Dimethyltin Dichloride Catalyzed Regioselective Alkylation of cis-1,2-Diols at Room Temperature

Article abstract of DOI:10.1021/acs.joc.5b01898

Here, we have developed a mild and general method for the regioselective installation of benzyl, allyl, para-methoxybenzyl and naphthyl groups on cis-1,2-diols. The optimized method operates at room temperature using dimethyltin dichloride as catalyst and

Full text of DOI:10.1021/acs.joc.5b01898

Article
pubs.acs.org/joc
Dimethyltin Dichloride Catalyzed Regioselective Alkylation of cis-1,2-
Diols at Room Temperature
Varma Saikam,†,‡ Saidulu Dara,†,‡ Mahipal Yadav,† Parvinder Pal Singh,*,†,‡ and Ram A. Vishwakarma*,†,‡
†Medicinal Chemistry Division, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu 180 001, India
‡Academy of Scientific and Innovative Research, Jammu 180001, India
S
* Supporting Information
ABSTRACT: Here, we have developed a mild and general method for the regioselective installation of benzyl, allyl, para-
methoxybenzyl and naphthyl groups on cis-1,2-diols. The optimized method operates at room temperature using dimethyltin
dichloride as catalyst and silver oxide as an additive. The present method works well with both sugars (such as mono- and
disaccharides) and nonsugars (such as inositols, propan-1,2-diol, 1,2-cycloalkanediols and anhydroerythritol) and also provides
comparatively better functional group compatibility.
glycosylation8d at room temperature; however, there is no
INTRODUCTION
■
report regarding its use in the alkylation at room temperature.
Regioselective protection of sugars with orthogonal protecting
In this endeavor, we envisioned that the same could be
groups plays a key role in the successful synthesis of
explored for the alkylation in the presence of suitable additive.
oligosaccharides and complex glyco-conjugates.1 In this
Considering our interest in carbohydrate chemistry9 and
direction, benzyl ethers and its variants, which represent an
importance of mild alkylation methods, we have successfully
important orthogonal protecting group, are frequently used in
developed a room-temperature, regioselective method for the
the carbohydrate chemistry because of following advantages
alkylation of the cis-1,2-diols using dimethyltin dichloride as
such as easy installation, stability, compatibility with many
catalyst and silver oxide as an additive. The present method
reaction conditions and smooth removal under milder
successfully used for the installation of benzyl group and its
conditions.2 Considering the differential reactivity of equatorial
variants such as allyl, p-methoxybenzyl and naphthyl to a wide
and axial hydroxyl groups of sugars, many approaches have
range of monosaccharides, disaccharides, cyclitols (inositol)
been developed for the regioselective installation of benzyl and
and cis-1,2-diol containing alicyclic and cyclic systems with
good to excellent yields.
its variants.3,4 Among those, most commonly used are tin-
mediated5 and transition-metal (Ni, Cu, Hg) mediated6 as well
as through selective reductive opening of benzylidene ring.2b−e
RESULTS AND DISCUSSION
■
Most of these methods involve stoichiometric amount of
To start with, cis-1,2-diol containing manno-glycoside 1a and
benzyl bromide were selected as substrates and silver oxide
(Ag2O) as an additive. Silver oxide is well reported for the
catalysts and heating, which limits their compatibility with
many sensitive functional groups containing molecules. In the
past decade, catalytic-controlled regioselective methods were
developed, where diarylborinic acid4f and modified tin-based
conditions were employed.7 In further refinement, dimethyltin
dichloride has been used for regioselective acylation8a−c and
Received: February 4, 2015
© XXXX American Chemical Society
A
DOI: 10.1021/acs.joc.5b01898
J. Org. Chem. XXXX, XXX, XXX−XXX

The Journal of Organic Chemistry
Article
activation of alkyl bromide10 and hence selected in the present
case. In the first experiment, manno-glycoside 1a was treated
with benzyl bromide in the presence of dibutyltin oxide
(Bu2SnO) and additive silver oxide (Ag2O) at room temper-
ature, the 3-O-benzylated product 2a was formed in a very
minor (<10%) quantity (Table 1, entry a). The addition of base
Table 2. Regioselective Alkylation of cis-1,2-Diol Containing
Monosaccharides
d
Table 1. Optimization Studies
entry
catalyst
additive
base
2a yield (%)
a
a
b
c
d
e
f
Bu2SnO
Bu2SnO
Me2SnCl2
Me2SnCl2
Me2SnCl2
−
Ag2O
Ag2O
Ag2O
Ag2O
−
−
TEA
<10
a
<10
b
−
TEA
−
94
b
93
−
10
a
Ag2O
−
a
b
1
Yields were determined by H NMR. Isolated yields.
did not show any improvement (Table 1, entry b). Surprisingly,
when dimethyltin dichloride was used, corresponding benzy-
lated product 2a was observed in 94% yield (Table 1, entry c).
In the further refinement, the addition of base did not show any
improvement (Table 1, entry d). In the absence of Ag2O, no
product formation was observed (Table 1, entry e). In the
absence of dimethyltin dichloride, 2a was formed in a very low
yield (Table 1, entry f). The best conditions for the
regioselective alkylation of cis-1,2-diols involves dimethyltin
dichloride (10 mol %) as catalyst and Ag2O (1.1 equiv) as
additive at room temperature (Table 1, entry c).
With the optimized conditions in hand, the further
investigation was conducted with benzyl and its other variants
and cis-1,2-diol containing sugars (Table 2). When the reaction
with benzyl variants such as allyl (All) bromide, p-
methoxybenzyl (PMB) chloride and 2-naphthylmethyl (Nap)
bromide was tried, coupling underwent smoothly and furnished
corresponding 3-O-substitued products 2b, 2c and 2d in a yield
of 92, 97 and 95% respectively. Further, the suitability of
present optimized conditions toward the tolerance of base
sensitive functional groups such as silyl and benzoyl as well as
heat sensitive group such as azido has also been investigated. 6-
O-TBS-mannoglycoside 1b when reacted with benzyl and its
variants (allyl, PMB and naphthyl halides), regioselective
corresponding 3-O-substitued products 2e, 2f, 2g and 2h
were obtained in an excellent yield of 85, 81, 87 and 79%,
respectively. Similarly, 1,2-cis-diols containing sugar such as
rhamnoside 1c also reacted with benzyl, allyl, PMB and
naphthyl halides and gave 3-O-substituted products 2i, 2j, 2k
and 2l in a yields of 97, 96, 98 and 98%, respectively. The
benzoyl- and azido-substituted mannoglycosides 1d and 1e also
underwent alkylation and gave 3-O-substituted products 2m−s
in good to excellent yields (74−84%). Next, we studied the
differentially protected β-galactosides, where 3,4-dihydroxy-β-
glactoside 1f, when explored under optimized conditions, it also
reacted smoothly with benzyl, allyl and naphthyl halides and
gave corresponding 3-O-substituted products 2t, 2u and 2v in a
yield of 89, 91 and 92% respectively. 6-O-TBS protected β-
galactoside 1g also reacted smoothly with all the selected
halides and furnished respective 3-O-substituted products 2w,
a
b
Isolated yield. 1.0 equiv of BnBr and 2.0 equiv of Ag2O were
c
employed. 2.5 equiv of BnBr and 2.2 equiv of Ag2O were employed.
d
Reaction performed in 0.2−1.0 mmol scale.
2x, 2y and 2z in a yield of 84, 81, 78 and 89% respectively. The
sugar with free primary hydroxy group such as galactal 1h was
also investigated, which delivered a mixture of products.
Notably, when the same reaction was performed with 2.5
equiv of benzyl bromide, dibenzylated product 2a′ was
obtained in a yield of 80%. trans-1,2-Diol containing sugar 1i
when treated under optimized conditions, 3-O-benzyl galacto-
side 2b′ was formed with 42% yield along with an unseparable
2-O-benzyl substituted galactoside.
To further expand the scope of optimized conditions, we
investigated cis-1,2-diols containing disaccharides and non-
sugars such as cyclitols (inositol derivatives) and all the results
are summarized in Table 3. Under optimized conditions, the
disaccharide 3a underwent selective benzylation at O-3′ with
B
DOI: 10.1021/acs.joc.5b01898
J. Org. Chem. XXXX, XXX, XXX−XXX

The Journal of Organic Chemistry
Article
Table 3. Regioselective Alkylation of cis-1,2-Diol Containing
Disaccharide and Cyclitols
Table 4. Regioselective Alkylation of Alicyclic and Cyclic-
Diols
c
b
a
b
c
Isolated yield. Reaction carried out for 36 h. Reaction performed on
0.2−1.0 mmol scale.
a
b
Isolated yield. Reaction performed on 0.2−1.0 mmol scale.
62% of yield of product 4a. Cyclitol such as dihydroxy-L-myo-
inositol 5a when treated with benzyl, allyl, PMB and naphthyl
halides, corresponding 1-O-substitued products 6a, 6b, 6c and
6d were obtained in a yield of 94, 84, 88 and 87%, respectively.
Trihydroxy-L-myo-inositol 5b also worked successfully with
benzyl, allyl, PMB and naphthyl halides and furnished
regioselectively corresponding 1-O-substitued products 6e, 6f,
6g and 6h in a yield of 87, 90, 89 and 83%, respectively.
Similarly, 1,4-di-O-benzyl-myo-inositol 5c when tried, 5-O-
substituted products 6i, 6j, 6k and 6l were obtained in a yield of
60, 70, 66 and 64%, respectively.
In further exploration, cis-1,2-diol containing alicyclic and
cyclic systems were also investigated under optimized
conditions (Table 4). Alicyclic diol, propan-1,2-diol having
primary and secondary hydroxyl groups, underwent selectively
benzylation at primary hydroxyl and delivered 75% of 1-O-
benzyl-2-propanol 8a. Six, five and eight membered cyclo-
alkane-1,2-diols 9a, 9b and 9c were selectively monobenzylated
and furnished corresponding products 10a, 10b and 10c in an
excellent yield of 96, 91, 97% respectively. Furan-3,4-diol such
as 1,4-anhydroerythritol when attempted, provided regioselec-
tive monobenzylated product 10d in an excellent yield of 98%.
The literature precedents10−12 and the present results
suggested that the observed high regioselectivity could be
explained by the following facts: first, complexation of tin
catalyst increases the reactivity of hydroxy groups by increasing
their nucleophilicity;10 second, among the secondary alcohol, it
is well-known that the equatorial OH groups are comparatively
more reactive than axial partners and primary are more reactive
than secondary;11 third, activation of alkyl halide with silver12
makes it workable at room temperature.
nonsugars bearing cis-1,2-diol system using dimethyltin
dichloride as catalyst and silver oxide as an additive at room-
temperature. The operational simplicity and avoidance of high
temperature are the attractive features of the present method,
which finds applications in the preparation of complex
molecules.
EXPERIMENTAL SECTION
■
General Information. Freshly dried acetonitrile by standard
method of solvent purification was used for all reactions. NMR
measurements (1H, and 13C) were recorded in CDCl3 using 400/500
MHz spectrometer fitted with pulse-field gradient probe, and
tetramethylsilane (TMS) or residual resonance of deuterated solvent
were used as internal reference. Spectral features are tabulated in the
following order: chemical shift (δ, ppm); multiplicity (brs-broad
singlet, s-singlet, d-doublet, dd-double doublet, t-triplet, q-quartet, m-
complex multiplet); coupling constants (J, Hz); number of protons.
Mass spectra were recorded on MALDI-TOF/TOF mass spectropho-
tometer using 2,5-dihydroxy benzoic acid/α-cyano-4-hydroxy cinnamic
acid as matrix in acetonitrile:water containing 0.01% TFA. HRMS
were recorded on HRMS-6540-UHD machine. Optical rotations were
measured on a digital polarimeter. Analytical TLC was performed on
silica gel 60 F254 plates, and compounds were visualized by spraying
and charring with phosphomolybdic acid or 20% H2SO4 in MeOH as
developing reagent. Column chromatography was carried out with
flash silica gel (230−400 mesh).
General Procedure. The cis-1,2-diol substrate 1, 3, 5, 7, 9 (0.2 to
1.0 mmol, 1 equiv), dimethyltin dichloride (10 mol %) and Ag2O (1.1
equiv) were weighed into a 10 mL round-bottom flask and dissolved in
dry acetonitrile (2 to 7 mL see below). Alkyl halide (1.5 equiv) was
then added, the reaction flask was capped with a septum and purged
with nitrogen. The mixture was stirred vigorously for 24 h at room
temperature. The resulting mixture was diluted with CH2Cl2, filtered
through Celite and concentrated to dryness. The resulting crude
material was purified by chromatography on flash silica gel (230−400).
Methyl-4,6-O-benzylidene-3-O-benzyl-α-D-mannopyranoside
(2a).7a,13 Methyl-4,6-O-benzylidene-α-D-mannopyranoside 1a14 (100
CONCLUSION
In conclusion, we have developed a mild, general and catalytic
method for the regioselective alkylation of sugars and
■
C
DOI: 10.1021/acs.joc.5b01898
J. Org. Chem. XXXX, XXX, XXX−XXX

The Journal of Organic Chemistry
Article
mg, 0.354 mmol), benzyl bromide (63 μL, 0.532 mmol), dimethyltin
dichloride (7.7 mg, 10 mol %) and Ag2O (90.1 mg, 0.390 mmol) were
stirred in acetonitrile (3 mL) under nitrogen atmosphere at room
temperature for 24 h. Column chromatographic purification (hexane/
EtOAc, 80:20) afforded the title compound as a colorless oil (124.0
mg, 94%); Rf = 0.35 (hexane/EtOAc, 70:30); [α]D = +43.2 (c 0.1,
purification (hexane/EtOAc, 80:20) afforded the title compound as a
colorless oil (109 mg, 85%); Rf = 0.40 (hexane/EtOAc, 70:30); [α]D =
+34.6 (c 0.1, CHCl3); 1H NMR (400 MHz, CDCl3) δ 7.41−7.29 (m,
5H), 4.73 (s, 1H), 4.69 (d, J = 8.9 Hz, 2H), 3.97 (s, 1H), 3.89 (t, J =
7.3 Hz, 3H), 3.69 (dd, J = 9.0, 2.5 Hz, 1H), 3.60 (dd, J = 9.8, 2.1 Hz,
1H), 3.36 (s, 3H), 0.91 (s, 9H), 0.10 (s, 6H); 13C NMR (100 MHz,
CDCl3) δ 138.0, 128.6, 128.5, 128.0, 127.9, 127.5, 126.9, 100.4, 79.5,
72.1, 71.1, 68.8, 67.8, 65.1, 64.5, 54.8, 25.9, 18.3, −5.4; MALDI TOF
MS calcd for C20H34O6Si [M + Na]+ 421.2017, found 421.2021.
Methyl-6-O-(tert-butyldimethylsilyl)-3-O-allyl-α-D-mannopyrano-
side (2f). Methyl-6-O-(tert-butyldimethylsilyl)-α-D-mannopyranoside
1b (100 mg, 0.324 mmol), allyl bromide (42.0 μL, 0.487 mmol),
dimethyltin dichloride (7.1 mg, 10 mol %) and Ag2O (82.5 mg, 0.357
mmol) were stirred in acetonitrile (3 mL) under nitrogen atmosphere
at room temperature for 24 h. Chromatographic purification (hexane/
EtOAc, 80:20) afforded the title compound as a colorless oil (91 mg,
81%); Rf = 0.40 (hexane/EtOAc, 70:30); [α]D = +33.0 (c 0.1, CHCl3);
1H NMR (400 MHz, CDCl3) δ 5.99−5.90 (m, 1H), 5.31 (d, J = 17.2
1
CHCl3); H NMR (400 MHz, CDCl3) δ 7.56−7.52 (m, 2H), 7.48−
7.27 (m, 8H), 5.65 (s, 1H), 4.89 (d, J = 11.9 Hz, 1H), 4.78 (d, J = 15.2
Hz 1H), 4.73 (d, J = 2.4 Hz, 1H), 4.32 (dd, J = 9.2, 3.7 Hz, 1H), 4.17−
4.08 (m, 2H), 3.98−3.79 (m, 3H), 3.41 (s, 3H) 2.08 (s, 1H); 13C
NMR (101 MHz, CDCl3) δ 138.0, 137.6, 128.9, 128.5, 128.2, 127.9,
127.8, 126.1, 101.6, 101.1, 78.8, 75.6, 73.0, 69.9, 68.9, 63.2, 54.9;
HRMS-MALDI (m/z) calcd for C21H24O6 [M + Na]+ 395.1465, found
395.1463.
Methyl-4,6-O-benzylidene-3-O-allyl-α-D-mannopyranoside
(2b).6d,15 Methyl-4,6-O-benzylidene-α-D-mannopyranoside 1a (100
mg, 0.354 mmol), allyl bromide (46 μL, 0.532 mmol), dimethyltin
dichloride (7.7 mg, 10 mol %) and Ag2O (90.1 mg, 0.390 mmol) were
stirred in acetonitrile (3 mL) under nitrogen atmosphere at room
temperature for 24 h. Column chromatographic purification (hexane/
EtOAc, 80:20) afforded the title compound as a colorless oil (105.0
mg, 92%); Rf = 0.35 (hexane/EtOAc, 70:30); [α]D = +45.3 (c 0.1,
Hz, 1H), 5.21 (d, J = 10.3 Hz, 1H), 4.73 (s, 1H), 4.02−4.28 (m, J =
12.3 Hz, 2H), 3.96 (s, 1H), 3.92−3.77 (m, 3H), 3.64−3.54 (m, 2H),
3.36 (s, 3H), 0.89 (s, 9H), 0.08 (s, 6H); 13C NMR (101 MHz, CDCl3)
δ 134.5, 117.8, 100.4, 78.9, 70.8, 70.8, 68.9, 67.7, 64.7, 54.8, 25.8, 18.2,
−5.5; HRMS-MALDI (m/z) calcd for C16H32O6Si [M + Na]+
371.1860, found 371.1842.
1
CHCl3); H NMR (400 MHz, CDCl3) δ 7.52−7.49 (m, 2H), 7.47−
7.32 (m, 3H), 5.99−5.89 (m, 1H), 5.61 (s, 1H), 5.33 (dd, J = 17.2, 1.5
Hz, 1H), 5.22 (dd, J = 10.4, 1.2 Hz, 1H), 4.80 (d, J = 0.7 Hz, 1H),
4.41−4.27 (m, 2H), 4.27−4.16 (m, 1H), 4.06 (dd, J = 15.9, 6.3 Hz,
2H), 3.92−3.76 (m, 3H), 3.42 (s, 3H), 2.66 (s, 1H); 13C NMR (101
MHz, CDCl3) δ 137.5, 134.5, 128.9, 128.2, 126.1, 117.4, 101.6, 101.1,
78.8, 75.1, 71.9, 69.9, 68.9, 63.2, 55.0; HRMS-MALDI (m/z) calcd for
C17H22O6 [M + Na]+ 345.1309, found 345.1326.
Methyl-6-O-(tert-butyldimethylsilyl)-3-O-(p-methoxybenzyl)-α-D-
Mannopyranoside (2g). Methyl-6-O-(tert-butyldimethylsilyl)-α-D-
mannopyranoside 1b (100 mg, 0.324 mmol), p-methoxybenzyl
chloride (66.0 μL, 0.487 mmol), dimethyltin dichloride (7.1 mg, 10
mol %) and Ag2O (82.5 mg, 0.357 mmol) were stirred in acetonitrile
(3 mL) under nitrogen atmosphere at room temperature for 24 h.
Chromatographic purification (hexane/EtOAc, 80:20) afforded the
title compound as a colorless oil (120 mg, 87%); Rf = 0.38 (hexane/
Methyl-4,6-O-benzylidene-3-O-(p-methoxybenzyl)-α-D-manno-
pyranoside (2c).16 Methyl-4,6-O-benzylidene-α-D-mannopyranoside
1a (100 mg, 0.354 mmol), p-methoxybenzyl chloride (72 μL, 0.532
mmol), dimethyltin dichloride (7.7 mg, 10 mol %) and Ag2O (90.1
mg, 0.390 mmol) were stirred in acetonitrile (3 mL) under nitrogen
atmosphere at room temperature for 24 h. Column chromatographic
purification (hexane/EtOAc, 80:20) afforded the title compound as a
colorless oil (138.0 mg, 97%); Rf = 0.32 (hexane/EtOAc, 70:30); [α]D
1
EtOAc, 70:30); [α]D = +19.8 (c 0.1, CHCl3); H NMR (400 MHz,
CDCl3) δ 7.31 (d, J = 6.1 Hz, 2H), 6.90 (d, J = 8.1 Hz, 2H), 4.74 (s,
1H), 4.63 (d, J = 5.0 Hz, 2H), 3.95 (d, J = 1.3 Hz, 1H), 3.88 (d, J = 5.2
Hz, 3H), 3.80 (d, J = 12.2 Hz, 3H), 3.64 (dd, J = 8.6, 2.2 Hz, 1H), 3.60
(dd, J = 9.9, 5.1 Hz, 1H), 3.37 (s, 3H), 0.91 (s, 9H), 0.10 (s, 6H); 13C
NMR (100 MHz, CDCl3) δ 159.5, 130.1, 129.6, 128.6, 114.0, 100.4,
79.1, 71.7, 70.9, 68.9, 67.8, 64.6, 55.2, 54.8, 25.9, 18.3, −5.4; HRMS-
MALDI (m/z) calcd for C21H36O7Si [M + Na]+ 451.2123, found
451.2124.
1
= +41.2 (c 0.1, CHCl3); H NMR (400 MHz, CDCl3) δ 7.53−7.45
(m, 2H), 7.40−7.32 (m, 3H), 7.25 (d, J = 8.3 Hz, 2H), 6.85 (d, J = 8.0
Hz, 2H), 5.59 (s, 1H), 4.76 (d, J = 11.4 Hz, 1H), 4.69 (s, 1H), 4.61 (d,
J = 11.4 Hz, 1H), 4.32−4.22 (m, 1H), 4.07 (t, J = 9.2 Hz, 1H), 3.94 (d,
J = 1.9 Hz, 1H), 3.90−3.73 (m, 3H), 3.35 (s, 3H); 13C NMR (101
MHz, CDCl3) δ 159.4, 137.6, 130.1, 129.6, 128.9, 128.2, 126.1, 113.9,
101.6, 101.2, 78.9, 75.4, 72.8, 69.9, 68.9, 63.3, 55.3, 54.9; HRMS-
MALDI (m/z) calcd for C22H26O7 [M + Na]+ 425.1571, found
425.1598.
Methyl-6-O-(tert-butyldimethylsilyl)-3-O-(2-methylnaphthalen-
yl)-α-D-mannopyranoside (2h).4f Methyl-6-O-(tert-butyldimethylsil-
yl)-α-D-mannopyranoside 1b (100 mg, 0.324 mmol), 2-
(bromomethyl)naphthalene (107.5 mg, 0.487 mmol), dimethyltin
dichloride (7.1 mg, 10 mol %) and Ag2O (82.5 mg, 0.357 mmol) were
stirred in acetonitrile (3 mL) under nitrogen atmosphere at room
temperature for 24 h. Chromatographic purification (hexane/EtOAc,
80:20) afforded the title compound as a colorless oil (114 mg, 79%);
Methyl-4,6-O-benzylidene-3-O-(2-methylnaphthalenyl)-α-D-
mannopyranoside (2d). Methyl-4,6-O-benzylidene-α-D-mannopyra-
noside 1a (100 mg, 0.354 mmol), 2-(bromomethyl)naphthalene (117
mg, 0.532 mmol), dimethyltin dichloride (7.7 mg, 10 mol %) and
Ag2O (90.1 mg, 0.390 mmol) were stirred in acetonitrile (3 mL) under
nitrogen atmosphere at room temperature for 24 h. Column
chromatographic purification (hexane/EtOAc, 80:20) afforded the
title compound as a colorless oil (142.0 mg, 95%); Rf = 0.35 (hexane/
1
Rf = 0.40 (hexane/EtOAc, 70:30); [α]D = +31.9 (c 0.1, CHCl3); H
NMR (400 MHz, CDCl3) δ 7.82 (d, J = 12.2 Hz, 4H), 7.47 (dd, J =
11.5, 7.0 Hz, 3H), 4.85 (s, 2H), 4.72 (s, 1H), 3.99 (d, J = 1.3 Hz, 1H),
3.95−3.83 (m, 3H), 3.73 (dd, J = 8.9, 2.1 Hz, 1H), 3.64−3.54 (m,
1H), 3.34 (s, 3H), 0.90 (s, 9H), 0.09 (s, 6H); 13C NMR (101 MHz,
CDCl3) δ 135.4, 133.3, 133.1, 128.4, 127.9, 127.7, 126.8, 126.2, 126.1,
125.7, 100.4, 79.4, 72.2, 70.9, 69.2, 67.9, 64.7, 54.8, 25.9, 18.3, −5.4;
HRMS-MALDI (m/z) calcd for C24H36O6Si [M + Na]+ 471.2173,
found 471.2154.
1
EtOAc, 70:30); [α]D = +36.9 (c 0.1, CHCl3); H NMR (400 MHz,
CDCl3) δ 7.88−7.67 (m, 4H), 7.55−7.32 (m, 8H), 5.61 (s, 1H), 4.95
(d, J = 12.1 Hz, 1H), 4.87 (d, J = 13.0 Hz, 1H), 4.70 (s, 1H), 4.32−
4.22 (m, 1H), 4.12 (t, J = 9.3 Hz, 1H), 4.02 (d, J = 2.0 Hz, 1H), 3.99−
3.89 (m, 1H), 3.90−3.74 (m, 2H), 3.30 (s, 3H), 2.94 (brs, 1H); 13C
NMR (101 MHz, CDCl3) δ 137.6, 135.4, 133.3, 133.1, 129.0, 128.3,
128.0, 127.7, 126.6, 126.2, 126.0, 125.8, 101.7, 101.1, 78.8, 75.6, 72.9,
69.8, 68.9, 63.3, 54.9; HRMS-MALDI (m/z) calcd for C25H26O6 [M +
Na]+ 445.1622, found 445.1635.
Methyl-6-O-(tert-butyldimethylsilyl)-3-O-benzyl-α-D-
mannopyranoside(2e).4f Methyl-6-O-(tert-butyldimethylsilyl)-α-D-
mannopyranoside 1b17 (100 mg, 0.324 mmol), benzyl bromide (58
μL, 0.487 mmol), dimethyltin dichloride (7.1 mg, 10 mol %) and
Ag2O (82.5 mg, 0.357 mmol) were stirred in acetonitrile (3 mL) under
nitrogen atmosphere at room temperature for 24 h. Chromatographic
Methyl-3-O-benzyl-α-D-rhamnopyranoside (2i).4f Methyl-α-D-
rhamnopyranoside 1c18 (100 mg, 0.561 mmol), benzyl bromide
(102.0 μL, 0.843 mmol), dimethyltin dichloride (12.3 mg, 10 mol %)
and Ag2O (142.7 mg, 0.618 mmol) were stirred in acetonitrile (3 mL)
under nitrogen atmosphere at room temperature for 24 h. Column
chromatographic purification (hexane/EtOAc, 80:20) afforded the title
compound as a colorless oil (146.0 mg, 97%); Rf = 0.37 (hexane/
1
EtOAc, 70:30); [α]D = +15.8 (c 0.1, CHCl3); H NMR (400 MHz,
CDCl3) δ 7.39 (s, 5H), 4.73 (d, J = 8.8 Hz, 2H), 4.59 (d, J = 11.6 Hz,
1H), 4.03 (d, J = 0.9 Hz, 1H), 3.74−3.53 (m, 3H), 3.38 (s, 3H), 1.34
(d, J = 6.0 Hz, 3H); 13C NMR (101 MHz, CDCl3) δ 137.7, 128.7,
D
DOI: 10.1021/acs.joc.5b01898
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Article
128.2, 128.0, 100.4, 79.8, 71.7, 71.5, 67.8, 67.7, 54.8, 17.6; HRMS (m/
z) calcd for C14H21O5 [M + H]+ 269.1384, found 269.1375.
0.52 (hexane/EtOAc, 50:50); [α]D = +51.0 (c 0.1, CHCl3); 1H NMR
(500 MHz, CDCl3) δ 8.06 (d, J = 7.7 Hz, 2H), 7.56 (t, J = 7.3 Hz,
1H), 7.43 (t, J = 7.6 Hz, 2H), 6.0−5.9 (m, 1H), 5.33 (d, J = 17.1 Hz,
1H), 5.23 (d, J = 10.4 Hz, 1H), 4.81 (s, 1H), 4.68 (dd, J = 12.0, 4.6 Hz,
1H), 4.58 (d, J = 12.2 Hz, 1H), 4.20 (dd, J = 12.5, 5.6 Hz, 1H), 4.12
(dd, J = 12.5, 5.8 Hz, 1H), 4.03 (s, 1H), 3.92−3.82 (m, 2H), 3.63 (dd,
J = 8.2, 3.0 Hz, 1H), 3.40 (s, 3H), 2.95 (s, 1H), 2.53 (s, 1H); 13C
NMR (126 MHz, CDCl3) δ 167.0, 134.2, 133.4, 133.2, 129.9, 129.8,
128.4, 118.2, 100.5, 79.0, 70.9, 70.2, 67.8, 66.4, 64.1, 55.0; HRMS-
MALDI (m/z) calcd for C17H22O7 [M + Na]+ 361.1258, found
361.1275.
Methyl-6-O-benzoyl-3-O-(2-methylnaphthalenyl)-α-D-manno-
pyranoside (2o). Methyl-6-O-benzoyl-α-D-mannopyranoside 1d (100
mg, 0.336 mmol), 2-(bromomethyl)naphthalene (74 mg, 0.336
mmol), dimethyltin dichloride (7.3 mg, 10 mol %) and Ag2O (155.1
mg, 0.671 mmol) were stirred in acetonitrile (3 mL) under nitrogen
atmosphere at room temperature for 24 h. Column chromatographic
purification (hexane/EtOAc, 60:40) afforded the title compound as a
colorless syrup (102.6 mg, 70%); Rf = 0.52 (hexane/EtOAc, 50:50);
[α]D = +30.8 (c 0.1, CHCl3); 1H NMR (400 MHz, CDCl3) δ 8.05 (d,
J = 7.2 Hz, 2H), 7.85−7.81 (m, 4H), 7.54 (t, J = 7.4 Hz, 1H), 7.52−
7.34 (m, 5H), 4.87 (d, J = 11.7 Hz, 1H), 4.80 (d, J = 9.3 Hz, 2H), 4.68
(dd, J = 12.0, 4.6 Hz, 1H), 4.56 (d, J = 12.0 Hz, 1H), 4.06 (s, 1H),
3.97−3.81 (m, 2H), 3.76 (dd, J = 8.4, 2.8 Hz, 1H), 3.37 (s, 3H); 13C
NMR (126 MHz, CDCl3) δ 167.0, 135.1, 133.2, 133.2, 133.1, 129.8,
128.6, 128.4, 128.0, 127.8, 126.9, 126.4, 126.2, 125.7, 100.5, 79.4, 72.2,
70.9, 67.9, 66.5, 64.1, 55.0; HRMS-MALDI (m/z) calcd for C25H26O7
[M + Na]+ 461.1571, found 461.1585.
Methyl-6-azido-6-deoxy-3-O-benzyl-α-D-mannopyranoside (2p).
Methyl-6-azido-6-deoxy-α-D-mannopyranoside 1e20 (200 mg, 0.913
mmol), benzyl bromide (162 μL, 1.37 mmol), dimethyltin dichloride
(20 mg, 10 mol %) and Ag2O (232.1 mg, 1.00 mmol) were stirred in
acetonitrile (4 mL) under nitrogen atmosphere at room temperature
for 24 h. Column chromatographic purification (hexane/EtOAc,
80:20) afforded the title compound as a colorless syrup (240.7 mg,
85%); Rf = 0.55 (hexane/EtOAc, 70:30); [α]D = +5.6 (c 0.1, CHCl3);
1H NMR (400 MHz, CDCl3) δ 7.44−7.29 (m, 5H), 4.77 (d, J = 12.0
Hz, 1H), 4.64 (d, J = 11.3 Hz, 1H), 4.54 (d, J = 11.5 Hz, 1H), 3.99 (s,
1H), 3.80−3.67 (m, 2H), 3.62 (dd, J = 8.7, 3.1 Hz, 1H), 3.51−3.43
(m, 2H), 3.37 (d, J = 10.1 Hz, 3H), 2.64 (s, 2H); 13C NMR (126
MHz, CDCl3) δ 137.5, 128.8, 128.6, 128.4, 128.1, 100.4, 79.6, 71.8,
71.3, 67.5, 67.0, 55.1, 51.5; HRMS-MALDI (m/z) calcd for
C14H19N3O5 [M + Na]+ 332.1217, found 332.1212.
Methyl-6-azido-6-deoxy-3-O-allyl-α-D-mannopyranoside (2q).
Methyl-6-azido-6-deoxy-α-D-mannopyranoside 1e (200 mg, 0.913
mmol), allyl bromide (115 μL, 1.37 mmol), dimethyltin dichloride
(20 mg, 10 mol %) and Ag2O (232.1 mg, 1.00 mmol) were stirred in
acetonitrile (4 mL) under nitrogen atmosphere at room temperature
for 24 h. Column chromatographic purification (hexane/EtOAc,
80:20) afforded the title compound as a colorless syrup (215.2 mg,
91%); Rf = 0.48 (hexane/EtOAc, 70:30); [α]D = +26.6 (c 0.1, CHCl3);
1H NMR (500 MHz, CDCl3) δ 5.98−5.90 (m, 1H), 5.34 (dd, J = 17.2,
1.1 Hz, 1H), 5.26 (d, J = 10.3 Hz, 1H), 4.79 (s, 1H), 4.20 (dd, J = 12.5,
5.7 Hz, 1H), 4.11−4.04 (m, 1H), 4.02 (s, 1H), 3.82−3.72 (m, 2H),
3.57 (dd, J = 8.6, 3.0 Hz, 1H), 3.55−3.49 (m, 2H), 3.42 (s, 3H), 2.75
(s, 1H), 2.68 (s, 1H); 13C NMR (126 MHz, CDCl3) δ 134.0, 118.4,
100.4, 79.3, 71.2, 70.6, 67.5, 67.0, 55.2, 51.5; HRMS (m/z) calcd for
C10H18N3O5 [M + H]+ 260.1241, found 260.1249.
Methyl-6-azido-6-deoxy-3-O-(p-methoxybenzyl)-α-D-mannopyr-
anoside (2r). Methyl-6-azido-6-deoxy-α-D-mannopyranoside 1e (200
mg, 0.913 mmol), p-methoxybenzyl chloride (185 μL, 1.37 mmol),
dimethyltin dichloride (20 mg, 10 mol %) and Ag2O (232.1 mg, 1.00
mmol) were stirred in acetonitrile (4 mL) under nitrogen atmosphere
at room temperature for 24 h. Column chromatographic purification
(hexane/EtOAc, 80:20) afforded the title compound as a colorless
Methyl-3-O-allyl-α-D-rhamnopyranoside (2j). Methyl-α-D-rham-
nopyranoside 1c (100 mg, 0.561 mmol), allyl bromide (72.0 μL,
0.843 mmol), dimethyltin dichloride (12.3 mg, 10 mol %) and Ag2O
(142.7 mg, 0.618 mmol) were stirred in acetonitrile (3 mL) under
nitrogen atmosphere at room temperature for 24 h. Column
chromatographic purification (hexane/EtOAc, 80:20) afforded the
title compound as a colorless oil (117 mg, 96%); Rf = 0.55 (hexane/
1
EtOAc, 70:30); [α]D = +41.6 (c 0.1, CHCl3); H NMR (400 MHz,
CDCl3) δ 6.07−5.82 (m, 1H), 5.35 (d, J = 11.2 Hz, 1H), 5.24 (d, J =
10.1 Hz, 1H), 4.72 (s, 1H), 4.20 (dd, J = 12.5, 5.5 Hz, 1H), 4.08 (dd, J
= 11.9, 5.6 Hz, 1H), 4.01 (s, 1H), 3.73−3.61 (m, 1H), 3.56 (dd, J =
15.0, 5.6 Hz, 2H), 3.39 (s, 3H), 1.34 (d, J = 5.8 Hz, 3H); 13C NMR
(101 MHz, CDCl3) δ 134.3, 118.0, 100.4, 79.37, 71.3, 70.6, 67.8, 67.7,
54.8, 17.6; HRMS (m/z) calcd for C10H19O5 [M + H]+ 219.1227,
found 219.1231.
Methyl-3-O-(p-methoxybenzyl)-α-D-rhamnopyranoside (2k).19
Methyl-α-D-rhamnopyranoside 1c (100 mg, 0.561 mmol), p-
methyoxybenzyl chloride (111.3 μL, 0.843 mmol), dimethyltin
dichloride (12.3 mg, 10 mol %) and Ag2O (142.7 mg, 0.618 mmol)
were stirred in acetonitrile (3 mL) under nitrogen atmosphere at room
temperature for 24 h. Column chromatographic purification (hexane/
EtOAc, 80:20) afforded the title compound as a colorless oil (164.0
mg, 98%); Rf = 0.55 (hexane/EtOAc, 30:70); [α]D = +11.8 (c 0.1,
CHCl3); 1H NMR (400 MHz, CDCl3) δ 7.31 (d, J = 8.3 Hz, 2H), 6.92
(d, J = 8.3 Hz, 2H), 4.72 (s, 1H), 4.65 (d, J = 11.3 Hz, 1H), 4.53 (d, J
= 14.4 Hz, 1H), 4.01 (s, 1H), 3.81 (s, 3H), 3.70−3.59 (m, 2H), 3.54
(t, J = 9.2 Hz, 1H), 3.38 (s, 3H), 1.33 (d, J = 6.1 Hz, 3H); 13C NMR
(101 MHz, CDCl3) δ 159.6, 129.8, 129.6, 114.1, 100.4, 79.5, 71.5,
71.3, 67.7, 67.6, 55.3, 54.8, 17.6; HRMS m/z calcd for C15H23O6 [M +
H]+ 299.1489, found 299.1513.
Methyl-3-O-(2-methylnaphthalenyl)-α-D-rhamnopyranoside
(2l).4f Methyl-α-D-rhamnopyranoside 1c (100 mg, 0.561 mmol), 2-
(bromomethyl)naphthalene (186 mg, 0.843 mmol), dimethyltin
dichloride (12.3 mg, 10 mol %) and Ag2O (142.7 mg, 0.618 mmol)
were stirred in acetonitrile (3 mL) under nitrogen atmosphere at room
temperature for 24 h. Column chromatographic purification (hexane/
EtOAc, 80:20) afforded the title compound as a colorless oil (175.0
mg, 98%); Rf = 0.57 (hexane/EtOAc, 70:30); [α]D = +17.3 (c 0.1,
1
CHCl3); H NMR (400 MHz, CDCl3) δ 7.80−7.70 (m, 4H), 7.45−
7.37 (m, 3H), 4.76 (d, J = 11.7 Hz, 1H), 4.69−4.58 (m, 2H), 3.96 (s,
1H), 3.64−3.44 (m, 3H), 3.26 (s, 3H), 1.23 (d, J = 5.9 Hz, 3H); 13C
NMR (101 MHz, CDCl3) δ 135.1, 133.3, 133.1, 128.6, 127.9, 127.8,
126.9, 126.4, 126.2, 125.7, 100.4, 79.8, 71.8, 71.6, 67.8, 67.7, 54.8, 17.7;
HRMS (m/z) calcd for C18H23O5 [M + H]+ 319.1540, found
319.1561.
Methyl-6-O-benzoyl-3-O-benzyl-α-D-mannopyranoside (2m).
Methyl-6-O-benzoyl-α-D-mannopyranoside 1d (100 mg, 0.336
mmol), benzyl bromide (41 μL, 0.336 mmol), dimethyltin dichloride
(7.3 mg, 10 mol %) and Ag2O (155.1 mg, 0.671 mmol) were stirred in
acetonitrile (3 mL) under nitrogen atmosphere at room temperature
for 24 h. Column chromatographic purification (hexane/EtOAc,
60:40) afforded the title compound as a colorless oil (96.3 mg, 74%);
1
Rf = 0.52 (hexane/EtOAc, 50:50); [α]D = +26.8 (c 0.1, CHCl3); H
NMR (500 MHz, CDCl3) δ 8.13−8.01 (m, 2H), 7.53 (t, J = 10.6 Hz,
1H), 7.47−7.28 (m, 7H), 4.78 (s, 1H), 4.69 (d, J = 11.5 Hz, 1H),
4.67−4.60 (m, 2H), 4.57 (d, J = 12.1 Hz, 1H), 4.04−4.00 (m, 1H),
3.90−3.83 (m, 2H), 3.75−3.67 (m, 1H), 3.38 (s, 3H), 2.98 (brs, 1H),
2.66 (brs, 1H); 13C NMR (126 MHz, CDCl3) δ 167.0, 137.7, 133.2,
129.8, 128.7, 128.4, 128.2, 128.0, 100.5, 79.5, 72.1, 70.2, 67.8, 66.4,
64.2, 54.1; HRMS-MALDI (m/z) calcd for C21H24O7 [M + Na]+
411.1414, found 411.1429.
Methyl-6-O-benzoyl-3-O-Allyl-α-D-mannopyranoside (2n). Meth-
yl-6-O-benzoyl-α-D-mannopyranoside 1d (100 mg, 0.336 mmol), allyl
bromide (28 μL, 0.336 mmol), dimethyltin dichloride (7.3 mg, 10 mol
%) and Ag2O (155.1 mg, 0.671 mmol) were stirred in acetonitrile (3
mL) under nitrogen atmosphere at room temperature for 24 h.
Column chromatographic purification (hexane/EtOAc, 60:40) af-
forded the title compound as a colorless syrup (91.8 mg, 81%); Rf =
syrup (216.7 mg, 70%); Rf = 0.54 (hexane/EtOAc, 70:30); [α]D
=
1
+2.3 (c 0.1, CHCl3); H NMR (400 MHz, CDCl3) δ 7.28 (d, J = 8.7
Hz, 2H), 6.90 (d, J = 8.6 Hz, 2H), 4.76 (d, J = 1.1 Hz, 1H), 4.62 (d, J
= 11.3 Hz, 1H), 4.48 (d, J = 11.3 Hz, 1H), 3.98 (d, J = 1.2 Hz, 1H),
3.81 (s, 3H), 3.72 (t, J = 10.4 Hz, 2H), 3.61 (dd, J = 8.7, 3.0 Hz, 1H),
E
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3.54−3.44 (m, 2H), 3.40 (s, 3H), 2.57 (s, 1H), 2.49 (s, 1H); 13C NMR
(126 MHz, CDCl3) δ 159.6, 129.7, 129.5, 114.1, 100.4, 79.3, 71.4,
71.2, 67.5, 67.0, 55.3, 55.1, 51.5; HRMS-MALDI (m/z) calcd for
C15H21N3O6 [M + Na]+ 362.1323, found 362.1335.
77.1, 75.8, 73.8, 72.2, 69.5, 67.1; MALDI TOF MS calcd for
C37H36O5S [M + Na]+ 615.2176, found 615.2190.
Phenyl-6-O-(tert-butyldimethylsilyl)-3-O-benzyl-1-thio-β-D-galac-
topyranoside (2w).7b Phenyl-6-O-(tert-butyldimethylsilyl)-1-thio-β-D-
galactopyranoside 1g17 (120 mg, 0.311 mmol), benzyl bromide (55
μL, 0.466 mmol), dimethyltin dichloride (6.8 mg, 10 mol %) and
Ag2O (78.4 mg, 0.342 mmol) were stirred in acetonitrile (3 mL) under
nitrogen atmosphere at room temperature for 24 h. Column
chromatographic purification (hexane/EtOAc,70:30) afforded the
title compound as a colorless oil (124.3 mg, 84%); Rf = 0.35
(hexane/EtOAc, 70:30); [α]D = −32.0 (c 0.1, CHCl3); 1H NMR (400
MHz, CDCl3) δ 7.56 (d, J = 4.9 Hz, 2H), 7.46−7.19 (m, 8H), 4.82−
4.67 (m, 2H), 4.51 (d, J = 9.7 Hz, 1H), 4.07 (s, 1H), 3.99−3.74 (m,
3H), 3.53−3.34 (m, 2H), 2.62 (brs, 1H), 2.47 (brs, 1H), 0.90 (s, 9H),
0.09 (s, 3H), 0.08 (s, 3H); 13C NMR (101 MHz, CDCl3) δ 137.8,
132.5, 132.3, 128.9, 128.6, 128.1, 127.9, 127.8, 88.7, 81.7, 78.6, 72.1,
69.0, 66.6, 62.7, 25.9, 18.3, −5.3, −5.4; HRMS-MALDI (m/z) calcd
for C25H36O5Ssi [M + Na]+ 499.1945, found 499.1943.
Phenyl-6-O-(tert-butyldimethylsilyl)-3-O-allyl-1-thio-β-D-galacto-
pyranoside (2x). Phenyl-6-O-(tert-butyldimethylsilyl)-1-thio-β-D-gal-
actopyranoside 1g (120 mg, 0.311 mmol), allyl bromide (40 μL, 0.466
mmol), dimethyltin dichloride (6.8 mg, 10 mol %) and Ag2O (78.4
mg, 0.342 mmol) were stirred in acetonitrile (3 mL) under nitrogen
atmosphere at room temperature for 24 h. Column chromatographic
purification (hexane/EtOAc, 70:30) afforded the title compound as a
colorless oil (109.0 mg, 81%); Rf = 0.35 (hexane/EtOAc, 70:30); [α]D
= −3.3 (c 0.1, CHCl3); 1H NMR (400 MHz, CDCl3) δ 7.67−7.49 (m,
2H), 7.28 (t, J = 6.0 Hz, 3H), 6.03−5.90 (m, 1H), 5.32 (d, J = 16.1 Hz,
1H), 5.22 (d, J = 10.3 Hz, 1H), 4.53 (d, J = 9.7 Hz, 1H), 4.29−4.15
(m, 2H), 4.12 (d, J = 2.4 Hz, 1H), 3.96−3.86 (m, 2H), 3.79 (t, J = 9.3
Hz, 1H), 3.51 (t, J = 5.5 Hz, 1H), 3.39 (dd, J = 8.9, 2.9 Hz, 1H), 2.65
(brs, 1H), 2.48 (brs, 1H), 0.91 (s, 9H), 0.11 (s, 3H), 0.09 (s, 3H); 13C
NMR (101 MHz, CDCl3) δ 134.4, 132.4, 128.9, 127.8, 117.9, 88.7,
81.5, 78.5, 70.9, 68.7, 66.5, 62.8, 25.9, 18.3, −5.4, −5.5; HRMS-
MALDI (m/z) calcd for C21H34O5SSi [M + Na]+ 449.1788, found
449.1770.
Methyl-6-azido-6-deoxy-3-O-(2-methylnaphthalenyl)-α-D-man-
nopyranoside (2s). Methyl-6-azido-6-deoxy-α-D-mannopyranoside 1e
(200 mg, 0.913 mmol), 2-(bromomethyl)naphthalene (302 mg, 1.37
mmol), dimethyltin dichloride (20 mg, 10 mol %) and Ag2O (232.1
mg, 1.00 mmol) were stirred in acetonitrile (3 mL) under nitrogen
atmosphere at room temperature for 24 h. Column chromatographic
purification (hexane/EtOAc, 80:20) afforded the title compound as a
colorless syrup (278.0 mg, 84%); Rf = 0.55 (hexane/EtOAc, 70:30);
1
[α]D = +8.2 (c 0.1, CHCl3); H NMR (400 MHz, CDCl3) δ 7.85−
7.74 (m, 4H), 7.51−7.41 (m, 3H), 4.80 (d, J = 11.8 Hz, 1H), 4.74 (d, J
= 0.7 Hz, 1H), 4.66 (d, J = 11.7 Hz, 1H), 4.00 (d, J = 1.2 Hz, 1H), 3.78
(t, J = 9.4 Hz, 1H), 3.73−3.62 (m, 2H), 3.51−3.43 (m, 2H), 3.35 (s,
3H), 2.69 (brs, 2H); 13C NMR (126 MHz, CDCl3) δ 134.9, 133.2,
133.1, 128.7, 128.0, 127.8, 127.0, 126.5, 126.3, 125.6, 100.5, 79.6, 71.9,
71.3, 67.6, 67.1, 55.1, 51.5; HRMS-MALDI (m/z) calcd for
C18H21N3O5 [M + Na]+ 382.1373, found 382.1395.
Phenyl-2,3,6-tri-O-benzyl-1-thio-β-D-galactopyranoside (2t).21
Phenyl-2,6-di-O-benzyl-1-thio-β-D-galactopyranoside 1f22 (120 mg,
0.265 mmol), benzyl bromide (48 μL, 0.398 mmol), dimethyltin
dichloride (5.8 mg, 10 mol %) and Ag2O (67.4 mg, 0.292 mmol) were
stirred in acetonitrile (3 mL) under nitrogen atmosphere at room
temperature for 24 h. Column chromatographic purification (hexane/
EtOAc, 80:20) afforded the title compound as a colorless oil (128.0
mg, 89%); Rf = 0.35 (hexane/EtOAc, 70:30); [α]D = −4.0 (c 0.1,
1
CHCl3); H NMR (400 MHz, CDCl3) δ 7.40 (d, J = 5.4 Hz, 2H),
7.30−6.99 (m, 18H), 4.65 (d, J = 10.3 Hz, 1H), 4.57 (d, J = 10.1 Hz,
1H), 4.52 (d, J = 6.0 Hz, 1H), 4.47 (d, J = 11.0 Hz, 2H), 4.39 (s, 2H),
3.92 (d, J = 2.2 Hz, 1H), 3.67−3.55 (m, 3H), 3.46−3.35 (m, 2H); 13C
NMR (101 MHz, CDCl3) δ 138.2, 138.0, 137.7, 134.0, 131.8, 128.9,
128.6, 128.5, 128.4, 128.3, 128.1, 128.0, 127.9, 127.85, 127.82, 127.4,
87.8, 82.6, 77.1, 77.1, 75.8, 73.8, 72.2, 69.5, 67.0; HRMS-MALDI (m/
z) calcd for C33H34O5S [M + Na]+ 565.2019, found 565.2005.
Phenyl-3-O-allyl-2,6-di-O-benzyl-1-thio-β-D-galactopyranoside
(2u). Phenyl-2,6-di-O-benzyl-1-thio-β-D-galactopyranoside 1f (120 mg,
0.265 mmol), allyl bromide (33 μL, 0.398 mmol), dimethyltin
dichloride (5.8 mg, 10 mol %) and Ag2O (67.4 mg, 0.292 mmol) were
stirred in acetonitrile (3 mL) under nitrogen atmosphere at room
temperature for 24 h. Column chromatographic purification (hexane/
EtOAc, 70:30) afforded the title compound as a colorless oil (118.0
mg, 91%); Rf = 0.35 (hexane/EtOAc, 70:30); [α]D = −9.2 (c 0.1,
CHCl3); 1H NMR (400 MHz, CDCl3) δ 7.56−7.46 (m, 2H), 7.35 (d,
J = 7.3 Hz, 2H) 7.29−7.13 (m, 12H), 5.89−5.80 (m, 1H), 5.23 (d, J =
17.2 Hz, 1H), 5.12 (d, J = 10.4 Hz, 1H), 4.73 (d, J = 10.3 Hz, 1H),
4.65 (d, J = 10.2 Hz, 1H), 4.56 (d, J = 9.8 Hz, 1H), 4.50 (s, 2H), 4.16−
4.06 (m, 2H), 4.03 (d, J = 2.8 Hz, 1H), 3.77−3.67 (m, 2H), 3.63 (t, J =
9.4 Hz, 1H), 3.54 (t, J = 5.7 Hz, 1H), 3.41 (dd, J = 8.9, 3.0 Hz, 1H);
13C NMR (101 MHz, CDCl3) δ 138.2, 137.9, 134.4, 134.0, 131.8,
Phenyl-6-O-(tert-butyldimethylsilyl)-3-O-(p-methoxybenzyl)-1-
thio-β-D-galactopyranoside (2y). Phenyl-6-O-(tert-butyldimethylsil-
yl)-1-thio-β-D-galactopyranoside 1g (120 mg, 0.311 mmol), p-
methoxybenzyl chloride (61 μL, 0.466 mmol), dimethyltin dichloride
(6.8 mg, 10 mol %) and Ag2O (78.4 mg, 0.342 mmol) were stirred in
acetonitrile (3 mL) under nitrogen atmosphere at room temperature
for 24 h. Column chromatographic purification (hexane/EtOAc,
70:30) afforded the title compound as a colorless oil (122.0 mg, 78%);
1
Rf = 0.35 (hexane/EtOAc, 70:30); [α]D = −11.0 (c 0.1, CHCl3); H
NMR (400 MHz, CDCl3) δ 7.61−7.49 (m, 2H), 7.36−7.21 (m, 5H),
6.86 (t, J = 12.5 Hz, 2H), 4.74−4.61 (m, 2H), 4.52 (d, J = 8.7 Hz, 1H),
4.06 (d, J = 2.4 Hz, 1H), 3.94−3.85 (m, 2H), 3.84−3.76 (m, 4H), 3.47
(t, J = 5.6 Hz, 1H), 3.41 (dd, J = 8.9, 2.9 Hz, 1H), 2.61 (brs, 1H), 2.46
(brs, 1H), 0.90 (s, 9H), 0.08 (s, 3H), 0.07 (s, 3H); 13C NMR (101
MHz, CDCl3) δ 159.5, 132.3, 129.8, 129.6, 128.9, 127.8, 114.0, 88.8,
81.4, 78.6, 71.7, 68.8, 66.6, 62.6, 55.3, 25.9, 18.3, −5.4, −5.5; HRMS-
MALDI (m/z) calcd for C26H38O6SSi [M + Na]+ 529.2015, found
529.2015.
129.0, 128.4, 128.39, 128.3, 127.8, 127.8, 127.4, 117.7, 87.7, 82.4, 77.0,
75.8, 73.8, 71.2, 69.5, 67.1; HRMS-MALDI (m/z) calcd for C29H32O5S
[M + Na]+ 515.1863, found 515.1877.
Phenyl-6-O-(tert-butyldimethylsilyl)-3-O-(2-methylnaphthalen-
yl)-1-thio-β-D-galactopyranoside (2z). Phenyl-6-O-(tert-butyldime-
thylsilyl)-1-thio-β-D-galactopyranoside 1g (120 mg, 0.311 mmol), 2-
(bromomethyl)naphthalene (103 mg, 0.466 mmol), dimethyltin
dichloride (6.8 mg, 10 mol %) and Ag2O (78.4 mg, 0.342 mmol)
were stirred in acetonitrile (3 mL) under nitrogen atmosphere at room
temperature for 24 h. Column chromatographic purification (hexane/
EtOAc, 70:30) afforded the title compound as a colorless oil (145.0
mg, 89%); Rf = 0.35 (hexane/EtOAc, 70:30); [α]D = −32.0 (c 0.1,
Phenyl-3-O-(2-methylnaphthalenyl)-2,6-di-O-benzyl-1-thio-β-D-
galactopyranoside (2v). Phenyl-2,6-di-O-benzyl-1-thio-β-D-galacto-
pyranoside 1f (120 mg, 0.265 mmol), 2-(bromomethyl)naphthalene
(88 mg, 0.398 mmol), dimethyltin dichloride (5.8 mg, 10 mol %) and
Ag2O (67.4 mg, 0.292 mmol) were stirred in acetonitrile (3 mL) under
nitrogen atmosphere at room temperature for 24 h. Column
chromatographic purification (hexane/EtOAc, 70:30) afforded the
title compound as a colorless oil (144.6 mg, 92%); Rf = 0.36 (hexane/
1
EtOAc, 70:30); [α]D = +7.6 (c 0.1, CHCl3); H NMR (400 MHz,
1
CHCl3); H NMR (400 MHz, CDCl3) δ 7.86−7.78 (m, 4H), 7.55−
CDCl3) δ 7.95−7.75 (m, 4H), 7.62 (dd, J = 5.0, 1.8 Hz, 2H), 7.55−
7.43 (m, 5H), 7.40−7.23 (m, 11H), 4.98−4.79 (m, 4H), 4.69 (d, J =
9.7 Hz, 1H), 4.60 (s, 2H), 4.18 (s, 1H), 3.83 (t, J = 4.9 Hz, 3H), 3.72−
3.58 (m, 2H), 2.67 (s, 1H); 13C NMR (101 MHz, CDCl3) δ 138.3,
138.0, 135.1, 134.0, 133.3, 133.1, 131.8, 128.9, 128.5, 128.4, 128.3,
127.9, 127.9, 127.8, 127.7, 127.4, 126.8, 126.3, 126.1, 125.8, 87.8, 82.5,
7.46 (m, 5H), 7.28 (d, J = 5.2 Hz, 3H), 4.97−4.87 (m, 2H), 4.50 (d, J
= 9.6 Hz, 1H), 4.10 (s, 1H), 3.92−3.82 (m, 3H), 3.51−3.42 (m, 2H),
0.88 (s, 9H), 0.07 (s, 3H), 0.06 (s, 3H); 13C NMR (101 MHz, CDCl3)
δ 135.2 133.2, 133.1, 132.5, 132.4, 128.9, 128.5, 127.9, 127.8, 127.8,
126.9, 126.3, 126.1, 125.7, 88.7, 81.6, 78.5, 72.2, 69.0, 66.8, 62.7, 25.9,
F
DOI: 10.1021/acs.joc.5b01898
J. Org. Chem. XXXX, XXX, XXX−XXX

The Journal of Organic Chemistry
Article
18.3, −5.4, −5.5; HRMS-MALDI (m/z) calcd for C29H38O5SSi [M +
Na]+ 549.2101, found 549.2105.
Column chromatographic purification (hexane/EtOAc, 70:30) af-
forded the title compound as a colorless oil (181.7 mg, 84%); [α]D =
+15.0 (c 0.1, CHCl3); 1H NMR (400 MHz, CDCl3) δ 7.36−7.12 (m,
15H), 5.99−5.77 (m, 2H), 5.31−5.16 (m, 2H), 5.15−5.03 (m, 2H),
4.85−4.72 (m, 4H), 4.64 (d, J = 12.1 Hz, 2H), 4.32−4.18 (m, 2H),
4.15−4.08 (m, 3H), 3.87 (t, J = 9.5 Hz, 1H), 3.72 (t, J = 9.5 Hz, 1H),
3.36−3.28 (m, 2H), 3.16 (dd, J = 9.6, 2.7 Hz, 1H), 2.38 (brs, 1H); 13C
NMR (101 MHz, CDCl3) δ 138.8, 138.0, 135.3, 134.7, 129.8, 129.0,
128.5, 128.3, 128.0, 127.9, 127.8, 127.6, 117.3, 116.6, 83.1, 81.1, 80.8,
79.9, 79.4, 75.9, 74.6, 72.8, 71.9, 67.8; HRMS-MALDI (m/z) calcd for
C33H38O6 [M + Na]+ 553.2561, found 553.2565.
6-O-Allyl-3,4,5-tri-O-benzyl-1-O-(p-methoxybenzyl)-L-myo-inosi-
tol (6c).25 6-O-Allyl-3,4,5-tri-O-benzyl-L-myo-inositol 5a (200 mg,
0.408 mmol), p-methoxybenzyl chloride (83 μL, 0.612 mmol),
dimethyltin dichloride (8.9 mg, 10 mol %) and Ag2O (103 mg,
0.379 mmol) were stirred in acetonitrile (3 mL) under nitrogen
atmosphere at room temperature for 24 h. Column chromatographic
purification (hexane/EtOAc, 70:30) afforded the title compound as a
colorless oil (219.6 mg, 88%); Rf = 0.32 (hexane/EtOAc, 70:30); [α]D
= +8.6 (c 0.1, CHCl3); 1H NMR (400 MHz, CDCl3) δ 7.41−7.27 (m,
17H), 6.92 (d, J = 8.3 Hz, 2H), 6.08−5.95 (m, 1H), 5.37−5.28 (m,
1H), 5.20 (d, J = 10.3 Hz, 1H), 4.94−4.82 (m, 4H), 4.77−4.59 (m,
4H), 4.39 (qd, J = 12.1, 5.8 Hz, 2H), 4.19 (s, 1H), 3.98 (t, J = 9.5 Hz,
1H), 3.97−3.84 (m, 4H), 3.41 (dd, J = 16.9, 8.2 Hz, 2H), 3.36−3.27
(m, 1H); 13C NMR (101 MHz, CDCl3) δ 159.4, 138.9, 138.8, 138.0,
135.41, 130.2, 129.5, 128.5, 128.3, 128.0, 127.9, 127.8, 127.6, 127.5,
116.5, 113.9, 83.2, 81.1, 80.9, 79.8, 79.3, 76.0, 75.9, 74.7, 72.7, 72.5,
67.7, 55.3; HRMS-MALDI (m/z) calcd for C38H42O7 [M + Na]+
633.2823, found 633.2824.
3,6-Di-O-(benzyl)-D-galactal (2a′).4f D-Galactal (45 mg, 0.308
mmol), benzyl bromide 1h (76 μL, 0.647 mmol), dimethyltin
dichloride (6.7 mg, 10 mol %) and Ag2O (149.0 mg, 0.647 mmol)
were stirred in acetonitrile (3 mL) under nitrogen atmosphere at room
temperature for 24 h. Column chromatographic purification (hexane/
EtOAc, 90:10) afforded the title compound as a colorless oil (80.4 mg,
1
80%); [α]D = +10.5 (c 0.1, CHCl3); H NMR (500 MHz, CDCl3) δ
7.36−7.25 (m, 10H), 6.42 (d, J = 4.8 Hz, 1H), 4.79 (d, J = 5.2 Hz,
1H), 4.63−4.54 (m, 4H), 4.20−4.16 (m, 1H), 4.07 (d, J = 4.1 Hz,
1H), 4.00 (t, J = 6.1 Hz, 1H), 3.81−3.74 (m, 2H); 13C NMR (126
MHz, CDCl3) δ 144.1, 136.7, 136.6, 127.5, 127.4, 127.0, 126.9, 126.8,
98.4, 74.3, 72.6, 69.6, 69.4, 68.2, 61.9; HRMS-MALDI (m/z) calcd for
C20H22O4 [M + Na]+ 349.1410, found 349.1431.
Phenyl-4,6-O-benzylidene-3-O-benzyl-1-thio-β-D-galactopyrano-
side (2b′).6a,23 Phenyl-4,6-O-benzylidene-1-thio-β-D-galactopyranoside
1i24 (100 mg, 0.277 mmol), benzyl bromide (50 μL, 0.417 mmol),
dimethyltin dichloride (6.0 mg, 10 mol %) and Ag2O (70 mg, 0.306
mmol) were stirred in acetonitrile (3 mL) under nitrogen atmosphere
at room temperature for 24 h. Column chromatographic purification
(hexane/EtOAc, 70:30) afforded the title compound as a colorless oil
(51.7 mg, 42%); Rf = 0.32 (hexane/EtOAc, 70:30); Rf = 0.32 (hexane/
1
EtOAc, 30:70); [α]D = +15.6 (c 0.1, CHCl3); H NMR (400 MHz,
CDCl3) δ 7.60 (d, J = 7.3 Hz, 2H), 7.38−7.09 (m, 13H), 5.35 (s, 1H),
4.71−4.58 (m, 2H), 4.44 (d, J = 9.4 Hz, 1H), 4.27 (d, J = 12.3 Hz,
1H), 4.06 (d, J = 2.1 Hz, 1H), 3.90−3.84 (m, 2H), 3.43 (dd, J = 9.1,
2.7 Hz, 1H), 3.36 (s, 1H); 13C NMR (101 MHz, CDCl3) δ 138.0,
137.9, 133.7, 129.1, 128.9, 128.5, 128.1, 128.0, 127.9, 126.5, 101.1,
87.1, 80.3, 73.3, 71.7, 70.1, 69.4, 67.2; HRMS-MALDI (m/z) calcd for
C26H26O5S [M + Na]+ 473.1393, found 473.1376.
6-O-Allyl-3,4,5-tri-O-benzyl-1-O-(2-methylnaphthalenyl)-L-myo-
inositol (6d). 6-O-Allyl-3,4,5-tri-O-benzyl-L-myo-inositol 5a (200 mg,
0.408 mmol), 2-(bromomethyl)naphthalene (135 mg, 0.612 mmol),
dimethyltin dichloride (8.9 mg, 10 mol %) and Ag2O (103 mg, 0.379
mmol) were stirred in acetonitrile (3 mL) under nitrogen atmosphere
at room temperature for 24 h. Column chromatographic purification
(hexane/EtOAc, 70:30) afforded the title compound as a colorless oil
(223.7 mg, 87%); Rf = 0.32 (hexane/EtOAc, 70:30); [α]D = +2.5 (c
Phenyl-6,6′-di-O-(tert-butyldimethylsilyl)-3′-O-benzyl-1-S-β-D-
lactoside (4a). Phenyl-6,6′-di-O-(tert-butyldimethylsilyl)-1-S-α-D-Lac-
toside 3a (200 mg, 0.301 mmol), benzyl bromide (55 μL, 0.452
mmol), dimethyltin dichloride (6.6 mg, 10 mol %) and Ag2O (76.6
mg, 0.332 mmol) were stirred in acetonitrile (3 mL) under nitrogen
atmosphere at room temperature for 24 h. Column chromatographic
purification (hexane/EtOAc, 70:30) afforded the title compound as a
1
0.1, CHCl3); H NMR (400 MHz, CDCl3) δ 7.88−7.74 (m, 4H),
1
colorless oil (140.8 mg, 62%); [α]D = +4.3 (c 0.1, CHCl3); H NMR
7.54−7.43 (m, 3H), 7.29 (dd, J = 21.2, 13.8 Hz, 15 H), 6.07−5.98 (m,
1H), 5.30 (d, J = 18.0 Hz, 1H), 5.18 (d, J = 10.3 Hz, 1H), 4.89−4.81
(m, 6H), 4.68 (s, 2H), 4.43 (dd, J = 12.1, 5.6 Hz, 1H), 4.36 (dd, J =
12.2, 5.6 Hz, 1H), 4.19 (s, 1H), 3.95 (t, J = 9.5 Hz, 1H), 3.88 (t, J =
9.5 Hz, 1H), 3.45−3.33 (m, 3H), 2.51 (s, 1H); 13C NMR (101 MHz,
CDCl3) δ 138.8, 138.7, 137.9, 135.5, 1354, 133.3, 133.1, 128.4, 128.3,
128.3, 128.0, 127.9, 127.9, 127.8, 127.7, 127.6, 127.5, 126.6, 126.2,
126.0, 125.8, 116.6, 83.2, 81.1, 81.0, 79.8, 79.5, 76.0, 75.9, 74.6, 72.9,
72.7, 67.8; HRMS-MALDI (m/z) calcd for C41H42O6 [M + Na]+
653.2874, found 653.2865.
(500 MHz, CDCl3) δ 7.58 (d, J = 4.1 Hz, 2H), 7.43−7.26 (m, 8H),
4.76 (s, 2H), 4.52 (d, J = 9.7 Hz, 1H), 4.34 (d, J = 7.8 Hz, 1H), 4.04−
3.91 (m, 3H), 3.91−3.78 (m, 3H), 3.66 (t, J = 8.7 Hz, 1H), 3.56 (t, J =
9.2 Hz, 1H), 3.52−3.46 (m, 1H), 3.45−3.31 (m, 3H), 2.95 (brs, 1H),
2.67 (brs, 1H), 2.57 (brs, 1H), 0.93 (s, 9H), 0.89 (s, 9H), 0.12 (s, 3H),
0.11 (s, 3H), 0.07 (s, 6H); 13C NMR (126 MHz, CDCl3) δ 137.7,
133.1, 131.9, 128.8, 128.6, 128.1, 128.0, 127.9, 103.9, 87.1, 80.5, 80.2,
78.9, 76.2, 75.1, 72.2, 71.6, 70.7, 65.9, 62.6, 61.6, 25.9, 25.9, 18.3, 18.3,
−5.1, −5.2, −5.4, −5.4; HRMS-MALDI (m/z) calcd for
C37H60O10SSi2 [M + Na]+ 775.3338, found 775.3337.
1,3,4,5-Tetra-O-benzyl-L-myo-inositol (6e). 3,4,5-Tri-O-benzyl-L-
myo-inositol 5b26 (100 mg, 0.222 mmol), benzyl bromide (39 μL,
0.333 mmol), dimethyltin dichloride (4.8 mg, 10 mol %) and Ag2O
(56 mg, 0.244 mmol) were stirred in acetonitrile (3 mL) under
nitrogen atmosphere at room temperature for 24 h. Column
chromatographic purification (hexane/EtOAc, 70:30) afforded the
title compound as a colorless oil (104.4 mg, 87%); Rf = 0.58 (hexane/
6-O-Allyl-1,3,4,5-tetra-O-benzyl-L-myo-inositol (6a). 6-O-Allyl-
3,4,5-tri-O-benzyl-L-myo-inositol 5a25 (200 mg, 0.408 mmol), benzyl
bromide (72 μL, 0.612 mmol), dimethyltin dichloride (8.9 mg, 10 mol
%) and Ag2O (103 mg, 0.449 mmol) were stirred in acetonitrile (3
mL) under nitrogen atmosphere at room temperature for 24 h.
Column chromatographic purification (hexane/EtOAc, 70:30) af-
forded the title compound as a colorless oil (222.5 mg, 94%); [α]D =
1
EtOAc, 50:50); [α]D = +8.2 (c 0.1, CHCl3); H NMR (500 MHz,
1
+9.0 (c 0.1, CHCl3); H NMR (400 MHz, CDCl3) δ 7.42−7.24 (m,
CDCl3) δ 7.51−7.30 (m, 20H), 4.98 (dd, J = 10.6, 3.7 Hz, 2H), 4.95−
4.86 (m, 2H), 4.82−4.70 (m, 4H), 4.28 (s, 1H), 4.15 (t, J = 9.3 Hz,
1H), 4.05 (t, J = 9.2 Hz, 1H), 3.47 (d, J = 9.5 Hz, 1H), 3.40 (dd, J =
23.8, 14.8 Hz, 1H), 3.30 (d, J = 9.5 Hz, 1H), 2.59 (brs, 2H); 13C NMR
(126 MHz, CDCl3) δ 138.7, 138.0, 137.8, 128.7, 128.6, 128.5, 128.5,
128.1, 128.02, 127.99, 127.9, 127.7, 82.9, 80.9, 80.0, 79.2, 75.9, 75.5,
72.7, 72.5, 72.4, 67.1; HRMS-MALDI (m/z) calcd for C34H36O6 [M +
Na]+ 563.2404, found 563.2407.
1-O-Allyl-3,4,5-tri-O-benzyl-L-myo-inositol (6f). 3,4,5-Tri-O-ben-
zyl-L-myo-inositol 5b (100 mg, 0.222 mmol), allyl bromide (29 μL,
0.333 mmol), dimethyltin dichloride (4.8 mg, 10 mol %) and Ag2O
(56 mg, 0.244 mmol) were stirred in acetonitrile (3 mL) under
nitrogen atmosphere at room temperature for 24 h. Column
chromatographic purification (hexane/EtOAc, 70:30) afforded the
20H), 6.03−5.93 (m, 1H), 5.27 (dd, J = 17.2, 1.4 Hz, 1H), 5.15 (d, J =
10.4 Hz, 1H), 4.91−4.80 (m, 4H), 4.70 (d, J = 5.7 Hz, 4H), 4.36 (qd, J
= 12.2, 5.7 Hz, 2H), 4.19 (s, 1H), 3.95 (t, J = 9.5 Hz, 1H), 3.85 (t, J =
9.5 Hz, 1H), 3.44−3.28 (m, 3H); 13C NMR (101 MHz, CDCl3) δ
138.8, 138.7, 138.1, 138.0, 135.3, 128.5, 128.4, 128.0, 127.9, 127.8,
127.6, 127.5, 116.6, 83.2, 81.1, 80.9, 79.8, 79.6, 76.0, 75.9, 74.6, 72.8,
72.7, 67.7; MALDI TOF MS calcd for C37H40O6 [M + Na]+ 603.2717,
found 603.2714.
1,6-Di-O-allyl-3,4,5-tri-O-benzyl-L-myo-inositol (6b). 6-O-Allyl-
3,4,5-tri-O-benzyl-L-myo-inositol 5a (200 mg, 0.408 mmol), allyl
bromide (53 μL, 0.612 mmol), dimethyltin dichloride (8.9 mg, 10
mol %) and Ag2O (103 mg, 0.379 mmol) were stirred in acetonitrile
(3 mL) under nitrogen atmosphere at room temperature for 24 h.
G
DOI: 10.1021/acs.joc.5b01898
J. Org. Chem. XXXX, XXX, XXX−XXX

The Journal of Organic Chemistry
Article
title compound as a colorless oil (98.0 mg, 90%); Rf = 0.58 (hexane/
EtOAc, 50:50); [α]D = +11.4 (c 0.1, CHCl3); H NMR (500 MHz,
(brs, 2H), 2.55 (brs, 1H); 13C NMR (126 MHz, CDCl3) δ 138.6,
137.7, 134.5, 128.6, 128.5, 128.1, 128.1, 128.0, 127.8, 117.7, 80.3, 79.6,
79.1, 75.5, 74.1, 72.3, 71.9, 71.6, 67.01; HRMS-MALDI (m/z) calcd
for C23H28O6 [M + Na]+ 423.1778, found 423.1748.
1
CDCl3) δ 7.51−7.26 (m, 15H), 5.99−5.91 (m, 1H), 5.31 (d, J = 17.2
Hz, 1H), 5.21 (t, J = 13.8 Hz, 1H), 4.95−4.84 (m, 4H), 4.81−4.70 (m,
2H), 4.33−4.19 (m, 2H), 4.18−4.10 (m, 1H), 4.10−3.90 (m, 2H),
3.46 (d, J = 9.5 Hz, 1H), 3.38 (t, J = 9.2 Hz, 1H), 3.19 (d, J = 9.5 Hz,
1H), 2.49 (brs, 1H); 13C NMR (126 MHz, CDCl3) δ 138.7, 137.9,
134.5, 128.5, 128.5, 128.4, 128.1, 127.9, 127.8, 127.7, 118.0, 82.9, 81.0,
80.0, 78.9, 75.9, 75.5, 72.8, 72.2, 71.3, 66.9; HRMS-MALDI (m/z)
calcd for C30H34O6 [M + Na]+ 513.2448, found 513.2453.
1-O-(p-Methoxybenzyl)-3,6-di-O-benzyl-D/L-myo-inositol (6k).
3,6-Di-O-benzyl-D/L-myo-inositol 5c (80 mg, 0.222 mmol), p-
methoxybenzyl chloride (45 μL, 0.333 mmol), dimethyltin dichloride
(4.8 mg, 10 mol %) and Ag2O (56 mg, 0.244 mmol) were stirred in
acetonitrile (3 mL) under nitrogen atmosphere at room temperature
for 36 h. Column chromatographic purification (hexane/EtOAc,
60:40) afforded the title compound as a colorless oil (70.4 mg, 66%);
1-O-(p-Methoxybenzyl)-3,4,5-tri-O-benzyl-L-myo-inositol (6g).
3,4,5-Tri-O-benzyl-L-myo-inositol 5b (100 mg, 0.222 mmol), p-
methoxybenzyl chloride (45 μL, 0.333 mmol), dimethyltin dichloride
(4.8 mg, 10 mol %) and Ag2O (56 mg, 0.244 mmol) were stirred in
acetonitrile (3 mL) under nitrogen atmosphere at room temperature
for 24 h. Column chromatographic purification (hexane/EtOAc,
70:30) afforded the title compound as a colorless oil (112.7 mg, 89%);
1
Rf = 0.29 (hexane/EtOAc, 50:50); H NMR (400 MHz, CDCl3) δ
7.29−7.17 (m, 12H), 6.79 (d, J = 8.5 Hz, 2H), 4.87 (d, J = 11.2 Hz,
1H), 4.72−4.52 (m, 5H), 4.13 (s, 1H), 3.88 (t, J = 9.4 Hz, 1H), 3.76−
3.70 (m, 4H), 3.32 (t, J = 9.8 Hz, 2H), 3.15 (dd, J = 9.5, 2.2 Hz, 1H),
2.38 (brs, 1H); 13C NMR (126 MHz, CDCl3) δ 159.4, 138.7, 137.7,
129.8, 129.6, 128.6, 128.5, 128.1, 128.0, 127.8, 113.9, 80.4, 79.4, 79.0,
75.5, 74.2, 72.2, 72.1, 71.9, 66.9, 55.3; HRMS-MALDI (m/z) calcd for
C28H32O7 [M + Na]+ 503.2040, found 503.2061.
1
Rf = 0.56 (hexane/EtOAc, 50:50); [α]D = +9.4 (c 0.1, CHCl3); H
NMR (500 MHz, CDCl3) δ 7.44−7.23 (m, 17H), 6.90 (d, J = 4.8 Hz,
2H), 4.97−4.80 (m, 4H), 4.80−4.58 (m, 4H), 4.23 (s, 1H), 4.06 (t, J =
12.5 Hz, 1H), 3.98 (t, J = 9.4 Hz, 1H), 3.81 (s, 3H), 3.42 (d, J = 9.6
Hz, 1H), 3.35 (dd, J = 12.4, 6.2 Hz, 1H), 3.22 (d, J = 9.5 Hz, 1H); 13C
NMR (126 MHz, CDCl3) δ 159.5, 138.7, 137.9, 129.8, 129.6, 128.5,
128.5, 128.4, 128.1, 128.0, 127.8, 127.7, 114.0, 82.9, 80.9, 80.0, 78.7,
75.9, 75.5, 72.7, 72.4, 72.0, 67.0, 55.3; HRMS-MALDI (m/z) calcd for
C35H38O7 [M + Na]+ 593.2510, found 593.2512.
1-O-(2-Methylnaphthalenyl)-3,6-di-O-benzyl-D/L-myo-inositol
(6l). 3,6-Di-O-benzyl-D/L-myo-inositol 5c (80 mg, 0.222 mmol), p-
methoxybenzyl chloride (73 mg, 0.333 mmol), dimethyltin dichloride
(4.8 mg, 10 mol %) and Ag2O (56 mg, 0.244 mmol) were stirred in
acetonitrile (3 mL) under nitrogen atmosphere at room temperature
for 36 h. Column chromatographic purification (hexane/EtOAc,
60:40) afforded the title compound as a colorless syrup (71.1 mg,
64%); Rf = 0.29 (hexane/EtOAc, 50:50); 1H NMR (500 MHz,
CDCl3) δ 7.88−7.73 (m, 4H), 7.49−7.44 (m, 3H), 7.39−7.26 (m,
10H), 4.98 (d, J = 11.2 Hz, 1H), 4.88−4.78 (m, 3H), 4.65 (dd, J =
32.1, 11.7 Hz, 2H), 4.22 (s, 1H), 3.96 (t, J = 9.4 Hz, 1H), 3.85 (t, J =
9.4 Hz, 1H), 3.41 (dd, J = 16.9, 8.1 Hz, 2H), 3.19 (d, J = 7.8 Hz, 1H),
2.88 (brs, 2H), 2.62 (brs, 1H); 13C NMR (126 MHz, CDCl3) δ 138.7,
137.6, 135.2, 133.2, 133.1, 128.6, 128.5, 128.4, 128.1, 128.0, 127.9,
127.9, 127.8, 127.7, 126.8, 126.3, 126.1, 125.9, 80.5, 79.6, 79.0, 75.6,
74.2, 72.6, 72.3, 72.0, 67.0; MALDI TOF MS calcd for C31H32O6 [M +
Na]+ 523.2091, found 523.2093.
1-O-(2-Methylnaphthalenyl)-3,4,5-tri-O-benzyl-L-myo-inositol
(6h). 3,4,5-Tri-O-benzyl-L-myo-inositol 5b (100 mg, 0.222 mmol), 2-
(bromomethyl)naphthalene (74 mg, 0.333 mmol), dimethyltin
dichloride (4.8 mg, 10 mol %) and Ag2O (56 mg, 0.244 mmol)
were stirred in acetonitrile (3 mL) under nitrogen atmosphere at room
temperature for 24 h. Column chromatographic purification (hexane/
EtOAc, 70:30) afforded the title compound as a colorless oil (108.8
mg, 83%); Rf = 0.58 (hexane/EtOAc, 50:50); [α]D = +1.3 (c 0.1,
1
CHCl3); H NMR (500 MHz, CDCl3) δ 7.76 (t, J = 7.1 Hz, 3H),
7.44−7.39 (m, 3H), 7.27−7.16 (m, 16H), 4.86−4.72 (m, 6H), 4.61 (s,
2H), 4.16 (s, 1H), 4.03 (t, J = 9.4 Hz, 1H), 3.90 (t, J = 9.3 Hz, 1H),
3.31 (d, J = 8.9 Hz, 1H), 3.26 (t, J = 9.3 Hz, 1H), 3.20 (d, J = 9.2 Hz,
1H); 13C NMR (126 MHz, CDCl3) δ 138.7, 137.8, 135.2, 133.2,
133.1, 128.5, 128.4, 128.0, 127.9, 127.9, 127.8, 127.7, 126.8, 126.3,
126.2, 125.8, 82.9, 80.9, 79.9, 78.9, 75.9, 75.5, 72.7, 72.5, 72.5, 67.2;
HRMS-MALDI (m/z) calcd for C38H38O6 [M + Na]+ 613.2551, found
613.2556.
1-O-Benzyl-2-propanol (8a).4i Propane-1,2-diol 7a (30 mg, 0.39
mmol), benzyl bromide (70 μL, 0.59 mmol), dimethyltin dichloride
(8.6 mg, 10 mol %) and Ag2O (100.3 mg, 0.43 mmol) were stirred in
acetonitrile (3 mL) under nitrogen atmosphere at room temperature
for 24 h. Column chromatographic purification (hexane/EtOAc,
90:10) afforded the title compound as a colorless oil (118.0 mg, 75%);
1
Rf = 0.35 (hexane/EtOAc, 90:10); H NMR (500 MHz, CDCl3) δ
1,3,6-Tri-O-benzyl-D/L-myo-inositol (6i). 3,6-Di-O-benzyl-D/L-myo-
inositol 5c27 (80 mg, 0.222 mmol), benzyl bromide (41 μL, 0.333
mmol), dimethyltin dichloride (4.8 mg, 10 mol %) and Ag2O (56 mg,
0.244 mmol) were stirred in acetonitrile (3 mL) under nitrogen
atmosphere at room temperature for 36 h. Column chromatographic
purification (hexane/EtOAc, 60:40) afforded the title compound as a
7.44−7.20 (m, 5H), 4.62−4.46 (m, 2H), 4.03−3.87 (m, 1H), 3.49−
3.38 (m, 1H), 3.29−3.17 (m, 1H), 1.09 (dd, J = 16.4, 6.3 Hz, 3H); 13C
NMR (126 MHz, CDCl3) δ 138.0, 128.5, 127.8, 127.8, 75.8, 73.3, 66.5,
18.6; HRMS (m/z) calcd for C10H13O2 [M-H]− 165.0921, found
165.0922.
cis-2-(Benzyloxy)cyclohexanol (10a).4i cis-1,2-Cyclohexandiol 9a
(30 mg, 0.26 mmol), benzyl bromide (46 μL, 0.39 mmol), dimethyltin
dichloride (5.6 mg, 10 mol %) and Ag2O (65.1 mg, 0.28 mmol) were
stirred in acetonitrile (3 mL) under nitrogen atmosphere at room
temperature for 24 h. Column chromatographic purification (hexane/
EtOAc, 80:20) afforded the title compound as a colorless oil (51.1 mg,
96%); Rf = 0.65 (hexane/EtOAc, 80:20); 1H NMR (400 MHz,
CDCl3) δ 7.35−7.15 (m, 5H), 4.55 (d, J = 11.8 Hz, 1H), 4.44 (d, J =
11.8 Hz, 1H), 3.83−3.75 (m, 1H), 3.48−3.39 (m, 1H), 1.80−1.70 (m,
2H), 1.60−1.40 (m, 4H), 1.29−1.14 (m, 2H); 13C NMR (126 MHz,
CDCl3) δ 138.6, 128.5, 127.7, 127.6, 78.2, 70.2, 68.8, 30.4, 26.5, 22.1,
21.2; HRMS (m/z) calcd for C13H19O2 [M + H]+ 207.1380, found
207.1386.
1
colorless oil (60.0 mg, 60%); Rf = 0.29 (hexane/EtOAc, 50:50); H
NMR (400 MHz, CDCl3) δ 7.45−7.28 (m, 15H), 4.97 (d, J = 11.2 Hz,
1H), 4.81 (d, J = 11.2 Hz, 1H), 4.75−4.66 (m, 4H), 4.25 (t, J = 2.4 Hz,
1H), 3.99 (t, J = 9.4 Hz, 1H), 3.85 (t, J = 9.4 Hz, 1H), 3.49−3.39 (m,
2H), 3.24 (dd, J = 9.5, 2.5 Hz, 1H), 2.74 (s, 3H); 13C NMR (126
MHz, CDCl3) δ 138.7, 137.8, 137.7, 128.6, 128.5, 128.5, 128.1, 128.0,
127.97, 127.94, 127.78, 80.5, 79.7, 79.0, 75.5, 74.3, 72.5, 72.3, 71.9,
67.0; HRMS-MALDI (m/z) calcd for C27H30O6 [M + Na]+ 473.1935,
found 473.1952.
1-O-Allyl-3,6-di-O-benzyl-D/L-myo-inositol (6j). 3,6-Di-O-benzyl-
D/L-myo-inositol 5c (80 mg, 0.222 mmol), allyl bromide (28 μL,
0.333 mmol), dimethyltin dichloride (4.8 mg, 10 mol %) and Ag2O
(56 mg, 0.244 mmol) were stirred in acetonitrile (3 mL) under
nitrogen atmosphere at room temperature for 36 h. Column
chromatographic purification (hexane/EtOAc, 60:40) afforded the
title compound as a colorless oil (62.2 mg, 70%); Rf = 0.29 (hexane/
EtOAc, 50:50); 1H NMR (400 MHz, CDCl3) δ 7.37−7.28 (m, 10H),
5.96−5.87 (m, 1H), 5.29 (d, J = 17.2 Hz, 1H), 5.19 (d, J = 10.4 Hz,
1H), 4.93 (d, J = 11.2 Hz, 1H), 4.71 (dd, J = 23.8, 11.5 Hz, 3H), 4.24
(s, 1H), 4.22−4.08 (m, 2H), 3.95 (t, J = 9.4 Hz, 1H), 3.77 (t, J = 9.4
Hz, 1H), 3.40 (t, J = 9.3 Hz, 1H), 3.31−3.24 (m, 2.2 Hz, 2H), 2.84
cis-2-(Benzyloxy)cyclopentanol (10b).4i cis-1,2-Cyclopentanediol
9b (30 mg, 0.29 mmol), benzyl bromide (52 μL, 0.44 mmol),
dimethyltin dichloride (6.4 mg, 10 mol %) and Ag2O (74.1 mg, 0.32
mmol) were stirred in acetonitrile (3 mL) under nitrogen atmosphere
at room temperature for 24 h. Column chromatographic purification
(hexane/EtOAc, 80:20) afforded the title compound as a colorless oil
1
(51.3 mg, 91%); Rf = 0.60 (hexane/EtOAc, 80:20); H NMR (500
MHz, CDCl3) δ 7.42−7.32 (m, 5H), 4.62 (d, J = 11.8 Hz, 1H), 4.55
(d, J = 11.8 Hz, 1H), 4.13−4.09 (m, 1H), 3.89−3.79 (m, 1H), 2.53 (s,
H
DOI: 10.1021/acs.joc.5b01898
J. Org. Chem. XXXX, XXX, XXX−XXX

The Journal of Organic Chemistry
Article
1H), 1.91−1.72 (m, 5H), 1.55−1.46 (m, 1H); 13C NMR (126 MHz,
CDCl3) δ 138.2, 128.5, 127.8, 127.7, 81.4, 72.2, 71.57, 31.1, 27.9, 19.7;
HRMS (m/z) calcd for C12H17O2 [M + H]+ 193.1223, found
193.1228.
(3) (a) Liptak
́
, A.; Borbas
́
, A.; Bajza, I. In Comprehensive Glycoscience;
Kamerling, H., Ed.; Elsevier: Oxford, 2007; pp 203−259. (b) Lee, D.;
Taylor, M. S. Synthesis 2012, 44, 3421−3431.
(4) (a) Griswold, K. S.; Miller, S. J. Tetrahedron 2003, 59, 8869−
8875. (b) Kawabata, T.; Muramatsu, W.; Nishio, T.; Shibata, T.;
Schedel. J. Am. Chem. Soc. 2007, 129, 12890−12895. (c) Kawabata, T.;
Furuta, T. Chem. Lett. 2009, 38, 640−647. (d) Caregg, P. J. Pure Appl.
Chem. 1984, 56, 845. (e) Gouliaras, C.; Lee, D.; Chan, L.; Taylor, M.
S. J. Am. Chem. Soc. 2011, 133, 13926−13929. (f) Chan, L.; Taylor, M.
S. Org. Lett. 2011, 13, 3090−3093. (g) Lee, D.; Taylor, M. S. J. Am.
Chem. Soc. 2011, 133, 3724−3727. (h) Lee, D.; Taylor, M. S. Org.
Biomol. Chem. 2013, 11, 5409−5412. (i) Lee, D.; Williamson, C. L.;
Chan, L.; Taylor, M. S. J. Am. Chem. Soc. 2012, 134, 8260−8267.
(j) Sun, X.; Lee, H.; Lee, S.; Tan, K. L. Nat. Chem. 2013, 5, 790−795.
(5) (a) David, S.; Hanessian, S. Tetrahedron 1985, 41, 643−663.
(b) Ogawa, T.; Matsui, M. Carbohydr. Res. 1977, 56, C1−C6.
(6) (a) Gangadharmath, U. B.; Demchenko, A. V. Synlett 2004, 12,
2191−2193. (b) Osborn, H. M. I.; Brome, V. A.; Harwood, L. M.;
Suthers, W. G. Carbohydr. Res. 2001, 332, 157−166. (c) Maki, T.;
Ushijima, N.; Matsumura, Y.; Onomura, O. Tetrahedron Lett. 2009, 50,
1466−1468. (d) Eby, R.; Webster, K. T.; Schuerch, C. Carbohydr. Res.
1984, 129, 111−120. (e) Eby, R.; Schuerch, C. Carbohydr. Res. 1982,
100, C41−C43.
cis-2-(Benzyloxy)cyclooctanol (10c).4i cis-1,2-Cyclooctanediol 9c
(30 mg, 0.21 mmol), benzyl bromide (37 μL, 0.31 mmol), dimethyltin
dichloride (4.6 mg, 10 mol %) and Ag2O (52.5 mg, 0.23 mmol) were
stirred in acetonitrile (3 mL) under nitrogen atmosphere at room
temperature for 24 h. Column chromatographic purification (hexane/
EtOAc, 80:20) afforded the title compound as a colorless oil (47.2 mg,
97%); Rf = 0.69 (hexane/EtOAc, 80:20); 1H NMR (500 MHz,
CDCl3) δ 7.42−7.21 (m, 5H), 4.63 (d, J = 11.8 Hz, 1H), 4.52 (d, J =
11.7 Hz, 1H), 3.98−3.92 (m, 1H), 3.70−3.52 (m, 1H), 2.07−1.91 (m,
1H), 1.90−1.33 (m, 11H); 13C NMR (126 MHz, CDCl3) δ 138.5,
128.4, 127.7, 127.6, 80.9, 71.5, 70.8, 29.4, 26.8, 26.6, 25.5, 25.5, 22.5;
HRMS (m/z) calcd for C15H23O2 [M + H]+ 235.1693, found
235.1693.
(3R,4S)-4-(Benzyloxy)tetrahydrofuran-3-ol (10d). (3R,4S)-Tetra-
hydrofurandiol 9d (30 mg, 0.29 mmol), benzyl bromide 51 μL, 0.43
mmol), dimethyltin dichloride (6.4 mg, 10 mol %) and Ag2O (74.1
mg, 0.32 mmol) were stirred in acetonitrile (3 mL) under nitrogen
atmosphere at room temperature for 24 h. Column chromatographic
purification (hexane/EtOAc, 80:20) afforded the title compound as a
1
colorless oil (10.1 mg, 98%); Rf = 0.50 (hexane/EtOAc, 80:20); H
(7) (a) Giordano, M.; Iadonisi, A. J. Org. Chem. 2014, 79, 213−222.
(b) Xu, H.; Lu, Y.; Zhou, Y.; Ren, B.; Pei, Y.; Dong, H.; Pei, Z. Adv.
Synth. Catal. 2014, 356, 1735−1740.
NMR (400 MHz, CDCl3) δ 7.34−7.21 (m, 5H), 4.53 (s, 2H), 4.21−
4.16 (m, 1H), 4.02−3.95 (m, 1H), 3.85−3.78 (m, 2H), 3.74−3.64 (m,
2H), 2.86 (s, 1H); 13C NMR (126 MHz, CDCl3) δ 137.2, 128.6,
128.2, 127.9, 78.3, 73.4, 72.6, 70.4, 70.0; HRMS (m/z) calcd for
C11H15O3 [M + H]+ 195.1016, found 195.1015.
(8) (a) Demizu, Y.; Kubo, Y.; Miyoshi, H.; Maki, T.; Matsumura, Y.;
Moriyama, N.; Onomura, O. Org. Lett. 2008, 10, 5075−5077.
(b) Maki, T.; Iwasaki, F.; Matsumura, Y. Tetrahedron Lett. 1998, 39,
5601−5604. (c) Iwasaki, F.; Maki, T.; Onomura, O.; Nakashima, W.;
Matsumura, Y. J. Org. Chem. 2000, 65, 996−1002. (d) Muramatsu, W.;
Yoshimatsu, H. Adv. Synth. Catal. 2013, 355, 2518−2524.
(9) Dara, S.; Saikam, V.; Yadav, M.; Singh, P. P.; Vishwakarma, R. A.
Carbohydr. Res. 2014, 391, 93−96.
ASSOCIATED CONTENT
* Supporting Information
■
S
The Supporting Information is available free of charge on the
ACS Publications website at DOI: 10.1021/acs.joc.5b01898.
1
Copies of H and 13C NMR. (PDF)
(10) Melean, L. G.; Love, K. R.; Seeberger, P. H. Carbohydr. Res.
2002, 337, 1893−1916.
(11) Smiataczowa, K.; Kosmalski, J.; Widernik, T.; Warnke, Z.
Carbohydr. Res. 2003, 338, 969−975.
AUTHOR INFORMATION
Corresponding Authors
■
(12) Haines, A. H. In Advances in Carbohydrate Chemistry and
Biochemistry; Tipson, R. S., Derek, H., Eds.; Academic Press: Waltham,
MA, 1976; Vol. 33, pp 11−109.
*E-mail: ram@iiim.res.in. Tel.: +91-191-2569111. Fax: +91-
191-2569333.
(13) Polak
Leino, R. Eur. J. Org. Chem. 2009, 2009, 870−888.
(14) Ekholm, F. S.; Arda, A.; Eklund, P.; Andre,
Jimenez-Barbero, J.; Leino, R. Chem. - Eur. J. 2012, 18, 14392−14405.
́ ́
ova, M.; Roslund, M. U.; Ekholm, F. S.; Saloranta, T.;
*E-mail: ppsingh@iiim.ac.in.
Notes
The authors declare no competing financial interest.
́
́
S.; Gabius, H.-J.;
́
(15) Zhao, W.; Kong, F. Bioorg. Med. Chem. 2005, 13, 121−130.
(16) Cherif, S.; Clavel, J.-M.; Monneret, C. J. Carbohydr. Chem. 1998,
17, 1203−1218.
ACKNOWLEDGMENTS
■
The financial support by CSIR research grant # BSC 0108 is
gratefully acknowledged. VS, SD, and MY thank CSIR for
research fellowships. Authors are thankful for the support from
Instrumentation Division of CSIR-IIIM. IIIM Communication
No. is IIIM/1758/2015.
(17) Belaissaoui, A.; Saez, I. M.; Cowling, S. J.; Zeng, X.; Goodby, J.
W. Chem. - Eur. J. 2012, 18, 2366−2373.
(18) Zunk, M.; Kiefel, M. J. Tetrahedron Lett. 2011, 52, 1296−1299.
(19) Banaszek, A.; Zaitsev, V. Tetrahedron: Asymmetry 2004, 15,
299−306.
(20) Marchesan, S.; Macmillan, D. Chem. Commun. 2008, 36, 4321−
4323.
(21) Faltin, F.; Fehring, V.; Miethchen, R. Synthesis 2002, 2002,
REFERENCES
■
(1) (a) Bertram O., Fraser-Reid, K. T., Thiem, J., Eds.; Glycoscience
Chemistry and Chemical Biology; Springer-Verlag: Berlin, 2008.
(b) Seeberger, P. H.; Werz, D. B. Nature 2007, 446, 1046−51.
(c) Boltje, T. J.; Buskas, T.; Boons, G.-J. Nat. Chem. 2009, 1, 611−622.
(2) (a) Wang, C.-C.; Lee, J.-C.; Luo, S.-Y.; Kulkarni, S. S.; Huang, Y.-
W.; Lee, C.-C.; Chang, K.-L.; Hung, S.-C. Nature 2007, 446, 896−899.
1851−1856.
(22) Janczuk, A. J.; Zhang, W.; Andreana, P. R.; Warrick, J.; Wang, P.
G. Carbohydr. Res. 2002, 337, 1247−1259.
̀
(23) Fernandez-Mayoralas, A.; Marra, A.; Trumtel, M.; Veyrieres, A.;
Sinay, P. Carbohydr. Res. 1989, 188, 81−95.
̈
(24) Tatina, M.; Yousuf, S. K.; Mukherjee, D. Org. Biomol. Chem.
2012, 10, 5357−5360.
(b) Franca̧ is, A.; Urban, D.; Beau, J.-M. Angew. Chem., Int. Ed. 2007,
46, 8662−8665. (c) Wang, C.-C.; Kulkarni, S. S.; Lee, J.-C.; Luo, S.-Y.;
Hung, S.-C. Nat. Protoc. 2008, 3, 97−113. (d) Tran, A.-T.; Jones, R.
A.; Pastor, J.; Boisson, J.; Smith, N.; Galan, M. C. Adv. Synth. Catal.
2011, 353, 2593−2598. (e) Patil, P. S.; Lee, C.-C.; Huang, Y.-W.;
Zulueta, M. M. L.; Hung, S.-C. Org. Biomol. Chem. 2013, 11, 2605−
2612.
(25) Saikam, V.; Raghupathy, R.; Yadav, M.; Gannedi, V.; Singh, P.
P.; Qazi, N. A.; Sawant, S. D.; Vishwakarma, R. A. Tetrahedron Lett.
2011, 52, 4277−4279.
(26) Chung, S.-K.; Yu, S.-H.; Chang, Y.-T. J. J. Carbohydr. Chem.
1998, 17, 385−390.
I
DOI: 10.1021/acs.joc.5b01898
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Article
(27) Sudo, A.; Sano, T.; Harada, M.; Ishida, D. ACS Macro Lett.
2014, 3, 808−812.
J
DOI: 10.1021/acs.joc.5b01898
J. Org. Chem. XXXX, XXX, XXX−XXX