The facile preparation of alkenyl metathesis synthons

Article abstract of DOI:10.1016/j.tet.2004.09.021

We report synthetic methodology allowing the preparation of any length alkenyl halide from inexpensive starting reagents. Standard organic transformations were used to prepare straight chain α-olefin halides in excellent overall yields with no detectable olefin isomerization and full recovery of any unreacted starting material. Reported transformations can be used for the selective incorporation of pure α-olefin metathesis sites in highly functionalized molecules.

Full text of DOI:10.1016/j.tet.2004.09.021

Tetrahedron 60 (2004) 10943–10948
The facile preparation of alkenyl metathesis synthons
*
Travis W. Baughman, John C. Sworen and Kenneth B. Wagener
The George and Josephine Butler Polymer Research Laboratory, Department of Chemistry, University of Florida, PO Box 117200,
Gainesville, FL 32605, USA
Received 27 April 2004; revised 3 September 2004; accepted 9 September 2004
Available online 1 October 2004
Dedicated to Professor Robert H. Grubbs on the occasion of his receiving the Tetrahedron Prize for Creativity in Organic Chemistry
Abstract—We report synthetic methodology allowing the preparation of any length alkenyl halide from inexpensive starting reagents.
Standard organic transformations were used to prepare straight chain a-olefin halides in excellent overall yields with no detectable olefin
isomerization and full recovery of any unreacted starting material. Reported transformations can be used for the selective incorporation of
pure a-olefin metathesis sites in highly functionalized molecules.
q 2004 Elsevier Ltd. All rights reserved.
1. Introduction
total synthesis.15 In addition, advances in CM and the
understanding of olefin reactivity have stimulated the
development of complex synthetic schemes where two or
more olefins can be reacted regio- and stereoselectively
forming only the target olefin in excellent yields.16 Acyclic
diene metathesis (ADMET), a special form of CM yielding
polymers, has been used in materials synthesis and
industrial polymer modeling.2 This rapid rise in olefin
metathesis popularity, utility, and catalyst improvement has
generated the need for inexpensive, high yielding a-olefin
constructs and the means of incorporating metathesis sites
into various complex architectures.
Olefin metathesis has emerged as one of the primary
methods for mild carbon–carbon bond formation in organic
synthesis, having been widely used across many areas of
chemical research. Functional group tolerant ruthenium
based catalysts permit the metathesis of highly functiona-
lized compounds that were previously incompatible with
traditional catalysts.1 The development of these stable and
reactive catalysts, such as Grubbs’ second-generation
complex, has expanded metathesis’ utility in polymer
chemistry2,3 and more recently in small molecule syn-
thesis.4–8 Difficult cross-metathesis and ring-closing
metathesis reactions can now be accomplished allowing
access to large ring systems9 and functionalized polymer
architectures.10 The application of efficient and mild
transformations such as ring closing metathesis (RCM),11
ring opening metathesis (ROM),12 and cross-metathesis
(CM) has led to pervasive use of olefin metathesis in small
molecule and polymer chemistry.13
We now report three facile and inexpensive synthetic routes
to a family of pure a-alkenyl halide metathesis synthons
possessing exact methylene run lengths. These synthetic
procedures and routine purification methods afford high
yields of olefins with no detectable double bond isomeriza-
tion. The mild transformations reported can also be used to
place olefins in highly functionalized molecules without the
need for expensive starting materials.
In general, RCM is valuable for selective and efficient ring
closures of large functionalized natural products and
supramolecularly organized substrates.14 Application of
ROM in combination with CM effectively produces
complex ring-opened cross-metathesis products from the
coupling of cyclic and linear olefins; this method has been
used to connect large molecules and is readily applied in
2. Results and discussion
Metathesis ideology has fueled the development of next
generation catalyst systems for the production of specific,
highly functionalized target molecules for medical and
consumer use. Consequently, a large scale, high-yielding
a-olefin synthesis is needed to produce molecules for
subsequent substitution and metathesis chemistry. Before
any metathesis can occur, olefins must be incorporated into
substrates where mild and inexpensive techniques would be
Keywords: a-Olefin; Cross-metathesis; Alkenyl halide; ADMET;
Metathesis.
* Corresponding author. Tel.: C1 352 392 4666; fax: C1 352 392 9741;
e-mail: wagener@chem.ufl.edu
0040–4020/$ - see front matter q 2004 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tet.2004.09.021

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T. W. Baughman et al. / Tetrahedron 60 (2004) 10943–10948
preferred for the creation of target olefins. While well-
known literature techniques yield a-olefins directly or
transform complex substrates into metathesis active com-
pounds, unwanted side reactions occur leading to low
yields.17,18 This makes recovery of pure starting materials
difficult and expensive, while reaction products are
sometimes extensively isomerized. These are common
problems associated with a-olefin synthesis, and they
often lead to structural defects when isomerized olefins
are used in metathesis transformations.
can be regarded as metathesis synthons in ADMET, cross-
metathesis, and RCM chemistry (Scheme 1).
We have devised two routes to these synthons; the
preparation of pure a,u-alkenyl halides was performed
either by the reduction of alkenyl esters or through the
elimination of HBr from alkyl dibromides. Both routes are
described herein, along with a procedure to generate long
chain a-alkenyl halide synthons.
2.1. Alkenyl halide metathesis synthons from alkenyl
esters
Metathesis strategy in small molecule modification typi-
cally targets one specific regio- and stereoselective attach-
ment of functionality to produce a high yield of a single
molecule. While this facet of synthesis is important,
controlling the number of methylene units between olefins
is paramount when targeting specific ring size or exact
structure. With this in mind, acyclic diene metathesis
(ADMET) polymerization of symmetrical a,u-diene mono-
mers and ROMP of symmetrical cyclic olefins have become
the polymerization methods of choice for the preparation of
polymers with exact repeat units.
The key to success in generating ADMET, cross-metathesis
and RCM dienes is found in locating a source of pure
a-alkenyl halide bulk starting materials. Numerous sources
of such starting materials exist based on alkenyl esters
derived from fatty acids with no isomerization of the
pendent olefin. These molecules can be easily reduced to
their corresponding alcohols, and literature describing the
reduction of various alkenyl esters extends to the 1940s
including LAH reactions,20–23 titanium mediated reductions
of esters,24,25 and polymethylhydrosilane reductions.26 We
have chosen the inexpensive conversion of an a-olefin ester
or carboxylate to an alcohol using LAH in THF (Scheme 2).
This method was chosen specifically for the reduction of
4-pentenyl ester as the byproduct ethanol could be easily
removed via rotary evaporation.
Substrate purity for metathesis reactions is essential, as
structural flaws lead to low yielding ring closures, the
isolation of the wrong metathesis products, or ill-defined
polymer microstructure. Inclusion of internal and external
olefins as starting materials in metathesis poses problems as
methylene run lengths within product structure will be
varied based on extent of olefin isomerization. In the case of
small molecule synthesis, variable methylene content in the
substrate yields different ring-sizes for RCM or incorrect
methylene run lengths for ROM or CM reactions
(Scheme 1). The inclusion of isomerized olefins in starting
material synthesis creates ill-defined structures leading to
numerous olefinic products.
These inexpensive reactions were done on the 100-gram
scale in a large flask with sufficient volume for post reaction
workup. Upon product isolation, compounds 1 and 2 were
characterized via 1H NMR and GC with no detectable olefin
isomerization and above 90% purity. Both alkenyl alcohols
were clean enough to move onto the next transformation
without any further purification.
The construction of ADMET monomers and isolation of
exact polymer structures begins with the synthesis of pure
a-olefins. Errors due to inclusion of isomerized olefinsduring
polymer synthesis become multiplied with high olefin
turnover, and ultimately these errors produce random
polymer structures and ill-defined methylene run lengths
between functional groups. These defects are detrimental for
polymer modeling studies and lead to poor material proper-
ties relative to polymers obtained from purely a-olefins.19
We have addressed these problems starting with the
inexpensive synthesis of 1-alkenyl bromides, reagents that
Conversion of these alkenyl alcohols to corresponding
bromides was done using carbon tetrabromide and triphenyl
phosphine. This reaction appears to be the most efficient
route when considering all reasonable possibilities includ-
ing the use of phosphorus tribromide,27 bromine,28 trifluoro
aceticanhydride,29 and various other conversions that first
convert the alcohol to a good leaving group such as a
mesylate30,31 or a silyl ether.32 The bromination with CBr4
proceeded quickly and was complete almost as fast as all
components could be mixed. The byproduct acid,
Scheme 1. Cross-metathesis, ring closing metathesis and the ADMET reaction.

T. W. Baughman et al. / Tetrahedron 60 (2004) 10943–10948
10945
Scheme 2. Alkenyl halide synthesis.
bromoform, does not isomerize the olefin and allows for
isolation of clean a-olefin in good yields.
this conversion (150 8C) can result in olefin isomerization in
addition to halide elimination. One other disadvantage to
this elimination chemistry is the inability to recover
unreacted starting material from the complex reaction
mixture. Recently, a potassium butoxide elimination has
been reported affording alkenyl halides in good yield.34
A milder, higher yielding room temperature route is
presented in Scheme 3.
Synthesis of chlorine-functionalized a-olefins has been
previously reported and is usually performed neat via
addition of SOCl2 to the liquid alcohol.21–23 We performed
this conversion by adding the SOCl2 to a solution of alkenyl
alcohol 2 in pyridine acting as a solvent and an acid trap.
Upon vacuum distillation, the alkenyl chloride 5 was
obtained in good yield. Conversion of the chloride to the
alkenyl iodide was performed by a Finkelstein reaction with
sodium iodide in acetone.33
Simple KOtBu driven elimination in a THF/toluene solvent
mixture produces the target molecules in w65% yield. This
elimination reaction is started at 0 8C and is allowed to
warm to room temperature over 1 h. Upon quenching with
aqueous acid, the dibromide/alkenyl bromide mixture can
be easily purified affording the target molecule. The
recovered dibromide can be recycled for further conversion
to alkenyl bromide as necessary.
2.2. Alkenyl halide metathesis synthons via selective
dihalide elimination
A method of olefin incorporation within molecules was
desired in addition to the production of inexpensive starting
reagents for metathesis synthesis. Mild elimination
conditions were developed allowing a second method of
a-olefin production that could also permit olefin incorpor-
ation in functionalized molecules where application of
substitution chemistry is unavailable. Literature methods
designed to prepare alkenes and alkenyl halides involve the
elimination of bromo and dibromo alkanes using hexa-
methylphophortriamide (HMPT).17,18 This route is expensive
and potentially dangerous due to the highly carcinogenic
compound HMPT. Harsh conditions and the highly reactive
HMPT lead to a myriad of byproducts that interfere with
purification and further, the high temperatures needed for
2.3. Synthesis of larger alkenyl bromide metathesis
synthons
Up to this point, the incorporation of metathesis sites into
target molecules has been limited by commercial avail-
ability and expense of alkenyl bromides. This is especially
true when considering the preparation of longer chain
alkenyl bromides, a problem that has been overcome by
exploiting and extending the chemistry described in the
previous sections. As an example of this strategy, we
synthesized an alkenyl bromide containing 20 carbons, a
molecule which is commercially unavailable.
The synthesis of extended alkenyl bromides began with the
self-metathesis of 4 with Grubbs’ first generation catalyst to
afford 7 (Scheme 4). This dibromide was converted to 8 by
exhaustive hydrogenation in a Parr bomb with Wilkinson’s
Rh catalyst under hydrogen pressure. The saturated
20-carbon dibromide 8 was then converted to the target
Scheme 3. A mild elimination route towards the synthesis of alkenyl
bromide metathesis synthons.
Scheme 4. The preparation of long chain alkenyl bromide metathesis synthons.

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T. W. Baughman et al. / Tetrahedron 60 (2004) 10943–10948
extended chain alkenyl bromide 9 using the same elimin-
ation procedure previously described for smaller alkenyl
bromides. Pure compound 9 was obtained in good yield
after recrystallization and column chromatography, and
recovery of the pure starting reagents was accomplished
during purification since very few side reactions accompany
these mild transformations.
obtained in 85% yield and 97% purity by GC. The 1H NMR
spectrum was consistent with the published spectrum.36
4.3.2. 10-Undecene-1-ol (2). Zinc undecylenate (250 g,
0.579 mol) was added over 30 min via powder funnel to a
stirred slurry of LAH (25.0 g, 0.659 mol) in dry THF
(400 mL) in a 5 L round bottom flask at 0 8C. After the
addition, the solution was allowed to warm to room
temperature over 1 h while stirring. The reaction was
quenched via addition of deionized water (25 mL), 15%
(w/v) NaOH (25 mL), and more water (75 mL) waiting
approximately 15 min between additions. The solution was
allowed to stir until cool, and the reaction mix appeared as a
white slurry. All precipitate was filtered, and the solution
was concentrated to a turbid oil. The crude mixture was
dissolved in ether (100%, v/v) and stirred over MgSO4
(15 g) for 45 min. The solution was filtered and concen-
trated to afford compound 2 as a colorless oil in 87% yield
3. Conclusions
Three mild, inexpensive routes have been devised for the
production of pure a-olefin containing halides as metathesis
synthons. Using these methods, virtually any 1-alkenyl
bromide can be made in high yields and devoid of olefin
isomerization. Many of the reactions discussed here are
either quantitative in nature, or the starting reagent can be
easily recovered for further use.
1
(97% pure by GC). The H NMR spectrum was consistent
with the published spectrum.24
4. Experimental
4.4. Synthesis of alkenyl halides from alkenyl alcohols
4.1. General information
4.4.1. 5-Bromo-1-pentene (3). A solution of 1 (100 g,
1.16 mol) and carbon tetratbromide (424 g, 1.27 mol) in
dichloromethane (500 mL) was prepared in a 2 L flask and
cooled to 0 8C. Triphenyl phosphine (333 g, 1.28 mol) was
added via powder funnel in portions over 30 min with
vigorous stirring. Upon addition of the phosphine, the
colorless solution turned a pale brown color and was stirred
for an additional 2 h at room temperature. The mixture was
concentrated to a brown oil and quickly added to stirring
hexane (1 L). The white precipitate was filtered, and the
remaining solution was concentrated and fractionally
distilled yielding compound 3 as a colorless oil (80%).
1
All H NMR (300 MHz) and 13C NMR (75 MHz) spectra
were recorded in CDCl3 on a Varian Associates Mercury
300 spectrometer. Chemical shifts are given in ppm and
referenced to residual CHCl3 at 7.27 ppm (1H) and
77.23 ppm (13C) with 0.03 v/v% TMS as an internal
standard. Splitting patterns are designated s, singlet; d,
doublet; t, triplet; m, multiplet; br, broad. Gas chromato-
graphy was performed on a Shimadzu GC-17A chromato-
graph equipped with a RTX-5 (Restek Corp.) 15 m column
and a HP-5 (Hewlett Packard) 25 m column with FID
detection. Compounds were examined using mass spec-
trometry performed by The University of Florida Mass
Spectrometry Services and elemental analysis performed by
Atlantic Microlabs (Norcross, GA).
1
The H NMR spectrum was consistent with the published
spectrum.37
4.4.2. 11-Bromo-1-undecene (4). Using the procedure
outlined for compound 3 (above), bromide 4 was prepared
using alcohol 2 (150 g, 0.881 mol), carbon tetrabromide
(323 g, 0.976 mol), triphenyl phosphine (255 g, 0.976 mol),
and 800 mL of dichloromethane. Fractional distillation
4.2. Materials
All starting materials were purchased from Aldrich except
for acetic acid 4-pentenyl ester, which was supplied by TCI
America. Grubbs’ first generation [Ru] catalyst was
synthesized as previously described by Grubbs et al.35 Dry
solvents were collected using an Aldrich keg system
removing residual water by alumina filtration.
1
yielded compound 4 as a colorless liquid (95%). The H
NMR spectrum was consistent with the published
spectrum.28
4.4.3. 11-Chloro-1-undecene (5). In an argon purged 3 L
round bottom flask, distilled thionyl chloride (259 g,
2.17 mol) was added dropwise over 1 h via cannula into a
solution of 2 (200 g, 1.28 mol) in pyridine (50 mL). Upon
compete addition, the reaction was heated to 50 8C for 2 h,
cooled, and quenched via the addition of water (300 mL)
and diethyl ether (300 mL) letting stir for 1 h. The
remaining mixture was extracted, and the organic phase
was washed with saturated NaHCO3 (2!150 mL) and
distilled water (100 mL). The solution was dried over
MgSO4, concentrated, and vacuum distilled to a colorless
oil 5 (70%). The 1H NMR spectrum was consistent with the
published spectrum.38
4.3. Synthesis of alkenyl alcohols
4.3.1. 4-Pentene-1-ol (1). Acetic acid pent-4-enyl ester
(250 mL, 1.77 mol) was added dropwise over 2 h to a slurry
of LAH (23.7 g, 0.625 mol) in diethyl ether (500 mL) at
0 8C. The solution was allowed to warm to room
temperature over 1 h while stirring. The reaction was
quenched via the sequential addition of 23 mL deionized
water (23 mL), 15% (w/v) NaOH (23 mL), and deionized
water (69 mL) waiting approximately 5 min between
additions. The solution was allowed to stir the mixture
became a bright white slurry. Additional ether (w125 mL)
was added and the solution was filtered, dried over MgSO4,
and concentrated to a colorless oil. Compound 1 was
4.4.4. 11-Iodo-1-undecene (6). Sodium iodide (40.7 g,
0.271 mol) was added to distilled 5 (30.6 g, 0.162 mol) in

T. W. Baughman et al. / Tetrahedron 60 (2004) 10943–10948
10947
acetone (150 mL) and allowed to reflux for 3 days. The
reaction mixture was then cooled and flooded with ether
(300 mL). The precipitate was filtered and the ether solution
was washed with water (2!100 mL). The organic layer was
extracted, dried with MgSO4, filtered, and concentrated to a
colorless oil 6 (89%). The 1H NMR spectrum was consistent
with the published spectrum.39
THF/toluene mixture producing a 1 M solution. The
mixture was cooled using an ice water bath, and potassium
tert-butoxide (19.0 g, 170 mmol) was added in 2 g portions
over 30 min. After addition, the reaction turned cloudy and
was allowed to stir at 0 8C for 1 h. The reaction was
quenched using water (100 mL) followed by 1 M HCl
(100 mL). The organic layer was extracted and washed with
1 M HCl (50 mL), saturated Na2CO3 (50 mL), and 50 mL of
water followed by drying with magnesium sulfate. The
solution was concentrated yielding 38 g of crude material.
Compound 9 was purified by room temperature recrystalli-
zation from 1-butanol (5 w/v%) followed by column
chromatography using hexane. Compound 9 was collected
as white solid. Yield: 24 g (60%). The following spectral
properties were observed: 1H NMR (CDCl3): d (ppm)
1.20–1.50 (br, 30H), 1.88 (q, 2H, JZ7.2 Hz, CH2CH2Br),
2.01 (q, 2H, allylic CH2), 3.42 (t, 2H, JZ6.9 Hz, CH2Br),
5.09 (m, 2H, RHC]CH2), 5.76 (m, 1H, RHC]CH2); 13C
NMR (CDCl3): d (ppm) 28.4, 29.3, 29.7, 29.8, 32.8, 33.1,
34.4, 114.3, 139.4; EI/HRMS: [M]C calcd for C20H39Br:
358.2235, found: 358.2246.
4.5. Synthesis of alkenyl bromides from dibromides
4.5.1. 5-Bromo-1-pentene (3). In a 1 L round bottom flask
1,5-dibromopentane (100 g, 0.434 mol) was dissolved in
450 mL of a 1:1 THF/toluene solution to favor the single
eliminated product. The flask was cooled to 0 8C followed
by the addition of solid KOtBu (73.0 g, 0.651 mol) over
30 min. After addition, the reaction was quenched using
1 M HCl (300 mL) and the organic layer was extracted,
washed with saturated Na2CO3 (100 mL), and dried over
magnesium sulfate. The solution was concentrated and
distilled yielding 44 g of compound 3 (69%). The 1H NMR
spectrum was consistent with the published spectrum.37
4.5.2. 1,20-Dibromo-eicos-10-ene (7). In an argon filled
glove box, compound 4 (100 g, 429 mmol) was added to a
500 mL round bottom flask followed by Grubbs’ catalyst
(706 mg, 0.885 mmol, 500:1). The flask was heated at 35 8C
for 24 h under a constant stream of argon. After 1 day, the
flask was placed under vacuum (10 Torr) for an additional
48 h, cooled, and quenched with ethyl vinyl ether (5 mL).
The crude reaction mixture was dissolved in toluene
(200 mL) and precipitated into methanol (1000%, v/v)
over the course of 30 min. The product was filtered as a
white crystalline solid and washed with excess methanol
yielding 75 g (80%). The following spectral properties were
Acknowledgements
We would like to thank NSF, ARO, and the NASA Space
Grant Consortium for funding. We would also like to thank
and Timothy Hopkins and Ed Lehman for advice and
synthetic work.
References and notes
1
observed: H NMR (CDCl3): d (ppm) 1.20–1.50 (br, 24H),
1. Buchmeiser, M. R. Chem. Rev. 2000, 100, 1565–1604.
2. Lehman, S. E.; Wagener, K. B. Grubbs, R. H., Ed.; 1st ed.;
Handbook of Metathesis; Wiley-VCH Verlag GmbH:
Weinheim, 2003; Vol. 3, pp 283–347.
1.88 (q, 4H, J1Z7.0 Hz, J2Z7.0 Hz, CH2CH2Br), 2.01
(m, 4H, allylic CH2), 3.42 (t, 4H, JZ6.7 Hz, CH2Br), 5.40
(m, 2H, olefin); 13C NMR (CDCl3): d (ppm) 28.4, 29.3,
29.7, 29.8, 32.8, 33.1, 34.4, 130.3; EI/HRMS: [M]C calcd
for C20H38Br2: 438.1322, found: 438.1312.
3. Black, G.; Maher, D.; Risse, W. Grubbs, R. H., Ed.; 1st ed.;
Handbook of Metathesis; Wiley-WCH Verlag GmbH:
Weinheim, 2003; Vol. 3, pp 2–66.
4.5.3. 1,20-Dibromo-eicosane (8). In a 125 mL Parr bomb
glass sleeve, compound 7 (35 g, 80 mmol) was dissolved in
a minimal amount of toluene (w80 mL). Wilkinson’s Rh
hydrogenation catalyst (100 mg, 0.104 mmol) was added,
and the bomb was charged with 800 psi of hydrogen. The
reaction was allowed to proceed for 24 h at 50 8C.
Additional toluene (200 mL) was added, and upon cooling
to 0 8C, the product 8 crystallized out of solution and was
collected by filtration. The filtrate was concentrated
(w50%), and the product was allowed to crystallize
again. Upon isolation of the product from the second
crystallization, both portions were combined and washed
with cold toluene. Yield: 30 g (86%). The following spectral
4. Harned, A. M.; Mukherjee, S.; Flynn, D. L.; Hanson, P. R.
Org. Lett. 2003, 5, 15.
5. Wright, D. L. Curr. Org. Chem. 1999, 3, 211.
6. Fang, Z.; Hong, J. H. Org. Lett. 2004, 6, 993–995.
7. Theeraladanon, C.; Arisawa, M.; Nishida, A.; Nakagawa, M.
Tetrahedron 2004, 60, 3017–3035.
8. Srikrishna, A.; Dattaraya, H. D.; Kumar, P. R. Tetrahedron
Lett. 2004, 45, 2939–2942.
9. Nicolau, K. C.; King, N. P.; He, Y. In Alkene Metathesis in
Organic Synthesis; Furstner, A., Ed.; Springer: New York,
1998; pp 73–104.
10. Hopkins, T.; Wagener, K. B. Macromolecules 2004, 37,
1180–1189.
1
properties were observed: H NMR (CDCl3): d (ppm) 1.28
11. Han, S. Y.; Chang, S. Grubbs, R. H., Ed.; 1st ed.; Handbook of
Metathesis; Wiley-WCH Verlag GmbH: Weinheim, 2003;
Vol. 2, pp 5–127.
(br, 28H), 1.42 (m, 4H, JZ6.7 Hz), 1.88 (q, 4H, J1Z6.7 Hz,
J2Z7.2 Hz, CH2CH2Br), 3.42 (t, 4H, JZ6.9 Hz, CH2Br);
13C NMR (CDCl3): d (ppm) 28.4, 29.7, 29.8, 30.0, 33.1,
34.4; EI/HRMS: [M]C calcd for C20H40Br2: 440.1478,
found: 440.1616.
12. Schrader, T. O.; Snapper, M. L. Grubbs, R. H., Ed.; 1st ed.;
Handbook of Metathesis; Wiley-WCH Verlag GmbH:
Weinheim, 2003; Vol. 2, pp 205–237.
13. Chatterjee, A. K. Grubbs, R. H., Ed.; 1st ed.; Handbook of
Metathesis; Wiley-WCH Verlag GmbH: Weinheim, 2003;
Vol. 2, pp 246–295.
4.5.4. 20-Bromo-eicos-1-ene (9). In a 1 L round bottom
flask compound 8 (50 g, 113 mmol) was dissolved in 2:1

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T. W. Baughman et al. / Tetrahedron 60 (2004) 10943–10948
14. Kilbinger, A. F. M.; Cantrill, S. J.; Waltman, A. W.; Day,
M. W.; Grubbs, R. H. Angew. Chem., Int. Ed. 2003, 42,
3281–3285.
26. Mimoun, H. J. Org. Chem. 1999, 64, 2582–2589.
27. Marvel, C. S.; Garrison, W. E. Jr. J. Am. Chem. Soc. 1959, 18,
4737–4744.
15. Schrader, T. O.; Snapper, M. L. J. Am. Chem. Soc. 2002, 124,
10998–11000.
28. Bartra, M.; Vilarrasa, J. J. Org. Chem. 1991, 56, 5132–5138.
29. Camps, F.; Gasol, V.; Guerrero, A. Synthesis 1987, 511–512.
30. Roux, M. C.; Paugam, R.; Rousseau, G. J. Org. Chem. 2001,
66, 4304–4310.
16. Chaterjee, A. K.; Choi, T. L.; Sanders, D. P.; Grubbs, R. H.
J. Am. Chem. Soc. 2003, 125, 11360–11370.
17. Hoye, T. R.; Van Veidhuizen, J. J.; Vos, T. J.; Zhao, P. Synth.
Commun. 2001, 31, 1367–1371.
31. Patwardhan, A. P.; Thompson, D. H. Langmuir 2000, 16,
10340–10350.
18. Kraus, G. A.; Landgrebe, K. Synthesis 1984, 885.
19. Smith, J. A.; Brzezinska, K. R.; Valenti, D. J.; Wagener, K. W.
Macromolecules 2000, 33, 3781–3794.
32. Tanaka, A.; Oritani, T. Tetrahedron Lett. 1997, 38,
7223–7224.
33. Finkelstein, H. Chemische Berichte 1910, 43, 1528.
34. Roux, M.; Paugam, R.; Rousseau, G. J. Org. Chem. 2001, 66,
4304–4310.
20. Berkessel, A.; Tappe, R.; Riedl, R. J. Am. Chem. Soc. 1998,
120, 8994–9000.
21. Bunnell, R. H.; Shirley, D. A. J. Org. Chem. 1952, 17,
1545–1550.
35. Nguyen, S. T.; Johnson, L. K.; Grubbs, R. H. J. Am. Chem.
Soc. 1992, 114, 3974–3975.
22. Gensler, W. J.; Behrmann, E. M.; Thomas, G. R. J. Am. Chem.
Soc. 1951, 73, 1071–1074.
36. Anh, D.; Blancou, H.; Commeyras, A. J. Fluorine Chem. 1999,
96, 167–174.
23. Brody, F.; Bogert, M. T. J. Am. Chem. Soc. 1943, 65,
1075–1080.
37. Meyer, C.; Marek, I.; Courtemanche, G.; Normant, J.
Tetrahedron 1994, 50, 11665–11692.
24. Berk, S. C.; Buchwald, S. L. J. Org. Chem. 1992, 57,
3751–3753.
38. Lindford, M. R.; Fenter, R.; Eisenberger, P. M.; Chidsey,
C. E. D. J. Am. Chem. Soc. 1995, 117, 3145–3155.
39. Garelli, N.; Vierling, P. J. Org. Chem. 1992, 57, 3046–3051.
25. Reding, M. T.; Buchwald, S. L. J. Org. Chem. 1995, 60,
7884–7890.