α-Cycloalkyl-substituted ω-keto-dicarboxylic acids as lipid regulating agents

Article abstract of DOI:10.1016/j.bmc.2004.09.046

A series of cycloalkyl-substituted oxo-alkanedicarboxylic acids have been prepared by the TosMIC methodology departing from haloalkyl-substituted cycloalkylcarboxylic esters. cyclopropyl derivatives showed IC₅₀ activity in the 0.3-1.0 μM range

Full text of DOI:10.1016/j.bmc.2004.09.046

Bioorganic & Medicinal Chemistry 13 (2005) 223–236
a-Cycloalkyl-substituted x-keto-dicarboxylic acids as
lipid regulating agents
Roel P. L. Bell,a Dennis Verdijk,a Mike Relou,a Dennis Smith,a Henk Regeling,a
Eelco J. Ebbers,a Frank M. C. Leemhuis,a Daniela C. Oniciu,b,* Clay T. Cramer,b
Brian Goetz,b Michael E. Pape,b Brian R. Krauseb and Jean-Louis Dasseuxb
aMercaChem BV, Toernooiveld 100, 6525 EC Nijmegen, The Netherlands
bEsperion Therapeutics a Division of Pfizer Global Research and Development, 3621 S. State Street, 695 KMS Place,
Ann Arbor, MI 48108, USA
Received 20 January 2004; accepted 23 September 2004
Abstract—A series of cycloalkyl-substituted oxo-alkanedicarboxylic acids have been prepared by the TosMIC methodology depart-
ing from haloalkyl-substituted cycloalkylcarboxylic esters. cyclopropyl derivatives showed IC50 activity in the 0.3–1.0lM range on
the de novo incorporation of radiolabeled acetate into lipids in primary cultures of rat hepatocytes, and they showed lipid-regulating
properties when tested in vivo in female obese Zucker fatty rats.
ꢀ 2004 Elsevier Ltd. All rights reserved.
1. Introduction
assays for the tetramethyl substituted keto-diacids and
-diols, and the least active were shown to be the bis-
(aryl–methyl) derivatives.2 In vitro activities in these
series were found to be at the micromolar level. We
now report the synthesis of a series of cycloalkyl-substi-
tuted oxo-alkanedicarboxylic acids, some of which
possess submicromolar activity in vitro and exhibit more
marked alterations in plasma lipids/lipoproteins.
We recently identified several functionalized long chain-
hydrocarbon derivatives as possessing lipid-regulating
activity in an animal model of diabetic dyslipidemia
(i.e., obese female Zucker fatty rat).1,2 This pharmaco-
logic activity consisted of plasma triglyceride reduction,
decreases in non-HDL-cholesterol (non-HDL-C), and
increases in HDL-cholesterol (HDL-C). Unlike HMG-
CoA reductase inhibitors (statins), these compounds
inhibit both fatty acid and cholesterol syntheses in cul-
tured liver cells at micromolar concentrations, and also
increase fatty acid oxidation. In this way they reduce the
availability of lipids for triglyceride synthesis and very
low density lipoprotein (VLDL) assembly. Our earlier
work was focused on the design of long hydrocarbon
chain ether- and keto-diols and -diacids with gem-
dialkyl and alkyl/aryl substitution to the terminal acid
or methylenehydroxy functions.1,2 The most active com-
pounds reported displayed symmetrical structures with
four to five methylene groups separating central ether
and ketone functionalities and the gem-dimethyl or
methyl/aryl substituents. Furthermore, biological activ-
ity was found to be greatest in both in vivo and in vitro
2. Biological data
Compounds were tested for inhibition of lipid synthesis
in primary cultures of rat hepatocytes using the radio-
labeled precursor [1-14C] acetate. Interestingly, the com-
pounds with symmetrical terminating cyclopentyl
substitutions varied by 50-fold in terms of in vitro activ-
ity, the only difference being chain length on either side
of the central ketone (Table 1). Thus, 7g (4,4-ketone)
was a weak inhibitor of lipid synthesis (113lM) com-
pared to 7m (2lM, 5,5-ketone). The symmetrical 4,4-
cyclobutyl derivative was also a weak inhibitor (7f).
The symmetrical cyclopropyl compounds were potent
regardless of chain length (7d, 7l), but not the corre-
sponding ester compounds (e.g., t-butyl ester 6d). In
fact, these two compounds (7d,l) were submicromolar
inhibitors of lipid synthesis in liver cells. The unsymmet-
rical cyclopropyl compounds (7c,k) retained potent
Keywords: Dyslipidemia; HDL-cholesterol; TosMic; Cycloalkyl.
*
Corresponding author. Tel.: +1 734 222 1825; fax: +1 734 332
0516; e-mail: Daniela.Oniciu@Pfizer.com
0968-0896/$ - see front matter ꢀ 2004 Elsevier Ltd. All rights reserved.
doi:10.1016/j.bmc.2004.09.046

224
R. P. L. Bell et al. / Bioorg. Med. Chem. 13 (2005) 223–236
Table 1. Effect of cycloalkyl compounds on lipid synthesis in primary rat hepatocytes
Compound
IC50 (lM)
95% Confidence
interval
r2a
Structure
Lower
Upper
NAb
0.39
HO
O
OH
7a
O
O
O
O
7b
7c
NAb
0.6
0.00
0.98
HO
OH
O
HO
O
OH
OH
0.3
0.1
5
0.9
5
O
O
O
HO
O
7d
7e
0.3
6
0.98
0.95
O
O
O
HO
O
OH
OH
OH
8
O
O
O
HO
O
7f
121
11
1268
1794
0.89
0.95
0.32
HO
7g
7h
113
7
O
O
O
O
O
OEt
EtO
NAb
HO
OH
O
O
O
O
O
OEt
EtO
6h
NAb
0.00
EtO
OEt
O
O
tBuO
OtBu
6d
7i
35
NAb
40
26
17
48
0.99
0.32
0.98
0.94
0.99
O
O
O
HO
OH
O
O
EtO
6j
92
O
O
HO
HO
OH
7k
7l
1
0.7
1.4
0.7
O
O
O
OH
OH
0.5
0.4
2
O
O
O
HO
HO
7m
2
10
13
43
2
21
46
64
0.99
0.97
0.93
0.99
O
O
O
O
OH
7n
4
O
O
O
EtO
OEt
6n
4
O
O
3-Thia fatty acid
28
S
OH
a r2 is the goodness of fit of the data to the non-linear sigmoidal model.
b No IC50 is derived using the non-linear regression model. We have defined these compounds as ꢀnot activeꢁ.
in vitro activity. Alkyl compounds with various bulky
substituents other than cycloalkyl (7i, 6j, 7n, 6n) and
linear dicarboxylic acids 7a and 7b were all weak inhibi-
tors (i.e., P10lM).
To prove that the decreased incorporation of acetate
into lipids is not due to a general toxic effect, we used
a standard method for assessing compound effects on
plasma membrane integrity, which directly correlates

R. P. L. Bell et al. / Bioorg. Med. Chem. 13 (2005) 223–236
225
with cell viability in primary rat hepatocytes. Briefly, re-
lease of the cytosolic enzyme lactate dehydrogenase
(LDH) into the media compartment due to plasma
membrane damage is assessed by measuring LDH en-
zyme activity.3 Compound-dependent increases in the
activity in the media are compared to vehicle-treated
cultures. We tested all the active compounds, and the
test results indicate that toxicity does not correlate with
inhibition of [1-14C] acetate incorporation into lipids.
The compounds that caused increased LDH leakage
did so only at the 300lM treatment concentration and
the increases were minimal at 20–40% above control val-
ues (data not shown). A direct toxic agent tested in this
assay will produce 400–500% increases in LDH activity
in the media.
that were poorly active in vitro provided weak lipid-reg-
ulating activity in vivo (7h, 6h, 6j). Not all compounds
that lowered plasma triglycerides elevated HDL-C (7d
vs 7f). With the exception of compound 7d, we generally
see a good predictable relation between observations in
vitro and in vivo for reduction of non-HDL-C. In regard
to triglyceride lowering, we observed that all compounds
were active. The symmetrical 5,5-cyclopropyl compound
(7l) shows the best correlation of in vivo and in vitro
activities, and the highest HDL-C elevation, which is
in agreement with earlier findings in the gem-dimethyl
series, and shows enhanced properties compared to its
congeners in both the ether and ketone series.2
The mechanism of action is clearly a key component of
drug discovery. As we performed our structure optimi-
zation in vivo, multiple MoAs may be responsible for
the biological activity in such a complex biological sys-
tem as the whole animal. This phenomenon is not unu-
sual in compounds presenting HDL-elevating properties
in various animal models.4a We have performed multiple
experiments on this class of compounds (with terminal
Compounds with the greatest in vitro activity, <1lM
(7c,d,l) also produced the greatest elevations in HDL-
C in vivo (Table 2). Cyclopropyl substitutions, whether
symmetrical (7l) or unsymmetrical (7k), provided potent
and long-lasting reductions in non-HDL-C (>90%), but
only for 5,5-carbon length hydrocarbons. Compounds
Table 2. Effect of cycloalkyl compounds in female Obese Zucker rats
Compound
Serum variables (percent change from pre-treatment)a
Structure
Dose (mg/kg)
No animals
Non-HDL-
cholesterol
HDL-
cholesterol
TG
1wk
2wk
1wk
2wk
1wk
2wk
HO
O
OH
OH
7c
100
3
ꢀ84
ꢀ20
104
248
ꢀ93
ꢀ64
O
O
O
O
HO
O
7d
7e
100
100
3
4
22
4
63
28
180
30
260
60
ꢀ51
ꢀ54
ꢀ28
ꢀ51
HO
O
OH
OH
OH
O
O
O
O
O
O
HO
O
7f
100
100
4
4
ꢀ32
ꢀ68
ꢀ40
ꢀ67
ꢀ1
10
40
ꢀ58
ꢀ67
ꢀ59
ꢀ70
HO
7g
36
O
O
O
OEt
EtO
EtO
7h
6h
100
100
4
4
47
62
26
85
11
5
19
14
48
13
40
HO
OH
O
O
O
O
O
O
O
OEt
ꢀ1
EtO
EtO
HO
HO
OEt
O
O
6j
30
4
4
4
ꢀ11
ꢀ90
ꢀ92
57
ꢀ99
ꢀ83
54
43
95
84
ꢀ5
ꢀ93
ꢀ95
44
ꢀ98
ꢀ94
O
O
OH
OH
7k
7l
100
100
O
O
O
O
O
136
171
O
O
HO
HO
OH
7m
7n
100
100
4
3
ꢀ54
ꢀ80
ꢀ32
ꢀ45
12
44
27
86
ꢀ63
ꢀ85
ꢀ48
ꢀ64
O
O
O
OH
O
a 100% represents a 2-fold increase from pre-treatment value.

226
R. P. L. Bell et al. / Bioorg. Med. Chem. 13 (2005) 223–236
cycloalkyl and dimethyl substitution) and have deter-
mined that a major mode of action (within minutes of
dosing) is inhibition of fatty acid synthesis (FAS) at
the acetylCoA-carboxylase (ACC) step via an allosteric
mechanism. The inhibition of fatty acid synthesis pro-
duced by such a MoA is consistent with the lowering
of serum triglycerides. We have also shown that these
compounds rapidly block de novo cholesterol synthesis
at a step between acetoacetyl-CoA formation and
HMG-CoA.4b Thus, they are dual inhibitors of lipid
synthesis.
(68–78ꢂF; 30–75% RH) were monitored and the airflow
in the room was sufficient to provide several exchanges
per hour with 100% fresh filtered air. An automatic tim-
ing device provided an alternating 12h cycle of light and
dark. Rats received pelleted Purina Laboratory Rodent
Chowꢁ (5001) prior to and during the drug intervention
period except for a 6h phase prior to blood sampling.
Fresh water was supplied ad libitum via an automatic
watering system. Compounds were dissolved, suspended
by mixing in a dosing vehicle consisting of 20% ethanol
and 80% polyethylene glycol-200 [v/v]. Dose volume of
vehicle or vehicle plus each compound was set at
0.25% of body weight in order to deliver the appropriate
dose. Doses were administered daily by oral gavage,
approximately between 8 and 10 AM. Regarding blood
sampling, animals were fasted for 6h prior to all blood
collections. Prior to and after 7days of dosing, a 1.0–
2.0mL sample of blood was collected by administering
O2/CO2 anesthesia and bleeding from the orbital venous
plexus. Following 14days of dosing, blood was collected
by cardiac puncture after euthanasia with CO2. All
blood samples were processed for separation of serum
and stored at ꢀ80ꢂC until analysis. Commercially avail-
able kits were used to determine serum triglycerides
(Roche Diagnostic Corporation, Kit no 148899 or
Boehringer Mannheim, Kit no 1488872), total choles-
terol (Roche Diagnostic Corporation, Kit no 450061),
non-esterified fatty acids (Wako Chemicals, Kit no
994-75409), and b-hydroxybutyrate (Wako Chemicals,
Kit no 417-73501 or Sigma Kit no 310-0) on a Hitachi
912 Automatic Analyzer (Roche Diagnostic Corpora-
tion). In some instances, an in-house cholesterol reagent
was used to determine total serum cholesterol levels.
Serum lipoprotein cholesterol levels were determined
by lipoprotein profile analysis. Lipoprotein profiles were
analyzed using gel-filtration chromatography on a Supe-
rose 6HR (1 · 30cm) column equipped with on-line
detection of total cholesterol as described by Kieft
et al.6 The total cholesterol content of each lipoprotein
was calculated by multiplying the independent values
determined for serum total cholesterol by the percent
area of each lipoprotein in the profile.
3. Biological methods
3.1. In vitro measurement of lipid synthesis in isolated
hepatocytes
Compounds were tested for inhibition of lipid synthesis
in primary cultures of rat hepatocytes. Male Sprague–
Dawley rats were anesthetized with intraperitoneal
injection of sodium pentobarbital (80mg/kg). Rat
hepatocytes were isolated essentially as described by
the method of Seglen.5 Hepatocytes were suspended in
Dulbeccoꢁs Modified Eagles Medium containing
25mM D-glucose, 14mM HEPES, 5mM L-glutamine,
5mM leucine, 5mM alanine, 10mM lactate, 1mM
pyruvate, 0.2% bovine serum albumin, 17.4mM non-
essential amino acids, 20% fetal bovine serum, 100nM
insulin, and 20lg/mL gentamycin and plated at a
density of 1.5 · 105 cells/cm2 on collagen-coated 96-
well plates. Four hours after plating, media was replaced
with the same media without serum. Cells were grown
overnight to allow formation of monolayer cultures.
Lipid synthesis incubation conditions were initially
assessed to ensure the linearity of [1-14C]-acetate incor-
poration into hepatocyte lipids for up to 4h. Hepatocyte
lipid synthesis inhibitory activity was assessed during
incubations in the presence of 0.25lCi [1-14C]-acetate/
well (final radiospecific activity in assay is 1Ci/mol)
and 0, 1, 3, 10, 30, 100, or 300lM of compounds for
4h. At the end of the 4h incubation period, medium
was discarded and cells were washed twice with ice-
cold phosphate buffered saline and stored frozen prior
to analysis. To determine total lipid synthesis, 170lL
of MicroScint-Eꢁ and 50lL water was added to each
well to extract and partition the lipid soluble products
to the upper organic phase containing the scintillant.
Lipid radioactivity was assessed by scintillation spectros-
copy in a Packard TopCount NXT. Lipid synthesis
rates were used to determine the IC50s of the
compounds.
4. Chemistry
A series of long hydrocarbon chain keto-diacids (7a–h,
7k–n)7 was prepared. Characteristic for all of these mole-
cules is the central ketone moiety connected via two lin-
ear carbon spacers to the terminating acids, which differ
in their pattern of a-substitution. The key step in the
syntheses of most of these ketones is the alkylation of
the formaldehyde synthon: tosylmethyl isocyanide (Tos-
MIC)8 with
a properly functionalized halo-ester
(Scheme 1). Keto-diol 7i was included in this study as
well.
3.2. In vivo effects on lipid variables in female obese
Zucker fatty rats
Ten- to twelve-week old (400–500g) female Zucker fatty
rats Crl: (Zuc)-faBR were obtained from Charles River
Laboratories. Animals were acclimated to the labora-
tory environment for 7days. During the acclimation
and study period, animals were housed by group in
shoebox polycarbonate cages on Cellu-Dri bedding.
The temperature and humidity in the animalsꢁ quarters
The halo-esters were prepared via alkylation of commer-
cially available or known esters (1) with a dihaloalkane
(2) of proper length (Scheme 2, Table 3). It was planned
to use the ethyl ester analogues of 1 as starting material,
but since it is known that ethyl cyclopropylcarboxylate
is prone to self-condensate on treatment with various

R. P. L. Bell et al. / Bioorg. Med. Chem. 13 (2005) 223–236
227
C
O
m
R1 R2
R2 R1
R1 R2
O
a or b
O
m
p
OH
N+
O
O
X
m
O
p
HO
p
O
R
R
R
O
S
m
O
+
X
m
R
O
m
O
O
O
O
O
O
6d,f-h,l-n
7d,f-h,l-n: R=H
3b-c,e
5b-e
c
7d,f-g,l-m
TosMIC
p = 1-3
Scheme 3. Symmetrical ketones. Reagents and conditions: (a)
6d,g,h,m,n: Method A:11 (1) NaH, TosMIC, Bu4NI, DMSO, rt, (2)
HCl (concd), CH2Cl2, rt; (b) 6f,l: Method B:11 (1) KOtBu, TosMIC,
DMAc, 0ꢂC–rt, (2) HCl (concd), CH2Cl2, rt; (c) 6d,l: Method E:11
HCO2H, rt, 6f,g,m,n: Method D:11 LiOH, EtOH/H2O, D, 6h: KOH,
EtOH/H2O, rt.
C
N+
O
p
OH
O
S
HO
O
m
n
m
O
O
7c,e,k
8a,b
Scheme 1.
(3a–e) were treated with a catalytic amount of Bu4NI
to form the corresponding iodo compounds in situ.
Initially, for the alkylation of TosMIC, Method A11
(TosMIC, NaH, 3, Bu4NI in DMSO) was applied
(Scheme 3). The intermediate dialkylated TosMIC
derivatives were treated with concd HCl in CH2Cl2 to
provide keto-diesters 6d,h,n in moderate to good yield
(Table 4). For the preparation of symmetrical keto-
diacids 6f,g,l,m a modified procedure (Method B:11
KOtBu, 5 in N,N-dimethylacetamide (DMAc)) was used
(Table 4). On applying this method, side product forma-
tion was significantly suppressed.
R1
R1 R2
O
3a-e: X=Br
4a-e: X=Cl
5a-e: X=I
a
O
O
X
m
Br
X
+
R
R2
R
m
O
1
2
b
Scheme 2. Reagents and condition: (a) LDA, THF, ꢀ60ꢂC to rt; (b)
NaI, 2-butanone, D.
Table 3. Synthesis of halo-esters 3a–e, 4a–e, and 5a–e
A set of mono-alkylated TosMIC derivatives (8a,b) was
desired for the preparation of unsymmetrical ketones
6c,e,j,k (Scheme 4). As such intermediates could only
be produced in low yield via Method A, more selective
conditions (K2CO3, DMAc) were applied, providing
8a,b in good yield. Subsequent treatment of 8a,b as
reported for Method C11 (KOtBu, 5, DMAc) afforded
the unsymmetrical ketones 6c,e,k (Scheme 4, Table 4).
Unsymmetrical ketone 6j was prepared, starting from
8b and 2-bromoethylbenzene, via method A (Scheme
4, Table 4).
Compound
m
R
R1
R2
X
Yield (%)
a
3a
3b
3c
3d
3e
4a
4b
4c
4d
4e
5a
5b
5c
5d
5e
4
4
4
5
7
4
4
4
5
5
4
4
4
5
5
Et
Me
Me
Br
Br
Br
Br
Br
Cl
Cl
Cl
Cl
Cl
I
tBu
Et
cyclopropyl
34b
c
CO2Et
Me
Me
Me
Me
Me
d
Et
Et
45
52
tBu
Et
cyclopropyl
cyclobutyl
cyclopentyl
cyclopropyl
cyclopentyl
cyclopropyl
cyclobutyl
cyclopentyl
cyclopropyl
cyclopentyl
86
86
Et
tBu
Et
73
90
tBu
Et
94b
99
The target keto-diacids (7) were prepared from the cor-
responding ester analogues (6) by saponification of the
appropriate ethyl esters, treatment of t-butyl esters with
HCO2H, or a combination of the two (Schemes 3 and 4
Table 4).
I
Et
I
94b
99
tBu
Et
I
I
93b
a See: Ref. 18.
b Purity >90%.
c See: Ref. 20.
d See: Ref. 1.
Further, the known compounds 7a12 and 7b13 were pre-
pared as depicted in Scheme 5 and 6, respectively. Subse-
quent treatment of 7b with trimethyl orthoformate under
acidic conditions provided the symmetrical acetal-diester
15, which on treatment with MeMgCl and acidic workup
afforded keto-diol 7i in good yield (Scheme 6).14
bases,9 the corresponding t-butyl analogue, of which a
couple of successful alkylations are reported,10 was pre-
pared. At first, the bromo-esters 3a–e were prepared via
treatment of 1 with LDA and a large excess of a di-
bromoalkane (2, X = Br). However, due to substantial
amount of dialkylation products, a more selective alkyl-
ating agent: bromo-chloroalkane (2, X = Cl) was used.
As another advantage, it turned out that the crude prod-
uct (4) was easier to separate from excess of 2 (X = Cl)
via fractional distillation, when compared to crude 3
and 2 (X = Br). Compound 3d was prepared as de-
scribed earlier.1 Where the chloro-ester derivatives (4a–
e) were converted to the corresponding iodides (5a–e)
prior to their reaction with TosMIC, bromo-esters
5. Conclusion
In summary, we have identified micromolar inhibitors
in vitro of both fatty acid and cholesterol biosynthesis
among a group of cyclopropyl derivatives. The most
potent compounds 7c,d,l markedly elevate HDL-choles-
terol, and also significantly reduce plasma triglycerides
and non-HDL-cholesterol levels (7c,l) in a rodent model
of dyslipidemia. Amongst them, compound 7l is the
most promising lipid regulating agent, producing the

228
R. P. L. Bell et al. / Bioorg. Med. Chem. 13 (2005) 223–236
Table 4. Syntheses of keto-esters (6) and corresponding keto-acids (7) using TosMIC chemistry
Compound 6
Compound 7
6
Structure
Methoda Yield (%)
6!7
Elemental analysis found (calculated)
Methoda Yield (%)
C
H
Mp (ꢂC)
EtO
O
OtBu
c
d
e
C
A
C
43b
49
F
E
D
80b
99
65.06 (65.36) 9.02 (9.03)
65.40 (65.78) 8.37 (8.44)
66.26 (66.23) 9.37 (9.26)
49–52
O
O
tBuO
O
OtBu
132–134
53–55
O
O
75b
76
EtO
O
OEt
OEt
OEt
O
O
O
O
O
O
EtO
O
f
B
B
82
D
D
c
56
67.19 (67.43) 8.97 (8.93)
68.78 (68.82) 9.47 (9.35)
69–70
g
83b
99b
104–106
EtO
O
O
O
OEt
EtO
h
A
71
81
—
—
—
—
—
EtO
EtO
EtO
OEt
O
O
O
O
O
j
A
C
B
B
A
68
—
F
—
84
99
91
74
—
O
57b
46b
87b
57
66.86 (67.03) 9.50 (9.47)
67.20 (67.43) 9.05 (8.93)
70.37 (70.02) 9.72 (9.71)
65–66
122–123
78–85
OtBu
k
l
O
O
O
tBuO
OtBu
E
O
O
O
EtO
EtO
OEt
m
n
D
D
O
O
O
OEt
69.41 (69.31) 10.73 (10.62) 74–77
O
O
a See Ref. 11.
b Purity >90%.
c KOH, EtOH, rt.
O
C
EtO
OEt
b
N+
p
O
+
X
MeO
O
S
O
O
12
O
EtO
Br
m
I
n
EtO
a
R1
+
p
11: X=I
10: X=Br
m
O
a
O
O
O
5a-b,d
3a,d
8a-b
HO
OH
O
m
O
O
O
7a
b
O
O
R1
R
n
O
O
Scheme 5. Reagents and conditions: (a) NaI, acetone, rt, 95%; (b) (1)
NaOEt, 90ꢂC, (2) HCl (concd), H2O, D, 44%.
6c,e,k: R=Et
7c,e,k: R=R1=H
c
O
most favorable lipoprotein profile of the compounds
tested in this report.
d
EtO
O
8b
+
m
Br
9
6j
6. Experimental section
6.1. General
Scheme 4. Asymmetrical ketones. Reagents and conditions: (a)
K2CO3, Bu4NI, DMF, rt, 8a (m = 4) 67%, 8b (m = 5) 61%; (b) Method
C:11 (1) KOtBu, TosMIC, DMAc, 0ꢂC–rt, (2) HCl (concd), CH2Cl2,
rt; (c) 6c,k: Method F:11 (1) HCO2H, rt, (2) NaOH, EtOH/H2O, D, 6e:
Method D:11 LiOH, EtOH/H2O, D; (d) Method A:11 (1) NaH,
TosMIC, Bu4NI, DMSO, rt, (2) HCl (concd), CH2Cl2, rt, 68%.
All reagents and solvents were purchased from commer-
cial suppliers and used without prior treatment unless

R. P. L. Bell et al. / Bioorg. Med. Chem. 13 (2005) 223–236
229
O
N
6.1.1. t-Butyl 1-(4-bromobutyl)-cyclopropanecarboxylate
(3b). Under a N2 atmosphere at ꢀ60ꢂC, a solution of t-
butyl cyclopropanecarboxylate15 (80.05g, 0.507mol)
and 1,4-dibromobutane (219.3g, 1.01mol) in dry THF
(800mL) was added drop wise to a solution of LDA
(2M in THF/heptane/ethylbenzene, 380mL, 0.76mol)
in 1.5h. Stirring was continued for 5h, during which
the reaction mixture was allowed to slowly reach rt.
After that, the reaction mixture was poured into
saturated aqueous NH4Cl (1L). The organic layer was
separated and concentrated in vacuo to a smaller
volume. The aqueous layer was extracted with Et2O
(3 · 200mL). The combined organic layers were washed
with saturated aqueous NH4Cl (2 · 400mL) and brine
(400mL) and dried. The remaining residue was purified
by fractional distillation under reduced pressure to give
3b (51.4g, 94% pure by GC, 34%) as a slightly yellow oil.
Bp: T = 93–96ꢂC (p = 0.075–0.087Torr). 1H NMR: d
3.40 (t, J = 6.8Hz, 2H), 1.85 (quintet, J = 7.1Hz, 2H),
1.65–1.46 (m, 4H), 1.43 (s, 9H), 1.12 (q, J = 3.5Hz,
2H), 0.60 (q, J = 3.5Hz, 2H). 13C NMR: d 174.0, 79.8,
33.6, 33.2, 32.8, 27.9 (3·), 26.3, 23.9, 15.1 (2·). HRMS
calcd for C12H21BrO2 (MH+): 277.0803, found:
277.0807.
O
Cl
a
OMe
+
O
13
14
O
O
b
HO
OH
O
O
7b
O
O
c
O
O
O
15
HO
OH
O
7i
Scheme 6. Reagents and conditions: (a) (1) Et3N, D, (2) 1M HCl, D,
(3) 17M KOH, 100ꢂC, 69%; (b) CH(OMe)3, TsOH, MeOH, D, 85%;
(c) (1) MeMgCl, Et2O/THF, 0ꢂC–rt, (2) 1M HCl, rt, 93%.
stated otherwise. All product solutions were dried over
Na2SO4 prior to evaporation of the solvent under
reduced pressure by using a rotary evaporator. Column
chromatography was performed with silica gel (Fluka:
silica gel 60 with particle size 70–230 mesh or Acros: sil-
ica gel with particle size 0.060–0.200mm). Reactions
were monitored by GC or TLC on Macherey-Nagel
Polygramꢁ SIL G/UV254 plastic sheets. Compounds
on TLC were visualized by UV detection and/or dipping
in p-anisaldehyde/H2SO4/EtOH = 1:1:19 or basic
KMnO4 and subsequent heating. GC analysis was per-
formed on a Hewlett Packard 5890A gas chromato-
graph with a flame ionization detector and an Alltech
EC1 fused silica capillary column, 30m · 0.32mm inter-
nal diameter, film thickness 0.25lm and N2 as carried
gas. GC peak areas were integrated electronically with
a Hewlett Packard HP3396 seriesII integrator. LC/MS
analysis was performed on a Shimadzu QP8000a with
DAD (210–370gm)/MSD (100–600D) detection and
an Alltech Prefail C18, 50 · 4.6mm internal diameter,
film thickness 3lm column with 10mM HCO2H in
CH3CN/10mM HCO2H in H2O as elutes or a Agilent
1100-SL with ELSD/DAD (220–320gm)/MSD (100–
800D) detection and a Zorbaxꢁ SB-C18, 150mm ·
4.6mm internal diameter, film thickness 3.5lm column
with CH3CN/10mM HCO2H in H2O as elutes or a
Zorbaxꢁ Extend-C18, 150mm · 4.6mm internal
diameter, film thickness 3.5lm column with CH3CN/
10mM NH3 in H2O as elutes, flow = 1mL/min and col-
umn temperature = 35ꢂC. All 1H and 13C NMR spectra
were recorded on a Bruker AC-300 spectrometer in
CDCl3 unless otherwise stated. Chemical shifts are
reported in parts per million (d) relative to Me4Si.
HRMS data were obtained with a VG Micromass
VG7070E, Finnigan MAT95Q or Finnigan MAT900S
spectrometer. Elemental analysis were carried out on
a Carlo Erba Instruments CHNSO EA 1108 element
6.1.2. Ethyl 2,2-dimethyl-9-bromononanoate (3e). Under
a N2 atmosphere at 0ꢂC, LDA (2M in THF/heptane/
ethylbenzene, 13.0mL, 26.0mmol) was added drop wise
to a mixture of ethyl iso-butyrate (3.5mL, 25.9mmol)
and 1,7-dibromoheptane (9.84g, 38.2mmol) in dry
THF (50mL) in 1.5h, while keeping the temperature
below 5ꢂC. After 3h, the mixture was poured into ice-
cold saturated aqueous NH4Cl (150mL). The layers
were separated and the aqueous phase was extracted
with Et2O (3 · 100mL). The combined organic layers
were washed with aqueous HCl (1M, 100mL), saturated
aqueous NaHCO3 (100mL), and brine (100mL) and
dried. The remaining residue was purified by column
chromatography (heptane/EtOAc = 40:1) twice to give
1
3e (3.42g, 45%) as a colorless liquid. H NMR: d 4.11
(q, J = 7.2Hz, 2H), 3.40 (t, J = 6.9Hz, 2H), 1.85 (quin-
tet, J = 6.9Hz, 2H), 1.52–1.47 (m, 2H), 1.45–1.36 (m,
2H), 1.35–1.20 (m, 6H), 1.24 (t, J = 7.2Hz, 3H), 1.15
(s, 6H). 13C NMR: d 177.8, 60.0, 42.0, 40.5, 33.7, 32.7,
29.7, 28.5, 28.0, 25.0 (2·), 24.7, 14.1. HRMS calcd for
C13H25BrO2 (M+): 292.1038, found: 292.1034.
6.1.3. t-Butyl 1-(4-chlorobutyl)-1-cyclopropanecarboxyl-
ate (4a). Compound 4a was prepared, likewise the pro-
cedure described for 3b, starting from t-butyl
cyclopropanecarboxylate15 (12.5g, 88mmol), 1-bromo-
4-chlorobutane (13.7mL, 117mmol), and LDA (pre-
pared from BuLi (2.5M in hexanes, 37mL, 92.5mmol)
and iPr2NH (12.3mL, 88mmol, distilled from NaOH))
to give, after purification by fractional distillation under
reduced pressure, 4a (10.73g 52%) as a colorless oil. Bp:
T = 57–61ꢂC (p = 0.001mbar). 1H NMR: d 3.52 (t,
J = 6.6Hz, 2H), 1.76 (quintet, J = 6.8Hz, 2H), 1.64–
1.54 (m, 2H), 1.51–1.46 (m, 2H), 1.42 (s, 9H), 1.12
(dd, J = 6.6, 3.9Hz, 2H), 0.60 (dd, J = 6.6, 3.9Hz,
2H). 13C NMR: d 173.9, 80.0, 45.1, 33.6, 32.9, 28.2
(3·), 25.3, 24.2, 15.4 (2·). HRMS calcd for C12H22ClO2
(MH+): 233.1308, found: 233.1308.
analyzer. Melting points were measured on a Buchi
¨
Melting Point B-540 and are uncorrected. All pre-
pared compounds were >95% pure unless otherwise
stated.

230
R. P. L. Bell et al. / Bioorg. Med. Chem. 13 (2005) 223–236
6.1.4. Ethyl 1-(4-chlorobutyl)-1-cyclobutanecarboxylate
(4b). Compound 4b was prepared, likewise the proce-
dure described for 4d, starting from LDA (prepared
from BuLi (2.5M in hexanes, 52.8mL, 132mmol) and
iPr2NH (18.52mL, 132mmol, distilled from NaOH)),
ethyl 1-cyclobutanecarboxylate16 (14.05g, 110mmol,
the resultant mixture was allowed to warm to 0ꢂC and
cooled again to ꢀ60ꢂC) and 1-bromo-4-chlorobutane
(19.1mL, 165mmol) to give, after purification by frac-
tional distillation under reduced pressure, 4b (20.53g,
HRMS calcd for C13H24ClO2 (MH+): 247.1465, found:
247.1465.
6.1.7. Ethyl 1-(5-chloropentyl)-1-cyclopentanecarboxy-
late (4e). Compound 4e was prepared, likewise the pro-
cedure described for 4d, starting from LDA (prepared
from BuLi (2.5M in hexanes, 48.0mL, 120mmol) and
iPr2NH (17.0mL, 121mmol, distilled from NaOH)),
ethyl 1-cyclopentanecarboxylate17 (15.12g, 95% pure
1
by
H NMR, 101mmol, the resultant mixture was
86%) as
a
thin, colorless oil. Bp: T = 64–71ꢂC
kept below ꢀ50ꢂC) and 1-bromo-5-chloropentane
(25.53g, 135mmol, the resultant mixture was allowed
to warm to rt and stirred for 18h) to give, after purifica-
tion by fractional distillation under reduced pressure, 4e
(22.34g, 90%) as a thin, slightly yellow oil. Bp: T = 78–
82ꢂC (p = 0.001Torr). 1H NMR: d 4.11 (q, J =
7.1Hz, 2H), 3.50 (t, J = 6.8Hz, 2H), 2.14–2.06 (m,
2H), 1.75 (quintet, J = 7.1Hz, 2H), 1.66–1.57 (m, 6H),
1.48–1.35 (m, 4H), 1.28–1.19 (m, 2H), 1.24 (t,
J = 7.1Hz, 3H). 13C NMR: d 177.3, 60.2, 54.0, 45.1,
39.1, 36.2 (2·), 32.5, 27.4, 25.4, 25.1 (2·), 14.5. HRMS
calcd for C13H24(35Cl)O2 (MH+): 247.1465, found:
247.1465.
1
(p = 0.001Torr). H NMR: d 4.13 (q, J = 7.1Hz, 2H),
3.51 (t, J = 6.8Hz, 2H), 2.50–2.32 (m, 2H), 1.96–1.70
(m, 8H), 1.40–1.20 (m, 2H), 1.26 (t, J = 7.2Hz, 3H).
13C NMR: d 176.6, 60.3, 47.6, 44.8, 37.3, 32.8, 30.1
(2·), 22.4, 15.8, 14.4. HRMS calcd for C11H20(37Cl)O2
(MH+): 221.1122, found: 221.1116.
6.1.5. Ethyl 1-(4-chlorobutyl)-1-cyclopentanecarboxylate
(4c). Compound 4c was prepared, likewise the procedure
described for 4d, starting from LDA (prepared from
BuLi (2.5M in hexanes, 46.0mL, 115mmol) and iPr2NH
(16.0mL, 114mmol, distilled from NaOH)), ethyl
1
1-cyclopentanecarboxylate17 (13.05g, 95% pure by H
6.1.8. t-Butyl 1-(4-iodobutyl)-1-cyclopropanecarboxylate
(5a). To a solution of 4a (10.6g, 45.7mmol) in 2-buta-
none (50mL) was added NaI (8.23g, 54.5mmol). The
reaction mixture was stirred under reflux overnight, di-
luted with Et2O (100mL), washed with a mixture of
H2O (100mL) and aqueous Na2S2O4 (0.5M, 10mL)
and brine (50mL), and dried to give 5a (14.8g, 94% pure
by GC, 94%) as a slightly yellow liquid. 1H NMR: d 3.18
(t, J = 6.9Hz, 2H), 1.76 (quintet, J = 7.1Hz, 2H), 1.62–
1.45 (m, 4H), 1.43 (s, 9H), 1.12 (dd, J = 6.7Hz, 3.8Hz,
2H), 0.60 (dd, J = 6.6Hz, 3.9Hz, 2H). 13C NMR: d
173.9, 80.0, 33.8, 33.3, 28.9, 28.2 (3·), 24.2, 15.5 (2·),
7.2. HRMS calcd for C12H21IO2 (M+): 324.0587, found:
324.0587.
NMR, 87.2mmol), and 1-bromo-4-chlorobutane
(20.0mL, 173mmol, after 1h, the resultant mixture
was allowed to warm to rt and stirred for 21h) to give,
after purification by fractional distillation under reduced
pressure, 4c (17.44g, 86%) as a slightly yellow thin oil.
Bp: T = 85–87ꢂC (p = 0.008Torr). 1H NMR: d 4.11
(q, J = 7.0Hz, 2H), 3.50 (t, J = 6.8Hz, 2H), 2.15–2.07
(m, 2H), 1.74 (quintet, J = 7.1Hz, 2H), 1.64–1.59 (m,
6H), 1.49–1.32 (m, 4H), 1.24 (t, J = 7.1Hz, 3H).
13C NMR: d 177.1, 60.2, 53.9, 44.7, 38.4, 36.1 (2·),
33.0, 25.0 (2·), 23.4, 14.4. HRMS calcd for
C12H22(35Cl)O2 (MH+): 233.1308, found: 233.1310.
6.1.6. t-Butyl 1-(5-chloropentyl)-1-cyclopropanecarboxyl-
ate (4d). Under an Ar atmosphere at 0ꢂC, BuLi (2.5M
in hexanes, 80mL, 0.20mol) was added drop wise to a
solution of iPr2NH (27.2mL, 194mmol, distilled from
NaOH) in dry THF (200mL) in 30min. The reaction
mixture was stirred for 30min, cooled to ꢀ70ꢂC and
6.1.9. Ethyl 1-(4-iodobutyl)-1-cyclobutanecarboxylate
(5b). Compound 5b was prepared, likewise the proce-
dure described for 5a, starting from 4b (21.21g,
97.0mmol) and NaI (19.07g, 127mmol) to give 5b
1
(29.91g, 99%) as a slightly yellow oil. H NMR: d 4.14
then,
t-butyl
cyclopropanecarboxylate15 (25.0g,
(q, J = 7.1Hz, 2H), 3.17 (t, J = 6.9Hz, 2H), 2.49–2.32
(m, 2H), 1.98–1.69 (m, 8H), 1.37–1.19 (m, 2H), 1.27 (t,
J = 7.1Hz, 3H). 13C NMR: d 176.5, 60.3, 47.5, 36.9,
33.7, 30.1 (2·), 26.0, 15.7, 14.5, 6.8. HRMS calcd for
C11H20IO2 (MH+): 311.0508, found: 311.0511.
176mmol) was added drop wise in 30min. The resultant
mixture was allowed to warm up to ꢀ35ꢂC, cooled
again to ꢀ70ꢂC, and then 1-bromo-5-chloropentane
(36mL, 50.7g, 273mmol) was added drop wise in
15min. The reaction mixture was allowed to reach
ꢀ5ꢂC, stirred for 3h, poured into a mixture of ice
(100mL), H2O (100mL), brine (200mL), and aqueous
HCl (2M, 200mL) and extracted with Et2O
(2 · 300mL). The combined organic layers were washed
with a mixture of brine and saturated aqueous NaHCO3
(10:1, 300mL) and dried. The remaining oil was purified
by fractional distillation under reduced pressure to give
4d (31.5g, 73%) as a colorless liquid. Bp: T = 67–74ꢂC
(p = 0.001mbar). 1H NMR: 3.52 (t, J = 6.6Hz, 2H),
1.77 (quintet, J = 6.8Hz, 2H), 1.48–1.38 (m, 6H), 1.42
(s, 9H), 1.10 (dd, J = 6.5Hz, 3.8Hz, 2H), 0.59 (dd,
J = 6.6, 3.9Hz, 2H). 13C NMR: d 174.1, 79.9, 45.2,
34.2, 32.7, 28.2 (3·), 27.20, 27.17, 24.3, 15.4 (2·).
6.1.10. Ethyl 1-(5-iodopentyl)-1-cyclopentanecarboxylate
(5c). Compound 4c (15.11g, 64.9mmol) was treated,
likewise the procedure described for 5a, with NaI
(12.53g, 83.6mmol and 2.12g, 14.1mmol after 17h).
The crude product was concentrated to ꢁ35mL, diluted
with heptane and filtered through silica. The residue was
eluted with a mixture of heptane/EtOAc = 3:1 (500mL).
The combined filtrate and washings were evaporated in
1
vacuo to give 5c (20.84g, 95% pure by H NMR, 94%)
1
as a thin yellow oil. H NMR: d 4.12 (q, J = 7.0Hz,
2H), 3.16 (t, J = 6.8Hz, 2H), 2.15–2.05 (m, 2H), 1.79
(quintet, J = 7.1Hz, 2H), 1.68–1.58 (m, 6H), 1.49–1.40
(m, 2H), 1.37–1.22 (m, 2H), 1.23 (t, J = 7.1Hz, 3H).

R. P. L. Bell et al. / Bioorg. Med. Chem. 13 (2005) 223–236
231
13C NMR: d 177.1, 60.3, 53.8, 38.0, 36.1 (2·), 33.9, 27.0,
25.0 (2·), 14.5, 6.8. HRMS calcd for C12H22IO2 (MH+):
325.0665, found: 325.0666.
(10.62g, 76.8mmol) were added while stirring vigor-
ously. After 5d, the reaction mixture was poured in an
ice/H2O mixture (500mL) and extracted with Et2O
(1 · 200mL, 2 · 100mL). The combined organic layers
were washed with brine (2 · 50mL) and dried. The
remaining residue was purified by column chromatogra-
phy (silica, heptane/EtOAc = 3:1) to give in order of elu-
tion 3d (5.67g, 90% pure by GC), an impure batch of 8b
(0.94g), and pure 8b (11.83g, 61%) as a colorless oil. 1H
NMR: d 7.86 (d, J = 8.1Hz, 2H), 7.43 (d, J = 8.1Hz,
2H), 4.45 (dd, J = 10.9, 3.5Hz, 1H), 4.11 (q,
J = 7.2Hz, 2H), 2.49 (s, 3H), 2.22–2.11 (m, 1H), 1.90–
1.77 (m, 1H), 1.67–1.57 (m, 1H), 1.53–1.42 (m, 3H),
1.24 (t, J = 7.2Hz, 3H), 1.39–1.20 (m, 4H), 1.15 (s,
6H). 13C NMR: d 177.8, 164.8, 146.5, 131.1, 130.1
(2·), 130.0 (2·), 72.8, 60.2, 42.0, 40.3, 29.0, 28.3,
25.12, 25.06 (2·), 24.5, 21.7, 14.2. HRMS calcd for
C20H29NNaO4S (MNa+): 402.1715, found: 402.1736.
6.1.11. t-Butyl 1-(5-iodopentyl)-1-cyclopropanecarboxyl-
ate (5d). Compound 5d was prepared, likewise the pro-
cedure described for 5c, starting from 4d (31.5g,
128mmol) and added NaI (24.9g, 166mmol) to give
1
5d (42.3g, 99%) as a slightly yellow liquid. H NMR:
d 3.18 (t, J = 7.1Hz, 2H), 1.82 (quintet, J = 7.1Hz,
2H), 1.48–1.33 (m, 6H), 1.42 (s, 9H), 1.10 (dd,
J = 6.8Hz,Hz, 2H), 0.58 (dd, J = 6.6, 3.9Hz, 2H). 13C
NMR: d 174.0, 79.9, 34.1, 33.6, 30.8, 28.2 (3·), 26.8,
24.3, 15.4 (2·), 7.4. HRMS calcd for C13H23IO2 (M+):
338.0743, found: 338.0743.
6.1.12. Ethyl 1-(5-iodopentyl)-1-cyclopentanecarboxylate
(5e). Compound 5e was prepared, likewise the procedure
described for 5a, starting from 4e (21.26g, 86.1mmol),
NaI (20.87g, 139mmol) and NaHCO3 (0.10g, 1.2mmol)
to give 5e (28.74g, 94% pure by GC, 93%) as a thin yel-
6.2. General procedures for alkylation of TosMIC
1
low oil. H NMR: d 4.11 (q, J = 7.1Hz, 2H), 3.16 (t,
6.2.1. Method A. t-Butyl 1-[9-[1-(tert-butoxycarbon-
yl)cyclopropyl]-5-oxononyl]-1-cyclopropanecarboxylate
(6d). Under a N2 atmosphere, NaH (60% (w/w) in min-
eral oil, 2.91g, 72.8mmol) was added portion wise to a
solution of TosMIC (5.85g, 30.0mmol) and Bu4NI
(1.10g, 2.98mmol) in dry DMSO (100mL) while stirring
vigorously and cooling with a water bath. After 10min,
3b (16.56g, 94% pure by GC, 56.2mmol) was added
drop wise in 20min and stirring was continued for 1h
and 50min. Then, H2O (100mL) was added drop wise
and the resultant mixture was extracted with Et2O
(3 · 100mL). The combined organic layers were washed
with brine (2 · 100mL) and dried. The remaining oil
was purified by column chromatography (silica, hep-
tane/EtOAc = 6:1) to give t-butyl 1-{9-[1-(t-butoxycar-
bonyl)cyclopropyl]-5-isocyano-5-[(4-methylphenyl)sul-
fonyl]nonyl}-1-cyclopropanecarboxylate (10.00g) as a
slightly yellow oil.
J = 7.1Hz, 2H), 2.14–2.06 (m, 2H), 1.80 (quintet,
J = 7.1Hz, 2H), 1.68–1.59 (m, 6H), 1.48–1.32 (m, 4H),
1.27–1.17 (m, 2H), 1.24 (t, J = 7.2Hz, 3H). 13C NMR:
d 177.3, 60.2, 54.0, 39.1, 36.1 (2·), 33.4, 31.0, 25.1
(2·), 25.0, 14.5, 7.2. HRMS calcd for C14H26IO2
(MH+): 339.0821, found: 339.0823.
6.1.13. {7-Ethoxy-6,6-dimethyl-1-[(4-methylphenyl)sulfon-
yl]-7-oxoheptyl}(methylidyne)ammonium (8a). To
a
mixture of K2CO3 (13.18g, 95.6mmol) and Bu4NI
(2.35g, 6.36mmol) in dry DMF (50mL) was added a
solution of 3a18 (24.00g, 95.6mmol) and TosMIC
(12.41g, 63.7mmol) in dry DMF (50mL) in 20min
under a N2 atmosphere while stirring vigorously. After
4d, H2O (100mL) was added drop wise while keeping
the temperature below 25ꢂC by cooling with an ice-bath.
The resultant mixture was extracted with Et2O
(3 · 200mL). The combined organic layers were washed
with saturated aqueous NaHCO3 (2 · 200mL) and
dried. The remaining residue was purified by column
chromatography (silica, heptane/EtOAc = 6:1; a layer
of NaHCO3 was put on the base of the column) to give
8a (15.68g, 42.8mmol, 67%) as a slightly yellow oil,
which slowly solidified on standing. An analytical sample
was obtained after recrystallization (0.43g) from iPr2O/
heptane at ꢁ4ꢂC to give 8a (0.30g) as a white solid.
Mp: 38–39ꢂC. 1H NMR: d 7.84 (d, J = 8.4Hz, 2H),
7.40 (d, J = 7.8Hz, 2H), 4.43 (dd, J = 3.3, 10.8Hz, 1H),
4.10 (q, J = 7.1Hz, 2H), 2.48 (s, 3H), 2.23–2.12 (m,
1H), 1.90–1.77 (m, 1H), 1.66–40 (m, 4H), 1.38–1.22 (m,
2H), 1.24 (t, J = 7.1Hz, 3H), 1.15 (s, 6H). 13C NMR: d
177.3, 164.6, 146.3, 131.0, 129.93 (2·), 129.87 (2·),
72.8, 60.4, 42.2, 40.2, 28.4, 26.0, 25.35, 25.30, 24.2,
22.0, 14.5. Anal. Calcd for C19H27NO4S: C, 62.44; H,
7.45; N, 3.83, found: C, 62.57; H, 7.57; N, 3.96.
6.2.2. Acidic hydrolysis of alkylated TosMIC intermedi-
ate. The above mentioned oil (10.00g) was dissolved in
CH2Cl2 (200mL) and concd aqueous HCl (4mL) was
added. After stirring vigorously for 1h, H2O (100mL)
was added and the layers were separated. The aqueous
phase was extracted with CH2Cl2 (100mL) and the com-
bined organic layers were washed with saturated aque-
ous NaHCO3 (3 · 100mL) and dried. The remaining
residue was purified by column chromatography (silica,
heptane/EtOAc = 10:1) to give 6d (5.80g, 49%) as a col-
orless oil. 1H NMR: d 2.39 (t, J = 7.3Hz, 4H), 1.63–1.38
(m, 30H), 1.10 (dd, J = 6.6, 3.9Hz, 4H), 0.59 (dd,
J = 6.7, 3.9Hz, 4H). 13C NMR: d 211.1, 174.4 (2·),
79.9 (2·), 42.7 (2·), 33.9 (2·), 28.0 (6·), 27.4 (2·), 24.1
(2·), 24.0 (2·), 15.2 (4·). HRMS calcd for C25H43O5
(MH+): 423.3111, found: 423.3111.
6.2.3. Method B. Ethyl 1-9-[1-(ethoxycarbonyl)cyclo-
butyl]-5-oxononyl-1-cyclobutanecarboxylate (6f). Under
a N2 atmosphere at 0ꢂC, KOtBu (8.61g, 76.7mmol)
was added portion wise to a solution of 5b (24.83g,
80.1mmol) and TosMIC (7.26g, 36.4mmol) in N,N-
dimethylacetamide (DMAc, 150mL). After 30min, the
6.1.14. {8-Ethoxy-7,7-dimethyl-1-[(4-methylphenyl)sulfon-
yl]-8-oxooctyl}(methylidyne)ammonium (8b). Under a
N2 atmosphere, TosMIC (10.01g, 51.3mmol) and 3d1
(20.41g, 77.0mmol) were dissolved in dry DMF
(100mL) and Bu4NI (1.89g, 5.12mmol) and K2CO3

232
R. P. L. Bell et al. / Bioorg. Med. Chem. 13 (2005) 223–236
reaction mixture was allowed to warm to rt, stirred for
1.5h, and diluted with DMAc (10mL). Then, 5b
(2.01g, 6.5mmol) and KOtBu (0.81g, 7.2mmol) were
added followed by another portion of 5b (1.00g,
3.2mmol) and KOtBu (0.86g, 7.7mmol) after 1h. After
1h, the reaction mixture was poured into a mixture of
Et2O (700mL) and aqueous NaCl (10%, 500mL) and
the layers were separated. The organic layer was washed
with brine (1 · 500mL, 1 · 300mL) and dried. The
remaining residue was purified by column chromatogra-
phy (silica, heptane/EtOAc = 6:1) to give ethyl 1-9-[1-
(ethoxycarbonyl)cyclobutyl]-5-isocyano-5-[(4-methyl-
phenyl)sulfonyl]nonyl-1-cyclobutanecarboxylate (18.35g)
as a slightly yellow oil. Part of this oil (15.62g,
27.9mmol) was hydrolyzed with concd aqueous HCl
(75mL) according to the procedure described for 6d to
give, after purification by column chromatography (sil-
ica, heptane/EtOAc = 6:1), 6f (9.99g, 82%) as a slightly
yellow liquid, after evaporation from CH2Cl2
tion by column chromatography (silica, heptane/
EtOAc = 40:1), 6c (9.83g, >90% pure by NMR, 43%)
as a colorless oil. H NMR: d 4.09 (q, J = 7.2Hz, 2H),
2.38 (t, J = 7.2Hz, 4H), 1.62–1.35 (m, 10H), 1.41 (s,
9H), 1.26–1.17 (m, 2H), 1.24 (t, J = 7.2Hz, 3H), 1.14
(s, 6H), 1.09 (dd, J = 6.9, 4.2Hz, 2H), 0.59 (dd,
J = 6.3, 3.6Hz, 2H). 13C NMR: d 210.5, 177.4, 174.0,
79.8, 60.2, 42.8, 42.6, 42.1, 40.5, 34.0, 28.2 (3·), 27.5,
25.2 (2·), 24.7, 24.3, 24.2, 24.1, 15.3 (2·), 14.4. HRMS
calcd for C23H41O5 (MH+): 397.2954, found: 397.2956.
1
6.2.6.
Ethyl
11-[1-(ethoxycarbonyl)cyclobutyl]-2,2-
dimethyl-7-oxoundecanoate (6e). Compound 6e was pre-
pared likewise Method C starting from 8a (11.01g,
30.1mmol), 5b (10.28g, 33.1mmol), and KOtBu
(4.06g, 36.2mmol) to give, after purification by column
chromatography (silica, heptane/EtOAc = 6:1; a layer of
NaHCO3 was put on the base of the column), ethyl 1-
[11-ethoxy-5-isocyano-10,10-dimethyl-5-[(4-methylphen-
yl)sulfonyl]-11-oxoundecyl]-1-cyclobutanecarboxylate
(14.11g) as a colorless oil. Part of this oil (13.86g,
25.3mmol) was treated with concd aqueous HCl
(50mL), as described for 6d, to give crude 6e, which
was stirred up in heptane (50mL) and the resultant pre-
cipitate was filtered off and washed with heptane
(3 · 50mL). The combined filtrates were washed with
aqueous NaOH (1M, 2 · 50mL) and brine (50mL)
1
(100mL). H NMR: d 4.12 (q, J = 7.1Hz, 4H), 2.44–
2.32 (m, 8H), 1.93–1.79 (m, 8H), 1.77–1.72 (m, 4H),
1.55 (quintet, J = 7.5Hz, 4H), 1.25 (t, J = 7.1Hz, 6H),
1.21–1.10 (m, 4H). 13C NMR: d 210.2, 176.7 (2·), 60.2
(2·), 47.6 (2·), 42.6 (2·), 37.9 (2·), 30.1 (4·), 24.7
(2·), 24.1 (2·), 15.7 (2·), 14.4 (2·). HRMS calcd for
C23H38O5 (M+): 394.2719, found: 394.2703.
1
6.2.4. Method C. Ethyl 13-[1-(t-butoxycarbonyl)cyclo-
propyl]-2,2-dimethyl-8-oxotridecanoate (6k). Under a N2
atmosphere at 0ꢂC, a solution of 8b (28.4g, 75.0mmol)
in N,N-dimethylacetamide (DMAc, 125mL) followed
by a solution of 5d (25.4g, 75.0mmol) in DMAc
(125mL) were added drop wise in 60 and 30min, respec-
tively, to a solution of KOtBu (8.83g, 79.0mmol) in
DMAc (250mL). The mixture was allowed to reach rt
and stirring was continued for 2h. Then, the reaction
mixture was quenched by the drop wise addition of
H2O (250mL) while cooling with an ice-bath. The
resultant mixture was extracted with Et2O (3 · 250mL)
and the combined organic layers were washed with brine
(2 · 250mL) and dried to give a yellow oil (43.02g). Part
of this oil (42.50g) was hydrolyzed with concd aqueous
HCl (34mL) according to the procedure described for 6d
to give, after purification by column chromatography
(silica, heptane/EtOAc = 8:1), 6k (19.0g, 95% pure by
and dried to give 6e (9.44g, >90% pure by H NMR,
75%) as a slightly yellow oil. 1H NMR: d 4.12 (q,
J = 7.1Hz, 2H), 4.09 (q, J = 7.1Hz, 2H), 2.50–2.29 (m,
2H), 2.37 (t, J = 7.4Hz, 4H), 1.95–1.70 (m, 6H), 1.61–
1.44 (m, 6H), 1.30–1.09 (m, 4H), 1.25 (t, J = 7.1Hz,
3H), 1.24 (t, J = 7.1Hz, 3H), 1.14 (s, 6H). 13C NMR:
d 210.1, 177.3, 176.6, 60.1 (2·), 47.5, 42.57 (2·), 42.1,
40.4, 37.8, 30.0 (2·), 25.2 (2·), 24.7, 24.6, 24.2, 24.1,
15.7, 14.4, 14.3. HRMS calcd for C22H39O5 (MH+):
383.2797, found: 383.2798.
6.2.7.
Ethyl
1-9-[1-(ethoxycarbonyl)cyclopentyl]-5-
oxononyl-1-cyclopentanecarboxylate (6g). Compound
6g was prepared likewise Method B starting from Tos-
MIC (4.27g, 21.4mmol), 5c (18.18g, 95% pure by H
1
NMR, 53.3mmol), and KOtBu (5.14g, 45.8mmol and
after 3h, and another 1.5h, respectively, 0.98g, 8.7mmol
and 0.48, 4.3mmol) at 0ꢂC to give, after purification by
column chromatography and coevaporation from
CH2Cl2 (silica, heptane/EtOAc = 6:1) ethyl 1-9-[1-(eth-
oxycarbonyl)cyclopentyl]-5-isocyano-5-[(4-methylphen-
1
1H NMR, 57%) as a slightly yellow oil. H NMR: d
4.09 (q, J = 7.2Hz, 2H), 2.37 (t, J = 7.2Hz, 2H), 2.36
(t, J = 7.2Hz, 2H), 1.62–1.35 (m, 10H), 1.41 (s, 9H),
1.30–1.21 (m, 6H), 1.24 (t, J = 7.2Hz, 3H), 1.14 (s,
6H), 1.09 (dd, J = 6.6, 3.9Hz, 2H), 0.58 (dd, J = 6.3,
3.6Hz, 2H). 13C NMR: d 210.8, 177.6, 174.1, 79.8,
60.2, 42.9. 42.8, 42.2, 40.6, 34.1, 29.8, 29.6, 28.2 (3·),
27.6, 25.3 (2·), 24.9, 24.3, 23.9, 23.8, 15.3 (2·), 14.4.
HRMS calcd for C25H45O5 (MH+): 425.3267, found:
425.3267.
yl)sulfonyl]nonyl-1-cyclopentanecarboxylate
(11.63g,
containing ꢁ11% (w/w) CH2Cl2, 82%) as a slightly yel-
low oil. Part of this oil (11.00g, containing ꢁ11% (w/
w) CH2Cl2, 16.7mmol) was dissolved in CH2Cl2
(150mL) and treated with concd aqueous HCl (15mL)
for 4h. Then, the reaction mixture was washed with
brine (100mL) and aqueous NaCl (10% (w/w),
100mL). On addition of saturated aqueous NaHCO3
(100mL), CH2Cl2 (50mL), and H2O (100mL) a milky
suspension was formed, which was concentrated to
approximately 75mL. The resultant mixture was ex-
tracted with Et2O (1 · 150mL, 2 · 50mL). The com-
bined extracts were washed with saturated aqueous
NaHCO3 (150mL) and brine (100mL and 50mL) and
6.2.5. Ethyl 11-[1-(t-butoxycarbonyl)cyclopropyl]-2,2-
dimethyl-7-oxoundecanoate (6c). Compound 6c was pre-
pared likewise Method C starting from 8a (20.5g,
55.9mmol), 5a (18.11g, 55.9mmol)19 and KOtBu
(6.57g, 58.7mmol) to give a yellow oil (31.79g). Part
of this oil (30.63g) was treated with concd aqueous
HCl (23mL), as described for 6d, to give, after purifica-
1
dried to give 6g (6.51g, >90% pure by H NMR, 83%)

R. P. L. Bell et al. / Bioorg. Med. Chem. 13 (2005) 223–236
233
1
as a slightly yellow oil. H NMR: d 4.10 (q, J = 7.1Hz,
3.8Hz, 4H), 0.58 (dd, J = 6.6, 3.9Hz, 4H). 13C NMR:
d 210.9, 174.1 (2·), 79.8 (2·), 42.9 (2·), 34.1 (2·), 29.6
(2·), 28.2 (6·), 27.7 (2·), 24.4 (2·), 24.0 (2·), 15.4
(4·). HRMS calcd for C27H46NaO5 (MNa+): 473.3243,
found: 473.3233.
4H), 2.35 (t, J = 7.4Hz, 4H), 2.14–2.03 (m, 4H), 1.66–
1.38 (m, 20H), 1.27–1.13 (m, 4H), 1.24 (t, J = 7.2Hz,
6H). 13C NMR: d 210.4, 177.3 (2·), 60.2 (2·), 54.0
(2·), 42.6 (2·), 39.1 (2·), 36.1 (4·), 25.8 (2·), 25.0
(4·), 24.3 (2·), 14.4 (2·). HRMS calcd for C25H42O5
(M+): 422.3032, found: 422.3035.
6.2.11. Ethyl 1-{11-[1-(ethoxycarbonyl)cyclopentyl]-6-
oxoundecyl}-1-cyclopentanecarboxylate (6m). Com-
pound 6m was prepared likewise Method B starting
from TosMIC (5.38g, 27.0mmol), 5e (24.21g, 94% pure
by GC, 67.3mmol), and KOtBu (6.40g, 57.0mmol and
after 1h, and another 1h, respectively, 1.20g, 10.7mmol
and 0.60, 5.3mmol) at 0ꢂC to give, after purification by
column chromatography (silica, heptane/EtOAc = 6:1)
and coevaporation form CH2Cl2, ethyl 1-11-[1-(ethoxy-
carbonyl)cyclopentyl]-6-isocyano-6-[(4-methylphenyl)-
6.2.8. Tetraethyl 7-oxo-2,2,12,12-tridecanetetracarboxyl-
ate (6h). Compound 6h was prepared likewise Method
A starting from TosMIC (10.63g, 53.4mmol), Bu4NI
(3.99g, 10.7mmol), NaH (60% (w/w) in mineral oil,
4.27g, 107mmol), and 3c20 (30.0g, 97.0mmol) to give,
after filtration through silica (elute: heptane/EtOAc =
2:1), 7-ethoxy-6-(ethoxycarbonyl)-1-[6-ethoxy-5-(ethoxy-
carbonyl)-5-methyl-6-oxohexyl]-6-methyl-1-[(4-methyl-
phenyl)sulfonyl]-7-oxoheptyl(methylidyne)ammonium
(27.9g) as a yellow oil. Part of this oil (26.9g) was trea-
ted with concd aqueous HCl (50mL), as described for
6d, to give, after purification by column chromatogra-
phy (silica, heptane/EtOAc = 4:1), 6h (16.21g, 71%) as
sulfonyl]undecyl-1-cyclopentanecarboxylate
(11.18g,
containing ꢁ4% (w/w) CH2Cl2, 65%) as a slightly yel-
lowish oil. Part of this oil (10.78g, 16.7mmol) was dis-
solved in CH2Cl2 (150mL) and treated with concd
aqueous HCl (15mL) for 1.5h. Then, the reaction mix-
ture was diluted with CH2Cl2 (100mL), washed with
H2O (150mL), and aqueous NaCl (10% (w/w),
2 · 150mL), and dried. The remaining residue was sus-
pended in heptane (100mL) and filtered. The filtrate
was washed with saturated aqueous NaHCO3 (100mL)
and brine (100mL), dried, and coevaporation form
CH2Cl2 to give 6m (7.26g, 90% pure by 1H NMR,
1
a yellow oil. H NMR: d 4.17 (q, J = 7.1Hz, 8H), 2.40
(t, J = 7.4Hz, 4H), 1.87–1.82 (m, 4H), 1.58 (quintet,
J = 7.4Hz, 4H), 1.38 (s, 6H), 1.28–1.18 (m, 4H), 1.25
(t, J = 7.2Hz, 12H). 13C NMR: d 210.0, 172.0 (4·),
60.8 (4·), 53.3 (2·), 42.1 (2·), 35.0 (2·), 23.6 (4·), 19.5
(2·), 13.8 (4·). HRMS calcd for C25H43O9 (MH+):
487.2907, found: 487.2944.
1
87%) as a thin slightly yellow oil. H NMR: d 4.10 (q,
6.2.9. Ethyl 2,2-dimethyl-8-oxo-10-phenyldecanoate (6j).
Compound 6j was prepared likewise Method A starting
from 8b (19.0g, 50.1mmol), Bu4NI (1.85g, 5.01mmol),
NaH (60% (w/w) in mineral oil, 2.40g, 60.0mmol),
and (2-bromoethyl)benzene (8.24mL, 60.1mmol) to give
an oil, which was treated with concd aqueous HCl
(50mL), as described for 6d, to give, after purification
by column chromatography (silica, heptane/EtOAc =
6:1), 6j (10.84g, 68%) as a yellow oil. 1H NMR: d
7.30–7.23 (m, 2H), 7.21–7.14 (m, 3H), 4.10 (q,
J = 7.2Hz, 2H), 2.89 (t, J = 7.5Hz, 2H), 2.71 (t,
J = 7.8Hz, 2H), 2.36 (t, J = 7.4Hz, 2H), 1.60–1.44 (m,
4H), 1.28–1.16 (m, 4H), 1.23 (t, J = 7.1Hz, 3H), 1.14
(s, 6H). 13C NMR: d 210.0, 177.8, 141.1, 128.4 (2·),
128.2 (2·), 126.0, 60.0, 44.1, 42.8, 42.0, 40.4, 29.7,
29.5, 25.0 (2·), 24.6, 23.5, 14.2. HRMS calcd for
C20H30O3 (M+): 318.2195, found: 318.2201.
J = 7.0Hz, 4H), 2.35 (t, J = 7.4Hz, 4H), 2.13–2.03 (m,
4H), 1.66–1.38 (m, 20H), 1.29–1.13 (m, 8H), 1.24 (t,
J = 7.1Hz, 6H). 13C NMR: d 210.7, 177.4 (2·), 60.1
(2·), 54.0 (2·), 42.7 (2·), 39.1 (2·), 36.1 (4·), 29.8
(2·), 25.9 (2·), 25.0 (4·), 23.8 (2·), 14.4 (2·). HRMS
calcd for C27H46O5 (M+): 450.3345, found 450.3347.
6.2.12. Diethyl 10-oxo-2,2,18,18-tetramethyl-nonade-
canedioate (6n). Compound 6n was prepared likewise
Method A starting from TosMIC (2.43g, 12.5mmol),
Bu4NI (0.462g, 1.25mmol), NaH (60% (w/w) in mineral
oil, 1.21g, 30.3mmol) and 3e (7.65g, 88% pure by GC,
23.0mmol) to give, after purification by column chro-
matography (silica, heptane/EtOAc = 6:1), {10-ethoxy-
1-(9-ethoxy-8,8-dimethyl-9-oxononyl)-9,9-dimethyl-1-[(4-
methylphenyl)sulfonyl]-10-oxodecyl}(methylidyne)am-
monium (5.41g) as a yellow oil. Part of this oil (5.03g)
was treated with concd aqueous HCl (30mL), as de-
scribed for 6d, to give, after purification by column
chromatography (silica, heptane/EtOAc = 7:1), 6n
6.2.10. t-Butyl 1-11-[1-(t-butoxycarbonyl)cyclopropyl]-6-
oxoundecyl-1-cyclopropanecarboxylate (6l). Compound
6l was prepared likewise Method B starting from Tos-
MIC (13.84g, 70.9mmol), 5d (24.0g and 24.0g after
1.5h in 15min, 71.0 and 71.0mmol), and KOtBu
(8.35g and 8.35g after 1.5h, 74.6mmol and 74.6mmol)
to give, after dissolving the crude product in EtOAc
(100mL) and filtration through silica (elute: heptane/
EtOAc = 1:1, 5 · 80mL) an oil (42.38g). This oil
(42.38g) was treated with concd aqueous HCl
(11.4mL), as described for 6d, to give, after purification
1
(3.21g, 57%) as a colorless oil. H NMR: d 4.11 (q,
J = 7.2Hz, 4H), 2.37 (t, J = 7.4Hz, 4H), 1.57–1.46 (m,
8H), 1.28–1.23 (m, 16H), 1.24 (t, J = 7.1Hz, 6H), 1.15
(s, 12H). 13C NMR: d 211.5, 178.0 (2·), 60.08 (2·),
60.07 (2·), 42.7 (2·), 42.1 (2·), 40.7 (2·), 29.9
(2·), 29.21 (2·), 29.15 (2·), 25.1 (2·), 24.8 (2·), 23.8
(2·), 14.2 (2·). HRMS calcd for C27H50O5 (M+):
454.3658, found: 454.3663.
by
column
chromatography
(silica,
heptane/
6.2.13. Dimethyl 6,6-dimethoxyundecanedioate (15). To a
solution of 7b13 (9.21g, 40.0mmol) in MeOH (50mL)
was added trimethyl orthoformate (100mL, 0.91mol)
and TsOH (0.60g, 3.14mmol). The solution was heated
to reflux and stirred for 2d. Et2O (250mL) and
EtOAc = 12:1), 6l (16.3g, >90% pure by 1H NMR,
1
46%) as a colorless oil. H NMR: d 2.37 (t, J = 7.4Hz,
4H), 1.62–1.49 (quintet, J = 7.4Hz, 4H), 1.48–1.36 (m,
8H), 1.41 (s, 18H), 1.33–1.20 (m, 4H) 1.09 (dd, J = 6.5,

234
R. P. L. Bell et al. / Bioorg. Med. Chem. 13 (2005) 223–236
saturated aqueous NaHCO3 (250mL) were added and
the layers were separated. The organic layer was washed
with saturated aqueous NaHCO3 (250mL) and brine
(250mL) and dried to give 15 (11.48g, 90% pure by
GC, 85%) as a dark brown oil, which was used without
further purification in the next reaction. H NMR: d
3.67 (s, 6H), 3.13 (s, 6H), 2.33 (t, J = 7.5Hz, 4H),
1.69–1.53 (m, 8H), 1.32–1.21 (m, 4H).
tion from iPr2O/heptane. Mp: 132–134ꢂC. 1H NMR
(CD3OD): d 2.45 (t, J = 6.9Hz, 4H), 1.58–1.39 (m,
12H), 1.14 (dd, J = 6.6, 3.7Hz, 4H), 0.70 (dd, J = 6.8,
3.9Hz, 4H). 13C NMR (CD3OD): d 214.4, 179.4 (2·),
43.5 (2·), 34.9 (2·), 28.5 (2·), 25.1 (2·), 24.2 (2·), 16.2
(4·). Anal. Calcd for C17H26O5: C, 65.78; H, 8.44.
Found: C, 65.40; H, 8.37.
1
6.3.3. Method F. 11-(1-Carboxy-cyclopropyl)-2,2-
dimethyl-7-oxoundecanoic acid (7c). A solution of 6c
6.2.14. 2,12-Dihydroxy-2,12-dimethyl-7-tridecanone (7i).
At 0ꢂC under a N2 atmosphere, MeMgCl (22% (w/w) in
THF, 41.5mL, 0.126mol) was added drop wise to a
solution of 15 (8.5g, 90% pure, 25.2mmol) in Et2O
(100mL) in 30min. After stirring for 30min, the reaction
mixture was allowed to warm to rt, stirred for 2.5h, and
then cooled again to 0ꢂC. The reaction was quenched by
careful addition of HCl (1M, 125mL) and the layers
were separated. The aqueous phase was extracted with
Et2O (50mL) and the combined organic layers were
washed with brine (2 · 25mL) and dried. The remaining
residue was purified by column chromatography (silica,
EtOAc) to give 6.91g of a brown oil, which was taken
up in EtOAc (25mL). Norrit (0.5g) was added and the
suspension was filtered through kieselguhr and washed
with EtOAc (50mL). The combined filtrate and wash-
ings were evaporated in vacuo to give 7i (6.73g, 90%
1
(9.27g, >90% pure by H NMR, 21.0mmol) in HCO2H
(50mL) was stirred for 1.5h, evaporated in vacuo, and
coevaporated from toluene (10mL). The remaining resi-
due was dissolved in EtOH/H2O (2:1, 100mL) and
NaOH (5.33g, 132mmol) was added. The resultant clear
solution was warmed to 80ꢂC and after 5h, EtOH was
evaporated in vacuo. The remaining solution was di-
luted with H2O to ꢁ100mL, extracted with Et2O
(3 · 100mL), acidified to pHꢁ1 with concd aqueous
HCl (ꢁ9mL) and extracted with Et2O (3 · 100mL).
The latter organic layers were combined and dried.
The remaining residue was purified by column chroma-
tography (silica, heptane/EtOAc = 2:1 (containing 1%
(v/v) HOAc)) to give 7c (5.83g, >90% pure by 1H
NMR, 80%) as a slightly yellow oil, which turns solid
when stored at ꢀ18ꢂC for several days. Mp: 49–52ꢂC.
1H NMR (CD3OD): d 2.44 (t, J = 7.2Hz, 4H), 1.57–
1.42 (m, 10H), 1.30–1.19 (m, 2H), 1.17–1.07 (m, 2H),
1.14 (s, 6H), 0.59 (dd, J = 6.6, 3.9Hz, 2H). 13C NMR
(CD3OD): d 213.5, 181.4, 178.9, 43.5, 43.4, 43.0, 41.7,
34.9, 28.5, 25.9 (3·), 25.5, 25.2, 24.3, 16.4 (2·). Anal.
Calcd for C17H28O5: C, 65.36; H, 9.03. Found: C,
65.06; H, 9.02.
1
pure by GC, 93%)14 as a dark yellow oil. H NMR: d
2.40 (t, J = 7.3Hz, 4H), 1.51–1.61 (m, 4H), 1.40–1.48
(m, 4H), 1.27–1.38 (m, 4H), 1.18 (s, 12H). 13C NMR:
d 211.6, 71.0 (2·), 43.8 (2·), 42.9 (2·), 29.4 (4·), 24.4
(2·), 24.1 (2·). HRMS calcd for C15H31O3 (MH+):
259.2273, found: 259.2278.
6.3. General procedures for ester hydrolysis
6.3.4. 11-(1-Carboxy-cyclobutyl)-2,2-dimethyl-7-oxoun-
decanoic acid (7e). Compound 7e was prepared likewise
6.3.1. Method D. 1-[9-(1-Carboxy-cyclobutyl)-5-oxonon-
yl]-1-cyclobutanecarboxylic acid (7f). LiOHÆH2O (3.94g,
93.9mmol) and H2O (30mL) were added to a solution of
6f (9.20g, 23.3mmol) in EtOH (90mL) and the resultant
mixture was stirred at reflux temperature for 17h,
allowed to cool to rt, and concentrated in vacuo to a
smaller volume. H2O (150mL) was added and the
resultant mixture was extracted with Et2O (50mL), acid-
ified with aqueous HCl (6M, 25mL), and extracted with
Et2O (1 · 100mL, 2 · 50mL). The latter organic layers
were combined, washed with brine (50mL), and dried.
The remaining residue was recrystallized from iPr2O/
heptane to give 7f (4.41g, 56%) as small, white granules.
Mp: 69–70ꢂC. 1H NMR: d 11.2 (br s, 2H), 2.50–2.37 (m,
4H), 2.39 (t, J = 7.2Hz, 4H), 1.96–1.84 (m, 8H), 1.81–
1.75 (m, 4H), 1.57 (quintet, J = 7.4Hz, 4H), 1.26–1.12
(m, 4H). 13C NMR: d 210.6, 183.4 (2·), 47.6 (2·), 42.7
(2·), 37.8 (2·), 30.1 (4·), 24.7 (2·), 24.1 (2·), 15.7
(2·). Anal. Calcd for C19H30O5: C, 67.43; H, 8.93.
Found: C, 67.19; H, 8.97.
1
Method D starting from 6e (8.83g, >90% pure by H
NMR, 20.8mmol) and LiOHÆH2O (2.91 and 1.94g after
18h, 69.4 and 46.2mmol) to give, after recrystallized
from iPr2O/heptane, 7e (5.19g, 76%) as a white solid.
1
Mp: 53–55ꢂC. H NMR: d 10.80 (br s, 2H), 2.50–2.35
(m, 2H), 2.39 (t, J = 7.2Hz, 4H), 1.98–1.74 (m, 6H),
1.65–1.49 (m, 6H), 1.31–1.11 (m, 4H), 1.18 (s, 6H). 13C
NMR: d 210.6, 184.3, 183.4, 47.6, 42.7, 42.6, 42.2,
40.5, 37.8, 30.1 (2·), 25.1 (2·), 24.8, 24.7, 24.2, 24.1,
15.7. Anal. Calcd for C18H30O5: C, 66.23; H, 9.26.
Found: C, 66.26; H, 9.37.
6.3.5. 1-[9-(1-Carboxy-cyclopentyl)-5-oxononyl]-1-cyclo-
pentanecarboxylic acid (7g). Compound 7g was prepared
likewise Method D starting from 6g (6.05g, >90% pure
by 1H NMR, 12.9mmol) and LiOHÆH2O (2.01g,
47.9mmol) to give, after crystallization from iPr2O/hep-
1
tane, 7g (5.01g, 93% pure by H NMR, 99%) as white
granules. An analytical sample was obtained after
recrystallization from iPr2O/heptane. Mp = 104–106ꢂC.
1H NMR: d 2.39 (t, J = 6.9Hz, 4H), 2.18–2.10 (m,
4H), 1.69–141 (m, 20H), 1.27–1.14 (m, 4H). 13C NMR:
d 211.1, 184.6 (2·), 53.9 (2·), 42.5 (2·), 39.0 (2·), 35.9
(4·), 25.7 (2·), 24.9 (4·), 24.0 (2·). Anal. Calcd for
C21H34O5: C, 68.82; H, 9.35. Found: C, 68.78; H, 9.47.
6.3.2. Method E. 1-[9-(1-Carboxy-cyclopropyl)-5-oxonon-
yl]-1-cyclopropanecarboxylic acid (7d). A solution of 6d
(5.31g, 12.6mmol) in HCO2H (50mL) was stirred for
3h, evaporated in vacuo, and coevaporated from tolu-
ene (3 · 25mL) to give 7d (3.89g, 99%) as a white solid.
An analytical sample was obtained after recrystalliza-

R. P. L. Bell et al. / Bioorg. Med. Chem. 13 (2005) 223–236
235
6.3.6. 2,12-Di(ethoxycarbonyl)-2,12-dimethyl-7-oxotride-
canedioic acid (7h). A solution of KOH (2.44g, >85%,
>37.0mmol) in EtOH (80mL) was added to 6h (9.00g,
18.5mmol). After stirring for 54h, another portion of
KOH (1.21g, >85%, >18.5mmol) was added and stir-
ring was continued for 16h. The reaction mixture was
evaporated in vacuo and Et2O (250mL) and H2O
(250mL) were added. The aqueous layer was separated,
acidified with aqueous HCl (2M, 50mL), and extracted
with Et2O (250mL) and CH2Cl2 (250mL). The com-
bined organic layers were dried and the remaining resi-
due was purified by column chromatography (silica,
heptane/EtOAc/HOAc = 3:2:0.01) and vacuum dried at
50ꢂC to give 7h (6.43g, 81%) as a yellow oil. 1H
NMR: d 10.40 (br s, 2H), 4.21 (q, J = 7.1Hz, 4H),
2.42 (t, J = 7.4Hz, 4H), 1.90–1.84 (m, 4H), 1.59 (quintet,
J = 7.4Hz, 4H), 1.43 (s, 6H), 1.32–1.19 (m, 4H), 1.27 (t,
J = 7.2Hz, 6H). 13C NMR: d 210.9, 177.7 (2·), 172.1
(2·), 61.5 (2·), 53.5 (2·), 42.2 (2·), 35.3 (2·), 23.8
(2·), 23.7 (2·), 19.8 (2·), 13.9 (2·). HRMS calcd for
C21H35O9 (MH+): 431.2281, found: 431.2298.
Mp = 78–85ꢂC. 1H NMR: d 2.37 (t, J = 7.4Hz, 4H),
2.18–2.10 (m, 4H), 1.65–1.45 (m, 20H), 1.29–1.25 (m,
8H). 13C NMR: d 211.5, 184.8 (2·), 54.0 (2·), 42.4
(2·), 38.9 (2·), 35.9 (4·), 29.2 (2·), 25.5 (2·), 24.9
(4·), 23.5 (2·). Anal. Calcd for C23H38O5: C, 70.02; H,
9.71, Found: C, 70.37; H, 9.72.
6.3.10.
10-Oxo-2,2,18,18-tetramethyl-nonadecanedioic
acid (7n). Compound 7n was prepared likewise Method
D starting from 6n (11.63g, 25.6mmol) and KOH
(4.31g, 77.0mmol) to give, after recrystallization from
iPr2O/heptane, 7n (7.56g, 74%) as white crystals. Mp:
74–77ꢂC. 1H NMR (CD3OD): d 2.43 (t, J = 7.3Hz,
4H), 1.57–1.50 (m, 8H), 1.33–1.21 (m, 16H), 1.14 (s,
12H). 13C NMR: d 214.5, 182.1 (2·), 43.6 (2·), 43.2
(2·), 42.0 (2·), 31.2 (2·), 30.4 (2·), 30.38 (2·), 26.2
(2·), 25.9 (4·), 25.0 (2·). Anal. Calcd for C23H42O5:
C, 69.31; H, 10.62, Found: C, 69.41; H, 10.73.
Acknowledgements
6.3.7. 13-(1-Carboxy-cyclopropyl)-2,2-dimethyl-8-oxotri-
decanoic acid (7k). Compound 7k was prepared likewise
Method F starting from 6k (18.34g, 95% pure by
1H NMR, 41.0mmol) to give 1-(11-ethoxy-10,10-
dimethyl-5,11-dioxoundecyl)-1-cyclopropanecarboxylic-
acid, which was treated with NaOH (9.68g, 241mmol)
to give, after recrystallized from iPr2O/heptane, 7k
(9.47g, 68%) as a white solid. The mother liquor was
evaporated in vacuo and the remaining residue was puri-
fied by column chromatography (heptane/EtOAc = 2:1
(containing 1% (v/v) HOAc)) and recrystallization from
iPr2O/heptane to give a second batch 7k (2.23g, 16%) as
a white solid. Mp: 65–66ꢂC. 1H NMR (CD3OD): d 2.43
(t, J = 7.2Hz, 4H), 1.58–1.42 (m, 10H), 1.35–1.20 (m,
6H), 1.14 (s, 6H), 1.15–1.06 (m, 2H), 0.70 (dd, J = 6.6,
3.9Hz, 2H). 13C NMR (CD3OD): d 213.8, 181.6,
179.0, 43.6, 43.5, 43.1, 41.9, 35.1, 31.0, 30.6, 28.7, 26.2,
25.9 (2·), 25.02, 24.96, 24.4, 16.4 (2·). Anal. Calcd
for C19H32O5: C, 67.03; H, 9.47. Found: C, 66.86; H,
9.50.
The authors wish to thank Helene I. V. Amatdjais-
Groenen and Peter M. van Galen from the Radboud
University Nijmegen for performing the HRMS and
CHN measurements. The authors also acknowledge
Janell Lutostanski, Michelle Washburn, Martha Humes,
Terri Bancero, LeighAnn Jankowski, and Greg Fici for
collection and analysis of biological samples.
References and notes
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6.3.8.
1-[11-(1-Carboxy-cyclopropyl)-6-oxoundecyl]-1-
cyclopropanecarboxylic acid (7l). Compound 7l was pre-
pared likewise Method E starting from 6l (7.50g, >90%
pure by H NMR, 15.0mmol) to give, after recrystal-
1
lized from toluene, 7l (5.06g, 99%) as colorless crystals.
1
Mp: 122–123ꢂC. H NMR (DMSO-d6): d 11.96 (br s,
2H), 2.39 (t, J = 7.4Hz, 4H), 1.50–1.33 (m, 12H),
1.25–1.15 (m, 4H), 1.03 (dd, J = 6.5, 3.5Hz, 4H), 0.68
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236
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