Novel bioactive phospholipids: Practical total syntheses of products from the oxidation of arachidonic and linoleic esters of 2-lysophosphatidylcholine

Article abstract of DOI:10.1021/jo0105383

Total syntheses of nine novel phospholipids were accomplished to facilitate the identification and biological testing of compounds that are generated upon oxidative cleavage of arachidonate and linoleate esters of 2-lysophosphatidylcholine, the two most abundant polyunsaturated phospholipids in low-density lipoprotein. An efficient general synthesis exploiting 2-lithiofuran as a 4-oxo-2butenoyl carbanion equivalent provided phospholipids containing γ-keto-α,β-unsaturated carbonyl functional arrays. By exploiting facile cis-trans isomerizations, two commercially available cis alkenes, (2Z)-2-butene-1,4-diol and 2,5-dihydrofuran, could be employed as starting materials for preparing the Horner-Wadsworth-Emmons reagent 4-(diethoxyphosphoryl)-2E-butenal, a valuable building block for the synthesis of 2,4-dienals. The reagent was exploited in a total synthesis of 13-oxotridec-9E,11E-dienoic acid, confirming the identity of this product that is generated upon autoxidation of linoleic acid and by decomposition of 13-hydroperoxy-9,11-octadecadienoate (13HPODE), especially in the presence of redox active transition metal ions, cytochrome p-450, or hydroperoxide lyase.

Full text of DOI:10.1021/jo0105383

J . Org. Chem. 2002, 67, 3575-3584
3575
Novel Bioa ctive P h osp h olip id s: P r a ctica l Tota l Syn th eses of
P r od u cts fr om th e Oxid a tion of Ar a ch id on ic a n d Lin oleic Ester s of
2-Lysop h osp h a tid ylch olin e1
Mingjiang Sun, Yijun Deng, Eugenia Batyreva, Wei Sha, and Robert G. Salomon*
Department of Chemistry, Case Western Reserve University, Cleveland, Ohio 44106-7078
rgs@po.cwru.edu
Received May 29, 2001
Total syntheses of nine novel phospholipids were accomplished to facilitate the identification and
biological testing of compounds that are generated upon oxidative cleavage of arachidonate and
linoleate esters of 2-lysophosphatidylcholine, the two most abundant polyunsaturated phospholipids
in low-density lipoprotein. An efficient general synthesis exploiting 2-lithiofuran as a 4-oxo-2-
butenoyl carbanion equivalent provided phospholipids containing γ-keto-R,â-unsaturated carbonyl
functional arrays. By exploiting facile cis-trans isomerizations, two commercially available cis
alkenes, (2Z)-2-butene-1,4-diol and 2,5-dihydrofuran, could be employed as starting materials for
preparing the Horner-Wadsworth-Emmons reagent 4-(diethoxyphosphoryl)-2E-butenal, a valuable
building block for the synthesis of 2,4-dienals. The reagent was exploited in a total synthesis of
13-oxotridec-9E,11E-dienoic acid, confirming the identity of this product that is generated upon
autoxidation of linoleic acid and by decomposition of 13-hydroperoxy-9,11-octadecadienoate (13-
HPODE), especially in the presence of redox active transition metal ions, cytochrome p-450, or
hydroperoxide lyase.
In tr od u ction
firmed the presence of this oxPL in oxidized 1-palmitoyl-
2-arachidonoyl-sn-glycero-3-phosphocholine and demon-
strated that HOOA-PC dose-dependently activates endo-
thelial cells to bind monocytes and inhibits lipopolysac-
charide-induced E-selectin expression by human aortic
endothelial cells.5
We reported a total synthesis of the 9-hydroxy-13-
oxotridec-11-enoic acid ester of 2-lysoPC (HOT-PC), a
homologous δ-hydroxy-R,â-unsaturated aldehydic oxPL.4
A mechanism suggested previously for generation of the
corresponding free fatty acid from linoleic acid6 leads to
the expectation that HOT-PC is produced (Scheme 2)
through hydration of the 13-oxo-9,11-tridecadienoic acid
ester of 2-lysoPC (OTDE-PC, 6).
Oxidation of the arachidonic acid ester of 2-lysophos-
phatidylcholine (AA-PC) generates the 5-oxovaleric acid
ester of 2-lysoPC (OV-PC), a biologically active oxidized
phospholipid (oxPL). We assisted collaborators at UCLA
in confirming the structure of OV-PC and facilitated
exploration of the biological activities of this oxPL by
providing samples through a convenient and unambigu-
ous total synthesis.2 A minor biologically active product
generated during the synthesis was isolated and char-
acterized as the monoester of glutaric acid with 2-lysoPC
(G-PC). G-PC2 is also generated upon oxidation of AA-
PC (Scheme 1).
These studies piqued our interest in oxPL and their
biological activities. They inspired a mechanism-based
hypothesis (Scheme 1) that oxidation of AA-PC generates
the 5-hydroxy-8-oxo-6-octenoic acid ester of 2-lysoPC
(HOOA-PC) and oxidation of the linoleic acid ester of
2-lysoPC (LA-PC) generates the 9-hydroxy-12-oxo-10-
dodecenoic acid ester of 2-lysoPC (HODA-PC). We devel-
oped immunoassays to detect protein adducts derived
from HOOA-PC and HODA-PC and used them to obtain
evidence for the formation of such γ-hydroxy-R,â-unsat-
urated aldehydic oxPL in vivo.3 We also devised total
syntheses of HOOA-PC and HODA-PC.4 The synthetic
HOOA-PC facilitated LC-MS experiments that con-
Recently, our mechanistic hypothesis-driven quest to
identify novel oxPL converged with an exploratory effort
to isolate and identify biologically active components in
the product mixture generated by myeloperoxidase-
mediated oxidation of phospholipids. Guided by a bioas-
say that will be reported elsewhere,7 we fractionated the
oxidized lipids by reversed-phase HPLC and confirmed
by LC-MS that HODA-PC and HOOA-PC are bioactive
components in the oxPL mixtures generated by oxidation
of LA-PC and AA-PC, respectively. Other more and less
polar bioactive phospholipids were also detected. In view
of the confirmed biological activities of the hydroxy
aldehydes HODA-PC and HOOA-PC, we postulated that
the less polar oxPL are keto aldehydes (Scheme 1) KOOA-
PC (3a ) and KODA-PC (3b). These might arise through
* To whom correspondence should be addressed. Tel: 216-368-2592.
Fax: 216-368-3006.
(1) Total Synthesis of Oxidized Phospholipids. 4. For previous papers
in this series, see refs 2, 4, and 10.
(2) Watson, A. D.; Leitinger, N.; Navab, M.; Faull, K. F.; Horkko,
S.; Witztum, J . L.; Palinski, W.; Schwenke, D.; Salomon, R. G.; Sha,
W.; Subbanagounder, G.; Fogelman, A. M.; Berliner, J . A. J . Biol.
Chem. 1997, 272, 13597-607.
(5) Subbanagounder, G.; Deng, Y.; Borromeo, C.; Dooley, A. N.;
Berliner, J . A.; Salomon, R. Vasc. Pharmacol. 2002, in press.
(6) Spiteller, G. Chem. Phys. Lipids 1998, 95, 105-62.
(7) Podrez, E. A.; Batyreva, E.; Shen, Z.; Zhang, R.; Deng, Y.; Sun,
M.; Guigu, B.; Finton, P. J .; Shen, L.; Febbraio, M.; Hajjar, D. P.;
Silverstein, R. L.; Hoff, H. F.; Salomon, R. G.; Hazen, S. L. J . Biol.
Chem. 2002, submitted.
(3) Kaur, K.; Salomon, R. G.; O’Neil, J .; Hoff, H. F. Chem. Res.
Toxicol. 1997, 10, 1387-96.
(4) Deng, Y.; Salomon, R. G. J . Org. Chem. 2000, 65, 6660-6665.
10.1021/jo0105383 CCC: $22.00 © 2002 American Chemical Society
Published on Web 05/07/2002

3576 J . Org. Chem., Vol. 67, No. 11, 2002
Sun et al.
Sch em e 1
Sch em e 2
Sch em e 3
Sch em e 4
oxidation of the corresponding alcohols or dehydration
of the corresponding hydroperoxides, HPODA-PC and
HPOOA-PC, respectively. The production of an analogous
compound, 4-oxo-2-nonenal, by Fe2+-mediated fragmen-
tation of 13(S)-hydroperoxy-(Z,E)-9,11-octadecadienoic
acid was reported recently.8 The proclivity of aldehydes
toward oxidation to carboxylic acids, e.g., the conversion
of OV-PC into G-PC,2 led us to postulate that the more
polar oxPL are the corresponding hydroxy acids or keto
acids (Scheme 1). We now report practical total syntheses
of KOOA-PC (3a ), KODA-PC (3b), KOdiA-PC (4a ), KD-
diA-PC (4b) HOdiA-PC (5a ), HDdiA-PC (5b), as well as
the 9-oxononanyl ester of 2-lysoPC (ON-PC, 1), the
monoester of azeleic acid with 2-lyso-PC (A-PC, 2), and
OTDE-PC (6) the putative precursor of HOT-PC (Scheme
2).
uisite 2-substituted furans are readily available by alkyl-
ation of 2-furyllithium with appropriate masking of the
carboxyl group (Scheme 3).
The carbon skeletons of the latent keto acids 8 were
assembled by the coupling of furyl-lithium with the
TBDMS ethers 9a and 9b of 4-iodobutanol or 8-bromo-
octanol, respectively (Scheme 4).9 The requsite 4-iodo-
butanol TBDMS ether is readily available from tetra-
hydrofuran by reaction with NaI and TBDMSCl.10 The
TBDMS ether (9b) of 8-bromooctanol is obtained by
Resu lts a n d Discu ssion
γ-Keto-r,â-Un sa tu r a ted Ald eh yd ic P h osp h olip id s
KODA-P C a n d KOOA-P C. Furans 8 bearing an ω-
carboxyalkyl substituent at the 2-position are latent
ω-carboxy-γ-keto-R,â-unsaturated aldehydes 7. The req-
(9) Kobayashi, Y.; Nakano, M.; Kumar, G. B.; Kishihara, K. J . Org.
Chem. 1998, 63, 7505-7515.
(10) Deng, Y.; Salomon, R. G. J . Org. Chem. 1998, 63, 7789-7794.
(8) Lee, S. H.; Blair, I. A. Chem. Res. Toxicol. 2000, 13, 698-702.

Novel Bioactive Phospholipids
Sch em e 5
J . Org. Chem., Vol. 67, No. 11, 2002 3577
Sch em e 6
Sch em e 7
bromodehydroxylation of the corresponding monosilyl
ether of 1,8-octanediol with DEAD, Ph3P, and ZnBr2. The
requisite monosilyl ether was produced by the reaction
of TBDMSCl with the sodium monoalkoxide of 1,8-
octanediol.10 The silyl ethers 10 were desilylated with
fluoride affording primary alcohols 11, from which furyl
acids 8 were produced by oxidation with pyrdinium
dichlorochromate (PDC). Esterification of the furyl acids
8 with L-R-lyso-phosphatidylcholine (lyso-PC) from egg
albumin was accomplished in good yield with dicyclo-
hexylcarbodiimide (DCC) and N,N-dimethylaminopyri-
dine (DMAP). Aqueous N-bromosuccinamide (NBS)-
promoted oxidative ring opening9 of the furans produced
the desired ketoalkenals, KOOA-PC (3a ) and KODA-PC
(3b) without oxidation of the sensitive aldehyde group.
The yields were improved to 60-68% from 35% when the
reaction time was increased from 3 to 6 h. In contrast,
the aldehyde apparently did not survive oxidative ring
opening with m-chloroperbenzoic acid at room tempera-
ture in chloroform.11
r,â-Un sa tu r a ted Dica r boxylic P h osp h olip id s HD-
d iA-P C, HOd iA-P C, KDd iA-P C, a n d KOd iA-P C. The
R,â-unsaturated dicarboxylic acid phospholipid mono-
esters HDdiA-PC (5b), HOdiA-PC (5a ), KDdiA-PC (4b)
and KOdiA-PC (4a ) were obtained by selective oxidation
of the corresponding aldehydes (Scheme 5) with sodium
chlorite in the presence of 2-methyl-2-butene and NaH2-
PO4 in tert-butyl alcohol and water (5:1, v/v).12 The
reactions must be carefully monitored. If an inadequate
amount of 2-methyl-2-butene is present, oxidative frag-
mentation ensues, delivering shorter chain carboxylic
acids G-PC2 and A-PC (2).
3-phosphatidylcholine (ON-PC, 1) is readily available by
deprotection of a stable precursor, dimethyl acetyl 17,
that was prepared by esterification of 2-lysoPC with 9,9-
dimethoxynonanoic acid (16). The acid 16 is readily
obtained from methyl 9Z-octadecenoate in three steps:
ozonolysis,13,14 protection of the resulting aldehyde 14 as
an acetal 15,15 and hydrolysis of the ester group in 15.
The oxidized phospholipid ON-PC undergoes gradual
oxidation to form 1-palmitoyl-2-azeleyl-sn-glycero-3-phos-
phatidylcholine (A-PC, 2). This monoester of azeleic acid
with 2-lysoPC was also prepared by the reaction of 2-lyso-
PC and nonanedioic anhydride, which is readily obtained
from azeleic acid and acetyl chloride according to the
reported procedure,16 catalyzed by DMAP (Scheme 7).
A 13-Oxotr ideca-9,11-dien oic Acid Ester of 2-Lyso-
P C (OTDE-P C, 6). The R,â,γ,δ-unsaturated aldehyde
functional array is a common theme in oxidized lipids
that are produced by peroxidation of polyunsaturated
fatty acids. Thus, 2-trans-4-cis-2,4-decadienal is a major
early oxidation product in the autoxidation of low-density
lipoprotein (LDL), and its isomer, 2-trans-4-trans-2,4-
decadienal becomes the main product within 2h.17 Fur-
thermore, 13-oxo-9,11-tridecadienoic acid (OTDEA, 18)
is a major product of both enzymatic and nonenzymatic
oxidation of linoleic acid (LA).18 Hydroperoxyoctadecadi-
enoates (HPODEs) are the main primary peroxidation
products from LA. One of the primary decomposition
products from 13-HPODE is 13-OTDEA (18).6 HPODEs
are unstable, especially in the presence of redox active
transition metal ions.19,20 The formation of aldehydes
9-Oxon on a n oyl a n d Azeleyl P h osp h olip id s. In
view of its easy removal under mild conditions with an
acidic resin, e.g., Amberlyst-15, a dimethyl acetal was
exploited as the aldehyde protecting group in a synthesis
(Scheme 6) of the 9-oxononanoyl ester of 2-lysoPC (ON-
PC, 1). Thus, 1-palmitoyl-2-(9-oxononanoyl)-sn-glycero-
(13) Duffault, J . M.; Einhorn, J .; Alexakis, A. Tetrahedron Lett. 1991,
32, 3701-3704.
(14) Crombie, L.; Holloway, S. J . J . Chem. Soc., Perkin Trans. 1
1985, 2425-2434.
(15) Taylor, E. C.; Chiang, C. S. Synthesis 1977, 467.
(16) Anderlini, F. Gazz. Chim. Ital. 1894, 24I, 476-480.
(17) Gardner, H. W. Free Radical Biol. Med. 1989, 7, 65-86.
(18) Kaneko, T.; Honda, S.; Nakano, S.; Matsuo, M. Chem. Biol.
Interact. 1987, 63, 127-37.
(11) Wu, H.-J .; Lin, C.-C. J . Org. Chem. 1996, 61, 3820-3828.
(12) Kraus, G. A.; Taschner, M. J . J . Org. Chem. 1980, 45, 1175-
1176.

3578 J . Org. Chem., Vol. 67, No. 11, 2002
Sun et al.
Sch em e 8
Sch em e 9
from HPODEs can occur by reaction with Fe2+ or Cu+ to
produce alkoxy radicals that afford aldehydes upon
â-scission. Such a mechanism would produce 2,4-deca-
dienal17 and OTDEA (18)21 from 9-HPODE and 13-
HPODE respectively (Scheme 8). Reductive â-scission of
13-HPODE catalyzed by cytochrome P-450 generates a
3:1 mixture of 9-trans-11-trans-13-OTDEA and 9-trans-
11-cis-13-OTDEA.3 The homolytic hydroperoxide lyase
oxidation of 13-HPODE generates similar amounts of the
11-cis and 11-trans isomers.22
Sch em e 10
In vivo, fatty acids occur mainly as esters of cholesterol
or glycerol. HPODE esters of 2-lysoPC are abundant in
human blood plasma and oxidized LDL.23,24 However,
very little information is available about the secondary
PC-containing products that are formed by decomposition
of HPODE-PCs. To facilitate their structural and biologi-
cal characterization, we devised total syntheses of OT-
DEA (18) and its 2-lysoPC ester, OTDE-PC (6). A
convergent strategy for the synthesis of OTDE-PC (6) is
outlined in Scheme 9. The carbon skeleton of the target
should be readily accessible by the Horner-Wadsworth-
Emmons condensation of a phosphoryl imine 19 derived
from the trans crotonaldehyde 20E.25 The key intermedi-
ate in the synthesis, the phosphoryl unsaturated alde-
hyde 20E, was prepared previously from 1,3-butadiene.26
An alternative synthesis from commercially available cis-
2-butene-1,4-diol seemed feasible in view of the likely
facile isomerization of a cis-crotonaldehyde intermediate
20Z to the trans isomer.27 An especially efficient synthe-
sis was ultimately devised that starts with 2,5-dihydro-
furan (DHF).
Sch em e 11
A P r eviou s Syn th esis of th e P h osp h or yl Im in e 19.
The Horner-Wadsworth-Emmons reagent 19, derived
from 4-(diethoxyphosphoryl)-2E-butenal (20E), is a useful
building block for synthesis of conjugated dienals. Previ-
ously, imine 19 was prepared from butadiene as outlined
in Scheme 10.26 The aldehyde 20E was protected as an
imine by treatment with cyclohexylamine in the presence
of molecular sieves,26 which serve as catalyst and dehy-
drating agent.28
Alt er n a t ive Syn t h eses of P h osp h or yl Alk en a l
20E. We developed an alternative synthesis of E-alde-
hyde 20E that relies upon cis-trans isomerization of a
cis-crotonaldehyde intermediate 20Z (Scheme 11).27 Treat-
ment of cis-2-butene-1,4-diol with TBDMSCl, DMAP, and
Et3N provides the monosilyl ether 21.29 Conversion of the
(19) Esterbauer, H.; Schmidt, R.; Hayn, M. Adv. Pharmacol. 1997,
38, 425-56.
(20) Gardner, H. W.; Kleiman, R.; Weisleder, D. Lipids 1974, 9, 696-
706.
(21) Garssen, G. J .; Vliegenthart, J . F.; Boldingh, J . Biochem. J .
1971, 122, 327-32.
(22) Kondo, Y.; Hashidoko, Y.; Mizutani, J . Biochim. Biophys. Acta
1995, 1255, 9-15.
(23) Steinbrecher, U. P.; Parthasarathy, S.; Leake, D. S.; Witztum,
J . L.; Steinberg, D. Proc. Natl. Acad. Sci. U.S.A. 1984, 81, 3883-7.
(24) Noguchi, N.; Numano, R.; Kaneda, H.; Niki, E. Free Radical
Res. 1998, 29, 43-52.
(25) Boutagy, J .; Thomas, R. Chem. Rev. 1974, 89, 437-443.
(26) Kann, N.; Rein, T.; Akermark, B.; Helquist, P. J . Org. Chem.
1990, 55, 5312-5323.
(28) Taguchi, K.; Westheimer, F. H. J . Org. Chem. 1971, 36, 1570-
1572.
(29) Chudhary, S. K.; Hernandez, O. Tetrahedron Lett. 1979, 20,
99-102.
(27) Mcgreer, D. E.; Page, B. D. Can. J . Chem. 1969, 47, 866-867.

Novel Bioactive Phospholipids
Sch em e 12
J . Org. Chem., Vol. 67, No. 11, 2002 3579
obtained in 70% overall yield by flash chromatography
that was accompanied by hydrolysis of 26.26 The dienal
was then protected as a dimethyl acetal 28 with Taylor
reagent (Montmorillonite K-10/trimethyl orthoformate).15
13-Oxotridec-9E,11E-dienoic acid (OTDEA, 18) was pro-
duced in 82% yield by hydrolysis of methyl ester 28 with
NaOH, followed by acidification with 2 N HCl at room
1
temperature.33 The H NMR spectrum of this authentic
sample of OTDEA agreed well with that reported for a
Sch em e 13
dienal acid obtained by lipid oxidation.22,34
A synthesis of OTDE-PC (6) was pursued by coupling
OTDEA (18) with 2-lysoPC (Scheme 13). More carefully
controlled hydrolysis of 28 delivered the dimethyl acetal
29. Ice-cold 0.5 N HCl was added to the basic solution at
0 °C until pH 4 was reached to avoid the hydrolysis of
the acetal. Both aldehydic acid (OTDEA, 18) and acetal
acid 29 were readily esterified with 2-lyso-PC in the
presence of DCC and DMAP in CHCl3 to deliver the
desired phospholipid OTDE-PC after acidic work up.
However, the esterification of 29 with lyso-PC generally
provided a higher yield, 70-80% versus 50% from OT-
DEA (18). Owing to its reactivity as a Michael acceptor,
trans,trans-2,4-decadienal (see Scheme 8) reacts with
glutathione,17 and is highly toxic to human diploid
fibroblast cells.35 Because its Michael adduction chem-
istry should be analogous to that of 2-trans-4-trans-2,4-
decadienal, OTDEA (18) and the derived phospholipid
OTDE-PC (6) are likely to exhibit similar biological
activities. The total syntheses reported above will facili-
tate the examination of such questions as well as the
detection and quantification of OTDE-PC (6) in vivo.
Arachidonate and linoleate esters of 2-lysophosphatidyl-
choline are the two most abundant polyunsaturated
phospholipids in low-density lipoprotein (LDL). Oxidation
of LDL has been implicated in the etiology of athero-
sclerosis. Studies exploiting authentic samples of the
novel oxPLs described above to examine their generation
by oxidation of AA-PC and LA-PC, their presence in
atherosclerotic plaques, and their biological activities will
be reported elsewhere.5,7
remaining hydroxyl group into the bromide 22 was
accomplished in 92% yield by treatment with bis-(1,2-
diphenylphosphino)ethane (DIPHOS) and CBr4.30 Reac-
tion of the bromide 22 with triethyl phosphite under
Arbuzov conditions provided the phosporyl TBDMS ether
23Z.26 Hydrolytic removal of the TBDMS protecting
group with 2 N H2SO4, followed by oxidation of the
corresponding alcohol 24 with J ones reagent31 was ac-
companied by partial isomerization to give the phos-
phoryl aldehyde 20 as a 3:1 mixture of E and Z isomers.
Isomerization of 20Z to 20E was completed with acid
catalysis.27 A solution of the cis/trans mixture in acetone
was refluxed (60 °C) in the presence of a trace of 2 N
H2SO4 for 30-60 min to afford 20E in 90% yield (E/Z
>99:1).
An even more concise synthesis that delivers the trans
phosphonate 23 (E/Z ) 4:1) was accomplished by the
reaction of 2,5-DHF with TBDMSCl, NaI, and DMAP
(Scheme 12). The resulting desymmetrization converts
one ether linkage into an activated electrophile while
protecting the remaining oxygen functionality as a silyl
ether and the cis geometry of the CdC bond was
isomerized (trans/cis ) 95:5). This is an especially
convenient route to the allylic iodide 25. Phosphonate 23
was obtained in two steps and 90% yield.
Exp er im en ta l P r oced u r es
Gen er a l Meth od s. Proton magnetic resonance (1H NMR)
spectra were recorded on a Varian Gemini spectrometer
operating at 200, 300, or 600 MHz. Proton chemical shifts are
reported in parts per million (ppm) on the δ scale relative to
solvent. Carbon magnetic resonance (13C NMR) spectra were
recorded on a Varian Gemini spectrometer operating at 75
MHz.
Thin-layer chromatography (TLC) was performed on glass
plates precoated with silica gel (Kieselgel 60 F254, E. Merck,
Darmstadt, West Germany); Rf values are quoted for plates
of thickness 0.25 mm. The plates were visualized by viewing
under short-wavelength UV light or by treatment with iodine.
Flash column chromatography was performed on 230-400
mesh silica gel supplied by E. Merck. High-performance liquid
chromatography (HPLC) was performed with HPLC grade
solvents using a Waters M600A solvent delivery system and
a Waters U6K injector. The eluants were monitored using a
SEDEX 55 evaporative light scattering detector and an ISCO
V4 UV-vis detector. Analytical RP-HPLC was performed on
a Phenomenex LUNA C18 (2) column (4.6 mm i.d. × 25 cm).
A synthesis of 13-oxotridec-9E,11E-dienoic acid (OT-
DEA, 18) was devised based on the Horner-Wadsworth-
Emmons reagent 19 (Scheme 13). Condensation of alde-
hyde 1432 with phosphoryl imine 19 (LDA/THF/-78 °C)
delivered the dienal imine 26. The dienoate 27 was
(33) Nakamura, Y.; Ito, A.; Shin, C. Bull Chem. Soc. J pn. 1990, 67,
2151-2161.
(30) Stowell, J .; Keith, D. Synthesis 1979, 133-134.
(31) Harding, K. E.; May, L. M.; Dick, K. F. J . Org. Chem. 1975,
40, 1644-1665.
(32) Scott, R. W.; Epperson, J .; Heathcock, C. H. J . Org. Chem. 1998,
63, 5001-5012.
(34) Vaz, A. D.; Roberts, E. S.; Coon, M. J . Proc. Natl. Acad. Sci.
U.S.A. 1990, 87, 5499-503.
(35) Spiteller, D.; Spiteller, G. Angew Chem., Int. Ed. Engl. 2000,
39, 583-585.

3580 J . Org. Chem., Vol. 67, No. 11, 2002
Sun et al.
Semipreparative RP-HPLC was performed on a Phenomenex
104.5, 63.0, 32.7, 29.3, 29.1, 28.0, 27.9, 25.7. HRMS (EI): m/z
calcd for C12H20O2 (M+) 196.1463, found 194.1462.
LUNA C18 (2) column (10 mm i.d. × 25 cm).
4-(2-F u r yl)bu ta n oic Acid (12a ). PDC (316 mg, 0.84 mmol)
was added to the solution of alcohol 11a (20 mg, 0.14 mmol)
in DMF (0.5 mL). The resulting mixture was stirred for 20 h.
The solution was diluted by saturated NH4Cl aqueous solution
(5 mL) and extracted with ethyl ether. The organic extract was
washed with water (pH 3) and dried with MgSO4. The solvent
was removed on a rotary evaporator. The residue was chro-
matographed on a on a silica gel column (50% ethyl acetate in
hexanes; TLC, Rf ) 0.2) to give acid 12a (18 mg, 84%). 1H NMR
(CDCl3, 200 MHz): δ 7.29 (dd, J ) 1.9, 0.7 Hz, 1H), 6.26 (dd,
J ) 3.1, 1.9 Hz, 1H), 6.00 (dd, J ) 3.1, 0.8 Hz, 1H), 2.68 (t, J
) 7.3, 2H), 2.39 (t, J ) 7.4, 2H), 1.89-2.05 (m, 2H). 13C NMR
(CDCl3, 75 MHz): δ 180.0, 154.8, 110.0, 141.1, 110.1, 105.5,
33.2, 27.1, 23.0. HRMS (EI): m/z calcd for C8H10O3 (M+)
154.0630, found 154.0631.
4-Iod o-1-(1,1,2,2-tetr m eth yl-1-sila p r op oxy)bu ta n e (9a ).
This compound was prepared according to the procedure
reported previously.10 1H NMR (300 MHz): δ 3.61 (t, J ) 6.1
Hz, 2H), 3.20 (t, J ) 7.0 Hz, 2H), 1.8-1.9 (m, 2H), 1.4-1.6
(m, 2H), 0.87 (s, 9H), 0.02 (s, 6H).
8-Br om o-1-(1,1,2,2-tetr m eth yl-1-silapr opoxy)octan e (9b).
This compound was prepared according to the procedure
reported previously.10 1H NMR (300 MHz): δ 3.57 (t, J ) 6.4
Hz, 2H), 3.38 (t, J ) 6.8 Hz, 2H), 1.83 (4H), 1.35-1.55 (4H),
1.20-1.40 (4H), 0.89 (s, 9H), 0.02 (s, 6H).
4-(2-F u r yl)-1-(1,1,2,2-t e t r m e t h yl-1-sila p r op oxy)b u -
ta n e (10a ). n-Butyllithium (9.5 mL, 1.2 M in hexane, 11.4
mmol) was added dropwise to an ice-cold solution of furan (1.5
mL, 15.6 mmol) and bipyridine (10 mg) in dry THF (20 mL)
under argon. The resulting brown solution was stirred for 1 h
to generate 2-furyllithium. Then 4-iodo-1-(1,1,2,2-tetrmethyl-
1-silapropoxy)butane (9a , 1.19 g, 3.8 mmol) in THF (2 mL)
was added. The solution was kept at 0 °C for 1 h and then
warmed to room temperature. After 3 h, the reaction was
quenched by the addition of saturated NH4Cl. The mixture
was extracted with hexane. The organic extract was dried with
MgSO4 and concentrated with a rotary evaporator to give a
residue that was purified by flash chromatography on a silica
gel column (2% ethyl acetate in hexanes, Rf ) 0.35) to afford
8-(2-F u r yl)octa n oic Acid (12b). PDC (2.19 g, 6.3 mmol)
was added to a solution of alcohol 11b (206 mg, 1.05 mmol) in
DMF (3 mL). The resulting mixture was stirred for 18 h. The
solution was diluted by saturated NH4Cl aqueous solution (30
mL) and extracted with ethyl ether. The organic extract was
washed with water (pH 3) and dried with MgSO4. The solvent
was removed on a rotary evaporator. The residue was chro-
matographed on a on a silica gel column (45% ethyl acetate in
1
hexanes; TLC, Rf ) 0.32) to give acid 12b (172 mg, 78%). H
NMR (CDCl3, 200 MHz): δ 7.28 (dd, J ) 1.9, 0.8 Hz, 1H), 6.26
(dd, J ) 3.1, 1.9 Hz, 1H), 5.95 (d, J ) 3.1, 1H), 2.59 (t, J ) 7.5,
2H), 2.33 (t, J ) 7.6, 2H), (4H). 13C NMR (CDCl3, 75 MHz): δ
180.4, 156.4, 140.6, 110.0, 104.6, 34.0, 28.9, 27.9, 27.8, 24.6.
HRMS (EI): m/z calcd for C12H18O3 (M+) 210.1256, found
210.1259.
1
10a (819 mg, 85%) as a colorless oil. H NMR (200 MHz): δ
7.28 (d, J ) 2 Hz, 1 H) 6.27 (dd, J ) 3.2, 2 Hz, 1 H), 5.98 (d,
J ) 3.2 Hz, 1 H), 3.64 (t, J ) 6.2 Hz, 2H), 2.65 (t, J ) 7.2 Hz,
2 H), 1.5-1.7 (4 H), 0.91 (s, 9 H). 0.06 (s, 6 H). C NMR (75
MHz): δ 156.2, 140.6, 109.9, 104.6, 62.7, 32.2, 32.2., 27.7, 25.9,
24.36, 18.3, -5.3.
1-P a lm itoyl-2-(4-(2-fu r yl)bu ta n oyl)-sn -glycer o-3-p h os-
p h a tid ylch olin e (13a ). A mixture of furyl acid 12a (30 mg,
0.19 mmol) and 1-palmitoyl-2-lyso-sn-glycero-3-phosphatidyl-
choline (50 mg,0.1 mmol), which was dried on a vacuum pump
(0.1 mmHg) equipped with a dry ice-acetone trap for 10 h at
room temperature, was dissolved in dry CHCl3 (2 mL, shaken
with P2O5 for 0.5 h and distilled). Dicyclohexylcarbodiimide
(DCC, 120 mg, 0.6 mmol) and N,N-dimethylaminopyridine
(DMAP, 12 mg, 0.1 mmol) were added. The mixture was stirred
for 96 h under nitrogen. The mixture was concentrated, and
the residue was chromatographed on silica with CHCl3/MeOH/
H2O (16/9/1) to produce the furyl phospholipid 13a (56 mg,
4-(2-F u r yl)bu ta n -1-ol (11a ). n-Bu4NF (6.9 mL, 1 M in
THF, 6.9 mmol) was added dropwise to a stirred solution of
the silyl ether 10a (659 mg, 2.73 mmol) in dry THF (5 mL).
The resulting solution was stirred overnight under nitrogen.
Water (4 mL) was then added. The suspension was extracted
with ethyl ether. The organic extract was dried with sodium
sulfate and concentrated. The residue was then purified by
flash chromatography on a silica gel column (20% ethyl acetate
in hexanes; TLC, Rf ) 0.4) to afford 5a (366 mg, 96%). 1H NMR
(200 MHz): δ 7.27 (dd, J ) 1.9, 0.8 Hz, 1H), 6.25 (dd, J ) 3.1,
0.9 Hz, 1H), 3.64 (t, J ) 6.4, 2H), 2.64 (t, J ) 7.3, 2H), 1.4-
1.8 (4H). 13C NMR (CDCl3, 75 MHz): δ 155.9, 140.7, 110.0,
104.7, 62.3, 32.0, 27.6, 24.2. HRMS (EI): m/z calcd for C8H12O2
(M+) 140.0837, found 140.0837.
1
88%): H NMR (CDCl3, 300 MHz) δ 7.29 (d, J ) 1.9, Hz, 1H),
6.25 (dd, J ) 3.1, 1.9 Hz, 1H), 5.99 (dd, J ) 3.1, 1H), 5.18 (m,
1H), 4.36 (dd, J ) 12.2, 2.8 Hz, 1H), 4.25 (bm, 2H), 4.10 (dd,
J ) 12.2, 7.4, 1H), 3.91 (t, J ) 6 Hz, 2H), 3.76 (bm, 2H); 3.33
(bs, 9H), 2.64 (t, J ) 7.4 Hz, 2H), 2.34 (t, J ) 7.3 Hz, 2H),
1.8-2.1 (m, 2H), 1.4-1.6 (m, 2H), 1.23 (24H), 0.86 (t, J ) 6.7
8-(2-F u r yl)octa n -1-ol (11b). n-Butyllithium (3.9 mL, 1.2
M in hexane, 4.7 mmol) was added dropwise to the ice-cold
solution of furan (0.6 mL, 15.6 mmol) and bipyridine (5 mg)
in dried THF (10 mL) under argon. The resulting brown
solution was stirred for 1 h to generate 2-furyllithium.
8-Bromo-1-(1,1,2,2-tetrmethyl-1-silapropoxy)octane (9b, 0.5 g,
1.55 mmol) in THF (2 mL) was added to the solution. The
solution was kept at 0 °C for 1 h and then warmed to room
temperature. After 7 h, the reaction was quenched by the
addition of saturated NH4Cl. The mixture was extracted with
hexane. The combined organic layer was dried with MgSO4
and concentrated with a rotary evaporator to give a residue
Hz, 3H). HRMS (FAB): m/z 632.3927 (MH+) calcd for C32H59
-
NO9P, found 632.3934.
1-P a lm itoyl-2-(8-(2-fu r yl)octa n oyl)-sn -glycer o-3-p h os-
p h a tid ylch olin e (13b). A mixture of furyl acid 12b (84 mg,
0.4 mmol) and 1-palmitoyl-2-lyso-sn-glycero-3-phosphatidyl-
choline (100 mg, 0.2 mmol), which was dried on a vacuum
pump (0.1 mmHg) equipped with a dry ice-acetone trap for 6
h at room temperature, was dissolved in dry CHCl3 (4 mL,
shaken with P2O5 for 0.5 h and distilled). Dicyclohexylcarbo-
diimide (DCC, 240 mg, 1.2 mmol) and N,N-dimethylamino-
pyridine (DMAP, 24 mg, 0.2 mmol) were added. The mixture
was stirred for 96 h under nitrogen. The mixture was concen-
trated, and the residue was purified by flash chromatography
on silica with CHCl3/MeOH/H2O (16/9/1) to produce the furyl
phospholipid 13b (110 mg, 79%): 1H NMR (CDCl3, 300 MHz)
δ 7.22 (d, J ) 1.9, Hz, 1H), 6.20 (dd, J ) 3, 1.9 Hz, 1H), 5.92
(d, J ) 3, 1H), 5.14 (m, 1H), 4.34 (dd, J ) 12.2, 2.8 Hz, 1H),
4.25 (bm, 2H), 4.10 (dd, J ) 12.2, 7.4, 1H), 3.91 (m, 2H), 3.76
(bm, 2H), 3.35 (bs, 9H), 2.54 (t, J ) 7.4 Hz, 2H), 2.2-2.4 (4H),
1.5-1.6 (6H), 1.1-1.3 (30H), 0.83 (t, J ) 6.30 Hz, 3H). HRMS
(FAB): m/z 688.4553 (MH+) calcd for C36H67NO9P, found
688.4532.
1
(10b). H NMR (CDCl3, 200 MHz): δ 7.29 (d, J ) 2 Hz, 1 H),
6.27 (dd, J ) 3.2, 2 Hz, 1 H), 5.96 (d, J ) 3.2 Hz, 1 H), 3.60 (t,
J ) 6.2 Hz, 2H), 2.62 (t, J ) 7.2 Hz, 2 H), 1.5-1.7 (12 H), 0.91
(s, 9 H). 0.06 (s, 6 H). 13C NMR (CDCl3, 75 MHz): δ 156.7,
140.7, 110.1, 104.6, 63.4, 32.9, 29.4, 29.2, 28.1, 28.0, 26.1, 25.8,
18.5, -5.2. Without further purification, THF (5 mL) and Bu4-
NF (6 mL, 1 M in THF, 6 mmol) were sequentially added to
the residue. After 5 h, aqueous NH4Cl (10 mL) was added to
quench the reaction. The resulting mixture was extracted with
ethyl ether. The combined organic layer was concentrated and
purified on a silica gel column (25% ethyl acetate in hexanes;
1
TLC, Rf ) 0.24) to give furyl alcohol (11b, 257 mg, 84%). H
NMR (CDCl3, 200 MHz): δ 7.27 (dd, J ) 1.9, 0.8 Hz, 1H), 6.25
(dd, J ) 3.1, 1.8 Hz, 1H), 5.94 (dd, J ) 3.1, 0.8 Hz, 1H), 3.61
(t, J ) 6.6, 2H), 2.59 (t, J ) 7.5, 2H), 1.45-1.71 (4H), 1.30-
1.34 (12H). 13C NMR (CDCl3, 75 MHz): δ 156.5, 140.6, 110.0,
1-P a lm it oyl-2-(5-oxo-8-oxooct -6-en oyl)-sn -glycer o-3-
p h osp h a tid ylch olin e (KOOA-P C, 3a ). N-Bromosuccinimide
(10 mg, 0.05 mmol) and pyridine (5.8 mL, 0.07 mmol) were

Novel Bioactive Phospholipids
J . Org. Chem., Vol. 67, No. 11, 2002 3581
sequentially added to a solution of furyl phosphatidylcholine
13a (22 mg, 0.035 mmol) in THF/acetone/water (5:4:2) at -20
°C. The resulting mixture was stirred for 1 h at this temper-
ature and then kept at room temperature for 3 h. The solvent
was then removed quickly by rotary evaporation, and the
residue was chromatographed on a silica gel column (CHCl3/
MeOH/H2O ) 16/9/1) affording a mixture (24 mg) that
contained about 80% KOOA-P C (3a ) as determined by
reversed-phase HPLC. A second flash chromatography was
necessary to produce pure KOOA-P C (3a ,17 mg, 68%). 1H
NMR (CDCl3, 600 MHz): δ 9.77 (d, J ) 7.2 Hz, 1H), 6.91 (d,
J ) 16.8 Hz, 1H), 6.81 (dd, J ) 16.8, 7.2 Hz, 1H), 5.21 (m,
1H), 4.32 (3H), 4.12 (m, 1H), 3.98 (m, 2H), 3.79 (m, 2H), 3.13
(bs, 9H), 2.85 (2H, d, J ) 7.1 Hz), 2.2-2.5 (4H), 1.9-2.0 (m,
2H), 1.5-1.6 (2H), 1.1-1.3 (24H), 0.83 (t, J ) 6.3 Hz, 3H).
HRMS (FAB): m/z 648.3876 (MH+) calcd for C32H59NO10P,
found 648.3856.
1-P a lm it oyl-2-(5-h yd r oxy-7-ca r b oxyh ep t -6-en oyl)-sn -
glycer o-3-p h osp h a tid ylch olin e (HOd iA-P C, 5a ). To a mag-
netically stirred solution of HOOA-PC (7.4 mg, 0.011 mmol)
in t-BuOH-H2
O (5:1, v/v, 0.3 mL) was added a solution
containing NaH2PO4 (4.5 mg, 0.017 mmol), 2-methyl-2-butene
(33 µL, 0.07 mmol, 2 M solution in THF), and NaClO2 (3.1
mg, 0.034 mmol) in t-BuOH-H2O (5:1, v/v, 0.3 mL). The
resulting mixture was stirred for 2 h at room temperature
under argon. The solvent was then removed by rotary evapo-
ration. The residue was extracted with 4:1 CHCl3/MeOH. The
crude product was purified by flash chromatography on a silica
gel column (CHCl3/MeOH/H2O, 15:9:1; TLC, Rf ) 0.15) to give
1
HOdiA-PC (5a , 5.2 mg, 71%). H NMR (CDCl3, 600 MHz): δ
6.88 (d, J ) 15 Hz, 1H), 6.01 (m,1H), 5.24 (m, 1H), 4.15-4.25
(4H), 4.14 (m, 1H), 4.07 (m, 1H), 3.94 (m, 1H), 3.76 (m, 2H),
3.29 (s, 9H), 2.20-2.50 (m, 4H), 1.77 (m, 1H), 1.0.67 (m, 1H),
1.56 (m, 4 H),1.1-1.3 (24 H), 0.86 (t, J ) 6 Hz, 3H). HRMS
(FAB): m/z calcd for C32H61NO11P+ (MH+) 666.39816, found
666.39934.
1-P alm itoyl-2-(9-oxo-12-oxododec-10-en oyl)-sn -glycer o-
3-p h osp h a tid ylch olin e (KODA-P C, 3b). NBS (16 mg, 0.09
mmol) and pyridine (10 mL, 0.12 mmol) were sequentially
added to a solution of furyl phosphatidylcholine 13b (42 mg,
0.06 mmol) in THF/acetone/water (5/4/2) at -20 °C. The
resulting mixture was stirred for 1 h at this temperature and
then kept at room temperature for 5 h. The solvent was then
removed quickly by rotary evaporation, and the residue was
chromatographed on a silica gel column (CHCl3/MeOH/H2O
) 16/9/1) affording a mixture (30 mg) that contained about
80% KODA-P C (3b) as determined by reversed-phase HPLC
analysis described elswhere.7 A second flash chromatography
was necessary to obtain pure KODA-P C (3b, 20 mg, 50%).
1H NMR (CDCl3, 600 MHz): δ 9.77 (d, J ) 7.8 Hz, 1H), 6.87
(d, J ) 16.2 Hz, 1H), 6.76 (dd, J ) 16.2, 7.8, 1H), 5.18 (m,
1H), 4.37 (m, 1H), 4.30 (bm, 2H), 4.10 (dd, J ) 11.4, 7.2, 1H),
3.92 (m, 2H), 3.80 (bm, 2H), 3.35 (bs, 9H), 2.68 (t, J ) 7.2 Hz,
2H), 2.2-2.4 (4H), 1.5-1.7 (6H), 1.1-1.4 (30H), 0.86 (t, J )
6.9 Hz, 3H). HRMS (FAB): m/z 704.4502 (MH+) calcd for
1-P a lm itoyl-2-(9-h yd r oxy-11-ca r boxyu n d ec-10-en oyl)-
sn -glycer o-3-p h osp h a tid ylch olin e (HDd iA-P C, 5b). To a
magnetically stirred solution of HODA-PC (15.3 mg, 0.022
mmol) in t-BuOH-H2O (5:1, v/v, 0.3 mL) was added solution
containing NaH2PO4 (4.5 mg, 0.033 mmol), 2-methyl-2-butene
(65 µL, 0.13 mmol, 2 M solution in THF), and NaClO2 (6 mg,
0.066 mmol) in t-BuOH-H2O (5:1, v/v, 0.3 mL). The resulting
mixture was stirred for 2 h at room temperature under Argon.
The solvent was then removed by rotary evaporation. The
residue was extracted with 4:1 CHCl3-MeOH. The crude
product was purified by flash chromatography on a silica gel
column (CHCl3/MeOH/H2O, 11:9:1; TLC, Rf ) 0.26) to give
1
HDdiA-PC (5b, 11 mg, 70%). H NMR (CDCl3, 600 MHz): δ
6.86 (d, J ) 7.2 Hz, 1H), 6.01 (d, J ) 7.2 Hz, 1H), 5.20 (m,
1H), 4.31 (3H), 4.22 (m, 1H), 4.121 (m, 1H), 3.96 (m, 2H), 3.73
(m, 2H), 3.28 (s, 9H), 2.1-2.3 (4H), 1.55 (4H), 1.4-1.6 (6H),
1.1-1.3 (32H), 0.86 (t, J ) 6 Hz, 3H). HRMS (FAB): m/z calcd
for C36H69NO11P+ (MH+) 722.46077, found 722.46139.
Meth yl 9-Oxon on a n oa te (14). With stirring below -65
°C, ozone was bubbled through a solution of methyl 9Z-
octadecenoate (10 g, 0.0338 mmol, 1.0 equiv) in dry methanol
(55 mL) that had been flushed with N2. After 3.5 h of
continuous bubbling, the reaction was stopped after the total
consumption of methyl 9Z-octadecenoate as indicated by the
appearance of light blue color in the solution. The reaction
mixture was flushed with N2 again. Then triphenylphosphine
(9.2 g, 0.0350 mmol, 1.04 equiv) was added. The resulting
reaction mixture was allowed to warm to -20 °C over 2 h and
then was left overnight at room temperature. The solvent was
removed under reduced pressure, and the crude product was
distilled under reduced pressure (105-108 °C, 1.0 mmHg) to
provide the desired methyl 9-oxononanoate (14, 4.0 g, 64%).
1H NMR (CDCl3, 200 MHz): δ 9.78 (s, 1H), 3.78 (s, 3H), 2.42
(t, 2H, J ) 8.2 Hz), 2.30 (t, 2H, J ) 8.2 Hz), 1.55-1.68 (4H),
1.25-1.38 (6H). This spectrum agrees with that reported
previously.32
C
36H67NO10P, found 704.4502.
1-P alm itoyl-2-(7-car boxy-5-oxoh ept-6-en oyl)-sn -glycer o-
3-p h osp h a tid ylch olin e (KOd iA-P C, 4a ). To a magnetically
stirred solution of KOOA-PC (3a ) (5.3 mg, 0.008 mmol) in
t-BuOH-H2O (5:1, v/v, 0.3 mL) were added NaH2PO4 (1.66
mg, 0.012 mmol), 2-methyl-2-butene (40 µL, 0.085 mmol, 2 M
solution in THF), and NaClO2 (2.2 mg, 0.024 mmol). The
resulting mixture was stirred for 2 h at room temperature
under Ar. The solvent was removed. The residue was extracted
with 4:1 CHCl3/MeOH. The crude product was purified by flash
chromatography on a silica gel column (CHCl3/MeOH/H2O, 15:
1
9:1; TLC, Rf ) 0.23) to give KOOA-acid-PC (3.4 mg, 64%). H
NMR (CD3OD, 600 MHz): δ 6.87 (d, J ) 14.4 Hz, 1H), 6.74
(d, J ) 14.4 Hz, 1H), 5.23 (m, 1H), 4.38 (dd, J 1 ) 12.3 Hz, J 2
) 3 Hz1H), 4.27 (m, 2H), 4.16 (dd, J 1 ) 12, J 2 ) 6.6, 1H), 4.00
(m, 2H), 3.64 (m, 2H), 3.22 (s, 9H), 2.77 (2H), 2.39 (t, J ) 6.6
Hz, 2H), 2.30 (t, J ) 7.2 Hz, 2H), 1.91 (m, 2H), 1.57 (m, 2 H),
1.3-1.2 (24 H), 0.88 (t, J ) 7.2 Hz, 3H). HRMS (MALDI-
TOF): m/z calcd for C32H61NO11P+ (MH+) 664.3826, found
664.3914.
Meth yl 9,9-Dim eth oxyn on a n oa te (15). To a magnetically
stirred solution containing ammonium nitrate (38 mg, 0.1
mmol) in dry methanol (10 mL) were added trimethyl ortho-
formate (2.00 g, 19.0 mmol, 4 equiv) and methyl 9-oxo-
nonanoate (14, 883 mg, 4.75 mmol, 1.0 equiv). The reaction
mixture was stirred at room temperature and monitored by
TLC. After being stirred for 36 h, the reaction was stopped
and solvent was removed completely by rotary evaporation.
The residue was triturated with diethyl ether (30 mL). The
ether solution was filtered through Celite to remove am-
monium nitrate. The filtrate was again concentrated under
reduced pressure. The crude product was subjected to flash
chromatography on silica gel with 25% ethyl acetate in
hexanes (Rf ) 0.37) to afford 15 (926 mg, 84%). 1H NMR
(CDCl3, 200 MHz): δ 4.35 (t, 1H, J ) 6.8 Hz), 3.66 (s, 3H),
3.31 (s, 6H), 2.30 (t, 2H, J ) 8.2 Hz), 1.55-1.68 (4H), 1.28-
1.30 (8H). This spectrum agrees with that reported previ-
ously.36
1-P a lm it oyl-2-(11-ca r b oxy-9-oxou n d ec-10-en oyl)-sn -
glycer o-3-p h osp h a tid ylch olin e (KDd iA-P C, 4b). To a mag-
netically stirred solution of KODA-PC (3b) (10 mg, 0.014
mmol) in t-BuOH-H2O (5:1, v/v, 0.6 mL) was added NaH2-
PO4 (2.8 mg, 0.021 mmol), 2-methyl-2-butene (80 µL, 0.16
mmol, 2 M solution in THF), and NaClO2 (3.8 mg, 0.042 mmol).
The resulting mixture was stirred for 2 h at room temperature
under Ar. The solvent was removed. The residue was extracted
with 4:1 CHCl3/MeOH. The crude product was purified by flash
chromatography on a silica gel column (CHCl3/MeOH/H2O, 11:
1
9:1; TLC, Rf ) 0.29) to give KODA-acid-PC (6.2 mg, 62%). H
NMR (CD3OD, 600 MHz): δ 6.81 (d, J ) 15 Hz, 1H), 6.75 (d,
J ) 15 Hz, 1H), 5.22 (m, 1H), 4.28 (dd, J 1 ) 12 Hz, J 2 ) 3 Hz,
1H), 4.28 (m, 2H), 4.14 (dd, J 1 ) 12 Hz, J 2 ) 7.2 Hz, 1H), 3.99
(m, 2H), 3.64 (m, 2H), 3.22 (s, 9H), 2.65 (t, J ) 7.2 Hz, 2H),
2.0.25-2.35 (4H), 1.5-1.7 (6H), 1.32-1.26 (30 H), 0.88 (t, J )
7.2 Hz, 3H). HRMS (MALDI-TOF): m/z calcd for C36H69NO11P+
(MH+) 720.4452, found 720.4699.
9,9-Dim eth oxyn on a n oic Acid (16). Methyl 9,9-dimeth-
oxynonanoate (15, 142 mg, 0.612 mmol, 1.0 equiv) was stirred

3582 J . Org. Chem., Vol. 67, No. 11, 2002
Sun et al.
with a solution of sodium hydroxide (122.4 mg, 3.06 mmol, 5.0
equiv) in water/methanol/tetrahydrofuran (2:5:3, v/v/v, 3.06
mL) at room temperature. The reaction was monitored by TLC
for the disappearance of the starting ester. After being stirred
for 1.5 h, the reaction was stopped, the reaction mixture was
acidified to pH 3 with ice-cold 2 N HCl, and then the aqueous
layer was extracted with ethyl acetate (4 × 15 mL). The
combined organic extracts were washed once with brine (10
mL), dried over MgSO4, and filtered, and solvent was removed
under reduced pressure to provide pure 9,9-dimethoxynonanoic
acid (16, 127 mg, 95% yield). The acid was used immediately
for the next step without further purification. 1H NMR
(acetone-d6, 200 MHz): δ 4.38 (t, 1H, J ) 7.5 Hz), 3.25 (s, 6H),
2.28 (t, 2H, J ) 8.8 Hz), 1.45-1.70 (4H), 1.25-1.45 (8H). 13C
(aceton-d6, 75 MHz): δ 174.8, 105.3, 52.8, 34.3, 33.4, 30.2, 30.1,
stirred for 2 days. The solvent was then removed by rotary
evaporation. The residue was flash chromatographed on a
silica gel column (CHCl3/MeOH/H2O ) 16:9:1), producing
A-P C (2, 50 mg, 74%). 1H NMR (CDCl3, 300 MHz): δ 5.20 (m,
1H), 4.30-4.37 (3H), 4.13 (dd, J ) 11.2, 7.0, 1H), 3.96 (m, 2H),
3.79 (bm, 2H); 3.33 (bs, 9H), 2.22-2.29 (6H), 1.5-1.7 (6H),
1.2-1.4 (32H), 0.86 (t, J ) 6.8 Hz, 3H). HRMS (FAB): m/z
666.4346 (MH+) calcd for C33H65NO10P, found 666.4336.
cis-4-(1,1,2,2-Tet r a m et h yl-1-sila p r op oxy)b u t -2-en -1-
ol (21). To a solution of but-2-ene-1,4-diol (5 g, 56.7 mmol),
DMAP (350 mg, 1.4 mmol), and Et3N (4.8 mL, 34 mmol) in
CH2Cl2 (150 mL) was added TBDMSCl (4.2 g, 27.8 mmol) in
CH2Cl2 (10 mL) over 4 h with a syringe pump at room
temperature. The reaction mixture was stirred under N2
overnight, washed with water, aqueous NH4Cl, and brine, and
dried over MgSO4. Flash chromatography on a silica gel
column (25% ethyl acetate in hexanes, Rf ) 0.3) afforded the
silyl ether 21 (4 g, 70%). 1H NMR (CDCl3, 300 MHz): δ 5.55-
5.75 (2 H), 4.21 (m, 2 H), 4.14 (m, 2 H), 2.45 (br, 1 H), 0.86 (s,
9 H), 0.04 (s, 6 H). 13C NMR (CDCl3, 75 MHz, APT): δ 131.20
(CH), 130.12 (CH), 59.57 (CH2), 58.70 (CH2), 25.91 (CH3), 18.33
(C), -5.32 (CH3). HRMS (EI): m/z calcd for C10H22O2Si (M+)
202.1324, found 202.1389; calcd for C10H23O2Si (MH+) 203.1468,
found 203.1464; calcd for C10H21OSi (M+ - OH) 185.1362,
found 185.1329.
29.9, 25.7, 25.4. HRMS (20 eV): m/z calcd for C10H19O3 (M+
OCH3) 187.1334, m/z found 187.1365.
-
1-P a lm it oyl-2-(9,9-d im et h oxyn on a n oyl)-sn -glycer o-3-
p h osp h a tid ylch olin e (17). Esterification of 2-lysophosphati-
dylcholine with 9,9-dimethoxynonaoic acid (16) was accom-
plished by a general method reported previously.4 Traces of
moisture were removed from a mixture of acid 9 (219 mg, 1.00
mmol, 2.9 equiv) and 1-palmitoyl-2-lyso-sn-glycero-3-phos-
phatidylcholine (169 mg, 0.34 mmol, 1.0 equiv) by azeotropic
distillation with toluene (3 × 10 mL) under reduced pressure
at room temperature, and the mixture was attached to a high
vacuum pump (0.1 mmHg) and evacuated through a dry ice-
acetone cooled trap for 5 h. Anhydrous CHCl3 (20 mL) freshly
distilled from P2O5, dicyclohexylcarbodiimide (207 mg, 1.0
mmol, 3.0 equiv), and N,N-dimethylaminopyridine (134 mg,
1.1 mmol, 3.3 equiv) were added. Then the flask was flushed
with nitrogen and protected from light. The reaction mixture
was stirred at room temperature and was monitored by TLC
for the disappearance of lysophosphatidylcholine. The reaction
was stopped after stirring for 48 h, and the solvent was
removed completely under reduced pressure. The resulting
residue was flash chromatographed on silica gel with CHCl3/
MeOH/H2O (40:50:10, v/v/v, Rf ) 0.35) as eluant to afford 17
4-Br om o-1-(1,1,2,2-t et r a m et h yl-1-sila p r op oxy)b u t -2-
en e (22). To a solution of the alcohol 21 (3.2 g, 15.8 mmol) in
CH2Cl2 (200 mL) at 0 °C were added tetrabromomethane (5.8
g, 17.5 mmol) and bis(1,2-diphenylphosphino)ethane (DIPHOS)
(7.5 g, 18.8 mmol). The resulting mixture was stirred at room
temperature for 45 min. The solvent was removed by rotary
evaporation. The residue was extracted with hexane. The
organic extracts were concentrated and purified by flash
chromatography on a silica gel column (2% ethyl acetate in
hexanes, Rf ) 0.3) to afford the desired bromide 22 (7.8 g, E/Z
1
) 1:4, 92%). H NMR (CDCl3, 300 MHz): δ 5.55-5.84 (2 H),
4.32 (d, J ) 5.4 Hz, 2 H), 4.03 (d, J ) 7.7 Hz, 2 H), 0.88 (s, 9
H), 0.06 (s, 6 H). 13C (CDCl3, 75 MHz, APT): δ 134.52 (CH),
125.90 (CH), 59.03 (CH2), 26.86 (CH2), 26.04 (CH3), 18.33 (C),
-5.25 (CH3). HRMS (EI): m/z calcd for C10H21BrOSi (M+)
264.0545, found 264.0546; calcd for C9H18BrOSi (M+ - Me)
249.0310, found 249.0329.
1
(225 mg, 95% based on lyso-PC). H NMR (CDCl3, 300 MHz):
δ 5.18-5.24 (m, 1H), 4.33-4.40 (4H), 4.10-4.17 (dd, 1H, J )
4.2 Hz, 7.4 Hz), 3.91-3.95 (m, 2H), 3.63-3.67 (m, 2H), 3.30
(s, 9H), 3.23 (s, 6H), 2.18-2.35 (4H), 1.51-1.59 (6H), 1.28-
1.38 (8H), 1.22-1.28 (24H), 0.88 (t, 3H, J ) 8.0 Hz). HRMS
(20 eV): m/z calcd for C34H67NO9P (M+ - OCH3) 664.4553, m/z
found 664.4560.
Diet h oxyp h osp h in o(4-(1,1,2,2-t et r a m et h yl-1-sila p r o-
p oxy)bu t-2-en yl)-1-on e (E/Z ) 4:1) (23). Meth od A. A
mixture of the bromide 22 (1.6 g, 6.0 mmol) and (EtO)3P (1.53
mL, 9 mmol) was heated to 130-135 °C for 6 h. The low boiling
point fraction was removed by distillation under reduced
pressure (50-60 °C, 15 mmHg). The residue was purified by
flash chromatography on a silica gel column to give the desired
compound 23 (1.6 g, 84%). TLC: Rf ) 0.26 (2% methanol in
CH2Cl2). 1H NMR (CDCl3, 300 MHz): δ 6.67 (m, 1 H), 5.42
(m, 1 H), 4.18 (m, 2 H), 4.03 (qd, J ) 7.4, 7.1 Hz, 4 H), 2.56
(dd, J ) 22.3, 7.9 Hz, 2 H), 1.25 (t, J ) 7.1 Hz, 6 H), 0.83 (s,
9 H), 0.00 (s, 6 H). 13C (CDCl3, 75 MHz, APT): δ 134.17 (d,
J PC ) 9.8 Hz, CH), 118.69 (d, J PC ) 8.6 Hz, CH), 61.91 (d,
J PC ) 4.9 Hz, CH2), 59.34 (d, J PC ) 2.3 Hz, CH2), 26.23 (d,
J PC ) 104.6 Hz), 25.89 (CH3), 18.30 (C), 16.45 (d, J PC ) 4.5
Hz), -5.21 (CH3). HRMS (EI): m/z calcd for C14H32O4PSi
(MH+) 323.1808, found 323.1792; calcd for C13H28O4PSi
(M+ - Me) 307.1494, found 307.1490.
Meth od B. tert-Butyl dimethylsilyl chloride (1 g, 6.6 mmol)
was added to a stirred suspension of CaCO3 (70 mg, 0.7 mmol),
NaI (990 mg, 6.6 mmol), and DMAP (320 mg, 2.6 mmol) in
2,5-dihyrofuran (2,5-DHF, 8 mL). The mixture was refluxed
for 48 h, and then the excess 2,5-DHF was removed with a
rotary evaporator to give a residue that was purified by flash
chromatography on a silica gel column (1.5% ethyl acetate in
hexanes) to afford 4-iod o-1-(1,1,2,2-t et r a m et h yl-1-sila -
p r op oxy)bu t-2-en e (25, 1 g, 52%). 1H NMR (CDCl3, 300
MHz): δ 5.9-6.0 (m, 1 H), 5.79 (dt, J ) 4.6,J ) 15.8 Hz, 1H)
4.16 (d, J ) 4.6 Hz, 2 H), 3.89 (d, J ) 7.8 Hz, 2 H), 0.91 (s, 9
H), 0.07 (s, 6 H). 13C (CDCl3, 75 MHz): δ 133.31 (CH), 127.54
(CH), 62.70 (CH2), 26.01 (CH3), 25.90 (CH2), 18.44 (C), 5.38
(CH2), -5.12 (CH3). This iodide was characterized further by
conversion to 23. A mixture of the iodide (400 mg, 1.28 mmol)
1-P a lm itoyl-2-(9-oxon on a n oyl)-sn -glycer o-3-p h osp h a ti-
d ylch olin e (ON-P C, 1). Hydrolysis of 1-palmitoyl-2-(9,9-
dimethoxynonanoyl)-sn-glycero-3-phosphatidylcholine 17 was
catalyzed by an acidic resin.6 Thus, phospholipid acetal 17 (28
mg, 0.040 mmol) was dissolved in acetone-water (5:1, v/v, 6
mL) and stirred magnetically with Amberlyst-15 resin (15 mg).
The reaction was monitored by TLC for the total disappearance
of acetal. After the mixture was stirred at room temperature
for 6 h, the reaction was stopped, the mixture was filtered,
and the solvent was removed under reduced pressure. The
crude product was flash chromatographed on a silica gel
column with CHCl3/MeOH/H2O (40:50:10, v/v/v, Rf ) 0.29) as
eluant to yield the desired 1-palmitoyl-2-(9-oxononanoyl)-sn-
glycero-3-phosphatidylcholine (26 mg, 92%). 1H NMR (CDCl3,
600 MHz): δ 9.76 (s, 1H), 5.18-5.22 (1H), 4.2-4.4 (3H), 4.0-
4.2 (1H), 3.77-3.93 (m, 2H), 3.62-3.72 (3H), 3.34 (s, 9H),
2.40-2.45 (t, 2H, J ) 8.2 Hz), 2.22-2.33 (4H), 1.48-1.57 (6H),
1.18-1.32 (30H), 0.88 (t, 3H, J ) 7.6 Hz). HRMS (20 eV): m/z
calcd for C33H64NO9P (M+) 649.4318, m/z found 649.4325.
1-P a lm it oyl-2-a zeleyl-sn -glycer o-3-p h osp h a t id ylch o-
lin e (A-P C, 2). Azeleic acid anhydride was prepared from
azeleic acid according to the reported procedure.16 The anhy-
dride was recrystallized twice from dry benzene. The anhy-
dride (102 mg, 0.6 mmol) and DMAP (12 mg, 0.1 mmol) were
added under argon to a solution of 2-lysoPC (50 mg, 0.1 mmol)
in dry CHCl3 freshly distilled from P2O5. The mixture was
(36) Sabedio, J . L.; Ackman, R. G. Can. J . Chem. 1978, 56, 2480-
2485.

Novel Bioactive Phospholipids
J . Org. Chem., Vol. 67, No. 11, 2002 3583
and (EtO)3P (0.5 mL, 3 mmol) was heated to 120 °C for 6 h.
The low boiling point fraction was removed by distillation
under reduced pressure (50-60 °C, 15 mmHg). The residue
was purified by flash chromatography on a silica gel column
(2% methanol in CH2Cl2, TLC Rf ) 0.26) to give the desired
product was hydrolyzed37 and purified via flash chromatog-
raphy on a silica gel column (10% ethyl acetate in hexanes,
TLC, Rf ) 0.25, with a depth of 8-9 in. of silica gel, instead of
the 5-6 in. recommended,38 to improve the hydrolysis of the
imines) to afford methyl 13-oxotrideca-9,11-dienoate (27, 70
1
1
compound 15 (E/Z ) 4:1, 380 mg, 90%). H NMR (CDCl3, 300
mg, 70%). H NMR (CDCl3, 300 MHz): δ 9.51 (d, J ) 8 Hz, 1
MHz): δ 5.77-5.66 (2H), 4.17-4.06 (6 H), 2.60 (dd, J ) 21.3,
6.9 Hz, 2 H), 1.32 (t, J ) 7.1 Hz, 6 H), 0.81 (s, 9 H), 0.07 (s, 6
H). 13C (CDCl3, 75 MHz): δ 134.6 (d, J PC ) 10.7 Hz), 119.4 (d,
J PC ) 7.9 Hz), 63.4 (d, J PC ) 1.9 Hz), 61.9 (d, J PC ) 5.0 Hz),
30.2 (d, J PC ) 104.2), 26.0, 18.4 (C), 16.5 (d, J PC ) 4.5 Hz),
-5.2 (CH3). HRMS (EI): m/z calcd for C14H32O4PSi (MH+)
323.1808, found 323.1792; calcd for C13H28O4PSi (M+ - Me)
307.1494, found 307.1495.
Dieth oxy(4-h yd r oxybu t-2-en yl)p h osp h in o-1-on e (E/Z )
4:1) (24). To the solution of TBDMS ether 15 (100 mg, 0.31
mmol) in Me2CO (2 mL) was added 2 N H2SO4 (1 mL). The
resulting mixture was stirred for 3 h at room temperature and
then extracted with CH2Cl2 (3 × 5 mL). The solvent was
removed, and the residue was purified by flash chromatogra-
phy on a silica gel column with 3% methanol in CH2Cl2 (TLC,
Rf ) 0.25) to afford phosphoryl alcohol 24 (60 mg, 93%). 1H
NMR (CDCl3, 300 MHz): δ 5.75 (m, 1 H), 5.45 (m, 1 H), 3.8-
4.0 (4 H), 2.52 (dd, J ) 22.6, 8.1 Hz, 2 H), 1.15 (t, J ) 7.1 Hz,
6 H). 13C NMR (CDCl3, 75 MHz): δ 134.26 (d, J PC ) 9.9 Hz),
119.66 (d, J PC ) 8.9 Hz), 62.28 (d, J PC ) 5.1 Hz), 57.71 (d, J PC
) 2.2 Hz), 25.54 (d, J PC ) 103.6 Hz), 16.34 (d, J PC ) 4.4 Hz).
HRMS (EI) m/z calcd for C8H17O4P (M+) 208.0864, found
208.0873; calcd for C8H16O3P (M+ - OH) 191.0837, found
191.0842.
4-(Dieth oxyp h osp h or yl)-2E-bu ten a l (20E). To a solution
of alcohol 24 (430 mg, 2.06 mmol) in acetone (10 mL) was
added dropwise CrO3 in 2 N H2SO4 (210 mg, 2.07 mmol, 2.1
mL of 100 mg/mL CrO3 solution) at 0 °C. The resulting mixture
was stirred for 15 min at 0 °C, and another 15 min at room
temperature, then quenched by addition of 1 mL of 2-propanol.
After the mixture was stirred for another 10-15 min, solid
NaHCO3 (1 g) was added, and the mixture was stirred for a
few minutes and then filtered. The filtrate was refluxed (60
°C) for 30-60 min for isomerization (before isomerization, E/Z
) 4:1). After the mixture was cooled to room temperature,
acetone was removed with a rotary evaporator. The aqueous
solution was extracted with CH2Cl2 (3 × 10 mL). The organic
extract was washed with water and brine, dried (MgSO4), and
concentrated. TLC (4% MeOH in CH2Cl2, Rf ) 0.27) and 1H
NMR showed that the product (380 mg, 90%) was suitable for
the next reaction without further purification. 1H NMR (CDCl3,
300 MHz): δ 9.49 (d, J ) 7.8 Hz, 1 H), 6.75 (ddd, J ) 15.5,
15.4, 7.9 Hz, 1 H), 6.18 (m, 1 H), 4.0-4.2 (4 H), 2.84 (dd, J )
22.5, 7.7 Hz, 2 H), 1.28 (t, J ) 7.1 Hz, 6 H). The NMR spectrum
is consistent with that reported previously.26
H), 7.05 (m, br dd, J ) 15.3, 9.8 Hz, 1 H), 6.25 (m, 2 H), 6.04
(dd, J ) 15.3, 8.0 Hz, 1 H), 3.63 (s, 3H), 2.27 (t, J ) 7.3 Hz, 2
H), 2.22 (m, 2 H), 1.5-1.7 (2 H), 1.3-1.5 (2 H), 1.15-1.35 (6
H). HRMS (EI): m/z calcd for C14H22O3 (M+) 238.1569, found
238.1573; calcd for C14H23O3 (MH+) 239.1649, found 1239.1654.
Meth yl 13,13-Dim eth oxytr id eca -9E,11E-d ien oa te (28).
K-10 montmorillonite clay (2 g) was mixed with trimethyl
orthoformate (1.5 mL) and methanol (1.5 mL). The resulting
mixture was stirred for a few minutes and then filtred. The
wet filter cake (Taylor reagent for acetalization15) was used
directly without any further treatment. Methyl 13-oxotrideca-
9E,11E-dienoate (27, 57 mg, 0.24 mmol) was stirred with a
suspension of the K-10 montmorillonite/trimethyl orthoformate
reagent (200 mg) in dichloromethane (1 mL) at room temper-
ature for 2 h, with monitoring by TLC until complete conver-
sion. The mixture was filtered through a Celite 521 bed,
followed by washing the filtrate with saturated NaHCO3
solution, water, and brine and drying over MgSO4. The solvent
was removed by rotary evaporation. The last traces of solvent
were transferred into a dry ice-acetone cooled trap under high
vacuum (0.1 mmHg) for 1 h to afford the desired product 28
(60 mg, 88%). Because the compound partially decomposed on
the silica gel column, the product was used immediately for
next step without further purification (>95% pure by NMR,
TLC 10% ethyl acetate in hexanes, Rf ) 0.17). 1H NMR (CDCl3,
300 MHz): δ 6.26 (ddd, J ) 15.4, 10.3, 1.0 Hz, 1 H), 5.99 (bdd,
J ) 15.0, 10.3 Hz, 1 H), 5.70 (dt, J ) 14.8, 8.3 Hz, 1 H), 5.45
(dd, J ) 15.4, 5.2 Hz, 1 H), 4.76 (d, J ) 5.2 Hz, 1 H), 3.61 (s,
3 H), 3.26 (s, 6 H), 2.25 (t, J ) 7.5 Hz, 2 H), 2.03 (td J ) 6.9,
6.5 Hz, 2 H), 1.45-1.65 (2 H), 1.10-1.40 (8 H). 13C NMR
(CDCl3, 75 MHz, APT): δ 174.29 (C), 137.13 (CH), 134.13 (CH),
129.08 (CH), 126.44 (CH), 102.87 (CH), 52.59 (CH3), 51.46
(CH3), 34.07 (CH2), 32.61 (CH2), 32.44 (CH2), 29.07 (CH2), 24.92
(CH2), 24.53 (CH2). HRMS (EI): m/z calcd for C16H28O4 (M+)
284.1987, found 284.1993; calcd for
C
16H27O4 (M+ - H)
283.1907, found 283.1907; calcd for C15H25O3 (M+ - HOMe)
252.1724, found 252.1734.
13-Oxotr id eca -9E,11E-d ien oic Acid (OTDEA, 18). Meth-
yl 13,13-dimethoxytrideca-9E,11E-dienoate (28, 50 mg, 0.176
mmol) was stirred with a solution of sodium hydroxide (35 mg,
0.875 mmol) in water/methanol/THF (2:5:3, v/v/v, 1 mL) at
room temperature. The reaction was monitored by TLC until
complete disappearance of the starting material. After being
stirred for 2.5 h, the reaction mixture was acidified to pH 3
with ice-cold 1 N HCl. The resulting acidic solution was stirred
for 30 min under a N2 atmosphere at room temperature and
then extracted with ethyl acetate (3 × 5 mL). The organic
extract was washed with brine, dried over MgSO4, and
concentrated by rotary evaporation. Flash chromatography on
a silica gel column afforded the hydrolyzed dienoic acid
OTDEA (18, 32 mg, 82%), TLC (ethyl acetate/hexanes/acetic
(5-Aza-5-cycloh exylpen ta-2,4-dien yl)dieth oxyph osph in -
1-on e (19). To a solution of the phosphoryl aldehyde 20E (160
mg, 0.78 mmol) in dry THF (1.5 mL) was added dropwise
cyclohexylamine (77.5 mg, 0.78 mmol) at room temperature
under argon atmosphere. After 1 h, freshly activated 4 Å
molecular sieves (ca. 0.1 g/0.1 g of the aldehyde) were added,
and the reaction mixture was stirred gently overnight to
1
acid, 45:55:0.5, v/v/v, Rf ) 0.35). H NMR (CDCl3, 300 MHz):
1
provide intermediate 19 in situ. The H NMR spectrum of 11
δ 9.48 (d, J ) 8.0 Hz, 1 H), 7.05 (dd, J ) 15.4, 9.9 Hz, 1 H),
6.20-6.30 (2 H), 6.04 (dd, J ) 15.4, 8.0 Hz, 1 H), 2.30 (t, J )
7.4 Hz, 2 H), 2.17 (td, J ) 6.8, 6.6 Hz, 2 H), 1.55-1.65 (2 H),
1.15-1.55 (8 H). 13C NMR (CDCl3, 75 MHz): δ 194.18 (CHO),
179.98 (COOH), 153.06, 147.37, 130.05, 128.76, 34.03, 33.18,
29.02, 28.96, 28.48, 24.62. HRMS (EI): m/z calcd for C13H20O3
(M+) 224.1412, found 224.1413. The NMR spectrum is consis-
tent with that reported (isolated from lipid oxidation).22,34
is in agreement with that reported previously.26
Meth yl 13-Oxotr id eca -9E,11E-d ien oa te (27). The result-
ing bright orange solution of imine 19 was added dropwise to
a solution of LDA (0.66 mmol, 380 µL of 2 M solution in
hexane, 0.97 equiv) at -78 °C under an argon atmosphere via
a airtight syringe. The color of the solution changed instan-
taneously to deep red. After the mixture was stirred for 1 h at
-78 °C, methyl 9-oxononanoate 14 (115 mg, 0.62 mmol) in dry
THF (1 mL) was added. The resulting mixture was stirred at
-78 °C for 1 h and then warmed to 0 °C for 2 h and room
temperature for another 1 h. Then water (3 mL) was added,
and the mixture was stirred for a few minutes and then
extracted with ethyl ether (3 × 5 mL). The organic extract was
dried over MgSO4. Rotary evaporation of the solvent provided
the crude cyclohexyl imine as an orange-red oil. The crude
13,13-Dim eth oxytr ideca-9E,11E-dien oic Acid (29). Meth-
yl 13,13-dimethoxytrideca-9E,11E-dienoate (28, 30 mg,
(37) McDougal, P. G.; Rico, J . G.; Oh, Y. I.; Condon, B. D. J . Org.
Chem. 1986, 51, 3388-90.
(38) Katsuki, T.; Lee, A. W. M.; Ma, P.; Martin, V. S.; Masamune,
S. M.; Sharpless, K. B.; Tuddenham, D.; Walker, F. J . J . Org. Chem.
1982, 47, 1373-8.

3584 J . Org. Chem., Vol. 67, No. 11, 2002
Sun et al.
0.105 mmol) was stirred with a solution of sodium hydroxide
(25 mg, 0.625 mmol) in water/methanol/THF (2:5:3, v/v/v, 1
mL) at room temperature. The reaction was monitored by TLC
until complete disappearance of the starting material. After
being stirred for 2.5 h, the reaction mixture was acidified to
pH 4 with ice-cold 0.5 N HCl and then extracted with ethyl
acetate (3 × 5 mL) at 0 °C. The organic extract was washed
with water and brine and then dried over MgSO4. The solvent
was removed by rotary evaporation. The last traces of solvent
were transferred into a dry ice-acetone cooled trap under high
vacuum (0.1 mmHg) for 3 h to give the acetal acid 29 in 80%
yield. This product was used for next reaction without further
purification, TLC (ethyl acetate/hexanes/acetic acid, 45:55:0.1,
P2O5). Dicyclohexylcarbodiimide (DCC, 33 mg, 0.16 mmol) and
N,N-dimethylaminopyridine (DMAP, 7 mg, 0 .06 mmol) were
added. The resulting mixture was stirred for 48 h, washed with
1N HCl (1 mL), and extracted with CHCl3/MeOH (2:1, v/v)
solution (4 × 5 mL). The combined extracts were dried over
MgSO4 and concentrated. The residue was purified by flash
chromatography on silica gel with CHCl3/MeOH/H2O (55:40:
5, v/v/v, Rf ) 0.23) to deliver the dienal phospholipid OTDE-
1
P C (6, 27 mg, 77%). H NMR (CDCl3, 300 MHz): δ 9.51 (d, J
) 8.0 Hz, 1 H), 7.06 (m, 1 H), 6.15-6.35 (2 H), 6.05 (dd, J )
15.4, 8.0 Hz, 1 H), 5.17 (bs, 1 H), 4.25-4.45 (3 H), 4.10 (m, 1
H), 3.94 (m, 2 H), 3.80 (m, 2 H), 3.36 (bs, 9 H), 2.12-2.35 (6
H), 1.5-1.65 (6 H), 1.40-1.50 (2 H), 1.10-1.40 (30 H), 0.85 (t,
J ) 6.9 Hz, 3 H). HRMS (FAB, NaI/mNBA/PEG246): m/z calcd
for C37H68NNaO9P+ (MNa+) 724.4529, found 724.4544.
1
v/v/v, Rf ) 0.3). H NMR (CDCl3, 300 MHz): δ 6.27 (dd, J )
14.5, 10.5 Hz, 1 H), 6.00 (dd, J ) 14.5, 10.2 Hz, 1 H), 5.71 (J
) 15.0, 6.8 Hz, 1 H), 5.46 (dd, J ) 15.0, 5.1 Hz, 1 H), 4.77 (d,
J ) 5.2 Hz, 1 H), 3.27 (s, 6 H), 2.26 (t, J ) 7.5 Hz, 2 H), 2.04
(td, J ) 6.6, 5.1 Hz, 2 H), 1.45-1.65 (2 H), 1.15-1.45 (8 H).
HRMS (EI): m/z calcd for C16H28O4 (M+) 270.1831, found
270.1830.
Ack n ow led gm en t. We thank the National Institute
of General Medical Sciences of the National Institutes
of Health for support of this research by grants HL53315
and GM21249 (to R.G.S.).
Dien a l P h osp h olip id (OTDE-P C, 6). A mixture of the
dienoic acid 29 (24 mg, 0.107 mmol) and 1-palmitoyl-2-lyso-
sn-glycero-3-phosphatidylcholine (25 mg, 0.05 mmol) was dried
by transfer of moisture into a dry ice-acetone-cooled trap
under high vacuum (0.1 mmHg) for 5 h at room temperature
and then dissolved in dry CHCl3 (2 mL, freshly distilled from
Su p p or t in g In for m a t ion Ava ila b le: 1H and 13C NMR
spectra of new compounds. This material is available free of
charge via the Internet at http://pubs.acs.org.
J O0105383