Design and synthesis of a selective EP4-receptor agonist. Part 3: 16-phenyl-5-thiaPGE(1) and 9-beta-halo derivatives with improved stability.

Article abstract of DOI:10.1016/S0968-0896(02)00031-7

To identify a new selective EP4-agonist with improved chemical stability, further chemical modification of those reported previously was continued. We focused our attention on chemical modification of the alpha chain of 3,7-dithiaPGE(1) and selected 5-thi

Full text of DOI:10.1016/S0968-0896(02)00031-7

Bioorganic & Medicinal Chemistry 10 (2002) 1743–1759
Design and Synthesis of a Selective EP4-Receptor Agonist.
Part 3: 16-Phenyl-5-thiaPGE1 and 9-ꢀ-Halo Derivatives
with Improved Stability
Toru Maruyama,* Masaki Asada, Tai Shiraishi, Hideyuki Yoshida,
Takayuki Maruyama, Shuichi Ohuchida, Hisao Nakai,
Kigen Kondo and Masaaki Toda
Minase Research Institute, Ono Pharmaceutical Co., Ltd., Shimamoto, Mishima, Osaka 618-8585, Japan
Received 7 November 2001; accepted 12 January 2002
Abstract—To identify a new selective EP4-agonist with improved chemical stability, further chemical modification of those reported
previously was continued. We focused our attention on chemical modification of the a chain of 3,7-dithiaPGE1 and selected
5-thiaPGE1 as a new chemical lead. Introduction of an optimized o chain to the 5-thiaPG skeleton afforded m-methoxymethyl
derivative 33a, which showed the most potent EP4-receptor agonist activity and good subtype-selectivity both in vitro and in vivo.
9b-HaloPGF derivatives were also synthesized and biologically evaluated in an attempt to block self-degradation of the b-hydroxy-
ketone moiety. Among these series, 39a and 39b showed potent agonist activity and good subtype-selectivity. Structure–activity
relationships (SARs) are also discussed. # 2002 Elsevier Science Ltd. All rights reserved.
structure4 remains to be solved. To search for a more
chemically stable structure, we continued further chem-
Introduction
Stimulation of the EP4-receptor by PGE2 leads to an
increase in intracellular cAMP level, which has been
suggested to be coordinated with the cytoprotective
activity of PGE2 such as a protection of the organs and/
or tissues from damage.1 The above biological activities
are considered to be due to the improvement of blood
flow and the modulation of inflammatory cytokine gen-
eration.2 Identification of a highly selective EP4-recep-
tor agonist, which is chemically stable, would contribute
not only to determination of the biological role of the
EP4-receptor but also to development of clinically use-
ful drugs without side effects such as constriction of the
uterus. Identification of 3,7-dithiaPGE1 with a 16-
phenyl o chain followed by further optimization of the
o chain were reported previously.3 As a result, 16-(m-
ical modification of the a chain maintaining the optimized
o chain. More chemically stable 16-phenyl-o-tetra-
nor-5-thiaPGE1 derivatives were identified (Scheme 1),
methoxymethyl)phenyl-o-tetranor-3,7-dithiaPGE1
4
was identified as the most optimized EP4-receptor
selective agonist. To develop a highly selective EP4-
receptor agonist as a clinically useful drug, the chemical
instability due to the b-hydroxy ketone moiety and the
easily enolizable structure of the 3,7-dithia partial
*Corresponding author. Tel.: +81-75-961-1151; fax: +81-75-962-
9314; e-mail: to.maruyama@ono.co.jp
Scheme 1. Discovery of 16-phenyl-o-tetranor-5-thiaPGE1 as highly
selective EP4-receptor agonists 32a, 33a and 33c.
0968-0896/02/$ - see front matter # 2002 Elsevier Science Ltd. All rights reserved.
PII: S0968-0896(02)00031-7

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T. Maruyama et al. / Bioorg. Med. Chem. 10 (2002) 1743–1759
and their structure–activity relationships (SARs) are
discussed.
Syntheses of the PGE analogues 22a–c, 26a–c, 33a, 33c
are outlined in Schemes 3–5. As described in Scheme 3,
Michael addition of the lithiated olefins, which were
prepared from the corresponding vinyl iodides 18a–c, to
the enone 198 provided 20a–c, the TBS group of which
was removed under acidic conditions to afford 21a–c.
Chemicoenzymatic hydrolysis of 21a–c in phosphate
buffer provided 22a–c. According to the same proce-
dures as described in Scheme 3, compound 23 was con-
verted to 26a–c as shown in Scheme 4. Synthesis of 33a
and 33c was accomplished by the three-component
coupling process9,10 as described in Scheme 5. Michael
addition of the vinyl iodide 18a and 18c to the enone 27
followed by trapping of the formed enolate anion with
the aldehyde 28 afforded b-hydroxyketones 29a and 29c.
Methanesulfonylation followed by elimination of the
hydroxy group of 29a and 29c provided 30a and 30c,
hydrogenation of which was carried out by tri-n-butyl-
tin hydride reduction to afford 31a and 31c, respec-
tively. Deprotection of TBS ether was simultaneously
performed under acidic conditions to give 32a and 32c,
and then their chemicoenzymatic hydrolysis provided
33a and 33c, respectively. Synthesis of 9b-haloPGF
Chemistry
The preparation of optically active vinyl iodides 18a–c is
described in Scheme 2. Aryl bromides 6a–c were con-
verted to the corresponding Grignard reagents. Ring
opening reaction of epoxide 7 with these Grignard
reagents afforded 8a–c, respectively. Removal of the
trityl group of 8a–c under acidic conditions, followed by
selective acetylation reported by Yamamoto5 provided
10a–c. After selective protection of the secondary alco-
hol of 10a–c as a tetrahydropyranyl (THP) ether, the
acetyl group was removed by hydrolysis to give alcohols
12a–c. Oxidation of 12a–c afforded the corresponding
aldehydes 13a–c, which were converted to alkynes 15a–c
by the method reported by Corey.6 After removal of the
THP group in 15a–c, reprotection of the resulting
hydroxy group as a t-butyldimethylsilyl (TBS) ether
provided 17a–c. Alkynes 17a–c were converted to the
corresponding vinyl iodides 18a–c in good yield.7
Scheme 2. Preparation of optically active vinyl iodide 18a–c. Reagents: (a) Mg, CuI, THF then 7; (b) AcOH, THF, H2O; (c) AcCl, 2,4,6-collidine,
CH2Cl2; (d) DHP, p-TsOHH2O, CH2Cl2; (e) 2 N NaOH, MeOH; (f) (COCl)2, DMSO, Et3N, CH2Cl2; (g) CBr4, Ph3P, Et3N, CH2Cl2; (h) n-BuLi,
THF; (i) 4 N HCl–dioxane, MeOH; (j) TBSCl, imidazol, DMF; (k) Cp2ZrClH, I2, THF.
.
Scheme 3. Synthesis of 22a–c. Reagents: (a) 18a–c, t-BuLi, lithium (2-thienyl)cyanocuprate, ether, THF; (b) (HF)n Py, pyridine, CH3CN; (c) PLE,
EtOH, phosphate buffer.

T. Maruyama et al. / Bioorg. Med. Chem. 10 (2002) 1743–1759
1745
analogues is outlined in Schemes 6–8. Stereoselective
Results and Discussion
reduction of 20a–c with lithium tri-s-butylborohydride11
produced 34a–c, tosylation of which afforded 35a–c.
Substitution reaction of 35a–c with tetrabutylammonium
chloride12 (TBACl) and tetrabutylammonium fluoride12
(TBAF) provided 36a–c and 37a, respectively. Acid
deprotection of 36a–c and 37a followed by alkaline
hydrolysis afforded 39a–c and 41a. According to the
same procedures as described in the synthesis of 39a–c,
46a and 46c were prepared from 24a and 24c, respec-
tively (Scheme 7). According to the same procedures as
described in the synthesis of 41a, 51a was prepared from
47, preparation of which is briefly described in the
Experimental (Scheme 8).
Introduction of a sulfur atom or atoms into the a chain
of PGE1 was discovered to increase the EP4-receptor
selectivity and agonist activity. Chemical modification of
the o chain of 3,7-dithiaPGE1 was continued to further
improve the EP4-receptor selectivity and agonist activity.
Among the compounds tested, 4 showed a good profile as
a potent and selective EP4-receptor agonist. Binding
assay was conducted according to the reported method13
with minor modifications. The binding constants (Ki
values) were determined by competitive binding assay of
the test compounds using radiolabeled ligands such as
[3H]PGE2 (EP-receptors) and [3H]Iloprost (IP-receptor).
.
Scheme 4. Synthesis of 26a–c. Reagents: (a) 18a–c, t-BuLi, lithium (2-thienyl)cyanocuprate, ether, THF; (b) (HF)n Py, pyridine, CH3CN; (c) PLE,
EtOH, phosphate buffer.
Scheme 5. Synthesis of 33a and 33c. Reagents: (a) 18a or 18c, t-BuLi, lithium (2-thienyl)cyanocuprate, ether, THF then 28; (b) MsCl, DMAP,
.
CH2Cl2; (c) n-Bu3SnH, (tBuO)2; (d) (HF)n Py, pyridine, CH3CN; (e) PLE, EtOH, phosphate buffer.
Scheme 6. Synthesis of 9b-haloPGE2 analogues 39a–c and 41a. Reagents: (a) lithium tri-s-butylborohydride, THF; (b) p-TsCl, pyridine, DMAP; (c)
TBACl, K2CO3, toluene; (d) TBAF, K2CO3, toluene; (e) p-TsOH, MeOH; (f) 1 N NaOH, MeOH.

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T. Maruyama et al. / Bioorg. Med. Chem. 10 (2002) 1743–1759
Functional assay was conducted as follows. The intra-
cellular Ca2+ increase using CHO cells expressing EP3-
receptors was measured to estimate the EP3-receptor
agonist activity. The intracellular cAMP production in
CHO cells expressing EP4-receptors was measured to
estimate the EP4-receptor agonist activity.
modification of the a chain of 7-thiaPGE1 529 because
of its potent EP4-receptor affinity. One of the reasons
for the instability of the series of 3,7-dithiaPGEs is their
ready enolizability based on their a-alkylthiaketone
structure.4 To avoid the ‘7-thiaPGE’ structure, our chem-
ical modifications started with transfer of the sulfur
atom from position 7 to position 6, 5, 4 or 3 to afford
53, 3, 54 and 55, respectively.9 As outlined in Table 1,
the EP4-receptor selectivity was nearly restored in
To search for chemically stable and selective EP4-
receptor agonists, we started our molecular design with
Scheme 7. Synthesis of 9b-chloroPGE1 analogues 46a and 46c. Reagents: (a) lithium tri-s-butylborohydride, THF; (b) p-TsCl, pyridine, DMAP; (c)
TBACl, K2CO3, toluene; (d) p-TsOH, MeOH; (e) 1 N NaOH, MeOH.
Scheme 8. Synthesis of 9b-fluoro-5-thiaPGE1 analogue 51a. Reagents: (a) p-TsCl, pyridine, DMAP; (b) TBAF, K2CO3, toluene; (c) p-TsOH,
MeOH; (d) 1 N NaOH, MeOH.
Table 1. Biological evaluation of thia and oxaPGE1 congeners 3 and 52–55
Compound
R
Binding Ki (nM)
EC50 (nM)
mEP4
3.7
mEP1
120
mEP2
100
mEP3
4.5
mEP4
0.7
hlP
870
52
53
3
95
52
91
75
2.0
1.9
3.7
1.2
8.7
0.5
11
1400
750
1000
3.6
54
55
27
340
49
920
1000
46
200
2.1
>104
Using membrane fractions of CHO cells expressing the prostanoid receptors, the mouse (m) EP-receptor or human (h) IP-receptor, Ki values were
determined by competitive binding assay, which was performed according to the method of Kiriyama et al. with some modifications.13 With regard
to the subtype-receptor agonist activity, EC50 values were determined based on the effects of the test compounds on the increase in the intracellular
c-AMP production.

T. Maruyama et al. / Bioorg. Med. Chem. 10 (2002) 1743–1759
1747
5-thiaPGE1 3 with potent agonistic activity. However,
6-thiaPGE1 53 and 4-thiaPGE1 54 demonstrated EP3
selectivity with marked reduction of the EP4-receptor
agonist activity. In addition, 3-thiaPGE1 55 also showed
EP3-receptor selectivity with moderate EP4-receptor
agonist activity. Thus, the EP4-receptor selectivity and
the potent agonist activity of the thiaPGEs were accep-
table only in 7-thiaPGE1 and 5-thiaPGE1. Due to its
chemical stability, 5-thiaPGE1 3 was selected as one of
the chemical leads for further modification.
EP4-receptor selectivity. In the EP4-receptor selectivity,
introduction of the optimized o chain moieties into
PGE1 (26a–c) was superior to that of PGE2 (22a–c). The
agonist activities of the 16-(m-alkoxymethyl)phenyl-
PGE1 derivatives were nearly the same as those of the
corresponding PGE2 derivatives. With regard to 16-(4-
hydroxy-3-methyl)phenyl derivatives, the EC50 value of
26c was nearly 3-fold more potent than that of 22c.
SAR of the o chain moieties found in the process of
optimization of 3,7-dithiaPGEs3 was thought to be
acceptable in these cases.
Introduction of the optimized o chain moieties in the
discovery process of 3,7-dithiaPGE1 analogues 4 and 5
into the corresponding position of PGE1 and PGE2
afforded the compounds listed in Table 2. 16-(m-Meth-
oxymethyl)phenylPGE2 22a and 16-(m-ethoxymethyl)-
phenylPGE2 22b demonstrated the higher EP4-receptor
selectivity than PGE2 retaining the agonist activity,
while 16-(3-methyl-4-hydroxy)phenylPGE2 22c showed
decreased agonist activity although it exhibited potent
We focused our attention on this EP4-receptor-selective
structural information. Based on the results shown in
Tables 1 and 2, we planned compounds 33a and 33c
with hybrid structures. These compounds showed
excellent profiles as EP4-receptor-selective agonists in
both subtype selectivity and agonist activity. The easily
enolizable structure ‘a-alkylthiacyclopentanone’ of the
3,7-dithiaPGE1 skeleton was successfully replaced by
Table 2. Biological evaluation of 16-phenyl-o-tetranorPGE1 analogues
Compound
1 (PGE2)
22a
X
R
Binding Ki (nM)
mEP3
EC50 (nM)
mEP4
3.6
mEP1
6
mEP2
22
mEP4
hlP
–CH¼CH–
5.03.1
>104
–CH¼CH–
–CH¼CH–
–CH¼CH–
–CH2–CH2–
–CH2–CH2–
–CH2–CH2–
–CH2–CH2–
–CH2–S–
>104
>104
>104
22
480290 5.0
>104
>104
>104
>104
>104
>104
>104
>104
>104
28
12
22b
700
>104
41
540
10
20
22c
>104
190
2.5
24
2 (PGE1)
26a
5.03.3
>104
>104
>104
>104
>104
1400
820
>104
2900
6.0
3.0
4.9
26b
0 7660.3960
3500
18
26c
61
33a
62056 .7
7400
0
1.6
20
33c
–CH2–S–

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T. Maruyama et al. / Bioorg. Med. Chem. 10 (2002) 1743–1759
the more chemically stable 5-thiaPGE1 skeleton with
potent agonist activity and the selectivity. The chemical
instability of 5-thiaPGEs generated from the dehydra-
tion reaction of the partial structure ‘b-hydroxycyclo-
pentanone’ of the PGE skeleton was partially improved
by converting 33a to the corresponding methyl ester
32a, because of the reduced acidity.
attack by the sulfur atom at position 5 as described
previously in the preceding communication.14 9b-
Fluoro-5-thiaPGF1 51a was stably prepared and biolo-
gically evaluated. This compound demonstrated good
subtype selectivity regarding EP4-receptor affinity,
while the agonist activity was not improved compared
with that of 46a. Thus, all the 9-haloPGF2 and PGF1
derivatives 39, 41, 46 and 51 tended to show EP4-
receptor selectivity in their binding assay, and the ago-
nist activities of PGF2 derivatives 39 and 41 tended to
be more potent than those of PGF1 derivatives 46 and
51.
PGE derivatives, which contain a b-hydroxyketone
moiety, show self-degradation starting from conversion
to the corresponding PGA derivatives. On the other
hand, it is possible to avoid these degradation pathways
in PGF derivatives. The results of biological evaluation
of 9b-haloPGF derivatives 39, 41 and 46 are shown in
Table 3. Replacement of the n-amyl moiety of 9b-
The biological activities of EP4-receptor agonists were
investigated in vivo using compound 32a. Intravenous
infusion of the methyl ester 32a (10–300 ng/kg/min),
which was metabolically hydrolyzed to the active form
33a, suppressed the increased production of plasma
TNF-a level and augmented the plasma IL-10level in
LPS-induced rats.15 Subcutaneous administration of
32a (10–100 mg/kg) also exhibited excellent efficacy in
the rat hepatitis model induced by Propionibacterium
acnes/LPS or GalN/LPS in a dose-dependent manner.14
As such, the EP4-receptor was estimated to mediate
various cytoprotective activities of PGE2 by regulation
of cytokine production. More detailed biological ana-
lyses of the EP4-receptor-selective ligands are currently
in progress in our laboratory and the details of these
studies will be reported in due course.
12
chloroPGF2 with the optimized o chain moieties
afforded 39a, 39b and 39c. These compounds exhibited
potent EP4-receptor affinity and agonist activity, while
their subtype-selectivity to EP2- and EP3-receptors
remained to be improved. The corresponding PGF1
analogues 46a and 46c exhibited potent EP4-receptor
affinity and more improved subtype selectivity, while
their agonist activities were much less potent than
those of 39a and 39c, respectively. 9b-Fluoro analogue
41a showed biological properties similar to those of the
corresponding 9-chloro analogue 39a. However, the
9b-chloro-5-thiaPGF1 analogue was too unstable to
carry out precise biological evaluation. Presumably,
this might have been due to intramolecular nucleophilic
Table 3. Biological evaluation of 9b-haloPGF analogues
Compound
39a
R1
R2
Cl
Cl
Cl
F
X
CH2OMe
CH2OEt
Me
Y
H
Binding Ki (nM)
mEP3 mEP4
92 .5
EC50 (nM)
mEP4
mEP1
98012
mEP2
hIP
0
>104
3.3
39b
H
7000
3100
1700
5400
2100
>104
24
290
44
2200
94
1.5
7.7
3.4
2.7
>104
>104
>104
>104
>104
>104
1.9
39c
OH
H
44
41a
CH2OMe
CH2OMe
Me
58
14
160
730
270
46a
Cl
Cl
F
H
370
740
46c
OH
H
1400
3100
>104
1500
48
51a
CH2OMe
32

T. Maruyama et al. / Bioorg. Med. Chem. 10 (2002) 1743–1759
1749
Summary
removed by evaporation to give 8a as a yellow oil (95.8
1
g, >100%). H NMR (200 MHz, CDCl3) d 7.5–7.1 (m,
19H), 4.40(s, 2H), 4.1–3.9 (m, 1H), 3.37 (s, 3H), 3.3–3.1
(m, 2H), 2.9–2.7 (m, 2H), 2.23 (brd, 1H).
To identify EP4-receptor selective agonists applicable to
clinical studies, we continued chemical modification of
those reported previously. Among the compounds tested,
5-thiaPG analogues 33a, 33c and 9-b-haloPG analogue
39a were investigated. The methyl ester 32a of 33a was
selected as a clinical candidate because of its improved
chemical stability. Compound 32a, which metabolically
produces 33a, did not show uterine contractile activity
at the therapeutic dose. These observations indicated
that 32a showed subtype-selectivity in vivo.
2-(S)-Hydroxy-3-(3-ethoxymethyl)phenylpropan-1-ol tri-
1
tyl ether 8b. 95% yield; H NMR (200 MHz, CDCl3) d
7.48–7.01 (m, 19H), 4.44 (s, 2H), 4.05–3.93 (m, 1H),
3.51 (q, J=7.2 Hz, 2H), 3.20(dd, J=9.3, 4.5 Hz, 1H),
3.13 (dd, J=9.3, 6.3 Hz, 1H), 2.81 (dd, J=13.8, 5.5 Hz,
1H), 2.74 (dd, J=13.8, 7.5 Hz, 1H), 2.21 (d, J=4.5 Hz,
1H), 1.23 (t, J=7.2 Hz, 3H).
2-(S)-Hydroxy-3-(4-tetrahydropyranyloxy-3-methyl)phe-
nylpropan-1-ol trityl ether 8c. 100% yield; 1H NMR
(200 MHz, CDCl3): d 7.5–7.2 (m, 16H), 7.0–6.85 (m,
2H), 5.4–5.35 (m, 1H), 4.0–3.8 (m, 2H), 3.65–3.5 (m,
1H), 3.2–3.1 (m, 2H), 2.8–2.6 (m, 2H), 2.21 (s, 3H),
2.25–2.15 (m, 1H), 2.1–1.5 (m, 6H).
Experimental
General procedures
Analytical samples were homogeneous as confirmed by
TLC, and afforded spectroscopic results consistent with
the assigned structures. Proton nuclear magnetic reso-
nance spectra (1H NMR) were obtained on a Varian
Gemini-200, VXR-200s or Mercury300 spectrometer
using deuterated chloroform (CDCl3) or deuterated
methanol (CD3OD) as the solvent. Fast atom bom-
bardment mass spectra (FAB-MS) were obtained on a
JEOL JMS-DX303HF spectrometer. Atmospheric
pressure chemical ionization (APCI) was obtained on a
Hitachi M1200H spectrometer. Infrared spectra (IR)
were measured on a Perkin-Elmer FT-IR 1760X spec-
trometer. Melting points and results of elemental ana-
lyses were uncorrected. Column chromatography was
carried out on silica gel [Merck silica gel 60
(0.063ꢀ0.200 mm), Wako gel C200 or Fuji Silysia
BW235]. Thin layer chromatography was performed on
silica gel (Merck TLC or HPTLC plates, silica gel 60
F254). The following abbreviations for solvents and
reagents are used: tetrahydrofuran (THF), ethyl acetate
(EtOAc), dimethylformamide (DMF), dichloromethane
(CH2Cl2), methanol (MeOH), acetic acid (AcOH),
2-(S)-Hydroxy-3-(3-methoxymethyl)phenylpropan-1-ol
9a. A solution of 8a (95.7 g) in THF (40mL) was dilu-
ted with AcOH (200 mL) and H2O (40mL). After stir-
ring for 3 h at 65 ꢁC, 160mL of water was added at that
temperature. The reaction mixture was cooled to
room temperature and the precipitates were removed
by filtration and washed with AcOH–H2O (50–50
mL). The filtrate was concentrated and the contained
water was removed by azeotropic evaporation with
toluene to give 9a as a pale brown oil (46.9 g). 1H NMR
(200 MHz, CDCl3) d 7.35–7.10(m, 4H), 4.43 (s, 2H),
4.05–3.90 (m, 1H), 3.71 (dd, J=11, 3 Hz, 1H), 3.52 (dd,
J=11. 7 Hz, 1H), 3.41 (s, 3H), 2.8–2.7 (m, 2H), 2.2–1.5
(br, 2H).
2-(S)-Hydroxy-3-(3-ethoxymethyl)phenylpropan-1-ol 9b.
1H NMR (200 MHz, CDCl3) d 7.36–7.10(m, 4H),
4.48 (s, 2H), 4.00–3.89 (m, 1H), 3.69 (dd, J=11.4, 3.3
Hz, 1H), 3.56 (q, J=7.2 Hz, 2H), 3.51 (dd, J=11.4, 6.9
Hz, 1H), 2.80(dd, J=13.9, 6.0Hz, 1H), 2.74 (dd,
J=13.9, 7.8 Hz, 1H), 2.36–1.90(m, 2H), 1.25 (t, J=7.2
Hz, 3H).
.
p-toluenesulfonic acid monohydrate (p-TsOH H2O),
.
pyridinium poly(hydrogen fluoride) [(HF)n py, Aldrich],
porcine liver esterase (PLE).
2-(S)-Hydroxy-3-(4-hydroxy-3-methyl)phenylpropan-1-ol
1
9c. H NMR (200 MHz, CDCl3) d 6.98–6.82 (m, 2H),
6.70(d, J=7 Hz, 1H), 4.10–3.92 (m, 1H), 3.67–3.40 (m,
2H), 3.0–2.7 (br), 2.75–2.61 (m, 2H), 2.21 (s, 3H).
Preparation of optically active vinyl iodide 18a–c
2-(S)-Hydroxy-3-(3-methoxymethyl)phenylpropan-1-ol
trityl ether 8a. Magnesium turnings (5.83 g, 0.240 mol)
were dried and heated in vacuo with vigorous stirring
for 1 h under Ar. Then, anhydrous THF (100 mL) and
10drops of 1,2-dibromoethane were added. To this
mixture was added dropwise a solution of 6a (40.2 g,
0.200 mol) in THF (100 mL) in 45 min at room tem-
perature (exothermic). The resulting dark yellow solu-
tion was stirred for an additional 30min and transferred
to a suspension of copper (I) iodide (3.24 g, 17 mmol) in
THF (100 mL) at 0 ꢁC. The resulting gray suspension
was stirred for an additional 30min and then treated
with 7 (53.8 g, 0.170 mol) in THF (100 mL). The reac-
tion mixture was stirred for 20min and then poured
into saturated aqueous NH4Cl. The mixture was
extracted with EtOAc and the organic layer was washed
with brine and dried over Na2SO4. The solvent was
2-(S)-1-Acetoxy-3-(3-methoxymethyl)phenylpropane-2-ol
10a. To a pre-cooled (ꢂ78 ꢁC) solution of 9a (46.9 g)
and 2,4,6-collidine (45 mL, 0.34 mol) in CH2Cl2 (300
mL) was slowly added a solution of acetyl chloride (17
mL, 0.238 mol) in CH2Cl2 (30mL) over 20min under
Ar. After stirring for an additional 20min, the reaction
was quenched with MeOH (5 mL, 0.12 mol) and then
poured into 1 N HCl. The aqueous layer was extracted
with CH2Cl2 and the combined organic layer was
washed with water, and dried over MgSO4. The solvent
was removed by evaporation to half of the volume. The
resulting solution of 10a was used for the next reaction.
1H NMR (200 MHz, CDCl3) d 7.4–7.1 (m, 4H), 4.43 (s,
2H), 4.25–3.95 (m, 3H), 3.41 (s, 3H), 2.9–2.8 (m, 2H),
2.12 (s, 3H).

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T. Maruyama et al. / Bioorg. Med. Chem. 10 (2002) 1743–1759
2-(S)-1-Acetoxy-3-(3-ethoxymethyl)phenylpropane-2-ol
1
2-(S)-Tetrahydropyranyloxy-3-(4-tetrahydropyranyloxy-
1
10b. H NMR (200 MHz, CDCl3) d 7.44–7.02 (m, 4H),
3-methyl)phenylpropan-1-ol 12c. 51% yield from 8c; H
4.48 (s, 2H), 4.17 (dd, J=10.8, 2.7 Hz, 1H), 4.14–4.06
(m, 1H), 4.01 (dd, J=10.8, 6.6 Hz, 1H), 3.55 (q, J=6.9
Hz, 2H), 2.89–2.74 (m, 2H), 2.10(s, 3H), 1.25 (t, J=6.9
Hz, 3H).
NMR (200 MHz, CDCl3): d 7.05–6.9 (m, 3H), 5.4–5.35
(m, 1H), 4.85–4.8 and 4.3–4.2 (m, 1H), 4.05–3.4 (m,
7H), 3.0–2.5 (m, 2H), 2.23 (s, 3H), 2.1–1.4 (m, 12H).
2-(S)-Tetrahydropyranyloxy-3-(3-methoxymethyl)phenyl-
propan-1-al 13a. To a stirred solution of oxalyl chloride
(21.1 mL, 0.242 mol) in CH2Cl2 (250mL) was slowly
added a solution of dry DMSO (34.3 mL, 0.484 mol) in
CH2Cl2 (50mL) at ꢂ70 ꢁC in 10min. The resulting
solution was stirred for an additional 15 min at that
temperature and a solution of 12a (34.2 g, 0.121 mol) in
CH2Cl2 (100 mL) was added. After stirring for 30 min,
the reaction mixture was treated with Et3N (101 mL,
0.726 mol) and the resulting suspension was allowed to
warm to ꢂ30 ꢁC in 15 min. The reaction was quenched
with H2O (50mL) and then poured into ice-cold 0.5 N
HCl. The mixture was extracted with diethyl ether and
the organic layer was washed with 1 N HCl, water and
brine, and dried (MgSO4). Removal of the solvent by
2-(S)-1-Acetoxy-3-(4-hydroxy-3-methyl)phenylpropane-
2-ol 10c. Compound 10c, which was prepared from
54c, was used for the next reaction without purification.
1-Acetoxy-3-(3-methoxymethyl)phenyl-2-(S)-tetrahydro-
pyranyloxypropane 11a. To a stirred solution of 10a in
CH2Cl2 (ca. 200 mL) was successively added 3,4-dihy-
dropyran (24 mL, 0.26 mol) and p-TsOHH2O (0.32 g,
1.7 mmol) at room temperature under Ar. After stirring
for 30min, the reaction mixture was treated with Et N
3
(0.47 mL, 3.4 mmol) and then evaporated. The residue
was dissolved in EtOAc (100 mL) and hexane (200 mL)
and washed with 1 N HCl, water, saturated aqueous
NaHCO3 and brine, and dried (Na2SO4). The solvent
was removed by evaporation to give 11a as a pale yel-
1
evaporatoion gave 13a as a pale yellow oil. H NMR
1
low oil (57.6 g). H NMR (200 MHz, CDCl3) d 7.3–7.1
(200 MHz, CDCl3) d 9.75–9.00 (m, 1H), 7.30–7.10 (m,
4H), 4.80–4.75 and 4.35–4.30 (m, 1H), 4.43 (s, 2H),
4.45–4.30and 4.10–4.0(m, 1H), 3.95–3.90and 3.50–
3.40(m, 1H), 3.40(s, 3H), 3.30–2.80(m, 3H), 1.90–1.30
(m, 6H).
(m, 4H), 4.85–4.8 and 4.45–4.0(m, 1H), 4.43 (s, 2H),
4.25–3.85 and 3.5–3.2 (m, 5H), 3.39 (s, 3H), 3.05–2.8 (m,
2H), 2.10and 2.08 (s, 3H), 1.9–1.4 (m, 6H).
1-Acetoxy-3-(3-ethoxymethyl)phenyl-2-(S)-tetrahydro-
1
pyranyloxypropane 11b. H NMR (200 MHz, CDCl3) d
2-(S)-Tetrahydropyranyloxy-3-(3-ethoxymethyl)phenyl-
propan-1-al 13b. 1H NMR (200 MHz, CDCl3) d 9.71
(d, J=2.0Hz, 1/2H), 9.69 (d, J=1.4 Hz, 1/2H), 7.35–
7.01 (m, 4H), 4.80–4.74 (m, 1/2H), 4.44–4.27 (m, 1H),
4.48 (s, 2H), 4.18–3.80(m, 3/2H), 3.62–2.78 (m, 5H),
1.92–1.30(m, 6H), 1.24 (t, J=6.8 Hz, 3H).
7.32–7.08 (m, 4H), 4.86–4.40 (m, 1H), 4.47 (s, 2H),
4.28–3.24 (m, 7H), 3.04–2.78 (m, 2H), 2.08 (s, 3H),
1.94–1.30(m, 6H), 1.24 (t, J=7.0Hz, 3H).
1-Acetoxy-3-(4-tetrahydropyranyloxy-3-methyl)phenyl-2-
(S)-tetrahydropyranyloxypropane 11c. 1H NMR
(200 MHz, CDCl3) d 7.07–6.93 (m, 3H), 5.41–5.35 (m,
1H), 4.88–4.82 and 4.51–4.44 (m, 1H), 4.24–3.81 (m,
4H), 3.67–3.28 (m, 3H), 2.96–2.71 (m, 2H), 2.23 (s, 3H),
2.08 and 2.05 (s, 3H), 1.96–1.40 (m, 12H).
2-(S)-Tetrahydropyranyloxy-3-(4-tetrahydropyranyloxy-
3-methyl)phenylpropan-1-al 13c. Compound 13c, which
was prepared from 12c, was used for the next reaction
without further purification.
2-(S)-Tetrahydropyranyloxy-3-(3-methoxymethyl)phenyl-
propan-1-ol 12a. A solution of 11a (57.6 g) in 200 mL of
MeOH was treated with 2 N NaOH (100 mL) at room
temperature. After stirring for 30min, the reaction
mixture was concentrated to half of the volume and the
resulting suspension was diluted with water (200 mL).
The mixture was extracted with diethyl ether repeatedly
and the combined organic layer was washed with brine
and dried (MgSO4). Concentration and purification by
column chromatography on silica gel (EtOAc/hexane,
1/3ꢀ1/1) provided 12a as a yellow oil (43.6 g, 92%
from 8a). Rf 0.51, 0.41 (diastereomeric mixture, EtOAc/
hexane, 2/1); 1H NMR (200 MHz, CDCl3) d 7.3–7.1 (m,
4H), 4.85–4.8 and 4.25–4.2 (m, 1H), 4.42 (s, 2H), 4.05–
3.4 (m, 5H), 3.38 (s, 3H), 3.06 (dd, J=14, 6 Hz, 1H),
2.85 (dd, J=14, 8 Hz, 1H), 2.8–2.7 and 2.15–2.05 (m,
1H), 1.9–1.4 (m, 6H).
1,1-Dibromo-3-(S)-tetrahydropyranyloxy-4-(3-methoxy-
methyl)phenyl-1-butene 14a. To a stirred solution of
carbontetrabromide (120g, 0.363 mol) in CH 2Cl2 (400
mL) was added a solution of triphenylphosphine (190
g, 0.726 mol) in CH2Cl2 (320mL) at ꢂ30 ꢁC in 20min.
The resulting orange solution was cooled to ꢂ40 ꢁC
and then a cooled solution (ꢂ40 ꢁC) of 13a and Et3N
(17.3 mL, 0.124 mol) in CH2Cl2 (120mL) was added
dropwise in 10min. After stirring for 15 min, triethyla-
mine (34.6 mL, 0.248 mol) and MeOH (29.4 mL, 0.726
mol) were successively added. The resulting orange
solution was diluted with 500 mL of ether and the
precipitates were removed by filtration. The filtrate was
concentrated to half of the volume and the precipitates
were removed by filtration again. The filtrate was con-
centrated and purified by short column chromato-
graphy on silica gel (EtOAc/hexane, 1/4) to give 14a as
a pale yellow oil (49.2 g, 93% yield from 12a). 1H
NMR (200 MHz, CDCl3) d 7.35–7.12 (m, 4H), 6.54
and 6.37 (d, J=7 Hz, 1H), 4.70–4.59 (m, 1H), 4.50–
4.38 (m, 3H), 3.90–3.70and 3.55–3.40(m, 1H), 3.39 (s,
3H), 3.38–3.10and 3.30–2.83 (m, 3H), 1.82–1.30(m,
6H).
2-(S)-Tetrahydropyranyloxy-3-(3-ethoxymethyl)phenyl-
propan-1-ol 12b. 51% yield from 8b; 1H NMR
(200 MHz, CDCl3) d 7.32–7.09 (m, 4H), 4.85–4.18 (m,
1H), 4.47 (s, 2H), 4.04–3.36 (m, 7H), 3.09–2.65 (m, 2H),
1.88–1.36 (m, 7H), 1.24 (t, J=7.0Hz, 3H).

T. Maruyama et al. / Bioorg. Med. Chem. 10 (2002) 1743–1759
1751
1,1-Dibromo-3-(S)-tetrahydropyranyloxy-4-(3-ethoxyme-
thyl)phenyl-1-butene 14b. 63% yield from 12b; 1H NMR
(200 MHz, CDCl3) d 7.33–7.10(m, 4H), 6.53 and 6.34
(d, J=8.4 Hz, 1H), 4.70–4.54 (m, 1H), 4.49 (s, 2H),
4.46–4.36 (m, 1H), 3.90–3.40 (m, 3H), 3.36–3.10 (m,
1H), 3.02–2.76 (m, 2H), 1.88–1.30 (m, 6H), 1.24 (t,
J=7.0Hz, 3H).
7.05–6.95 (m, 2H), 6.73 (d, J=8 Hz, 1H), 4.73 (s, 1H),
4.53 (dq, J=6, 2 Hz, 1H), 2.92 (dd, J=6, 2 Hz, 2H),
2.49 (d, J=2 Hz, 1H), 2.24 (s, 3H), 1.90(d, J=6 Hz,
1H).
3-(S)-t-Butyldimethylsilyloxy-4-(3-methoxymethyl)phe-
nyl-1-butyne 17a. To a stirred solution of 16a (12.2 g,
64.0mmol) and imidazole (6.53 g, 96.0mmol) in DMF
(70mL) was added t-butyldimethylsilyl chloride (11.6 g,
77.1 mmol) in several portions at room temperature.
After stirring overnight, the resulting solution was
poured into ice-cooled water and the mixture was
extracted with EtOAc–hexane (1:4) twice. The com-
bined organic layer was washed with water and brine,
and dried over Na2SO4. Concentration and purification
by column chromatography (EtOAc/hexane, 1/40)
afforded 17a as a colorless oil (21.0g, 97%). 1H NMR
(200 MHz, CDCl3) d 7.3–7.1 (m, 4H), 4.5–4.45 (m, 1H),
4.44 (s, 2H), 3.37 (s, 3H), 3.0–2.95 (m, 2H), 2.41 (d, J=2
Hz, 1H), 0.83 (s, 9H), ꢂ0.02 (s, 3H), ꢂ0.08 (s, 3H).
1,1-Dibromo-3-(S)-tetrahydropyranyloxy-4-(4-tetrahydro-
pyranyloxy-3-methyl)phenyl-1-butene 14c. 79% yield
1
from 12c; H NMR (200 MHz, CDCl3): d 7.1–6.95 (m,
3H), 6.52 and 6.34 (d, J=9 Hz, 1H), 5.4–5.35 (m, 1H),
4.7–4.65 and 4.45–4.4 (m, 1H), 4.65–4.5 and 4.45–4.3
(m, 1H), 4.0–3.2 (m, 4H), 2.9–2.7 (m, 2H), 2.23 (s, 3H),
2.1–1.3 (m, 12H).
3-(S)-Tetrahydropyranyloxy-4-(3-methoxymethyl)phenyl-1-
butyne 15a To a stirred solution of 14a (49.2 g, 0.113
mol) in THF (340mL) was added dropwise n-butyl-
lithium (1.54 M in hexane, 161 mL, 0.249 mmol) in 30
min atꢂ70 ꢁC. The reaction mixture was stirred for an
additional 15 min and then poured into aqueous
NH4Cl. The mixture was extracted with EtOAc twice
and the organic layer was washed with brine and dried
(Na2SO4). The solvent was removed by evaporation to
give 15a as a pale yellow oil. 1H NMR (300 MHz,
CDCl3) d 7.33–7.14 (m, 4H), 5.03–4.98 and 4.60–4.42
(m, 2H), 4.44 (s, 2H), 4.06–3.95 and 3.55–3.48 (m, 1H),
3.37 (s, 3H), 3.39–3.11 (m, 1H), 3.10–2.97 (m, 2H), 2.45
and 2.38 (d, J=2.1 Hz, 1H), 1.89–1.25 (m, 6H).
3-(S)-t-Butyldimethylsilyloxy-4-(3-ethoxymethyl)phenyl-
1
1-butyne 17b. 89% yield; H NMR (200 MHz, CDCl3)
d 7.34–7.11 (m, 4H), 4.54–4.40(m, 3H), 3.52 (q, J=7.0
Hz, 2H), 3.07–2.86 (m, 2H), 2.40 (d, J=2.2 Hz, 1H),
1.23 (t, J=7.0Hz, 3H), 0.82 (s, 9H), ꢂ0.02 (s, 3H),
ꢂ0.07 (s, 3H).
3-(S)-t-Butyldimethylsilyloxy-4-(4-t-butyldimethylsilyloxy-
3-methyl)phenyl-1-butyne 17c. 100% yield; 1H NMR
(200 MHz, CDCl3): d 6.98 (d, J=2 Hz, 1H), 6.90(dd,
J=8, 2 Hz, 1H), 6.67 (d, J=8 Hz, 1H), 4.39 (ddd, J=8,
6, 2 Hz, 1H), 2.9–2.8 (m, 2H), 2.41 (d, J=2 Hz, 1H),
2.17 (s, 3H), 1.01 (s, 9H), 0.83 (s, 9H), 0.18 (s, 6H),
ꢂ0.04 (s, 3H), ꢂ0.09 (s, 3H).
3-(S)-Tetrahydropyranyloxy-4-(3-ethoxymethyl)phenyl-
1
1-butyne 15b. 77% yield; H NMR (200 MHz, CDCl3)
d 7.35–7.13 (m, 4H), 5.05–4.40 (m, 4H), 4.10–3.44 (m,
3H), 3.40–2.98 (m, 3H), 2.45 and 2.38 (d, J=2.0Hz,
1H), 1.95–1.30(m, 6H), 1.24 (t, J=7.0Hz, 3H).
3-(S)-t-Butyldimethylsilyloxy-1-iodo-4-(3-methoxymethyl)-
phenyl-1-butene 18a. To a stirred suspension of
3-(S)-Tetrahydropyranyloxy-4-(4-tetrahydropyranyloxy-
3-methyl)phenyl-1-butyne 15c. Compound 15c, which
was prepared from 14c, was used for the next reaction
without further purification.
Cp2ZrClH (19.9 g, 77.2 mmol) in THF (40mL) was
added 17a (20.0 g, 62.1 mmol) in THF (80 mL) at room
temperature under Ar and the reaction mixture was
stirred for 45 min. Then, the reaction mixture was
cooled to 0 ꢁC and treated with a solution of iodine
(15.5 g, 61.0mmol) in THF (80mL). After stirring for
15 min, the brown solution was diluted with hexane
(300 mL) and the resulting suspension was passed
through a short column using 10% EtOAc/hexane as an
eluent. The combined fraction was concentrated and the
residue was purified by flash column chromatography
on silica gel (EtOAc/hexane, 1/40) to give 18a as a pale
3-(S)-Hydroxy-4-(3-methoxymethyl)phenyl-1-butyne 16a.
A solution of 15a in MeOH (50mL) was treated with
p-TsOHꢃH2O (1.07 g, 5.63 mmol) at room temperature.
After stirring for 30min, the reaction mixture was dilu-
ted with EtOAc, washed with brine and dried over
Na2SO4. Concentration and purification by column
chromatography on silica gel (EtOAc/hexane, 1/4) pro-
vided 16a as a pale yellow oil (12.4 g, 58% yield from
1
1
14a). H NMR (200 MHz, CDCl3) d 7.4–7.1 (m, 4H),
red oil (21.86 g, 80%). H NMR (200 MHz, CDCl3) d
6.52 (d, J=8 Hz, 1H), 4.65–4.5 (m, 1H), 4.45 (s, 2H),
3.40(s, 3H), 2.94 (dd, J=14, 4 Hz, 1H), 2.81 (dd, J=14,
8 Hz, 1H), 1.90(brd).
7.3–7.05 (m, 4H), 6.56 (dd, J=15, 5 Hz, 1H), 6.19 (dd,
J=15, 1 Hz, 1H), 4.43 (s, 2H), 4.3–4.15 (m, 1H), 3.38 (s,
3H), 2.8–2.7 (m, 2H), 0.83 (s, 9H), ꢂ0.08 (s, 3H), ꢂ0.11
(s, 3H).
3-(S)-Hydroxy-4-(3-ethoxymethyl)phenyl-1-butyne 16b.
89% yield; 1H NMR (200 MHz, CDCl3) d 7.40–7.15
(m, 4H), 4.59 (td, J=6.4, 2.0Hz, 1H), 4.50(s, 2H), 3.55
(q, J=7.0Hz, 2H), 3.14–2.92 (m, 2H), 2.48 (d, J=2.0
Hz, 1H), 2.02–1.50 (br, 1H), 1.24 (t, J=7.0Hz, 3H).
3-(S)-t-Butyldimethylsilyloxy-1-iodo-4-(3-ethoxymethyl)-
phenyl-1-butene 18b. 58% yield; 1H NMR (200 MHz,
CDCl3) d 7.32–7.02 (m, 4H), 6.55 (dd, J=14.4, 5.7 Hz,
1H), 6.18 (dd, J=14.4 Hz, 1.0Hz, 1H), 4.48 (s, 2H),
4.30–4.16 (m, 1H), 3.52 (q, J=7.0Hz, 2H), 2.84–2.66
(m, 2H), 1.24 (t, J=7.0Hz, 3H), 0.82 (s, 9H), ꢂ0.08 (s,
3H), ꢂ0.21 (s, 3H).
3-(S)-Hydroxy-4-(4-hydroxy-3-methyl)phenyl-1-butyne 16c.
1
85% yield from 14c; H NMR (200 MHz, CDCl3): d

1752
T. Maruyama et al. / Bioorg. Med. Chem. 10 (2002) 1743–1759
3-(S)-t-Butyldimethylsilyloxy-1-iodo-4-(4-t-butyldimethyl-
silyloxy-3-methyl)phenyl-1-butene 18c. 93% yield; 1H
NMR (200 MHz, CDCl3): d 6.91 (d, J=2 Hz, 1H), 6.83
(dd, J=8, 2 Hz, 1H), 6.67 (d, J=8 Hz, 1H), 6.56 (dd,
J=14, 6 Hz, 1H), 6.17 (dd, J=14, 2 Hz, 1H), 4.2–4.1
(m, 1H), 2.65–2.6 (m, 2H), 2.17 (s, 3H), 1.01 (s, 9H),
0.83 (s, 9H), 0.18 (s, 6H),ꢂ0.10 (s, 3H),ꢂ0.22 (s, 3H).
dine (1 mL) in acetonitrile (15 mL) was cooled in an ice-
.
bath and treated with (HF)n py (Aldrich, 2 mL). The
reaction mixture was stirred for 90min without cooling.
Then, the solution was slowly poured into a biphasic
solution of EtOAc and saturated aqueous NaHCO3
with stirring. The two layers were separated and the
aqueous layer was extracted with EtOAc. The combined
EtOAc layer was washed with 1 N HCl, H2O, saturated
aqueous NaHCO3 and brine, and dried over Na2SO4.
The solvent was removed by evaporation and the resi-
due was purified by column chromatography (EtOAc/
hexane, 2/1ꢀEtOAc/MeOH, 20/1) to give 21a as pale
yellow oil (740 mg, 84%). IR (neat) 3402, 2923, 1740,
Synthesis of PGE and PGF derivatives
16-(3-Methoxymethyl)phenyl-!-tetranorPGE2 methyl ester
11,15-bis(t-butyldimethylsilyl ether) 20a. To a stirred
solution of 3-(S)-t-butyldimethylsilyloxy-1-iodo-4-(3-
methoxymethyl)phenyl-1-butene 18a (1.27 g, 2.93
mmol) in freshly distilled dry diethyl ether (12 mL) was
slowly added t-butyllithium (1.64M in pentane, 3.58
mL, 5.87 mmol) at ꢂ70 ꢁC under Ar and stirring was
continued for 1 h at that temperature. To the resulting
suspension was slowly added lithium 2-thienylcyano-
cuprate (0.25 M in THF, 12.7 mL, 3.16 mmol) and the
yellow suspension was stirred for 15 min and then a
solution of 4-(R)-t-butyldimethylsilyloxy-2-(6-carbo-
methoxy-2-hexenyl)-2-cyclopentenone 19 (800 mg, 2.26
mmol) in THF (4 mL) was added dropwise in 5 min.
The resulting yellowish mixture was stirred for a further
15 min at ꢂ70 ꢁC and then warmed to ꢂ20 ꢁC over 50
min. The reaction was quenched with saturated aqueous
NH4Cl and the mixture was vigorously stirred for 30
min without cooling. The two layers were separated and
the aqueous layer was extracted with hexane. The com-
bined organic layer was washed with aqueous NH3/
NH4Cl (1/9), water and brine, and dried over MgSO4.
The solvent was removed by evaporation and the resi-
due was purified by column chromatography on silica
gel (EtOAc/hexane, 1/20to 1/10) to afford 20a as a yel-
1
1439, 1368, 1159, 1090, 1032, 972, 704 cmꢂ1; H NMR
(200 MHz, CDCl3): d 7.3–7.1 (m, 4H), 5.71 (dd, J=15, 6
Hz, 1H), 5.50(dd, J=15, 8 Hz, 1H), 5.5–5.2 (m, 2H),
4.42 (s, 2H), 4.45–4.3 (m, 1H), 4.0–3.85 (m, 1H), 3.68 (s,
3H), 3.41 (s, 3H), 2.95–2.8 (m, 2H), 2.68 (dd, J=18, 7
Hz, 1H), 2.5–2.0(m, 11H), 1.8–1.6 (m, 2H); MS (APCI)
m/z: 413 (MꢂH2O+H)+.
16-(3-Ethoxymethyl)phenyl-!-tetranorPGE2 methyl es-
ter 21b. 73% yield in two steps; IR (neat) 3409, 2867,
1
1741, 1439, 1354, 1245, 1159, 1090, 1031, 972 cmꢂ1; H
NMR (200 MHz, CDCl3): d 7.3–7.1 (m, 4H), 5.72 (dd,
J=15, 6 Hz, 1H), 5.51 (dd, J=15, 8 Hz, 1H), 5.5–5.2
(m, 2H), 4.47 (s, 2H), 4.42 (q, J=6 Hz, 1H), 4.0–3.85
(m, 1H), 3.66 (s, 3H), 3.58 (q, J=7 Hz, 2H), 3.15–3.0
(m, 1H), 2.95–2.8 (m, 2H), 2.69 (dd, J=19, 7 Hz, 1H),
2.45–2.2 (m, 10H), 1.8–1.6 (m, 2H), 1.26 (t, J=7 Hz,
3H); MS (APCI) m/z: 427 (MꢂH2O+H)+.
16-(4-Hydroxy-3-methyl)phenyl-!-tetranorPGE2 methyl
ester 21c. 80% yield; IR (neat) 3399, 2927, 1736, 1510,
;
1438, 1266, 1158, 1079, 818, 733 cmꢂ1 1H NMR
1
low oil (1.34 g, 90%). H NMR (200 MHz, CDCl3,) d
(200 MHz, CDCl3): d 6.95 (s, 1H), 6.88 (d, J=8 Hz,
1H), 6.69 (d, J=8 Hz, 1H), 5.70(dd, J=16, 6 Hz, 1H),
5.52 (dd, J=16, 8 Hz, 1H), 5.45–5.2 (m, 2H), 5.25 (s,
1H), 4.4–4.25 (m, 1H), 4.1–3.9 (m, 1H), 3.68 (s, 3H),
2.85–2.6 (m, 4H), 2.5–2.2 (m, 6H), 2.22 (s, 3H), 2.2–2.0
(m, 3H), 1.8–1.6 (m, 3H); MS (APCI) m/z: 399
(MꢂH2O+H)+.
7.30–7.01 (m, 4H), 5.71–5.20 (m, 4H), 4.42 (s, 2H), 4.29
(m, 1H), 4.04 (m, 1H), 3.66 (s, 3H), 3.38 (s, 3H), 2.94–
1.92 (m, 12H), 1.74–1.60(m, 2H), 0.89 (s, 9H), 0.83 (s,
9H), 0.07, 0.05, ꢂ0.12 and ꢂ0.29 (s, 3H).
16-(3-Ethoxymethyl)phenyl-!-tetranorPGE2 methyl es-
ter 11,15-bis(t-butyldimethylsilyl ether) 20b. 79% yield;
1H NMR (300 MHz, CDCl3) d 7.25–7.05 (m, 4H), 5.64
(dd, J=15.2, 4.5 Hz, 1H), 5.53 (dd, J=15.2, 7.6 Hz,
1H), 5.45–5.25 (m, 2H), 4.47 (s, 2H), 4.32–4.22 (m, 1H),
4.09–3.98 (m, 1H), 3.65 (s, 3H), 3.52 (q, J=6.9 Hz, 2H),
2.82–1.94 (m, 12H), 1.74–1.60(m, 2H), 1.23 (t, J=6.9
Hz, 3H), 0.88 (s, 9H), 0.82 (s, 9H), 0.06, 0.05, ꢂ0.11 and
ꢂ0.29 (each s, 3H).
16-(3-Methoxymethyl)phenyl-!-tetranorPGE2 22a.
A
heterogeneous mixture of 21a (460mg, 1.1 mmol) and
porcine liver esterase (PLE) (Sigma, 20000U, 0.1 mL) in
EtOH (1 mL) and phosphate buffer (pH 7.4, 5 mL) was
vigorously stirred for 3 h at room temperature. The
resulting clear solution was poured into saturated aqu-
eous (NH4)2SO4 and the mixture was extracted with
EtOAc twice. The combined organic layer was dried
(Na2SO4) and concentrated, and the residue was pur-
ified by column chromatography on silica gel (CHCl3/
MeOH=50/1–20/1) to afford 22a as a pale yellow oil
(400 mg, 87%). IR (neat) 3392, 2931, 1739, 1447, 1243,
1194, 1159, 1087, 1032, 972, 915, 793, 733, 705cmꢂ1; 1H
NMR (200 MHz, CDCl3) d 7.3–7.1 (m, 4H), 5.71 (dd,
J=15, 6 Hz, 1H), 5.52 (dd, J=15, 8 Hz, 1H), 5.45–5.3
(m, 2H), 4.42 (s, 2H), 4.5–4.35 (m, 1H), 4.0–3.85 (m,
1H), 4.2–3.3 (br), 3.42 (s, 3H), 2.9–2.8 (m, 2H), 2.68 (dd,
J=18, 7 Hz, 1H), 2.45–2.0(m, 9H), 1.8–1.6 (m, 2H);
MS (FAB) m/z: 417 (M+H)+; HRMS (MALDI-TOF)
calcd for C24H32O6+Na+: 439.2097; found: 439.2112.
16-(4-t-butyldimethylsilyloxy-3-methyl)phenyl-!-tetra-
norPGE2 methyl ester 11,15-bis(t-butyldimethylsilyl ether)
1
20c. 79% yield; H NMR (300 MHz, CDCl3) d 6.92 (d,
J=2 Hz, 1H), 6.83 (dd, J=8, 2 Hz, 1H), 6.66 (d, J=8
Hz, 1H), 5.63 (dd, J=16, 4 Hz, 1H), 5.52 (dd, J=16, 8
Hz, 1H), 5.45–5.25 (m, 2H), 4.25–4.15 (m, 1H), 4.04 (q,
J=7 Hz, 1H), 3.66 (s, 3H), 2.7–1.95 (m, 12H), 2.17 (s,
3H), 1.7–1.6 (m, 2H), 1.01 and 0.89 (s, 9H) 0.84 (s, 9H),
0.18 (s, 6H), 0.07, 0.06, ꢂ0.11 and ꢂ0.27 (each s, 3H).
16-(3-Methoxymethyl)phenyl-!-tetranorPGE2 methyl es-
ter 21a. A solution of 20a (1.34 g, 2.0mmol) and pyri-

T. Maruyama et al. / Bioorg. Med. Chem. 10 (2002) 1743–1759
1753
16-(3-Ethoxymethyl)phenyl-!-tetranorPGE2 22b. 83%
yield; IR (neat) 3392, 2931, 1737, 1047, 1243, 1158,
(s, 3H), 3.52 (q, J=7.0Hz, 2H), 2.82–1.80(m, 8H),
1.70–1.08 (m, 13H), 0.88 (s, 9H), 0.82 (s, 9H), 0.06 (s,
3H), 0.05 (s, 3H), ꢂ0.13 (s, 3H), ꢂ0.28 (s, 3H).
1
1085, 972, 704 cmꢂ1; H NMR (200 MHz, CDCl3): d
7.3–7.1 (m, 4H), 5.72 (dd, J=15, 6 Hz, 1H), 5.52 (dd,
J=15, 8 Hz, 1H), 5.45–5.3 (m, 2H), 4.47 (s, 2H), 4.5–4.4
(m, 1H), 3.92 (q, J=8 Hz, 1H), 3.59 (q, J=7 Hz, 2H),
3.9–3.1 (br), 2.9–2.8 (m, 2H), 2.69 (dd, J=18, 7 Hz,
1H), 2.4–2.0(m, 9H), 1.8–1.6 (m, 2H), 1.25 (t, J=7 Hz,
3H); MS (APCI) m/z: 429 (MꢂH)ꢂ; HRMS (MALDI-
TOF) calcd for C25H34O6+Na+: 453.2253; found:
453.2237.
16-(4-t-butyldimethylsilyloxy-3-methyl)phenyl-!-tetra-
norPGE1 methyl ester 11,15-bis(t-butyldimethylsilyl
1
ether) 24c. 61% yield; H NMR (300 MHz, CDCl3) d
6.93 (d, J=2 Hz, 1H), 6.83 (dd, J=8, 2 Hz, 1H), 6.66
(d, J=8 Hz, 1H), 5.7–5.55 (m, 2H), 4.25–4.15 (m, 1H),
4.1–3.95 (m, 1H), 3.66 (s, 3H), 2.7–2.0 (m, 10H), 2.0–1.8
(m, 1H), 1.7–1.2 (m, 10H), 1.01, 0.89 and 0.84 (each s,
9H), 0.18 (s, 6H), 0.08, 0.06, ꢂ0.12 and ꢂ0.26 (each s,
3H).
16-(4-Hydroxy-3-methyl)phenyl-!-tetranorPGE2 22c.
97% yield; IR (neat) 3377, 3014, 2926, 1733, 1510,
1423, 1348, 1265, 1215, 1157, 1077, 1032, 972, 819, 756
16-(3-Methoxymethyl)phenyl-!-tetranorPGE1 methyl
ester 25a. A solution of 24a (1.01 g, 1.53 mmol) and
pyridine (2 mL) in acetonitrile (20mL) was cooled in an
1
cmꢂ1; H NMR (200 MHz, CDCl3): d 6.89 (s, 1H), 6.83
(d, J=8 Hz, 1H), 6.63 (d, J=8 Hz, 1H), 5.61 (dd,
J=15, 6 Hz, 1H), 5.48 (dd, J=15, 8 Hz, 1H), 5.4–5.2
(m, 2H), 4.23 (q, J=6 Hz, 1H), 4.00 (q, J=8 Hz, 1H),
2.78 (dd, J=18, 6 Hz, 1H), 2.7–2.5 (m, 2H), 2.4–2.2 (m,
4H), 2.14(s, 3H), 2.2–2.0(m, 5H), 1.8–1.6 (m, 2H); MS
(APCI) 401 (MꢂH)ꢂ; HRMS (MALDI-TOF) calcd for
C23H30O6+Na+: 425.1940; found: 425.1914.
.
ice-bath and treated with (HF)n py (Aldrich, 4 mL). The
reaction mixture was stirred for 120min without cool-
ing. Then, the solution was slowly poured into a bipha-
sic solution of EtOAc and saturated aqueous NaHCO3
with stirring. The two layers were separated and the
aqueous layer was extracted with EtOAc. The combined
EtOAc layer was washed with 1N HCl, H2O, saturated
aqueous NaHCO3 and brine, and dried over Na2SO4.
The solvent was removed by evaporation and the resi-
due was purified by column chromatography (EtOAc/
hexane, 2/1ꢀEtOAc/MeOH, 20/1) to give 25a as pale
yellow oil (535 mg, 81%). IR (neat) 3392, 2931, 1732,
1436, 1160, 1094, 1031, 971, 888, 792, 757, 704 cmꢂ1; 1H
NMR (200 MHz, CDCl3): d 7.28 (m, 1H), 7.23–7.10(m,
3H), 5.72 (dd, J=15, 6.2 Hz, 1H), 5.51 (dd, J=15, 8.9
Hz, 1H), 4.48–4.35 (m, 3H), 3.93 (m, 1H), 3.65 (s, 3H),
3.41 (s, 3H), 2.90(dd, J=14, 5.3 Hz, 1H), 2.82 (dd,
J=14, 7.1 Hz, 1H), 2.68 (dd, J=18, 7.5 Hz, 1H), 2.32
(m, 1H), 2.29 (t, J=7.4 Hz, 2H), 2.20(dd, J=18, 9.8
Hz, 1H), 1.96 (m, 1H), 1.66–1.16 (m, 10H); MS (APCI)
m/z: 415 (MꢂH2O+H)+.
16-(3-Methoxymethyl)phenyl-!-tetranorPGE1 methyl
ester 11,15-bis(t-butyldimethylsilyl ether) 24a. To a stir-
red solution of 3-(S)-t-butyldimethylsilyloxy-1-iode-4-
(3-methoxymethyl)phenyl-1-butene 18a (1.27 g, 2.93
mmol) in freshly distilled dry diethyl ether (12 mL) was
slowly added t-butyllithium (1.64 M in pentane, 3.58
mL, 5.87 mmol) at ꢂ70 ꢁC under Ar and the stirring
was continued for 1 h at that temperature. To the
resulting suspension was slowly added lithium 2-thie-
nylcyanocuprate (0.25 M in THF, 12.7 mL, 3.16 mmol)
and the yellow suspension was stirred for 15 min and
then a solution of 4-(R)-t-butyldimethylsilyloxy-2-(6-
carbomethoxyhexyl)-2-cyclopentenone 23 (800 mg, 2.26
mmol) in THF (5 mL) was added dropwise in 5 min.
The resulting yellowish mixture was stirred for a further
15 min at ꢂ70 ꢁC and then warmed to ꢂ20 ꢁC over 50
min. The reaction was quenched with saturated aqueous
NH4Cl and the mixture was vigorously stirred for 30
min without cooling. The two layers were separated and
the aqueous layer was extracted with hexane. The com-
bined organic layer was washed with aqueous NH3/
NH4Cl (1/9), water and brine, and dried over MgSO4.
The solvent was removed by evaporation and the resi-
due was purified by column chromatography on silica
gel (EtOAc/hexane, 1/20–1/10) to afford 24a as a yellow
16-(3-Ethoxymethyl)phenyl-!-tetranorPGE1 methyl es-
ter 25b. 60% yield; IR (neat) 3392, 2932, 2858, 1740,
1440, 1373, 1354, 1245, 1159, 1098, 1029, 972, 791, 756,
704 cmꢂ1; 1H NMR (200 MHz, CDCl3): d 7.28 (m, 1H),
7.23–7.10(m, 3H), 5.72 (dd, J=15, 6.2 Hz, 1H), 5.51
(dd, J=15, 8.9 Hz, 1H), 4.48–4.35 (m, 3H), 3.93 (m,
1H), 3.65 (s, 3H), 3.41 (s, 3H), 2.90(dd, J=14, 5.3 Hz,
1H), 2.82 (dd, J=14, 7.1 Hz, 1H), 2.68 (dd, J=18, 7.5
Hz, 1H), 2.32 (m, 1H), 2.29 (t, J=7.4 Hz, 2H), 2.20(dd,
J=18, 9.8 Hz, 1H), 1.96 (m, 1H), 1.66–1.16 (m, 10H);
MS (APCI) m/z: 429 (MꢂH2O+H)+.
1
oil (1.05 g, 70%). H NMR (200 MHz, CDCl3) d 7.30–
7.02 (m, 4H), 5.64 (dd, J=15, 4.2 Hz, 1H), 5.54 (dd,
J=15, 6.9 Hz, 1H), 4.42 (s, 2H), 4.27 (m, 1H), 4.03 (m,
1H), 3.65 (s, 3H), 3.38 (s, 3H), 2.8–2.65 (m, 2H), 2.59
(ddd, J=18, 7.0, 1.1 Hz, 1H), 2.44 (m, 1H), 2.28 (t,
J=7.5 Hz, 2H), 2.16 (dd, J=18, 8.0Hz, 1H), 1.90(m,
1H), 1.68–1.12 (m, 10H).0.88 (s, 9H), 0.83 (s, 9H), 0.07,
0.05, ꢂ0.13 and ꢂ0.29 (each s, 3H).
16-(4-Hydroxy-3-methyl)phenyl-!-tetranorPGE1 methyl
ester 25c. 84% yield; IR (neat) 3400, 2931, 1737, 1510,
1
1438, 1266, 1209, 1119, 818 cmꢂ1; H NMR (200 MHz,
CDCl3): d 7.0–6.8 (m, 2H), 6.71 (d, J=8 Hz, 1H), 5.70
(dd, J=16, 6 Hz, 1H), 5.52 (s, 1H), 5.49 (dd, J=16, 8
Hz, 1H), 4.4–4.3 (m, 1H), 4.1–3.9 (m, 1H), 3.78 (s, 3H),
2.8–2.6 (m, 4H), 2.4–2.1 (m, 8H), 2.0–1.85 (m, 1H), 1.7–
1.2 (m, 10H); MS (APCI) m/z: 40 1 (MꢂH2O+H)+.
16-(3-Ethoxymethyl)phenyl-!-tetranorPGE1 methyl es-
ter 11,15-bis(t-butyldimethylsilyl ether) 24b. 40% yield;
1H NMR (300 MHz, CDCl3) d 7.30–7.01 (m, 4H), 5.65
(dd, J=15, 4.4 Hz, 1H), 5.53 (dd, J=15, 7.0Hz, 1H),
4.47 (s, 2H), 4.34–4.22 (m, 1H), 4.09–3.95 (m, 1H), 3.65
16-(3-Methoxymethyl)phenyl-!-tetranorPGE1 26a.
heterogeneous mixture of 25a (320mg, 0.74 mmol) and
A
porcine liver esterase (PLE) (Sigma, 20000U, 0.2 mL) in

1754
T. Maruyama et al. / Bioorg. Med. Chem. 10 (2002) 1743–1759
EtOH (5 mL) and phosphate buffer (pH 7.4, 25 mL)
was vigorously stirred for 3 h at room temperature. The
resulting clear solution was poured into saturated aqu-
eous (NH4)2SO4 and the mixture was extracted with
EtOAc twice. The combined organic layer was dried
(Na2SO4) and concentrated and the residue was purified
by column chromatography on silica gel (CHCl3/
MeOH, 50/1–20/1) to afford 26a as a colorless oil (275
mg, 90%). IR (neat) 3391, 2928, 1732, 1715, 1455, 1385,
washed with H2O and brine, dried over MgSO4, and the
solvent was removed by evaporation. The residue was
purified by column chromatography on silica gel
(EtOAc/hexane, 1/4) to give 29a as a pale brown oil
(174 mg, 55%). 1H NMR (200 MHz, CDCl3) d 7.3–7.05
(m, 4H), 5.68 (dd, J=16, 5 Hz, 1H), 5.50(dd, J=16, 8
Hz, 1H), 4.43 (s, 2H), 4.35–4.2 (m, 1H), 4.15–4.0(m,
1H), 3.75–3.65 (m, 1H), 3.67 (s, 3H), 3.40(s, 3H), 2.9–
2.7 (m, 5H), 2.65–2.5 (m, 3H), 2.43 (t, J=7 Hz, 2H),
2.35–2.2 (m, 2H), 2.0–1.8 (m, 2H), 0.90 (s, 9H), 0.85 (s,
9H), 0.10, 0.08, ꢂ0.10 and ꢂ0.22 (each s, 3H).
1
1159, 1085, 971, 793, 705 cmꢂ1; H NMR (200 MHz,
CDCl3) d 7.31–7.09 (m, 4H), 5.73 (dd, J=15, 6.2 Hz,
1H), 5.52 (dd, J=15, 8.9 Hz, 1H), 4.49–4.34 (m, 3H),
3.93 (m, 1H), 3.50(br, 3H), 3.41 (s, 3H), 2.88 (dd,
J=14, 5.4 Hz, 1H), 2.82 (dd, J=14, 7.4 Hz, 1H), 2.68
(ddd, J=18, 7.4, 0.9 Hz, 1H), 2.32 (m, 1H), 2.31 (t,
J=7.4 Hz, 2H), 2.20(dd, J=18, 9.8 Hz, 1H), 1.96 (m,
1H), 1.68–1.18 (m, 10H); MS (FAB) m/z: 419 (M+H)+;
HRMS (MALDI-TOF) calcd for C24H34O6+Na+:
441.2253; found: 441.2238.
7-Hydroxy-16-(4-t-butyldimethylsilyloxy-3-methyl)phe-
nyl-!-tetranor-5-thiaPGE1 methyl ester 11,15-bis(t-bu-
tyldimethylsilyl ether) 29c. 79% yield; 1H NMR
(200 MHz, CDCl3) d 6.92 (d, J=2 Hz, 1H), 6.83 (dd,
J=8, 2 Hz, 1H), 6.67 (d, J=8 Hz, 1H), 5.69 (dd, J=15,
4 Hz, 1H), 5.55 (dd, J=15, 7 Hz, 1H), 4.25–4.0(m, 1H),
4.08 (q, J=6 Hz, 1H), 3.85–3.8 (m, 1H), 3.68 (s, 3H),
3.36 (d, J=3 Hz, 1H), 2.89 (dd, J=14, 8 Hz, 1H), 2.85–
2.7 (m, 2H), 2.7–2.5 (m, 5H), 2.43 (t, J=7 Hz, 2H),
2.35–2.2 (m, 2H), 2.16 (s, 3H), 1.9–1.85 (m, 2H), 1.01,
0.89 and 0.83 (each s, 9H), 0.18 (s, 6H), 0.10, 0.08,
ꢂ0.11 and ꢂ0.23 (each s, 3H).
16-(3-Ethoxymethyl)phenyl-!-tetranorPGE1 26b. 87%
yield; IR (neat) 3600–3200, 2931, 2858, 1733, 1446,
1411, 1353, 1243, 1159, 1084, 972, 791, 757, 705, 667
;
cmꢂ1 1H NMR (300 MHz, CDCl3): d 7.33–7.06 (m,
4H), 5.70(dd, J=15.3, 6.6 Hz, 1H), 5.48 (dd, J=15.3,
8.4 Hz, 1H), 5.30–4.60 (br), 4.46 (s, 2H), 4.42–4.28 (m,
1H), 4.00–3.82 (m, 1H), 3.57 (q, J=7.0Hz, 2H), 2.94–
2.58 (m, 3H), 2.42–2.08 (m, 4H), 2.04–1.86 (m, 1H),
1.72–1.14 (1m, 3H); MS (FAB) m/z: 419 (M+H)+;
HRMS (MALDI-TOF) calcd for C25H36O6+Na+:
455.2410; found: 455.2407.
7,8-D-16-(3-Methoxymethyl)phenyl-!-tetranor-5-thia-
PGE1 methyl ester 11,15-bis(t-butyldimethylsilyl ether)
30a. To a stirred solution of 29a (170mg, 0.24 mmol)
and DMAP (195 mg, 1.6 mmol) in CH2Cl2 (2 mL) was
added methanesulfonyl chloride (0.061 mL, 0.72 mmol)
at 0 ꢁC and the resulting suspension was stirred at that
temperature for 3 h. Then the reaction mixture was
poured into water and extracted with hexane repeatedly.
The combined organic layer was washed with brine,
dried over Na2SO4, and evaporated. The residue was
purified by column chromatography on silica gel
(EtOAc/hexane, 1/6) to afford 30a as a pale yellow oil
16-(4-Hydroxy-3-methyl)phenyl-!-tetranorPGE1 26c.
95% yield; IR (neat) 3370, 2931, 1732, 1514, 1265,
1
1119, 972, 755 cmꢂ1; H NMR (200 MHz, CDCl3): d
6.9–6.75 (m, 2H), 6.62 (d, J=8 Hz, 1H), 5.60(dd,
J=16, 6 Hz, 1H), 5.46 (dd, J=16, 8 Hz, 1H), 4.3–4.15
(m, 1H), 4.05–3.9 (m, 1H), 2.79 (dd, J=14, 6 Hz, 1H),
2.7–2.5 (m, 2H), 2.4–2.2 (m, 1H), 2.28 (t, J=7 Hz, 2H),
2.14 (s, 3H), 2.2–1.9 (m, 2H), 1.7–1.2 (m, 10H); MS
(APCI) 403 (MꢂH)ꢂ.
1
(127 mg, 78%). H NMR (200 MHz, CDCl3) d 7.3–7.0
(m, 4H), 6.8–6.65 (m, 1H), 5.6–5.45 (m, 2H), 4.42 (s,
2H), 4.3–4.2 (m, 1H), 4.15–4.1 (m, 1H), 3.67 (s, 3H),
3.45–3.4 (m, 1H), 3.39 (s, 3H), 3.2–3.05 (m, 2H), 2.8–2.7
(m, 2H), 2.6–2.2 (m, 6H), 2.0–1.8 (m, 2H), 0.85 (s, 9H),
0.83 (s, 9H), 0.08, 0.06, ꢂ0.12 and ꢂ0.20 (each s, 3H).
7-Hydroxy-16-(3-methoxymethyl)phenyl-!-tetranor-5-
thiaPGE1 methyl ester 11,15-bis(t-butyldimethylsilyl
ether) 29a. To a stirred solution of 3-(S)-t-butyldi-
methylsilyloxy-1-iodo-4-(3-methoxymethyl)phenyl-1-
butene 18a (200 mg, 0.46 mmol) in freshly distilled dry
diethyl ether (2 mL) was slowly added t-butyllithium
(1.64 M in pentane, 0.56 mL, 0.92 mmol) at ꢂ70 ꢁC
under Ar and stirring was continued for 1 h at that
temperature. To the resulting suspension was slowly
added lithium 2-thienylcyanocuprate (0.25 M in THF,
2.0mL, 0.51 mmol). The yellow suspension was stirred
for 15 min and then a solution of 4-(R)-t-butyldi-
methylsilyloxy-2-cyclopentenone 27 (97 mg, 0.46 mmol)
in THF (0.5 mL) was added dropwise in 3 min. The
resulting yellowish mixture was stirred for an additional
30min at ꢂ70 ꢁC, then 6-methoxycarbonyl-3-thia-hex-
anal 28 (90mg, 0.51 mmol) was added. After stirring for
30min, the reaction was quenched with saturated aqu-
eous NH4Cl. The mixture was vigorously stirred for 30
min without cooling and then extracted with diethyl
ether repeatedly. The combined organic layer was
7,8-D-16-(4-t-Butyldimethylsilyloxy-3-methyl)phenyl-!-
tetranor-5-thiaPGE1 methyl ester 11,15-bis(t-butyldime-
thylsilyl ether) 30c. 81% yield; 1H NMR (200 MHz,
CDCl3) d 6.92–6.62 (m, 3H), 5.53–5.46 (m, 1H), 4.27–
4.11 (m, 2H), 3.68 (s, 3H), 3.44–3.38 (m, 1H), 3.26–3.01
(m, 2H), 2.75–2.20(m, 8H), 2.18 (s, 3H), 1.97–1.80(m,
2H), 1.02 (s, 9H), 0.94–0.81 (m, 18H), 0.21 (s, 6H), 0.07,
0.02, ꢂ0.12 and ꢂ0.19 (each s, 3H).
16-(3-Methoxymethyl)phenyl-!-tetranor-5-thiaPGE1
methyl ester 11,15-bis(t-butyldimethylsilyl ether) 31a. A
mixture of 30a (125 mg, 0.18 mmol) and tributyltinhy-
dride (1 mL) was stirred at 100 ꢁC in the presence of a
catalytic amount of t-butylperoxide. After stirring for 2
h, a catalytic amount of azobisisobutyronitrile (AIBN,
ca. 10mg) was added. The reaction mixture was stirred
for an additional 30min, cooled and purified by column
chromatography (hexane to EtOAc/hexane, 1/10) to
give 31a as a pale yellow oil (33 mg, 27%).

T. Maruyama et al. / Bioorg. Med. Chem. 10 (2002) 1743–1759
1755
16-(4-t-butyldimethylsilyloxy-3-methyl)phenyl-o-tetra-
nor-5-thiaPGE1 methyl ester 11,15-bis(t-butyldi-
methylsilyl ether) 31c. 47%
Hz, 1H), 2.9–2.1 (m, 13H), 2.15 (s, 3H), 1.9–1.6 (m, 3H);
MS (APCI) m/z: 421 (MꢂH)ꢂ; HRMS (MALDI-TOF)
calcd for C22H30O6S+Na+: 445.1661; found: 445.1672.
16-(3-Methoxymethyl)phenyl-!-tetranor-5-thiaPGE1
methyl ester 32a. A solution of 31a (33 mg, 0.049
mmol) and pyridine (0.1 mL) in acetonitrile (1.5 mL)
16-(3-Methoxymethyl)phenyl-!-tetranorPGF2 methyl
ester 11,15-bis(t-butyldimethylsilyl ether) 34a. To a stir-
red solution of 20a (186 mg, 0.27 mmol) in anhydrous
THF (3 mL) was slowly added lithium tri-s-butylboro-
hydride (1.0 M solution in THF, 0.32 mL, 0.32 mmol)
atꢂ70 ꢁC. After stirring for 1 h, 1 N HCl was added.
The reaction mixture was allowed to warm to room
temperature and then extracted with EtOAc. The
organic layer was washed with water and brine, and
dried (Na2SO4). After removal of solvent by evaporation,
the residue was purified by column chromatography on
silica gel (EtOAc/hexane, 1/6–1/4) to give 34a as a
yellow oil (77 mg, 42%). 1H NMR (200 MHz, CDCl3) d
7.29–7.04 (m, 4H), 5.57–5.26 (m, 4H), 4.42 (s, 2H), 4.22
(m, 1H), 4.08 (m, 1H), 3.99 (m, 1H), 3.65 (s, 3H), 3.37
(s, 3H), 2.74 (d, J=6.4 Hz, 2H) 2.40–2.01 (m, 8H),
1.88–1.56 (m, 4H), 0.88 (s, 9H), 0.82 (s, 9H), 0.05 (s,
6H), ꢂ0.12 (s, 3H), ꢂ0.24 (s, 3H).
.
was cooled in an ice-bath and treated with (HF)n py
(Aldrich, 0.2 mL). The reaction mixture was stirred for
90min without cooling. Then, the solution was slowly
poured into a heterogenious mixture of EtOAc and
saturated aqueous NaHCO3 under stirring. The two
layers were separated and the aqueous layer was
extracted with EtOAc. The combined organic layer was
washed with 1 N HCl, H2O, saturated aqueous
NaHCO3 and brine, and dried over Na2SO4. The sol-
vent was removed by evaporation and the residue was
purified by column chromatography on silica gel
(EtOAc/hexane, 1/1 to EtOAc) to give 32a as a yellow
1
oil (16 mg, 73%). H NMR (200 MHz, CDCl3) d 7.35–
7.1 (m, 4H), 5.75 (dd, J=16, 6 Hz, 1H), 5.52 (dd, J=16,
8 Hz, 1H), 4.42 (s, 2H), 4.45–4.35 (m, 1H), 4.0–3.85 (m,
1H), 3.67 (s, 3H), 3.42 (s, 3H), 3.3–3.2 (m, 1H), 3.0–2.1
(m, 13H), 2.0–1.8 (m, 3H), 1.8–1.6 (m, 1H).
16-(3-Ethoxymethyl)phenyl-!-tetranorPGF2 methyl es-
ter 11,15-bis(t-butyldimethylsilyl ether) 34b. 58% yield;
1H NMR (200 MHz, CDCl3) d 7.29–7.02 (m, 4H), 5.50
(dd, J=15.4, 5.2 Hz, 1H), 5.45–5.26 (m, 3H), 4.46 (s,
2H), 4.30–3.94 (m, 3H), 3.64 (s, 3H), 3.52 (q, J=7.0Hz,
2H), 2.73 (d, J=6.6 Hz, 2H) 2.41–1.32 (m, 13H), 1.23 (t,
J=7.0 Hz, 3H), 0.87 (s, 9H), 0.81 (s, 9H), 0.04 (s, 6H),
ꢂ0.12 (s, 3H), ꢂ0.23 (s, 3H).
16-(4-Hydroxy-3-methyl)phenyl-!-tetranor-5-thiaPGE1
methyl ester 32c. 76% yield; IR (neat) 3400, 2921,
1
1736, 1510, 1439, 1266, 1120, 1078, 820, 733 cmꢂ1; H
NMR (200 MHz, CDCl3): d 6.93 (s, 1H), 6.87 (d, J=8
Hz, 1H), 6.71 (d, J=8 Hz, 1H), 5.71 (dd, J=15, 7 Hz,
1H), 5.62 (s, 1H), 5.50(dd, J=15, 8 Hz, 1H), 4.4–4.2
(m, 1H), 4.1–3.9 (m, 1H), 3.68 (s, 3H), 3.35–3.3 (br, 1H),
2.8–2.6 (m, 3H), 2.6–2.4 (m, 7H), 2.4–2.1 (m, 3H), 2.22
(s, 3H), 2.0–1.8 (m, 3H), 1.7–1.5 (m, 1H); MS (APCI)
m/z: 435 (MꢂH)ꢂ.
16-(4-t-butyldimethylsilyloxy-3-methyl)phenyl-!-tetra-
norPGF2 methyl ester 11,15-bis(t-butyldimethylsilyl
1
ether) 34c. 61% yield; H NMR (200 MHz, CDCl3) d
6.92 (d, J=2 Hz, 1H), 6.84 (dd, J=8, 2 Hz, 1H), 6.65
(d, J=8 Hz, 1H), 5.55–5.3 (m, 4H), 4.16 (q, J=7 Hz,
1H), 4.1–4.05 (m, 1H), 4.1–3.95 (m, 1H), 3.67 (s, 3H),
2.7–2.6 (m, 3H), 2.32 (t, J=7 Hz, 2H), 2.4–2.2 (m, 2H),
2.17 (s, 3H), 2.2–2.1 (m, 3H), 1.85–1.8 (m, 2H), 1.75–
1.65 (m, 2H), 1.5–1.4 (m, 1H), 1.01 and 0.89 (s, 9H),
0.83 (s, 9H), 0.18 (s, 6H), 0.07, 0.06, ꢂ0.11 and ꢂ0.20
(each s, 3H).
16-(3-Methoxymethyl)phenyl-!-tetranor-5-thiaPGE1
33a. A heterogeneous mixture of 32a (16 mg, 0.035
mmol) and porcine liver esterase (PLE) (Sigma,
20000U, 0.1 mL) in DMSO (1 mL) and phosphate buf-
fer (Ph 7.4, 1 mL) was stirred for 1 h at room tempera-
ture. The resulting clear solution was poured into
saturated aqueous (NH4)2SO4 and the mixture was
extracted with EtOAc twice. The organic layer was
dried (Na2SO4) and concentrated, and the residue was
purified by column chromatography on silica gel
(EtOAc/hexane/AcOH, 50/50/1 to EtOAc/AcOH, 100/1)
to afford 33a as a pale yellow oil (13 mg, 85%). IR
(neat) 3392, 2923, 1737, 1447, 1158, 1087, 972, 913, 792,
16-(3-Methoxymethyl)phenyl-9-O-tosyl-!-tetranorPGF2
methyl ester 11,15-bis(t-butyldimethylsilyl ether) 35a. A
solution of 34a (95 mg, 0.14 mmol) and p-toluenesulfo-
nyl chloride (0.53 g, 2.8 mmol) in anhydrous pyridine
(1.5 mL) was stirred at room temperature overnight.
Then, the mixture was poured into ice-cooled 1 N HCl
and extracted with EtOAc. The organic layer was
washed with water and brine, dried (Na2SO4) and
evaporated to give 35a as crude product, which was
used for the next reaction without further purification.
Compound 35b and 35c were prepared from 34a and
34c, respectively according to the same procedure as
described above.
1
733 cmꢂ1; H NMR (200 MHz, CDCl3) d 7.35–7.1 (m,
4H), 5.76 (dd, J=15, 6 Hz, 1H), 5.53 (dd, J=15, 8 Hz,
1H), 5.2–4.4 (br, 3H), 4.43 (s, 2H), 4.5–4.4 (m, 1H), 3.94
(q, J=8 Hz, 1H), 3.42 (s, 3H), 3.0–2.15 (m, 13H), 2.0–
1.8 (m, 2H), 1.8–1.6 (m, 1H); MS (APCI) m/z: 435
(MꢂH)ꢂ;
HRMS
(MALDI-TOF)
calcd
for
C23H32O6S+Na+: 459.1817; found: 459.1850.
16-(4-Hydroxy-3-methyl)phenyl-!-tetranor-5-thiaPGE1
33c. 92% yield; IR (neat) 3369, 2923, 1733, 1423, 1264,
9ꢀ-Chloro-9-deoxy-16-(3-methoxymethyl)phenyl-!-tet-
ranorPGF2 methyl ester 11,15-bis(t-butyldimethylsilyl
ether) 36a. A mixture of crude 35a and tetra-
butylammonium chloride (0.39 g, 1.4 mmol) in anhy-
drous toluene (6 mL) was stirred at 55 ꢁC for 1 h. The
1120, 1077, 973, 754 cmꢂ1
;
1H NMR (200 MHz,
CD3OD): d 6.89 (s, 1H), 6.82 (d, J=8 Hz, 1H), 6.63 (d,
J=8 Hz, 1H), 5.64 (dd, J=15, 7 Hz, 1H), 5.48 (dd,
J=15, 8 Hz, 1H), 4.22 (q, J=7 Hz, 1H), 3.99 (q, J=8

1756
T. Maruyama et al. / Bioorg. Med. Chem. 10 (2002) 1743–1759
reaction mixture was cooled to room temperature and
then poured into water. The mixture was extracted with
EtOAc and the organic layer was washed with water
and brine, and dried (Na2SO4). The solvent was
removed by evaporation to give 36a, which was used for
the next reaction without further purification. Com-
pounds 36b and 36c were prepared from 35a and 35c,
respectively, according to the procedure described
above.
(neat) 3368, 2930, 1708, 1447, 1408, 1242, 1194, 1159,
1089, 1031, 971, 912, 791, 734, 704 cmꢂ1 1H NMR
;
(200 MHz, CDCl3): d 7.33–7.08 (m, 4H), 5.60 (dd,
J=15, 5.8 Hz, 1H), 5.45 (m, 3H), 4.7–4.3 (br), 4.43 (s,
2H), 4.37 (m, 1H), 3.99 (m, 2H), 3.40(s, 3H), 2.84 (d,
J=6.6 Hz, 2H), 2.34 (t, J=7.0Hz, 2H), 2.28–1.84 (m,
8H), 1.8–1.6 (m, 2H); MS (APCI) m/z: 437 and 435
(MꢂH)ꢂ;
HRMS
(MALDI-TOF)
calcd
for
C24H33ClO5+Na+: 459.1914; found: 459.1869.
9ꢀ-Chloro-9-deoxy-16-(3-methoxymethyl)phenyl-!-tet-
ranorPGF2 methyl ester 38a. A solution of crude 36a
and p-TsOHꢃ H2O (10mg) in MeOH (2 mL) was stirred
at room temperature for 1 h. Then, the reaction mix-
ture was poured into water and extracted with EtOAc
twice. The combined organic layer was washed with
brine, dried over Na2SO4, and evaporated. The residue
was purified by short column chromatography to
remove polar product. The combined fractions were
concentrated and further purified by passage through a
Lobar column (Merck, sizeA, iPrOH/toluene, 1/20) to
give 38a as a colorless oil (38 mg, 58% in three steps).
IR (neat) 3400, 2930, 1737, 1438, 1364, 1247, 1195,
9ꢀ-Chloro-9-deoxy-16-(3-ethoxymethyl)phenyl-!-tetra-
norPGF2 39b. 91% yield; IR (neat) 3600–3200, 2975,
2931, 1708, 1445, 1408, 1353, 1244, 1159, 1094, 1029,
971, 911, 790, 734, 704 cmꢂ1 1H NMR (200 MHz,
;
CDCl3) d 7.33–7.06 (m, 4H), 6.00–5.20 (m, 7H), 4.46 (s,
2H), 4.40–4.26 (m, 1H), 4.07–3.90 (m, 2H), 3.56 (q,
J=7.0Hz, 2H), 2.81 (d, J=6.2 Hz, 2H), 2.40–1.80 (m,
10H), 1.78–1.58 (m, 2H), 1.24 (t, J=7.0Hz, 3H); MS
(APCI) m/z: 451 and 449 (MꢂH)ꢂ; HRMS (MALDI-
TOF) calcd for C25H35ClO5+Na+: 473.2071; found:
473.2071.
9ꢀ-Chloro-9-deoxy-16-(4-hydroxy-3-methyl)phenyl-!-
tetranorPGF2 39c. 99% yield; IR (neat) 3369, 2931,
1
1159, 1094, 1031, 970, 791, 754, 704 cmꢂ1; H NMR
1
(200 MHz, CDCl3) d 7.33–7.08 (m, 4H), 5.60 (dd,
J=15, 6.2 Hz, 1H), 5.42 (m, 3H), 4.42 (s, 2H), 4.33 (m,
1H), 3.99 (m, 2H), 3.67 (s, 3H), 3.40(s, 3H), 2.9–2.7
(m, 2H), 2.32 (t, J=7.5 Hz, 2H), 2.33–1.83 (m, 8H),
1.8–1.6 (m, 2H); MS (APCI) m/z: 435 and 433
(MꢂH2O+H)+.
1714, 1510, 1435, 1264, 1043, 972, 819 cmꢂ1; H NMR
(200 MHz, CDCl3) d 6.87 (s, 1H), 6.81 (d, J=8 Hz, 1H),
6.62 (d, J=8 Hz, 1H), 5.50(dd, J=15, 6 Hz, 1H), 5.5–
5.3 (m, 3H), 4.18 (q, J=6 Hz, 1H), 4.05–3.9 (m, 2H),
2.77 (dd, J=14, 6 Hz, 1H), 2.57 (dd, J=14, 8 Hz, 1H),
2.29 (t, J=7 Hz, 2H), 2.12 (s, 3H), 2.2–1.9 (m, 7H), 1.9–
1.7 (m, 1H), 1.75–1.55 (m, 2H); MS (APCI) m/z: 423
and 421 (MꢂH)ꢂ.
9ꢀ-Chloro-9-deoxy-16-(3-ethoxymethyl)phenyl-!-tetra-
norPGF2 methyl ester 38b. 48% yield in three steps; IR
(neat) 3600–3200, 2931, 1738, 1440, 1373, 1249, 1158,
9ꢀ-Fluoro-9-deoxy-16-(3-methoxymethyl)phenyl-!-tet-
ranorPGF2 methyl ester 11,15-bis(t-butyldimethylsilyl
ether) 37a. A mixture of crude 35a (prepared from 77
mg of 34a) and tetrabutylammonium fluoride (pre-
pared by concentration of 1.0M THF solution, 0.30
g, 1.16 mmol) in anhydrous toluene (6 mL) was stir-
red at 55 ꢁC for 1 h. The reaction mixture was cooled
to room temperature, then poured into water and
extracted with EtOAc. The organic layer was washed
with water and brine, and dried (Na2SO4). The sol-
vent was removed by evaporation to give 37a, which
was used for the next reaction without further pur-
ification.
1
1098, 1029, 971, 790, 704 cmꢂ1; H NMR (200 MHz,
CDCl3) d 7.32–7.05 (m, 4H), 5.57 (dd, J=15, 6.5 Hz,
1H), 5.51–5.26 (m, 3H), 4.45 (s, 2H), 4.36–4.22 (m, 1H),
4.06–3.90 (m, 2H), 3.66 (s, 3H), 3.55 (q, J=7.0Hz, 2H),
3.02–2.68 (m, 4H), 2.38–1.82 (m, 10H), 1.78–1.58 (m,
2H), 1.24 (t, J=7.0Hz, 3H); MS (APCI) m/z: 449 and
447 (MꢂH2O+H)+.
9ꢀ-Chloro-9-deoxy-16-(4-hydroxy-3-methyl)phenyl-!-
tetranorPGF2 methyl ester 38c. 65% in three steps; IR
(neat) 3369, 2927, 1715, 1436, 1266, 1211, 1120, 1031,
972, 819, 734 cmꢂ1; 1H NMR (200 MHz, CDCl3) d 6.94
(s, 1H), 6.88 (d, J=8 Hz, 1H), 6.69 (d, J=8 Hz, 1H),
5.60(dd, J=15, 6 Hz, 1H), 5.55–5.35 (m, 3H), 5.19 (s,
1H), 4.4–4.2 (m, 1H), 4.15–3.9 (m, 2H), 3.69 (s, 3H),
2.74 (d, J=7 Hz, 1H), 2.34 (t, J=7 Hz, 2H), 2.22 (s,
3H), 2.1–1.8 (m, 9H), 1.8–1.6 (m, 3H); MS (APCI) m/z:
437 and 435 (MꢂH)ꢂ.
9ꢀ-Fluoro-9-deoxy-16-(3-methoxymethyl)phenyl-!-tet-
ranorPGF2 methyl ester 40a. A solution of crude 37a
.
and p-TsOH H2O (10mg) in MeOH (2 mL) was stirred
at room temperature for 1 h. Then, the reaction mixture
was poured into water and extracted with EtOAc twice.
The combined organic layer was washed with brine,
dried over Na2SO4, and evaporated. The residue was
purified by short column chromatography on silica gel
to remove polar product. The combined fractions were
concentrated and further purified by passage through a
Lobar column (Merck, sizeA, iPrOH/toluene, 1/20) to
give 40a as an yellow oil (11 mg, 22% in three steps). IR
(neat) 3392, 2931, 1738, 1438, 1364, 1315, 1195, 1159,
9ꢀ-Chloro-9-deoxy-16-(3-methoxymethyl)phenyl-!-tet-
ranorPGF2 39a. To a stirred solution of 38a (28 mg,
0.059 mmol) in MeOH (2 mL) was added 2 N NaOH (1
mL) at room temperature. The reaction mixture was
stirred for 1 h, then poured into 1 N HCl and extracted
with EtOAc twice. The organic layer was washed with
water and brine, and dried (Na2SO4). The solvent was
removed by evaporation and the residue was purified by
column chromatography on silica gel (CHCl3/MeOH,
20/1) to afford 39a as a colorless oil (24 mg, 89%). IR
1096, 1031, 971, 792, 754, 704 cmꢂ1
;
1H NMR
(200 MHz, CDCl3) d 7.33–7.08 (m, 4H), 5.61 (dd, J=15,
6.2 Hz, 1H), 5.47 (dd, J=15, 7.4 Hz, 1H), 5.53–5.29 (m,

T. Maruyama et al. / Bioorg. Med. Chem. 10 (2002) 1743–1759
1757
2H), 4.72 (m, 1H), 4.42 (s, 2H), 4.33 (m, 1H), 3.98 (m,
1H), 3.67 (s, 3H), 3.40(s, 3H), 2.86 (dd, J=14, 5.6 Hz,
1H), 2.79 (dd, J=14, 7.0Hz, 1H), 2.32 (t, J=7.3 Hz,
2H), 2.39–1.58 (m, 10H); MS (APCI) m/z: 417
(MꢂH2O+H)+.
dine (3 mL) was stirred at room temperature for 21 h.
Then, the mixture was poured into ice-cooled 1 N HCl
and extracted with EtOAc. The organic layer was
washed with water and brine, dried (Na2SO4) and eva-
porated to give 43a as a crude product, which was used
for the next reaction without further purification. Com-
pound 43c was prepared from 42c according to the
procedure described above.
9ꢀ-Fluoro-9-deoxy-16-(3-methoxymethyl)phenyl-!-tet-
ranorPGF2 41a. To a stirred solution of 40a (7.0mg,
0.016 mmol) in MeOH (1 mL) was added 2 N NaOH
(0.5 mL) at room temperature. The reaction mixture
was stirred for 1 h, then poured into 1 N HCl and
extracted with EtOAc twice. The organic layer was
washed with water and brine, then dried (Na2SO4). The
solvent was removed by evaporation and the residue
was purified by column chromatography on silica gel
(CHCl3/MeOH, 20/1) to afford 41a as a colorless oil
(6.5 mg, 96%). IR (neat) 3368, 2930, 1708, 1448, 1382,
9ꢀ-Chloro-9-deoxy-16-(3-methoxymethyl)phenyl-!-tet-
ranorPGF1 methyl ester 11,15-bis(t-butyldimethylsilyl
ether) 44a.
A mixture of crude 43a and tetra-
butylammonium chloride (0.39 g, 1.4 mmol) in anhy-
drous toluene (6 mL) was stirred at 55 ꢁC for 1 h. The
reaction mixture was cooled to room temperature, then
poured into water and extracted with EtOAc. The
organic layer was washed with water and brine, and
dried (Na2SO4). The solvent was removed by evapora-
tion to give 44a, which was used to the next reaction
without further purification. Compound 44c was pre-
pared from 43c according to the procedure described
above.
1241, 1194, 1159, 1093, 1030, 971, 922, 792, 704 cmꢂ1
;
1H NMR (200 MHz, CDCl3) d 7.36–7.08 (m, 4H), 5.63
(dd, J=15, 5.8 Hz, 1H), 5.57–5.31 (m, 3H), 4.77 (m,
1H), 4.43 (s, 2H), 4.42 (m, 1H), 4.4–3.9 (br), 3.98 (m,
1H), 3.41 (s, 3H), 3.0–2.8 (m, 2H), 2.40–1.54 (m, 12H);
MS (APCI) m/z: 419 (MꢂH)ꢂ; HRMS (MALDI-TOF)
calcd for C24H33FO5+Na+: 443.2210; found:
443.2232.
9ꢀ-Chloro-9-deoxy-16-(3-methoxymethyl)phenyl-!-tet-
ranorPGF1 methyl ester 45a. A solution of crude 44a
.
and p-TsOH H2O (10mg) in MeOH (3 mL) was stirred
16-(3-Methoxymethyl)phenyl-!-tetranorPGF1
methyl
at room temperature for 1 h. Then, the reaction mixture
was poured into water and extracted with EtOAc twice.
The combined organic layer was washed with brine,
dried over Na2SO4, and evaporated. The residue was
purified by short-column chromatography to remove
polar products. The combined fractions were con-
centrated and further purified by passage through a
Lobar column (Merck, sizeA, iPrOH/toluene, 1/20) to
give 45a as a yellow oil (56 mg, 46% in three steps). IR
(neat) 3600–3200, 2928, 2857, 1738, 1440, 1363, 1261,
ester 11,15-bis(t-butyldimethylsilyl ether) 42a. To a stir-
red solution of 24a (278 mg, 0.42 mmol) in anhydrous
THF (8 mL) was slowly added l-selectride (1.0M solu-
tion in THF, 0.46 mL, 0.46 mmol) at ꢂ70 ꢁC. After
stirring for 1 h, to this solution was added 30% H2O2.
The reaction mixture was allowed to warm to room
temperature, then poured into 1 N HCl and extracted
with EtOAc. The organic layer was washed with water
and brine, and dried (Na2SO4). After removal of the
solvent by evaporation, the residue was purified by
column chromatography on silica gel (EtOAc/hexane,
1/10to 1/4) to give 42a as a colorless oil (174 mg, 62%).
1H NMR (200 MHz, CDCl3) d 7.30–7.03 (m, 4H), 5.48
(dd, J=15.4, 5.6 Hz, 1H), 5.34 (dd, J=15.4, 8.6 Hz,
1H), 4.42 (s, 2H), 4.29–3.94 (m, 3H), 3.65 (s, 3H),
3.37 (s, 3H), 2.73 (d, J=6.6 Hz, 2H) 2.29 (t, J=7.5
Hz, 2H), 2.24–2.12 (m, 1H), 1.86–1.10(m, 14H), 0.86
(s, 9H), 0.81 (s, 9H), 0.04 (s, 6H), ꢂ0.12 (s, 3H),
ꢂ0.23 (s, 3H).
1196, 1099, 1032, 971, 791, 704 cmꢂ1
;
1H NMR
(200 MHz, CDCl3) d 7.32–7.06 (m, 4H), 5.56 (dd,
J=15.0, 6.2 Hz, 1H), 5.42 (dd, J=15.0, 7.6 Hz), 4.41 (s,
2H), 4.36–4.20(m, 1H), 4.08–3.90(m, 2H), 3.65 (s, 3H),
3.63–3.42 (br, 1H), 3.39 (s, 3H), 2.92–2.68 (m, 3H), 2.30
(t, J=7.5 Hz, 2H), 2.25–1.20(m, 14H); MS (APCI) m/z;
435 (MꢂH2O+H)+.
9ꢀ-Chloro-9-deoxy-16-(4-hydroxy-3-methyl)phenyl-!-
tetranorPGF1 methyl ester 45c. 58% in three steps; IR
(neat) 3392, 2929, 2857, 1718, 1510, 1439, 1266, 1210,
;
1120, 1034, 972, 911, 818, 734 cmꢂ1 1H NMR
(300 MHz, CDCl3): d 6.95 (d, J=2 Hz, 1H), 6.86 (dd,
J=8, 2 Hz, 1H), 6.70(d, J=8 Hz, 1H), 5.59 (dd, J=15,
6 Hz, 1H), 5.47 (dd, J=15, 8 Hz, 1H), 5.38 (s, 1H),
4.35–4.25 (m, 1H), 4.1–4.0(m, 1H), 4.0–3.9 (m, 1H),
3.68 (s, 3H), 2.76 (d, J=7 Hz, 2H), 2.34 (t, J=7 Hz,
2H), 2.23 (s, 3H), 2.3–2.1 (m, 2H), 2.07 (d, J=3 Hz,
1H), 2.0–1.8 (m, 3H), 1.7–1.55 (m, 2H), 1.5–1.2 (m, 8H);
MS (APCI) m/z; 439 and 437 (MꢂH)ꢂ.
16-(4-t-butyldimethylsilyloxy-3-methyl)phenyl-!-tetra-
norPGF1 methyl ester 11,15-bis(t-butyldimethylsilyl
1
ether) 42c. 74% yield; H NMR (300 MHz, CDCl3) d
6.92 (d, J=2 Hz, 1H), 6.82 (dd, J=8, 2 Hz, 1H), 6.65
(d, J=8 Hz, 1H), 5.48 (dd, J=15, 6 Hz, 1H), 5.35 (dd,
J=15, 9 Hz, 1H), 4.2–4.1 (m, 2H), 4.0–3.95 (m, 1H),
3.65 (s, 3H), 2.8–2.7 (m, 3H), 2.63 (d, J=7 Hz, 2H),
2.29 (t, J=7 Hz, 2H), 2.25–2.15 (m, 1H), 2.17 (s, 3H),
1.85–1.8 (m, 2H), 1.7–1.5 (m, 5H), 1.5–1.2 (m, 8H), 1.01
and 0.87 and 0.83 (each s, 9H), 0.18 (s, 6H), 0.05 (s,
6H), ꢂ0.13 and ꢂ0.21 (each s, 3H).
9ꢀ-Chloro-9-deoxy-16-(3-methoxymethyl)phenyl-!-tet-
ranorPGF1 46a. To a stirred solution of 45a (50mg,
0.11 mmol) in MeOH (2 mL) was added 2 N NaOH (1
mL) at room temperature. The reaction mixture was
stirred for 1 h, then poured into 1 N HCl and extracted
with EtOAc twice. The combined organic layer was
16-(3-Methoxymethyl)phenyl-9-O-tosyl-!-tetranorPGF1
methyl ester 11,15-bis(t-butyldimethylsilyl ether) 43a. A
solution of 42a (174 mg, 0.26 mmol) and p-toluene-
sulfonyl chloride (1.0g, 5.2 mmol) in anhydrous pyri-

1758
T. Maruyama et al. / Bioorg. Med. Chem. 10 (2002) 1743–1759
washed with water and brine, then dried (Na2SO4). The
solvent was removed by evaporation and the residue
was purified by column chromatography on silica gel
(CHCl3/MeOH, 20/1) to afford 46a as a pale yellow oil
(48 mg, 98%). IR (neat) 3600–3200, 2928, 2856, 1708,
give 49a (0.90 g), which was used for the next reaction
without further purification.
9ꢀ-Fluoro-9-deoxy-16-(3-methoxymethyl)phenyl-5-thia-
!-tetranorPGF1 methyl ester 50a. A mixture of 49a
1
1446, 1383, 1194, 1087, 1033, 970, 791, 704 cmꢂ1; H
(0.90 g) and TsOH H2O (10mg) in MeOH (3 mL) was
.
NMR (200 MHz, CDCl3): d 7.34–7.09 (m, 4H), 5.62
(dd, J=15.4, 5.8 Hz, 1H), 5.47 (dd, J=15.4, 7.6 Hz,
1H), 4.44 (s, 2H), 4.43–4.32 (m, 1H), 4.12–3.90(m, 2H),
3.41 (s, 3H), 2.95–2.73 (m, 2H), 2.32 (t, J=6.9 Hz, 2H),
2.28–1.77 (m, 4H), 1.72–1.52 (m, 2H), 1.52–1.16 (m,
11H); MS (APCI) m/z: 437 (MꢂH)ꢂ; HRMS (MALDI-
TOF) calcd for C24H35ClO5+Na+: 461.2071; found:
461.2034.
stirred at room temperature for 15 min. The reaction
mixture was diluted with EtOAc and washed with water
and brine, and dried (Na2SO4). The solvent was
removed by evaporation and the residue was purified by
short column chromatography on silica gel (EtOAc/
hexane, 3/1) to remove polar by-products. The com-
bined fractions were evaporated and the residue was
further purified by passage through a Lobar column
(Merck, sizeA, EtOAc/hexane, 7/3 to EtOAc) to give
50a as a colorless oil (68 mg, 15% in three steps). IR
(neat) 3397, 2922, 1735, 1437, 1365, 1193, 1092, 1032,
9ꢀ-Chloro-9-deoxy-16-(4-hydroxy-3-methyl)phenyl-!-
tetranorPGF1 46c. 97% yield; IR (KBr) 3363, 2934,
1698, 1436, 1261, 1082, 976, 818 cmꢂ1
;
1H NMR
790, 703 cmꢂ1; H NMR (300 MHz, CDCl3) d 7.3–7.1
1
(300 MHz, CD3OD): d 6.87 (d, J=2 Hz, 1H), 6.80(dd,
J=8, 2 Hz, 1H), 6.62 (d, J=8 Hz, 1H), 5.49 (dd, J=15,
6 Hz, 1H), 5.40(dd, J=15, 8 Hz, 1H), 4.19 (q, J=6 Hz,
1H), 3.98 (q, J=7 Hz, 1H), 3.95 (q, J=7 Hz, 1H), 2.78
(dd, J=13, 6 Hz, 1H), 2.58 (dd, J=13, 7 Hz, 1H), 2.27
(t, J=8 Hz, 2H), 2.15 (s, 3H), 2.2–2.1 (m, 2H), 2.0–1.9
(m, 1H), 1.8–1.7 (m, 1H), 1.65–1.5 (m, 2H), 1.4–1.2 (m,
8H); MS (APCI) m/z: 425 and 423 (MꢂH)ꢂ; HRMS
(MALDI-TOF) calcd for C23H33ClO5+Na+: 447.1914;
found: 447.1939.
(m, 4H), 5.66 (dd, J=15, 6 Hz, 1H), 5.49 (dd, J=15, 8
Hz, 1H), 4.85–4.8 and 4.7–4.65 (m, 1H), 4.42 (s, 2H),
4.45–4.35 (m, 1H), 4.05–3.9 (m, 1H), 3.68 (s, 3H), 3.42 (s,
3H), 2.95–2.8 (m, 2H), 2.7–2.4 (m, 7H), 2.4–2.2 (m, 1H),
2.1–1.5 (m, 8H); MS (APCI) m/z: 437 (MꢂH2O+H)+.
9ꢀ-Fluoro-9-deoxy-16-(3-methoxymethyl)phenyl-5-thia-
!-tetranorPGF1 51a. To a stirred solution of 50a (65
mg, 0.14 mmol) in MeOH (2 mL) was added 2 N NaOH
(1 mL) at room temperature. The reaction mixture was
stirred for 1 h, then poured into 1 N HCl and extracted
with EtOAc. The organic layer was washed with water
and brine, then dried (Na2SO4). The solvent was
removed by evaporation and the residue was purified by
column chromatography on silica gel (CHCl3/MeOH,
50/1 to 20/1) to afford 51a as a colorless oil (55 mg, 87%).
IR (neat) 3376, 2924, 1712, 1446, 1381, 1192, 1091, 1033,
971, 915, 791, 704 cmꢂ1; 1H NMR (200 MHz, CDCl3): d
7.3–7.1 (m, 4H), 5.68 (dd, J=15, 6 Hz, 1H), 5. 51 (dd,
J=15, 9 Hz, 1H), 4.9–4.6 (m, 1H), 4.44 (s, 2H), 4.42 (q,
J=6 Hz, 1H), 3.96 (q, J=9 Hz, 1H), 3.42 (s, 3H), 3.8–2.6
(br, 3H), 2.90(dd, J=14, 6 Hz, 1H), 2.82 (dd, J=14, 6
Hz, 1H), 2.65–2.2 (m, 7H), 2.1–1.5 (m, 7H); MS (APCI)
m/z: 439 (MꢂH)ꢂ; HRMS (MALDI-TOF) calcd for
C23H33FO5S+Na+: 463.1930; found: 463.1965.
16-(3-Methoxymethyl)phenyl-5-thia-!-tetranorPGF1
methyl ester 11,15-bis(tetrahydropyranyl) 47. Prepara-
tion of 47 was accomplished by another method, which
was required for the synthesis of several 5-thiaPGE1
derivatives from THP-lactone. The details of this newly
discovered method for large-scale synthesis will be
1
reported in due course. H NMR (300 MHz, CDCl3): d
7.3–7.1 (m, 4H), 5.65–5.3 (m, 2H), 4.75–4.45 (m, 2H),
4.43 and 4.42 (s, 2H), 4.3–3.7 (m, 4H), 3.67 (s, 3H), 3.5–
3.4 and 3.3–3.2 (m, 2H), 3.38 (s, 3H), 3.0–2.7 (m, 2H),
2.6–2.1 (m, 7H), 2.0–1.4 (m, 17H).
16-(3-Methoxymethyl)phenyl-9-O-mesyl-5-thia-!-tetra-
norPGF1 methyl ester 11,15-bis(tetrahydropyranyl) 48a.
To a stirred solution of 47 (630mg, 1.0mmol) and
triethylamine (0.21 mL, 1.5 mmol) in CH2Cl2 (5 mL)
was added methanesulfonyl chloride (0.093 mL, 1.2
mmol) at 0 ꢁC. The reaction mixture was stirred for 30
min, diluted with ether, and successively washed with
water, 1 N HCl, aqueous NaHCO3 and brine, and dried
(Na2SO4). The solvent was removed by evaporation to
give crude 48a, which was used for the next reaction
without further purification.
Prostanoid EP and IP receptor binding assay
Membranes from CHO cells expressing prostanoid
receptors were incubated with radioligand (2.5 nM of
3
[3H]PGE2 for EP1-4 or 5.0nM of [ H]Iloprost for IP)
and the test compounds at various concentrations in
assay buffer [10mM Kpi (KH PO4, KOH; pH 6.0), 1
2
mM EDTA and 0.1 mM NaCl, for EP1–4-receptors; 50
mM Tris–HCl (pH 7.5), 1 mM EDTA and 10mM
MgCl2 for IP-receptor]. Incubation was carried out at
25 ꢁC for 60min except for EP1 (20min) and IP (30
min) receptors. The incubation was terminated by fil-
tration through Whatman GF/B filters. The filters were
then washed with ice-cold buffer [10mM Kpi (KH 2PO4,
KOH; pH 6.0), 0.1 mM NaCl for EP1-4; 10 mM Tris–
HCl (pH 7.5), 0.1 mM NaCl for IP], and the radioactivity
on the filter was measured in 6mL of liquid scintillation
(ACSII) mixture with a liquid scintillation counter.
Nonspecific binding was determined by incubation of 10
9ꢀ-Fluoro-9-deoxy-16-(3-methoxymethyl)phenyl-5-thia-
!-tetranorPGF1 methyl ester 11,15-bis(tetrahydropyra-
nyl) 49a. A mixture of crude 48a and anhydrous tetra-
butylammonium fluoride (prepared by concentration of
1.0M THF solution, 0.30 g, 1.16 mmol) in anhydrous
toluene (6.0mL) was stirred at 55 ꢁC for 1 h. The reac-
tion mixture was cooled to room temperature, then
poured into water and extracted with EtOAc. The
organic layer was washed with water and brine, and dried
(Na2SO4). The solvent was removed by evaporation to

T. Maruyama et al. / Bioorg. Med. Chem. 10 (2002) 1743–1759
1759
mM unlabeled PGE2 (for EP1-4) or 1 mM unlabeled
Iloprost (for IP) with assay buffer.
References and Notes
1. (a) Takahashi, S.; Takeuchi, K.; Okabe, S. Biochem. Phar-
macol. 1999, 58, 1997. (b) Quiroga, J.; Prieto, J. Pharmacol.
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2. Shinomiya, S.; Naraba, H.; Ueno, A.; Utsunomiya, I.;
Maruyama, T.; Ohuchida, S.; Ushikubi, F.; Yuki, K.; Nar-
umiya, S.; Sugimoto, Y.; Ichikawa, A.; Oh-ishi, S. Biochem.
Pharmacol. 2001, 61, 1153.
3. Maruyama, T., Asada, M., Shiraishi, T., Ishida, A., Yosh-
ida, H., Maruyama, T., Ohuchida, S., Nakai, H., Kondo, K.,
Toda, M. Bioorg. Med. Chem. Submitted for publication
4. Kawaguchi, T.; Suzuki, Y. J. Pharm. Sci. 1986, 75, 992.
5. Ishihara, K.; Kurihara, H.; Yamamoto, H. J. Org. Chem.
1993, 58, 3791.
6. Corey, E. J.; Fuchs, P. L. Tetrahedron Lett. 1972, 3769.
7. Dygos, J. H.; Adamek, J. P.; Babiak, K. A.; Behling, J. R.;
Medich, J. R.; Ng, J. S.; Wieczorek, J. J. J. Org. Chem. 1991,
56, 2549.
Measurement of cAMP production
Chinese hamster ovary (CHO) cells expressing EP4-
receptor were cultured in 24-well plates (1ꢄ105 cells/
well). After 2 days, the medium was removed and cells
were washed with 500 mL of Minimum Essential Med-
ium (MEM) and pre-incubated for 10min in 450 mL
of assay buffer (MEM containing 1 mM of IBMX,
1% of BSA) at 37 ꢁC. Then, the reaction was started
with the addition of each test compound in 50 mL of
assay buffer. After incubation for 10min at 37 ꢁC, the
reaction was terminated by addition of 500 mL of ice-
cold 10% trichloroacetic acid. cAMP production was
measured by radio-immunoassay using a cAMP assay
kit (Amersham).
8. Kusuda, S.; Watanabe, Y.; Ueno, Y.; Toru, T. Tetrahedron
Lett. 1991, 32, 1325.
9. Tanaka, T.; Okamura, N.; Bannai, K.; Hazato, A.;
Sugiura, S.; Manabe, K.; Kamimoto, F.; Kurozumi, S. Chem.
Pharm. Bull. 1985, 33, 2359.
10. Suzuki, M.; Yanagisawa, A.; Noyori, R. J. Am. Chem.
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11. Okamoto, S.; Katayama, S.; Ono, N.; Sato, F. Tetra-
hedron: Asymmetry 1992, 3, 1525.
12. Arroniz, C. E.; Gallina, J.; Martinez, E.; Muchowski,
J. M.; Velarde, E.; Rooks, W. H. Prostaglandins 1978, 16, 47.
13. Kiriyama, M.; Ushikubi, F.; Kobayashi, T.; Hirata, M.;
Sugimoto, Y.; Narumiya, S. Br. J. Pharmacol. 1997, 122, 217.
14. Maruyama, T.; Asada, M.; Shiraishi, T.; Sakata, K.; Seki,
A.; Yoshida, H.; Shinagawa, Y.; Maruyama, T.; Ohuchida, S.;
Nakai, H.; Kondo, K.; Toda, M. Bioorg. Med. Chem. Lett.
2001, 11, 2033.
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gawa, Y., Maruyama, T., Kondo, K., Ohuchida, S. Abstract
Book, 11th International Conference on Advances in Prosta-
glandin and Leukotriene Research, Florence, Italy, June 4–8,
2000.
Measurement of intracellular Ca2+ production
Intracellular Ca2+ concentration was measured using a
Jasco CAM220Spectrofluorometer. Chinese hamster
ovary (CHO) cells expressing EP3-receptor were cul-
tured for 2 days. After the medium was removed, the
cells were washed with PBS and centrifuged at 800
rpm for 3 min. The cells were incubated at 37 ꢁC for
60min with fura 2-AM in conditioned medium con-
sisting of MEM containing 20 mM indomethacin,
10% FCS and 10 mM HEPES–NaOH (pH 7.4). The
medium containing the cells was centrifuged at 800 rpm
for 3 min and the cells were suspended in assay buffer
consisting of MEM containing 2 mM indomethacin,
0.1% BSA and 10 mM HEPES–NaOH (pH 7.4). The
test compound was added to the suspension of the cells
with stirring. Intracellular Ca2+ production was calcu-
lated from the ratio of the fluorescence intensities at
340and 380nm.