Macrocyclic diacylglycerol-bis-lactones as conformationally constrained analogues of diacylglycerol-lactones. Interactions with protein kinase C

Article abstract of DOI:10.1021/jm0497747

A series of macrocyclic diacylglycerol (DAG)-bis-lactones were investigated as extreme conformationally constrained analogues of DAG-lactones in order to seek more potent protein kinase C (PKC) ligands with higher binding affinities and less lipophilicity

Full text of DOI:10.1021/jm0497747

4000
J . Med. Chem. 2004, 47, 4000-4007
Ma cr ocyclic Dia cylglycer ol-bis-la cton es a s Con for m a tion a lly Con str a in ed
An a logu es of Dia cylglycer ol-la cton es. In ter a ction s w ith P r otein Kin a se C
J i-Hye Kang,† Su Yeon Kim,† J eewoo Lee,*,† Victor E. Marquez,‡ Nancy E. Lewin,§ Larry V. Pearce,§ and
Peter M. Blumberg§
Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Shinlim-Dong,
Kwanak-Ku, Seoul 151-742, Korea, Laboratory of Medicinal Chemistry, Center for Cancer Research, National Cancer Institute,
National Institues of Health, Frederick, Maryland 21701, and Laboratory of Cellular Carcinogenesis and Tumor Promotion,
Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892
Received March 23, 2004
A series of macrocyclic diacylglycerol (DAG)-bis-lactones were investigated as extreme
conformationally constrained analogues of DAG-lactones in order to seek more potent protein
kinase C (PKC) ligands with higher binding affinities and less lipophilicity than previous
compounds. The additional constraint achieved the desired objective as exemplified by the
macrocyclic DAG-bis-lactone 57, which exhibited a 6-fold higher binding affinity for PKCR (Ki
) 6.07 nM) than the corresponding nonmacrocyclic 3-alkylidene DAG-lactone 6. A structure-
activity relationship (SAR) analysis of the macrocyclic DAG-bis-lactones demonstrated a
parabolic relationship between activity and lipophilicity, as well as a predilection for the
Z-alkylidene isomers as the preferred ligands. Molecular docking studies revealed that
macrocyclic DAG-bis-lactone 57 bound to the C1b domain of PKCR exclusively in the sn-1
binding mode in contrast to DAG-lactone 6, which showed both sn-1 and sn-2 binding modes.
It is proposed that the high potency displayed by these macrocyclic DAG-bis-lactones results
from a set of more favorable hydrogen bonding and hydrophobic interactions with PKCR as
well as from a reduced entropy penalty due to conformational restriction.
In tr od u ction
Protein kinase C (PKC) comprises a family of serine/
threonine kinases implicated in growth factor and
G-protein-coupled receptor signaling and plays a key
regulatory role in signal transduction events in response
to specific hormonal, neuronal and growth factor
stimuli.1-3 The intrinsic function of PKC isozymes is
regulated by three mechanisms: (1) phosphorylation,
which primes the enzyme for catalysis, (2) cofactor
binding, which allosterically activates the enzyme, and
(3) interaction with targeting proteins that position PKC
near its regulators and substrates.4 The PKC family can
be divided into three isozyme groups based on the
differences in their structure and substrate require-
ments: conventional (R, âΙ, âΙΙ, and γ), novel (δ, ꢀ, η,
and θ), and atypical (ú and ι/λ) groups.4,5 Conventional
and novel isozymes have twin diacylglycerol responsive
C1 regions and become activated as a result of the
association of the cytosolic enzyme with membranes
containing acid phospholipids.6 The physiological func-
F igu r e 1. DAG-lactones as PKC ligands.
tion of individual PKC isozymes has been identified
the presence of phospholipid. Phorbol esters also bind
to the DAG-binding site of the enzyme in a competitive
manner and function as potent and metabolically stable
DAG surrogates. The binding affinities of phorbol esters
are 3-4 orders of magnitude greater than those of
DAGs,8 and their higher potencies are anticipated to be
derived from a conformationally rigid orientation of
hydrophilic pharmacophores unlike the less constrained
orientation resulting from the flexible glycerol of DAG.
Over the past few years, we have explored conforma-
tionally constrained DAG analogues, so-called DAG-
lactones, to bridge the affinity gap between phorbol
using pharmacological approaches by PKC activators
and inhibitors that display varying degrees of selectivity
for the isozymes.7
Diacylglycerol (DAG) is an endogenous activator that
binds to the Cl domain(s) of conventional and novel
PKCs, where it allosterically activates the enzyme in
* To whom correspondence should be addressed. Phone: 82-2-880-
7846. Fax: 82-2-888-0649. E-mail: jeewoo@snu.ac.kr.
† Seoul National University.
‡ Laboratory of Medicinal Chemistry, National Cancer Institute.
§ Laboratory of Cellular Carcinogenesis and Tumor Promotion,
National Cancer Institute.
10.1021/jm0497747 CCC: $27.50 © 2004 American Chemical Society
Published on Web 06/29/2004

DAG-bis-lactones
J ournal of Medicinal Chemistry, 2004, Vol. 47, No. 16 4001
Sch em e 1. Syntheses of Aldehydesa
a
Reagents and conditions: (a) TrCl, pyridine, 60-70%; (b) PCC,
4 Å molecular sieves, CH2Cl2, 70-80%.
Sch em e 2. Syntheses of DAG-bis-macrolactonesa
F igu r e 2. Conformational constraint of DAG-lactones.
esters and DAGs.9,10 Pharmacophore-guided approaches
following extensive SAR studies have led to a reduction
in the potency gap between phorbol esters and DAGs
by approximately 2 orders of magnitude (Figure 1). The
first increase in binding affinity from DAG, e.g., glycerol-
1-myristate-2-acetate (1, Ki ≈ 1 µM), was achieved by
cyclization to the 5-tetradecanoyl DAG-lactone (2, Ki )
138 nM).11 The second improvement in binding affinity
was accomplished by shifting the hydrophobic alkyl
chain from the 5-acyl to the 3-alkylidene position,
resulting in the 3-tetradecylidene lactone (3, Ki ) 35
nM).11,12 These steps provided ca. 7- and 4-fold increases
in binding affinity, respectively. Recently, more sophis-
ticated receptor-guided approaches using the crystal
coordinates of the C1b domain of PKCδ in complex with
phorbol 13-acetate led to the design of highly branched
alkyl chains capable of interacting with a cluster of
conserved hydrophobic amino acids in the space between
the two â-sheets of the C1 domain.13 Eventually, these
new DAG-lactones bearing branched alkyl chains were
able to achieve low nanomolar binding affinities for
PKCR. For example, DAG-lactone 4 (Ki ) 2.9 nM) has
12-fold higher binding affinity than 3, a linear DAG-
lactone with similar lipophilicity.14,15
a
Reagents and conditions: (a) (i) LiHMDS, THF, -78 °C; (ii)
RCHO (13-16); (b) (i) MsCl, NEt3, CH2Cl2; (ii) DBU, 45-52% for
two steps; (c) HCO2H, ether, 100%; (d) PDC, DMF, 80-88%; (e)
CAN, CH3CN/H2O, 75-82%; (f) DMAP, DMAP/HCl, DCC, CH2Cl2,
60-70%; (g) BCl3, CH2Cl2, 80-92%.
candidates. Another advantage from the second lacton-
ization is the reduction in lipophilicity resulting from
cyclization, something known as the “cyclic ester cor-
rection”, which can reduce the log P value by as much
as 1.5 units.16 This reduction is equivalent to the effect
of excising three carbons (ca. 0.5 unit each) from the
fatty chain. Therefore, we envisaged that the confor-
mational restriction of the acyclic ester (5-acyl group)
would result in both an increase in binding affinity, by
reducing the entropy penalty, and a lowering of lipo-
philicity.
The high potency of DAG-lactones is basically derived
from the loss of the entropic penalty of the flexible DAG
glycerol backbone upon cyclization. Therefore, we envis-
aged that an additional conformational restriction of the
remaining acyclic ester, the 5-acyl group, might likewise
produce an entropic advantage in binding to the enzyme.
One approach to achieve further conformational restric-
tion was to link the two terminal alkyl ends of the 5-acyl
and 3-alkylidene groups of the DAG-lactones to generate
a macrocyclic ring. This would restrict the conforma-
tional mobility of the alkyl chain by allowing the ester
to adopt the preferred s-trans configuration for ring
sizes greater than 10. Following this approach, DAG-
lactones 5-8 would generate the corresponding macro-
cyclic DAG-bis-lactones as depicted in Figure 2. These
bis-lactones would contain a [x.2.1] bicyclic skeleton with
x ) 18 (for n ) 12) in the case of macrocyclic DAG-bis-
lactones generated from DAG-lactones 5 or 6.
In this study, a series of macrocyclic DAG-bis-lactones
having a [x.2.1] bicyclic skeleton were synthesized and
evaluated as PKCR ligands. Their binding mode with
the enzyme was also investigated by molecular model-
ing.
Ch em istr y
Aldehydes 13-16 used for the condensation with
γ-lactone (17) were prepared starting from the corre-
sponding commercially available diols after two con-
secutive steps involving monotritylation and oxidation
as shown in Scheme 1. The synthesis of the macrocyclic
DAG-bis-lactones (53-59) is illustrated in Scheme 2.
5-Benzyloxymethyl-5-(4-methoxyphenoxy)methyl-γ-lac-
tone (17), synthesized according to the previously
published procedure,17 was condensed with the alde-
hydes (13-16), and the intermediate â-hydroxylactones
obtained were converted (by elimination) into 3-alkyl-
idene γ-lactones (18-24) as mixtures of E/Z isomers.
In the case of n ) 5 in Scheme 2, only the E isomer (18)
was isolated. After the separation of E/Z isomers, the
trityl group in 18-24 was removed under acidic condi-
tions to provide the corresponding alcohols (25-31),
which were oxidized to the corresponding carboxylic
acids (32-38) by pyridinium dichromate in DMF. After
deprotection of the 4-methoxyphenyl group in 32-38,
Since the role of the alkyl chains in DAGs and DAG-
lactones is to facilitate partitioning into the lipid-rich
membrane environment, the lipophilicities of the com-
pounds have been correlated with their binding affini-
ties in a parabolic manner.14 It is desirable that non-
specific interactions be minimized not only to allow the
protein-ligand interaction to become dominant but also
to render the ligands physicochemically suitable as drug

4002 J ournal of Medicinal Chemistry, 2004, Vol. 47, No. 16
Kang et al.
Ta ble 1. Apparent Ki (nM) Values and log P of Synthesized DAG-bis-macrolactones
a
Reference 11.
the corresponding hydroxy acids (39-45) were cyclized
using Keck and Boden’s macrocyclization method18 to
produce 13-, 17-, 21-, and 25-membered macrolactones
(46-52), respectively. Finally, debenzylation of 46-52
afforded the target macrocyclic DAG-bis-lactones (53-
59).
ing the two terminal carbons at the 3 and 5 positions of
DAG-lactones 5 and 6, respectively. The resulting 56
(Ki ) 12.16 nM) and 57 (Ki ) 6.07 nM) showed ca. 6-fold
enhancement compared to 5 (Ki ) 77.85 nM) and 6 (Ki
) 35.09 nM), respectively. It is of interest to note that
macrocyclization resulted in a comparable entropic
advantage for both E- and Z-DAG-bis-lactone isomers
as reflected by the similar increase in binding affinity.
Furthermore, the log P values for 56 and 57 (log P )
3.85) are lower than parent lactones 5 and 6 (log P )
5.36) by 1.51 units. In a similar way, the macrocycliza-
tion of 7 and 8 produced [22.2.1] bicyclic systems 58 and
59, respectively. The Z isomer 59 (Ki ) 10.29 nM)
displayed only a modest ca. 2-fold increase in binding
affinity compared to 8 (Ki ) 24 nM), while the binding
affinity of the E isomer 58 (Ki ) 22.0 nM) was only a
little better than that of 7 (Ki ) 28 nM). These results
demonstrate that macrocyclization of DAG-lactones
provides PKC ligands with higher binding affinities and
lower lipophilicities.
Resu lts a n d Discu ssion
Biologica l Activitiy. The interaction of macrocyclic
DAG-bis-lactones 53-59 with PKC was assessed in
terms of the ability of the ligand to displace bound [20-
3H]phorbol 12,13-dibutyrate (PDBU) from the recom-
binant PKCR isozyme in the presence of phosphati-
dylserine as previously described.14 IC50 values were
determined by fitting the data points to the theoretical
noncooperative competitive inhibition curve. The Ki
values for inhibition of binding were calculated from the
corresponding IC50 values and are listed in Table 1. The
log P values of the lactones were calculated by the
fragment-based program KowWin 1.63.16 The binding
affinities of the macrocyclic DAG-bis-lactones were
compared with those reported for the parent DAG-
lactones (5-8), which were used as reference.11
The size of the macrolactone seems to be a critical
parameter. While the binding affinities for the larger
macrocyclic DAG-bis-lactones 58 and 59 were ca. 2-fold
weaker than the affinities for 56 and 57, four-carbon
smaller macrolactones also produced deficient ligands
The macrocyclic DAG-bis-lactones 56 and 57, bearing
a [18.2.1] bicyclic skeleton, were generated by connect-

DAG-bis-lactones
J ournal of Medicinal Chemistry, 2004, Vol. 47, No. 16 4003
F igu r e 3. Proposed models of PKCR-ligand complexes. Acyclic DAG-lactone 6 in sn-1 (a) and sn-2 (b) binding modes. Macrocyclic
DAG-bis-lactone 57 in sn-1 binding mode (c).
(54, Ki ) 107.2 nM; 55, Ki ) 52.7 nM) ca. 9-fold weaker
than 56 and 57. The macrolactone reduced by an
additional four carbons, 53, displayed very low affinity
(Ki ) 1,800 nM). This result indicates that the size and
lipophilicity of macrocyclic DAG-bis-lactones 56 and 57
appear to be optimal for membrane partitioning and
PKC activation. Previously, a parabolic dependence
between log(1/Ki) and log P had been reported for the
set of DAG-lactones bearing acyl or 3-alkylidene chains,
with an optimal log P for DAG-lactones between 5 and
6.14 In a similar manner, this macrocyclic DAG-bis-
lactone series showed a parabolic relationship between
binding affinity and lipophilicity with a maximum log-
(1/Ki) in the same range. The macrocyclic DAG-bis-
lactones also showed a geometric preference similar to
that described for DAG-lactones. The Z isomers of the
macrocyclic DAG-bis-lactones (55, 57, 59) consistently
exhibited about 2-fold greater potency than the corre-
sponding E isomers (54, 56, 58). Thus, the relationship
between binding affinity, lipophilicity, and geometry in
our series of macrocyclic DAG-bis-lactones shows a
pattern similar to that of the parent DAG-lactones.
headgroups, or with other hydrophilic elements, re-
quired for high-affinity binding under the conditions of
the biological assays.
To investigate the binding mode of the most potent
macrocyclic DAG-bis-lactone 57 and by comparison of
it to the corresponding acyclic DAG-lactone 6, both
compounds were docked into the C1b domain of PKCR
derived through homology modeling.19 By use of the
program Autodock 3.0, as previously described,20 com-
pounds 6 and 57 were evaluated with the number of
dockings set to 100. DAG-lactone 6 appears to bind
favoring the sn-2 binding mode [44% for sn-2 binding
(Figure 3a) versus 36% for sn-1 binding (Figure 3b)]
relative to the macrocyclic DAG-bis-lactone 57, which
seems to bind exclusively in a variant of the typical sn-1
binding mode (Figure 3c). Compounds 6 and 57 interact
with Thr12, Leu21, and Gly23 in the C1b domain of
PKCR, which correspond to Thr242, Leu251, and Gly253
in the full length protein. In the sn-1 mode of compound
6, the hydroxyl group engages in a bifurcated hydrogen
bond to the amide proton of Thr12 (1.8 Å) and the
carbonyl of Leu21 (1.9 Å), while the sn-1 carbonyl acts
as a hydrogen bond acceptor for the backbone nitrogen
of Gly23 (2.4 Å). (Note that the numbers should cor-
respond to the ones in the figure.) The sn-2 binding
mode for compound 6 shows a network of hydrogen
bonds similar to these amino acids. The hydroxyl group
makes equivalent hydrogen bonds to Thr12 (1.8 Å) and
Leu21 (1.8 Å), but it is the sn-2 carbonyl of the lactone
ring that now forms a hydrogen bond with Gly23 (1.6
Å). The preference of 6 for the sn-2 binding mode
correlates with the better quality of hydrogen bonds
formed in this modality. In the case of compound 57,
the hydroxyl group engages in an identical pattern of
hydrogen bonds to Thr12 (1.7 Å) and Leu21 (2.2 Å).
However, in this unique sn-1 binding mode the amide
proton of Gly23 makes a bifurcated hydrogen bond to
the sn-1 carbonyl (2.2 Å) and the sp3 oxygen (2.2 Å) of
the ester. In addition, this single sn-1 binding mode
reveals that the hydrophobic alkyl chain is fitted to the
highly conserved hydrophobic residues in PKCR, such
as Pro11, Phe13, Leu20, Tyr22, and Leu24. In particu-
lar, the alkyl chain of the macrolactone contacts closely
Molecu la r Mod elin g. Previously, the molecular
modeling studies revealed that DAG-lactones have two
possible binding orientations when they were docked
into the empty C1b domain derived from the crystal
coordinates of PKCδ in complex with phorbol 13-acetate.
These two apparently equivalent binding modes, sn-1
and sn-2, form a network of hydrogen bonds with amino
acids Thr242, Leu251, and Gly253 identical to those
formed by phorbol 13-acetate in the crystal structure
of the complex. The sn-1 (or sn-2) binding mode is
defined when the sn-1 (or sn-2) carbonyl, corresponding
to the carbonyl of the 5-acyloxymethyl (or the lactone),
and the hydroxyl group in the DAG-lactone are directly
bound to the protein by hydrogen bonding.9,10 In the two
binding alternatives, one of the two carbonyls of the
DAG lactone remained unengaged with the protein. It
has been hypothesized that this orphan pharmacophore
functions equivalently to the C-9(OH)/C-13(CdO) motif
in phorbol esters, which also appears to be free of
interactions in the phorbol ester/C1b complex, and is
presumably involved in interacting with phospholipid

4004 J ournal of Medicinal Chemistry, 2004, Vol. 47, No. 16
Kang et al.
20-(Tr ityloxy)-1-eicosa n ol (12): 1H NMR (CDCl3) δ 7.0-
7.5 (m, 15 H, CPh3), 3.59 (t, 2 H, J ) 6.6 Hz, CH2OH), 3.04 (t,
2 H, J ) 6.6 Hz, CH2OTr), 1.2-1.7 (m, 36 H, (CH2)18).
Gen er a l P r oced u r e for th e Syn th esis of 13-16. A
suspension of 9-12 (6 mmol) and 4 Å molecular sieves (3.88
g) in CH2Cl2 (40 mL) was treated with pyridinium chlorochro-
mate (3.88 g, 18 mmol) and stirred for 1 h at room tempera-
ture. The mixture was treated with ether and Celite and
stirred for 30 min. The suspension was filtered through a short
pad of silica gel, and the combined filtrates were concentrated
in vacuo. The residue was purified by flash column chroma-
tography on silica gel with EtOAc/hexanes (1:10) as eluant to
afford 13-16 as colorless oils in 70-80% yield.
the hydrophobic side chains of Leu20, Tyr22, and Leu24.
The role of hydrophobic residues in the C1b domain of
PKCR on ligand recognition has been investigated by
site-directed mutagenesis.21 Three hydrophobic resi-
dues, Leu250, Trp252, and Leu254, were identified as
essential residues for binding, and since these amino
acids correspond to Leu20, Tyr22, and Leu24 (Figure
3c), the hydrophobic interactions between the macro-
cyclic side chain and these amino acids may contribute
to the observed high binding affinity. Therefore, the
higher potency of compound 57 (Ki ) 6.07 nM) relative
to compound 6 (Ki ) 35.09 nM) may be explained by
extra hydrogen bonding and hydrophobic interactions
in addition to the entropy gain due to conformational
restriction.
8-(Tr ityloxy)-1-octa n a l (13): 1H NMR (CDCl3) δ 9.76 (t, 1
H, J ) 2.0 Hz, CHO), 7.15-7.5 (m, 15 H, CPh3), 3.04 (t, 2 H,
J ) 6.6 Hz, CH2OTr), 2.41 (dt, 2 H, J ) 2.0, 7.3 Hz, CH2CHO),
1.2-1.7 (m, 10 H, (CH2)5).
12-(Tr ityloxy)-1-d od eca n a l (14): 1H NMR (CDCl3) δ 9.75
(t, 1 H, J ) 2.0 Hz, CHO), 7.15-7.5 (m, 15 H, CPh3), 3.04 (t,
2 H, J ) 6.6 Hz, CH2OTr), 2.40 (dt, 2 H, J ) 2.0, 7.3 Hz, CH2-
CHO), 1.2-1.7 (m, 18 H, (CH2)9).
Con clu sion
An additional conformational restriction imposed on
DAG-lactones provided a new set of macrocyclic DAG-
bis-lactones, some of which displayed greater binding
affinities for PKC than conventional DAG-lactones with
reduced lipophilicity. Specifically, compound 57 exhib-
ited a high binding affinity for PKCR (Ki ) 6.07 nM),
which was 6-fold higher than the corresponding acyclic
3-alkylidene DAG-lactone 6. The SAR analysis demon-
strated a parabolic relationship between activity and
lipophilicity, as well as a predilection for the Z-alkyl-
idene isomers as the preferred ligands. Molecular dock-
ing studies revealed that the highly potent DAG-bis-
macrolactone 57 binds exclusively in the sn-1 binding
mode to the C1b domain of PKCR. The combination of
a highly favorable pattern of hydrogen bonding and
hydrophobic interactions with the expected entropy gain
due to conformational restriction appears to contribute
to its high binding affinity.
16-(Tr ityloxy)-1-h exa d eca n a l (15): 1H NMR (CDCl3) δ
9.74 (t, 1 H, J ) 2.0 Hz, CHO), 7.15-7.5 (m, 15 H, CPh3), 3.04
(t, 2 H, J ) 6.6 Hz, CH2OTr), 2.40 (dt, 2 H, J ) 2.0, 7.3 Hz,
CH2CHO), 1.2-1.7 (m, 26 H, (CH2)13).
1
20-(Tr ityloxy)-1-eicosa n a l (16): H NMR (CDCl3) δ 9.76
(t, 1 H, J ) 2.0 Hz, CHO), 7.15-7.5 (m, 15 H, CPh3), 3.04 (t,
2 H, J ) 6.6 Hz, CH2OTr), 2.41 (dt, 2 H, J ) 2.0, 7.3 Hz, CH2-
CHO), 1.2-1.7 (m, 34 H, (CH2)17).
Gen er a l P r oced u r e for th e Syn th esis 18-24. A stirred
solution of 17 (1.03 g, 3.0 mmol) in THF (6 mL) was cooled to
-78 °C and treated dropwise with lithium bis(trimethylsilyl)-
amide (1 M in THF, 4.5 mL, 4.5 mmol). After being stirred for
30 min at -78 °C, the mixture was treated with a solution of
the aldehyde (13-16, 3.6 mmol) in THF (3.6 mL) and stirred
for 2 h at the same temperature. The reaction was quenched
by the slow addition of a saturated aqueous solution of
ammonium chloride, and the mixture was extracted with ether
several times. The combined organic layers were washed with
H2O and brine, dried over MgSO4, and concentrated in vacuo.
The residue was purified by flash column chromatography on
silica gel with EtOAc/hexanes (1:4) as eluant to give the
intermediate â-hydroxylactones as an oil. A solution of the
above compound in CH2Cl2 (6 mL) was cooled to 0 °C and
treated with triethylamine (1.1 mL, 8 mmol) and methane-
sulfonyl chloride (0.3 mL, 4.0 mmol). The mixture was stirred
at 0 °C for 30 min and then for 2 h at room temperature. 1,8-
Diazabicyclo[5.4.0]undec-7-ene (DBU, 1.2 mL, 8.0 mmol) was
added at 0 °C, and the resulting solution was stirred for 30
min. The reaction mixture was concentrated in vacuo and the
residue was purified by flash column chromatography on silica
gel with EtOAc/hexanes (1:10) as eluant to afford a mixture
of E and Z isomers (18-24) as colorless oils in 45-52% yield.
5-(Ben zyloxy)m eth yl-5-(4-m eth oxyp h en oxy)m eth yl-3-
[(E)-8-tr ityloxyoctylid en e]tetr a h yd r o-2-fu r a n on e (18): 1H
NMR (CDCl3) δ 7.2-7.5 (m, 20 H, phenyl), 6.80 (s, 4 H, Ar),
6.75 (m, 1 H, >CdCH), 4.58 (s, 2 H, PhCH2O), 4.02 (AB q, 2
H, J ) 9.5 Hz, CH2Ar), 3.74 (s, 3 H, OCH3), 3.66 (AB q, 2 H,
J ) 10.2 Hz, BnCH2O), 3.03 (t, 2 H, J ) 6.6 Hz, CH2OTr),
2.83 (m, 2 H, H-4), 2.14 (q, 2 H, >CdCH-CH2), 1.25-1.65 (m,
10 H, (CH2)5).
5-(Ben zyloxy)m eth yl-5-(4-m eth oxyp h en oxy)m eth yl-3-
[(E)-12-tr ityloxydodecyliden e]tetr ah ydr o-2-fu r an on e (19):
1H NMR (CDCl3) δ 7.2-7.5 (m, 20 H, phenyl), 6.80 (s, 4 H,
Ar), 6.75 (m, 1 H, >CdCH), 4.58 (s, 2 H, PhCH2O), 4.02 (AB
q, 2 H, J ) 9.7 Hz, CH2Ar), 3.75 (s, 3 H, OCH3), 3.67 (AB q, 2
H, J ) 10.2 Hz, BnCH2O), 3.03 (t, 2 H, J ) 6.6 Hz, CH2OTr),
2.83 (m, 2 H, H-4), 2.16 (q, 2 H, >CdCH-CH2), 1.2-1.65 (m,
18 H, (CH2)9).
5-(Ben zyloxy)m eth yl-5-(4-m eth oxyp h en oxy)m eth yl-3-
[(Z)-12-tr ityloxydodecyliden e]tetr ah ydr o-2-fu r an on e (20):
1H NMR (CDCl3) δ 7.15-7.5 (m, 20 H, phenyl), 6.80 (s, 4 H,
Ar), 6.18 (m, 1 H, >CdCH), 4.57 (m, 2 H, PhCH2O), 4.00 (AB
q, 2 H, J ) 9.7 Hz, CH2Ar), 3.73 (s, 3 H, OCH3), 3.64 (AB q, 2
Exp er im en ta l Section
All chemical reagents were commercially available. Melting
points were determined on a melting point Bu¨chi B-540
apparatus and are uncorrected. Silica gel column chromatog-
raphy was performed on silica gel 60, 230-400 mesh, Merck.
Proton NMR spectra were recorded on a J EOL J NM-LA 300
at 300 MHz. Chemical shifts are reported in ppm units with
Me4Si as a reference standard. Infrared spectra were recorded
on a Perkin-Elmer 1710 series FTIR. Mass spectra were
recorded on a VG Trio-2 GC-MS instrument. Elemental
analyses were performed with an EA 1110 automatic elemen-
tal analyzer, CE Instruments.
Gen er a l P r oced u r e for th e Syn th esis of 9-12. A solu-
tion of diol (10 mmol) in DMF (10 mL) was treated with
pyridine (1.6 mL, 20 mmol) and trityl chloride (2.78 g, 10
mmol) and stirred for 1 h at room temperature. The mixture
was diluted with H2O and extracted with EtOAc several times.
The combined organic layers were washed with H2O and brine,
dried over MgSO4, and concentrated in vacuo. The residue was
purified by flash column chromatography on silica gel with
EtOAc/hexanes (1:4) as eluant to afford 9-12 as colorless oils
in 60-70% yield.
8-(Tr ityloxy)-1-octa n ol (9): 1H NMR (CDCl3) δ 7.0-7.5 (m,
15 H, CPh3), 3.59 (t, 2 H, J ) 6.6 Hz, CH2OH), 3.04 (t, 2 H, J
) 6.6 Hz, CH2OTr), 1.2-1.7 (m, 12 H, (CH2)6).
12-(Tr ityloxy)-1-d od eca n ol (10): 1H NMR (CDCl3) δ 7.0-
7.5 (m, 15 H, CPh3), 3.62 (t, 2 H, J ) 6.6 Hz, CH2OH), 3.03 (t,
2 H, J ) 6.6 Hz, CH2OTr), 1.2-1.7 (m, 20 H, (CH2)10).
16-(Tr ityloxy)-1-h exa d eca n ol (11): 1H NMR (CDCl3) δ
7.0-7.5 (m, 15 H, CPh3), 3.59 (t, 2 H, J ) 6.6 Hz, CH2OH),
3.04 (t, 2 H, J ) 6.6 Hz, CH2OTr), 1.2-1.7 (m, 28 H, (CH2)14).

DAG-bis-lactones
J ournal of Medicinal Chemistry, 2004, Vol. 47, No. 16 4005
H, J ) 10.2 Hz, BnCH2O), 3.04 (t, 2 H, J ) 6.6 Hz, CH2OTr),
2.88 (m, 2 H, H-4), 2.72 (m, 2 H, >CdCH-CH2), 1.2-1.65 (m,
18 H, (CH2)9).
Ar), 6.20 (m, 1 H, >CdCH), 4.58 (AB q, 2 H, J ) 12.2 Hz,
PhCH2O), 4.01 (AB q, 2 H, J ) 9.7 Hz, CH2Ar), 3.76 (s, 3 H,
OCH3), 3.6-3.7 (m, 4 H, BnCH2O and CH2OH), 2.90 (m, 2 H,
H-4), 2.72 (m, 2 H, >CdCH-CH2), 1.2-1.65 (m, 26 H, (CH2)13).
5-(Ben zyloxy)m eth yl-3-[(E)-20-h yd r oxyeicosylid en e]-
5-(4-m eth oxyph en oxy)m eth yltetr ah ydr o-2-fu r an on e (30):
1H NMR (CDCl3) δ 7.25-7.35 (m, 5 H, phenyl), 6.80 (s, 4 H,
Ar), 6.75 (m, 1 H, >CdCH), 4.59 (s, 2 H, PhCH2O), 4.03 (AB
q, 2 H, J ) 9.7 Hz, CH2Ar), 3.76 (s, 3 H, OCH3), 3.6-3.7 (m,
4 H, BnCH2O and CH2OH), 2.84 (m, 2 H, H-4), 2.16 (q, 2 H,
>CdCH-CH2), 1.2-1.65 (m, 34 H, (CH2)17).
5-(Ben zyloxy)m eth yl-5-(4-m eth oxyp h en oxy)m eth yl-3-
[(E )-16-t r it y lo x y h e x a d e c y lid e n e ]t e t r a h y d r o -2-fu r a -
n on e (21): 1H NMR (CDCl3) δ 7.2-7.5 (m, 20 H, phenyl), 6.80
(s, 4 H, Ar), 6.75 (m, 1 H, >CdCH), 4.58 (s, 2 H, PhCH2O),
4.02 (AB q, 2 H, J ) 9.7 Hz, CH2Ar), 3.75 (s, 3 H, OCH3), 3.67
(AB q, 2 H, J ) 10.2 Hz, BnCH2O), 3.03 (t, 2 H, J ) 6.6 Hz,
CH2OTr), 2.84 (m, 2 H, H-4), 2.16 (q, 2 H, >CdCH-CH2), 1.2-
1.65 (m, 26 H, (CH2)13).
5-(Ben zyloxy)m eth yl-5-(4-m eth oxyp h en oxy)m eth yl-3-
[(Z)-16-t r it y lo x y h e x a d e c y lid e n e ]t e t r a h y d r o -2-fu r a -
n on e (22): 1H NMR (CDCl3) δ 7.15-7.5 (m, 20 H, phenyl),
6.80 (s, 4 H, Ar), 6.19 (m, 1 H, >CdCH), 4.57 (m, 2 H,
PhCH2O), 4.01 (AB q, 2 H, J ) 9.7 Hz, CH2Ar), 3.76 (s, 3 H,
OCH3), 3.65 (AB q, 2 H, J ) 10.2 Hz, BnCH2O), 3.03 (t, 2 H,
J ) 6.6 Hz, CH2OTr), 2.88 (m, 2 H, H-4), 2.72 (m, 2 H, >Cd
CH-CH2), 1.2-1.65 (m, 26 H, (CH2)13).
5-(Ben zyloxy)m eth yl-5-(4-m eth oxyp h en oxy)m eth yl-3-
[(E)-20-tr ityloxyeicosylid en e]tetr a h yd r o-2-fu r a n on e (23):
1H NMR (CDCl3) δ 7.2-7.5 (m, 20 H, phenyl), 6.80 (s, 4 H,
Ar), 6.75 (m, 1 H, >CdCH), 4.58 (s, 2 H, PhCH2O), 4.02 (AB
q, 2 H, J ) 9.7 Hz, CH2Ar), 3.76 (s, 3 H, OCH3), 3.67 (AB q, 2
H, J ) 10.2 Hz, BnCH2O), 3.03 (t, 2 H, J ) 6.6 Hz, CH2OTr),
2.84 (m, 2 H, H-4), 2.16 (q, 2 H, >CdCH-CH2), 1.2-1.65 (m,
34 H, (CH2)17).
5-(Ben zyloxy)m eth yl-5-(4-m eth oxyp h en oxy)m eth yl-3-
[(Z)-20-tr ityloxyeicosylid en e]tetr a h yd r o-2-fu r a n on e (24):
1H NMR (CDCl3) δ 7.15-7.5 (m, 20 H, phenyl), 6.80 (s, 4 H,
Ar), 6.20 (m, 1 H, >CdCH), 4.58 (AB q, 2 H, J ) 11.9 Hz,
PhCH2O), 4.01 (AB q, 2 H, J ) 9.7 Hz, CH2Ar), 3.76 (s, 3 H,
OCH3), 3.65 (AB q, 2 H, J ) 10.2 Hz, BnCH2O), 3.03 (t, 2 H,
J ) 6.6 Hz, CH2OTr), 2.90 (m, 2 H, H-4), 2.72 (m, 2 H, >Cd
CH-CH2), 1.2-1.65 (m, 34 H, (CH2)17).
Gen er a l P r oced u r e for th e Syn th esis 25-31. A solution
of 18-24 (0.5 mmol) in ether (3 mL) was treated with formic
acid (3 mL) and stirred for 1 h at room temperature. The
mixture was neutralized with solid sodium bicarbonate, fil-
tered, and concentrated in vacuo. The residue was purified by
flash column chromatography on silica gel with EtOAc/hexanes
(1:4) as eluant to afford 25-31 as colorless oils in almost
quantitative yield.
5-(Ben zyloxy)m eth yl-3-[(Z)-20-h yd r oxyeicosylid en e]-
5-(4-m eth oxyph en oxy)m eth yltetr ah ydr o-2-fu r an on e (31):
1H NMR (CDCl3) δ 7.25-7.35 (m, 5 H, phenyl), 6.81 (s, 4 H,
Ar), 6.20 (m, 1 H, >CdCH), 4.58 (AB q, 2 H, J ) 12.2 Hz,
PhCH2O), 4.01 (AB q, 2 H, J ) 9.7 Hz, CH2Ar), 3.76 (s, 3 H,
OCH3), 3.6-3.7 (m, 4 H, BnCH2O and CH2OH), 2.90 (m, 2 H,
H-4), 2.72 (m, 2 H, >CdCH-CH2), 1.2-1.65 (m, 34 H, (CH2)17).
Gen er a l P r oced u r e for th e Syn th esis of 32-38. A sol-
ution of 25-31 (0.5 mmol) in DMF (4 mL) was treated with
pyridinium dichromate (1.13 g, 3.0 mmol) and stirred for 24 h
at room temperature. The mixture was diluted with EtOAc,
washed with H2O and brine, dried over MgSO4, and concen-
trated in vacuo. The residue was purified by flash column
chromatography on silica gel with EtOAc/hexanes (1:1) as
eluant to afford 32-38 as colorless oils in 80-88% yield.
5-(Ben zyloxy)m et h yl-3-[(E)-8-ca r b oxyh ep t ylid en e]-5-
(4-m eth oxyp h en oxy)m eth yltetr a h yd r o-2-fu r a n on e (32):
1H NMR (CDCl3) δ 7.25-7.35 (m, 5 H, phenyl), 6.80 (s, 4 H,
Ar), 6.75 (m, 1 H, >CdCH), 4.58 (s, 2 H, PhCH2O), 4.03 (AB
q, 2 H, J ) 9.7 Hz, CH2Ar), 3.76 (s, 3 H, OCH3), 3.67 (AB q, 2
H, J ) 10.2 Hz, BnCH2O), 2.84 (m, 2 H, H-4), 2.27 (t, 2 H, J
) 7.5 Hz, CH2CO2H), 2.14 (q, 2 H, >CdCH-CH2), 1.25-1.7
(m, 8 H, (CH2)4).
5-(Ben zyloxy)m eth yl-3-[(E)-12-ca r boxyu n d ecylid en e]-
5-(4-m eth oxyph en oxy)m eth yltetr ah ydr o-2-fu r an on e (33):
1H NMR (CDCl3) δ 7.25-7.35 (m, 5 H, phenyl), 6.80 (s, 4 H,
Ar), 6.75 (m, 1 H, >CdCH), 4.58 (s, 2 H, PhCH2O), 4.03 (AB
q, 2 H, J ) 9.7 Hz, CH2Ar), 3.76 (s, 3 H, OCH3), 3.67 (AB q, 2
H, J ) 10.2 Hz, BnCH2O), 2.84 (m, 2 H, H-4), 2.27 (t, 2 H, J
) 7.5 Hz, CH2CO2H), 2.14 (q, 2 H, >CdCH-CH2), 1.25-1.7
(m, 16 H, (CH2)8).
5-(Ben zyloxy)m eth yl-3-[(Z)-12-ca r boxyu n d ecylid en e]-
5-(4-m eth oxyph en oxy)m eth yltetr ah ydr o-2-fu r an on e (34):
1H NMR (CDCl3) δ 7.25-7.35 (m, 5 H, phenyl), 6.80 (s, 4 H,
Ar), 6.20 (m, 1 H, >CdCH), 4.58 (AB q, 2 H, J ) 12.2 Hz,
PhCH2O), 4.01 (AB q, 2 H, J ) 9.7 Hz, CH2Ar), 3.75 (s, 3 H,
OCH3), 3.66 (AB q, 2 H, J ) 10.2 Hz, BnCH2O), 2.90 (m, 2 H,
H-4), 2.71 (m, 2 H, >CdCH-CH2), 2.33 (t, 2 H, J ) 7.5 Hz,
CH2CO2H), 1.25-1.7 (m, 16 H, (CH2)8).
5-(Ben zyloxy)m eth yl-3-[(E)-8-h yd r oxyoctylid en e]-5-(4-
m eth oxyp h en oxy)m eth yltetr a h yd r o-2-fu r a n on e (25): 1H
NMR (CDCl3) δ 7.25-7.35 (m, 5 H, phenyl), 6.80 (s, 4 H, Ar),
6.75 (m, 1 H, >CdCH), 4.58 (s, 2 H, PhCH2O), 4.03 (AB q, 2
H, J ) 9.7 Hz, CH2Ar), 3.76 (s, 3 H, OCH3), 3.6-3.7 (m, 4 H,
BnCH2O and CH2OH), 2.84 (m, 2 H, H-4), 2.16 (q, 2 H, >Cd
CH-CH2), 1.2-1.65 (m, 10 H, (CH2)5).
5-(Ben zyloxy)m eth yl-3-[(E)-12-h yd r oxyd od ecylid en e]-
5-(4-m eth oxyph en oxy)m eth yltetr ah ydr o-2-fu r an on e (26):
1H NMR (CDCl3) δ 7.25-7.35 (m, 5 H, phenyl), 6.80 (s, 4 H,
Ar), 6.75 (m, 1 H, >CdCH), 4.58 (s, 2 H, PhCH2O), 4.03 (AB
q, 2 H, J ) 9.7 Hz, CH2Ar), 3.76 (s, 3 H, OCH3), 3.6-3.7 (m,
4 H, BnCH2O and CH2OH), 2.84 (m, 2 H, H-4), 2.16 (q, 2 H,
>CdCH-CH2), 1.2-1.65 (m, 18 H, (CH2)9).
5-(Ben zyloxy)m eth yl-3-[(Z)-12-h yd r oxyd od ecylid en e]-
5-(4-m eth oxyph en oxy)m eth yltetr ah ydr o-2-fu r an on e (27):
1H NMR (CDCl3) δ 7.25-7.35 (m, 5 H, phenyl), 6.81 (s, 4 H,
Ar), 6.17 (m, 1 H, >CdCH), 4.58 (AB q, 2 H, J ) 12.2 Hz,
PhCH2O), 4.01 (AB q, 2 H, J ) 9.7 Hz, CH2Ar), 3.76 (s, 3 H,
OCH3), 3.6-3.7 (m, 4 H, BnCH2O and CH2OH), 2.90 (m, 2 H,
H-4), 2.72 (m, 2 H, >CdCH-CH2), 1.2-1.65 (m, 18 H, (CH2)9).
5-(Ben zyloxy)m eth yl-3-[(E)-16-h ydr oxyh exadecyliden e]-
5-(4-m eth oxyph en oxy)m eth yltetr ah ydr o-2-fu r an on e (28):
1H NMR (CDCl3) δ 7.25-7.35 (m, 5 H, phenyl), 6.80 (s, 4 H,
Ar), 6.75 (m, 1 H, >CdCH), 4.59 (s, 2 H, PhCH2O), 4.03 (AB
q, 2 H, J ) 9.7 Hz, CH2Ar), 3.76 (s, 3 H, OCH3), 3.6-3.7 (m,
4 H, BnCH2O and CH2OH), 2.84 (m, 2 H, H-4), 2.16 (q, 2 H,
>CdCH-CH2), 1.2-1.65 (m, 26 H, (CH2)13).
5-(Ben zyloxy)m et h yl-3-[(E)-16-ca r b oxyp en t a d ecyli-
d en e]-5-(4-m et h oxyp h en oxy)m et h ylt et r a h yd r o-2-fu r a -
n on e (35): 1H NMR (CDCl3) δ 7.25-7.35 (m, 5 H, phenyl),
6.80 (s, 4 H, Ar), 6.75 (m, 1 H, >CdCH), 4.58 (s, 2 H, PhCH2O),
4.02 (AB q, 2 H, J ) 9.7 Hz, CH2Ar), 3.76 (s, 3 H, OCH3), 3.67
(AB q, 2 H, J ) 10.2 Hz, BnCH2O), 2.84 (m, 2 H, H-4), 2.34 (t,
2 H, J ) 7.5 Hz, CH2CO2H), 2.14 (q, 2 H, >CdCH-CH2), 1.25-
1.7 (m, 24 H, (CH2)12).
5-(Ben zyloxy)m et h yl-3-[(Z)-16-ca r b oxyp en t a d ecyli-
d en e]-5-(4-m et h oxyp h en oxy)m et h ylt et r a h yd r o-2-fu r a -
n on e (36): 1H NMR (CDCl3) δ 7.25-7.35 (m, 5 H, phenyl),
6.80 (s, 4 H, Ar), 6.20 (m, 1 H, >CdCH), 4.59 (AB q, 2 H, J )
12.2 Hz, PhCH2O), 4.01 (AB q, 2 H, J ) 9.7 Hz, CH2Ar), 3.76
(s, 3 H, OCH3), 3.66 (AB q, 2 H, J ) 10.2 Hz, BnCH2O), 2.90
(m, 2 H, H-4), 2.72 (m, 2 H, >CdCH-CH2), 2.34 (t, 2 H, J )
7.5 Hz, CH2CO2H), 1.25-1.7 (m, 24 H, (CH2)12).
5-(Ben zyloxy)m eth yl-3-[(E)-20-car boxyn on adecyliden e]-
5-(4-m eth oxyph en oxy)m eth yltetr ah ydr o-2-fu r an on e (37):
1H NMR (CDCl3) δ 7.25-7.35 (m, 5 H, phenyl), 6.80 (s, 4 H,
Ar), 6.75 (m, 1 H, >CdCH), 4.58 (s, 2 H, PhCH2O), 4.03 (AB
q, 2 H, J ) 9.7 Hz, CH2Ar), 3.76 (s, 3 H, OCH3), 3.67 (AB q, 2
H, J ) 10.2 Hz, BnCH2O), 2.84 (m, 2 H, H-4), 2.34 (t, 2 H, J
) 7.5 Hz, CH2CO2H), 2.16 (q, 2 H, >CdCH-CH2), 1.25-1.7
(m, 32 H, (CH2)16).
5-(Ben zyloxy)m eth yl-3-[(Z)-16-h ydr oxyh exadecyliden e]-
5-(4-m eth oxyph en oxy)m eth yltetr ah ydr o-2-fu r an on e (29):
1H NMR (CDCl3) δ 7.25-7.35 (m, 5 H, phenyl), 6.81 (s, 4 H,

4006 J ournal of Medicinal Chemistry, 2004, Vol. 47, No. 16
Kang et al.
5-(Ben zyloxy)m eth yl-3-[(Z)-20-car boxyn on adecyliden e]-
5-(4-m eth oxyph en oxy)m eth yltetr ah ydr o-2-fu r an on e (38):
1H NMR (CDCl3) δ 7.2-7.35 (m, 5 H, phenyl), 6.81 (s, 4 H,
Ar), 6.20 (m, 1 H, >CdCH), 4.59 (AB q, 2 H, J ) 12.2 Hz,
PhCH2O), 4.01 (AB q, 2 H, J ) 9.7 Hz, CH2Ar), 3.76 (s, 3 H,
OCH3), 3.66 (AB q, 2 H, J ) 10.2 Hz, BnCH2O), 2.90 (m, 2 H,
H-4), 2.72 (m, 2 H, >CdCH-CH2), 2.35 (t, 2 H, J ) 7.5 Hz,
CH2CO2H), 1.25-1.7 (m, 32 H, (CH2)16).
Gen er a l P r oced u r e for th e Syn th esis of 39-45. A
solution of 32-38 (0.4 mmol) in CH3CN/H2O (4:1, 5 mL) was
cooled to 0 °C and treated with ammonium cerium(IV) nitrate
(438 mg, 0.8 mmol). After being stirred for 30 min at 0 °C, the
reaction mixture was diluted with CH2Cl2. The organic layer
was washed with H2O and brine, dried over MgSO4, and
concentrated in vacuo. The residue was purified by flash
column chromatography on silica gel with only EtOAc as
eluant to afford 39-45 as colorless oils in 75-82% yield.
5-(Ben zyloxy)m et h yl-3-[(E)-8-ca r b oxyh ep t ylid en e]-5-
h yr oxym eth yltetr ah ydr o-2-fu r an on e (39): 1H NMR (CDCl3)
δ 7.25-7.35 (m, 5 H, phenyl), 6.69 (m, 1 H, >CdCH), 4.55 (s,
2 H, PhCH2O), 3.72 (AB q, 2 H, J ) 10.2 Hz, BnCH2O), 3.56
(AB q, 2 H, J ) 10.2 Hz, CH2OH), 2.75 (m, 2 H, H-4), 2.30 (t,
2 H, J ) 7.5 Hz, CH2CO2H), 2.14 (q, 2 H, >CdCH-CH2), 1.25-
1.7 (m, 8 H, (CH2)4).
mixture was rapidly stirred at room temperature and concen-
trated in vacuo. The residue was purified by flash column
chromatography on silica gel with EtOAc/hexanes (1:10) as
eluant to afford 46-52 as colorless oils in 60-70% yield.
1-(Ben zyloxy)m eth yl-3,14-dioxabicyclo[10.2.1]pen tadec-
11(E)-en e-4,13-d ion e (46): 1H NMR (CDCl3) δ 7.25-7.35 (m,
5 H, phenyl), 6.55 (m, 1 H, >CdCH), 4.98 (d, 1 H, J ) 12.2
Hz, OCOCH2), 4.55 (AB q, 2 H, J ) 12 Hz, PhCH2O), 3.88 (d,
1 H, J ) 12.2 Hz, OCOCH2), 3.60 (s, 2 H, BnCH2O), 2.70 (m,
2 H, H-4), 2.28 (t, 2 H, J ) 7.5 Hz, CH2CO2), 2.15 (m, 2 H,
>CdCH-CH2), 1.25-1.7 (m, 8 H, (CH2)4).
1-(Ben zyloxy)m eth yl-3,18-dioxabicyclo[14.2.1]n on adec-
15(E)-en e-4,17-d ion e (47): 1H NMR (CDCl3) δ 7.25-7.35 (m,
5 H, phenyl), 6.75 (m, 1 H, >CdCH), 4.58 (AB q, 2 H, J )
12.2 Hz, PhCH2O), 4.24 (s, 2 H, OCOCH2), 3.55 (s, 2 H,
BnCH2O), 2.80 (m, 2 H, H-4), 2.28 (t, 2 H, J ) 7.5 Hz, CH2-
CO2), 2.15 (m, 2 H, >CdCH-CH2), 1.2-1.7 (m, 16 H, (CH2)8).
1-(Ben zyloxy)m eth yl-3,18-dioxabicyclo[14.2.1]n on adec-
15(Z)-en e-4,17-d ion e (48): 1H NMR (CDCl3) δ 7.25-7.35 (m,
5 H, phenyl), 6.24 (m, 1 H, >CdCH), 4.57 (AB q, 2 H, J )
12.2 Hz, PhCH2O), 4.25 (AB q, 2 H, OCOCH2), 3.53 (AB q, 2
H, J ) 10 Hz, BnCH2O), 2.8-3.0 (m, 3 H, H-4 and >CdCH-
CH2), 2.2-2.4 (m, 3 H, CH2CO2 and >CdCH-CH2), 1.2-1.7
(m, 16 H, (CH2)8).
5-(Ben zyloxy)m eth yl-3-[(E)-12-ca r boxyu n d ecylid en e]-
5-h yd r oxym eth yltetr a h yd r o-2-fu r a n on e (40): 1H NMR
(CDCl3) δ 7.25-7.35 (m, 5 H, phenyl), 6.73 (m, 1 H, >CdCH),
4.56 (s, 2 H, PhCH2O), 3.72 (AB q, 2 H, J ) 10.2 Hz, BnCH2O),
3.58 (AB q, 2 H, J ) 10.2 Hz, CH2OH), 2.74 (m, 2 H, H-4),
2.34 (t, 2 H, J ) 7.5 Hz, CH2CO2H), 2.15 (q, 2 H, >CdCH-
CH2), 1.25-1.7 (m, 16 H, (CH2)8).
1-(Ben zyloxy)m eth yl-3,22-d ioxa bicyclo[18.2.1]tr ieicos-
19(E)-en e-4,21-d ion e (49): 1H NMR (CDCl3) δ 7.25-7.35 (m,
5 H, phenyl), 6.74 (m, 1 H, >CdCH), 4.58 (AB q, 2 H, J )
12.2 Hz, PhCH2O), 4.25 (AB q, 2 H, J ) 12 Hz, OCOCH2), 3.56
(s, 2 H, BnCH2O), 2.78 (m, 2 H, H-4), 2.28 (t, 2 H, J ) 7.5 Hz,
CH2CO2), 2.15 (m, 2 H, >CdCH-CH2), 1.2-1.7 (m, 24 H,
(CH2)12).
5-(Ben zyloxy)m eth yl-3-[(Z)-12-ca r boxyu n d ecylid en e]-
5-h yd r oxym eth yltetr a h yd r o-2-fu r a n on e (41): 1H NMR
(CDCl3) δ 7.25-7.35 (m, 5 H, phenyl), 6.20 (m, 1 H, >CdCH),
4.56 (AB q, 2 H, J ) 12.2 Hz, PhCH2O), 3.70 (AB q, 2 H, J )
10.2 Hz, BnCH2O), 3.56 (AB q, 2 H, J ) 10.2 Hz, CH2OH),
2.80 (m, 2 H, H-4), 2.68 (m, 2 H, >CdCH-CH2), 2.33 (t, 2 H,
J ) 7.3 Hz, CH2CO2H), 1.2-1.7 (m, 16 H, (CH2)8).
1-(Ben zyloxy)m eth yl-3,22-d ioxa bicyclo[18.2.1]tr ieicos-
19(Z)-en e-4,21-d ion e (50): 1H NMR (CDCl3) δ 7.25-7.35 (m,
5 H, phenyl), 6.20 (m, 1 H, >CdCH), 4.57 (AB q, 2 H, J )
12.2 Hz, PhCH2O), 4.25 (s, 2 H, OCOCH2), 3.53 (AB q, 2 H, J
) 10 Hz, BnCH2O), 3.12 (m, 1 H, >CdCH-CH2), 2.80 (m, 2
H, H-4), 2.2-2.4 (m, 3 H, CH2CO2 and >CdCH-CH2), 1.2-
1.7 (m, 24 H, (CH2)12).
5-(Ben zyloxy)m et h yl-3-[(E)-16-ca r b oxyp en t a d ecyli-
d en e]-5-h yd r oxym eth yltetr a h yd r o-2-fu r a n on e (42): 1H
NMR (CDCl3) δ 7.25-7.35 (m, 5 H, phenyl), 6.74 (m, 1 H, >Cd
CH), 4.58 (s, 2 H, PhCH2O), 3.72 (AB q, 2 H, J ) 10.2 Hz,
BnCH2O), 3.58 (AB q, 2 H, CH2OH), 2.74 (m, 2 H, H-4), 2.33
(t, 2 H, J ) 7.5 Hz, CH2CO2H), 2.15 (q, 2 H, >CdCH-CH2),
1.25-1.7 (m, 24 H, (CH2)12).
1-(Ben zyloxy)m eth yl-3,26-d ioxa bicyclo[22.2.1]h ep ta ei-
cos-23(E)-en e-4,25-d ion e (51): 1H NMR (CDCl3) δ 7.25-7.35
(m, 5 H, phenyl), 6.73 (m, 1 H, >CdCH), 4.58 (AB q, 2 H, J )
12.2 Hz, PhCH2O), 4.25 (AB q, 2 H, J ) 12 Hz, OCOCH2), 3.56
(s, 2 H, BnCH2O), 2.76 (m, 2 H, H-4), 2.28 (t, 2 H, J ) 7.5 Hz,
CH2CO2), 2.16 (m, 2 H, >CdCH-CH2), 1.2-1.7 (m, 32 H,
(CH2)16).
5-(Ben zyloxy)m et h yl-3-[(Z)-16-ca r b oxyp en t a d ecyli-
d en e]-5-h yd r oxym eth yltetr a h yd r o-2-fu r a n on e (43): 1H
NMR (CDCl3) δ 7.25-7.35 (m, 5 H, phenyl), 6.20 (m, 1 H, >Cd
CH), 4.56 (AB q, 2 H, J ) 12.2 Hz, PhCH2O), 3.70 (AB q, 2 H,
J ) 10.2 Hz, BnCH2O), 3.56 (AB q, 2 H, J ) 10.2 Hz, CH2-
OH), 2.81 (m, 2 H, H-4), 2.68 (m, 2 H, >CdCH-CH2), 2.34 (t,
2 H, J ) 7.3 Hz, CH2CO2H), 1.2-1.7 (m, 24 H, (CH2)12).
5-(Ben zyloxy)m eth yl-3-[(E)-20-car boxyn on adecyliden e]-
5-h yd r oxym eth yltetr a h yd r o-2-fu r a n on e (44): 1H NMR
(CDCl3) δ 7.25-7.35 (m, 5 H, phenyl), 6.75 (m, 1 H, >CdCH),
4.56 (s, 2 H, PhCH2O), 3.73 (AB q, 2 H, J ) 10.2 Hz, BnCH2O),
3.58 (AB q, 2 H, CH2OH), 2.75 (m, 2 H, H-4), 2.34 (t, 2 H, J )
7.5 Hz, CH2CO2H), 2.15 (q, 2 H, >CdCH-CH2), 1.25-1.7 (m,
32 H, (CH2)16).
5-(Ben zyloxy)m eth yl-3-[(Z)-20-car boxyn on adecyliden e]-
5-h yd r oxym eth yltetr a h yd r o-2-fu r a n on e (45): 1H NMR
(CDCl3) δ 7.25-7.35 (m, 5 H, phenyl), 6.20 (m, 1 H, >CdCH),
4.56 (AB q, 2 H, J ) 12.2 Hz, PhCH2O), 3.71 (AB q, 2 H, J )
10.2 Hz, BnCH2O), 3.57 (AB q, 2 H, J ) 10.2 Hz, CH2OH),
2.81 (m, 2 H, H-4), 2.69 (m, 2 H, >CdCH-CH2), 2.35 (t, 2 H,
J ) 7.3 Hz, CH2CO2H), 1.2-1.7 (m, 32 H, (CH2)16).
1-(Ben zyloxy)m eth yl-3,26-d ioxa bicyclo[22.2.1]h ep ta ei-
cos-23(Z)-en e-4,25-d ion e (52): 1H NMR (CDCl3) δ 7.25-7.35
(m, 5 H, phenyl), 6.19 (m, 1 H, >CdCH), 4.57 (AB q, 2 H, J )
12.2 Hz, PhCH2O), 4.25 (s, 2 H, OCOCH2), 3.54 (AB q, 2 H, J
) 10 Hz, BnCH2O), 2.95 (m, 1 H, >CdCH-CH2), 2.82 (m, 2
H, H-4), 2.48 (m, 1 H, >CdCH-CH2), 2.29 (m, 3 H, J ) 7.3
Hz, CH2CO2), 1.2-1.7 (m, 32 H, (CH2)16).
Gen er a l P r oced u r e for th e Syn th esis of 53-59. A
stirred solution of 46-52 (0.2 mmol) in CH2Cl2 (4 mL) was
cooled to -78 °C and treated dropwise with boron trichloride
(1 M, 0.6 mL, 0.6 mmol). After being stirred for 2 h at - 78
°C, the reaction mixture was quenched with the addition of
saturated NaHCO3 solution and immediately partitioned
between ether and NaHCO3 solution. The organic layer was
washed with H2O and brine, dried over MgSO4, and concen-
trated in vacuo. The residue was purified by flash column
chromatography on silica gel with EtOAc/hexanes (1:1) as
eluant to afford 53-59 as colorless oils in 80-92% yield.
1-H yd r oxym et h yl-3,14-d ioxa b icyclo[10.2.1]p en t a d ec-
1
11(E)-en e-4,13-d ion e (53): H NMR (CDCl3) δ 6.58 (m, 1 H,
>CdCH), 4.92 (d, 1 H, J ) 12.2 Hz, OCOCH2), 3.90 (d, 1 H, J
) 12.2 Hz, OCOCH2), 3.75 (AB q, 2 H, J ) 12.5 Hz, CH2OH),
2.70 (m, 2 H, H-4), 2.30 (t, 2 H, J ) 7.5 Hz, CH2CO2), 2.15 (m,
2 H, >CdCH-CH2), 1.25-1.7 (m, 8 H, (CH2)4); IR (neat) 3445,
1732, 1682 cm-1; MS (FAB) m/z 269 (MH+). Anal. (C14H20O5)
C, H.
Gen er a l P r oced u r e for th e Syn th esis of 46-52. To a
stirred suspension of 4-(dimethylamino)pyridine (183 mg, 1.5
mmol), 4-(dimethylamino)pyridine hydrochloride (237 mg, 1.5
mmol), and dicyclohexylcarbodiimide (1 M, 1.5 mL, 1.5 mmol)
in refluxing CH2Cl2 (30 mL) was added dropwise a solution of
39-45 (0.3 mmol) in CH2Cl2 (5 mL) via syringe pump. After
being refluxed for 16 h, the reaction mixture was cooled and
quenched with methanol (2 mL) and acetic acid (0.2 mL). The
1-H yd r oxym et h yl-3,18-d ioxa b icyclo[14.2.1]n on a d ec-
1
15(E)-en e-4,17-d ion e (54): H NMR (CDCl3) δ 6.78 (m, 1 H,
>CdCH), 4.22 (AB q, 2 H, J ) 11.8 Hz, OCOCH2), 3.72 (AB q,

DAG-bis-lactones
J ournal of Medicinal Chemistry, 2004, Vol. 47, No. 16 4007
2 H, J ) 12.4 Hz, CH2OH), 2.79 (m, 2 H, H-4), 2.31 (t, 2 H, J
) 7.5 Hz, CH2CO2), 2.15 (m, 2 H, >CdCH-CH2), 1.25-1.7
(m, 16 H, (CH2)8); IR (neat) 3441, 1743, 1679 cm-1; MS (FAB)
m/z 325 (MH+). Anal. (C18H28O5) C, H.
Refer en ces
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(2) Protein Kinase C; Kuo, J . F., Ed.; Oxford University Press: New
York, 1994.
1-H yd r oxym et h yl-3,18-d ioxa b icyclo[14.2.1]n on a d ec-
1
15(Z)-en e-4,17-d ion e (55): H NMR (CDCl3) δ 6.24 (m, 1 H,
(3) Nishizuka, Y. Intracellular Signalling by Hydrolysis of Phos-
pholipids and Activation of Protein Kinase C. Science 1992, 258,
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>CdCH), 4.24 (dt, 2 H, J ) 11.9 Hz, OCOCH2), 3.67 (m, 2 H,
CH2OH), 3.08 (m, 1 H, >CdCH-CH2), 2.82 (m, 2 H, H-4),
2.25-2.45 (m, 3 H, CH2CO2 and >CdCH-CH2), 1.2-1.7 (m,
16 H, (CH2)8); IR (neat) 3443, 1746, 1679 cm-1; MS (FAB) m/z
325 (MH+). Anal. (C18H28O5) C, H.
(4) Newton, A. C. Protein Kinase C: Structural and Spatial Regula-
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1-Hyd r oxym eth yl-3,22-d ioxa bicyclo[18.2.1]tr ieicos-19-
(E)-en e-4,21-d ion e (56): 1H NMR (CDCl3) δ 6.76 (m, 1 H,
>CdCH), 4.24 (AB q, 2 H, J ) 11.8 Hz, OCOCH2), 3.70 (AB q,
2 H, J ) 12.2 Hz, CH2OH), 2.76 (m, 2 H, H-4), 2.31 (t, 2 H, J
) 7.5 Hz, CH2CO2), 2.15 (m, 2 H, >CdCH-CH2), 1.25-1.7
(m, 24 H, (CH2)12); IR (neat) 3445, 1747, 1683 cm-1; MS (FAB)
m/z 381 (MH+). Anal. (C22H36O5) C, H.
(6) Newton, A. C. Regulation of Protein Kinase C. Curr. Opin. Cell
Biol. 1997, 9, 161-167.
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(8) Sharkey, N. A.; Leach, K. L.; Blumberg, P. M. Competitive
Inhibition by Diacylglycerol of Specific Phorbol Ester Binding.
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1-Hyd r oxym eth yl-3,22-d ioxa bicyclo[18.2.1]tr ieicos-19-
(Z)-en e-4,21-d ion e (57): 1H NMR (CDCl3) δ 6.24 (m, 1 H,
>CdCH), 4.24 (dt, 2 H, J ) 11.9 Hz, OCOCH2), 3.67 (m, 2 H,
CH2OH), 3.08 (m, 1 H, >CdCH-CH2), 2.82 (m, 2 H, H-4),
2.25-2.45 (m, 3 H, CH2CO2 and >CdCH-CH2), 1.2-1.7 (m,
24 H, (CH2)12); IR (neat) 3445, 1748, 1683 cm-1; MS (FAB) m/z
381 (MH+). Anal. (C22H36O5) C, H.
(9) Marquez, V. E.; Nacro, K.; Benzaria, S.; Lee, J .; Sharma, R.;
Teng, K.; Milne, G. W. A.; Bienfait, B.; Wang, S.; Lewin, N. E.;
Blumberg, P. M. The Transition from a Pharmacophore-Guided
Approach to a Receptor-Guided Approach in the Design of Potent
Protein Kinase C Ligands. Pharmacol. Ther. 1999, 82, 251-261.
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and DAG-Lactones as Activators of Protein Kinase C (PK-C).
Acc. Chem. Res. 2003, 36, 434-443.
1-Hyd r oxym eth yl-3,26-d ioxa bicyclo[22.2.1]h ep ta eicos-
(11) Sharma, R.; Lee, J .; Wang, S.; Milne, G. W. A.; Lewin, N. E.;
Blumberg, P. M.; Marquez, V. E. Conformationally Constrained
Analogues of Diacylglycerol (DAG). 10. Ultrapotent Protein
Kinase C (PK-C) Ligands Based on a Racemic 5-Disubstituted
Tetrahydro-2-furanone Template. J . Med. Chem. 1996, 39, 19-
28.
(12) Lee, J .; Wang, S.; Milne, G. W. A.; Sharma, R.; Lewin, N. E.;
Blumberg, P. M.; Marquez, V. E. Conformationally Constrained
Analogues of Diacylglycerol. 11. Ultrapotent Protein Kinase C
Ligands Based on a Chiral 5-Disubstituted Tetrahydro-2-fura-
none Template. J . Med. Chem. 1996, 39, 29-35.
(13) Zhang, G. G.; Kazanietz, M. G.; Blumberg, P. M.; Hurley, J . H.
Crystal Structure of the Cys2 Activator-Binding Domain of
Protein Kinase C Delta in Complex with Phorbol Ester. Cell
1995, 81, 917-924.
(14) Nacro, K.; Bienfait, B.; Lee, J .; Han, K.-C.; Kang, J .-H.; Benzaria,
S.; Lewin, N. E.; Bhattacharyya, D. K.; Blumberg, P. M.
Conformationally Constrained Analogues of Diacylglycerol (DAG).
16. How Much Structural Complexity Is Necessary for Recogni-
tion and High Binding Affinity to Protein Kinase C? J . Med.
Chem. 2000, 43, 921-944.
(15) Lee, J .; Han, K.-C.; Kang, J .-H.; Pearce, L. L.; Lewin, N. E.; Yan,
S.; Benzaria, S.; Nicklaus, M. C.; Blumberg, P. M.; Marquez, V.
E. Conformationally Constrained Analogues of Diacylglycerol.
18. The Incorporation of a Hydroxamate Moiety into DAG-
Lactones Reduces Lipophilicity and Helps Discriminate between
Sn-1 and Sn-2 Binding Modes to Protein Kinase C (PK-C),
Implications for Isozyme Specificity. J . Med. Chem. 2001, 44,
4309-4312 (published erratum appears in J . Med. Chem. 2003,
46, 2794).
(16) Meylan, W. M.; Howard, P. H. Atom Fragment Contribution
Method for Estimating Octanol-Water Partition Coefficients.
KOWWIN 1.63 Syracuse Research Corp.; http://esc.syrres.com.
J . Pharm. Sci. 1995, 84, 83-92.
(17) Lee, J . Design and Synthesis of Bioisosteres of Ultrapotent
Protein Kinase C (PKC) Ligand, 5-Acetoxymethyl-5-Hydroxy-
methyl-3-Alkylidene Tetrahydro-2-furanone. Arch. Pharmacal
Res. 1998, 452-457.
(18) Keck, G. E.; Boden, E. P. Proton-Transfer Steps in Steglich
Esterification: A Very Practical New Method for Macrolacton-
ization. J . Org. Chem. 1985, 50, 2394.
1
23(E)-en e-4,25-d ion e (58): H NMR (CDCl3) δ 6.76 (m, 1 H,
>CdCH), 4.24 (AB q, 2 H, J ) 11.8 Hz, OCOCH2), 3.70 (AB q,
2 H, J ) 12.2 Hz, CH2OH), 2.75 (m, 2 H, H-4), 2.32 (t, 2 H, J
) 7.5 Hz, CH2CO2), 2.17 (m, 2 H, >CdCH-CH2), 1.25-1.7
(m, 32 H, (CH2)16); IR (neat) 3446, 1741, 1683 cm-1; MS m/z
437 (MH+). Anal. (C26H44O5) C, H.
1-Hyd r oxym eth yl-3,26-d ioxa bicyclo[22.2.1]h ep ta eicos-
1
23(Z)-en e-4,25-d ion e (59): H NMR (CDCl3) δ 6.23 (m, 1 H,
>CdCH), 4.22 (AB q, 2 H, J ) 12 Hz, OCOCH2), 3.66 (AB q,
2 H, J ) 11.8 Hz, CH2OH), 3.08 (m, 1 H, >CdCH-CH2), 2.82
(m, 2 H, H-4), 2.53 (m, 1 H, >CdCH-CH2), 2.29 (m, 3 H, J )
7.3 Hz, CH2CO2), 1.2-1.7 (m, 32 H, (CH2)16); IR (neat) 3446,
1741, 1683 cm-1; MS (FAB) m/z 437 (MH+). Anal. (C26H44O5)
C, H.
Molecu la r Mod elin g. The structures of compounds 6 and
57 were built using the Sybyl molecular modeling program
(Tripos, Inc.), and then the geometry was fully optimized using
the Tripos force field with the following nondefault options:
(method) conjugate gradient; (termination) gradient 0.01 kcal
mol-1 Å-1; (max iterations) 10,000. The partial atomic charges
were calculated by the Gasteiger-Hu¨ckel method in the Sybyl
program. The theoretical structure of the C1b domain of PKCR,
which was constructed through homology modeling by Mar-
quez and colleagues,19 was used in the docking study. Only
polar hydrogens were added, and then the Kollman united-
atom partial atomic charges were assigned to the macromol-
ecule. Each compound was docked into the C1b domain of
PKCR using the program Autodock 3.0 with 100 genetic
algorithm (GA) runs. The long alkyl chain (-C13H27) of
compound 6 was shortened to three methylene groups (-C3H7)
in order to reduced the number of degrees of freedom during
docking simulation. The torsions of each compound were
defined to fully consider conformational flexibility while the
C1b domain of PKCR remained rigid. All computational work
(19) Sigano, D. M.; Peach, M. L.; Nacro, K.; Choi, Y.; Lewin, N. E.;
Nicklaus, M. C.; Blumberg, P. M.; Marquez, V. E. Differential
Binding Modes of Diacylglycerol (DAG) and DAG Lactones to
Protein Kinase C (PK-C). J . Med. Chem. 2003, 46, 1571-1579.
(20) Morris, G. M.; Goodsell, D. S.; Halliday, R. S.; Huey, R.; Hart,
W. E.; Belew, R. K.; Olson, A. J . Automated Docking Using a
Lamarckian Genetic Algorithm and an Empirical Binding Free
Energy Function. J . Comput. Chem. 1998, 19, 1639-1662.
(21) Wang, Q. J .; Fang, T.-W.; Nacro, K.; Marquez, V. E.; Wang, S.;
Blumberg, P. M. Role of Hydrophobic Residues in the C1b
Domain of Protein Kinase C δ on Ligand and Phospholipid
Interactions. J . Biol. Chem. 2001, 276, 19580-19587.
was done on
tion.
a Silicon Graphics O2 R10000 worksta-
Ack n ow led gm en t. This work was supported by
Korea Research Foundation Grant KRF-2003-015-
E00229.
Su p p or tin g In for m a tion Ava ila ble: Elemental analysis
data for final compounds. This material is available free of
charge via the Internet at http://pubs.acs.org.
J M0497747