods for the preparation
of glycosyl sulfones have been investigated. These
include the use of m-chloroperoxybenzoic acid (m-CPBA),
magnesium bis(monoperoxyphthalate) (MMPP),27
dimethyldioxirane (DMDO),16 KMnO4/acetic acid,28
and RuCl3/NaIO4.6 In general, the oxidation of thiogly-
cosides to sulfones has been achieved most successfully
using m-CPBA. However, this method suffers from
number of shortcomings including partial solubility of
m-CPBA in dichloromethane and difficulty in removing
the byproduct (m-chlorobenzoic acid) from the sulfone.
Other methods for the oxidation of thioglycosides into
glycosyl sulfones also have notable drawbacks such as
strongly acidic reaction conditions or the requirement
of high temperatures. Therefore, there is a need to devel-
op mild oxidation protocols for the transformation of
thioglycosides to glycosyl sulfones that circumvent the
aforementioned drawbacks. Our efforts to prepare
several glycosyl sulfones using of m-CPBA and aqueous
KMnO4/AcOH or H2O2/AcOH reaction conditions
always resulted in the removal of acid labile functional
groups and in some cases deacetylated products.
tion
and
stereocontrolled
functional
group
transformations.1–4 In carbohydrate chemistry, glycosyl
sulfones have been used for the preparation of function-
alized glycals as well as O- and C-glycosides.5–11 A num-
ber of biologically important oligosaccharides having
C-glycosyl linkages have been synthesized using glycosyl
sulfones under samarium mediated reductive reaction
conditions with excellent anomeric stereocontrol.12–15
Apart from being used as glycosyl donors, glycosyl sul-
fones have also been used as potential glycosyltransfer-
ase inhibitors.16
In view of the importance of sulfones, several oxidiz-
ing agents have been reported for the oxidation of sul-
fides into sulfones,17 including m-chloroperoxybenzoic
acid (m-CPBA),18 aqueous KMnO4,19 potassium hydro-
gen sulfate (KHSO5),20 hydrogen peroxide–acetic acid,21
peroxytrifluoroacetic acid,22 tetra-n-butylammonium
oxone,23 osmium tetroxide (OsO4),24 PhIO/RuCl2-
(PPh3)3,25 and RuCl3/NaIO4, or HIO4.26 Although a
q CDRI Communication No. 6888.
Prompted by a recent paper29 in which solid KMnO4
in combination with CuSO4Æ5H2O has been successfully
*
Corresponding author. Tel.: +91 522262411; fax: +91 5222623405;
e-mail: akmisra69@rediffmail.com
0008-6215/$ - see front matter Ó 2005 Elsevier Ltd. All rights reserved.
doi:10.1016/j.carres.2005.11.025

276
G. Agnihotri, A. K. Misra / Carbohydrate Research 341 (2006) 275–280
employed for the preparation of disulfides and sulfones
under solvent-free reaction conditions, we envisaged
that this combination could oxidize thioglycosides to
sulfones under neutral reaction conditions thus avoiding
the chance for the removal of acid labile protecting
groups. Earlier, the KMnO4/CuSO4Æ5H2O combination
has been successfully employed for oxidation of alcohols
and preparation of lactones.30 We describe here, a con-
venient reaction protocol for the preparation of glycosyl
sulfones under neutral reaction conditions using a com-
bination of KMnO4/CuSO4Æ5H2O.
pared by the oxidation of differentially functionalized
thioglycosides using a combination of solid KMnO4
and CuSO4Æ5H2O under neutral conditions. The method
is compatible with acid and base labile functional groups
used for the protection of carbohydrates, and is high
yielding and fast. In addition, the ease of product isola-
tion makes this reaction protocol as an attractive alter-
native to those existing in the literature. Samarium
iodide mediated preparation of C-glycosides using gly-
cosyl sulfones is underway in our laboratory.
For our initial studies, a solution of phenyl 2,3,4,6-
tetra-O-acetyl-1-thio-b-D-glucopyranoside in dichloro-
methane was treated with solid KMnO4 (2.0 equiv) at
room temperature. The formation of the corresponding
glycosyl sulfone was very slow and the reaction did not
furnish an acceptable yield of the product. While per-
forming the reaction in acetone the reaction proceeded
well but did not reach completion. Gratifyingly, the
reaction was complete in a few minutes when the same
reaction was carried out at room temperature using a
1:1 mixture of KMnO4 and CuSO4Æ5H2O in CH3CN–
H2O (5:1) and the yield was almost quantitative. After
some experimentation, it was observed that the use of
a finely powdered premixed combination of KMnO4
and CuSO4Æ5H2O (1.5:1 molar ratio) in CH3CN–H2O
(5:1) at room temperature successfully oxidized several
thioglycosides to the corresponding glycosyl sulfones
in excellent yield (Scheme 1). It is worth noting that
the addition of CuSO4Æ5H2O separately after the addi-
tion of KMnO4 led to incomplete oxidation. Acid labile
functional groups (e.g., benzylidene acetal, isopropylid-
ene acetal, and TBDMS) used for the temporary protec-
tion of hydroxyl groups of sugar derivatives were stable
to the reaction conditions. It is important to mention
that use of CuSO4Æ5H2O premixed with KMnO4 is
essential for the completion of the reaction. Although
earlier KMnO4 in acetic acid at higher temperatures
has been used for the preparation of glycosyl sulfones,
the reaction condition was very harsh and cannot be
applied for the oxidation of thioglycosides containing
acid labile functional groups. Among the solvents
explored (e.g., dichloromethane, 1,2-dichloroethane,
nitromethane, THF, CH3CN, and acetone), the aceto-
nitrile–water combination was found to be the most
effective in producing high yields of the product.
1. Experimental
1.1. General methods
The general methods are the same as previously
reported.34
1.2. Typical experimental protocol for the preparation of
glycosyl sulfones
To a solution of thioglycoside (1.0 mmol) in CH3CN–
H2O (5:1 v/v; 10 mL) was added a finely ground mixture
of solid KMnO4 and CuSO4Æ5H2O (1.5:1 molar ratio;
500 mg) and the reaction mixture was stirred at room
temperature for appropriate time period(Table 1). After
completion of the reaction (TLC; hexane–EtOAc 1:1),
the reaction mixture concentrated under reduced pres-
sure and the crude mass was extracted with CH2Cl2.
The organic layer was washed with water, dried
(Na2SO4), and concentrated under reduced pressure to
furnish an almost pure product (Table 1). Analytical
samples were prepared by purification over SiO2 using
hexane–EtOAc as eluant. All known compounds gave
acceptable 1H NMR and 13C NMR spectra that
matched data reported in the cited references.
1.2.1. Phenyl 2,3,4,6-tetra-O-acetyl-1-sulfonyl-b-D-galac-
25
topyranoside (2b). Oil; ½aꢀD ꢁ15 (c 1.2, CHCl3); 1H
NMR (CDCl3, 200 MHz): d 7.98–7.56 (m, 5H, aro-
matic), 5.45 (t, J = 9.8 Hz, 1H), 5.31 (d, J = 3.5 Hz,
1H), 5.04 (dd, J = 9.8, 3.1 Hz, 1H), 4.50 (d,
J = 9.7 Hz, 1H), 4.14–4.03 (m, 1H), 3.98–3.88 (m, 2H),
2.14, 1.98, 1.97, 1.89 (4s, 12H, 4COCH3); IR (Neat):
2363, 1751, 1222, 1080, 758 cmꢁ1; ESI-MS: m/z = 495
[M+Na]. Anal. Calcd for C20H24O11S: C, 50.84; H,
5.12. Found: C, 51.02; H, 5.35.
In summary, a series of glycosyl sulfones having a
variety of functional groups have been successfully pre-
OR1
OR1
.
KMnO4/CuSO4 5H2O
R1O
R1O
R1O
O
O
SR2
R1O
SO2R2
CH3CN-H2O (5:1)
OR1
OR1
Scheme 1.

G. Agnihotri, A. K. Misra / Carbohydrate Research 341 (2006) 275–280
277
Table 1. Oxidation of thioglycosides to glycosyl sulfones using KMnO4 and CuSO4Æ5H2O in CH3CN–H2O at room temperature
Entry
Thioglycoside (1)
Sulfone (2)
Time (min)
Yield (%)
Ref.
OAc
OAc
AcO
AcO
AcO
AcO
O
O
a
30
95
28
SPh
SO2Ph
OAc
OAc
OAc
OAc
OAc
OAc
O
O
b
c
d
e
f
30
45
45
25
30
25
30
30
30
95
92
96
92
90
88
90
92
85
—
—
—
31
28
—
—
—
5
AcO
BzO
AcO
BzO
SO2Ph
SO2Ph
SPh
OAc
OAc
OBz
O
OBz
O
BzO
BzO
SPh
OBz
OBz
BzO
BzO
BzO
BzO
OBz
OBz
O
O
SPh
SO2Ph
SO2Ph
OBz
OBz
OBn
O
OBn
O
BnO
BnO
BnO
BnO
SPh
OBn
OBn
AcO
AcO
AcO
AcO
O
O
SO2Ph
SPh
OAc
OAc
SPh
OBn
SO2Ph
OBn
O
O
Me
Me
g
h
i
OBn
OBn
BnO
BnO
AcO
AcO
AcO
OAc
O
AcO
AcO
AcO
OAc
O
SO2Et
SEt
OAc
OAc
AcO
AcO
AcO
AcO
O
O
SEt
SO2Et
OAc
OAc
Ph
O
Ph
O
O
O
j
O
O
AcO
AcO
SO2Ph
SPh
OAc
OAc
O
O
Ph
Ph
O
O
O
O
k
30
90
—
AcO
AcO
SPh
SO2Ph
OAc
OAc
OTBDPS
O
OTBDPS
O
BzO
BzO
BzO
BzO
l
25
60
90
85
—
—
SEt
SO2Et
OBz
OBz
OAc
OAc
O
O
AcO
AcO
O
AcO
AcO
m
OEt
OEt
S
S
(continued on next page)
O
O
OAc
OAc
O

278
G. Agnihotri, A. K. Misra / Carbohydrate Research 341 (2006) 275–280
Table 1 (continued)
Entry
Thioglycoside (1)
OAc
Sulfone (2)
Time (min)
Yield (%)
92
Ref.
—
OAc
AcO
AcO
AcO
AcO
O
O
n
45
45
SPh
SO2Ph
NPhth
NPhth
AcO
AcO
OAc
OAc
COOMe
SPh
COOMe
AcO
AcHN
o
p
q
AcO
85
95
92
32
6
O
O
SO2Ph
AcHN
AcO
AcO
O
O
O
OAc
OAc
O
O
30
45
O
O
SPh
SO2Ph
OAc
OAc
OAc
O
O
O
OAc
OAc
OAc
O
O
O
O
5
SO2Ph
SO2Ph
SPh
O
O
AcO
AcO
OAc
OAc
OAc
OAc
OAc
OAc
OAc
O
OAc
O
OAc
OAc
O
r
s
45
45
95
95
33
—
O
O
O
AcO
AcO
AcO
AcO
SPh
AcO
AcO
AcO
OAc
OAc
OAc
OAc
O
O
AcO
OAc
OAc
AcO
AcO
O
O
AcO
AcO
O
O
AcO
SO2Ph
SPh
AcO
OAc
OAc
1.2.2. Phenyl 2,3,4,6-tetra-O-benzoyl-1-sulfonyl-b-D-
glucopyranoside (2c). White solid; mp 175–177 °C;
matic), 5.46 (d, J = 2.1 Hz, 1H), 5.37 (dd, J = 9.6,
3.0 Hz, 1H), 4.94 (d, J = 9.9 Hz, 1H), 4.59–4.53
(m, 5H), 4.52–4.39 (m, 2H), 3.75–3.73 (m, 1H), 1.02
(d, J = 6.0 Hz, 3H); IR (Neat): 2922, 2364, 1726, 1275,
1100, 757 cmꢁ1; ESI-MS: m/z = 581 [M+Na]. Anal.
Calcd for C33H34O6S: C, 70.94; H, 6.13. Found: C,
70.70; H, 6.40.
25
1
½aꢀD +2.4 (c 1.2, CHCl3); H NMR (CDCl3, 200 MHz):
d 7.99–7.26 (m, 25H, aromatic), 5.91 (t, J = 9.3 Hz,
1H), 5.87 (t, J = 9.6 Hz, 1H), 5.50 (t, J = 9.6 Hz, 1H),
4.87 (d, J = 9.6 Hz, 1H), 4.60 (d, J = 11.7 Hz, 1H),
4.38 (dd, J = 12.3, 4.8 Hz, 1H), 4.20–4.17 (m, 1H); IR
(KBr): 2366, 1732, 1590, 1263, 1106, 718 cmꢁ1; ESI-
MS: m/z = 743 [M+Na]. Anal. Calcd for C40H32O11S:
C, 66.66; H, 4.48. Found: C, 66.48; H, 4.70.
1.2.5. Ethyl 2,3,4,6-tetra-O-acetyl-1-sulfonyl-a-D-manno-
25
pyranoside (2h). White solid; mp 101–103 °C; ½aꢀD
1
+39.6 (c 1.2, CHCl3); H NMR (CDCl3, 200 MHz): d
1.2.3. Phenyl 2,3,4,6-tetra-O-benzoyl-1-sulfonyl-b-D-
galactopyranoside (2d). White solid; mp 168 °C;
5.90 (br s, 1H), 5.54 (dd, J = 9.0, 3.5 Hz, 1H), 5.24 (t,
J = 9.4 Hz, 1H), 4.81 (br s, 1H), 4.66–4.59 (m, 1H),
4.27 (dd, J = 12.4, 5.4 Hz, 1H), 4.12 (dd, J = 12.4,
1.7 Hz, 1H), 3.14 (q, J = 7.4 Hz, 2H), 2.17, 2.09, 2.06,
2.02 (4s, 12H, 4COCH3), 1.44 (t, J = 7.4 Hz, 3H); IR
(KBr): 2922, 2363, 1748, 1219, 768 cmꢁ1; ESI-MS:
m/z = 447 [M+Na]. Anal. Calcd for C16H24O11S: C,
45.28; H, 5.70. Found: C, 45.04; H, 6.0.
25
1
½aꢀD +36 (c 1.2, CHCl3); H NMR (CDCl3, 200 MHz):
d 8.08–7.26 (m, 25H, aromatic), 6.01 (t, J = 9.8 Hz,
1H), 5.94 (d, J = 3.9 Hz, 1H), 5.58 (dd, J = 9.8,
3.1 Hz, 1H), 4.93 (d, J = 9.9 Hz, 1H), 4.60 (dd,
J = 10.8, 6.2 Hz, 1H), 4.50 (t, J = 6.0 Hz, 1H), 4/28
(dd, J = 10.8, 5.6 Hz, 1H); IR (KBr): 2363, 1727, 1593,
1256, 1099, 711 cmꢁ1; ESI-MS: m/z = 743 [M+Na].
Anal. Calcd for C40H32O11S: C, 66.66; H, 4.48. Found:
C, 66.40; H, 4.70.
1.2.6. Ethyl 2,3,4,6-tetra-O-acetyl-1-sulfonyl-b-D-gluco-
25
pyranoside (2i). White solid; mp 153–154 °C; ½aꢀD
1
ꢁ16.2 (c 1.2, CHCl3); H NMR (CDCl3, 200 MHz): d
1.2.4. Phenyl 2,3,4-tri-O-benzyl-6-deoxy-1-sulfonyl-b-L-
5.48 (t, J = 9.6 Hz, 1H), 5.31 (t, J = 9.3 Hz, 1H), 5.12
(t, J = 9.6 Hz, 1H), 4.45 (d, J = 9.9 Hz, 1H), 4.30–4.18
(m, 2H), 3.85–3.81 (m, 1H), 3.19–3.09 (m, 2H,
25
galactopyranoside (2g). Oil; ½aꢀD ꢁ63 (c 1.2, CHCl3);
1H NMR (CDCl3, 200 MHz): d 7.97–7.04 (m, 20H, aro-

G. Agnihotri, A. K. Misra / Carbohydrate Research 341 (2006) 275–280
279
SCH2CH3), 2.09, 2.07, 2.05, 2.03 (4s, 12H, 4COCH3),
1.40 (t, J = 7.5 Hz, 3H, SCH2CH3); IR (KBr): 2947,
1748, 1228, 1111, 1037, 722, 595 cmꢁ1; ESI-MS: m/z =
447 [M+Na]. Anal. Calcd for C16H24O11S: C, 45.28;
H, 5.70. Found: C, 45.05; H, 5.97.
200 MHz): d 7.91–7.53 (m, 5H, aromatic), 5.32–5.30
(m, 1H), 5.28–5.23 (m, 1H), 4.85–4.78 (m, 1H), 4.46
(d, J = 9.6 Hz, 1H), 4.41 (br s, 1H), 4.32–4.25 (m, 3H),
4.13–4.04 (m, 3H), 3.92–3.86 (m, 1H), 3.65–3.60 (m,
2H), 2.11, 2.09, 2.04, 2.03, 1.97 (5s, 15H, 5COCH3),
1.50, 1.30 (2s, 6H); IR (KBr): 2992, 2363, 1753, 1592,
1.2.7. Phenyl 2,3-di-O-acetyl-4,6-O-benzylidene-1-sulfon-
yl-b-D-glucopyranoside (2k). White solid; mp 189–
1378, 1230, 1051, 590 cmꢁ1
; ESI-MS: m/z = 739
[M+Na]. Anal. Calcd for C31H40O17S: C, 51.95; H,
5.63. Found: C, 51.75; H, 5.90.
25
1
190 °C, ½aꢀD ꢁ73.2 (c 1.2, CHCl3); H NMR (CDCl3,
200 MHz): d 7.94–7.26 (m, 10H, aromatic), 5.42 (s,
1H), 5.36–5.28 (m, 2H), 4.60 (d, J = 9.5 Hz, 1H), 4.30
(dd, J = 7.9, 3.3 Hz, 1H), 3.70–3.51 (m, 3H), 2.10, 2.03
(2s, 6H, 2COCH3); IR (KBr): 2926, 1757, 1372, 1234,
1083, 760 cmꢁ1; ESI-MS: m/z = 499 [M+Na]. Anal.
Calcd for C23H24O9S: C, 57.97; H, 5.08. Found: C,
57.75; H, 5.30.
1.2.12. Phenyl 2,3,4,6-tetra-O-acetyl-a-D-glucopyranosyl-
(1!4)-2,3,6-tri-O-acetyl-1-sulfonyl-b-D-glucopyranoside
25
1
(2s). Oil; ½aꢀD +51 (c 1.2, CHCl3); H NMR (CDCl3,
200 MHz): d 7.90–7.55 (m, 5H, aromatic), 5.35–5.28
(m, 2H), 5.12 (t, J = 9.3 Hz, 1H), 5.02 (t, J = 9.9 Hz,
1H), 4.82 (dd, J = 10.5, 3.9 Hz, 1H), 4.54 (d,
J = 10.2 Hz, 2H), 4.20 (dd, J = 12.0, 3.6 Hz, 1H),
4.14–4.08 (m, 1H), 4.02 (d, J = 12.6 Hz, 1H), 3.82 (t,
J = 9.3 Hz, 2H), 3.70–3.67 (m, 2H), 2.10, 2.08, 2.03,
2.01, 2.00 (5s, 21H, 7COCH3); IR (Neat): 2928, 1753,
1235, 1038, 760 cmꢁ1; ESI-MS: m/z = 783 [M+Na].
Anal. Calcd for C32H40O19S: C, 50.52; H, 5.30. Found:
C, 50.30; H, 5.50.
1.2.8. Ethyl 2,3,4-tri-O-benzoyl-6-O-tert-butyldiphenyl-
silyl-1-sulfonyl-b-D-glucopyranoside (2l). White solid;
25
mp 156–158 °C, ½aꢀD +9 (c 1.2, CHCl3); 1H NMR
(CDCl3, 200 MHz): d 7.96–7.21 (m, 25H, aromatic),
6.02 (t, J = 9.1 Hz, 1H), 5.91 (t, J = 9.0 Hz, 1H), 5.72
(t, J = 9.5 Hz, 1H), 4.78 (d, J = 9.0 Hz, 1H), 4.01–3.94
(m, 1H), 3.91–3.86 (m, 2H), 3.20 (q, J = 15.0, 6.0 Hz,
2H), 1.40 (t, J = 7.5 Hz, 3H), 1.04 (s, 9H); IR (KBr):
2929, 1736, 1262, 1105, 707 cmꢁ1; ESI-MS: m/z = 829
[M+Na]. Anal. Calcd for C45H46O10SSi: C, 66.97; H,
5.75. Found: C, 66.70; H, 6.0.
Acknowledgements
Instrumentation facilities from SAIF and CDRI are
gratefully acknowledged. G.A. thanks CSIR, New
Delhi, for providing a senior research fellowship. This
project is funded by the Department of Science and
Technology (DST), New Delhi (SR/FTP/CSA-10/
2002), India.
1.2.9. Ethoxycarbonylmethyl 2,3,4,6-tetra-O-acetyl-1-sul-
fonyl-b-D-glucopyranoside
(2m). White
powder;
25
½aꢀD ꢁ22.2 (c 1.2, CHCl3); 1H NMR (CDCl3, 200
MHz): d 5.53 (t, J = 9.8 Hz, 1H), 5.30 (t, J = 9.2 Hz,
1H), 5.10 (t, J = 9.8 Hz, 1H), 4.88 (d, J = 9.9 Hz, 1H),
4.33 (d, J = 15 Hz, 1H), 4.30–4.22 (m, 4H), 3.87–3.80
(m, 2H), 2.08, 2.05, 2.04, 2.03 (4s, 12H, 4COCH3),
1.39–1.32 (t, J = 7.1 Hz, 3H); IR (KBr): 2960, 2363,
1750, 1594, 1350, 1224 cmꢁ1; ESI-MS: m/z = 505
[M+Na]. Anal. Calcd for C18H26O13S: C, 44.81; H,
5.43. Found: C, 44.57; H, 5.55.
References
1. Jeong, Y. C.; Ji, M.; Lee, J. S.; Yang, J.-D.; Jin, J.; Baik,
W.; Koo, S. Tetrahedron 2004, 60, 10181–10185.
2. Harris, J. M.; OꢀDoherty, G. A. Tetrahedron 1998, 54,
1601–1614.
3. Dherde, J. N. P.; De Clercq, P. J. Tetrahedron Lett. 2003,
44, 6657–6659.
4. Adrio, J.; Carretero, J. C. Tetrahedron 1998, 54, 1601–
1614.
1.2.10. Phenyl 3,4,6-tri-O-acetyl-2-deoxy-2-phthalimido-
25
1-sulfonyl-b-D-glucopyranoside (2n). Oil; ½aꢀD +13 (c
1
1.2, CHCl3); H NMR (CDCl3, 200 MHz): d 7.91–7.56
(m, 9H, aromatic), 5.76 (t, J = 9.6 Hz, 1H), 5.45 (d,
J = 10.5 Hz, 1H), 4.99 (t, J = 9.6 Hz, 1H), 4.55 (t,
J = 10.2 Hz, 1H), 4.26–4.09 (m, 2H), 2.01, 1.87 (2s,
9H, 3COCH3); IR (Neat): 2924, 2363, 1750, 1722,
1383, 1224, 768 cmꢁ1; ESI-MS: m/z = 582 [M+Na].
Anal. Calcd for C26H25NO11S: C, 55.81; H, 4.50.
Found: C, 55.60; H, 4.79.
´
´
5. de Pouilly, P.; Chenede, A.; Mallet, J.-M.; Sinay, P.
¨
Tetrahedron Lett. 1992, 33, 8065–8068.
6. Fernandez-Mayoralas, A.; Marra, A.; Trumtel, M.;
`
Veyrieres, A.; Sinay, P. Carbohydr. Res. 1989, 188, 81–
¨
95.
´
7. Somsak, L. Chem. Rev. 2001, 101, 81–136.
8. Belica, P. S.; Franck, R. W. Tetrahedron Lett. 1998, 39,
8225–8228.
9. Ohnishi, Y.; Ichikawa, Y. Bioorg. Med. Chem. Lett. 2002,
12, 997–999.
10. Beau, J.-M.; Sinay, P. Tetrahedron Lett. 1985, 26, 6193–
1.2.11. Phenyl 2,6-di-O-acetyl-3,4-O-isopropylidene-b-D-
galactopyranosyl-(1!4)-2,3,6-tri-O-acetyl-1-sulfonyl-b-
D-glucopyranoside (2q). White solid; mp 95–97 °C;
¨
6196.
11. Dondoni, A.; Marra, A. Chem. Rev. 2000, 100, 4392–
25
½aꢀD +5.4 (c 1.2, CHCl3); 1H NMR (CDCl3,
4422.

280
G. Agnihotri, A. K. Misra / Carbohydrate Research 341 (2006) 275–280
12. Wang, Q.; Linhardt, R. J. J. Org. Chem. 2003, 68, 2668–
23. Trost, B. M.; Braslau, R. J. Org. Chem. 1988, 53, 532–
537.
2672.
´
13. Mikkelsen, L. M.; Krintel, S. L.; Jimenez-Barbero, J.;
24. Kaldor, S. W.; Hammond, M. Tetrahedron Lett. 1991, 32,
5043–5046.
25. Muller, P.; Godoy, J. Helv. Chim. Acta 1983, 66, 1790–
1795.
Skrydstrup, T. J. Org. Chem. 2002, 67, 6297–6308.
14. Vlahov, I. R.; Vlahova, P. I.; Linhardt, R. J. J. Am. Chem.
Soc. 1997, 119, 1480–1481.
´
15. Mazeas, D.; Skrydstrup, T.; Doumeix, O.; Beau, J.-M.
26. Rodriguez, C. M.; Ode, J. M.; Palazoe, M. I.; Martin, V.
S. Tetrahedron 1992, 48, 3571–3576.
27. Arjona, O.; Menchaca, R.; Plumet, J. Tetrahedron 2001,
57, 6751–6755.
Angew. Chem., Int. Ed. Engl. 1994, 33, 1383–1386.
16. Gervay, J.; Flaherty, T. M.; Holmes, D. Tetrahedron 1997,
53, 16355–16364.
17. Uemura, S. In Oxidation of Sulfur, Selenium and Tellu-
rium. In Comprehensive Organic Synthesis; Trost, B. M.,
Ed.; Pergamon Press, 1991; Vol. 7, pp 766–769.
18. Brown, D. J.; Ford, P. W. J. Chem. Soc. C 1969, 2720–
2723.
19. Fatiadi, A. J. Synthesis 1987, 85–127.
20. Trost, B. M.; Curran, D. P. Tetrahedron Lett. 1981, 22,
1287–1290.
28. Bonner, W. A.; Drisko, R. W. J. Am. Chem. Soc. 1948, 70,
2435–2438.
29. Shaabani, A.; Lee, D. G. Tetrahedron Lett. 2001, 42,
5833–5836.
30. Jefford, C. W.; Wang, Y. J. Chem. Soc., Chem. Commun.
1988, 634–635.
31. Ferrier, R. J.; Furneaux, R. H.; Tyler, P. C. Carbohydr.
Res. 1977, 58, 397–404.
21. Gilman, H.; Beaber, N. J. J. Am. Chem. Soc. 1925, 47,
1449–1451.
32. Marra, A.; Sinay, P. Carbohydr. Res. 1989, 187, 35–42.
33. Funabashi, M.; Nagashima, H. Chem. Lett. 1987, 2065–
¨
22. Venier, C. G.; Squires, T. G.; Chen, Y.-Y.; Hussmann, G.
P.; Shei, J. C.; Smith, B. F. J. Org. Chem. 1982, 47, 3773–
3774.
2068.
34. Agnihotri, G.; Tiwari, P.; Misra, A. K. Carbohydr. Res.
2005, 340, 1393–1396.