Stereoselective synthesis of 3-amino-3-deoxy-aldohexoses by aldol condensation of tricarbonyliron-α-Aminodienone complexes: Total synthesis of multiprotected kanosamine

Article abstract of DOI:10.1055/s-0030-1258320

An aldol reaction between the divalent tin enol ether of racemic N-Boc α-aminodienone-tricarbonyliron complex and multiprotected d-glyceraldehyde provided predominantly two enantiomerically pure ketol diastereoisomers. From there, multiprotected kanosamin

Full text of DOI:10.1055/s-0030-1258320

PAPER
161
Stereoselective Synthesis of 3-Amino-3-deoxy-aldohexoses by Aldol
Condensation of Tricarbonyliron–a-Aminodienone Complexes:
Total Synthesis of Multiprotected Kanosamine
T
otal
Synthesis
a
of Multipro
u
tected
K
ano
r
samine ence Miesch,*a Tania Welsch,a Loic Toupetb
a
Université de Strasbourg- Institut de Chimie – UMR 7177, Laboratoire de Chimie Organique Synthétique, 1 rue Blaise Pascal,
BP 296/R8, 67008 Strasbourg cedex, France
Fax +33(3)688517 54; E-mail: lmiesch@unistra.fr
Université de Rennes 1-Institut de Physiques-IPR-UMR 6251, Bâtiment 11A, 35042 Rennes cedex, France
b
Received 22 September 2010; revised 5 October 2010
ethylsilyl)-D-glyceraldehyde (7). Subsequent reduction of
the carbonyl group adjacent to the diene unit, protection of
the alcohol functions, decomplexation, and ozonolysis led
to multiprotected 3-amino-3-deoxysugars (Scheme 1).
Abstract: An aldol reaction between the divalent tin enol ether of
racemic N-Boc a-aminodienone–tricarbonyliron complex and mul-
tiprotected D-glyceraldehyde provided predominantly two enantio-
merically pure ketol diastereoisomers. From there, multiprotected
kanosamine and 3-amino-3-deoxy-D-altrose were obtained in a few
high-yielding steps, namely stereoselective reduction, protection,
decomplexation, and ozonolysis.
PG1HN
CH2OPG2
OPG2
M = Fe(CO)3
PG1HN
O
CH2OPG2
OPG2
Key words: a-aminodienone–tricarbonyliron complexes, divalent
tin enol ether , aldol reactions, kanosamine, amino sugars
OH
PG3O
M
CHO OPG3
NHPG1
Kanosamine (3-amino-3-deoxy-D-glucose, Figure 1) was
first isolated as one of the products resulting from acid hy-
drolysis of kanamycin.1 The same compound was identi-
fied as an antibiotic produced by Bacillus
aminoglucosidicus.2 Kanosamine is the only amino sugar
that is an antibiotic; it exhibited a strong inhibitory effect
on the growth of some plant-pathogenic fungi, oomycet-
es,3,4 which represents an attractive alternative to synthet-
ic pesticides. Kanosamine biosynthesis has been directly
implicated as a source of the nitrogen atom in the ami-
noshikimate pathway.5,6
O
CHO
+
PG2O
M
OPG2
3
7
Scheme 1 Retrosynthetic scheme for the synthesis of aminopolyols
using tricarbonyliron–dienone complexes
In continuation of our work in cross-aldol condensation
reactions between aldehydes and dienone–tricarbonyliron
complexes we showed first that the trimethylsilyl enol
ether of hepta-3,5-dien-2-one–tricarbonyliron complex
underwent a highly stereoselective cross-aldol condensa-
tion reaction in the presence of titanium(IV) chloride co-
ordinated benzyloxylactaldehyde.9 Second, divalent tin
enol ether of complexed N-Boc-a-aminoheptadienone re-
acted with both enantiomers of protected lactaldehydes
yielding predominantly one enantiomerically pure ketol
diastereoisomer. These reaction conditions were used to
achieve the total synthesis of multiprotected
kanosamine.10
CHO
CH2OH
NH2
OH
H
OH
H
H
H
O
H2N
H
H
H
OH
OH
H
H
HO
OH
CH2OH
kanosamine
3-amino-3-deoxy-β-D-glucose
Figure 1 Structure of 3-amino-3-deoxy-b-D-glucose or kanosamine
The synthesis of kanosamine has been reported three
times,5,7,8 always starting from natural amino sugars.
The synthesis of protected a-amino ketone complex 3 was
achieved from readily available bromodienone complex 1
via azide complex 2. The required azide 2 was obtained by
SN2 displacement of the bromine atom with sodium azide
in the presence of 15-crown-5 ether.11 Azide 2 was trans-
formed into amine 3 by catalytic hydrogenation under
pressure (15 bar) in the presence of di-tert-butyl
dicarbonate12 (Scheme 2).
We report herein a quite different synthetic approach to
kanosamine involving a highly diastereoselective cross-
aldol condensation reaction between a-aminodienone–tri-
carbonyliron complex 3 and (+)-2,3-di-O-(tert-butyldim-
SYNTHESIS 2011, No. 1, pp 0161–0167
x
x
.
x
x
.2
0
1
0
Advanced online publication: 28.10.2010
DOI: 10.1055/s-0030-1258320; Art ID: Z23610SS
© Georg Thieme Verlag Stuttgart · New York
Preparation of 2,3-di-O-(tert-butyldimethylsilyl)-D-glyc-
eraldehyde (7) was achieved according Jurcsak’s proce-

162
L. Miesch et al.
PAPER
O
O
O
H
O
OH OR
N3
NHBoc
Br
Pb(OAc)4, toluene
96%
OR
2) H2, Pd/C
Boc2O
RO
RO
NaN3
M
OR
M
M
OR OH
15-crown-5
CH2Cl2
97%
MeOH
97%
R = TBS
7
6
3
1
2
Scheme 5 2,3-Di-O-(tert-butyldimethylsilyl)-D-glyceraldehyde (7)
M = Fe(CO)3
Scheme 2 Synthesis of amino ketone 3
subjected to an aldolization reaction using enantiomeri-
cally pure complex (+)-3, compound 8 was obtained al-
most exclusively. This result is consistent with the
previous results. On the other hand, when complex (–)-3
was involved in the aldolization process, compounds 9,
10a, and 10b were obtained (Table 1). This approach out-
lines an efficient way to introduce three of the four stereo-
genic centers present in kanosamine.
dure.13 Commercially available 1,2,5,6-di-O-isoprop-
ylidene-D-mannitol (4) was benzylated under phase-trans-
fer conditions14 followed by hydrolysis to give 3,4-di-O-
benzyl-D-mannitol (5) (Scheme 3).
OH
O
OBn OH
To generate the last stereogenic center present in the nat-
ural aminopolyols, the carbonyl group of the complexed
dienones 8 and 9 have to be reduced stereochemically. To-
ward this end, compounds 8 and 9 were treated with bo-
rane–dimethyl sulfide complex. The reduction proceeded
from side the opposite side to the metal center, affording
compounds 11 and 12 after diacetylation (Scheme 6). The
stereochemistry of 12 was confirmed by X-ray crystallog-
raphy,16 which established unambiguously the absolute
configuration of compound 12 (RSRSR).
1) BnBr, NaOH
H2O, Bu4NBr, THF
O
OH
HO
O
2) AcOH, H2O, 45 °C
87%
O
OH
OH OBn
4
5
Scheme 3 Synthesis of 3,4-di-O-benzyl-D-mannitol (5)
The treatment of 3,4-di-O-benzyl-D-mannitol (5) with
tert-butylchlorodimethylsilane and imidazole in anhy-
drous N,N-dimethylformamide followed by hydrogena-
tion in the presence of 10% palladium on charcoal gave
the 3,4-dihydroxy derivate 6 with a good yield
(Scheme 4). Debenzylation carried out with sodium in liq-
uid ammonia13 led to compound 7 in poor yield.
BocHN
CH2OR
R = TBS; M = Fe(CO)3
AcO
S
S
R
OR
R
OAc
S
1) BH3⋅Me2S, THF, 25 °C, 82%
8
M
Protected D-glyceraldehyde 7 was prepared in good yield
and high purity when compound 6 was cleaved with lead
tetraacetate (Scheme 5).
2) Ac2O, Et3N, DMAP, CH2Cl2, 0 °C
88%
11
The divalent tin enol ether of a racemic N-Boc a-amino-
dienone–tricarbonyliron complex was previously shown
to react with both enantiomers of protected lactaldehydes
to yield predominantly one enantiomerically pure ketol
diastereomer.15 Based on this precedence, we investigated
the addition of 2,3-di-O-(tert-butyldimethylsilyl)-D-glyc-
eraldehyde (7) to the divalent tin enolate of racemic amino
ketone 3 in the presence of N-ethylpiperidine (NEP). This
reaction led in a good overall yield to a mixture of four
diastereomeric ketols. The major diastereomer 8 (38%)
was separated by silica gel column chromatography from
ketol 9 (23%), and ketols 10a and 10b (18%).
BocHN
CH2OR
AcO
S
R
R
OR
S
OAc
R
1) BH3⋅Me2S, THF, 25 °C, 82%
2) Ac2O, Et3N, DMAP, CH2Cl2, 0 °C
97%
9
M
12
Scheme 6 Reduction and diacetylation of complexed dienones 8
and 9
Decomplexation of the dienes 11 and 12 was best per-
formed using cerium(IV) ammonium nitrate (CAN)10 in
methanol at 0 °C yielding both dienes 13 and 14 with good
yields (Scheme 7).
Although the aldolization step provided the major ketol 8
in only 38% yield, the result is significant, because this al-
dolization step also constitutes a resolution. When 2,3-di-
O-(tert-butyldimethylsilyl)-D-glyceraldehyde (7) was
Cleavage of the diene moieties of 13 and 14 into formyl
groups was achieved by subsequent ozonolysis in meth-
OH OR
OBn OH
1) TBSCl, imidazole
DMF, 75%
OR
OH
RO
HO
2) H2 (45 bar), Pd/C
EtOAc, AcOH, 94%
OR OH
OH OBn
R = TBS
6
5
Scheme 4 1,2,5,6-Tetra-O-(tert-butyldimethylsilyl)-D-mannitol (6)
Synthesis 2011, No. 1, 161–167 © Thieme Stuttgart · New York

PAPER
Total Synthesis of Multiprotected Kanosamine
163
Table 1 Cross-Aldol Condensation between Amino Ketone 3 and Protected D-Glyceraldehyde 7
M = Fe(CO)3
R = TBS
BocHN
CH2OR
BocHN
CH2OR
NHBoc
BocHN
CH2OR
O
O
O
O
S
S
R
R
R
S
R
OR
OR
OR
1) Sn(OTf)2, NEP
CH2Cl2, –78 °C, 2 h
OH
OH
S
R
R
OH
M
+
M
+
M
M
O
R
2) RO
H
2 diastereoisomers
(1:1.6)
7
OR
CH2Cl2, –30 °C, 3 h
9
3
8
10a,b
Amino ketone
Yield (%)
8
9
10a, 10b
( )-3
(+)-3
(–)-3
38
74
1
23
1
18
1
24
51
BocHN
CH2OR
anol at –78 °C followed by reduction with dimethyl sul-
fide to provide respectively multiprotected kanosamine
15 and 3-amino-3-deoxy-D-altrose 16 in high yields
(Scheme 8).
BocHN
CH2OR
AcO
S
AcO
S
S
R
R
OR
R
R
OR
S
CAN, MeOH
OAc
S
OAc
93%
M
Structure of compound 15 (multiprotected kanosamine)
was confirmed by X-ray crystallographic analysis17
(Figure 2).
11
13
BocHN
CH2OR
BocHN
CH2OR
AcO
S
AcO
S
R
R
S
R
OR
OR
S
R
CAN, MeOH
85%
OAc
OAc
R
M
12
14
R = TBS
M = Fe(CO)3
Scheme 7 Decomplexation of compound 11 and 12
BocHN
CH2OR
AcO
BocHN
CH2OR
S
R
R
OR
S
AcO
S
S
R
OAc
OR
1) O3, MeOH, –78 °C
R
OAc
2) Me2S, –78 °C to 25 °C
88%
O
H
Figure 2 X-ray structure of compound 15
15
13
multi-protected kanosamine
In conclusion, we achieved simultaneously a stereoselec-
tive synthesis of enantiopure multiprotected kanosamine
and of 3-amino-3-deoxyaltrose. The cross-aldol reaction
between the divalent tin enol ether of a-aminodienone–
tricarbonyliron complex and multiprotected D-glyceralde-
hyde allowed the resolution of the tricarbonyliron com-
plex and constitutes an excellent way to introduce three of
the four stereogenic centers present in the amino sugars.
BocHN
AcO
CH2OR
BocHN
CH2OR
S
S
R
OR
1) O3, MeOH, –78 °C
AcO
R
S
R
R
OR
S
OAc
OAc
2) Me2S, –78 °C to 25 °C
90%
O
H
16
14
multi-protected
3-amino-3-deoxy-D-altrose
The iron carbonyl appendage can be considered as a valu-
able tool due to its ability either to reduce dienones ste-
reospecifically on the opposite side of the metal, thus
giving access to the fourth stereogenic center of the amino
sugars, and then to generate the formyl group by cleavage
of the diene moiety.
Scheme 8 Synthesis of multiprotected kanosamine 15 and 3-amino-
3-deoxy-D-altrose 16
Synthesis 2011, No. 1, 161–167 © Thieme Stuttgart · New York

164
L. Miesch et al.
PAPER
Reactions were carried out under a positive pressure of argon with
magnetic stirring and degassed solvents in oven-dried glassware.
Et2O and THF were distilled from Na/benzophenone. CH2Cl2 was
distilled over P2O5. MeOH was distilled over Mg and stored over
3 Å MS. TLC was carried out on silica gel plates Merck 60F254 and
the spots were visualized under a UV lamp (254 or 365 nm) and/or
sprayed with a soln of vanillin (25 g) in EtOH–H2SO4 (98:2, 1 L) or
with phosphomolybdic acid followed by heating on a hot plate. Col-
umn chromatography used silica gel (Merck, Si60, 40–60 mm); pe-
troleum ether = PE. Melting points were measured on a hot stage
Stuart Scientific SMP 3 apparatus. 1H NMR spectra were recorded
at 200 or 300 MHz and 13C NMR spectra at 75 or 125 MHz on a
Bruker AC-300 or ARX-500 using the signal of the residual non-
purified by chromatography (silica gel, cyclohexane–EtOAc,
90:10) affording pure 3,4-di-O-benzyl-1,2:5,6-di-O-isopropy-
lidene-D-mannitol (2.21 g, 87%).
[a]D20 +24 (c 1.0, CHCl3).
1H NMR (300 MHz, CDCl3): d = 7.25–7.35 (m, 10 H), 4.70 (s, 4 H),
4.24 (t, J = 6.2 Hz, 2 H), 4.00 (dd, J = 8.2, 6.2 Hz, 2 H), 3.85 (dd,
J = 8.3, 6.5 Hz, 2 H), 3.77–3.79 (d, J = 5.9 Hz, 2 H), 1.41 (s, 6 H),
1.33 (s, 6 H).
13C NMR (75 MHz, CDCl3): d = 138.4, 128.5, 128.2, 127.9, 108.7,
80.1, 76.0, 74.7, 66.9, 26.8, 25.4.
Anal. Calcd for C26H36O6: C, 70.56; H, 7.74. Found: C, 70.59; H,
7.88.
1
deuteriated solvent as the internal reference; significant H NMR
spectroscopic data are given. The ratios of compounds indicated be-
low were calculated from the NMR integrations. IR spectra were re-
corded as CCl4 solns on a Perkin Elmer IR-881 and on a Bruker
Alpha spectrophotometer. Microanalysis were carried out by the
Service Commun d’Analyses du CNRS, Institut de Chimie-
Strasbourg.
3,4-Di-O-benzyl-D-mannitol (5)
3,4-Di-O-benzyl-1,2:5,6-di-O-isopropylidene-D-mannitol was dis-
solved in 70% aq AcOH (35 mL) and the soln was stirred at 45 °C
for 6 h. After cooling and evaporation of the solvent, the oily residue
was crystallized (anhyd acetone–Et2O) to give 5 (2.978 g, 100%) as
highly hygroscopic, colorless crystals. Because of its hygroscopic
character, no analytical data of 5 could be obtained.
(h4-1-Azido-2-oxohepta-3,5-diene)tricarbonyliron (2)
To a suspension of NaN3 (5.93 g, 91.2 mmol) and 15-crown-5 (1.34
g, 6.1 mmol) in CH2Cl2 (40 mL) was added a soln of a-bromo ke-
tone 1 (2.00 g, 6.1 mmol) in CH2Cl2 (30 mL). The mixture was
stirred at r.t. for 4 h, filtered through a pad of Celite and concentrat-
ed in vacuo. Purification of the resulting residue by column chroma-
tography (silica gel, PE–Et2O, 80:20) provided azide 2 (1.72 g,
97%).
3,4-Di-O-benzyl-1,2:5,6-tetra-O-(tert-butyldimethylsilyl)-D-
mannitol and 1,2,5,6-Tetra-O-(tert-butyldimethylsilyl)-D-man-
nitol (6)
3,4-Di-O-benzyl-1,2:5,6-tetra-O-(tert-butyldimethylsilyl)-D-
mannitol
To a soln of 5 (2.21 g, 6.10 mmol) in anhyd DMF (35 mL), TBSCl
(4.412 g, 29.27 mmol) and imidazole (1.993 g, 29.27 mmol) were
added under an argon atmosphere. The mixture was stirred at r.t. for
48 h, filtered through a pad of Celite, poured into H2O (50 mL), and
extracted with pentane. The combined extracts were dried (Na2SO4)
and concentrated. The residue was purified by chromatography (sil-
ica gel, pentane–EtOAc, 98:2) providing 3,4-di-O-benzyl-1,2:5,6-
tetra-O-(tert-butyldimethylsilyl)-D-mannitol (3.775 g, 75%).
[h4-1-(tert-Butoxycarbonylamino)-2-oxohepta-3,5-diene]tricar-
bonyliron (3)
A soln of azide 2 (0.638 g, 2.19 mmol) in MeOH (35 mL) was hy-
drogenated in the presence of 10% Pd/C (0.500 g) and Boc2O (1.436
g, 6.58 mmol) under reduced pressure (15 bar) for 15 h. After filtra-
tion to remove the catalyst and concentration in vacuo, the residue
was purified by chromatography (silica gel, PE–EtOAc, 80:20) to
yield 3 (0.725 g, 93%).
[a]D20 +14 (c 1.0, CHCl3).
1H NMR (300 MHz, C6D6): d = 7.02–7.44 (m, 10 H), dA = 4.84,
dB = 4.94 (syst AB, JAB = 11.5 Hz, Dn = 29.4 Hz, 4 H), 3.87–4.24
(m, 8 H), 1.02 (s, 18 H), 0.94 (s, 18 H), 0.21 (s, 6 H), 0.19 (s, 6 H),
0.04 (s, 12 H).
13C NMR (75 MHz, C6D6): d = 139.7, 128.5, 127.8, 127.6, 82.7,
76.3, 74.9, 65.6, 26.4, 18.6, 18.5, –3.7, –4.2, –5.0, –5.1.
IR (CCl4): 3431, 2063, 2003, 1988, 1721, 1687 cm–1.
1H NMR (300 MHz, CDCl3): d = 5.84 (dd, J = 8.2, 5.6 Hz, 1 H),
5.27 (dd, J = 9.1, 5.4 Hz, 1 H), 5.20–5.30 (m, NH, 1 H), 3.97 (d,
J = 4.6 Hz, 2 H), 1.51–1.62 (m, 1 H), 1.49 (d, J = 6.0 Hz, 3 H), 1.44
(s, 9 H), 1.15 (d, J = 8.2 Hz, 1 H).
13C NMR (75 MHz, CDCl3): d = 200.4, 155.6, 89.1, 81.0, 79.7, 59.8,
50.0, 49.8, 28.4, 19.1.
Anal. Calcd for C44H82O6Si4: C, 64.49; H, 10.09. Found: C, 64.00;
H, 10.04.
1,2,5,6-Tetra-O-(tert-butyldimethylsilyl)-D-mannitol (6)
To a soln of 3,4-di-O-benzyl-1,2:5,6-tetra-O-(tert-butyldimethylsi-
lyl)-D-mannitol (1.935 g, 2.36 mmol) in a mixture of EtOAc–AcOH
(3:1, 36 mL), 10% Pd/C (0.1 g) was added, and the resulting suspen-
sion was hydrogenated for 16 h (45 bar, 45 °C). The catalyst was
then filtered off and solvents were evaporated. The residue was pu-
rified by chromatography (silica gel, PE–EtOAc, 95:5) providing 6
(1.420 g, 94%).
[a]D20 –14 (c 1.0, CHCl3).
IR (CCl4): 3480 cm–1.
1H NMR (300 MHz, C6D6): d = 3.64–3.86 (m, 8 H), 3.36 (d, J = 4.1
Hz, 2 H), 0.90 (s, 18 H), 0.89 (s, 18 H), 0.12 (s, 6 H), 0.10 (s, 6 H),
0.06 (s, 12 H).
Complex (+)-3
Similarly, enantiomerically pure complex (+)-3 {[a]D20 +218 (c 1.0
CHCl3); 98% ee [HPLC (Chiralcel OJ, isohexane–i-PrOH)]} was
20
obtained from the corresponding bromodienone complex ([a]D
+242 (c 1.2 CHCl3).10
Complex (–)-3
[a]D20 –209 (c 1.0 CHCl3).
3,4-Di-O-benzyl-1,2:5,6-di-O-isopropylidene-D-mannitol and
3,4-Di-O-benzyl-D-mannitol (5)
3,4-Di-O-benzyl-1,2:5,6-di-O-isopropylidene-D-mannitol
To a vigorously stirred mixture of 50% aq NaOH (25 mL), THF (10
mL), BnBr (1.5 mL, 12.58 mmol), and Bu4NBr (0.295 g, 0.91
mmol), 1,2,5,6-di-O-isopropylidene-D-mannitol (4, 1.5 g, 5.72
mmol) in THF (25 mL) was added dropwise. The mixture was
stirred at 40 °C for 7 h then at r.t. for 16 h. The phases were separat-
ed, the aqueous phase was extracted with Et2O. The organic layer
was dried (Na2SO4). The soln was concentrated and the residue was
13C NMR (75 MHz, C6D6): d = 74.4, 70.7, 65.7, 26.1, 26.0, 18.5,
18.2, –4.2, –4.8, –5.3.
Anal. Calcd for C30H70O6Si4: C, 56.37; H, 11.04. Found: C, 56.46;
H, 11.08.
Synthesis 2011, No. 1, 161–167 © Thieme Stuttgart · New York

PAPER
Total Synthesis of Multiprotected Kanosamine
165
2,3-Di-O-(tert-butyldimethylsilyl)-D-glyceraldehyde (7)
1,2,5,6-Tetra-O-(tert-butyldimethylsilyl)-D-mannitol (6, 0.700 g,
1.10 mmol) was suspended in anhyd toluene (20 mL). The suspen-
sion was cooled to 5 °C, and Pb(OAc)4 (0.534 g, 1.20 mmol) was
added. The mixture was stirred at r.t. for 4 h and then filtered
through a pad of Celite. Anhyd K2CO3 (6.000 g) was added to the
filtrate and the resulting suspension was stirred at r.t. for 2 h. Inor-
ganic salts were filtered off and the solvent was evaporated. Crude
aldehyde was purified by column chromatography (silica gel, PE–
EtOAc) affording 7 (0.671 g, 96%).
[a]D20 +6 (c 1.0 CHCl3).
IR (CCl4): 1739 cm–1.
1H NMR (300 MHz, CDCl3): d = 9.64 (d, J = 1.2 Hz, 1 H), 4.04 (td,
J = 5.2, 1.1 Hz, 1 H), 3.78 (d, J = 5.2 Hz, 2 H), 0.91 (s, 9 H), 0.87
(s, 9 H), 0.09 (s, 3 H), 0.08 (s, 3 H), 0.05 (s, 3 H), 0.04 (s, 3 H).
13C NMR (75 MHz, CDCl3): d = 204.3, 156.0, 89.1, 81.6, 80.0, 75.4,
73.6, 65.2, 59.8, 59.3, 52.4, 28.4, 26.0, 26.1, 19.2, 18.3, 18.4, –5.4,
–4.5, –4.3.
Anal. Calcd for C30H53O9NSi2Fe: C, 52.70; H, 7.81; N, 2.05. Found:
C, 53.02; H, 7.86; N, 1.44.
Compound 10a
[a]D20 –75 (c 1.0, CHCl3).
IR (CCl4): 1690, 1721, 2062, 2003, 1982, 3438, 3460 cm–1.
1H NMR (300 MHz, CDCl3): d = 5.84 (dd, J = 8.1, 5.0 Hz, 1 H),
5.37 (d large, J = 9.2 Hz, 1 H), 5.27 (dd, J = 8.2, 5.3 Hz, 1 H), 4.38
(d large, J = 9.1 Hz, 1 H), 4.16 (d large, J = 7.1 Hz, 1 H), 3.91 (s
large, 1 H), 3.80–3.89 (m, 1 H), 3.60–3.75 (m, 2 H), 1.50–1.65 (m,
1 H), 1.48 (d, J = 5.9 Hz, 3 H), 1.42 (s, 9 H), 0.92 (s, 9 H), 0.89 (s,
9 H), 0.80–0.95 (m, 1 H), 0.11 (s, 3 H), 0.10 (s, 3 H), 0.08 (s, 3 H),
0.07 (s, 3 H).
13C NMR (75 MHz, CDCl3): d = 204.4, 156.3, 89.2, 82.6, 79.5, 76.1,
69.9, 67.5, 60.1, 59.2, 50.3, 28.5, 25.9, 26.0, 19.2, 18.1, 18.3, –5.6,
–5.5, –5.1, –4.2.
13C NMR (75 MHz, CDCl3): d = 203.3, 79.0, 64.8, 25.9, 26.0, 18.3,
18.4, –5.4, –5.3, –4.7, –4.6.
Anal. Calcd for C15H34O3Si2: C, 55.62; H, 10.83. Found; C, 56.55;
H, 10.76.
Compound 10b
Compounds 8, 9, 10a, and 10b; General Procedure
[a]D20 –46 (c 1.0 CHCl3).
To a soln of Sn(OTf)2 (1.674 g, 4.02 mmol) and N-ethylpiperidine
(0.62 mL, 4.52 mmol) in anhyd CH2Cl2 (20 mL) was added drop-
wise at –78 °C a soln of amino ketone 3 (0.612 g, 1.67 mmol) in
CH2Cl2 (10 mL). The mixture was stirred at –78 °C for 2 h. A soln
of 7 (0.800 g, 2.51 mmol) in CH2Cl2 (10 mL) was then added drop-
wise. The resulting mixture was stirred at –30 °C, quenched by ad-
dition of sat. aq NaHCO3, and filtered through a pad of Celite. The
aqueous layer was extracted with CH2Cl2 and Et2O. The combined
organic extracts were washed with brine, dried (Na2SO4), and con-
centrated in vacuo. Purification of the resulting residue by column
chromatography (silica gel, PE–EtOAc, 80:20) provided, in order of
elution, compound 9 (0.262 g, 23%), a mixture of ketols 10a and
10b (in a ratio 1:1.6, 0.229 g, 18%), and compound 8 (0.437 g,
38%).
IR (CCl4): 1670, 1721, 2062, 2003, 1984, 3440, 3540 cm–1.
1H NMR (300 MHz, CDCl3): d = 5.82 (dd, J = 8.2, 5.0 Hz, 1 H),
5.42 (d large, J = 8.1 Hz, 1 H), 5.25 (dd, J = 7.2, 5.0 Hz, 1 H), 4.21
(d large, J = 8.0 Hz, 1 H), 4.10 (s large, 1 H), 3.60–3.80 (m, 3 H),
2.83 (d, J = 4.2 Hz, 1 H), 1.46 (d, J = 6.6 Hz, 3 H), 1.43 (s, 9 H),
1.35–1.50 (m, 1 H), 0.89 (s, 18 H), 0.80–0.95 (m, 1 H), 0.09 (s, 6
H), 0.07 (s, 3 H), 0.06 (s, 3 H).
13C NMR (75 MHz, CDCl3): d = 203.7, 156.0, 89.1, 81.7, 79.8, 73.0,
71.2, 65.1, 60.4, 59.0, 50.2, 28.4, 26.0, 26.1, 19.1, 18.2, 18.4, –5.4,
–5.3, –4.8, –4.1.
Compound 11; Typical Procedures
To a soln of ketol 8 (0.273 g, 0.40 mmol) in anhyd THF (10 mL) at
0 °C was added dropwise 2 M BH3–Me2S in THF (0.22 mL, 0.44
mmol). The resulting soln was stirred at r.t. for 4 h, and then diluted
with MeOH (30 mL) and H2O (30 mL). The aqueous layer was ex-
tracted with Et2O. The organic layer was washed with H2O and
brine, dried (Na2SO4), and concentrated in vacuo. Purification of the
resulting residue by chromatography (silica gel, PE–EtOAc, 9:1)
provided the diol (0.226 g, 82%) as an orange oil.
Compound 8
[a]D20 +45 (c 1.0 CHCl3).
IR (CCl4): 1670, 1721, 2062, 2001, 1983, 3442, 3480 cm–1.
1H NMR (300 MHz, CDCl3): d = 5.84 (dd, J = 7.8, 5.0 Hz, 1 H),
5.45 (d large, J = 9.3 Hz, 1 H), 5.24 (dd, J = 7.2, 5.2 Hz, 1 H), 4.28
(d large, J = 9.1 Hz, 1 H), 4.10 (d large, J = 7.0 Hz, 1 H), 3.77–3.88
(m, 1 H), 3.75 (s large, 1 H), 3.63 (d, J = 6.6 Hz, 2 H), 1.46 (d,
J = 5.9 Hz, 3 H), 1.43 (s, 9 H), 1.40–1.50 (m, 1 H), 0.89 (m, 9 H),
0.88 (s, 9 H), 0.80–0.95 (m, 1 H), 0.09 (s, 3 H), 0.08 (s, 6 H), 0.06
(s, 3 H).
13C NMR (75 MHz, CDCl3): d = 204.7, 156.0, 89.0, 81.6, 79.5, 75.2,
69.8, 67.6, 59.8, 58.6, 50.3, 28.4, 25.9, 19.3, 18.0, 18.3, –5.5, –5.4,
–5.2, –4.2.
[a]D20 –45 (c 1.0 CHCl3).
IR (CCl4): 1718, 2046, 1975, 1967, 3420, 3443 cm–1.
1H NMR (300 MHz, CDCl3): d = 5.28 (d large, J = 9.7 Hz, 1 H),
5.21 (dd, J = 8.4, 5.0 Hz, 1 H), 5.06 (dd, J = 8.6, 5.0 Hz, 1 H), 4.18
(s large, 1 H), 3.97 (d large, J = 7.0 Hz, 1 H), 3.84 (dd, J = 9.1, 3.2
Hz, 1 H), 3.79 (dd, J = 9.3, 5.1 Hz, 1 H), 3.66 (q, J = 7.7 Hz, 1 H),
3.55–3.65 (m, 2 H), 3.28 (d, J = 1.9 Hz, 1 H), 1.43 (s, 9 H), 1.40 (d,
J = 8.2 Hz, 3 H), 1.07–1.16 (m, 1 H), 0.97 (t, J = 8.3 Hz, 1 H), 0.91
(s, 9 H), 0.90 (s, 9 H), 0.11 (s, 3 H), 0.10 (s, 3 H), 0.06 (s, 6 H).
Anal. Calcd for C30H53O9NSi2Fe: C, 52.70; H, 7.81; N, 2.05. Found:
C, 52.91; H, 7.92; N, 2.16.
13C NMR (75 MHz, CDCl3): d = 157.0, 86.1, 81.5, 79.6, 77.8, 76.9,
69.8, 67.6, 64.0, 57.8, 55.8, 28.5, 25.9, 26.0, 19.2, 18.1, 18.3, –5.5,
–5.4, –5.0, –4.1.
Compound 9
[a]D20 –74 (c 1.0 CHCl3).
IR (CCl4): 1672, 1720, 2062, 2002, 1985, 3400, 3440 cm–1.
Anal. Calcd for C30H55O9NSi2Fe: C, 52.54; H, 8.08; N, 2.04. Found:
C, 52.34; H, 8.21; N, 1.61.
1H NMR (300 MHz, CDCl3): d = 5.78 (dd, J = 8.8, 4.9 Hz, 1 H),
5.58 (d large, J = 7.7 Hz, 1 H), 5.24 (dd, J = 8.5, 5.0 Hz, 1 H), 4.35
(d large, J = 6.8 Hz, 1 H), 3.86 (s large, 1 H), 3.72–3.83 (m, 2 H),
3.60–3.72 (m, 2 H), 1.46 (d, J = 6.1 Hz, 3 H), 1.43 (s, 9 H), 1.40–
1.60 (m, 1 H), 0.88 (s, 9 H), 0.86 (s, 9 H), 0.80–0.95 (m, 1 H), 0.07
(s, 6 H), 0.06 (s, 6 H).
To a soln of the preceding diol (0.200 g, 0.29 mmol) in CH2Cl2 (10
mL) at 0 °C were added sequentially Et3N (0.33 mL, 2.33 mmol),
Ac2O (0.11 mL, 1.17 mmol), and DMAP (0.005 g, 0.04 mmol). The
mixture was stirred at 0 °C for 2 h. The same aliquot of each reactant
was added again. The mixture was stirred at 0 °C for a further 2 h.
H2O was added and the aqueous phase was extracted with CH2Cl2
Synthesis 2011, No. 1, 161–167 © Thieme Stuttgart · New York

166
L. Miesch et al.
PAPER
and Et2O. The combined organic extracts were washed with brine,
dried (Na2SO4), and concentrated in vacuo. Purification of the re-
sulting residue by chromatography (silica gel, PE–EtOAc, 95:5)
yielded 11 (0.198 g, 88%) as a yellow oil.
[a]D20 +6 (c 1.0 CHCl3).
IR (CCl4): 1720, 1746, 2051, 1983, 1970, 3448 cm–1.
1H NMR (300 MHz, CDCl3): d = 5.38 (dd, J = 8.3, 4.8 Hz, 1 H),
5.27 (d large, J = 4.9 Hz, 1 H), 5.00 (dd, J = 8.6, 4.8 Hz, 1 H), 4.81
((d, J = 9.9 Hz, 1 H), 4.53 (t, J = 8.5 Hz, 1 H), 4.08 (t large, J = 9.0
Hz, 1 H), 3.86 (q, J = 5.4 Hz, 1 H), dA = 3.57, dB = 3.59 (syst ABX,
JAB = 10.7 Hz, JAX = 5.2 Hz, JBX = 5.4 Hz, Dn = 4.2 Hz, 2 H), 2.12
(s, 3 H), 2.10 (s, 3 H), 1.42 (s, 9 H), 1.39 (d, J = 6.2 Hz, 3 H), 1.05–
1.20 (m, 1 H), 0.80–0.95 (m, 1 H), 0.89 (s, 9 H), 0.85 (s, 9 H), 0.05
(s, 3 H), 0.04 (s, 9 H).
centrated in vacuo. The residue was purified by chromatography
(silica gel, PE–EtOAc, 90:10) to provide 13 (0.134 g, 93%) as a
colorless oil.
[a]D20 +11 (c 1.0 CHCl3).
IR (CCl4): 1725, 1743, 3442 cm–1.
1H NMR (300 MHz, CDCl3): d = 6.20 (dd, J = 15.0, 10.4 Hz, 1 H),
5.97 (dd, J = 15.0, 10.4 Hz, 1 H), 5.71 (qd, J = 15.0, 6.7 Hz, 1 H),
5.43 (dd, J = 15.1, 7.4 Hz, 1 H), 5.30 (t, J = 7.0 Hz, 1 H), 5.10 (t,
J = 4.1 Hz, 1 H), 4.85 (d, J = 9.7 Hz, 1 H), 4.15 (ddd, J = 9.9, 6.4,
3.5 Hz, 1 H), 3.48 (q, J = 5.4 Hz, 1 H), dA = 3.54, dB = 3.60 (syst
ABX, JAB = 10.6 Hz, JAX = 5.5 Hz, JBX = 6.5 Hz, Dn = 17.8 Hz, 2
H), 2.07 (s, 3 H), 2.04 (s, 3 H), 1.73 (d, J = 6.6 Hz, 3 H), 1.42 (s, 9
H), 0.88 (s, 9 H), 0.87 (s, 9 H), 0.04 (s, 12 H).
13C NMR (75 MHz, CDCl3): d = 169.9, 155.5, 135.2, 131.7, 130.6,
124.6, 79.4, 74.5, 72.6, 72.5, 64.3, 52.6, 28.5, 26.0, 26.1, 21.2, 21.3,
18.2, 18.1, 18.4, –5.4, –5.3, –5.0, –4.4.
13C NMR (75 MHz, CDCl3): d = 170.2, 155.4, 85.7, 81.9, 79.5, 75.3,
72.2, 71.7, 64.2, 59.3, 58.3, 54.4, 28.5, 26.0, 26.1, 20.9, 21.1, 19.2,
18.1, 18.4, –5.4, –5.3, –5.1, –4.1.
Anal. Calcd for C31H59O8NSi2: C, 59.10; H, 9.44; N, 2.22. Found:
C, 58.13; H, 8.99; N, 1.79.
Anal. Calcd for C34H59O11NSi2Fe: C, 53.05; H, 7.73; N, 1.82.
Found: C, 53.46; H, 7.62; N, 1.32.
Compound 14
Compound 12
Following the typical procedure for 13, decomplexation of the com-
plex 12 (0.142, 0.18 mmol) with CAN (0.506 g, 0.92 mmol) in
MeOH (7 mL) provided the diene 14 (0.099 g, 85%).
[a]D20 +20 (c 0.9 CHCl3).
Following the typical procedure for the diol precursor to 11, treat-
ment of dienone 9 (0.158 g, 0.23 mmol) with 2 M BH3–Me2S in
THF (0.13 mL, 0.26 mmol) provided the diol (0.130 g, 82%).
[a]D20 +30 (c 0.7 CHCl3).
IR (CCl4): 1728, 1748, 3444 cm–1.
IR (CCl4): 1716, 2047, 1982, 1960, 3400, 3442 cm–1.
1H NMR (300 MHz, CDCl3): d = 6.19 (dd, J = 14.3, 10.5 Hz, 1 H),
5.98 (td, J = 12.8, 1.3 Hz, 1 H), 5.69 (qd, J = 14.8, 6.7 Hz, 1 H), 5.50
(t, J = 7.2 Hz, 1 H), 5.43 (dd, J = 6.5, 2.7 Hz, 1 H), 5.06 (dd, J = 8.8,
2.0 Hz, 1 H), 4.94 (d large, J = 10.4 Hz, 1 H), 4.25 (ddd, J = 10.5,
8.8, 2.6 Hz, 1 H), 3.87 (td, J = 6.7, 1.9 Hz, 1 H), dA = 3.57, dB = 3.63
(syst ABX, JAB = 10.2 Hz, JAX = 6.8 Hz, JBX = 6.6 Hz, Dn = 17.3
Hz, 2 H), 2.03 (s, 3 H), 2.02 (s, 3 H), 1.72 (d, J = 6.4 Hz, 3 H), 1.42
(s, 9 H), 0.91 (s, 9 H), 0.88 (s, 9 H), 0.08 (s, 6 H), 0.06 (s, 3 H), 0.04
(s, 3 H).
1H NMR (300 MHz, CDCl3): d = 5.24 (d large, J = 9.2 Hz, 1 H),
5.15 (dd, J = 8.4, 4.7 Hz, 1 H), 5.04 (dd, J = 8.6, 4.9 Hz, 1 H), 3.90
(s large, 1 H), 3.65–3.89 (s large, 6 H), 2.97 (s large, 1 H), 1.41 (s,
9 H), 1.40 (d, J = 6.4 Hz, 3 H), 1.08–1.16 (m, 1 H), 1.03 (t, J = 8.5
Hz, 1 H), 0.91 (s, 9 H), 0.89 (s, 9 H), 0.11 (s, 3 H), 0.10 (s, 3 H),
0.09 (s, 6 H).
13C NMR (75 MHz, CDCl3): d = 156.0, 86.0, 81.2, 79.4, 77.5, 73.1,
72.4, 66.2, 63.7, 58.2, 55.8, 28.5, 26.0, 26.1, 19.2, 18.3, 18.4, –5.4,
–5.3, –4.4, –3.9.
13C NMR (75 MHz, CDCl3): d = 169.9, 155.2, 134.0, 131.1, 130.8,
125.0, 79.5, 73.7, 72.9, 72.5, 64.2, 51.7, 28.5, 26.0, 26.1, 21.1, 21.2,
18.3, 18.2, 18.4, –5.4, –5.3, –4.7, –4.5.
Anal. Calcd for C30H55O9Si2Fe: C, 52.54; H, 8.08; N, 2.04. Found:
C, 52.68; H, 7.78; N, 1.67.
Anal. Calcd for C31H59O8NSi2: C, 59.10; H, 9.44; N, 2.22. Found:
C, 59.11; H, 9.56; N, 2.21.
Following the typical procedure for 11, the reaction of the diol
(0.130 g, 0.19 mmol) with Et3N (0.21 mL, 1.52 mmol), Ac2O (0.07
mL, 0.76 mmol), and DMAP (0.003 g, 0.03 mmol) yielded 12
(0.142 g, 97%).
Multiprotected Kanosamine 15; Typical Procedure
Diene 13 (0.120 g, 0.19 mmol) in anhyd MeOH (25 mL) was treated
at –78 °C with O3 until the blue color persisted. The excess ozone
was removed by bubbling a stream of argon through the soln, then
Me2S (0.56 mL, 7.62 mmol) was added at –78 °C and the mixture
was stirred at r.t. for 1 h. The soln was concentrated. The residue
was dissolved in EtOAc (15 mL) and washed with H2O (30 mL) and
brine (60 mL). The organic layer was dried (Na2SO4). The soln was
concentrated and the residue was purified by chromatography (sili-
ca gel, PE–EtOAc, 80:20) affording pure multiprotected
kanosamine 15 (0.100 g, 88%) as white crystals.
[a]D20 +29 (c 0.9 CHCl3).
IR (CCl4): 1728, 1749, 2050, 1980, 1970, 3444 cm–1.
1H NMR (300 MHz, CDCl3): d = 5.23 (dd, J = 8.8, 4.8 Hz, 1 H),
5.00 (dd, J = 7.9, 5.7 Hz, 1 H), 4.99 (dd, J = 8.9, 2.1 Hz, 1 H), 4.82
(dd, J = 8.3, 3.0 Hz, 1 H), 4.80 (d large, J = 10.0 Hz, 1 H), 4.34 (td,
J = 9.6, 2.6 Hz, 1 H), 3.88 (td, J = 6.6, 202 Hz, 1 H), dA = 3.56,
dB = 3.58 (syst ABX, JAB = 10.3 Hz, JAX = 7.1 Hz, JBX = 6.6 Hz,
Dn = 6.0 Hz, 2 H), 2.04 (s, 3 H), 2.00 (s, 3 H), 1.40 (s, 9 H), 1.37 (d,
J = 6.2 Hz, 3 H), 0.80–0.97 (m, 1 H), 0.92 (s, 18 H), 0.76 (t, J = 8.6
Hz, 1 H), 0.09 (s, 3 H), 0.07 (s, 3 H), 0.06 (s, 3 H), 0.04 (s, 3 H).
[a]D20 –33 (c 1.0 CHCl3).
IR (CCl4): 1721, 1748, 1758, 3438 cm–1.
13C NMR (75 MHz, CDCl3): d = 169.4, 170.1, 155.0, 85.5, 81.1,
79.6, 74.4, 73.7, 71.7, 64.3, 58.6, 57.9, 53.9, 28.4, 25.9, 26.0, 20.8,
21.2, 19.2, 18.2, 18.4, –5.4, –5.3, –4.6, –4.5.
1H NMR (300 MHz, CDCl3): d = 9.55 (s, 1 H), 5.43 (d, J = 3.7 Hz,
1 H), 5.30 (d large, J = 7.3 Hz, 1 H), 5.25 (t, J = 4.1 Hz, 1 H), 4.61
(ddd, J = 7.9, 3.9, 3.9 Hz, 1 H), 3.96 (q, J = 5.5 Hz, 1 H), dA = 3.59,
dB = 3.61 (syst ABX, JAB = 10.4 Hz, JAX = 4.5 Hz, JBX = 5.9 Hz,
Dn = 4.6 Hz, 2 H), 2.15 (s, 3 H), 2.04 (s, 3 H), 1.42 (s, 9 H), 0.90 (s,
9 H), 0.89 (s, 9 H), 0.08 (s, 3 H), 0.07 (s, 3 H), 0.06 (s, 6 H).
13C NMR (75 MHz, CDCl3): d = 194.8, 169.5, 169.7, 155.5, 80.3,
77.7, 72.3, 72.0, 64.0, 50.3, 28.4, 25.9, 26.0, 20.5, 21.0, 18.1, 18.3,
–5.4, –5.3, –5.1, –4.5.
Compound 13; Typical Procedure
To a soln of complex 11 (0.176 g, 0.23 mmol) in anhyd MeOH (5
mL), a soln of CAN (0.627 g, 1.14 mmol) in MeOH (10 mL) was
added. The mixture was stirred at 0 °C for 20 min and then it was
quenched by addition of sat. aq NaHCO3 (30 mL). The aqueous lay-
er was extracted with EtOAc (30 mL). The organic layer was
washed sequentially with H2O and brine, dried (Na2SO4), and con-
Synthesis 2011, No. 1, 161–167 © Thieme Stuttgart · New York

PAPER
Total Synthesis of Multiprotected Kanosamine
167
Anal. Calcd for C27H53O9NSi2: C, 54.79; H, 9.03; N, 2.37. Found:
C, 54.71; H, 9.05; N, 2.20.
(4) Janiak, A. M.; Milewaki, S. Med. Mycol. 2001, 39, 401.
(5) Frost, J. W.; Guo, J. J. Am. Chem. Soc. 2002, 124, 10642.
(6) Arakawa, K.; Müller, R.; Mahmud, T.; Yu, T. W.; Floss, H.
G. J. Am. Chem. Soc. 2002, 124, 10644.
(7) Peat, S.; Wiggins, L. F. J. Chem. Soc. 1938, 1810.
(8) Pacak, J.; Trnka, T.; Cerny, M. Coll. Czech. Chem. Commun.
1975, 40, 3038.
Multiprotected 3-Amino-3-deoxy-D-altrose 16
Following the typical procedure for 15, treatment of diene 14 (0.099
g, 0.16 mmol) with O3 and Me2S (0.46 mL, 6.29 mmol) led to alde-
hyde 16 (0.084 g, 90%).
(9) (a) Frank-Neumann, M.; Bissinger, P.; Geoffroy, P.
Tetrahedron Lett. 1997, 38, 4473. (b) Frank-Neumann, M.;
Bissinger, P.; Geoffroy, P. Tetrahedron Lett. 1997, 38,
4473. (c) Frank-Neumann, M.; Bissinger, P.; Geoffroy, P.
Tetrahedron Lett. 1997, 38, 4477.
[a]D20 +40 (c 1.0 CHCl3).
IR (CCl4): 1723, 1746, 1753, 3440 cm–1.
1H NMR (300 MHz, CDCl3): d = 9.55 (s, 1 H), 5.33 (d, J = 1.2 Hz,
1 H), 5.17 (dd, J = 8.3, 1.6 Hz, 1 H), 5.10 (dd, J = 9.4, 6.0 Hz, 1 H),
4.90 (td, J = 9.0, 1.1 Hz, 1 H), 3.94 (td, J = 7.2, 1.5 Hz, 1 H),
dA = 3.56, dB = 3.62 (syst ABX, JAB = 10.3 Hz, JAX = 7.9 Hz,
JBX = 6.6 Hz, Dn = 15.5 Hz, 2 H), 2.14 (s, 3 H), 2.04 (s, 3 H), 1.39
(s, 9 H), 0.92 (s, 9 H), 0.91 (s, 9 H), 0.08 (s, 9 H), 0.05 (s, 3 H).
13C NMR (75 MHz, CDCl3): d = 194.6, 169.8, 154.7, 80.3, 78.3,
73.5, 71.9, 64.3, 47.3, 28.3, 25.8, 26.0, 20.5, 21.0, 18.2, 18.3, –5.5,
–5.4, –4.7, –4.6.
(10) Frank-Neumann, M.; Miesch-Gross, L.; Gateau, C. Eur. J.
Org. Chem. 2000, 3693.
(11) Nicolaou, K. C.; Daines, R. A.; Chakraborty, T. K.; Ogawa,
Y. J. Am. Chem. Soc. 1987, 109, 2821.
(12) Saito, S.; Nakajima, H.; Inaba, M.; Morikawe, T.
Tetrahedron Lett. 1989, 30, 837.
(13) Jurczak, J.; Bauer, T.; Chmielewski, M. Carbohyd. Res.
1987, 164, 493.
(14) Makosza, M. In Modern Synthetic Methods; Scheffold, R.,
Ed.; Schweizerischer Chemiker-Verband: Zürich, 1976, 7–
100.
Acknowledgment
Support for this work was provided by CNRS and Université Louis
Pasteur. The authors thank Dr. Jennifer Wytko for assistance in pre-
paring this manuscript.
(15) Frank-Neumann, M.; Miesch-Gross, L.; Gateau, C.
Tetrahedron Lett. 1999, 40, 2829.
(16) Crystallographic data for compound 12 have been deposited
at the Cambridge Crystallographic Data Center (deposition
and no. CCDC-784216). Copies of these data can be
obtained free of charge www.ccdc.cam.ac.uk/data_request/
cif.
(17) Crystallographic data for compound 15 have been deposited
at the Cambridge Crystallographic Data Center (deposition
and no. CCDC-701571). Copies of these data can be
obtained free of charge www.ccdc.cam.ac.uk/data_request/
cif.
References
(1) Cron, M. J.; Johnson, D. L.; Palermiti, F. M.; Perron, Y.;
Taylor, H. D.; Whitehead, D. F.; Hooper, I. R. J. Am. Chem.
Soc. 1958, 80, 752.
(2) Umezawa, S.; Umino, K.; Shibahara, S.; Omoto, S. Bull.
Chem. Soc. Jpn. 1967, 40, 2419.
(3) Milner, J. L.; Silo-Suh, L.; Lee, J. C. Appl. Environ.
Microbiol. 1996, 62, 3061.
Synthesis 2011, No. 1, 161–167 © Thieme Stuttgart · New York