In situ generation of NMO in the osmium-catalyzed dihydroxylation of olefins. Stereoselective oxidation of olefins to cis diols by m-CPBA

Full text of DOI:10.1021/jo981945q

J . Org. Chem. 1999, 64, 2545-2548
2545
In Situ Gen er a tion of NMO in th e
Osm iu m -Ca ta lyzed Dih yd r oxyla tion of
Olefin s. Ster eoselective Oxid a tion of
Olefin s to Cis Diols by m -CP BA
dation has been further developed by Sharpless into a
highly efficient enantioselective process for transforma-
tion of olefins into cis diols.1
3-15
In reactions employing
NMO as the stoichiometric oxidant, the corresponding
amine, N-methylmorpholine (NMM), is formed.
We have for a long time been interested in the in situ
†
†
Katarina Bergstad, J oeri J . N. Piet, and
J an-E. B a¨ ckvall*,‡
generation of oxidants in transition metal-catalyzed
reactions.1
6-23
One objective has been to develop mild
Department of Organic Chemistry, University of Uppsala,
Box 531, SE-751 21 Uppsala, Sweden, and Department of
Organic Chemistry, Arrhenius Laboratory, Stockholm
University, SE-106 91 Stockholm, Sweden
procedures where the in situ generation is carried out
with the aid of a simple oxidant such as molecular oxygen
or hydrogen peroxide. It seemed highly attractive to
regenerate NMO in the osmium-catalyzed dihydroxyla-
tion instead of using the amine N-oxide as a stoichio-
metric reagent. This would be possible if one could find
a way for selective oxidation of the amine NMM in the
presence of other components present in the reaction
media.
Received September 25, 1998
In tr od u ction
There are numerous examples of mild transition metal-
catalyzed oxidations of organic substrates, the osmium-
catalyzed dihydroxylation of olefins being an excellent
Since amines are known to be oxidized easily to their
24
corresponding N-oxides by m-CPBA, we decided to use
1
example of a stereospecific catalytic reaction. The cata-
the latter in model studies of in situ generation of NMO
lytic cis-selective oxidation of olefins to vicinal diols has
been known since 1912 when osmium tetroxide was used
in combination with stoichiometric amounts of metal
chlorates.2 In 1936 Milas found that hydrogen peroxide
(Scheme 1). We now report on an osmium- and NMM-
catalyzed dihydroxylation in which NMM is reoxidized
by m-CPBA (eq 1). To the best of our knowledge, this is
the first example of in situ generation of NMO in the
osmium-catalyzed dihydroxylation of olefins.
,3
can be employed as the terminal oxidant in combination
with catalytic amounts of osmium tetroxide.4
-6
The
stoichiometric reaction was studied by Criegee who
showed that an intermediate osmate ester is formed,
which gives the diol on hydrolysis.7
,8
In the presence of metal chlorates or hydrogen perox-
ide, overoxidation is a commonly encountered problem
resulting in nonselective reactions. Due to these problems
associated with the catalytic procedures, the stoichio-
metric method was for a long time the most reliable way
of transforming olefins to cis-1,2-diols. However, since the
use of large amounts of the osmium reagent is associated
with drawbacks such as high toxicity and cost of the
metal, the search for more efficient catalytic procedures
was continued. Some improvement was obtained with the
use of tert-butyl hydroperoxide (TBHP) as the terminal
oxidizing agent under alkaline conditions.9 A major
breakthrough was realized in 1976 when VanRheenen
demonstrated that N-methylmorpholine N-oxide (NMO)
is a mild and efficient oxidant, which can be used in the
osmium-catalyzed dihydroxylation of olefins without giv-
Resu lts a n d Discu ssion
It is known from previous studies that the use of
certain oxidants such as hydrogen peroxide and tert-butyl
hydroperoxide often results in overoxidized products, e.g.
R-hydroxyketones or compounds derived from C-C bond
cleavage (vide supra).4
,6,9,10
The reported systems all
employ the peroxides as direct oxidants for osmium(VI),
which means that they interact with the intermediate
osmate esters. The use of peracids as direct oxidizing
agents would most likely result in similar problems.
,10
(13) J acobsen, E. N.; Mark o´ , I.; Mungall, W. S.; Schr o¨ der, G.;
Sharpless, K. B. J . Am. Chem. Soc. 1988, 110, 1968.
14) Kolb, H. C.; VanNieuwenhze, M. S.; Sharpless, K. B. Chem.
Rev. 1994, 94, 2483.
(
ing rise to overoxidation of sensitive substrates (the
(15) In 1990, it was discovered that potassium ferricyanide could
be used as a reoxidant for osmium(VI) (see ref 29). Furthermore, it
was realized that this salt was superior to NMO in the asymmetric
dihydroxylation of olefins giving diols with higher ee’s: Kwong, H.-L.;
Sorato, C.; Ogino, Y.; Chen, H.; Sharpless, K. B. Tetrahedron Lett. 1990,
31, 2999.
(16) B a¨ ckvall, J .-E.; Hopkins, R. B.; Grennberg, H.; Mader, M. M.;
Awasthi, A. K. J . Am. Chem. Soc. 1990, 112, 5160.
(17) Grennberg, H.; Gogoll, A.; B a¨ ckvall, J .-E. J . Org. Chem. 1991,
56, 588.
Upjohn procedure).1
1,12
This catalytic stereoselective oxi-
†
University of Uppsala.
‡
University of Stockholm. E-mail: jeb@organ.su.se.
1) Schr o¨ der, M. Chem. Rev. 1980, 80, 187.
(
(
(
2) Hofmann, K. A. Chem. Ber. 1912, 45, 3329.
3) Hofmann, K. A.; Ehrhart, O.; Schneider, O. Chem. Ber. 1913,
4
6, 1657.
(
(
(
4) Milas, N. A.; Sussman, S. J . Am. Chem. Soc. 1936, 58, 1302.
5) Milas, N. A.; Sussman, S. J . Am. Chem. Soc. 1937, 59, 2345.
6) Milas, N. A.; Trepagnier, J . H.; Nolan, J . T.; Iliopulos, M. I. J .
(18) B a¨ ckvall, J .-E.; Chowdhury, R. L.; Karlsson, U. J . Chem. Soc.,
Chem. Commun. 1991, 473.
(19) Grennberg, H.; B a¨ ckvall, J .-E. J . Chem. Soc., Chem. Commun.
1993, 1331.
Am. Chem. Soc. 1959, 81, 4730.
7) Criegee, R. J ustus Liebigs Ann. Chem. 1936, 522, 75.
(20) Grennberg, H.; Faizon, S.; B a¨ ckvall, J .-E. Angew. Chem., Int.
Ed. Engl. 1993, 32, 263.
Chem. 1942, 550, 99.
(21) Wang, G.-Z.; Andreasson, U.; B a¨ ckvall, J .-E. J . Chem. Soc.,
Chem. Commun. 1994, 1037.
(22) Grennberg, H.; Bergstad, K.; B a¨ ckvall, J .-E. J . Mol. Catal. A
1996, 113, 355.
(
(
9) Sharpless, K. B.; Akashi, K. J . Am. Chem. Soc. 1976, 98, 1986.
10) Akashi, K.; Palermo, R. E.; Sharpless, K. B. J . Org. Chem. 1978,
4
3, 2063.
(
11) VanRheenen, V.; Kelly, R. C.; Cha, D. Y. Tetrahedron Lett. 1976,
(23) Bergstad, K.; Grennberg, H.; B a¨ ckvall, J .-E. Organometallics
1998, 17, 45.
1
973.
(
12) VanRheenen, V.; Cha, D. Y.; Hartley, W. M. Organic Synthethes;
(24) Craig, J . C.; Purushothaman, K. K. J . Org. Chem. 1970, 35,
1721.
Wiley: New York, 1988; Collect. Vol. VI, p 342.
1
0.1021/jo981945q CCC: $18.00 © 1999 American Chemical Society
Published on Web 03/18/1999

2
546 J . Org. Chem., Vol. 64, No. 7, 1999
Notes
Sch em e 1. In Situ Gen er a tion of NMO in th e Osm iu m -Ca ta lyzed Dih yd r oxyla tion of Olefin s
Ta ble 1. Cis-Selective Dih yd r oxyla tion of tr a n s-5-Decen e Usin g m -CP BA a s Oxid a n ta
entry
oxidantb
NMM (equiv)
additivesc
reacn time, hd
yield, %e
1
2
3
4
5
6
7
8
9
1.2 equiv of NMO
8
23
28
22
7.5
7
95
13
75
67
37
95
90
80
71
63
47
1.4 equiv of m-CPBA
1.1 equiv of m-CPBA
1.4 equiv of m-CPBA
1.4 equiv of m-CPBA
1.4 equiv of m-CPBA
1.4 equiv of m-CPBA
1.4 equiv of m-CPBA
1.4 equiv of m-CPBA
1.4 equiv of m-CPBA
1.4 equiv of m-CPBA
1.0
0.5
0.25
0.5
0.25
0.20
0.10
0.05
1.3 equiv of TEAA
1.3 equiv of TEAA
1.3 equiv of TEAA
1.3 equiv of TEAA
1.3 equiv of TEAA
1.3 equiv of TEAA
f
7
24
24
24
24
f
f
1
1
0
1
a
trans-5-Decene (1 mmol) was oxidized at room temperature employing 1 mol % OsO4 as catalyst in combination with an oxidant in
b
stoichiometric amounts. A 3:1 mixture of acetone/ H2O was used as solvent. The m-CPBA oxidant was added over 4-5 h, except in entry
3
where NMM is present in equimolar amounts to the peracid. c Tetraethylammonium acetate (TEAA). d The reactions were followed by
GC using n-dodecane as internal standard. Reactions which had reached >90% conversion after a 7 h reaction time were quenched at
this point. Reactions showing 75-90% conversion after 7 h were stirred for an additional 17 h to ensure complete oxidation (except for
e
the reaction reported in entry 5, which was quenched after 7.5 h to make a direct comparison with entry 7 possible). Isolated yields of
1
f
cis diol after flash chromatography. The cis stereochemistry of the product was verified by H NMR. GC analysis showed g 99% of the
cis isomer.
However, trapping of the reactive nonselective oxidant
by NMM under the formation of NMO could possibly be
a way of achieving a selective osmium-catalyzed dihy-
droxylation of olefins (Scheme 1).
formed in the reaction, since diol 1 was only formed in
13% yield (entry 2).26
The oxidation of amines to amine N-oxides by peracids
is known to occur readily.24 However, in the presence of
an olefinic substrate, epoxidation could be a competing
reaction, which would result in contamination of the
desired syn products by either epoxides or anti 1,2-diols.
It was therefore of primary interest to investigate the
kinetics of these two competing oxidations. The rates of
Since oxidation of the amine NMM to NMO by m-
CPBA is a fast reaction (vide supra), we expected that
when NMO was replaced by 1 equiv of NMM together
with an excess of the peracid the reaction would become
almost comparable to that reported in entry 1. The cis
diol was formed as expected but somewhat surprisingly
there was a substantial drop in yield (75% vs 95%; entries
1
the two reactions were studied by H NMR spectroscopy.
NMM was found to be completely oxidized within less
than 5 min,25 whereas epoxidation of trans-5-decene
required almost 3 h to reach 80% conversion. Product
contamination due to epoxidation of the substrate there-
fore seemed to be a minor problem. These results encour-
aged us to further study the in situ formation of NMO
in the osmium-catalyzed dihydroxylation of olefins using
a peracid as the terminal oxidant.
3
and 1). A possible explanation for this result can be
the difference in pH between the two reactions, since in
the reaction reported in entry 3 there is 1 equiv of acid
present in addition to the stoichiometric amount of NMM
,9,10,27
(
vide infra).1
The cis dihydroxylation of trans-5-decene was studied
as a model reaction employing m-CPBA as the stoichio-
metric oxidant in combination with 1 mol % of OsO and
4
A procedure for in situ generation of NMO in the
osmium-catalyzed oxidation would be much more attrac-
tive if the amine could be used in catalytic amounts.
However, when the amount of NMM was decreased to
varying amounts of NMM (eq 2, Table 1). In a control
experiment where the standard conditions for cis-selec-
tive dihydroxylation of olefins were used (i.e., stoichio-
metric NMO), it was demonstrated that trans-5-decene
is a suitable substrate in this model study (entry 1).1
Another control reaction showed that m-CPBA is not a
suitable oxidant for direct oxidation of osmium(VI)
5
0 or 25 mol %, even lower yields were observed (67%
2
8
and 37%, entries 4 and 5, respectively).
1,12
(26) A control experiment showed that a diol, the (1RS,2RS)-1,2-
diphenyl-1,2-ethanediol (2), was stable under these reaction conditions.
The overoxidation products can thus be considered to be formed during
the reactions, and not in subsequent oxidations of the diols.
(
27) Lohray, B. B.; Bhushan, V.; Kumar, R. K. J . Org. Chem. 1994,
59, 1375.
(28) The peracid was added slowly in order to avoid overoxidation.
(
25) The first 1H NMR spectra was taken after 5 min due to practical
reasons such as the time required for locking and shimming.

Notes
J . Org. Chem., Vol. 64, No. 7, 1999 2547
Sch em e 2. P er a cid -Med ia ted Cis Dih yd r oxyla tion
of Olefin s
Sch em e 3. Ster eoselective P r ep a r a tion of Cis
a n d Tr a n s Diols Usin g m -CP BA a s Oxid a n t
oxidation of 1-methyl-1-cyclohexene and 1,2-dihydronaph-
thalene gave cis diols 5 and 6 in 51% and 46% isolated
yields, respectively. In the latter case, 34% of the corre-
sponding R-hydroxyketone was formed as the major
byproduct.3
3,34
The slow step in the osmium cycle is most likely
9
,10,29
hydrolysis of the intermediate osmate ester.
The
lower pH in the reactions involving the in situ generation
of NMO may lead to slower cleavage of this ester,
resulting in less efficient reactions. The hydrolysis
step is described in the literature to be facilitated by
addition of salts such as tetraethylammonium acetate
TEAA).9
,10,27,30
We therefore decided to study the influ-
(
ence of this salt on the NMM-catalyzed dihydroxylation
of trans-5-decene based on m-CPBA as the terminal
oxidant. Addition of TEAA to the reaction mixture did
indeed result in a major improvement of the reaction with
It is interesting to note that a given olefin can now be
converted to either a cis or trans diol in reactions
employing the same oxidant (m-CPBA). Noncatalyzed
oxidation of the substrate followed by aqueous ring
5
(
0 mol % of NMM, giving cis diol 1 in an excellent yield
35-39
opening of an intermediate epoxide
gives the trans
95%, entry 6).3 Having found conditions for an efficient
1
4
diol, whereas the catalytic oxidation (catalytic OsO ,
cis-selective dihydroxylation via in situ generation of
NMO from catalytic amounts of NMM, the apparent next
step was to lower the amount of amine. With 25 mol %
of NMM there was still a high yield (90%, entry 7). With
less than 25 mol % of NMM, the yields dropped (entries
40
catalytic NMM) produces the cis diol (Scheme 3).
To demonstrate that m-CPBA can be used as an
efficient oxidant in stereoselective formation of both cis
and trans diols from olefins, the trans diol 7 was
synthesized from trans-5-decene via epoxidation of the
olefin by m-CPBA followed by acid-catalyzed ring open-
8
-10).
Interestingly, a control experiment showed that in the
presence of TEAA the use of m-CPBA as a direct oxidant
for osmium(VI) (without NMM) gave the diol in 47% yield
41
ing of the isolated epoxide (eq 3). The diastereomeric
syn diol 1 was obtained in excellent yields via cis-selective
oxidation of the same substrate by m-CPBA according
(entry 11). This should be compared to the 13% obtained
to the procedure employing catalytic amounts of OsO
and NMM (Table 1, entry 7).
4
in the absence of TEAA (entry 2).
The conditions for the osmium-catalyzed cis-selective
dihydroxylation employing a peracid as the terminal
oxidant were used for oxidation of several other olefins.
All acyclic substrates, including both trans and cis olefins,
gave the 1,2-diols in good yields in highly stereospecific
cis additions (Scheme 2).
The oxidation of cyclic olefins turned out to be some-
what more troublesome, giving the desired vicinal diols
in only moderate yields. A possible reason for this is that
the cyclic osmate esters of these diols may be more stable
toward hydrolysis than those of the other diols.32 Thus,
(33) The spectroscopic data of the R-hydroxyketone are in accordance
with previously reported data. See: Guertin, K. R.; Chan, T.-H.
Tetrahedron Lett. 1991, 32, 715.
(34) Sharpless has proposed that there may be two major pathways
operating in the dihydroxylation of olefins, a fast primary cycle and a
slow secondary cycle. One way of avoiding the secondary cycle is via
slow addition of the olefin (see: Wai, J . S. M.; Marko, I.; Svendsen, J .
S. Finn, M. G. J acobsen, E. N. Sharpless, K B. J . Am. Chem. Soc. 1989,
111, 1123). Lohray describes the second cycle as the one giving rise to
overoxidation problems in the presence of peroxides as terminal
oxidants (see ref 27). In an attempt to increase the ratio of diol/R-
hydoxyketone formed in the oxidation of 1,2-dihydronaphthalene, the
olefin was added slowly. However, no improvement was observed in
the oxidation of this seemingly sensitive substrate.
(
35) Swern, D. Org. React. 1953, 7, 378.
(
29) Minato, M.; Yamamoto, K.; Tsuji, J . J . Org. Chem. 1990, 55,
66.
30) The rate increase observed in the presence of this salt is
(36) Gorzynski Smith, J . Synthesis 1984, 629.
(37) Rao, A. S. Tetrahedron 1983, 39, 2323.
(38) Fringuelli, F.; Germani, R.; Pizzo, F.; Savelli, G. Synth. Com-
mun. 1989, 19, 1939.
7
(
sometimes referred to as an effect of an added base, and sometimes
as a result of addition of an extra nucleophile. See refs 9, 10, and 27.
(39) Trans diols can also be formed in base-catalyzed ring opening
of epoxides. However, these reactions often require harsher conditions
compared to the mild acid-catalyzed epoxide opening. See ref 38.
(40) There are some procedures reported in the literature for
stereoselective formation of either cis or trans diols from olefins by
the use of the same reagents. In the Pr e´ vost reaction (dry conditions)
a trans diol will be formed, whereas in the Woodward reaction (wet
conditions) the product is a diol with cis stereochemistry. See the
following references. Wilson, C. V. Org. React. 1957, 9, 332. Haines,
A. H. Addition Reactions with Formation of Carbon-Oxygen Bonds:
(iii) Glycol Forming Reactions in Comprehensive Organic Chemistry,
Vol. 7; Trost, B. M., Fleming, I., Eds.; Pergamon Press: Oxford, U.K.,
1991;, pp 437-448.
2 3
(31) In a control experiment TEAA was replaced by K CO (1.3
equiv). Since the diol 1 was formed in 72% isolated yield, compared to
the 37% in the reaction reported in Table 1, entry 5, it can be concluded
that the presence of base is necessary for efficient reactions. Somewhat
surprisingly the addition of MeSO NH , which is commonly used for
2 2
similar purposes, did not have any effect under the reaction conditions
employed in this work.
(32) Tri- and tetrasubstituted olefins are known to react only slowly
in the osmium-catalyzed dihydroxylation due to a slow hydrolysis of
the osmate ester. Moreover, the osmate ester from cholesterol is
extremely unreactive toward hydrolysis due to steric reasons and has
been used as a model substrate to test the efficiency when modified
procedures for the osmium-catalyzed dihydroxylation have been
developed. See refs 1, 9, and 10.
(41) Fieser, L. F.; Fieser, M. Reagents for Organic Synthesis;
Wiley: New York, 1967, Vol. 1, p 796.

2
548 J . Org. Chem., Vol. 64, No. 7, 1999
Notes
stirring at room temperature, the mixture was filtered over
Celite, and the Celite was subsequently rinsed with EtOAc (75
mL). The aqueous phase was extracted with EtOAc (4 × 12 mL),
and the combined organic phases were washed with 2 M NaOH
(
2 × 10 mL). The organic phase was dried (MgSO
4
) and
concentrated in a vacuum to give the crude diol 1. The crude
product was purified by column chromatography (50:50 pentane/
Et
data were in accordance with previously reported data.
1RS,2RS)-1,2-Dip h en yl-1,2-Eth a n ed iol (2). The same pro-
2
O) to yield 1 as a white solid (157 mg, 90%, g99% cis). NMR
4
2
(
Con clu sion
cedure as above afforded 2 as a white solid (177 mg, 83%, g
99% cis). NMR data were in accordance with previously reported
data.4
From an economical and environmental point of view,
3,44
m-CPBA may not be of any major advantage over
stoichiometric amounts of NMO. However, the main
purpose with this paper has been to demonstrate the
principle that NMO can be regenerated in situ in the
osmium-catalyzed dihydroxylation rather than to develop
a new synthetic procedure for dihydroxylation. A major
problem in realizing such a process has been that the
rate of the cleavage of the osmate ester decreases when
catalytic amounts of NMM/NMO are employed. This
problem was solved by addition of tetraethylammonium
acetate. One advantage with the in situ generation of
NMO is that specifically designed N-oxides can be used,
which should be synthetically useful. We will now try to
extend the in situ generation of NMO in the osmium-
catalyzed dihydroxylation of olefins to other oxidants
such as hydrogen peroxide and molecular oxygen.
(
1RS,2RS)-1-P h en yl-1,2-p r op a n ed iol (3). The same pro-
cedure as above, except for the use of solid tetraethylammonium
acetate (0.53 g, 2.03 mmol), afforded 3 as a white solid (116 mg,
6%, g 99% cis). NMR data were in accordance with previously
reported data.
(1RS,2SR)-1,2-Dip h en yl-1,2-eth a n ed iol (m eso) (4). The
same procedure as above afforded 4 as a white solid (162 mg,
6%, g 99% cis). NMR data were in accordance with previously
7
4
5
7
4
6
reported data.
cis-1-Meth yl-1,2-cycloh exa n ed iol (5). The same procedure
as above, except for a 15 h reaction time after complete addition
of the oxidant and saturation of the aqueous phase with NaCl
(s) before extraction with EtOAc, afforded 5 as a white solid (66
mg, 51%, g99% cis). NMR data were in accordance with
previously reported data.47
cis-1,2,3,4-Tetr a h yd r o-1,2-n a p h th a len ed iol (6). A solution
of m-CPBA (480 mg, 50-60%, ca. 1.4 mmol) in acetone (1.5 mL)
2
and H O (0.5 mL) was added slowly over 12 h to a mixture of
1
,2-dihydronaphthalene (130 µL, 1.00 mmol), tetraethylammo-
nium acetate (0.53 g, 2.03 mmol), N-methylmorpholine (28 µL,
0
acetone (2.3 mL), and H O (0.7 mL). The mixture was stirred
Exp er im en ta l Section
t
4
.25 mmol), OsO (120 µL, 2.5 wt % in BuOH, 0.01 mmol),
Gen er a l P r oced u r es. 1H and 13C NMR spectra were re-
corded at 400 and 100.6 MHz, or 200 and 50.3 MHz, respectively.
Chemical shifts (δ) are reported in ppm, using residual solvent
as internal standard. Most reagents were purchased from
Lancaster except for N-methylmorpholine (Fluka), N-methyl-
morpholine N-oxide (Aldrich), trans-â-methylstyrene (Aldrich),
m-CBPA (50-60%, Aldrich), and 1-methyl-1-cyclohexene (TCI
2
for an additional 12 h. Purification of the crude product (gradient
50:50 pentane/ Et O to 100% Et O) gave 6 as a white solid (75
2
2
mg, 46%, g98% cis). NMR data were in accordance with
previously reported data.48
Ackn owledgm en t. Financial support from the Swed-
ish Research Council for Engineering Sciences and the
Swedish Natural Science Research Council is gratefully
acknowledged. Ms. Sandra J onsson is greatly acknowl-
edged for assistance with GC analyses.
t
Kasei). OsO
4
was purchased as a 2.5 wt % solution in BuOH
(Aldrich). Tetraethylammonium acetate (TEAA) was acquired
from Aldrich (99%) or Lancaster (50% aqueous solution). Com-
mercial chemicals were used as received without further puri-
fication. The products were purified by chromatography on silica
gel (Merck silica gel 60, 230-400 mesh). Progress of the reaction
was followed by TLC on Merck silica gel 60 F254 plates, or by
GC using a SE 54 column (25m, 250 µm) with n-dodecane as
internal standard. A syringe pump Sage model 355 was used
for slow additions. For all substrates used, cis diols were
prepared as reference compounds by the osmium-catalyzed
dihydroxylation using NMO as stoichiometric oxidant (see
Supporting Information for details). Trans diols were synthe-
sized via epoxidation of the olefins followed by acid- or base-
catalyzed opening of the epoxides (see Supporting Information
Su p p or tin g In for m a tion Ava ila ble: Experimental de-
tails for synthesis of cis diols 1-6 via a general procedure
employing NMO as stoichiometric oxidant, synthesis of trans-
5-decene oxide, trans-stilbene oxide, and 1,2-dihydronaphtha-
lene oxide via epoxidation of the corresponding olefins, and
synthesis of trans-1,2-diols from trans-5-decene (i.e. 7), trans-
stilbene (i.e. 4), 1,2-dihydronaphthalene, 1-methyl-1-cyclohex-
ene, and trans-â-methylstyrene via acid- or base-catalyzed
opening of the corresponding epoxides. This material is avail-
able free of charge via the Internet at http://pubs.acs.org.
for details). All the trans and cis diols separated on either 1
H
NMR (all prepared diols) or GC (DBWAX-5 column, 30 m, 320
µm; 5,6-decanediol and 1-methyl-1,2-cyclohexanediol).
Gen er a l P r oced u r e for P r ep a r a tion of Cis Diols fr om
Olefin s w it h In Sit u F or m a t ion of NMO. (5RS,6RS)-5,6-
Deca n ed iol (1). trans-5-Decene (190 µL, 1.00 mmol) was
dissolved in acetone (2.3 mL). To this mixture were added
tetraethylammonium acetate (0.7 g, 50% aqueous solution, 1.3
J O981945Q
(
42) Tanner, D.; Birgersson, C.; Gogoll, A.; Luthman, K. Tetrahedron
1
994, 50, 9797.
(
(
43) Wang, Z.-M.; Sharpless, K. B. J . Org. Chem. 1994, 59, 8302.
44) Nymann, K.; J ensen, L.; Svendsen, J . S. Acta Chem. Scand.
1996, 50, 832.
(45) Pedragosa-Moreau, S.; Archelas, A.; Furstoss, R. Tetrahedron
996, 52, 4593.
1
mmol), N-methylmorpholine (28 µL, 0.25 mmol), and OsO
4
(120
µL, 2.5 wt % in BuOH, 0.01 mmol). A solution of m-CPBA (480
mg, 50-60%, ca. 1.4 mmol) in acetone (1.5 mL) and H O (0.5
mL) was added slowly over 4 h. The mixture was stirred for an
additional 3 h and then quenched by addition of Na (0.8
g) and magnesium silicate (0.5 g) in H O (0.8 mL). After 2 h of
t
(46) Corriu, R. J . P.; Lanneau, G. F.; Yu, Z. Tetrahedron 1993, 49,
019.
9
2
(47) Tamura, Y.; Annoura, H.; Kondo, H.; Fuji, M.; Yoshida, T.;
Fujioka, H. Chem. Pharm. Bull. 1997, 35, 22305.
(48) Naemura, K.; Wakebe, T.; Hirose, K.; Tobe, Y. Tetrahedron:
Asymmetry 1997, 8, 2585.
2
2 4
S O
2