Regioselective benzoylation of 6-O-protected and 4,6-O-diprotected hexopyranosides as promoted by chiral and achiral ditertiary 1,2-diamines

Article abstract of DOI:10.1002/hlca.200290018

Monobenzoylation of triols (6-O-silylated glycopyranosides) or diols (4,6-O-benzylidenated glycopyranosides) with benzoyl chloride and triethylamine at - 60° to 23° is promoted by catalytic amounts of ditertiary 1,2-diamines. The regioselectivity depends

Full text of DOI:10.1002/hlca.200290018

Helvetica Chimica Acta Vol. 86 (2003)
4369
Regioselective Benzoylation of 6-O-Protected and 4,6-O-Diprotected
Hexopyranosides as Promoted by Chiral and Achiral Ditertiary 1,2-Diamines
by Guixian Hu and Andrea Vasella*
Laboratorium f¸r Organische Chemie, ETH-Hˆnggerberg, HCI, CH-8093Z¸rich
Dieter Seebach mit allen guten W¸nschen herzlich zugeeignet
Monobenzoylation of triols (6-O-silylated glycopyranosides) or diols (4,6-O-benzylidenated glycopyrano-
sides) with benzoyl chloride and triethylamine at À608 to 238 is promoted by catalytic amounts of ditertiary 1,2-
diamines. The regioselectivity depends mostly on the structure of the alcohols; it is modulated by the
configuration and constitution of the diamines, as shown by comparing the effect of Oriyama×s catalyst
((S)-1 and (R)-1), N,N,N',N'-tetramethylethylenediamine (TMEDA), N,N,N',N'-tetraethylethylenediamine
(TEEDA), Et3N, and EtNMe2. The effect of the catalysts on the reactivity is impaired by their steric hindrance.
In agreement with the modest enantioselectivity of the mono- and dibenzoylation of rac-cyclohexane-1,2-diol in
the presence of Oriyama×s catalyst, the influence of these diamines on the regioselectivity is rather limited.
While associated with procedural simplicity, these catalysts lead, in a few cases, to higher yields of a single
benzoate than established methods, viz. in the preparation of the 3-O-benzoyl b-d-glucopyranoside 4, the 2-O-
benzoyl a-d-galactopyranoside 22, the 3-O-benzoyl a-d-galactopyranoside 23, and the benzylidenated 2-O-
benzoyl a-d-galactopyranoside 44. The regioselective benzoylation of the benzylidenated b-d-mannopyrano-
side 47, leading to 48, appears to be new.
Introduction. The selective transformation of OH groups of carbohydrates is a
fundamental, but often not trivial preparative problem [1][2]. Primary and secondary
OH groups are usually readily differentiated. Regioselective transformations of
secondary OH groups can, however, be difficult, and even the selective introduction of
a protecting group may not be straightforward [3]. Regioselective O-acylation is one of
the most important methods to protect secondary OH groups (for some leading
references, see [4]). Like other regioselective transformations, it is based directly or
indirectly on intrinsic reactivity differences and requires appropriate reagents [5 7],
catalysts1), or prior OH group activation2). To which extent can this regioselectivity be
influenced by enantiomerically pure catalysts and promoters?
Enantioselective O-acylation of alcohols3) has been realized by nonenzymatic
kinetic resolution [19] of secondary alcohols and by nonenzymatic desymmetrisation
[20] of meso-diols. Nucleophilic catalysis of enantioselective O-acyl transfer [17] has
been developed intensively since Vedejs et al. reported the use of phosphines [21] and of
4-(dimethylamino)pyridine (DMAP) derivatives [22][23]. Enantiomerically pure
derivatives of DMAP and of 4-(pyrrolidino)pyridine have also been reported by the
1
)
)
)
For the use of enzymes, see [8][9]; for other catalysts, see [8][10], and references quoted there.
Usually by stannylation [11][12]. For reviews, see [11][13][14].
For reviews of enzymatic kinetic resolution and desymmetrisation, see [15]; for reviews of nonenzymatic
kinetic resolution and desymmetrisation, see [16 18].
2
3

4370
Helvetica Chimica Acta Vol. 86 (2003)
groups of Fu4) [24][25], Fuji [28], and Spivey [29], while Miller et al. used peptides as
enantioselective O-acyl transfer catalysts [30]. Oriyama et al. have shown that (S)-
proline-derived diamines are useful catalysts for the kinetic resolution of racemic
secondary alcohols and for the desymmetrisation of meso-diols [31 34]. Most relevant
to the question posed above are two papers by Kagan reporting the transformation of a
racemate or of a single enantiomer to regioisomeric products by using an asymmetric
reagent or catalyst [35].
We wondered about the use of enantiomerically pure catalysts for the regioselective
O-acylation of carbohydrates, and specifically about the extent to which Oriyama×s
catalysts (S)-1 and (R)-1 decrease or increase (and perhaps overcome) reactivity
differences between constitutionally different secondary OH groups. We planned to
first study the regioselectivity of the benzoylation of methyl 6-O-(tert-butyldiphenyl-
silyl)-b-d-glucopyranoside (2) and then of other methyl or allyl a-d- and b-d-
hexopyranosides protected by a 6-O-TBDPS or by a 4,6-O-benzylidene group.
Results and Discussion. Methyl 6-O-(tert-butyldiphenylsilyl)-b-d-glucopyrano-
side (2) [36] was benzoylated at À608 with benzoyl chloride (BzCl)/triethylamine
(Et3N) in dichloromethane (CH2Cl2) and in the presence, or absence, of 1 or 5 mol-%
of enantiomerically pure (S)-1 [31] or (R)-1 (Scheme 1 and Table 1). The addition of 4-
ä molecular sieves increased the rate of consumption of starting material [31]. These
conditions led to mixtures of the regioisomeric monobenzoates 3, 4, and 5, the
dibenzoates 6 and 7, and the tribenzoate 8 [36]. The dependence of the yields of these
benzoates on the presence of (S)-1, the temperature, and the duration of the reaction
shows a strong effect of (S)-1, resulting in a highly regioselective formation of the 3-O-
benzoate 4 that was isolated in yields of up to 84%. The benzoate 4 is the major product
even in the absence of (S)-1. It was isolated in a yield of 62.5%, when the benzoylation
was performed at 08 for 24 h; at À608, the yield dropped to 19.5%. Adding 1 mol-% of
(S)-1 and increasing the amount of BzCl and Et3N from 1 to 1.2 equiv. shortened the
reaction time from 24 h to 1 h at À608, providing 73% of 4. Performing the
benzoylation in the presence of 5 mol-% of (S)-1 yielded 4 in 78.5% at 08 and in 84% at
À608, while the analogous benzoylation at 238 (1 equiv. each of BzCl and Et3N) gave 4
in only 47% yield. Lowering the temperature to À608 raised the yield to 82.5%5). In
the presence of (R)-1 but under otherwise identical conditions, we isolated 62% of the
3-benzoate 4 and 13.5% of 4-benzoate 5. The isomer 5 was not observed when 2 was
benzoylated with 1 equiv. BzCl/Et3N in the presence of (S)-1, while increasing amounts
were formed in the presence of excess BzCl/Et3N and (S)-1 (4%), in the absence of 1
(10.5%), or in the presence of (R)-1 (13.5%). As shown in Table 2, increasing the
amount of either (S)-1 or (R)-1 from 1 over 3to 5% led to a higher conversion but
resulted in the same regioselectivity, respectively.
4
)
Fu×s catalysts have also been used for the enantioselective acylation of amines [26] and the construction of
quaternary stereogenic centers [27].
Under analogous conditions, but replacing (S)-1 with Fu×s catalyst ((À)-DMAP-Fe(C5Ph5) complex [25]),
we obtained 41% of 4. Acetylation of 2 under Fu×s conditions [25] gave 54% of the corresponding 3-
acetate. We thank Prof. G. C. Fu, MIT, Cambridge, USA, for a generous gift of his catalyst.
5
)

Helvetica Chimica Acta Vol. 86 (2003)
4371
Scheme 1
OSi(t-Bu)Ph2
O
HO
HO
OMe
OH
2
CH3
N
CH3
N
a)
N
CH3
N
CH3
(R)-1
(S)-1
OSi(t-Bu)Ph2
OSi(t-Bu)Ph2
OSi(t-Bu)Ph2
OSi(t-Bu)Ph2
O
O
O
O
BzO
BzO
HO
RO
BzO
HO
RO
BzO
OMe
OMe
OMe
OMe
OBz
OBz
OH
OH
3 R = H
6 R = Bz
4 R = H
7 R = Bz
5
8
a) BzCl, CH2Cl2, molecular sieves 4 ä, catalyst, base, temperature and reaction time as specified in Tables 1, 2,
and 5.
Table 1. Influence of Reaction Conditions on the Benzoylation of 2 (isolated yields)
Entry Catalyst
Et3N
BzCl
Temp. Time[h] Yielda) [%] of SM and products
[mol-%]
[equiv.] [equiv.] [8C]
2
3
4
5
6
7
b
1
2
3
4
5
6
7
8
0
0
1
1
1.2
1
1
1.2
1.2
1.2
1
À 60
0
24
24
1
1
1
26
9.5
6.5
9
trace
12
2
7
3.3
3.0
19.5
62.5
734
78.5
84
10.5
35
)
4.5
3
c
)
b
b
b
b
(S)-1 (1)
(S)-1 (5) 1.2
(S)-1 (5) 1.2
(S)-1 (5)
(S)-1 (5)
(R)-1 (5)
À 60
)
)
)
)
2.5
d
b
0
)
)
)
)
)
d
À 60
3
5
2.5
2
d
1
1
1
231
29
1.5
47
d
1
1
À 60
1
1
trace
5.8
4
82.5
62
2.5
4
d
À 60
)
13.5
a) Yield of chromatographically pure product. SM: Starting material. b) Dibenzoates and (or) tribenzoates were
detected as minor products in the 1H-NMR spectra, but were not isolated. c) A mixture of 2,3- and 2,4-O-
benzoate was obtained. d) Product not detected.
To check for O-acyl migration, we added the 4-benzoate 5 to the reaction mixture of
2 after consumption of BzCl at À608 (in the presence of (S)-1), monitoring the reaction
for 1 h at this temperature and at 08, then for 12 h at 238, and again at 408 for 2 h. The
ratio of the products did not change up to 238, and very little at 408. In a second
experiment, the 4-benzoate 5 was treated with Et3N (10 equiv.), molecular sieves (4 ä),
and (S)-1 (0.5 equiv.) at À608, and then with additional (S)-1 hydrochloride (0.5
equiv.). TLC of this mixture showed no spot for any of the other mono- or dibenzoates
at temperatures of up to 238.
The Bz groups of all products give rise to the typical IR bands around 1715 cmÀ1 and to 13C signals around
168 ppm. The NMR spectra are characterized by a downfield shift of 1.0 2.0 ppm for the 1H geminal to the BzO
group, a downfield shift of ca. 2 ppm for the benzoyloxylated 13C, and an upfield shift of ca. 2 ppm for the vicinal
13C [11].

4372
Helvetica Chimica Acta Vol. 86 (2003)
Table 2. Influence of the Amount of (S)-1 and (R)-1 onthe Benzoylationof 2 (ratio of products)
Entry Catalyst
NEt3
BzCl
Temp. Time Yielda) [%] of SM and products
([mol-%]) [equiv.] [equiv.] [8]
[h]
2
3
4
5
6
7
b
1
2
3
4
5
6
(S)-1 (1)
(R)-1 (1)
(S)-1 (3)
(R)-1 (3)
(S)-1 (5)
(R)-1 (5)
1
1
1
1
1
1
1
1
1
1
1
1
À 60
À 60
À 60
À 60
À 60
À 60
1
1
1
1
1
1
9.5
15.4
6.0
10.0
4.8
8.2
4.9
)
80.8
58.4
85.0
63.3
85.1
64.5
)
1.9
4.4
1.9
4.1
2.1
5.0
2.8
5.0
2.4
6.0
3.0
6.4
b
16.7
b
4.7
)
b
)
16.6
b
5.0
)
b
)
16.0
a
) Ratio (in %) determined by integration of the H-NMR HÀC(l) signals. SM: Starting material. b) Product
1
not detected.
The 1H-NMR spectrum of 4 shows couplings between the signals at 5.21 (t, J ꢀ 9.1) and at 3.62 (ddd, J ˆ 9.5,
7.5, 2.9, HÀC(2)). The structures of 3 and 5 were also assigned on the basis of decoupling experiments. The
dibenzoate 6 showed signals at 5.49 (−t×, J ˆ 10.0) and 5.40 (dd, J ˆ 10.0, 7.8), evidencing that the BzO groups are
located at C(2) and C(3). The structure of the dibenzoate 7 was evidenced by the absence of a coupling of the
deshielded H-atom with HÀC(1), resonating at 4.45 ppm (d, J ˆ 7.8 ) . The 13C-NMR spectra of the benzoates
are in agreement with these assignments.
The triol 2 may be considered a combination of two 1,2-diol substructures, one com-
prising C(2)ÀOH and C(3)ÀOH, the other one comprising C(3)ÀOH and C(4)ÀOH.
The first substructure may be compared to (S,S)-trans-cyclohexane-1,2-diol and the latter
to its enantiomer. We, therefore, wondered about the kinetic resolution (Scheme 2) of
racemic 9 by mono- and dibenzoylation in the presence of (S)-1 or (R)-1. While the sequen-
tial kinetic resolution of the diacetate of 9 by porcine liver esterase (PLE) [37] and lipase
[38] is well-known, we are not aware of reports on the enantioselective O-acylation of 9.
Oriyama et al. found that OH groups at (S)-configured C-atoms are preferentially
acylated in the presence of catalytic amounts of (S)-1 [34]. Acylation of the homotopic
OH groups of (R,R)-9 or (S,S)-9 should reflect the influence of (S)-1 or (R)-1 on the
acylation of a pair of trans-1,2-diols in the absence of constitutional differences between
the OH groups. The enantiomerically pure monobenzoate 10 and dibenzoate 11,
required as a reference (Entry 1 in Table 3), were obtained by benzoylation of
enantiomerically pure (S,S)-9. As expected, use of (S)-1 or (R)-1 for the benzoylation
of racemic 9 gave parallel results (Table 3, Entry 2 7), although the diol did not
dissolve completely in CH2Cl2 at À6086). A comparison of Entries 2 and 4
(benzoylation in the presence of 1 mol-% of (S)-1) shows that doubling the amount
of Et3N and BzCl from 0.5 and 0.6 to 1.0 and 1.2 equiv., respectively, raised the yield of
the monobenzoates from 31.8 to 51.8%, while the ee, in favour of the (S,S)-enantiomer,
dropped from 28.3to 4.4%. Entry 6 shows that a further increase of the amount of Et3N
and BzCl to 1.5 and 1.8 equiv., respectively, decreased the yield of the monobenzoate 10
to 45%, while the ee increased to 79.6%, but now in favour of the (R,R)-enantiomer.
Parallel to this, the yield of the dibenzoate 11 increased from 8.6 over 22.8 to 52.2%,
with a decrease in ee from 94 to 93.1 to 77.3% in favour of the (S,S)-enantiomer. A
comparison of Entries 3, 5, and 7 shows that (R)-1 leads to parallel results. Entry 8
shows that an increase of the concentration and a smaller amount of reagents (0.5 equiv.
6
)
Starting material, catalyst, and Et3N were dissolved at 238, cooled to À608, and then treated with BzCl.

Helvetica Chimica Acta Vol. 86 (2003)
4373
BzCl, 0.6 equiv. Et3N) lowered both the yield and ee of 10 and slightly increased the
yield of 11, while lowering its ee. The enantioselective benzoylation of the racemic
monobenzoate 10 in the presence of 5 mol-% of (S)-1 or (R)-1 yielded 41% of (S,S)-11
or (R,R)-11 (ee 79 80%, Entries 9 and 10). The advantage of sequential kinetic
resolutions7) are well-documented, and a comparison of Entries 3 and 10 teaches that
the second benzoylation (proceeding more slowly) is more selective than the first one.
That (S,S)-9 was preferentially benzoylated in the presence of (S)-1 and that (R,R)-9
was preferentially benzoylated in the presence of (R)-1 is in agreement with the
observation of Oriyama et al. who also showed that the enantioselectivity is influenced
by the nature of a vicinal substituent [33][34].
Scheme 2
OH
OH
OBz
OBz
OBz
OH
a)
+
9
10
11
a) (S)-1 or (R)-1 or N,N,N',N'-tetramethylethylenediamine (TMEDA), Et3N, BzCl, molecular sieves (4 ä),
CH2Cl2, À608, 24 h.
Table 3. Benzoylation of trans-Cyclohexane-1,2-diol (9)
Entry Substrate Catalyst
Et3N
BzCl
CH2Cl2 Temp. Time Monobenzoate 10
Dibenzoate 11
Yieldb) eed)
[%]
([mmol]) ([mol-%])a) [mmol] [mmol] [ml]
[8]
[h]
Yieldb) eec)
[%]
1
2
(1S,2S)-9 (S)-1
0.5
0.5
0.5
1.0
0.5
0.6
0.6
1.2
8
10
10
10
10
10
10
10
6
À 60
À 60
À 60
À 60
À 60
À 60
À 60
À 60
À 60
À 60
24
24
24
24
24
24
24
24
24
24
73.0
> 99.5(S) 11.5
28.3 (S) 8.6
> 99.5 (S)
(0.5)
(Æ)-9
(1.0)
(Æ)-9
(1.0)
(Æ)-9
(1.0)
(Æ)-9
(1.0)
(Æ)-9
(1.0)
(Æ)-9
(1.0)
(Æ)-9
(5.0)
(Æ)-10
(0.5)
(Æ)-10
(0.5)
(5.0)
(S)-1
(1.0)
(R)-1
(1.0)
(S)-1
(1.0)
(R)-1
(1.0)
(S)-1
(1.0)
(R)-1
(1.0)
(S)-1
(5.0)
(S)-1
(5.0)
(R)-1
(5.0)
31.8
94.0 (S)
94.8 (R)
93.1 (S)
92.9 (R)
77.3( S)
81.7 (R)
88.2 (S)
79.9 (S)
78.9 (R)
3
31.8
31.9 (R) 8.0
4.4 (S) 22.8
4.4 (R) 21.6
79.6 (R) 52.2
S) 52.5
4
51.8
5
1.0
1.2
52.7
6
1.5
1.8
45.0
7
1.5
1.8
42.382.9 (
20.8
8
3.3
0.25
0.25
2.5
0.25
0.25
< 0.5
12.1
9
56.4
59.2 (R) 41.4
60.3( S) 41.4
10
6
54.5
a) Relative to Et3N with exception of Entry 8 where the mol-% is relative to BzCl. b) Yield of chromatographically pure
product. c) Determined by HPLC (Chiralpak AS; hexane/i-PrOH 90 : 10; 1.0 ml/min). d) Determined by HPLC (Chiralpak
AS; hexane/i-PrOH 98 : 2; 0.8 ml/min).
7
)
For sequential resolutions by enzymes, see [39][40], and references cited therein.

4374
Helvetica Chimica Acta Vol. 86 (2003)
On the basis of the moderate preferential benzoylation of (S,S)-trans-cyclohexane-
1,2-diol (9) under the influence of (S)-1, one expects that this catalyst will lead to a
preferential benzoylation of 2 at C(2)ÀOH rather than C(4)ÀOH, while the opposite
should hold for the influence of (R)-1, unless constitutional differences resulting in a
larger hindrance of C(4)ÀOH will prevail.
Benzoylation of 2 at À608 in the presence of (S)-1 (Entry 7, Table 1) gave indeed,
besides the major 3-benzoate 4, 4% of the 2-benzoate 3, but no 4-benzoate 5, while (R)-
1 gave 13.5% of 4-benzoate 5 and no 2-benzoate 3 (Entry 8, Table 1). A second
benzoylation of the 3-benzoate 4, however, led independently of the sense of the
chirality of 1 preferentially to the 2,3-dibenzoate 6 (Table 4). Entries 1 and 2 also show
a similar ratio of 2,3-dibenzoate to 3,4-dibenzoate (Entry 1, 70 :30; Entry 2, 68 :32),
independently of whether the reaction is conducted for 1 or for 12 h (Entry 3, 71:29;
Entry 4, 71:29). This may reflect the increased steric hindrance of C(4)ÀOH by
C(3)ÀOBz rather than the requirement for a vicinal OH group, considering that (S)-1
has led to a kinetic resolution of racemic monoalcohols [33].
Table 4. Influence of Catalysts on the Benzoylation of 4
Entry
Catalyst
([mol-%])
Et3N
[equiv.]
BzCl
[equiv.]
Temp.
[8]
Time
[h]
Ratioa) [%] of SM and products
4
6
7
8
6/7
1
2
3
4
(R)-1 (5)
(S)-1 (5)
(R)-1 (5)
(S)-1 (5)
1.1
1.1
1.1
1.1
1
1
1
1
À 60
À 60
À 60
À 60
1
1
12
12
72.5
86.9
42.8
73.7
19.0
8.9
37.7
18.1
8.3trace
4.2
15.2
7.3
070 : 3
0
4.4
0.8
68 : 32
71 : 29
71 : 29
a) Ratio (in %) determined by integration of the HÀC(1) signals in the 1H-NMR spectra. SM: Starting material.
These observations suggest that constitutional differences between the three OH
groups of 2 determine the regioselectivity of the benzoylation to a much larger extent
than the absolute configuration of 1. The regioselectivity correlates indeed with the
expected nucleophilicity of the individual OH groups. The nucleophilicity of C(2)ÀOH
is impaired by its proximity to the anomeric center, and that of C(4)ÀOH by its more-
pronounced steric hindrance. It follows that the higher regioselectivity and yield of
benzoylation in the presence of (S)-1 is rather due to the influence of its constitution
than of its configuration, and that achiral ditertiary 1,2-diamines may similarly increase
the intrinsic reactivity difference of the OH groups of 2.
A comparison of the use of (S)-1 and N,N,N',N'-tetramethylethylenediamine
(TMEDA) as catalysts for the benzoylation of 2 at À608 gave the following results: the
monobenzoates, the dibenzoates, and the tribenzoate are formed in a ratio of 95 :5 :0
(95%; 5% starting material) for (S)-1 and 70 :30 :0 (77%; 22% starting material) for
TMEDA (Entries 3 and 17, Table 5), the ratio of the monobenzoates 3, 4 and 5 is
6 :94 :0 (90%) for (S)-1 and 4 :90 :6 (53.6%) for TMEDA, and the ratio of the 2,3- to
the 3,4-dibenzoates is 41:59 (5.1%) for (S)-1 and 35 :65 (23.4%) for TMEDA.
These results show that TMEDA is a more active catalyst than (S)-1, at least for the
second benzoylation. This is seen from the increased amount of dibenzoates,
correlating with a larger amount of remaining starting material, the formation of the
hindered 4-benzoate 5, and the slightly changed ratio of the 3,4- vs. 2,3-dibenzoates (6/7

Helvetica Chimica Acta Vol. 86 (2003)
4375
Table 5. Influence of Catalysts and Reaction Conditions on the Benzoylation of 2
Entry Catalyst
Base
BzCl
Temp. Time Ratioa) of SM and products (isolated yield)
([mol-%])
([equiv.])
[equiv.] [8]
[h]
2
3
4
5
6
7
1
2
3
4
5
6
7
8
9
10b)
11b)
12b)
13b)
14
15
16
17
18
19
20
21
22
23
24
25
26
27
(S)-1 (5)
(R)-1 (5)
(S)-1 (5)
(R)-1 (5)
Et3N (1)
Et3N (1)
Et3N (1)
Et3N (1)
Pyridine (1)
Pyridine (1)
Pyridine (1)
Pyridine (1)
Pyridine (1)
Et3N (1)
1
1
0
0
1
1
1
1
1
1
1
13.1
17.9
4.8 (0)
8.2 (6)
33.9
4.2
2.4
76.1
58.5
2.6
11.6
-
2.3
4.9
2.1 (2)
5.0 (4)
7.6
5.9
4.0
1.0
1.7
4.8
3.0 (2)
6.4 (2)
2.9
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
À 60
À 60
À 60
À 20
0
5.0 (4) 85 (82)
-
64.5 (62) 16 (14)
7.5
7.6
6.7
27.4
41.1
24.5
4.8
43.9
45.4
37
4.2
4.9
5.4
33.8
44.4
2.3
1.7
231
2348 4.03
58.4
5.6
8.6
4.0
4.8
.5 3
8.8
4.32.4
1.4
À 60
1
1
42.37
44.0
17
40.8
5.4
Et3N (1)
Et3N (1)
Et3N (1)
0
7.2
trace
6.8 (4)
7.2 .6
trace
1.3
231
2324
49.4
2.7
40.3
1.1
24.4 (21) 1.8 (1) (6538)
2.1 (1)
2.0 (2)
TMEDA (50)
TMEDA (100)
TMEDA (100)
TMEDA (5)
TMEDA (5)
TMEDA (5)
TMEDA (5)
À 60
1
1
1
1
1
1
26.31.1
25.4
46.34.1
1.5
13
À 60
48.6
5.0
6.9
11.6
8.5 (7)
8.3 (7) 15.1 (10)
0
20.9 (14) 2.2 (0) 54.5 (54) 4.5 (4)
21.7 (17) 2.2 (2) 48.0 (46) 3.4 (2)
19.0
23.3
20.8
68.4
44
8.6 (9)
Et3N (1)
Et3N (1)
Et3N (1)
Et3N (1)
À 60
0
23
2.7
3.7
55
51
3.7
4.9
9.7
9.4
7.3
1.5
2.2
2.0
9.1
7.0
2348
.63
52.4
5.1
10.1
trace
6.4
2.3
4.1
TEEDAc) (5) Et3N (1)
TEEDA (5)
TEEDA (5)
TEEDA (5)
À 60
1
1
8.0
4.2
45.1
64.9
9.310.9
39.1
Et3N (1)
Et3N (1)
Et3N (1)
EtNMe2 (1)
Et3N (1)
Et3N (1)
0
1.2
231
2348
41
19.1
.1 3
.13
6.4
6.4
2.5
À 60
1
1
1
35.4 (26) 19.6 (20) 10.5 (10) 12.9 (13) 12.5 (12) 7.7 (5)
24.9 (15) 21.5 (21) 11.4 (11) 16.7 (16) 16.7 (16) 8.2 (8)
25.1
EtNMe2 (5)
EtNMe2 (10)
À 60
À 60
21.6
11.6
17.2
16.1
8.1
a) Ratio (in %) determined by integration of the 1H-NMR HÀC(1) signals. SM: Starting material. b) 1 4% of 2,4-O-
dibenzoate were observed from the corresponding H-NMR spectrum. c) TEEDA: N,N,N',N'-Tetraethylethylenediamine.
1
6 :4 vs. 7:3 ;cf. Table 4). The regioselectivity of the monobenzoylation of 2 at
C(2)ÀOH and C(3)ÀOH, i.e., the ratio 3/4, is only slightly affected by replacing (S)-1
with TMEDA. The higher reactivity of TMEDA vs. (S)-1 correlates with the smaller
size of its N-substituents. Indeed, as judged from the amount of remaining starting
material, N,N,N',N'-tetraethylethylenediamine (TEEDA) was not as effective as
catalyst, particularly at À608 (Table 5, Entries 21 24). It leads, however, to a slightly
improved regioselectivity (Table 5, Entries 20 and 24). The effect of size was further
evaluated by comparing Et3N with EtNMe2. A comparison of the Entries 10 and 25
shows that EtNMe2 is more reactive than Et3N (less starting material and higher
amount of dibenzoates), but less selective. The effect of the second amino group was
tested by adding catalytic amounts of either TMEDA or EtNMe2 (Entries 17 and 26).
The higher regioselectivity resulting from using ditertiary 1,2-diamines may be
rationalised by postulating the intermediate formation of a reactive complex [31] that
deprotonates (partially) a OH group and transfers the Bz residue to it, in a concerted
and quasi-intramolecular way. Indeed, comparing TMEDA and EtNMe2 shows that the

4376
Helvetica Chimica Acta Vol. 86 (2003)
mere size of the reaction complex does not explain the differences of regioselectivity.
The effect of factors besides the configuration (steric hindrance?) is evidenced by the
observation that both (S)-1 and (R)-1 lead to higher yields of the 3-benzoate 4 than
TMEDA (cf. Table 6 below).
The regioselectivity of the benzoylation of the a-d-anomer 12 [41] (Scheme 3 and
Table 6) is more strongly affected by the catalyst. Benzoylation in the presence of (S)-1
Scheme 3
OSi(t-Bu)Ph2
OSi(t-Bu)Ph2
OSi(t-Bu)Ph2
O
O
O
HO
HO
HO
BzO
+
+
BzO
HO
OSi(t-Bu)Ph2
BzO
HO
HO
OMe
OMe
OMe
O
15
13
14
HO
HO
a)
OSi(t-Bu)Ph2
OSi(t-Bu)Ph2
HO
OMe
O
O
HO
BzO
BzO
12
+
HO
BzO
BzO
OMe
OMe
16
17
OSi(t-Bu)Ph2
OSi(t-Bu)Ph2
OSi(t-Bu)Ph2
HO
BzO
HO
HO
BzO
HO
O
O
O
b)
OMe
OMe
OMe
+
OH
OH
OH
18
19
20
OSi(t-Bu)Ph2
OSi(t-Bu)Ph2
OSi(t-Bu)Ph2
OSi(t-Bu)Ph2
HO
HO
HO
BzO
HO
HO
O
O
O
a)
O
HO
+ BzO
+
BzO
HO
BzO
HO
OMe
21
OMe
OMe
OMe
22
23
24
OSi(t-Bu)Ph2
OSi(t-Bu)Ph2
OH
O
OH
O
a)
HO
HO
HO
OMe
OMe
BzO
25
26
OSi(t-Bu)Ph2
OSi(t-Bu)Ph2
OH
O
OBz
O
HO
HO
HO
+
OSi(t-Bu)Ph2
OH
O
BzO
OMe
OMe
a)
HO
HO
29
28
OSi(t-Bu)Ph2
OSi(t-Bu)Ph2
OBz
O
OMe
OBz
O
27
BzO
HO
HO
BzO
+
OMe
OMe
30
31
a) (S)-1 or (R)-1 or TMEDA, Et3N, BzCl, molecular sieves (4 ä), CH2Cl2, À608, 1 h. b) (S)-1 or (R)-1 or
TMEDA, Et3N, BzCl, molecular sieves (4 ä), CH2Cl2, À58, 1 h.

Helvetica Chimica Acta Vol. 86 (2003)
4377
Table 6. Benzoylation of Methyl 6-O-TBDPS a- or b-d-Glycopyranosides Catalyzed by (S)-1 or by (R)-1 or by
TMEDA at À 608
Substrates (configuration)
Yield [%]a)b)
2-Benzoate
3-Benzoate
4-Benzoate
Others
2 (b-d-gluco)
Cat. by (S)-1
Cat. by (R)-1
Cat. by TMEDA
3 (4)
3 (1)
4 (82.5)
4 (62)
4 (53)
6 (2.5), 7 (2.5)
6 (4), 7 (2)
6 (7.5), 7 (12.5)
5 (13.5)
5 (2.5)
12 (a-d-gluco)
Cat. by (S)-1
Cat. by (R)-1
Cat. by TMEDA
13 (82)
13 (11)
13 (64)
14 (7)
14 (28)
14 (3.5)
16 (3.4)
16 (12), 17 (7)
16 (13), 17 (4)
15 (10)
18 (b-d-galacto)c)
Cat. by (S)-1
Cat. by (R)-1
b
19 (68)
19 (61)
19 (56)
trace
20 (6)
20 (4)
)
)
)
b
b
Cat. by TMEDA
21 (a-d-galacto)
Cat. by (S)-1
Cat. by (R)-1
Cat. by TMEDA
22 (78)
22 (10)
22 (69)
23 (2)
23 (57)
23 (2)
24 (3)
24 (8)
24 (9)
25 (b-d-manno)
Cat. by (S)-1
Cat. by (R)-1
26 (86)
26 (63)
27 (a-d-manno)
Cat. by (S)-1
Cat. by (R)-1
Cat. by TMEDA
28 (8)
28 (47)
28 (12)
29 (86)
29 (10)
29 (34)
30 (6), 31 (10)
30 (6), 31 (3)
a) Yield of chromatographically pure product. b) Some minor isomers and recovered starting material are not
considered in this table. c) Benzoylation took place at À58.
gave mostly the 2-benzoate 13 [42] (82%) besides the 3-benzoate 14 (7%) and the 2,3-
dibenzoate 16 (3.4%), while benzoylation in the presence of (R)-1 resulted in a poor
regioselectivity, leading to the monobenzoates 13 (11%), 14 (28%), and 15 (10%), and
the dibenzoates 16 (12%) and 17 (7%).
As shown in Table 6, TMEDA led to intermediary yields of the major 2-benzoate 13
(64 vs. 82% resulting from the use of (S)-1, and 11% from the use of (R)-1), but to
lower yields of the 3-benzoate 14 (3.5%) than either one of the other two catalysts
(similarly to the 3-O-benzoylation of the b-d-anomer 2). The interpretation of this
result is, however, not possible, considering the large amount of dibenzoates formed in
the presence of TMEDA. Also in agreement with the effect of the diamines on the
regioselectivity of the benzoylation of 2 is the higher yield of the 4-benzoate 15 in the
presence of (R)-1. The dominant intrinsic factor determining the regioselectivity
appears to be the C(2)ÀOH ¥¥¥ OÀC(1) H-bond, determining the relative nucleophi-
licity of the OH groups. Studies of this effect go back to Foster and co-workers [43] who
showed that the regioselectivity of the acylation by acyl chlorides is determined by this
intramolecular H-bond, if the rate-determining step involves attack of a non-ionised
OH group on the acylating agent. Recently, Yoshida et al. [44] reported that an

4378
Helvetica Chimica Acta Vol. 86 (2003)
intramolecular H-bond network plays a decisive role in the relative reactivities of OH
groups of unprotected carbohydrates in the DMAP-catalyzed acylation.
Benzoylation of the anomeric galactopyranosides 18 [45] and 21 [46] also shows the
well-known influence of a H-bond from an equatorial OH group to a vicinal, axial OH
or OR substituent [2]. As seen from Table 6, the regioselectivity of the benzoylation of
the b-d-anomer 18 is determined by the C(3)ÀOH ¥¥¥ OÀC(4) H-bond; there is little
influence of the nature of the catalyst, TMEDA leading to the lowest and (S)-1 to the
highest yield (68%) of the 3-benzoate 19. In contradistinction, benzoylation of the a-d-
galactopyranoside 21 reflects the competing effects of the C(2)ÀOH ¥¥¥ OÀC(1) and
the C(3)ÀOH ¥¥¥ OÀC(4) H-bonds and the influence of the catalyst. The highest yield
of the 2-O-benzoate 22 (78%) was obtained in the presence of (S)-1. Benzoylation in
the presence of (R)-1 provided 22 in only 10% yield; the major product was the 3-
benzoate 23 (57%). TMEDA yielded 22 in an intermediary yield of 69%; like (S)-1, it
led to 23 in only minor amounts (2%).
The lower reactivity of axial OH groups, the effect of the C(3)ÀOH ¥¥¥ OÀC(2) H-
bond, and the effect of the catalyst are also evident from the benzoylation of the
anomeric mannopyranosides 25 [47] and 27 [48]. Benzoylation of the b-d-mannopy-
ranoside produced essentially the 3-benzoate 26, and the influence of the nature of the
catalyst is evidencd by the yield of 86% ((S)-1) vs. 63% ((R)-1). Benzoylation in the
presence of (S)-1 of a-d-mannopyranoside 27 provided 86% of the 3-benzoate 29 [48];
yields dropped to 10% with the enantiomeric catalyst, while TMEDA led to an
intermediary result. The best yield of the 2-benzoate 28 (47%) resulted from using (R)-
1; again, intermediary results were obtained in the presence of TMEDA.
The structure of the 3-benzoate 14 was evidenced by the transformation of the HÀC(2) td at 3.74 (J ˆ 10.0,
3.7) to a d (J ˆ 3.7) upon addition of D2O and irradiation of the t at 5.33 (J ˆ 9.3). The structure of the 4-
benzoate 15 was confirmed by comparison of its NMR spectra with those of 13 [42] and of 14; it is evidenced by
the dd at 5.17 (J ˆ 9.9, 9.3), which shows no coupling with the d at 4.88 (J ˆ 3.7, HÀC(1)). The coupling between
the d at 5.10 (J ˆ 3.7, HÀC(1)) and the dd at 5.21 (J ˆ 10.2, 3.7) of 16, and the coupling between the d at 5.13
(J ˆ 3.7, HÀC(1)) and the dd at 5.09 (J ˆ 9.3, 3.7) of 17 show that C(2)ÀOH in these compounds is O-
benzoylated. The dd at 5.77 (J ˆ 10.2, 9.0, irrad. at 5.21 ! br. d, irrad. at 3.95 ! d, J ˆ 10.2, HÀC(3)) of 16
evidences 2,3-O-dibenzoylation. The t at 5.31 (J ˆ 9.5, irrad. at 4.38 ! d, J ˆ 9.3, irrad. at 4.05 ! d, J ˆ 9.0,
HÀC(4)) of 17 evidenced 2,4-O-benzoylation. The br. d at 5.74 (J ꢀ 3.0) of 20 evidences benzoylation at
C(4)ÀOH. The s at 167.0 ppm of 22 and s at 166.6 ppm of 23 evidence one CˆO group for each compound.
Benzoylation at C(2)ÀOH of 22 is deduced from the coupling between the dd at 5.23ppm ( J ˆ 9.7, 3.7,
HÀC(2)) and the d at 5.01 ppm (J ˆ 3.7, HÀC(1)). The structure of 23 was evidenced by the absence
of a coupling between the dd at 5.26 ppm (J ˆ 10.2, 3.0, HÀC(3)), showing one large coupling, and the d at
1
4.87 ppm (J ˆ 3.7, HÀC(1)). The H- and 13C-NMR spectra of 24 are identical to those described in [46]. The
absence of a coupling between the dd at 5.06 (J ˆ 9.5, 2.9) and the d at 4.51 (J ˆ 0.8, HÀC(1)), and the coupling
between the dd at 5.06 and the td at 4.21 (J ˆ 2.9, 0.8, addition of D2O ! br. d, J ꢀ 3.3, HÀC(2)) reveal the
benzoylation at C(3)ÀO of 26. The structure of the 2-benzoate 28 was assigned on the basis of the coupling
between the dd at 5.35 (J ˆ 2.8, 1.5, irrad. at 4.82 ! d, J ˆ 2.8, HÀC(2)) and the d at 4.82 (J ˆ 1.7, irrad. at 5.35 !
s, HÀC(1)). The dd at 5.34 (J ˆ 9.65, 3.2) of 29 [48] evidences benzoylation at C(3)ÀO. The two 13C signals at
166.8 and 165.8 ppm of 30, and the 13C signals at 167.3and 166.2 ppm of 31 evidence two CˆO groups in each
compound. The structure of 30 was evidenced by the absence of coupling between the d at 4.89 (J ˆ 1.2,
HÀC(1)) and the br. t at 4.39 (J ꢀ 9.3), showing two large couplings (addition of D2O ! change to a sharp t,
HÀC(4)). The structure of 31 was evidenced by the m at 4.38 4.26 (addition of D2O ! dd, J ˆ 10.0, 3.4,
HÀC(3)).

Helvetica Chimica Acta Vol. 86 (2003)
4379
To further evaluate the extent to which the nature of the catalyst influences the
regioselectivity of the benzoylation, we examined the anomeric pairs of the 4,6-O-
benzylidenated glycopyranosides 32 [49] and 36 [49], 40 [50] and 43 [50], and 47 [51]
and 49 [50] (Scheme 4 and Table 7).
Benzoylation of the benzylidenated allyl b-d-glucopyranoside 32 was little affected
by the nature of the catalyst. Regioselectivity was low, with the 3-benzoate 34 produced
in higher amounts than the 2-benzoate 33; some 2,3-dibenzoate 35 was also isolated.
The regioselectivity for 32 is lower than the one for 2, evidencing an influence of
C(4)ÀOH on the benzoylation at C(3)ÀO. Benzoylation of the a-d-anomer 36 was
again dominated by the intramolecular C(2)ÀOH ¥¥¥ OÀC(1) H-bond, yielding mostly
the 2-benzoate 37 [5] (83.5% in the presence of (S)-1). The 3-benzoate 38 and the 2,3-
dibenzoate 39 are by-products, particularly when (R)-1 is used.
Scheme 4
O
O
O
O
Ph
Ph
Ph
Ph
O
O
O
O
O
O
O
O
OAllyl
OAllyl
OAllyl
OAllyl
BzO
HO
BzO
HO
a)
+
+
OBz
OH
OBz
OH
32
36
33
34
35
O
O
O
O
Ph
Ph
Ph
Ph
O
O
O
O
O
O
O
O
a)
HO
HO
BzO
+
BzO
+
HO
BzO
BzO
HO
OAllyl
OAllyl
OAllyl
OAllyl
37
38
39
Ph
O
Ph
Ph
O
O
O
O
O
a)
O
OBz
O
O
+
OMe
BzO
OMe
HO
BzO
OMe
OH
OH
40
41
42
Ph
Ph
O
Ph
Ph
O
O
O
O
O
O
O
O
a)
a)
O
HO
O
O
HO
BzO
BzO
HO
+
+
BzO
BzO
HO
OMe
OMe
OMe
OMe
OMe
43
47
44
45
46
OH
O
OH
O
O
Ph
Ph
O
O
O
OMe
HO
BzO
48
OH
O
OBz
O
OBz
O
OH
O
Ph
O
Ph
Ph
O
O
O
O
Ph
a)
O
O
O
+
+
BzO
BzO
HO
HO
OMe
OMe
OMe
OMe
51
49
50
52
a) (S)-1 or (R)-1 or TMEDA, Et3N, BzCl, molecular sieves (4 ä), CH2Cl2, À608, 1 h.

4380
Helvetica Chimica Acta Vol. 86 (2003)
Table 7. Benzoylation of Allyl or Methyl 4,6-O-Benzylidene a- or b-d-Glycopyranosides Catalyzed by (S)-1 or
(R)-1 or TMEDA at À 608
Substrates (configuration)
Yield [%]a)
2-Benzoate
3-Benzoate
2,3-Dibenzoate
32 (b-d-gluco)
Cat. by (S)-1
Cat. by (R)-1
33 (20)
33 (21)
34 (47)
34 (30)
35 (5)
35 (9)
36 (a-d-gluco)
Cat. by (S)-1
Cat. by (R)-1
37 (83.5)
37 (81)
38 (3)
38 (9)
39 (2)
42 (5)
40 (b-d-galacto)
Cat. by (S)-1
Cat. by (R)-1
Cat. by TMEDA
41 (83)
41 (83)
41 (84)
43 (a-d-galacto)
Cat. by (S)-1
Cat. by (R)-1
Cat. by TMEDA
44 (46)
44 (26)
44 (64)
45 (33)
45 (54)
45 (6)
46 (7)
46 (10)
46 (15)
47 (b-d-manno)
Cat. by (S)-1
Cat. by (R)-1
48 (90)
48 (62.5)
49 (a-d-manno)
Cat. by (S)-1
Cat. by (R)-1
Cat. by TMEDA
50 (6)
50 (19)
50 (8)
51 (85)
51 (62)
51 (74)
52 (4)
52 (9)
a) Yield of chromatographically pure product.
As expected from the C(3)ÀOH ¥¥¥ OÀC(4) H-bond [52] in methyl 4,6-O-
benzylidene-b-d-galactopyranoside 40 [50], the 3-benzoate 41 [53] was the major
product in the presence either of (R)-1 (83%), of (S)-1 (83%), or of TMEDA (84% of
41 and 5% of the 2,3-dibenzoate 42 [53] [54]). Benzoylation of the a-d-anomer 43,
however, showed again the competing effect of the C(2)ÀOH ¥¥¥ OÀC(1) and the
C(3)ÀOH ¥¥¥ OÀC(4) H-bonds and the influence of the catalyst, (S)-1 leading to 46%
of the 2-benzoate 44 [53], 33% of the 3-benzoate 45 [53], and 7% of 2,3-dibenzoate 46
[53], (R)-1 leading to 26% of 44, 54% of 45, and 10% of 46, and TMEDA to 64% of
44, 6% of 45, and 15% of 46.
Benzoylation of the anomeric mannopyranosides 47 and 49 reflects the same factors
that dominated the benzoylation of the anomeric silylated mannopyranosides 25 and
27. Benzoylation of the b-d-mannopyranoside 47 gave mostly the 3-benzoate 48 [65],
isolated in 90% yield ((S)-1) or 62.5% ((R)-1). Benzoylation of the a-d-mannopyrano-
side 49 was less strongly influenced by the catalysts than that of 27, providing 85, 62, and
74% of the 3-benzoate 51 [55] as the major product in the presence of (S)-1, (R)-1, and
TMEDA, respectively.
The structure of 34 was evidenced by a single CˆO s at 166.6 ppm and the absence of a coupling between
the t at 5.49 (J ˆ 9.5) and the d at 4.6 (J ˆ 7.8, HÀC(1)). The assignment was confirmed by decoupling
experiments. Addition of D2O simplified the ddd at 3.76 (J ˆ 9.4, 7.5, 3.1) to a dd (J ˆ 9.4, 7.8). Irradiation, after

Helvetica Chimica Acta Vol. 86 (2003)
4381
the addition of D2O, of the t at 5.49 further simplified the dd at 3.76 to a d (J ˆ 7.2); similarly, irradiation of the d
at 4.60 simplified the dd at 3.76 to a d (J ˆ 9.0).
Benzoylation of partially protected monosaccharides with BzCl and Et3N or
EtNMe2 in the presence, or absence, of catalytic amounts of either ditertiary 1,2-
diamines or EtNMe2 proceeded with various degrees of regioselectivity. The
regioselectivity depended mostly on the constitution and configuration of the starting
diols and triols.
Since acyl migration was excluded, regioselectivity reflects the relative nucleo-
philicity of the individual OH groups. Factors determining the nucleophilicity have
been reported [2]; they comprise the equatorial or axial orientation of OH groups,
intramolecular H-bonds of equatorial OH groups to germinal cis-OR substituents, the
distance to the anomeric center, and steric hindrance. The nature of the catalysts used
in this study only modulates these effects, to a larger or smaller extent, depending on
how strong and how convergent the structural factors are.
A comparison with the yields resulting from benzoylation by established methods
shows no general advantage of using 1 or TMEDA. Both, benzoylation following
stannylation [11][14][42][56] or benzoylation with 1-benzoyl-1H-benzotriazole
[5][6][57] resulted in higher or similar yields. Exceptions are the benzoylation of 2,
21, 25, 43, and 47. Benzoylation of the 6-O-silylated b-d-glucopyranoside 2 in the
presence of 5 mol-% (S)-1 provided 82 84% of the 3-benzoate 4. No alternative
method was found, but benzoylation of methyl b-d-glucopyranoside with 1-benzoyl-
oxy-1H-benzotriazole (3.3 equiv.) gave 60% of the 3,6-dibenzoate [6].
Regioselective benzoylation of 6-O-protected a-d-galactopyranosides is difficult.
In the presence of 5 mol-% (S)-1, 21 yielded 78% of the 2-benzoate 22, while (R)-1 led
mostly (57%) to the 3-benzoate 23. This should be compared to the benzoylation of 21
with 2.2 equiv. BzCl and pyridine that yielded 64% of the 2,3-dibenzoate 24 [46], and to
the benzoylation of methyl a-d-galactopyranoside that gave a complex mixture of
monobenzoates and dibenzoates [14].
Benzoylation of methyl 4,6-O-benzylidene-a-d-galactopyranoside (43) in the
presence of (R)-1 provided 54% of the 3-benzoate 45 besides 26% of the regioisomer
44, while TMEDA led to 64% of 44 besides 6% of 45. By comparison, 1-benzoyloxy-
1H-benzotriazole led to these isomers in a 1:1 ratio [6]. BzCl/pyridine provided 44 and
45 in 20 and 30% [53], BzCl/pyridine in CHCl3 provided 44 and 45 in 10 and 46% [58],
and BzCN/Et3N in 21 and 40% yields, respectively [53].
The regioselective benzoylation of 4,6-O-benzylidene-b-d-mannopyranoside 47 is
new, and no examples were found for the regioselective benzoylation of C(6)ÀO-
protected b-d-mannopyranosides. Perhaps more important than the higher yields
resulting, in these few examples, from benzoylation in the presence of ditertiary 1,2-
diamines is the operational simplicity and the advantage of avoiding stannyl
derivatives.
We thank Dr. B. Lohri and Dr. R. Schmid, F. Hoffman-La Roche AG, Basel, for stimulating information,
Dr. K. Ruda and Mr. P. Zarotti for exploratory experiments, Dr. B. Bernet for checking the Exper. Part., and F.
Hoffman-La Roche AG, Basel, for generous support.

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Helvetica Chimica Acta Vol. 86 (2003)
Experimental Part
General. Solvents were removed under reduced pressure (rotatory evaporator). CH2Cl2 was distilled over
CaH2, and THF was distilled over Na/benzophenone before use. DMF was dried over 4-ä molecular sieves.
Et3N was distilled over CaH2 and kept over 4-ä molecular sieves. Melting points were measured with a B¸chi
510 apparatus and are uncorrected. Optical rotations [a] were determined at 589 nm. IR Spectra were recorded
on a Perkin-Elmer 298 FT-IR spectrometer. NMR Spectra were recorded on a Gemini 200 or 300 apparatus with
CDCl3 as the solvent. FAB or MALDI-MS were registered on VG ZAB SEQ spectrometer.
Materials. The Me and allyl glycopyranosides 2 [36], 12 [41], 18 [45], 21 [46], 25 [47], 27 [48], 32 [49], 36
[49], 40 [50], 43 [50], 47 [51], and 49 [50] were prepared according to literature procedures. Commercial (Æ)-
trans-cyclohexane-1,2-diol (9) was purified by FC before use. The enantiomeric excess of (Æ)-trans-cyclohexane-
1,2-diol (ee < 0.5%) and (S,S)-trans-cyclohexane-1,2-diol (ee > 99.5%) was determined by chiral HPLC of the
corresponding dibenzoates (column and conditions: see below).
(S)-2-{[Benzyl(methyl)amino]methyl}-1-methylpyrrolidine [31] ((S)-1). A soln. of N-Boc-l-proline
(2.15 g, 10 mmol) and benzyl(methyl)amine (1.33 g, 11 mmol) in CH2Cl2 (45 ml) was treated dropwise with a
soln. of dicyclohexylcarbodiimide (DCC, 2.27 g, 11 mmol) in CH2Cl2 (12 ml) at 08 and stirred at r.t. for 2 h, when
a white precipitate was formed. After stirring for additional 48 h and evaporation, a suspension of the residue in
Et2O (30 ml) was filtered. Evaporation of the filterate and FC (column conditioned with hexane/Et3N 99.5 :0.5
and eluted with hexane/AcOEt 1 :3) gave tert-butyl (S)-2-[(benzylmethyl)carbamoyl]pyrrolidine-1-carboxylate
[59] (2.09 g, 65%). At 08, a soln. of this amide (1.59 g, 5 mmol) in THF (35 ml) was treated dropwise with a
suspension of LiAlH4 (0.8 g, 21 mmol) in THF (20 ml) and stirred at 08 for 1 h, at r.t. for 1 h, at reflux overnight,
cooled to 08, and treated with sat. aq. Na2SO4 soln. until gas evolution ceased. After extraction with Et2O (3 Â
40 ml), the combined org. phases were dried (MgSO4) and evaporated. FC (CH2Cl2/MeOH/Et3N 20 :1:0.5) of
the colourless oily residue gave (S)-18) (0.92 g, 82%). A faint yellow oil. Rf (CH2Cl2/MeOH/Et3N 100 :5 :3) 0.45.
[a]2D5 ˆ À101.8 (c ˆ 0.55, CHCl3). 1H-NMR (200 MHz, CDCl3): 7.4 7.2 ( m, 5 H); 3.59 (d, J ˆ 13.0, PhCH); 3.44
(d, J ˆ 13.0, PhCH); 3.04 (ddd, J ˆ 9.0, 6.8, 2.2, HÀC(2)); 2.62 2.50 (m, 1 H); 2.40 (s, MeN); 2.4 2.25 (m,
2 H); 2.22 (s, MeN); 2.18 (dd, J ˆ 17.0, 9.2, 1 H); 2.1 1.9 (m, 1 H); 1.85 1.5 (m, 3 H). 13C NMR (50 MHz,
CDCl3): 139.2 (s); 128.9 (2d); 128.1 (2d); 126.8 (d); 63.7 (t, PhCH2); 63.1 (d, C(2)); 62.6 (t, CH2ÀC(2)); 57.7 (t,
C(5)); 43.0 (q, MeN); 41.3( q, MeN); 30.7 (t, C(3)); 22.4 (t, C(4)).
(R)-2-{[Benzyl(methyl)amino]methyl}-1-methylpyrrolidine ((R)-1). Similar to the preparation of (S)-1,
treatment of N-Boc-d-proline (215 mg, 1.0 mmol) and benzyl(methyl)amine (133 mg, 1.1 mmol) in CH2Cl2
(5 ml) with DCC (227 mg, 1.1 mmol) in CH2Cl2 (1 ml) afforded tert-butyl (R)-2-[(benzylmethyl)carbamoyl]-
pyrrolidine-1-carboxylate (212 mg, 67.3%), and the hydrogenation of this amide (132 mg) with LiAlH4 (67 mg,
1.76 mmol) gave (R)-18) (77 mg, 85%). [a]D25 ˆ ‡102.0 (c ˆ 0.55, CHCl3). 1H-NMR and 13C-NMR data were
identical to those of (R)-1.
General Procedure for Benzoylation. Under Ar, a suspension of the substrate (0.25 mmol) and 4-ä
molecular sieves (500 mg) in CH2Cl2 (7 ml) was treated with (S)-1, (R)-1, TMEDA, TEEDA, or EtNMe2 (2.5 to
12.5 mmol, 1 to 5 mol-%, or as indicated in the Tables) in CH2Cl2 (1 ml) at r.t., cooled to À608, treated with Et3N
(28 mg, 0.25 mmol), EtNMe2 (19 mg, 0.25 mmol), or pyridine (20 mg, 0.25 mmol), and with BzCl (36 mg,
0.25 mmol), stirred for 1 h at À608, treated with phosphate buffer, pH 7 (5 ml), warmed to r.t., and extracted
with Et2O (15 ml). The org. phase was washed with brine (3 Â 10 ml), dried (MgSO4), and evaporated.
Benzoylation of 2. According to the General Procedure and to Tables 1, 2, and 5. The products were isolated
by FC (cyclohexane/AcOEt 8 :1 ! 1:2).
Methyl 2-O-Benzoyl-6-O-[(tert-butyl)diphenylsilyl]-b-d-glucopyranoside (3). White solid. Rf (hexane/
AcOEt 2 :1) 0.38. [a]2D5 ˆ À31.0 (c ˆ 0.5, CHCl3). IR (CHCl3): 3601w, 3500w, 3072w, 3008m, 2932m, 2888m,
2859m, 1727s, 1602w, 1451m, 1428m, 1392w, 1316m, 1270s, 1114s, 1070s, 1028m, 980w, 823m. 1H-NMR
(300 MHz, CDCl3): 8.15 8.05 (m, 2 arom. H); 7.80 7.65 (m, 4 arom. H); 7.60 7.50 (m, 1 arom. H); 7.50 7.35
(m, 8 arom. H); 5.08 4.98 (m, irrad. at 4.51 ! change, HÀC(2)); 4.51 (d, J ˆ 7.8, irrad. at 5.04 ! change,
HÀC(1)); 3.97 (d, J ˆ 4.6, 2 HÀC(6)); 3.86 3.70 (AB, J ꢀ 7.8, HÀC(3), HÀC(4)); 3.49 (dt, J ˆ 9.3, 4.6,
HÀC(5)); 3.47 (s, MeO); 3.16 (br. s, exchange with D2O, HOÀC(4)); 2.79 (br. s, exchange with D2O,
HOÀC(3)); 1.07 (s, Me3C). 13C-NMR (50 MHz, CDCl3): 166.6 (s, CˆO); 135.83 (2d of PhSi); 135.76 (2d of
PhSi); 133.5 (d of Bz); 133.1, 132.9 (2s of PhSi); 130.1, 130.06 (2d of Bz, 2d of PhSi); 129.8 (s of Bz); 128.5 (2d of
Bz); 128.0, 127.97 (4d of PhSi); 56.8 (q, MeO); 26.9 (q, Me3C); 19.4 (s, Me3C); data for C(1) C(6), see Table 8.
8
)
The enantiomer purity of (S)-1 and (R)-1 was determined by HPLC. (Chiralpak AD; hexane/Et2NH
100:0.01, 0.5 ml/min). A single peak was observed for each diamine; tR 9.6 ((R)-1) and 11.0 min ((S)-1).

Helvetica Chimica Acta Vol. 86 (2003)
4383
C(6)
Table 8. Selected 13C-NMR Chemical Shifts [ppm] of C(1) C(6) of Some Benzoatesa)
Compound
C(1)
C(2)
C(3)
C(4)
C(5)
b
3
4
5
6
7
101.7
103.5
103.5
102.0
104.0
99.5
99.0
97.1
97.2
104.1
97.5
99.8
100.369.1
98.7
100.6
98.8
98.7
100.2
101.5
96.1
98.1
99.6
75.8
72.3
74.3
71.6
72.9
71.2b)
71.9
71.8
74.5
70.0
72.4
67.4
74.6b)
78.7
75.1
76.9
75.9
77.6
73.3
74.1
70.9
73.2
68.7
74.2
72.8
70.6
75.1
71.2
75.2
70.5
73.7
71.0
72.5
72.3
69.370.1
68.9
75.2
71.4
71.7
74.8
75.3
71.7
75.6
69.0
)
64.7
64.3
63.0
64.4
63.0
64.4
64.4
14
15
16
17
20
22
23
26
28
29
30
31
33
34
39
46
52
71.5b)
70.7
71.364.3
70.2
64.3
61.6
73.9
.6
63
69.6
63.7
76.4
67.2
70.4
67.6
70.7
64.7
72.369.4
69.375.1
72.373 67.7
73.2
74.8
73.5
64.1
64.6
.1
64.2
70.5
72.4
74.3
69.1
71.0
80.9
78.6
72.5
74.362.3 69.2
76.8
69.7
66.2
66.4
63.0
64.2
68.6
68.6
79.6
69.0
69.3b)
70.9
68.9b)
69.0b)
)
b
63.8
68.9b)
a) The assignment of signals are based on [11] and [60]. b) The assignments may be interchanged.
Methyl 3-O-Benzoyl-6-O-[(tert-butyl)diphenylsilyl]-b-d-glucopyranoside (4). White solid. Rf (hexane/
AcOEt 2 :1) 0.45. [a]2D5 ˆ À10.0 (c ˆ 0.5, CHCl3). IR (CHCl3): 3603m, 3498m, 3069w, 2935m, 2889m, 2860m,
1
1719s, 1587w, 1451m, 1427m, 1391m, 1274s, 1114s, 1068s, 93 6w, 818m. H-NMR (200 MHz, CDCl3): 8.12 8.05
(m, 2 arom. H); 7.74 7.65 (m, 4 arom. H); 7.56 7.3( m, 9 arom. H); 5.21 (t, J ˆ 9.1, HÀC(3)); 4.31 (d, J ˆ 7.5,
HÀC(1)); 3.97 (d, J ˆ 5.0, 2 HÀC(6)); 3.87 (td, J ˆ 9.1, 3.3, irrad. at 5.21 ! change, irrad. at 3.21 ! t, J ˆ 9.5,
addition of D2O ! t, J ˆ 9.1, HÀC(4)); 3.62 (ddd, J ˆ 9.5, 7.5, 2.9, irrad. at 5.21 ! change, irrad. at 4.31 !
change, irrad. at 2.79 ! dd, J ˆ 9.5, 7.9, addition of D2O ! dd, J ˆ 9.5, 7.9, HÀC(2)); 3.53 (s, MeO); 3.50 (dt, J ˆ
9.1, 4.5, HÀC(5)); 3.21 (d, J ˆ 3.3, exchange with D2O, HOÀC(4)); 2.79 (d, J ˆ 2.9, exchange with D2O,
HOÀC(2)); 1.05 (s, Me3C). 13C-NMR (50 MHz, CDCl3): 167.6 (s, CˆO); 135.6 (2d of PhSi); 135.5 (2d of PhSi);
133.3 (d of Bz); 133.0, 132.9 (2s of PhSi); 129.9, 129.8 (2d of Bz, 2d of PhSi); 129.5 (s of Bz); 128.3(2 d of Bz);
127.7 (4d of PhSi); 57.0 (q, MeO); 26.7 (q, Me3C); 19.1 (s, Me3C); for data of C(1) C(6), see Table 8. FAB-MS:
‡
‡
‡
1095 (5, [2M ‡ Na] ), 559 (37, [M ‡ Na] ), 537 (54, [M ‡ H] ). Anal. calc. for C30H36O7Si (536.70): C 67.14, H
6.76; found: C 66.94, H 6.85.
Methyl 4-O-Benzoyl-6-O-[(tert-butyl)diphenylsilyl]-b-d-glucopyranoside (5). White solid. Rf (hexane/
AcOEt 2 :1) 0.1. [a]D25 ˆ ‡5.8 (c ˆ 0.5, CHCl3). IR (CHCl3): 3603w, 3439w (br.), 3072w, 3008m, 2932m, 2880w,
2858m, 1725s, 1602w, 1472w, 1451m, 1428m, 1392w, 1316m, 1270s, 1114vs, 1069s, 1046s, 982w, 823w. 1H-NMR
(300 MHz, CDCl3): 8.0 7.9 (m, 2 arom. H); 7.72 7.64 (m, 2 arom. H); 7.62 7.54 (m, 3arom. H); 7.47 7.16 ( m,
8 arom. H); 5.22 (t, J ˆ 9.3, irrad. at 3.81 ! d, J ˆ 8.8, irrad. at 3.65 ! d, J ˆ 10.3, HÀC(4)); 4.29 (d, J ˆ 7.5, irrad.
at 3.55 ! s, HÀC(1)); 3.83 (d, J ˆ 3.4, irrad. at 3.65 ! s, 2 HÀC(6)); 3.81 (t, J ˆ 9.4, irrad. at 5.22 ! change,
HÀC(3)); 3.65 (dt, J ˆ 9.6, 3.0, irrad. at 5.22 ! br. t, J ˆ 3.1, HÀC(5)); 3.59 (s, MeO); 3.55 (dd, J ˆ 9.3, 8.0,
addition of D2O ! change, irrad. at 4.29 ! d, J ˆ 9.5, HÀC(2)); 3.29 (br. s, exchange with D2O, HOÀC(3)); 3.20
(br. s, exchange with D2O, HOÀC(2)); 1.00 (s, Me3C). 13C-NMR (75 MHz, CDCl3): 166.0 (s, CˆO); 135.8 (2d of
PhSi); 135.7 (2d of PhSi); 133.6 (d of Bz); 133.4 (2s of PhSi); 130.0, 129.8, 129.77 (2d of Bz, 2d of PhSi); 129.7 (s
of Bz); 128.6 (2d of Bz); 127.8 (4d of PhSi); 56.9 (q, MeO); 26.6 (q, Me3C); 19.1 (s, Me3C); for data of C(1)
C(6), see Table 8.
Methyl 2,3-Di-O-benzoyl-6-O-[(tert-butyl )diphenylsilyl]-b-d-glucopyranoside (6). White solid. Rf (hex-
ane/AcOEt 3:1) 0.34. [ a]2D5 ˆ ‡64.6 (c ˆ 0.1, CHCl3). IR (CHCl3): 3608m, 3443w, 3008m, 2932w, 2858w, 1729s,

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Helvetica Chimica Acta Vol. 86 (2003)
1602m, 1451w, 1428w, 1279s, 1112s, 1070m, 93 1w. 1H-NMR (300 MHz, CDCl3): 8.05 7.90 (m, 4 arom. H); 7.76
7.70 (m, 4 arom. H); 7.54 7.34 (m, 12 arom. H); 5.49 (t, J ˆ 10.0, HÀC(3)); 5.40 (dd, J ˆ 10.0, 7.8, irrad. at
4.61 ! d, J ˆ 9.6, HÀC(2)); 4.61 (d, J ˆ 7.5, HÀC(1)); 4.03( td, J ˆ 9.2, 3.4, irrad. at 3.62 ! change, irrad. at
3.23 ! t, J ˆ 9.2, addition of D2O ! t, J ˆ 9.2, HÀC(4)); 4.03( d, J ˆ 4.7, irrad. at 3.62 ! s, 2 HÀC(6)); 3.62 (dt,
J ˆ 9.6, 4.6, HÀC(5)); 3.50 (s, MeO); 3.23 (d, J ˆ 3.4, exchange with D2O, HOÀC(4)); 1.09 (s, Me3C). 13C-NMR
(75 MHz, CDCl3): 167.5, 165.7 (2s, 2 CˆO); 136.0 (2d of PhSi); 135.9 (2d of PhSi); 133.6, 133.4 (2d of Bz); 133.3,
133.1 (2s of PhSi); 130.2, 130.1, 130.0 (2d of PhSi, 4d of Bz); 129.7, 129.4 (2s of Bz); 128.63, 128.57 (4d of Bz);
128.07, 128.03(4 d of PhSi); 56.9 (q, MeO); 26.9 (q, Me3C); 19.3( s, Me3C); for data of C(1) C(6), see Table 8.
‡
MALDI-MS: 663([ M ‡ Na] ). Anal. calc. for C37H40O8Si (640.80): C 69.35, H 6.29; found: C 69.27, H 6.34.
Methyl 3,4-Di-O-benzoyl-6-O-[(tert-butyl)diphenylsilyl]-b-d-glucopyranoside (7). White solid. Rf (hexane/
AcOEt 2 :1) 0.49. [a]2D5 ˆ À60.0 (c ˆ 0.5, CHCl3). IR (CHCl3): 3606w, 3439w (br.), 3008m, 2932w, 2858w, 1729s,
1
1602m, 1451m, 1428w, 1316w, 1277s, 1113s, 1069m, 1027m, 93 1w. H-NMR (300 MHz, CDCl3): 8.0 7.94 (m, 2
arom. H); 7.88 7.82 (m, 2 arom. H); 7.72 7.65 (m, 2 arom. H); 7.63 7.56 ( m, 2 arom. H); 7.55 7.44 (m, 2 arom.
H); 7.40 7.18 (m, 10 arom. H); 5.65 5.49 (AB, J ꢀ 9.0, HÀC(3), HÀC(4)); 4.45 (d, J ˆ 7.8, HÀC(1)); 3.84
3.72 (m, addition of D2O ! change, irrad. at 5.53 ! change, irrad. at 4.45 ! change, HÀC(2), HÀC(5); 2
HÀC(6)); 3.63 (s, MeO); 2.74 (d, J ˆ 3.1, exchange with D2O, HOÀC(2)); 1.03( s, Me3C). 13C-NMR (75 MHz,
CDCl3): 167.1, 165.5 (2s, 2 CˆO); 135.9 (2d of PhSi); 135.8 (2d of PhSi); 133.5, 133.44 (2d of Bz); 133.38 (2s of
PhSi); 130.2, 130.0, 129.88, 129.84 (2d of PhSi, 4d of Bz); 129.5 (2s of Bz); 128.6 (4d of Bz); 127.8 (4d of PhSi);
57.2 (q, MeO); 26.7 (q, Me3C); 19.2 (s, Me3C); for data of C(1) C(6), see Table 8.
Benzoylation of (1S,2S)-9. According to the General Procedure, treatment of (1S,2S)-9 (58 mg, 0.5 mmol)
with Et3N (56 mg), BzCl (72 mg, 0.5 mmol), and (S)-1 (5.4 mg) at À608 for 24 h followed by FC (hexane/
AcOEt 4 :1) gave (1S,2S)-10 (80 mg, 73%) and (1S,2S)-11 (18 mg, 11%).
Data of (1S,2S)-2-(benzoyloxy)cyclohexanol (10): White crystals. M.p. 115.5 116.58. [a]2D5 ˆ ‡55.0 (c ˆ 0.5,
CHCl3).
Data of (1S,2S)-cyclohexane-1,2-diyl Dibenzoate (11): White solid. [a]2D5 ˆ ‡97.4 (c ˆ 0.925, CHCl3).
Benzoylation of ( Æ )-9. According to the General Procedure, (Æ)-9 with (S)-1 or (R)-1 at À608 for 24 h and
FC (hexane/AcOEt 4 :1) gave 10 and 11 (see Table 3). The enantiomer purity of 10 and 11 was determined by
chiral HPLC (Chiralpak AS; solvent A (dibenzoate): hexane/i-PrOH 98 :2, 0.8 ml/min, tR 7.8 (( S,S)-11) and
8.9 min ((R,R)-11); solvent B (monobenzoate): hexane/i-PrOH 90 :10, 1.0 ml/min, tR 7.1 (( S,S)-10) and 14.7 min
((R,R)-10).
Benzoylation of 12. According to the General Procedure: a) 12 (216 mg, 0.5 mmol) with (S)-1 (5 mol-%)
followed by FC (cyclohexane/AcOEt 6 :1 ! 1 :2) gave 16/179) 89 :11 (11 mg, 3.5%), 14 (19 mg, 7%), and 13 [42]
(220 mg, 82%).
b) 12 (216 mg, 0.5 mmol) with (R)-1 (5 mol-%) followed by FC (cyclohexane/AcOEt 6 :1 ! 1 :2) gave 16/
17 63:37 (60 mg, 19%), 14 (75 mg, 28%), 13 (30 mg, 11%), 15 (27 mg, 10%), and 12 (40 mg, 18.5%).
c) 12 (216 mg, 0.5 mmol) with TMEDA (5 mol-%) followed by FC (cyclohexane/AcOEt 6 :1 ! 1 :2) gave
16/17 75 :25 (55 mg, 17%), 14 (9 mg, 3.5%), 13 (172 mg, 64%).
The mixture 16/17 from b was separated by HPLC (hexane/AcOEt 5 :1), yielding 35 mg of 16 and 21 mg of
17.
Methyl 3-O-Benzoyl-6-O-[(tert-butyl)diphenylsilyl]-a-d-glucopyranoside (14). White solid. Rf (cyclohex-
ane/AcOEt 2 :1) 0.48. [a]2D5 ˆ ‡72.8 (c ˆ 0.5, CHCl3). IR (CHCl3): 3568w, 3072w, 3008m, 2932m, 2859m, 1718s,
1602m, 1472w, 1452w, 1428m, 1316m, 1273s, 1113s, 1071m, 1059m, 998w, 823w. 1H-NMR (300 MHz, CDCl3):
8.13 8.08 ( m, 2 arom. H); 7.75 7.65 (m, 4 arom. H); 7.62 7.54 (m, 1 arom. H); 7.50 7.35 (m, 8 arom. H); 5.33
(t, J ˆ 9.3, HÀC(3)); 4.81 (d, J ˆ 3.7, HÀC(1)); 3.94 (d, J ˆ 4.4, 2 HÀC(6)); 3.81 (td, J ꢀ 9.3, 3.7, irrad. at 2.78 ! t,
J ˆ 9.3, addition of D2O ! t, J ˆ 9.5, addition of D2O and irrad. at 5.33 ! d, J ˆ 9.3, HÀC(4)); 3.75 (dt, J ꢀ 9.5,
3.2, HÀC(5)); 3.74 (ddd, J ꢀ 11.0, 10.0, 3.7, irrad. at 2.20 ! change, addition of D2O ! dd, J ˆ 10.0, 3.7, addition
of D2O and irrad. at 5.33 ! change, addition of D2O and irrad. at 4.81 ! d, J ˆ 9.7, HÀC(2)); 3.43 (s, MeO); 2.78
(d, J ˆ 3.3, exchange with D2O, HOÀC(4)); 2.20 (d, J ˆ 11.2, exchange with D2O, HOÀC(2)); 1.08 (s, Me3C).
13C-NMR (75 MHz, CDCl3): 168.2 (s, CˆO); 135.9 (4d of PhSi); 133.6 (d of Bz); 133.41, 133.36 (2s of PhSi);
130.2, 130.1 (2d of Bz, 2d of PhSi); 130.0 (s of Bz); 128.6 (2d of Bz); 128.0 (4d of PhSi); 55.4 (q, MeO); 26.9 (q,
Me3C); 19.3( s, Me3C); for data of C(1) C(6), see Table 8.
Methyl 4-O-Benzoyl-6-O-[(tert-butyl)diphenylsilyl]-a-d-glucopyranoside (15). White solid. Rf (cyclohex-
ane/AcOEt 2 :1) 0.11. [a]2D5 ˆ ‡94.6 (c ˆ 0.5, CHCl3). IR (CHCl3): 3570w, 3008m, 2932m, 2859m, 1724s, 1602w,
1
9
)
The ratio 16/17 was assigned by the integration of H-NMR signal of MeO.

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1472w, 1452w, 1428m, 1316m, 1269s, 1113s, 1075s, 1063s, 1026m, 977w, 823w. 1H-NMR (300 MHz, CDCl3): 8.0
7.94 (m, 2 arom. H); 7.68 7.52 (m, 5 arom. H); 7.48 7.40 (m, 2 arom. H); 7.38 7.25 (m, 4 arom. H); 7.22 7.14
(m, 2 arom. H); 5.17 (dd, J ˆ 9.9, 9.3, HÀC(4)); 4.88 (d, J ˆ 3.7, HÀC(1)); 3.98 (t, J ˆ 9.3, irrad. at 5.17 ! change,
irrad. at 3.70 ! d, J ˆ 9.3, HÀC(3)); 3.96 (ddd, J ˆ 9.9, 4.4, 2.8, irrad. at 5.17 ! change, HÀC(5)); 3.81 (dd, J ˆ
11.2, 4.4, HÀC(6)); 3.77 (dd, J ˆ 11.2, 2.8, H'ÀC(6)); 3.70 (dd, J ˆ 9.3, 3.7, irrad. at 4.88 ! d, J ˆ 9.3, HÀC(2));
3.49 (s, MeO); 2.78 (br. s, exchange with D2O, HOÀC(3)); 2.30 (br. s, exchange with D2O, HOÀC(2)); 1.01 (s,
Me3C). 13C-NMR (75 MHz, CDCl3): 166.5 (s, CˆO); 135.6, 135.5 (4d of PhSi); 133.4 (d of Bz); 133.15, 133.09
(2s of PhSi); 130.0 (2d of Bz); 129.6 (2d of PhSi); 129.5 (s of Bz); 128.5 (2d of Bz); 127.67, 127.63(4 d of PhSi);
55.6 (q, MeO); 26.9 (q, Me3C); 19.3( s, Me3C); for data of C(1) C(6), see Table 8.
Methyl 2,3-Di-O-benzoyl-6-O-[(tert-butyl)diphenylsilyl]-a-d-glucopyranoside (16). White solid. Rf (hex-
ane/AcOEt 2 :1) 0.60. [a]2D5 ˆ ‡107.2 (c ˆ 0.5, CHCl3). IR (CHCl3): 3509w, 3071w, 3008m, 2932m, 2859m, 1723s,
1602m, 1472m, 1452m, 1428m, 1316m, 1280s, 1112s, 1070s, 1054s, 997m, 823m. 1H-NMR (300 MHz, CDCl3):
8.05 7.95 (m, 4 arom. H); 7.9 7.83( m, 4 arom. H); 7.6 7.28 (m, 12 arom. H); 5.77 (dd, J ˆ 10.2, 9.0, irrad. at
5.21 ! change, irrad. at 3.95 ! d, J ˆ 10.2, HÀC(3)); 5.21 (dd, J ˆ 10.2, 3.7, irrad. at 5.77 ! change, irrad. at
5.10 ! change, HÀC(2)); 5.10 (d, J ˆ 3.7, irrad. at 5.21 ! s, HÀC(1)); 3.99 (d, J ˆ 4.4, 2 HÀC(6)); 3.95 (td, J ˆ
9.0, 3.7, addition of D2O ! change, irrad. at 5.77 ! change, irrad. at 2.97 ! change, HÀC(4)); 3.86 (dt, J ˆ 9.3,
4.4, HÀC(5)); 3.39 (s, MeO); 2.97 (d, J ˆ 3.7, exchange with D2O, HOÀC(4)); 1.09 (s, Me3C). 13C-NMR
(75 MHz, CDCl3): 167.5, 166.4 (2s, 2 CˆO); 135.94, 135.90 (4d of PhSi); 133.5 (2d of Bz); 133.4, 133.3 (2s of
PhSi); 130.1 (4d of Bz, 2d of PhSi); 129.7, 129.5 (2s of Bz); 128.64, 128.6 (4d of Bz); 128.0 (4d of PhSi); 55.3( q,
MeO); 26.9 (q, Me3C); 19.3( s, Me3C); for data of C(1) C(6), see Table 8.
Methyl 2,4-Di-O-benzoyl-6-O-[(tert-butyl)diphenylsilyl]-a-d-glucopyranoside (17). White solid. Rf (hex-
ane/AcOEt 2 :1) 0.56. [a]2D5 ˆ ‡93.0 (c ˆ 0.5, CHCl3). IR (CHCl3): 3611w, 3072w, 3008m, 2932m, 2859w, 1722s,
1602w, 1472w, 1452m, 1428m, 1316m, 1271s, 1112s, 1070m, 1043s, 969w, 823w. 1H-NMR (300 MHz, CDCl3):
8.14 8.08 (m, 2 arom. H); 8.02 7.95 (m, 2 arom. H); 7.69 7.53( m, 6 arom. H); 7.50 7.41 (m, 4 arom. H); 7.40
7.28 (m, 4 arom. H); 7.23 7.15 ( m, 2 arom. H); 5.31 (t, J ˆ 9.5, irrad. at 4.38 ! d, J ˆ 9.3, irrad. at 4.05 ! d, J ˆ
9.0, HÀC(4)); 5.13( d, J ˆ 3.7, HÀC(1)); 5.09 (dd, J ˆ 9.3, 3.7, HÀC(2)); 4.38 (td, J ˆ 9.3, 5.6, addition of D2O !
t, J ˆ 9.3, addition of D2O and irrad. at 5.31 ! d, J ˆ 9.7, HÀC(3)); 4.05 (ddd, J ˆ 10.0, 4.4, 2.5, HÀC(5)); 3.85
(dd, J ˆ 11.5, 4.4, HÀC(6)); 3.81 (dd, J ˆ 11.5, 2.5, H'ÀC(6)); 3.44 (s, MeO); 2.70 (d, J ˆ 5.6, exchange with D2O,
HOÀC(3)); 1.01 (s, Me3C). 13C-NMR (75 MHz, CDCl3): 166.8, 166.5 (2s, 2 CˆO); 135.8, 135.7 (4d of PhSi);
133.6, 133.5 (2d of Bz); 133.25, 133.2 (2s of PhSi); 130.15, 130.12, 129.8 (4d of Bz, 2d of PhSi); 129.5 (2s of Bz);
128.6 (4d of Bz); 127.8, 127.76 (4d of PhSi); 55.3( q, MeO); 26.9 (q, Me3C); 19.3( s, Me3C); for data of C(1)
C(6), see Table 8.
Benzoylation of 18. According to the General Procedure: a) Due to the insolubility of 18 in CH2Cl2 at À608,
the reaction of 18 (108 mg, 0.25 mmol) with (S)-1 (5 mol-%) was run at À58. FC (cyclohexane/AcOEt 6 :1 !
1
1:2) gave a mixture of dibenzoates (from H-NMR) (20 mg), 19 [61] (91 mg, 68%), and 18 (8 mg, 7%).
b) 18 (108 mg, 0.25 mmol) with (R)-1 (5 mol-%) at À58 followed by FC (cyclohexane/AcOEt 6 :1 ! 1:2)
gave a mixture of dibenzoates (11 mg), 19 (82 mg, 61%), 20 (8 mg, 6%), and 18 (10 mg, 9%).
c) 18 (108 mg, 0.25 mmol) with TMEDA (5 mol-%) at À58 followed by FC (cyclohexane/AcOEt 6 :1 !
1:2), gave a mixture of dibenzoates (23mg), 19 (75 mg, 56%), 20 (5 mg, 4%), and 18 (12 mg, 11%).
Methyl 4-O-Benzoyl-6-O-[(tert-butyl)diphenylsilyl]-b-d-galactopyranoside (20). White solid. Rf (cyclo-
hexane/AcOEt 2 :1) 0.10. [a]2D6 ˆ À22.6 (c ˆ 0.58, CHCl3). IR (CHCl3): 3598m, 3436w, 3008m, 2961m, 2932m,
2888w, 2859m, 1722s, 1602w, 1451m, 1428m, 1316w, 1275s, 1113s, 1071s, 825m. 1H-NMR (300 MHz, CDCl3):
8.1 8.02 (m, 2 arom. H); 7.66 7.55 (m, 3arom. H); 7.5 7.22 ( m, 8 arom. H); 7.14 7.05 (m, 2 arom. H); 5.74 (d,
J ꢀ 3.0, HÀC(4)); 4.25 (d, J ˆ 7.8, HÀC(1)); 3.94 (dt, J ˆ 9.6, 3.1, addition of D2O ! dd, J ˆ 9.6, 3.4, HÀC(3));
3.87 3.75 (m, HÀC(5), 2 HÀC(6)); 3.72 (ddd, J ˆ 9.9, 8.1, 1.6, addition of D2O ! dd, J ˆ 10.0, 7.8, HÀC(2));
3.56 (s, MeO); 2.65, 2.49 (2 br. s, exchange with D2O, HOÀC(2), HOÀC(3)); 0.99 (s, Me3C). 13C-NMR
(75 MHz, CDCl3): 166.9 (s, CˆO); 135.6, 135.5 (4d of PhSi); 133.4 (d of Bz); 133.0, 132.7 (2s of PhSi); 130.1,
129.9, 129.7 (2d of Bz, 2d of PhSi); 129.6 (s of Bz); 128.5 (2d of Bz); 127.8, 127.7 (4d of PhSi); 57.6 (q, MeO); 26.9
‡
(q, Me3C); 19.3( s, Me3C); for data of C(1) C(6), see Table 8. MALDI-MS: 559 ([M ‡ Na] ).
Benzoylation of 21. According to the General Procedure: a) 21 (108 mg, 0.25 mmol) with (S)-1 (5 mol-%)
followed by FC (cyclohexane/AcOEt 6 :1 ! 2 :1) gave 24 [46] (4 mg, 3%), 22 (104 mg, 78%), and 23 (3mg,
2%).
b) 20 (108 mg, 0.25 mmol) with (R)-1 (5 mol-%) followed by FC (cyclohexane/AcOEt 6 :1 ! 2 :1) gave 24
(13mg, 8%), 22 (14 mg, 10%), and 23 (76 mg, 57%).
c) 20 (108 mg, 0.25 mmol) with TMEDA (5 mol-%) followed by FC (cyclohexane/AcOEt 6 :1 ! 2 :1) gave
24 (15 mg, 9%), 22 (93mg, 69%), and 23 (3mg, 2%).

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Methyl 2-O-Benzoyl-6-O-[(tert-butyl)diphenylsilyl]-a-d-galactopyranoside (22). White solid. Rf (hexane/
AcOEt 2 :1) 0.46. [a]2D5 ˆ ‡83.2 (c ˆ 0.5, CHCl3). IR (CHCl3): 3564m, 3470w, 2935s, 2894m, 2881m, 1718s,
1
1595w, 1453m, 1427m, 1332m, 1279s, 1108vs, 1043s, 822m. H-NMR (200 MHz, CDCl3): 8.1 8.05 (m, 2 arom.
H); 7.75 7.62 (m, 4 arom. H); 7.6 7.3( m, 9 arom. H); 5.23( dd, J ˆ 9.7, 3.7, HÀC(2)); 5.01 (d, J ˆ 3.7, HÀC(1));
4.20 (t, J ˆ 3.0, irrad. at 2.98 ! change, addition of D2O ! d, J ˆ 3.0, HÀC(4)); 4.11 (ddd, J ˆ 9.9, 8.3, 3.3, irrad.
at 2.63 ! dd, J ˆ 10.0, 3.3, addition of D2O ! dd, J ˆ 10.1, 3.3, HÀC(3)); 4.0 3.8 (m, HÀC(5), 2 HÀC(6)); 3.31
(s, MeO); 2.98 (d, J ˆ 2.9, exchange with D2O, HOÀC(4)); 2.63( d, J ˆ 8.3, exchange with D2O, HOÀC(3)); 1.06
(s, Me3C). 13C-NMR (50 MHz, CDCl3): 167.0 (s, CˆO); 135.9, 135.6 (4d of PhSi); 133.3 (d of Bz); 133.1, 133.0
(2s of PhSi); 129.9 (2d of Bz, 2d of PhSi); 129.6 (s of Bz); 128.4 (2d of Bz); 127.8 (4d of PhSi); 55.2 (q, MeO); 26.7
‡
(q, Me3C); 19.0 (s, Me3C); for data of C(1) C(6), see Table 8. FAB-MS: 1095 (4, [2M ‡ Na] ), 1073(7, [2 M ‡
‡
‡
‡
H] ), 559 (16, [M ‡ Na] ), 537 (14, [M ‡ H] ), 505 (100). Anal. calc. for C30H36O7Si (536.70): C 67.14, H 6.76;
found: C 66.92, H 6.86.
Methyl 3-O-Benzoyl-6-O-[(tert-butyl)diphenylsilyl]-a-d-galactopyranoside (23). White solid. Rf (hexane/
AcOEt 2 :1) 0.27. [a]2D5 ˆ ‡99.6 (c ˆ 0.5, CHCl3). IR (CHCl3): 3567m, 3471w, 3069w, 2934m, 2861m, 1717s,
1601w, 1452m, 1427m, 1274s, 1108s, 1055s, 982w, 818m, 616w. 1H-NMR (200 MHz, CDCl3): 8.13 8.1 ( m, 2 arom.
H); 7.72 7.64 (m, 4 arom. H); 7.6 7.3( m, 9 arom. H); 5.26 (dd, J ˆ 10.2, 3.0, HÀC(3)); 4.87 (d, J ˆ 3.7,
HÀC(1)); 4.31 (t, J ˆ 3.0, addition of D2O ! d, J ˆ 3.0, HÀC(4)); 4.20 (td, J ˆ 10.4, 3.7, addition of D2O ! dd,
J ˆ 10.4, 3.7, HÀC(2)); 3.95 3.84 (m, HÀC(5), 2 HÀC(6)); 3.39 (s, MeO); 2.70 (d, J ˆ 3.3, exchange with D2O,
HOÀC(4)); 2.00 (d, J ˆ 11.2, exchange with D2O, HOÀC(2)); 1.04 (s, Me3C). 13C-NMR (50 MHz, CDCl3):
166.6 (s, CˆO); 135.7, 135.6 (4d of PhSi); 133.3 (d of Bz); 133.0, 132.8 (2s of PhSi); 130.0 (2d of Bz, 2d of PhSi);
129.9 (s of Bz); 128.5 (2d of Bz); 127.8 (4d of PhSi); 55.3( q, MeO); 26.7 (q, Me3C); 19.1 (s, Me3C); for data of
‡
‡
‡
C(1) C(6), see Table 8. FAB-MS: 1073(10, [2 M ‡ H] ), 559 (15, [M ‡ Na] ), 537 (47, [M ‡ H] ), 427 (100).
Anal. calc. for C30H36O7Si (536.70): C 67.14, H 6.76; found: C 67.03, H 6.91.
Benzoylation of 25. According to the General Procedure: a) 25 (108 mg, 0.25 mmol) with (S)-1 (5 mol-%)
followed by FC (hexane/AcOEt 2 :1) gave 26 (115 mg, 86%).
b) 25 (108 mg, 0.25 mmol) with (R)-1 (5 mol-%) followed by FC (hexane/AcOEt 2 :1) gave 26 (84 mg,
63%) and 25 (7 mg, 6.5%).
Methyl 3-O-Benzoyl-6-O-[(tert-butyl)diphenylsilyl]-b-d-mannopyranoside (26). White solid. Rf (hexane/
AcOEt 2 :1) 0.6. [a]2D5 ˆ À51.2 (c ˆ 0.5, CHCl3). IR (CHCl3): 3577m, 3507m, 3069w, 3008m, 2935m, 2860m,
1718s, 1601w, 1452m, 1427m, 1368m, 1275s, 1111s, 1070s, 1002m, 93 6w, 880w, 818m. 1H-NMR (200 MHz, CDCl3):
8.2 8.0 (m, 2 arom. H); 7.8 7.6 (m, 4 arom. H); 7.6 7.3( m, 9 arom. H); 5.06 (dd, J ˆ 9.5, 2.9, HÀC(3)); 4.51 (d,
J ˆ 0.8, HÀC(1)); 4.27 (td, J ˆ 9.5, 2.9, irrad. at 5.06 ! change, irrad. at 3.45 ! change, irrad. at 2.90 ! t, J ˆ 9.5,
addition of D2O ! t, J ˆ 9.5, HÀC(4)); 4.21 (td, J ˆ 2.9, 0.8, irrad. at 5.06 ! change, irrad. at 4.51 ! change,
irrad. at 2.18 ! change, addition of D2O ! br. d, J ꢀ 3.3, HÀC(2)); 3.99 (d, J ˆ 5.0, irrad. at 3.45 ! s, 2 HÀC(6));
3.52 (s, MeO); 3.45 (dt, J ˆ 9.5, 5.0, HÀC(5)); 2.90 (d, J ˆ 2.9, exchange with D2O, HOÀC(4)); 2.18 (d, J ˆ 2.9,
exchange with D2O, HOÀC(2)); 1.00 (s, Me3C). 13C-NMR (50 MHz, CDCl3): 166.6 (s, CˆO); 135.3, 135.2 (4d of
PhSi); 132.9 (d of Bz); 132.6, 132.5 (2s of PhSi); 129.6, 129.5 (2d of Bz, 2d of PhSi); 129.3( s of Bz); 128.0 (2d of
Bz); 127.4 (4d of PhSi); 56.8 (q, MeO); 26.7 (q, Me3C); 19.2 (s, Me3C); for data of C(1) C(6), see Table 8.
‡
MALDI-MS: 559 ([M ‡ Na] ). Anal. calc. for C30H36O7Si (536.70): C 67.14, H 6.76; found: C 67.08, H 6.90.
Benzoylation of 27. According to the General Procedure: a) 27 (108 mg, 0.25 mmol) with (S)-1 (5 mol-%)
followed by FC (cyclohexane/AcOEt 5 :1 ! 1:4) gave 29 [48] (115 mg, 86%) and 28 (11 mg, 8%).
b) 27 (108 mg, 0.25 mmol) with (R)-1 (5 mol-%) followed by FC (cyclohexane/AcOEt 5 :1 ! 1:4) gave 30
(10 mg, 6%), 31 (16 mg, 10%), 29 (13mg, 10%), and 28 (63mg, 47%).
c) 27 (108 mg, 0.25 mmol) with TMEDA (5 mol-%) followed by FC (cyclohexane/AcOEt 5 :1 ! 1:4) gave
30 (10 mg, 6%), 31 (5 mg, 3%), 29 (45 mg, 34%), 28 (16 mg, 12%), and 27 (11 mg, 10%).
Methyl 2-O-Benzoyl-6-O-[(tert-butyl)diphenylsilyl]-a-d-mannopyranoside (28). White solid. Rf (hexane/
AcOEt 2 :1) 0.30. [a]2D5 ˆ ‡8.0 (c ˆ 0.5, CHCl3). IR (CHCl3): 3591m, 3514w, 2932s, 2859m, 1720s, 1602m, 1452m,
1428m, 1317m, 1271s, 1138s, 1114s, 1074s, 971m, 908m, 823m. 1H-NMR (300 MHz, CDCl3): 8.1 8.0 (m, 2 arom.
H); 7.8 7.7 (m, 4 arom. H); 7.6 7.3( m, 9 arom. H); 5.35 (dd, J ˆ 2.8, 1.5, irrad. at 4.82 ! d, J ˆ 2.8, HÀC(2));
4.82 (d, J ˆ 1.7, irrad. at 5.35 ! s, HÀC(1)); 4.15 4.0 (m, irrad. at 3.67 ! change, irrad. at 2.68 ! change, irrad. at
2.28 ! change, addition of D2O ! change, HÀC(3), HÀC(4)); 4.0 3.8 (m, irrad. at 3.67 ! change, 2 HÀC(6));
3.67 (dt, J ˆ 8.4, 4.5, HÀC(5)); 3.35 (s, MeO); 2.68 (d, J ˆ 2.2, exchange with D2O, HOÀC(4)); 2.28 (d, J ˆ 4.7,
exchange with D2O, HOÀC(3)); 1.07 (s, Me3C). 13C-NMR (50 MHz, CDCl3): 166.3( s, CˆO); 135.7, 135.6 (4d of
PhSi); 133.4 (d of Bz); 133.1, 133.0 (2s of PhSi); 129.9 (2d of Bz, 2d of PhSi); 129.5 (s of Bz); 128.4 (2d of Bz);
127.4 (4d of PhSi); 55.0 (q, MeO); 26.8 (q, Me3C); 19.2 (s, Me3C); for data of C(1) C(6), see Table 8. FAB-MS:

Helvetica Chimica Acta Vol. 86 (2003)
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‡
‡
559 (10, [M ‡ Na] ), 537 (6, [M ‡ H] ), 505 (100). Anal. calc. for C30H36O7Si (536.70): C 67.14, H 6.76; found: C
67.22, H 6.86.
Methyl 3-O-Benzoyl-6-O-[(tert-butyl)diphenylsilyl]-a-d-mannopyranoside (29) [48]. White solid. Rf
1
(cyclohexane/AcOEt 2 :1) 0.43. [a]2D5 ˆ ‡25.5 (c ˆ 0.62, CHCl3). H-NMR (300 MHz, CDCl3): 8.14 8.06 (m,
2 arom. H); 7.76 7.66 (m, 4 arom. H); 7.62 7.54 (m, 1 arom. H); 7.50 7.35 (m, 8 arom. H); 5.34 (dd, J ˆ 9.7, 3.1,
HÀC(3)); 4.74 (d, J ˆ 1.6, HÀC(1)); 4.18 (td, J ꢀ 9.7, 3.4, addition of D2O ! t, J ˆ 9.6, HÀC(4)); 4.16 4.08 (m,
addition of D2O ! change, HÀC(2)); 4.04 3.92 (m, 2 HÀC(6)); 3.77 (dt, J ꢀ 9.6, 4.4, HÀC(5)); 3.38 (s, MeO);
2.81 (d, J ˆ 3.7, exchange with D2O, HOÀC(4)); 2.09 (d, J ˆ 6.2, exchange with D2O, HOÀC(2)); 1.08 (s, Me3C).
13C-NMR (75 MHz, CDCl3): 166.5 (s, CˆO); 135.6 (4d of PhSi); 133.3 (d of Bz); 132.9, 132.8 (2s of PhSi); 129.8
(2d of Bz, 2d of PhSi); 129.6 (s of Bz); 128.4 (2d of Bz); 127.7 (4d of PhSi); 55.0 (q, MeO); 27.0 (q, Me3C); 19.4 (s,
Me3C); for data of C(1) C(6), see Table 8.
Methyl 2,3-Di-O-benzoyl-6-O-[(tert-butyl)diphenylsilyl]-a-d-mannopyranoside (30). White solid. Rf
(cyclohexane/AcOEt 2 :1) 0.60. [a]2D6 ˆ À33.3 (c ˆ 0.85, CHCl3). IR (CHCl3): 3512w, 3072w, 3008w, 2932m,
2859w, 1725s, 1602m, 1452m, 1428m, 1316m, 1277s, 1138s, 1112s, 1078s, 1026m, 973w, 823m. 1H-NMR (300 MHz,
CDCl3): 8.12 8.04 (m, 2 arom. H); 7.98 7.90 (m, 2 arom. H); 7.82 7.70 (m, 4 arom. H); 7.64 7.30 (m, 12 arom.
H); 5.62 5.54 (m, HÀC(2), HÀC(3)); 4.89 (d, J ꢀ 1.2, HÀC(1)); 4.39 (br. t, J ꢀ 9.3, addition of D2O ! change,
HÀC(4)); 4.07 (dd, J ˆ 10.9, 4.0, HÀC(6)); 4.01 (dd, J ˆ 10.9, 4.0, H'ÀC(6)); 3.82 (dt, J ˆ 9.3, 4.0, HÀC(5)); 3.42
(s, MeO); 2.71 (br. s, exchange with D2O, HOÀC(4)); 1.10 (s, Me3C). 13C-NMR (75 MHz, CDCl3): 166.8, 165.8
(2s, 2 CˆO); 135.9, 135.8 (4d of PhSi); 133.6, 133.4 (2d of Bz); 133.3, 133.2 (2s of PhSi); 130.1 (4d of Bz, 2d of
PhSi); 129.8 (2s of Bz); 128.7 (2d of Bz); 128.5 (2d of Bz); 128.0, 127.9 (4d of PhSi); 55.2 (q, MeO); 27.0 (q,
‡
Me3C); 19.5 (s, Me3C); for data of C(1) C(6), see Table 8. MALDI-MS: 663([ M ‡ Na] ). Anal. calc. for
C37H40O8Si (640.80): C 69.35, H 6.29; found: C 69.44, H 6.30.
Methyl 2,4-Di-O-benzoyl-6-O-[(tert-butyl)diphenylsilyl]-a-d-mannopyranoside (31). White solid. Rf
(cyclohexane/AcOEt 2 :1) 0.55. [a]2D5 ˆ À17.0 (c ˆ 0.86, CHCl3). IR (CHCl3): 3570w (br.), 3072w, 3008m,
2932m, 2858w, 1721s, 1602w, 1452m, 1428m, 1316m, 1264s, 1113s, 1070s, 1028m, 983m, 823w. 1H-NMR
(300 MHz, CDCl3): 8.16 8.08 (m, 2 arom. H); 8.02 7.94 (m, 2 arom. H); 7.70 7.04 (m, 16 arom. H); 5.73( t, J ˆ
10.0, HÀC(4)); 5.39 (dd, J ˆ 3.4, 1.6, HÀC(2)); 4.95 (d, J ˆ 1.6, HÀC(1)); 4.38 4.26 (m, addition of D2O ! dd,
J ˆ 10.0, 3.4, HÀC(3)); 3.99 (ddd, J ˆ 10.0, 3.7, 1.9, HÀC(5)); 3.89 (dd, J ˆ 11.5, 4.0, HÀC(6)); 3.82 (dd, J ˆ 11.5,
1.9, H'ÀC(6)); 3.43 (s, MeO); 2.57 (br. d, J ˆ 7.5, exchange with D2O, HOÀC(3)); 1.00 (s, Me3C). 13C-NMR
(75 MHz, CDCl3): 167.3, 166.2 (2s, 2 CˆO); 135.8, 135.6 (4d of PhSi); 133.6 (2d of Bz); 133.1 (2s of PhSi); 130.2,
130.1, 129.8, 129.7 (4d of Bz, 2d of PhSi); 129.65, 129.6 (2s of Bz); 128.72 (2d of Bz); 128.67 (2d of Bz); 127.8,
127.7 (4d of PhSi); 55.4 (q, MeO); 26.8 (q, Me3C); 19.4 (s, Me3C); for data of C(1) C(6), see Table 8. MALDI-
‡
MS: 663([ M ‡ Na] ). Anal. calc. for C37H40O8Si (640.80): C 69.35, H 6.29; found: C 69.40, H 6.37.
Benzoylation of 32. According to the General Procedure: a) 32 (154 mg, 0.5 mmol) with BzCl (72 mg,
0.5 mmol) and (S)-1 (5.6 mg, 25 mmol) followed by FC (hexane/AcOEt 3:1) gave 35 [62] (12 mg, 5%), 33 [63]
(42 mg, 20%), and 34 (97 mg, 47%).
b) 32 (154 mg, 0.5 mmol) with BzCl (72 mg, 0.5 mmol) and (R)-1 (5.6 mg, 25 mmol) followed by FC
(hexane/AcOEt 3:1) gave 35 (22 mg, 9%), 33 (44 mg, 21%), and 34 (62 mg, 30%).
Allyl 2-O-Benzoyl-4,6-O-benzylidene-b-d-glucopyranoside (33) [63]. 1H-NMR (300 MHz, CDCl3): 8.12
8.04 (m, 2 arom. H); 7.63 7.34 ( m, 8 arom. H); 5.78 (dddd, J ˆ 17.1, 10.3, 6.2, 5.0, CHˆCH2); 5.58 (s, PhCH);
5.23( dq, J ˆ 17.1, 1.6, CHˆCH2); 5.22 (dd, J ˆ 9.3, 8.1, irrad. at 4.74 ! d, J ꢀ 8.4, HÀC(2)); 5.14 (dq, J ˆ 10.3,
1.2, CHˆCH2); 4.74 (d, J ˆ 8.1, HÀC(1)); 4.40 (dd, J ˆ 10.6, 5.0, HeqÀC(6)); 4.34 (ddt, J ˆ 13.4, 5.0, 1.6); 4.12
(ddt, J ˆ 13.1, 6.2, 1.2, OCH2CHˆCH2); 4.05 (td, J ˆ 9.6, 2.8, addition of D2O ! t, J ˆ 9.0, HÀC(3)); 3.85 (t, J ꢀ
10.0, HaxÀC(6)); 3.69 (t, J ꢀ 9.3, HÀC(4)); 3.53 (td, J ꢀ 10.0, 5.0, HÀC(5)); 2.78 (br. s, exchange with D2O,
HOÀC(3)). 13C-NMR (75 MHz, CDCl3): 165.7 (s, CˆO), 136.8 (s of PhCH); 133.24, 133.2 (d of Bz, d of
CHˆCH2); 129.8 (2d of Bz); 129.5 (s of Bz); 129.2 (d of PhCH); 128.3, 128.2 (2d of PhCH, 2d of Bz); 126.2 (2d
of PhCH); 117.7 (t, CHˆCH2); 101.8 (d, PhCH); 70.2 (t, OCH2CHˆCH2); for data of C(1) C(6), see Table 8.
Allyl 3-O-Benzoyl-4,6-O-benzylidene-b-d-glucopyranoside (34). White crystals. M.p. 165 166.58
(CH2Cl2). Rf (hexane/AcOEt 2 :1) 0.40. [a]D25 ˆ À92.0 (c ˆ 0.5, CHCl3). IR (CHCl3): 3597w, 3420w, 3038w,
2879m, 1727s, 1603w, 1453w, 1374m, 1314m, 1269s, 1098s, 1028s, 995s, 93 3w. 1H-NMR (300 MHz, CDCl3): 8.12
8.04 (m, 2 arom. H); 7.60 7.26 (m, 8 arom. H); 5.96 (dddd, J ˆ 17.0, 10.5, 6.5, 5.0, CHˆCH2); 5.53( s, PhCH);
5.49 (t, J ˆ 9.5, HÀC(3)); 5.35 (dq, J ˆ 17.4, 1.5), 5.23( dq, J ˆ 10.3, 1.5), (CHˆCH2); 4.60 (d, J ˆ 7.8, HÀC(1));
4.42 (ddt, J ˆ 12.8, 5.6, 1.5, OCH2CHˆCH2); 4.40 (dd, J ˆ 10.6, 5.0, irrad. at 3.60 ! d, J ˆ 9.4, HeqÀC(6)); 4.20
(ddt, J ˆ 12.8, 6.5, 1.5, OCH2CHˆCH2); 3.84 (t, J ˆ 10.6, irrad. at 4.40 ! d, J ˆ 10.0, irrad. at 3.60 ! change,
HaxÀC(6)); 3.82 (t, J ˆ 9.6, irrad. at 5.49 ! d, J ˆ 10.2, irrad. at 3.60 ! change, HÀC(4)); 3.76 (ddd, J ˆ 9.4, 7.5,
3.1, addition of D2O ! dd, J ˆ 9.4, 7.8, addition of D2O and irrad. at 5.49 ! d, J ˆ 7.2, addition of D2O and irrad.

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Helvetica Chimica Acta Vol. 86 (2003)
at 4.60 ! d, J ˆ 9.0, HÀC(2)); 3.60 (td, J ˆ 9.6, 5.0, irrad. at 4.40 ! t, J ˆ 10.0, HÀC(5)); 2.72 (d, J ˆ 3.1,
exchange with D2O, HOÀC(2)). 13C-NMR (50 MHz, CDCl3): 166.6 (s, CˆO), 136.9 (s of PhCH); 133.5 (d of
Bz); 133.3 (d, CHˆCH2); 130.0 (2d of Bz); 129.7 (s of Bz); 129.0 (d of PhCH); 128.4, 128.2 (2d of PhCH, 2d of
Bz); 126.1 (2d of PhCH); 118.4 (t, CHˆCH2); 102.6 (d, PhCH); 70.7 (t, OCH2CHˆCH2); for data of C(1)
‡
‡
C(6), see Table 8. FAB-MS: 825 (8, [2M ‡ H] ), 413(100, [ M ‡ H] ). Anal. calc. for C23H24O7 (412.44): C 66.98,
H 5.87; found: C 66.81, H 6.09.
Benzoylation of 36. According to the General Procedure: a) 36 (154 mg, 0.5 mmol) with BzCl (72 mg,
0.5 mmol) and (S)-1 (5.6 mg, 25 mmol) followed by FC (hexane/AcOEt 3:1) gave 37 [5] (172 mg, 83.5%) and 38
[49] (7 mg, 3%).
b) 36 (154 mg, 0.5 mmol) with BzCl (72 mg, 0.5 mmol) and (R)-1 (5.6 mg, 25 mmol) followed by FC
(hexane/AcOEt 3:1) gave 39 [49] (5 mg, 2%), 37 (167 mg, 81%), and 38 (19 mg, 9%).
Allyl 2,3-Di-O-benzoyl-4,6-O-benzylidene-a-d-glucopyranoside (39) [49]. White crystals. Rf (hexane/
AcOEt 2 :1) 0.57. 1H-NMR (300 MHz, CDCl3): 8.02 7.95 (m, 4 arom. H); 7.56 7.28 (m, 11 arom. H); 6.09 (t,
J ˆ 9.8, HÀC(3)); 5.84 (dddd, J ˆ 17.4, 10.3, 6.2, 5.3, CHˆCH2); 5.57 (s, PhCH); 5.32 (d, J ꢀ 4.4, HÀC(1)); 5.32
(dq, J ˆ 17.4, 1.6, CHˆCH2); 5.27 (dd, J ˆ 9.8, 3.7, HÀC(2)); 5.15 (dq, J ˆ 10.3, 1.3, CHˆCH2); 4.36 (dd, J ˆ 10.3,
4.7, HeqÀC(6)); 4.25 (ddt, J ˆ 13.1, 5.3, 1.6, OCH2CHˆCH2); 4.15 (td, J ˆ 10.3, 5.0, HÀC(5)); 4.04 (ddt, J ˆ 13.1,
6.2, 1.2, OCH2CHˆCH2); 3.91 (t, J ꢀ 9.5, HÀC(4)); 3.85 (t, J ˆ 10.3, HaxÀC(6)). 13C-NMR (75 MHz, CDCl3):
166.0, 165.6 (2s, 2 CˆO); 136.9 (s of PhCH); 133.4, 133.31 (2d of Bz); 133.06 (d of CHˆCH2); 130.0, 129.8 (4d of
Bz, 2s of Bz); 129.1 (d of PhCH); 128.5, 128.34, 128.25 (2d of PhCH, 4d of Bz); 126.2 (2d of PhCH); 118.0 (t,
CHˆCH2); 101.7 (d, PhCH); 69.7 (t, OCH2CHˆCH2); for data of C(1) C(6), see Table 8.
Benzoylation of 40. According to the General Procedure: a) 40 (71 mg, 0.25 mmol) with (S)-1 (5 mol-%)
followed by FC (cyclohexane AcOEt 2 :1) gave 41 [53] (80 mg, 83%).
b) 40 (71 mg, 0.25 mmol) with (R)-1 (5 mol-%) followed by FC (cyclohexane/AcOEt 2 :1) gave 41 (81 mg,
83%).
c) 40 (71 mg, 0.25 mmol) with TMEDA (5 mol-%) followed by FC (cyclohexane AcOEt 2 :1) gave 42
[53][54] (6 mg, 5%) and 41 (82 mg, 84%).
Benzoylation of 43. According to the General Procedure: a) 43 (71 mg, 0.25 mmol) with (S)-1 (5 mol-%)
followed by FC (CH2Cl2/AcOEt 9 :1) gave 46 [53][58] (9 mg, 7%), 44 [53][58] (44 mg, 46%), and 45 [53][58]
(32 mg, 33%).
b) 43 (71 mg, 0.25 mmol) with (R)-1 (5 mol-%) followed by FC (CH2Cl2/AcOEt 9 :1) gave 46 (10 mg,
10%), 44 (25mg, 26%), and 45 (52mg, 54%).
c) 43 (71mg, 0.25mmol) with TMEDA (5 mol-%) followed by FC (CH2Cl2/AcOEt 9 :1) gave 46 (18 mg,
15%), 44 (62 mg, 64%), and 45 (6 mg, 6%).
Methyl 2,3-Di-O-benzoyl-4,6-O-benzylidene-a-d-galactopyranoside (46) [53][58]. 1H-NMR (300 MHz,
CDCl2): 8.05 7.98 (m, 4 arom. H); 7.57 7.46 (m, 4 arom. H); 7.42 7.32 (m, 7 arom. H); 5.86 5.74 (AB, irrad. at
4.66 ! change, HÀC(2), HÀC(3)); 5.58 (s, PhCH); 5.29 (br. d, J ꢀ 1.9 (virtual coupling), HÀC(1)); 4.66 (br. d,
J ꢀ 1.2 (virtual compling), HÀC(4)); 4.37 (dd, J ˆ 12.5, 1.6, HÀC(6)); 4.15 (dd, J ˆ 12.5, 1.6, H'ÀC(6)); 3.91 (br.
s, HÀC(5)); 3.47 (s, MeO). 13C-NMR (75 MHz, CDCl3): 166.1, 165.8 (2s, 2 CˆO); 137.5 (s of PhCH); 133.16,
133.12 (2d of Bz); 129.78, 129.76 (4d of Bz); 129.46, 129.41 (2s of Bz); 128.8 (d of PhCH); 128.3, 128.1 (4d of Bz,
2d of PhCH); 126.1 (2d of PhCH); 100.7 (d, PhCH); 55.0 (q, MeO); for data of C(1) C(6), see Table 8.
Benzoylation of 47. According to the General Procedure: a) 47 (71 mg, 0.25 mmol) with (S)-1 (5 mol-%)
followed by FC (hexane/AcOEt 2 :1) gave 48 [55][64][65] (86 mg, 90%).
b) 47 (71 mg, 0.25 mmol) with (R)-1 (5 mol-%) followed by FC (hexane/AcOEt 2 :1) gave 48 (60 mg, 63%)
and 47 (16 mg, 23%).
Benzoylation of 49. According to the General Procedure: a) 49 (71 mg, 0.25 mmol) with (S)-1 (5 mol-%)
followed by FC (cyclohexane/AcOEt 9 :1 ! 1:1) gave 50 [55][66] (6 mg, 6%), 51 [55] [65 67] (82 mg, 85%),
and 49 (6 mg).
b) 49 (71 mg, 0.25 mmol) with (R)-1 (5 mol-%) followed by FC (cyclohexane/AcOEt 9 :1 ! 1:1) gave 52
[55][68] (5 mg, 4%), 50 (18 mg, 19%), 51 (60 mg, 62%), and 49 (8 mg).
c) 49 (71 mg, 0.25 mmol) with TMEDA (5 mol-%) followed by FC (cyclohexane/AcOEt 9 :1 ! 1:1) gave
52 (11 mg, 9%), 50 (8 mg, 8%), 51 (73mg, 74%), and 49 (8 mg).
Methyl 2,3-Di-O-benzoyl-4,6-O-benzylidene-a-d-mannopyranoside (52) [68][69]. 1H-NMR (300 MHz,
CDCl3): 8.13 8.06 ( m, 2 arom. H); 7.95 7.88 (m, 2 arom. H); 7.67 7.59 (m, 1 arom. H); 7.55 7.41 (m, 5 arom.
H); 7.38 7.27 (m, 5 arom. H); 5.80 (dd, J ˆ 10.3, 3.4, HÀC(3)); 5.69 (dd, J ˆ 3.7, 1.6, HÀC(2)); 5.67 (s, PhCH);
4.90 (d, J ꢀ 1.6, HÀC(1)); 4.38 (dd, J ˆ 10.3, 4.7, HÀC(6)); 4.32 (t, J ˆ 10.0, HÀC(4)); 4.11 (td, J ˆ 10.0, 4.7,
HÀC(5)); 3.96 (t, J ˆ 10.0, H'ÀC(6)); 3.49 (s, MeO). 13C-NMR (75 MHz, CDCl2): 165.3, 165.2 (2s, 2 CˆO);

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137.0 (s of PhCH); 133.4, 132.9 (2d of Bz); 129.8, 129.7 (4d of Bz); 129.6, 129.4 (2s of Bz); 129.0 (d of PhCH);
128.5, 128.1 (4d of Bz, 2d of PhCH); 126.1 (2d of PhCH); 101.9 (d, PhCH); 55.4 (q, MeO); for data of C(1)
C(6), see Table 8.
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Received July 9, 2002