(Carboxyalkyl)benzyl propargyl ethers as selective inhibitors of leukocyte-type 12-lipoxygenases

Article abstract of DOI:10.1021/jm9606047

A series of (carboxyalkyl)benzyl propargyl ethers was synthesized and tested as inhibitors of 12-lipoxygenase (12-LO) from porcine leukocyte cytosol. Optimum activity was displayed by 3-[4-[(2- tridecynyloxy)methyl]phenyl]propanoic acid. Altering the length of the alkyl side chain attached to the acetylenic group reduced activity. Changing the substitution pattern in the (carboxyalkyl)benzyl group from para to meta or ortho also reduced activity. Analogs in which the triple bond was replaced by a double bond or an allene displayed reduced activity, whereas fully saturated analogs were inactive. High concentrations (10 μM) of the most potent acetylenic (carboxylalkyl)benzyl ethers did not inhibit human platelet 12-LO, human neutrophil 5-LO, rabbit reticulocyte 15-LO, or soybean 15-LO. Thus, this class of compounds represents the first example of isoform specific LO inhibitors.

Full text of DOI:10.1021/jm9606047

J . Med. Chem. 1996, 39, 4871-4878
4871
Articles
(Ca r boxya lk yl)ben zyl P r op a r gyl Eth er s a s Selective In h ibitor s of
Leu k ocyte-Typ e 12-Lip oxygen a ses
Gilles Gorins,† Lethea Kuhnert,‡ Carl R. J ohnson,† and Lawrence J . Marnett*,‡
Department of Chemistry, Wayne State University, Detroit, Michigan 48202-3489, and Department of Biochemistry,
Vanderbilt University School of Medicine, Nashville, Tennessee 37232
Received August 21, 1996X
A series of (carboxyalkyl)benzyl propargyl ethers was synthesized and tested as inhibitors of
12-lipoxygenase (12-LO) from porcine leukocyte cytosol. Optimum activity was displayed by
3-[4-[(2-tridecynyloxy)methyl]phenyl]propanoic acid. Altering the length of the alkyl side chain
attached to the acetylenic group reduced activity. Changing the substitution pattern in the
(carboxyalkyl)benzyl group from para to meta or ortho also reduced activity. Analogs in which
the triple bond was replaced by a double bond or an allene displayed reduced activity, whereas
fully saturated analogs were inactive. High concentrations (10 µM) of the most potent acetylenic
(carboxylalkyl)benzyl ethers did not inhibit human platelet 12-LO, human neutrophil 5-LO,
rabbit reticulocyte 15-LO, or soybean 15-LO. Thus, this class of compounds represents the
first example of isoform specific LO inhibitors.
Lipoxygenases (LO) are among the oldest and most
extensively studied enzymes of plant and animal me-
tabolism.1,2 The reaction they catalyze is the stereospe-
cific oxygenation of polyunsaturated fatty acids to
hydroperoxy fatty acids (Figure 1).3 Multiple isoforms
exist in both the plant and animal kingdom that differ
in substrate specificity and position of oxygenation.4-8
Mammalian LO’s preferentially oxygenate arachidonic
acid, and different LO’s insert oxygen at the 5, 8, 12,
and 15 positions.7 All LO’s are non-heme iron-contain-
ing proteins (one atom per molecule), and the mam-
malian enzymes are approximately 70 kDa in size.7,8
The iron cycles between the ferric and ferrous oxidation
F igu r e 1. Oxidation of arachidonic acid to (S)-12-hydroper-
oxyeicosatetraenoic acid (HPETE) and conversion to (S)-12-
hydroxyeicosatetraenoic acid (HETE).
states during catalytic turnover, and the ferric form
represents the catalytically active form of the resting
enzyme.9,10
The physiological function of individual mammalian
LO’s is uncertain aside from 5-LO, which catalyzes the
first step of leukotriene biosynthesis.11 Potential func-
tions for the products of other mammalian LO’s include
control of cell proliferation, platelet aggregation, cell
adhesion, tumor metastasis, and atherosclerosis inter
alia.12-15 Our laboratories have been particularly in-
terested in 12-LO’s because of their potential involve-
ment in cell adhesion, endothelial cell retraction, and
tumor metastasis.16-19 Two isoforms of 12-LO exist in
mammals that are the products of different genes and
exhibit differences in tissue distribution, substrate
specificity, and immunochemical reactivity.7,20 The
leukocyte-type enzyme is the product of an 8-kb gene
that is expressed in inflammatory cells, small intestine,
and neural tissue.21,22 The enzyme oxygenates a num-
ber of polyunsaturated fatty acids at nearly equivalent
rates,23 The platelet-type enzyme is the product of a
15-kb gene that is expressed in platelet and epi-
dermis.24-27 This enzyme oxygenates arachidonic acid
at a higher rate than other polyunsaturated fatty
acids.28 There is 58% identity between leukocyte-type
and platelet-type 12-LO.21
Specific 12-LO inhibitors would be useful tools for
differentiating the physiological roles of the two en-
zymes and may serve as lead compounds for drug
development. No specific 12-LO inhibitors have been
described, and in fact, many inhibitors that are specific
for a given LO exhibit some activity against other LO
isoforms.29-31 Therefore, we attempted to design a
series of molecules that would be selective inhibitors of
12-LO’s but not of 5- or 15-LO’s. Since phenols and
hydroxamates react with the iron center of the en-
zymes,29,32 we felt they would be poor choices as
potentially specific inhibitors. The other major class of
molecules that inhibit lipoxygenases is acetylenic fatty
acid analogs.33 These molecules are believed to be
substrates for oxidation by lipoxygenases that lead to
enzyme inactivation during turnover.33-35 Most of the
acetylenic fatty acids that have been described inhibit
a range of lipoxygenases, but Corey and associates have
reported that certain monoacetylenic fatty acids selec-
* Corresponding author: phone, (615) 343-7329; fax, (615) 343-7534;
e-mail, marnett@toxicology.mc.vanderbilt.edu.
† Wayne State University.
‡ Vanderbilt University School of Medicine.
X Abstract published in Advance ACS Abstracts, November 15, 1996.
S0022-2623(96)00604-8 CCC: $12.00 © 1996 American Chemical Society

4872 J ournal of Medicinal Chemistry, 1996, Vol. 39, No. 25
Gorins et al.
Sch em e 2. Method Ba
a
(i) RZNa, THF, 12 h, 25 °C; (ii) I(CH2)nCOOEt, ZnCu, toluene-
dimethylacetamide, 4 h, 60 °C, Pd(Ph3P)4, 24 h; (iii) NaOH, MeOH,
5 h, 25 °C; (iv) LiOH, THF, H2O, 12 h, ∆.
F igu r e 2. Design of arachidonic acid analogs as 12-LO
substrate mimics.
Sch em e 1. Method Aa
Sch em e 3. Method Ca
a
(i) NaCN, DMF, 10 h, 25 °C; (ii) KOH, MeOH, H2O, 24 h, ∆.
Sch em e 4. Method Da
a
(i) TBSCl, imidazole, DMF, 12 h, 25 °C; (ii) Ph3P, imidazole,
I2, CH3CN-Et2O, 1 h, 25 °C; (iii) RONa, THF, 12 h, 25 °C; (iv)
HF, pyridine, CH3CN, 12 h, 25 °C; (v) CH3COO-t-Bu, lithium
diisopropylamide, THF, -78 °C, 1 h; (vi) CF3CO2H, CH2Cl2, 20 h,
25 °C.
a
(1) NBS, benzoyl peroxide, CCl4, 12 h, ∆; (ii) R-ONa, THF, 12
h, 25 °C; (iii) LiOH, THF, H2O, 15 h, 25 °C.
tively inactivate individual lipoxygenases.36-38 Thus,
we designed acetylenic substrate analogs that might
serve as mechanism-based inactivators. Since 12-LO
abstracts the 10(pro-S)-hydrogen atom in the first step
of arachidonic acid oxygenation, we introduced a poten-
tially reactive hydrogen atom appropriately positioned
in a fatty acid analog (Figure 2). The methylene group
containing this hydrogen atom was positioned between
an acetylenic group and a heteroatom to increase the
reactivity of the methylene hydrogen. Finally, we
introduced a phenyl ring at a position approximately
equivalent to the 5,6-double bond of arachidonic acid.
Elaboration of this model quickly identified a series of
molecules that were not only specific for 12-LO but, in
fact, were nearly a 1000-fold selective for leukocyte-type
12-LO as opposed to platelet-type 12-LO.
Sch em e 5a
a
(i) n-BuLi, RI, THF, hexamethylphosphoramide (HMPA), 1 h,
0 °C; (ii) p-TsOH, MeOH, 25 °C; (iii) H2, Pd/CaCO3 (lead poisoned),
EtOAc, 25 °C, 10 h; (iv) LiAlH4, Et2O, reflux, 24 h.
strongly dependent upon the length and position of the
lipophilic chain. The best results were obtained for the
smallest lipophilic chains in a para position relative to
the bromide. Ortho-substituted starting materials were
found resistant to the coupling conditions and were fully
recovered after treatment. The syntheses of arylpro-
panoic or arylbutanoic acid derivatives were completed
by alkaline hydrolyses of the corresponding esters in
methanol.
2. P h en yla cetic Acid s. Various phenylacetic acids
were prepared by treatment of the appropriate benzyl
iodide (see Scheme 1) with NaCN followed by hydrolysis
with KOH/MeOH (Scheme 3, method C).
3. Ben zoic Acid s. The sequence was started with
the NBS bromination of methyl 4-methylbenzoate. The
resulting benzyl bromides were treated with the ap-
propriate alcoholate side chain followed by alkaline
hydrolysis to provide the desired benzoic acid deriva-
tives (Scheme 4, method D).
4. Lip op h ilic Sid e Ch a in s. Various alkynol side
chains were elaborated from the readily available THP
derivative of propargyl alcohol (Scheme 5). The related
cis-allylic alcohols were obtained by partial hydrogena-
tion, whereas the corresponding trans-alcohols were
prepared by treatment of the alkynols with a 2-fold
excess of LiAlH4.41
Resu lts
Ch em istr y. 1. P h en ylp r op a n oic a n d P h en ylbu -
ta n oic Acid s. In the first approach (Scheme 1, method
A), benzenedimethanols were monoprotected by treat-
ment with 1 equiv of TBSCl followed by treatment with
triphenylphosphine/iodine/imidazole39 to produce benzyl
iodides. Ethers were prepared by a standard William-
son synthesis. Subsequent removal of the silyl protec-
tion with hydrofluoric acid in acetonitrile was followed
by iodination of the resulting alcohols. The final
elongations were carried out in THF at -78 °C using
1.1 equiv of the lithium enolate of tert-butyl acetate and
quenching at the same temperature after 1 h. The
resulting esters were hydrolyzed by treatment with
trifluoroacetic acid in dichloromethane or lithium hy-
droxide in methanol and water to afford the propanoic
acid.
In the second approach (Scheme 2, method B), bro-
mobenzyl bromides were converted to ethers or sulfides
utilizing previously prepared long chain alcohols or
thiols. The zinc reagents from ethyl 3-iodopropanoate
and ethyl 4-iodobutanoate were prepared by treatment
with an excess of zinc-copper couple.40 This was
followed by the addition of the aryl bromide and a
catalytic amount of palladium(0). The reaction mixture
was stirred at reflux for a 12-h period. The success of
this palladium(0) coupling procedure was found to be
On the basis of the precedent that various organo-
metallic reagents react with chiral propargylic deriva-
tives to form optically active allenes,42 it was decided
to base our approach on the previously described pro-
pargyl alcohol42 shown in Scheme 6. To prepare the
dextrorotatory allene, the alcohol was treated with

Lipoxygenase Inhibitors
J ournal of Medicinal Chemistry, 1996, Vol. 39, No. 25 4873
Ta ble 1. Meta- and Ortho-Substituted Phenylpropanoic Acids
Sch em e 6a
a
(i) TsCl, Et3N, CH2Cl2, 25 °C, 17 h; (ii) n-C10H21MgBr, CuBr-
dimethyl sulfide, tetrahydrofuran, 0 °C, 0.25 h; (iii) tetrabutylam-
monium fluoride, THF, 25 °C, 2 h; (iv) Ph3P, pyridine, CBr4, THF,
25 °C, 1 h.
p-toluenesulfonyl chloride and triethylamine in dichlo-
romethane to give the tosylate. The latter was subse-
quently subjected to copper-catalyzed Grignard addition
of decylmagnesium bromide to afford the protected
R-allenic alcohol. Further treatment with tetrabutyl-
ammonium fluoride in THF gave the desired dextroro-
tatory allenoic alcohol. (The enantiomeric purity was
determined to be >98% ee by 19F (282 MHz) NMR
spectroscopy of the corresponding Mosher ester.43) The
levorotatory form was prepared by bromination of the
starting propargyl alcohol using carbon tetrabromide-
triphenylphosphine44 in THF containing pyridine. The
resulting bromide was converted to the enantiomeric
allenic alcohol by the same procedure as described
above.
En zym ology. Cytosolic fractions from porcine leu-
kocytes and human platelets were used in a radio-
chemical assay that measured the conversion of [1-14C]-
arachidonic acid to 12-HPETE and its reduction product
12-HETE. An amount of enzyme was used that would
convert approximately 30-50% of 5 µM arachidonate
to products. This concentration is near the Km’s of both
enzymes so that competitive as well as irreversible
inhibitors could be detected. Inhibitor and enzyme were
preincubated for 5 min at 37 °C; then arachidonate was
added. Reactions were terminated after 15 min, and
the products and remaining starting material were
extracted and separated by TLC. The extent of conver-
sion was determined with a TLC radioactivity scanner.
Compounds were initially evaluated at 1 and 10 µM
concentrations, and if inhibition was observed, an IC50
was determined. All incubations were carried out in
triplicate, and IC50’s were repeated to verify their
accuracy.
Ta ble 2. Para-Substituted Phenylbutanoic, Phenylpropanoic,
Phenylacetic, and Benzoic Acids 3
compound
n
R
method
IC50 (µM)
3a
3b
3c
3d
3e
3f
3g
3h
3i
3
2
2
2
2
2
2
1
0
0
0
n-C10H21
n-C6H13
n-C8H17
n-C10H21
n-C12H25
n-C14H29
Ph(CH2)4
n-C10H21
n-C10H21
n-C7H15
n-C14H29
B
A
A
B
A
A
A
C
D
D
D
>10
2.0
0.10
0.035
0.32
>10
5.0
0.05
0.06
6.0
3j
3k
>10
decyl, e.g., 3e,f, reduced inhibitor efficacy. Thus, in
most subsequent syntheses, the length of the ω alkyl
chain was fixed at 10 carbons. Substitution of phenyl
in the alkyl chain, see 3g, produced a relatively poor
inhibitor. Shortening the carboxyalkyl chain from aryl-
propionyl to benzoyl had relatively little effect on
inhibitory potency (3d ,h ,i), whereas lenghthening it to
arylbutyryl significantly decreased potency (3a ).
The importance of the triple bond was investigated
with the series of compounds listed in Table 3. Substi-
tution of a double bond for the triple bond, cf. 4 and 5
vs 3d , reduced activity approximately 10-100-fold. The
trans-isomer 4 was approximately 6 times more active
than the cis-isomer 5. Complete reduction to the
hydrocarbon as in 8 eliminated activity up to 10 µM.
Enantiomeric allenes 6 and 7 were synthesized that
demonstrated approximately 10-fold less activity than
3d . However, these compounds each contain one extra
carbon in the ω side chain of the molecule relative to
3d , and as discussed above, inhibitory potency was very
sensitive to the length of this side chain. Incorporation
of the extra carbon may have contributed to the decrease
in activity. The data in Table 3 indicate that for
The initial compound tested was 1a ; the features that
went into its design are outlined above. Compound 1a
exhibited very weak activity, but substitution of O for
sulfur as in 1b improved the inhibitory potency some-
what (Table 1). The ability to inhibit 12-LO was quite
dependent on the orientation of the propanoic acid
residue on the phenyl ring, as indicated by the com-
pounds 1c, 2, and 3d (Table 2). Para substitution led
to the most potent inhibitors and ortho substitution the
least potent.
A dramatic dependence on the length of the alkyl side
chain was observed (Table 2). A 60-fold increase in
potency accompanied the lengthening of the chain from
hexyl to decyl (3b vs 3d ). Increasing the length beyond

4874 J ournal of Medicinal Chemistry, 1996, Vol. 39, No. 25
Gorins et al.
Ta ble 3. Effect of Various Unsaturations in the Lipophilic
Chain
striking is the lack of inhibitory activity against the
platelet-type 12-LO. Substrate specificity studies of the
two LO isoenzymes indicate that the leukocyte-type
enzyme will act on a much broader range of polyun-
saturated fatty acid than will the platelet-type en-
zyme.5,7,23 This suggests that the leukocyte-type en-
zyme has a more accommodating substrate access
channel than the platelet-type enzyme. Thus, the
leukocyte-type enzyme may bind substrate analogs more
easily than the platelet-type enzyme does.
Acetylenic inhibitors of LO and cyclooxygenase are
believed to act as reactive substrate analogs that
generate oxidants during turnover leading to loss of
enzyme activity.33-35 The (carboxyalkyl)benzyl ethers
prepared in this study were designed based on this
premise, and the structure-activity for inhibition that
we have determined is consistent with the hypothesis
that they are mechanism-based inhibitors.
Deuteration of the methylene group between the ether
oxygen and the triple bond in the parent compound 3d
did not affect inhibitory potency, which one might have
expected if oxidation of the methylene group was a key
step in LO inhibition (G. Gorin and L. Kuhnert, unpub-
lished results). For example, 15-LO from soybeans
maximal activity a double or triple bond is required in
a side chain.
All of the compounds described above were also tested
against the human platelet cytosol 12-LO. No inhibition
of activity was detected with any of the compounds at
concentrations as high as 10 µM. A limited number of
the more potent inhibitors of leukocyte-type 12-LO were
also tested against human neutrophil 5-LO and rabbit
reticulocyte 15-LO but were inactive at 10 µM. Thus,
the (carboxyalkyl)benzyl propargyl ethers described
herein appeared to be highly selective for leukocyte-type
12-LO. For comparison, 5,8,11,14-eicosatetraynoic acid
(ETYA) was tested against our porcine leukocyte and
human platelet 12-LO’s preparations. ETYA inhibited
leukocyte-type 12-LO with an IC50 of 0.05 µM and
platelet-type 12-LO with an IC50 of 0.5 µM. These
findings underscore the potency and selectivity of the
acetylenic (carboxyalkyl)benzyl ethers against porcine
leukocyte 12-LO.
exhibits an extraordinarily high isotope effect (kH/kD
∼
80) for hydrogen removal from linoleic acid.48 However,
the magnitude of the isotope effect observed depends
on temperature, viscosity, etc.48 Furthermore, detailed
kinetic studies similar to those reported for the plant
LO’s have not been reported for any of the mammalian
LO’s so the magnitude of kinetic isotope effects for
hydrogen removal from substrates or potential inhibi-
tors is not known. Thus, it is hard to predict whether
deuteration should alter the rate of inhibitor oxidation
and LO inactivation.
The present work defines the structural requirements
for inhibition of leukocyte-type 12-LO by a novel series
of acetylenic arachidonic acid analogs that are the first
to display specificity for a single LO isoform. These
compounds or derivatives elaborated from them should
be useful in exploring the role of leukocyte 12-LO in
physiological and pathophysiological processes.
Discu ssion
Acetylenic analogs of polyunsaturated fatty acids have
long been recognized as inhibitors of fatty acid oxyge-
nases such as lipoxygenase and cyclooxygenase.33,35,45
In most cases, these acetylenic compounds inhibit one
or more LO’s and cyclooxygenase, but certain acetylenic
arachidonic acid analogs have been described as selec-
tive inhibitors of different LO isoenzymes.36-38,46,47 The
series of substituted (carboxyalkyl)benzyl ethers de-
scribed in the present study represent a series of potent
and selective inhibitors of leukocyte-type 12-LO. The
key structural features required for potent inhibition
include a methylene group between the benzyl ether and
a site of unsaturation (preferably a triple bond), a decyl
side chain attached to the acetylenic group, and para
substitution in the substituted benzyl ether.
A high degree of selectivity within this series of
compounds was observed for inhibition of leukocyte-type
12-LO. No inhibition of human platelet-type 12-LO,
human neutrophil 5-LO, rabbit reticulocyte 15-LO,
soybean 15-LO, or sheep seminal vesicle cyclooxygenase
was observed at concentrations as high as 10 µM. This
series of compounds appears to be the most selective
group of LO inhibitors described to date. Particularly
Exp er im en ta l Section
Ma ter ia ls. En zym ology: P r ep a r a tion of P or cin e Leu -
k ocyte a n d Hu m a n P la telet Cytosol. The assay mixture
contained porcine leukocyte or human platelet cytosol (75 µg/
mL) in 100 mM HEPES, 2 mM CaCl2, and 1 mM MgCl2, pH
8.0, in a total volume of 100 µL. Inhibitors were added in 3
µL of DMSO and preincubated for 5 min at 37 °C. [1-14C]-
Arachidonic acid was added to a final concentration of 5 µM,
and the reactions were allowed to proceed for 15 min. Dilute
HCl was added to acidify, and unlabeled 12-HETE (5 µM) and
arachidonic acid (100 µM) were added as carrier. The samples
were extracted with water-saturated ethyl acetate, and an
aliquot was spotted onto silica gel TLC plates. The plates were
developed with dichloromethane/ethyl acetate/acetic acid, 70/
30/1. The Rf’s of 12-HETE and arachidonic acid in this solvent
system were 0.30 and 0.45, respectively. The percentage
conversion to 12-HETE was calculated from the percentage
of the total 14C on the TLC plate that coleuted with a standard
of 12-HETE.
Syn th esis. P h en ylpr opan oic Acid Der ivatives. Meth od
A: [4-[[(ter t-Bu tyldim eth ylsilyl)oxy]m eth yl]ph en yl]m eth -
a n ol. A flask was charged with 3.00 g of a 60% dispersion of
NaH in oil. The dispersion was washed with three 10-mL
portions of THF. The NaH was suspended in 70 mL of THF
and cooled to 0 °C, followed by the slow addition of a solution
of 1,4-benzenedimethanol (Aldrich) (8.50 g, 62 mmol) in THF

Lipoxygenase Inhibitors
J ournal of Medicinal Chemistry, 1996, Vol. 39, No. 25 4875
(10 mL) to the mixture. After 25 min at 0 °C, an additional
40-mL portion of THF was added to the mixture, and the cold
bath was removed. The reaction mixture was stirred at 25
°C for 30 min and then recooled to 0 °C. At this time, tert-
butyldimethylsilyl chloride (10.19 g, 68.20 mmol, 1.1 equiv)
was added to the mixture. The solution was allowed to warm
to 25 °C over a 1-h period and was stirred at this temperature
for an additional 12 h. The mixture was poured into 50 mL
of water and extracted with three 50-mL portions of ether. The
combined ether extracts were dried over MgSO4, filtered, and
concentrated in vacuo to yield a yellow oil. Purification by
flash silica gel chromatography (85:15 petroleum ether/EtOAc)
yielded 9.6 g (50%) of the monoprotected title compound as a
clear oil: Rf 0.62 (8:2 petroleum ether/EtOAc); IR (neat) 3550-
3100 (b, OH), 3000, 2800, 1600, 1493, 1256, 1192, 1131, 1087
cm-1; 1H NMR (CDCl3) δ 7.31 (s, 4 H), 4.75 (s, 2 H), 4.60 (d, J
) 5.4 Hz, 2 H), 2.60 (s, 1 H), 0.97 (s, 9 H), 0.13 (s, 6 H); 13C
NMR (CDCl3) δ 140.89, 139.77, 127.12, 126.39, 65.07, 64.95,
26.11, 18.57, -5.08. Anal. (C14H24O2Si) C, H.
3393, 3013, 2921, 2851 cm-1; 1H NMR (CDCl3) δ 7.30 (s, 4 H),
5.60 (m, 2 H), 4.63 (s, 2 H), 4.49 (s, 2 H), 4.07 (d, J ) 5.1 Hz,
2 H), 2.39 (s, 2 H), 2.04 (q, J ) 6.6 Hz, 2 H), 1.27 (m, 16 H),
0.89 (t, J ) 6.6 Hz, 2 H); 13C NMR (CDCl3) δ 140.49, 137.82,
134.24, 128.10, 127.12, 125.94, 71.88, 65.85, 65.03, 32.03,
29.76, 29.66, 29.48, 29.37, 27.73, 22.82, 14.24. Anal. (C21H34O2)
C, H.
cis-1-(Iod om e t h yl)-4-[(2-t r id e ce n yloxy)m e t h yl]b e n -
zen e. A flask was charged with Ph3P (314 mg, 1.2 mmol, 1.5
equiv), imidazole (109 mg, 1.6 mmol, 2 equiv), and 10 mL of a
3/1 mixture of Et2O/CH3CN. The resulting mixture was stirred
until dissolution was complete. At this time, I2 (305 mg, 1.2
mmol, 1.5 equiv) was added, and vigorous stirring was
continued until a yellow suspension formed, and a solution of
the above alcohol (250 mg, 0.8 mmol) in 1 mL of the same
solvent was then added. After 1 h, the mixture was concen-
trated in vacuo, and the resulting yellow oil was taken up into
50 mL of hexane and 30 mL of a saturated solution of sodium
bisulfite; this was extracted with two 30-mL portions of
hexane. The combined organic extracts were dried over
MgSO4, filtered, and concentrated in vacuo to yield a yellow
oil. Purification by flash silica gel chromatography (95:5
petroleum ether/EtOAc) afforded 350 mg (93%) of the title iodo
derivative as a clear colorless oil: Rf 0.75 (9:1 petroleum ether/
EtOAc); 1H NMR (CDCl3) δ 7.33 (d, J ) 8.1 Hz, 2 H), 7.18 (d,
J ) 8.1 Hz, 2 H), 5.62 (m, 2 H), 4.45 (s, 2 H), 4.40 (s, 2 H),
4.05 (d, J ) 5.1 Hz, 2 H), 2.05 (m, 2 H), 1.37 (m, 16 H), 0.91 (t,
1-[[(ter t-Bu tyld im eth ylsilyl)oxy]m eth yl]-4-(iod om eth -
yl)ben zen e. A flask was charged with Ph3P (3.93 g, 15 mmol,
1.5 equiv), imidazole (1.24 g, 20 mmol, 2 equiv), and a 3/1
mixture of Et2O/CH3CN (100 mL). The mixture was stirred
until dissolution was complete. At this time, I2 (3.81 g, 15
mmol, 1.5 equiv) was added, and vigorous stirring was
continued until a yellow suspension formed. A solution of the
above benzyl alcohol (3.58 g, 10 mmol) in 10 mL of the same
solvent was then added. After 1 h, the mixture was concen-
trated in vacuo, the resulting crude material was taken up
into 100 mL of hexane, and the solution was washed with 100
mL of a saturated solution of sodium bisulfite. The aqueous
solutions were back-extracted with two 100-mL portions of
hexane. The combined organic extracts were dried over
MgSO4, filtered, and concentrated in vacuo to yield a yellow
oil. Purification by flash silica gel chromatography (95:5
petroleum ether/EtOAc) afforded 4.40 g (93%) of the iodo
derivative as a clear colorless oil: Rf 0.85 (9:1 petroleum ether/
EtOAc); IR (neat) 2957, 2929, 2858, 1470, 1372, 1252, 1047,
J ) 6.6 Hz, 3 H);
13C NMR (CDCl3) δ 138.50, 138.69, 134.26,
128.91, 128.28, 125.97, 71.74, 66.02, 32.06, 29.78, 29.70, 29.51,
29.38, 27.78, 22.86, 14.30, 5.66.
ter t-Bu tyl cis-3-[4-[(2-Tr id ecen yloxy)m eth yl]p h en yl]-
p r op a n oa te. A solution of tert-butyl acetate (0.2 mL, 1.5
mmol, 2 equiv) in dry THF (1 mL) was added to a solution of
LDA. (The latter was prepared by adding n-BuLi (0.68 mL,
2.5 M in hexane, 1.72 mmol) to a solution of diisopropylamine
(0.10 mL, 1.89 mmol) in THF (4 mL) at -78 °C and stirring
for 30 min.) The resulting mixture was stirred for 30 min at
-78 °C, and the above iodide (350 mg, 0.75 mmol) in THF (1
mL) was added. After 1 h, the reaction mixture was allowed
to warm to 0 °C and immediately poured into water (20 mL)
and ether (30 mL). The organic layer was separated and
washed with three 15-mL portions of water. The ether extract
was dried (MgSO4), filtered, and concentrated by rotary
evaporation. Flash chromatography eluted by 95:5 petroleum
ether/EtOAc furnished the title ester (250 mg, 78%) as a
colorless oil: Rf 0.68 (9:1 petroleum ether/EtOAc); 1H NMR
(CDCl3) δ 7.27 (d, J ) 8.1 Hz, 2 H), 7.17 (d, J ) 8.1 Hz, 2 H),
5.59 (m, 2 H), 4.47 (s, 2 H), 4.06 (d, J ) 4.5 Hz, 2 H), 2.90 (t,
J ) 7.8 Hz, 2 H), 2.53 (t, J ) 7.8 Hz, 2 H), 2.04 (m, 2 H), 1.42
(s, 9 H), 1.27 (m, 16 H), 0.89 (t, J ) 6.9 Hz, 3 H); 13C NMR
(CDCl3) δ 172.32, 140.26, 136.38, 134.02, 128.44, 128.07,
126.13, 80.38, 71.96, 65.78, 37.18, 32.03, 30.95, 29.74, 29.67,
29.63, 29.47, 29.36, 28.18, 27.73, 22.79, 14.24. Anal. (C27H44O3)
C, H.
1
836, 780, 667, 562, 527 cm-1; H NMR (CDCl3) δ 7.35 (d, J )
8.1 Hz, 2 H), 7.26 (d, J ) 8.1 Hz, 2 H), 4.71 (s, 2 H), 4.47 (s, 2
H), 0.96 (s, 9 H), 0.11 (s, 6 H); 13C NMR (CDCl3) δ 141.28,
137.78, 128.63, 126.39, 64.60, 25.95, 5.89, -5.25.
cis-1-[[(ter t-Bu t yld im et h ylsilyl)oxy]m et h yl]-4-[(2-t r i-
d ecen yloxy)m eth yl]ben zen e. A flask was charged with 60
mg of a 60% dispersion of NaH in oil. The dispersion was
washed with three 2-mL portions of THF. The NaH was
suspended in 5 mL of THF and cooled to 0 °C. A solution of
cis-2-tridecen-1-ol (206 mg, 1.1 mmol, 1.1 equiv) in THF (1 mL)
was slowly added to the mixture. After 25 min the cold bath
was removed, and stirring was continued for an additional 10
min. At this time a solution of the above benzyl iodide (361
mg, 1 mmol) in THF (1 mL) was added, and stirring was
continued for 12 h. The mixture was poured into water (20
mL) and ether (25 mL). The organic layer was separated and
washed with three 10-mL portions of water. The ether extract
was dried (MgSO4), filtered, and concentrated by rotary
evaporation to yield a yellow oil. Purification by flash silica
gel chromatography (95:5 petroleum ether/EtOAc) afforded 341
mg (85%) of the title compound as a clear colorless oil: Rf 0.80
(9:1 petroleum ether/EtOAc); IR (neat) 3013, 2929, 2851, 1682,
1654, 1463, 1252, 1090, 836, 780 cm-1; 1H NMR (CDCl3) δ 7.20
(s, 4 H), 5.61 (m, 2 H), 4.76 (s, 2 H), 4.52 (s, 2 H), 4.08 (d, J )
4.8 Hz, 2 H), 2.05 (m, 2 H), 1.29 (m, 16 H), 0.97 (s, 9 H), 0.91
(t, J ) 6.9 Hz, 3 H), 0.12 (s, 6 H); 13C NMR (CDCl3) δ 140.76,
137.04, 127.71, 126.04, 125.98, 71.86, 65.58, 64.80, 31.92,
29.62, 29.56, 29.52, 29.24, 29.36, 27.61, 25.94, 22.69, 18.57,
14.12, -5.25. Anal. (C27H48O2Si) C, H.
cis-3-[4-[(2-Tr id ecen yloxy)m et h yl]p h en yl]p r op a n oic
Acid (5). A solution of the above ester (250 mg, 0.6 mmol) in
a 1:5 mixture of trifluoroacetic acid and CH2
Cl2 (10 mL) was
stirred at 25 °C for 12 h and evaporated to dryness in vacuo
at room temperature. Purification by flash silica gel chroma-
tography (25:1 CH2
Cl2/MeOH) afforded 205 mg (95%) of the
title phenylpropanoic acid derivative as a white solid: mp 35-
36 °C; Rf 0.35 (20:1 CH2Cl2/MeOH); IR (neat) 3400, 2951, 2921,
2851, 1703, 1442, 1111, 942, 815 cm-1 1H NMR (CDCl3) δ
;
10.50 (s, 1 H), 7.30 (d, J ) 7.8 Hz, 2 H), 7.20 (d, J ) 7.8 Hz,
2 H), 5.61 (m, 2 H), 4.50 (s, 2 H), 4.09 (d, J ) 4.8 Hz, 2 H),
2.97 (t, J ) 7.8 Hz, 2 H), 2.68 (t, J ) 7.8 Hz, 2 H), 2.05 (m, 2
H), 1.28 (m, 16 H), 0.90 (t, J ) 6.6 Hz, 3 H); 13C NMR (CDCl3)
δ 179.06, 139.71, 136.59, 134.22, 128.42, 128.28, 125.98, 71.89,
65.83, 35.75, 32.04, 30.4329.75, 29.67, 29.47, 29.37,27.74,22.81,
14.24; HRMS calcd for C23H36O3 (M•+) 360.2664, found 360.2658.
Anal. (C23H36O3) C, H.
cis-[4-[(2-Tr id ecen yloxy)m eth yl]p h en yl]m eth a n ol. To
a solution of the above silyl ether (341 mg, 0.84 mmol) in CH3-
CN (10 mL) was added 50% aqueous HF (1 mL); the mixture
was stirred at room temperature for 15 min. The reaction
mixture was poured into saturated aqueous NaHCO3 (50 mL)
and ether (75 mL). The organic layer was separated, washed
with two 50-mL portions of water, dried (MgSO4), and con-
centrated to yield the title compound (290 mg, 98%) as a
colorless oil: Rf 0.24 (9:1 petroleum ether/EtOAc); IR (neat)
P h en ylp r op a n oic a n d P h en ylbu ta n oic Acid Der iva -
tives. Meth od B: 1-Br om o-3-[(3-n on yn yloxy)m eth yl]-
ben zen e. A flask was charged with 50 mg of a 60% dispersion
of NaH in oil. The dispersion was washed with three 2-mL
portions of THF. The NaH was suspended in 5 mL of THF

4876 J ournal of Medicinal Chemistry, 1996, Vol. 39, No. 25
Gorins et al.
and cooled to 0 °C. A solution of 3-nonyn-1-ol (152 mg, 1.1
mmol, 1.1 equiv) in THF (1 mL) was slowly added. After 25
min the cold bath was removed, and stirring was continued
for an additional 10 min. At this time a solution of 3-bro-
mobenzyl bromide (250 mg, 1 mmol) in THF (1 mL) was added
and stirring continued for 12 h. The mixture was poured into
water (20 mL) and ether (25 mL). The organic layer was
separated and washed with three 10-mL portions of water. The
ether extract was dried (MgSO4), filtered, and concentrated
by rotary evaporation to yield a yellow oil. Purification by
flash silica gel chromatography (95:5 petroleum ether/EtOAc)
afforded 262 mg (85%) of the title product as a clear colorless
28.59, 22 65, 18.74, 14.10; HRMS calcd for C20H29BrO (M•+
364.1402, found 364.1408.
)
Eth yl 3-[4-[(2-tr idecyn yloxy)m eth yl]ph en yl]pr opan oate:
1
colorless oil; IR (neat) 1715 cm-1; H NMR (CDCl3) δ 7.28 (d,
J ) 7.8 Hz, 2 H), 7.19 (d, J ) 7.8 Hz, 2 H), 4.55 (s, 2 H), 4.14
(m, 4 H), 2.95 (t, J ) 8.1 Hz, 2 H), 2.60 (t, J ) 8.1 Hz, 2 H),
2.23 (m, 2 H), 1.27 (m, 19 H), 0.88 (t, J ) 6.6 Hz, 2 H); 13C
NMR (CDCl3) δ 173.03, 140.14, 135.54, 128.32, 87.15, 75.90,
71.04, 60.39, 57.63, 35.88, 31.85, 30.64, 29.52, 29.30, 29.11,
28.86, 28.60, 22.65, 18.76, 14.16, 14.09; HRMS calcd for
C25H38O3 (M•+) 386.2821, found 386.2826.
3-[4-[(2-Tr id ecyn yloxy)m eth yl]p h en yl]p r op a n oic a cid
(3d ): white crystals; mp 49 °C; IR (neat) 3250, 2957, 2921,
1
oil: Rf 0.88 (9:1 petroleum ether/EtOAc); H NMR (CDCl3) δ
2851, 2302, 2238, 1696, 1463, 1259, 1069, 1020, 942, 801 cm-1
;
7.40 (m, 4 H), 4.55 (s, 2 H), 3.56 (t, J ) 6.9 Hz, 2 H), 2.48 (tt,
J 1 ) 6.9 Hz, J 2 ) 2.4 Hz, 2 H), 2.15 (tt, J 1 ) 7.2 Hz, J 2 ) 2.4
Hz, 2 H), 1.40 (m, 6 H), 0.89 (t, J ) 7.2 Hz, 3 H); 13C NMR
(CDCl3) δ 140.82, 130.78, 130.65, 130.09, 126.12, 122.68, 81.81,
72.74, 69.29, 31.20, 28.80, 22.35, 20.29, 18.86, 14.12.
1H NMR (CDCl3) δ 10.50 (s, 1 H), 7.30 (d, J ) 8.1 Hz, 2 H),
7.19 (d, J ) 8.1 Hz, 2 H), 4.56 (s, 2 H), 4.15 (t, J ) 1.8 Hz, 2
H), 2.96 (t, J ) 7.8 Hz, 2 H), 2.68 (t, J ) 7.8 Hz, 2 H), 2.23 (tt,
J 1 ) 7.2 Hz, J 2 ) 2.1 Hz, 2 H), 1.27 (m, 16 H), 0.88 (t, J ) 6.9
Hz, 2 H); 13C NMR (CDCl3) δ 178.86, 139.88, 135.88, 128.59,
128.45, 87.52, 75.90, 71.16, 57.81, 35.66, 32.02, 30.41, 29.89,
29.44, 29.27, 29.02, 28.77, 22.80, 18.91, 14.24; HRMS calcd
for C23H34O3 (M•+) 358.2507, found 358.2511. Anal. (C23H34O3)
C, H.
Eth yl 3-[3-[(3-Non yn yloxy)m eth yl]p h en yl]p r op a n oa te.
A flask was charged with Zn-Cu couple (200 mg, 3 mmol),
and a solution of ethyl 3-iodopropanoate (510 mg, 2 mmol) in
dry toluene (4 mL) and dry N,N-dimethylacetamide (2 mL)
was added. The mixture was vigorously stirred for 1 h at room
temperature and then heated at gentle reflux for 4.5 h. After
the mixture was cooled to 60 °C, a solution of tetrakis-
(triphenylphosphine)palladium(0) (30 mg, 0.026 mmol) in
toluene (2 mL) was added over 1 min, and stirring was
continued for 5 min at the same temperature. A solution of
the above aryl bromide (309 mg, 1 mmol) in dry toluene (2
mL) was added, and the mixture was refluxed for 12 h. The
reaction mixture was allowed to cool to 25 °C and filtered
through a Celite pad. The filter cake was washed with ether
(50 mL). The filtrate was successively washed with a solution
of 1 N ammonium chloride (10 mL), a solution of saturated
sodium hydrogen carbonate (10 mL), and a solution of satu-
rated sodium chloride (10 mL). The aqueous phases were
back-extracted with ether (30 mL); the combined organic
extracts were dried (MgSO4), filtered, and concentrated by
rotary evaporation to yield a yellow oil. Purification by flash
silica gel chromatography (97:3 petroleum ether/EtOAc) af-
forded the title ester (165 mg, 51%) as a colorless oil: Rf 0.44
(95:5 petroleum ether/EtOAc); IR (neat) 2929, 2858, 1738,
1449, 1374, 1160, 1111, 787, 703 cm-1; 1H NMR (CDCl3) δ 7.19
(m, 4 H), 4.51 (s, 2 H), 4.12 (q, J ) 7.2 Hz, 2 H), 3.55 (t, J )
7.2 Hz, 2 H), 2.94 (t, J ) 8.1 Hz, 2 H), 2.61 (t, J ) 8.1 Hz, 2
H), 2.46 (tt, J 1 ) 6.9 Hz, J 2 ) 2.1 Hz, 2 H), 2.13 (tt, J 1 ) 7.2
Hz, J 2 ) 2.4 Hz, 2 H), 1.40 (m, 6 H), 1.22 (t, J ) 7.2 Hz, 3 H),
0.88 (t, J ) 6.9 Hz, 3 H); 13C NMR (CDCl3) δ 173 01, 140.87,
138.58, 128.68, 127.75, 81.64, 76.67, 72.99, 69.15, 60.53, 36.02,
31.01, 31.18, 28.81, 22.34, 20.28, 18.85, 14.32, 14.12. Anal.
(C20H30O3) C, H.
3-[3-[(3-Non yn yloxy)m et h yl]p h en yl]p r op a n oic Acid
(1e). A solution of the above ester (150 mg, 0.45 mmol) in a
mixture of MeOH (4 mL) and 1 N NaOH (1 mL) was stirred
at room temperature for 3 h. The reaction mixture was
concentrated in vacuo, H2O (20 mL) was added, and the pH
was adjusted to 4 with 10% AcOH. Ether (30 mL) was added.
The organic layer was separated and washed with water (20
mL). The ether extract was dried (MgSO4) and concentrated
by rotary evaporation. Purification by flash silica gel chro-
matography (20:1 CH2Cl2/MeOH) afforded 1e (129 mg, 95%)
as a colorless oil: Rf 0.31 (20:1 CH2Cl2/MeOH); IR (neat) 3500,
2929, 2858, 2245, 1710, 1104, 731, 703 cm-1; 1H NMR (CDCl3)
δ 10.5 (s, 1 H), 7.21 (m, 4 H), 4.55 (s, 2 H), 3.57 (t, J ) 6.9 Hz,
2 H), 2.97 (t, J ) 8.1 Hz, 2 H), 2.69 (t, J ) 8.1 Hz, 2 H), 2.49
The corresponding dideutero compound (-Cy¨CCD2-O-) was
prepared by reduction of methyl 2-tridecynoate with LiAlD4
in diethyl ether at room temperature followed by coupling of
the corresponding propargyl alcohol with 4-bromobenzyl bro-
mide and proceeding as in the preparation of 3d . The 1H NMR
spectrum of 3d -d2 matched that above except for the absence
of the triplet at 4.15.
Ar yla cetic Acid Der iva tives. Meth od C: [4-[(2-Tr id ec-
yn yloxy)m eth yl]p h en yl]a ceton itr ile. A solution of 1-(io-
domethyl)-4-[(2-tridecynyloxy)methyl]benzene (100 mg, 0.23
mmol) and NaCN (20 mg, 1.5 equiv) in DMF (2 mL) was stirred
for 5 h at 25 °C. The resulting mixture was poured in water
(20 mL) and ether (25 mL). The organic layer was separated
and washed with two 10-mL portions of water. The ether
extract was dried (MgSO4), filtered, and concentrated by rotary
evaporation to yield a yellow oil. Purification by flash silica
gel chromatography (95:5 petroleum ether/EtOAc) afforded the
title nitrile (66 mg, 95%) as a clear oil: Rf 0.3 (9:1 petroleum
1
ether/EtOAc); H NMR (CDCl3) δ 7.38 (d, J ) 8.1 Hz, 2 H),
7.31 (d, J ) 8.1 Hz, 2 H), 4.59 (s, 2 H), 4.17 (t, J ) 2.1 Hz, 2
H), 3.74 (s, 2 H), 2.24 (tt, J 1 ) 6.9 Hz, J 2 ) 1.8 Hz, 2 H), 1.35
(m, 16 H), 0.88 (t, J ) 6.9 Hz, 3 H); 13C NMR (CDCl3) δ 137.99,
129.44, 128.86, 128.10, 117.95, 87.74, 75.73, 70.80, 58.04,
32.01, 29.67, 29.44, 29.25, 29.01, 28.74, 23.48, 22.80, 18.89,
14.23.
4-[(2-Tr id ecyn yloxy)m eth yl]p h en yla cetic Acid (3h ).
The above nitrile (66 mg) was dissolved in MeOH (1 mL) and
water (1 mL). LiOH (50 mg) was added, and the resulting
mixture was refluxed for 35 h. The mixture was allowed to
cool to 25 °C, acidified, extracted with ether (25 mL), dried
(MgSO4), filtered, and concentrated by rotary evaporation to
yield a yellow oil. Purification by flash silica gel chromatog-
raphy (96:4 CH2Cl2/MeOH) afforded 3h (50 mg, 90%) as a clear
oil: Rf 0.4 (95:5 CH2Cl2/MeOH); IR (neat) 3400, 2921, 2851,
1696, 1463, 1407, 1076, 991, 773 cm-1; 1H NMR (CDCl3) δ 9.5
(s, 1 H), 7.27 (m, 4 H), 4.57 (s, 2 H), 4.14 (s, 2 H), 3.62 (s, 2 H),
2.22 (m, 2 H), 1.34 (m, 16 H), 0.87 (s, 3H); 13C NMR (CDCl3)
δ 178.20, 136.78, 132.74, 129.38, 128.32, 70.83, 57.67, 40.74,
31.86, 29.52, 29.29, 29.10, 28.86, 28.60, 22.33, 18.75, 14.09.
Anal. (C22H32O3) C, H.
Ben zoic Acid Der iva tives. Meth od D: Meth yl 4-(Br o-
m om eth yl)ben zoa te. A solution of methyl 4-methylbenzoate
(1.50 g, 10 mmol), N-bromosuccinimide (1.78 g, 10 mmol, 1.0
equiv), and a catalytic amount of benzoyl peroxide (30 mg, 0.12
mmol) in CCl4 (50 mL) was stirred at gentle reflux for 15 h.
The resulting mixture was allowed to cool to 25 °C and filtered.
The solvent was removed by rotary evaporation. The resulting
slurry was chromatographed on silica gel (98:2 petroleum
ether/ethyl acetate) to afford a mixture of brominated com-
pounds. Recrystallization of the crude mixture from petroleum
ether afforded the title compound as white crystals (1.8 g,
(tt, J 1 ) 7.2 Hz, J 2 ) 2.4 Hz, 2 H), 2.15 (tt, J 1 ) 6.9 Hz, J 2
)
2.1 Hz, 2 H), 1.40 (m, 6 H), 0.90 (t, J ) 6.9 Hz, 3H); 13C NMR
(CDCl3) δ 179.20, 140.47, 138.62, 128.78, 127.73, 125.93, 81.69,
76.67, 72.95, 69.15, 35.70, 31.21, 30.63, 28.83, 22.36, 20.27,
18.86, 14.12. Anal. (C19H26O3) C, H.
1-Br om o-4-[(2-tr id ecyn yloxy)m eth yl]ben zen e: colorless
1
oil; H NMR (CDCl3) δ 7.46 (d, J ) 8.4 Hz, 2 H), 7.23 (d, J )
8.4 Hz, 2 H), 4.53 (s, 2 H), 4.15 (t, J ) 2.1 Hz, 2 H), 2.23 (tt,
J 1 ) 7.2 Hz, J 2 ) 2.1 Hz, 2 H), 1.40 (m, 16 H), 0.88 (t, J ) 6.9
Hz, 2 H); 13C NMR (CDCl3) δ 136.74, 131.44, 129.59, 121.57,
87.60, 75.50, 70.45, 57.84, 31.86, 29.53, 29.30, 29.10, 28.86,
1
80%): mp 53-54 °C; H NMR (CDCl3) δ 8.00 (d, J ) 8.1 Hz,
2 H), 7.44 (d, J ) 8.1 Hz, 2 H), 4.48 (s, 2 H), 3.90 (s, 3 H); 13
C

Lipoxygenase Inhibitors
J ournal of Medicinal Chemistry, 1996, Vol. 39, No. 25 4877
(12) Furstenberger, G. Role of eicosanoids in mammalian skin
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NMR (CDCl3) δ 166.48, 142.57, 130.03, 129.00, 52.20, 32.22.
Anal. (C9H9BrO2) C, H.
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lial cells. Annu. Rev. Physiol. 1992, 54, 303-329.
Meth yl 4-[(2-Decyn yloxy)m eth yl]ben zoa te. A flask was
charged with 50 mg of a 60% dispersion of NaH in oil. The
dispersion was washed with three 2-mL portions of THF. The
NaH was suspended in 5 mL of THF and cooled to 0 °C. A
solution of 2-decyn-1-ol (169 mg, 1.1 mmol, 1.1 equiv) in THF
(1 mL) was slowly added. After 25 min the cold bath was
removed, and stirring was continued for an additional 10 min.
At this time a solution of methyl 4-(bromomethyl)benzoate (229
mg, 1 mmol) in THF (1 mL) was added and stirring continued
for 12 h. The mixture was poured into water (20 mL) and
ether (25 mL). The organic layer was separated and washed
with three 10-mL portions of water. The ether extract was
dried (MgSO4), filtered, and concentrated by rotary evaporation
to yield a yellow oil. Purification by flash silica gel chroma-
tography (95:5 petroleum ether/EtOAc) afforded 181 mg (60%)
of the title ester as a clear colorless oil: Rf 0.76 (9:1 petroleum
(14) Piomelli, D.; Greengard, P. Lipoxygenase metabolites of arachi-
donic acid in neuronal transmembrane signalling. Trends Phar-
macol. Sci. 1990, 11, 367-373.
(15) Chen, Y. Q.; Liu, B.; Tang, D. G.; Honn, K. V. Fatty acid
modulation of tumor cell-platelet-vessel wall interaction. Cancer
Metastasis Rev. 1992, 11, 389-410.
(16) Chopra, H.; Timar, J .; Chen, Y. Q.; Rong, X.; Grossi, I. M.;
Fitzgerald, L. A.; Taylor, J . D.; Honn, K. V. The lipoxygenase
metabolite 12(S)-HETE induces a cytoskeleton-dependent in-
crease in surface expression of integrin RIIbâ3 on melanoma cells.
Int. J . Cancer 1991, 49, 774-786.
(17) Timar, J .; Chen, Y. Q.; Liu, B.; Bazaz, R.; Taylor, J . D.; Honn,
K. V. The lipoxygenase metabolite 12(S)-HETE promotes RIIbâ3
integrin-mediated tumor-cell spreading on fibronectin. Int. J .
Cancer 1992, 52, 594-603.
(18) Honn, K. V.; Tang, D. G.; Grossi, I.; Duniec, Z. M.; Timar, J .;
Renaud, C.; Leithauser, M.; Blair, I.; J ohnson, C. R.; Diglio, C.
A.; Kimler, V. A.; Taylor, J . D.; Marnett, L. J . Tumor cell-derived
12(S)-hydroxyeicosatetraenoic acid induces microvascular en-
dothelial cell retraction. Cancer Res. 1994, 54, 565-574.
(19) Tang, D. G.; Chen, Y. Q.; Honn, K. V. Arachidonate lipoxyge-
nases as essential regulators of cell survival and apoptosis. Proc.
Natl. Acad. Sci. U.S.A. 1996, 93, 5241-5246.
(20) Takahashi, Y.; Ueda, N.; Yamamoto, S. Two immunologically
and catalytically distinct arachidonate 12-lipoxygenase of bovine
platelets and leukocytes. Arch. Biochem. Biophys. 1988, 266,
613-621.
(21) Yamamoto, S. Mammalian lipoxygenases: molecular structures
and functions. Biochim. Biophys. Acta 1992, 1128, 117-131.
(22) Watanabe, T.; Medina, J . F.; Haeggstro¨m, J . Z.; Ra˚dmark, O.;
Samuelsson, B. Molecular cloning of a 12-lipoxygenase cDNA
from rat brain. Eur. J . Biochem. 1993, 212, 605-612.
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R. Arachidonate 12-lipoxygenase purified from porcine leuko-
cytes by immunoaffinity chromatography and its reactivity with
hydroperoxyeicosatetraenoic acids. J . Biol. Chem. 1986, 261,
16714-16721.
1
ether/EtOAc); H NMR (CDCl3) δ 8.00 (d, J ) 8.1 Hz, 2 H),
7.42 (d, J ) 8.1 Hz, 2 H), 4.63 (s, 2 H), 4.18 (t, J ) 2.1 Hz, 2
H), 3.90 (s, 3 H), 2.22 (tt, J 1 ) 6.9 Hz, J 2 ) 1.8 Hz, 2 H), 1.50
(m, 2 H), 1.30 (m, 8 H), 0.87 (t, J ) 6.9 Hz, 3 H); 13C NMR
(CDCl3) δ 166.89, 143.04, 129.64, 129.37, 127.47, 87.70, 75.44,
70.62, 58.13, 52.05, 31.72, 28.79, 28.56, 22.60, 18.73, 14.05.
4-[(2-Decyn yloxy)m eth yl]ben zoic Acid (3j). A mixture
of the above ester (300 mg, 1 mmol), water (2 mL), THF (2
mL), and 0.1 N NaOH (2 mL) was stirred for 30 h at 25 °C.
The resulting solution was acidified and extracted with ether
(25 mL). The ether extract was dried (MgSO4), filtered, and
concentrated by rotary evaporation to yield 3j as white crystals
(250 mg, 87%): mp 33-34 °C; IR (neat) 3400, 2921, 2851, 1453
1
cm-1; H NMR (CDCl3) δ 12 (s, 1 H), 8.1 (d, J ) 8.4 Hz, 2 H),
7.48 (d, J ) 8.4 Hz, 2 H), 4.68 (s, 2 H), 4.22 (t, J ) 1.8 Hz, 2
H), 2.24 (tt, J 1 ) 6.9 Hz, J 2 ) 1.8 Hz, 2 H), 1.52 (m, 2 H), 1.30
(m, 8 H); 13C NMR (CDCl3) δ 172.10, 144.29, 130.49, 128.69,
127.72, 127.63, 75.55, 70.74, 58.36, 31.85, 28.96, 28.92, 28.71,
22.73, 18.89, 14.19. Anal. (C18H24O3) C, H.
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E. Structure and chromosomal localization of human arachido-
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Su ppor tin g In for m ation Available: Details on the prepa-
ration of various lipophilic side chains and compound charac-
terization of 1a -d , 3a -c,f,g,i,k , 4, and 6-8 as well as various
key intermediates leading to these compounds (27 pages).
Ordering information can be found on any current masthead
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