Synthesis of (±)-15-deoxy-Δ12,14-prostaglandin J2 and Δ12-prostaglandin J2 15-acetate methyl esters

Article abstract of DOI:10.1134/S1070428015010017

A new synthetic approach to 15-deoxy-Δ^12,14-prostaglandin J₂ and related compounds starting from Corey (±)-lactone diol has been developed. The key stage of this approach includes synthesis of a prostaglandin derivative possessing le

Full text of DOI:10.1134/S1070428015010017

ISSN 1070-4280, Russian Journal of Organic Chemistry, 2015, Vol. 51, No. 1, pp. 1–9. © Pleiades Publishing, Ltd., 2015.
Original Russian Text © N.S. Vostrikov, I.F. Lobko, D.U. Ishimova, M.S. Miftakhov, 2015, published in Zhurnal Organicheskoi Khimii, 2015, Vol. 51, No. 1,
pp. 9–16.
Synthesis of (±)-15-Deoxy-Δ12,14-prostaglandin J2
and Δ12-Prostaglandin J2 15-Acetate Methyl Esters
N. S. Vostrikova, I. F. Lobkoa, D. U. Ishimovab, and M. S. Miftakhova
a Institute of Organic Chemistry, Ufa Research Center, Russian Academy of Sciences,
pr. Oktyabrya 71, Ufa, 450054 Bashkortostan, Russia
e-mail: bioreg@anrb.ru
b Bashkir State University, ul. Zaki Validi 32, Ufa, 450074 Bashkortostan, Russia
Received July 1, 2014
Abstract—A new synthetic approach to 15-deoxy-Δ12,14-prostaglandin J2 and related compounds starting from
Corey (±)-lactone diol has been developed. The key stage of this approach includes synthesis of a prostaglandin
derivative possessing leaving groups in positions 9, 13, and 15 and their subsequent elimination by the action
of an organic base.
DOI: 10.1134/S1070428015010017
Δ
12,14-PGJ2; however, only a few syntheses of com-
Among cyclopentenone prostaglandins (PG), of
particular interest are products of albumin-cata-
lyzed dehydration of prostaglandin D2 (PGD2),
highly electrophilic Δ12-PGJ2 (1) and 15-deoxy-
pounds 1 and 2 have been reported [8–11]. In par-
ticular, a procedure for their preparation from PGF2α
was patented [12].
Δ
12,14-PGJ2 (2) [1]. Unlike other prostaglandins, com-
In this article we describe a new synthetic ap-
proach to structures related to 1 and 2. Here, the key
stage is the synthesis of differently protected prosta-
glandin F derivatives 3 where the R1 group protecting
the C11–OH group can be selectively removed without
involving the other protecting groups. Naturally, the
protecting groups R2–R4 should be readily leaving
groups, such as acetate, toluenesulfonate, methane-
sulfonate, carbonate, etc. In the next stage, ketone 4
obtained by oxidation of the C11–OH group should
undergo stepwise decomposition, eventually leading to
target prostaglandin 5 (Scheme 1).
pounds 1 and 2 contain cross-conjugated di- and triene
fragments that are responsible for their biological
properties [2, 3]. The anticarcinogenic activity of
Δ12-PGJ2 (1) and Δ7-PGA1 is related to their ability to
be reversibly transferred through cell membranes and
inside cells. These compounds inhibit cellular
processes via covalent binding to nuclear proteins [4].
Another important representative of diene prosta-
glandins, 15-deoxy-Δ12,14-PGJ2 (2), is known as a se-
lective ligand for PPARγ (peroxisome proliferator-
activated receptor γ), a member of nuclear receptors
that directly regulate gene transcription and are
responsible for triggering of inflammation, apoptosis,
virus replication inhibition, etc. [5–7]. There are many
publications on the biological properties of 15-deoxy-
One compound like 3 was synthesized using
standard methods of the prostaglandin chemistry [13].
The starting compound was Corey (±)-lactone diol 6
[14]. Lactone 8 was obtained according to the previ-
COOH
COOH
Me
Me
O
O
HO
1
2
1

VOSTRIKOV et al.
2
ously tested scheme [15] via selective protection of the
primary hydroxy group in diol 6 with tert-butyldi-
phenylsilyl group, followed by protection of the sec-
ondary hydroxy group in 7 by tetrahydropyran-2-yl
(THP) moiety (Scheme 2). Lactone 8 was then used to
build up the upper prostaglandin chain according to
Wittig. For this purpose, compound 8 was prelimi-
narily reduced to lactol 9, and the latter was subjected
to olefination with the phosphonium ylide generated
from triphenylphosphine and 5-bromopentanoic acid.
Crude hydroxy acid 10 was alkylated with diazometh-
ane, and hydroxy ester 11 was acetylated to obtain
acetoxy ester 12. Attempted purification of acid 10 by
silica gel column chromatography was accompanied
by removal of the THP protection with formation of
dihydroxy acid 13. Presumably, intramolecular assis-
tance of the “free” carboxy group favors hydrolysis of
the THP ether moiety. For identification purpose,
dihydroxy acid 13 was methylated, and ester 14 was
acetylated; as a result, diacetate 15 was isolated.
The construction of the lower side chain (ω-chain)
was started from selective desilylation of 12 by the ac-
tion of tetrabutylammonium fluoride. Alcohol 16 thus
obtained was oxidized with Collins reagent to unstable
aldehyde 17 whose chromatographic purification (as
well as storage) was accompanied by formation of
small amounts of aldehyde 18 and isomeric com-
pounds. The condensation of 17 with dimethyl 2-oxo-
heptylphosphonate smoothly afforded 80% of enone
19 (Scheme 3). It seemed reasonable to use enone 19
Scheme 1.
COOMe
COOMe
COOMe
R2O
R1O
R2O
Me
Me
Me
O
O
R3
R3
R4O
R4O
3
4
5
R1–R4 are protecting groups (see text).
Scheme 2.
O
O
O
OH
O
O
i, ii
iii
HO
RO
THPO
OH
OSiPh2Bu-t
7, 8
OSiPh2Bu-t
( )-6
9
RO
COOMe
v, vi
OSiPh2Bu-t
HO
COOH
THPO
HO
iv
11, 12
OSiPh2Bu-t
AcO
AcO
COOR
COOMe
THPO
v, vi
vii, v
10
OSiPh2Bu-t
13, 14
OSiPh2Bu-t
HO
15
7, 11, 13, R = H; 8, R = THP; 12, R = Ac; 14, R = Me; i: t-BuPh2SiCl (1.2 equiv), imidazole, CH2Cl2; ii: dihydropyran, CH2Cl2,
pyridine–TsOH; iii: i-Bu2AlH, CH2Cl2, –70°C; iv: Br–Ph3P+(CH2)4CO2H, Me6Si2NNa, THF; v: CH2N2; vi: Ac2O–pyridine; vii: SiO2.
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 51 No. 1 2015

SYNTHESIS OF (±)-15-DEOXY-Δ12,14-PROSTAGLANDIN J2
3
Scheme 3.
AcO
AcO
COOMe
COOMe
i
OSiPh2Bu-t
OH
THPO
THPO
AcO
12
16
AcO
COOMe
COOMe
ii
+
CHO
17
CHO
18
THPO
AcO
AcO
THPO
AcO
COOMe
COOMe
iii
iv
vii, viii
x
17
Me
Me
THPO
AcO
R
O
O
19
20
COOMe
COOMe
v, vi
Me
Me
THPO
RO
EtS
EtSO2
RO
OAc
21, 22
23, 24
AcO
O
COOMe
COOMe
ix
Me
Me
O
EtSO2
OAc
25
5
COOMe
xi
21
Me
O
AcO
26
i: Bu4NF, THF; ii: CrO3 · 2 Py, CH2Cl2; iii: (MeO)2P(O)CH2C(O)C5H11, NaOH–H2O, CH2Cl2, Bu4N+Br–; iv: EtSH, THF, NaH;
v: NaBH4, MeOH, 0°C; vi: Ac2O–pyridine; vii: 30% H2O2–(NH4)6Mo7O24 ·7H2O; viii: 30% AcOH, 60°C; ix: PCC, CH2Cl2; x: DBU,
PhH, 20°C; xi: H2CrO4–Me2CO–H2O; 20, R = EtS; 21, 24, R = Ac; 22, R = H; 23, R = THP.
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 51 No. 1 2015

VOSTRIKOV et al.
4
as building block for the introduction of C13-leaving
group via Michael reaction.
Analytical TLC was performed on Sorbfil plates
(Russia).
(±)-(3aR*,4S*,5R*,6aS*)-4-{[tert-Butyl(diphe-
nyl)silyloxy]methyl}-5-hydroxyhexahydro-2H-
cyclopenta[b]furan-2-one (7). Imidazole, 3.1 g
(45.6 mmol), was added under stirring to a suspension
of 3.57 g (20.7 mmol) of racemic lactone diol (±)-6 in
150 mL of anhydrous methylene chloride, a solution of
6.26 g (22.77 mmol) of tert-butyl(chloro)diphenyl-
silane in 50 mL of anhydrous methylene chloride
was slowly added, and the mixture was stirred for 6 h
until compound 6 disappeared (TLC). The organic
phase was washed with water and brine and evaporated
under reduced pressure, and the residue was purified
by silica gel chromatography using petroleum ether–
ethyl acetate (4:1) as eluent. Yield 5 g (85%), colorless
crystals, mp 92–97°C, Rf 0.22 (petroleum ether–ethyl
acetate, 7:3). IR spectrum, ν, cm–1: 3456, 3070, 1749,
1458, 1375, 1357, 1114, 1033, 707. 1H NMR spectrum
(CDCl3), δ, ppm: 1.05 s (9H, t-BuSi), 1.98 m (2H, 4-H,
endo-6-H), 2.10 br.s (1H, OH), 2.40 m (2H, endo-3-H,
exo-6-H), 2.58 m (1H, 3a-H), 2.69 d.d (1H, exo-3-H,
J = 17.7, 9.9 Hz), 3.61 d.d (1H, CH2O, J = 10.5,
6.7 Hz), 3.71 d.d (1H, CH2O, J = 10.5, 5.2 Hz),
4.17 m (1H, 5-H), 4.87 t.d (1H, 6a-H, J = 6.9, 2.9 Hz),
7.42 m (6H, Ph), 7.63 d (4H, Ph, J = 6.0 Hz). 13C NMR
spectrum (CDCl3), δC, ppm: 19.06 (SiCMe3), 26.80
(SiCMe3), 35.21 (C3), 39.34 (C3a), 40.54 (C6), 55.30
(C4), 64.18 (CH2O), 74.95 (C5), 83.65 (C6a), 127.78
(Cm), 129.90 (Cp), 132.79 (Ci), 135.44 (Co), 177.20
(C2). Mass spectrum, m/z (Irel, %): 411 (20.6) [M + H]+,
393 (5.9) [M – H2O]+, 365 (82.4), 333 (100)
[M – PhH]+. Calculated: M 410.58.
Taking into account the ease of base-catalyzed ad-
dition of thiols to enones, enone 19 was brought into
1,4-conjugate addition reaction with ethanethiol in
THF. The reaction was catalyzed by sodium hydride,
and it rapidly produced adduct 20 in a high yield. In
the next step, the substituents on C13 and C15 in 20
were converted into readily leaving groups. The sim-
plest and most convenient version involved trans-
formation of the sulfide moiety into sulfone and of
the oxo group into acetate. For this purpose, ketone 20
was reduced to alcohol 21 in high yield with NaBH4 in
methanol at 0°C, and alcohol 21 was acylated and
oxidized with H2O2 in the presence of Mo(VI) salt to
obtain sulfone 23. Removal of the THP protection
from 23, followed by oxidation of alcohol 24 with
pyridinium chlorochromate gave ketone 25. We failed
to deprotect the latter under acidic conditions. Ketone
25 remained unchanged after heating for 30 min in
boiling benzene containing an equivalent amount of
benzoic acid, but it was smoothly converted into
compound 5 in benzene in the presence of DBU at
room temperature. The progress of the reaction was
monitored by TLC, and we thus succeeded in detecting
two by-products whose structure was not determined
because of too small amount of the isolated samples.
An apparently chemorational version involving gen-
eration in situ of the 11-hydroxy function and sulfonyl
group on C13 directly from THP ether 22 via oxidation
with Jones reagent was successful only partly, and
Δ12-PGJ2 derivative 26 was isolated in a moderate yield.
In summary, we have developed a synthetic ap-
proach to (±)-15-deoxy-∆12,14-prostaglandin J2 methyl
ester on the basis of accessible building blocks that are
conventional for prostaglandin chemistry, Corey lac-
tone diol 5 and 15-oxoprostadienoic acid derivative 19.
The proposed approach can be implemented in a chiral
version and is adaptable for the synthesis of analogs.
(±)-(3aR*,4S*,5R*,6aS*)-4-{[tert-Butyl(diphe-
nyl)silyloxy]methyl}-5-(tetrahydro-2H-pyran-2-
yloxy)hexahydro-2H-cyclopenta[b]furan-2-one (8).
Freshly distilled dihydropyran, 2.2 g (26.18 mmol),
was added dropwise under stirring to a solution of 5 g
(17.45 mmol) of alcohol 7 in 60 mL of anhydrous
methylene chloride, 0.49 g of pyridinium p-toluene-
sulfonate was then added, and the mixture was stirred
until the reaction was complete (TLC). The mixture
was washed with water and brine and evaporated under
reduced pressure, and the residue was purified by
chromatography. Yield 6.2 g (95%), colorless oily
material, Rf 0.75 (petroleum ether–ethyl acetate, 1:1).
IR spectrum, ν, cm–1: 2938, 2932, 1774, 1472, 1428,
EXPERIMENTAL
The IR spectra were recorded from thin films on
1
a Shimadzu IR Prestige-21 spectrometer. The H and
13C NMR spectra were measured on a Bruker AM-300
spectrometer at 300.13 and 75.47 MHz, respectively,
using the solvent signals (CHCl3) as reference.
The mass spectra (electron impact, 70 eV) were
obtained on a Thermo Finnigan MAT 95XP in-
strument (ion source temperature 200°C, batch inlet
probe temperature 60–280°C at a rate of 22 deg/min).
1
1112. H NMR spectrum (CDCl3), δ, ppm (mixture of
diastereoisomers at a ratio of 1:1): 1.05 s (9H, t-Bu),
2.75 m (2H, 3-H), 3.40–3.90 m (4H, CH2O), 4.10 m
and 4.25 m (0.5H each, 5-H), 4.55 m and 4.65 m (0.5H
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 51 No. 1 2015

SYNTHESIS OF (±)-15-DEOXY-Δ12,14-PROSTAGLANDIN J2
5
each, 2′-H), 4.90 m (6a-H), 7.40 m (6H) and 7.70 m
(4H) (C6H5). 13C NMR spectrum, (CDCl3), δC, ppm:
19.10 (SiCMe3), 19.26 (C4′), 25.36 (C5′), 26.79
(SiCMe3), 30.50 and 30.68 (C3′), 35.48 and 35.78 (C3),
36.32 and 39.19 (C6), 38.81 and 39.65 (C3a), 54.20 and
55.37 (C4), 62.07 (CH2OSi), 63.01 and 63.88 (C6′),
77.13 and 79.47 (C5), 84.07 and 84.48 (C6a), 95.52 and
98.58 (C2′); 127.74, 129.84, 133.02, 135.48 (C6H5);
177.03 and 177.35 (C2).
the extract was washed with water (20 mL) and
brine (30 mL), dried over MgSO4, and evaporated
on a rotary evaporator. The residue (crude acid 10) was
treated with excess diazomethane in diethyl ether, and
methyl ester 11 was isolated by silica gel column
chromatography. Yield 5.3 g (75%, calculated on lac-
tol 9), colorless viscous oily material, Rf 0.7 (petro-
leum ether–ethyl acetate, 1:1). IR spectrum, ν, cm–1:
1
3527, 2933, 1739, 1429, 1113, 703, 565. H NMR
spectrum (CDCl3), δ, ppm: 0.92 s and 0.94 s (9H,
t-Bu), 2.20 m (2H), 3.30–3.40 m (2H), 3.45 d.d (1H,
J = 5.1, 10.2 Hz) and 3.60 d.d (1H, J = 4.1, 10.3 Hz)
(CH2OSi), 3.54 s (3H, OCH3), 3.70 m (1.5H) and
3.80 m (0.5H), 4.00 m (2H, 5″-H), 4.25 m (1H, 3′-H),
4.59 m (0.5H) and 4.63 m (0.5H) (2″-H), 5.20–5.35 m
Methyl (±)-(5Z)-7-[(1R*,2S*,3R*,5S*)-2-{[tert-
butyl(diphenyl)silyloxy]methyl}-5-hydroxy-3-
(tetrahydro-2H-pyran-2-yloxy)cyclopentyl]hept-
5-enoate (11). A solution of 6.2 g (12.5 mmol) of lac-
tone 8 in 250 mL of anhydrous methylene chloride was
cooled to –78°C, a solution of 8.7 mL (43.8 mmol) of
i-Bu2AlH in 30 mL of methylene chloride was added
dropwise under stirring in an argon atmosphere,
the mixture was stirred for 45 min at –78°C, 8.6 mL of
methanol was added dropwise, and the mixture was
allowed to gradually warm up to room temperature.
Water, 50 mL, was then added, the mixture was stirred
for 2 h, the precipitate was filtered off and washed
with methylene chloride (3×10 mL), and the filtrate
was combined with the washings, dried over MgSO4,
and evaporated on a rotary evaporator. The residue was
treated with 30 mL of anhydrous benzene, the mixture
was evaporated, and the residue was dried under
reduced pressure (1 mm) for 30 min to isolate 5.9 g of
colorless oily lactol 9 which was used in the next step
without additional purification.
13
(2H, CH=CH). C NMR spectrum (CDCl3), δC, ppm:
19.17 and 19.78 (C4″, SiCMe3), 24.77 (C3), 25.30
(C5″), 26.50 (C7), 27.04 (C6), 26.77 (SiCMe3), 30.66
and 31.20 (C3″), 33.39 (C2), 39.25 and 40.85 (C4′),
46.53 and 46.75 (C2′), 51.30 (OCH3), 52.47 and 52.89
(C1′), 61.99 and 63.94 (CH2OSi), 63.94 and 64.57
(C6″), 74.79 and 75.01 (C5′), 79.72 and 80.87 (C3′),
96.54 and 97.56 (C2″), 127.59, 129.14 and 129.45,
129.60, 133.35 and 133.40 (Ci), 135.50 (CH=CH,
C6H5), 174.01 (C=O).
Methyl (±)-(5Z)-7-{(1R*,2S*,3R*,5S*)-5-acet-
oxy-2-[tert-butyl(diphenyl)silyloxymethyl]-3-
(tetrahydro-2H-pyran-2-yloxy)cyclopentyl}hept-
5-enoate (12). Freshly distilled acetic anhydride,
4.8 mL (51 mmol), was added dropwise under stirring
at 0°C to a solution of 5 g (8.4 mmol) of compound 11
and 0.07 g (0.56 mmol) of 4-dimethylaminopyridine
(DMAP) in 40 mL of anhydrous pyridine. When
the reaction was complete (TLC), the mixture was
diluted with 50 mL of water and extracted with
methylene chloride (3 × 40 mL). The extract was
washed with water (2 × 20 mL) and brine (20 mL),
dried over MgSO4, and evaporated under reduced
pressure, and the residue was purified by silica gel
chromatography. Yield 4.44 g (83%), oily material,
Rf 0.65 (petroleum ether–ethyl acetate, 7:3). IR spec-
trum, ν, cm–1: 2933, 2856, 1732, 1427, 1373, 1244,
Sodium hexamethyldisilazide, 20.2 g (110 mmol),
was added in portions under stirring at 0°C in an argon
atmosphere to a suspension of 24.38 g (55 mmol) of
triphenylphosphonium 5-bromopentanoate in 90 mL
of anhydrous THF, and the mixture was allowed to
warm up to room temperature and stirred for 0.5 h
more. A solution of 5.9 g (11.9 mmol) of lactol 9 (see
above) in 30 mL of THF was added to the red–orange
solution of phosphonium ylide, and the mixture was
stirred for 1 h. A solution of 1 g of potassium carbon-
ate in 60 mL of water, 35 mL of diethyl ether, 35 mL of
ethyl acetate, and 70 mL of benzene were then added,
and the mixture was thoroughly stirred and allowed
to settle down. The aqueous layer was extracted
with diethyl ether–ethyl acetate (1:1, 3×50 mL), and
the extracts were combined with the organic phase and
washed with water (3 ×50 mL). The aqueous frac-
tions were combined, cooled to 3–5°C, and acidified
to pH ~6 with a saturated solution of sodium hydro-
gen sulfate under stirring. Acid 10 was extracted from
the aqueous phase into ethyl acetate (3×50 mL), and
1
1111, 1022, 704. H NMR spectrum (CDCl3), δ, ppm:
1.05 s (9H, t-Bu), 2.03 s (3H, CH3), 2.20 t (2H, 2-H,
J = 7.5 Hz), 3.64 s (OCH3), 3.65–3.90 m (4H), 4.10 m
and 4.30 m (0.5H each, 3′-H), 4.45 m and 4.55 m
(0.5H each, 2″-H), 5.09 m (1H, 5′-H), 5.33 m (2H,
CH=CH). 13C NMR spectrum (CDCl3), δC, ppm: 19.35
and 19.54 (C4″, SiCMe3), 21.33 (CH3), 24.81 (C3),
25.47(C5″), 26.62 (C4), 25.71 (C7), 26.92 (SiCMe3),
31.11 (C3″), 33.47 (C2), 37.85 and 39.61 (C4′), 42.55
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 51 No. 1 2015

VOSTRIKOV et al.
6
and 43.27 (C1′), 51.45 (OCH3), 52.12 (C2′), 62.26
(CH2OSi), 62.86 (C6″), 75.19 and 79.04 (C3′), 76.18
and 76.36 (C5′), 97.02 and 99.80 (C2″), 127.67, 129.73
and 129.64, 133.47 and 133.55, 135.65 (C6H5), 128.74,
128.79 and 129.47, 129.73 (CH=CH), 170.76 and
170.91 (MeCO), 173.97 (CO2Me).
(CH2OSi), 74.99 and 75.22 (C3′), 78.92 and 79.04
(C5′), 98.53 and 99.09 (C2″), 128.17, 128.86 and
129.55 (CH=CH), 170.68 (MeCO), 173.94 and 174.00
(CO2Me).
Methyl (±)-(5Z)-7-[(1R*,2R*,3R*,5S*)-5-acet-
oxy-3-(tetrahydro-2H-pyran-2-yloxy)-2-formyl-
cyclopentyl]hept-5-enoate (17). A solution of 2 g
(5 mmol) of alcohol 16 in 50 mL of anhydrous meth-
ylene chloride was cooled to 0°C, a solution of
the CrO3–pyridine complex prepared from 3.62 g
(36.2 mmol) of chromium(VI) oxide and 56.8 mL of
anhydrous pyridine in 50 mL of anhydrous methylene
chloride was added in one portion, and the mixture was
stirred for 1 h and filtered through 30 cm3 of silica gel.
The sorbent was washed with methylene chloride
(3×30 mL), and the washings were combined with
the filtrate and evaporated under reduced pressure.
Yield 1.8 g (90%), colorless oily substance, Rf 0.6
Methyl (±)-(5Z)-7-{(1R*,2S*,3R*,5S*)-3,5-diacet-
oxy-2-[tert-butyl(diphenyl)silyloxymethyl]cyclo-
pentyl}]hept-5-enoate (15). Chromatographic puri-
fication of a sample of hydroxy acid 10 on silica gel
was accompanied by removal of the THP protecting
group with formation of dihydroxy acid 13 which was
identified as oily diacetoxy ester 15, Rf 0.6 (petroleum
ether–ethyl acetate, 7:3). IR spectrum, ν, cm–1: 2953,
2932, 1735, 1466, 1428, 1240, 1112, 1106, 703.
1H NMR spectrum (CDCl3), δ, ppm: 1.03 s (9H, t-Bu),
1.95 s and 2.08 s (3H each, OAc), 2.28 t (2H, CH2, J =
7.6 Hz), 3.62 s (3H, OCH3), 5.10 br.s (1H, 5′-H),
5.20 br.s (1H, 3′-H), 5.35 m (2H, CH=CH), 7.30 m
(6H) and 7.65 m (4H) (C6H5). 13C NMR spectrum
(CDCl3), δC, ppm: 19.31 (SiCMe3), 21.18 and 21.25
(MeCO), 24.75 (C3), 25.60 (C7), 26.68 (C4), 26.86
(SiCMe3), 33.43 (C2), 38.97 (C4′), 43.42 (C1′), 51.50
(OMe, C2′), 62.12 (CH2OSi), 76.05 (C3′, C5′), 127.72,
129.75, 133.23, 133.38, 135.60, 135.64 (C6H5),
128.34, 129.00 (CH=CH), 170.58 and 170.68 (MeCO),
173.94 (CO2Me).
1
(petroleum ether–ethyl acetate, 1:1). H NMR spec-
trum (CDCl3), δ, ppm: 2.00 s (3H, OAc), 2.25 t (2H,
2-H, J = 7.1 Hz), 3.60 s (3H, OCH3), 4.45 m (1H,
3′-H), 4.50 br.s and 4.55 br.s (1H, 2″-H), 5.05 m (1H,
5′-H), 5.25–5.40 m (2H, CH=CH), 9.80 d (1H, CHO,
J = 2.6 Hz). 13C NMR spectrum (CDCl3), δC, ppm:
21.06 (CH3), 51.35 (OCH3), 98.38 and 99.13 (C2″),
127.37; 127.54, 130.43, 130.62 (CH=CH); 170.12
and 170.37 (MeCO), 173.78 (CO2Me), 201.86 and
202.38 (CHO).
Methyl (±)-(5Z)-7-[(1R*,2S*,3R*,5S*)-5-acetoxy-
2-hydroxymethyl-3-(tetrahydro-2H-pyran-2-yloxy)-
cyclopentyl]hept-5-enoate (16). A solution of 4 g
(6.28 mmol) of silyl ether 12 in 50 mL of THF was
cooled to 0°C, 12.65 mL of a 1 M solution of tetra-
butylammonium fluoride in THF was added over
a period of 3 min, and the mixture was stirred until
the reaction was complete (TLC). The mixture was
diluted with 100 mL of ethyl acetate, washed with
water (3 × 50 mL) and brine (30 mL), dried over
MgSO4, and evaporated under reduced pressure, and
the residue was purified by silica gel chromatography.
Yield 2.13 g (85%), colorless oily material, Rf 0.65
Methyl (±)-(5Z)-7-[(5S*)-5-acetoxy-2-formyl-
cyclopent-2-en-1-yl]hept-5-enoate (18) was isolated
as by-product in the chromatographic purification of
1
aldehyde 17. H NMR spectrum (CDCl3), δ, ppm:
1.98 s (3H, OAc), 3.60 s (3H, OCH3), 6.75 br.s (1H,
3′-H), 9.65 s (1H, CHO). 13C NMR spectrum (CDCl3),
δC, ppm: 127.84 and 129.84 (CH=CH), 147.50 (C2′),
149.05 (C3′), 189.15 (CHO).
Methyl (±)-(5Z,9α,11α,13E)-9-acetoxy-15-oxo-11-
(tetrahydro-2H-pyran-2-yloxy)prosta-5,13-dien-
1-oate (19). Aldehyde 17, 1.8 g (4.54 mmol), was
dissolved in 100 mL of anhydrous methylene chloride,
1 g (4.54 mmol) of dimethyl 2-oxoheptylphospho-
nate, 0.05 g of tetraethylammonium bromide, and
0.4 mL of 50% aqueous sodium hydroxide were added
under vigorous stirring, and the mixture was stirred
until the reaction was complete (6 h, TLC). The mix-
ture was washed with water (2×30 mL) and brine
(20 mL), dried over MgSO4, and evaporated under
reduced pressure, and the residue was purified by silica
gel chromatography. Yield 1.79 g (80%), colorless oily
material, Rf 0.7 (petroleum ether–ethyl acetate, 1:1).
1
(petroleum ether–ethyl acetate, 7 : 3). H NMR spec-
trum (CDCl3), δ, ppm: 2.03 s (3H, CH3), 2.30 m (2H),
3.65 s (3H, OCH3), 4.10 m (0.6H) and 4.35 m (0.4H)
(3′-H), 4.55 m (0.4H) and 4.70 m (0.6H) (OCHO),
5.30 m (0.4H) and 5.60 m (0.6H) (5′-H), 5.35 m (2H,
CH=CH). 13C NMR spectrum (CDCl3), δC, ppm: 19.51
and 20.08 (C4″), 21.04 (CH3), 24.52 (C3), 25.05 and
25.18 (C5″), 25.41 and 25.53 (C7), 26.34 (C4), 30.72
and 31.02 (C3″), 33.18 (C2), 38.09 and 39.24 (C4′),
43.09 and 43.42 (C1′), 51.33 and 51.45 (C2′), 51.38
(OCH3), 62.35 and 62.56 (C6″), 62.89 and 63.52
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SYNTHESIS OF (±)-15-DEOXY-Δ12,14-PROSTAGLANDIN J2
7
IR spectrum, ν, cm–1: 2950, 2934, 1735, 1700, 1680 w,
1620, 1242. H NMR spectrum (CDCl3), δ, ppm:
was complete, 40 mL of water was added, methanol
was distilled off, and the mixture was extracted with
methylene chloride (4×30 mL). The combined extracts
were washed with brine, dried over MgSO4, and evap-
orated under reduced pressure, and the residue was
purified by silica gel chromatography. Yield 1.35 g
(90%), colorless oily material, Rf 0.45 (petroleum
1
0.85 t (3H, CH3, J = 6.9 Hz), 2.00 s and 2.01 s (3H,
OAc), 2.22 t (2H, CH2, J = 6.9 Hz), 2.50 t (2H, CH2,
J = 7.1 Hz), 3.60 s (3H, OCH3), 4.05 m (1H, 11-H),
4.50 br.s (0.5H) and 4.55 br.s (0.5H, 2″-H), 5.00 br.s
(1H, 9-H), 5.30 m (2H, CH=CH), 6.18 d.t (1H,
14-H, J = 1.7, 15.9 Hz), 6.68 m (1H, 13-H). 13C NMR
spectrum (CDCl3), δC, ppm: 13.88 and 14.14 (CH3),
19.01 and 19.60 (C4″), 21.18 and 21.19 (MeCO),
22.43 (C19), 23.92 and 23.95 (C17), 24.62 (C3), 25.02
and 25.07 (C5″), 25.27 and 25.33 (C7), 26.55 (C4),
30.66 (C18), 31.40 and 31.42 (C3″), 33.32 (C8), 38.47
and 40.12 (C10), 40.23 and 40.42 (C16), 47.30 and
47.37 (C8), 51.42 (OCH3), 52.99 and 53.54 (C12),
61.69 and 62.68 (C6″), 74.18 and 74.48 (C9), 78.78 and
81.02 (C11), 96.61 and 99.18 (C2″), 127.71 and 127.73
(C6), 130.03 (C14), 131.56 and 131.77 (C5), 146.95
(C13), 170.43 and 170.53 (MeCO), 173.82 (C1), 200.28
and 200.42 (C15).
1
ether–ethyl acetate, 7:3). H NMR spectrum (CDCl3),
δ, ppm: 0.87 t (3H, CH3, J = 6.4 Hz), 1.25 t (3H, CH3,
J = 7.3 Hz), 2.30 t (2H, CH2, J = 7.5 Hz), 2.55 q (2H,
CH2S, J = 6.8 Hz), 3.00 m (1H), 3.45 m (1H, 15-H),
3.65 s (3H, OCH3), 3.75–3.95 m (2.5H, CH2O and
0.5H, 11-H), 4.20 m (0.5H, 11-H), 4.50 br.s and
4.60 br.s (0.5H each, 2″-H), 5.05 m (1H, 9-H),
5.35 br.s (2H, CH=CH). 13C NMR spectrum, (CDCl3),
δC, ppm: 14.02 (CH3), 17.72 and 14.87 (CH3), 19.91
(C4″), 21.22 (CH3), 22.60 (C19), 24.76 (C3), 25.36
(SCH2), 26.68 (C4), 31.05 and 31.29 (C3″), 31.94 (C18),
33.45 (C2), 37.56 and 39.11 (C16), 41.23 and 43.18
(C10), 44.38 and 43.10 (C13), 43.18 and 44.65 (C8),
51.44 (OCH3), 51.90 and 51.79 (C12), 62.86 and 63.20
(C6″), 69.48 and 63.20 (C15), 75.00, 75.41 and 75.67
(C9), 80.12 and 81.13 (C11), 99.08 and 99.52 (C2″),
128.07, 128.31, 129.67 and 129.88 (CH=CH), 170.46
and 170.64 (MeCO), 173.93 (C1).
Methyl (±)-(5Z,9α,11α)-9-acetoxy-15-oxo-13-
ethylsulfanyl-11-(tetrahydro-2H-pyran-2-yloxy)-
prost-5-en-1-oate (20). Sodium hydride, 0.04 g, was
added under stirring in an argon atmosphere to a solu-
tion of 1.44 g (2.92 mmol) of enone 19 and 0.27 g
(4.17 mmol) of ethanethiol in 40 mL of anhydrous
THF. The mixture was stirred for 30 min, 80 mL of
a saturated aqueous solution of ammonium chloride
was added, and the mixture was extracted with meth-
ylene chloride (3×40 mL). The extract was dried over
MgSO4 and evaporated under reduced pressure, and
the residue was purified by silica gel chromatography.
Yield 1.54 g (95%), colorless oily material, Rf 0.6
(petroleum ether–ethyl acetate, 7:3), a mixture of dia-
stereoisomers. IR spectrum, ν, cm–1: 2952, 2929, 1735,
Methyl (±)-(5Z,9α,11α)-9,15-diacetoxy-13-ethyl-
sulfanyl-11-(tetrahydro-2H-pyran-2-yloxy)prost-
5-en-1-oate (22). A solution of 1.35 g (2.43 mmol) of
alcohol 21 and 30 mg of 4-(dimethylamino)pyridine
in 10 mL of anhydrous pyridine was cooled to 0°C,
1.42 mL (14.8 mmol) of acetic anhydride was added
dropwise under stirring, and the mixture was allowed
to warm up to room temperature and stirred for 3 h.
The mixture was cooled again to 5°C, diluted with
20 mL of water, and extracted with methylene chlo-
ride (5×20 mL), the extract was washed with brine
(20 mL) and evaporated under reduced pressure, and
the residue was purified by silica gel chromatography.
Yield 1.42 g (98%), colorless oily material, Rf 0.6
(petroleum ether–ethyl acetate, 7:3). IR spectrum, ν,
cm–1: 2942, 2862, 1736, 1453, 1436, 1373, 1302, 1241.
1H NMR spectrum (CDCl3), δ, ppm: 0.85 t (3H, CH3,
J = 6.5 Hz), 1.20 t (3H, CH3, J = 7.1 Hz), 1.90 s and
2.00 s (OAc), 2.25 t (2H, CH2, J = 7.5 Hz), 2.50 q (2H,
CH2S, J = 7.1 Hz), 2.70 m (1H), 3.40 m (1H), 3.60 s
(3H, OCH3), 3.70– 4.25 m (3H), 4.20 br.s and 4.30 br.s
(0.5H each, 11-H), 4.40 br.s and 4.50 br.s (0.5H each,
OCHO), 5.00 m (1H, 15-H), 5.15 m (1H, 9-H), 5.40 m
1
1714, 1680, 1373, 1244, 1027. H NMR spectrum
(CDCl3), δ, ppm: 0.85 t (3H, CH3, J = 6.4 Hz), 1.20 t
(3H, CH3, J = 6.4 Hz), 1.96 s and 1.98 s (3H, OAc),
3.60 s (3H, OCH3), 4.40 m and 4.55 m (0.5H each,
2″-H), 5.0 m (1H, 9-H), 5.35 br.s (2H, CH=CH).
13C NMR spectrum (CDCl3), δC, ppm: 13.91 (CH3),
15.03 (CH3), 31.37 and 31.44 (C18), 33.51 (C2), 51.47
(OCH3), 94.64, 97.64, 100.18 (C2″), 170.34, 170.79,
170.88 (MeCO), 173.96 (CO2Me), 208.75, 209.44,
209.76, 210.09 (C15).
Methyl (±)-(5Z,9α,11α)-9-acetoxy-13-ethylsulfa-
nyl-15-hydroxy-11-(tetrahydro-2H-pyran-2-yloxy)-
prost-5-en-1-oate (21). Sodium tetrahydridoborate,
0.2 g (5.2 mmol), was added in portions under stirring
over a period of 1 h to a solution of 1.5 g (2.7 mmol)
of ketone 20 in 20 mL of methanol. When the reaction
13
(2H, CH=CH). C NMR spectrum (CDCl3), δC, ppm:
13.97 (CH3), 14.87 (CH3), 19.73 and 20.17 (C4″), 21.13
and 21.31 (CH3), 22.48 (C19), 24.78 (C3, C17), 25.46
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 51 No. 1 2015

VOSTRIKOV et al.
8
(C5″), 26.06 (C7), 26.58 (C4), 31.23 and 31.31 (C3″),
31.74 and 31.80 (C18), 33.47 (C2), 34.82 (C16), 37.22
(C14), 39.21, 40.03 and 40.35 (C10), 42.60 and 42.97
(C13), 44.41 and 45.01 (C8), 51.30 (OCH3), 51.40
(C12), 62.54 and 63.35 (C6″), 71.90 and 72.22 (C15),
75.36 and 75.75 (C9), 75.75 and 81.01 (C11), 96.86 and
100.14 (C2″), 128.41 and 129.67 (CH=CH), 170.53,
170.58, 170.79 and 170.93 (MeCO), 173.89 (C1).
product was extracted into ethyl acetate (3×50 mL).
The combined extracts were washed with an aqueous
solution of sodium hydrogen carbonate and with water,
dried over MgSO4, and evaporated under reduced
pressure. The residue was purified by silica gel
chromatography. Yield 0.8 g (86%), Rf 0.3 (petroleum
1
ether–ethyl acetate, 1:1). H NMR spectrum (CDCl3),
δ, ppm: 0.87 t (3H, CH3, J = 6.5 Hz); 2.04 s, 2.05 s,
2.06 s, 2.10 s, and 2.11 s (6H, OAc); 2.13 t (2H, 2-H,
J = 7.3 Hz), 3.65 s (3H, OCH3), 4.30 m (1H), 4.70 m
(0.5H), 4.94 m (0.4H), 5.00–5.20 m (2H), 5.30–5.50 m
(2H, CH=CH).
Methyl (±)-(5Z,9α,11α)-9,15-diacetoxy-13-eth-
anesulfonyl-11-(tetrahydro-2H-pyran-2-yloxy)-
prost-5-en-1-oate (23). A solution of 0.125 g of
(NH4)6Mo7O24·H2O in 40 mL of methanol was cooled
to 0°C, 3 mL of 30% hydrogen peroxide was added,
and the mixture was stirred for 1 h. A solution of 1.4 g
(2.34 mmol) of compound 22 in 10 mL of methanol
was then added, the mixture was stirred for 3 h at 0°C,
2.8 g of Na2SO3 was added, and the mixture was
allowed to warm up to room temperature and stirred
for 2 h more. The mixture was diluted with 200 mL of
methylene chloride and filtered through a Schott filter,
the precipitate was washed on a filter with 30 mL of
methylene chloride, the filtrate was evaporated under
reduced pressure, and the residue was purified by silica
gel chromatography. Yield 1.08 g (73%), colorless oily
substance, Rf 0.6 (petroleum ether–ethyl acetate, 1:1).
IR spectrum, ν, cm–1: 2942, 2862, 1736, 1455, 1436,
Methyl (±)-(5Z,9α)-9,15-diacetoxy-11-oxo-13-
(ethanesulfonyl)prost-5-en-1-oate (25). Pyri-
dinium chlorochromate, 6.14 g (28.5 mmol), was
added under stirring to a solution of 0.8 g (1.47 mmol)
of alcohol 24 in 120 mL of anhydrous methylene
chloride. When the reaction was complete (6 h, TLC),
the mixture was filtered through 50 cm3 of silica gel,
the filtrate was evaporated under reduced pressure, and
the residue was purified by silica gel chromatography.
Yield 0.69 g (86%), colorless oily material, Rf 0.3 (pe-
1
troleum ether–ethyl acetate, 7:3). H NMR spectrum
(CDCl3), δ, ppm: 0.85 t (3H, CH3, J = 7.1 Hz),
1.20–1.30 m (8H), 1.38 t (3H, CH3, J = 7.5 Hz),
1.50–1.60 m (4H), 1.96 s, 2.08 s, 2.09 s (OAc), 2.30 t
(2H, CH2, J = 6.5 Hz), 2.90–3.15 m (2H, SO2CH2),
3.65 s (3H, OCH3), 3.80 br.s (1H), 4.90 m (1H, 15-H),
1
1373, 1302, 1241, 1034, 730. H NMR spectrum
(CDCl3), δ, ppm: 0.85 t (3H, CH3, J = 6.6 Hz), 1.30 t
and 1.34 t (3H, CH3, J = 7.4 Hz), 2.04 s and 2.05 s
(OAc), 2.07 s (OAc), 2.30 t (2H, CH2, J = 7.1 Hz),
3.00 m (2H, SO2CH2), 3.65 s (3H, OCH3), 3.80 m (1H,
13-H), 4.40–4.70 m (2H, 2″-H, 11-H), 5.00–5.10 m
(2H, 9-H, 15-H), 5.35 m (2H, CH=CH). 13C NMR
spectrum (CDCl3), δC, ppm: 6.19 and 6.36 (CH3),
13.90 (CH3), 19.97 and 20.59 (C4″), 22.37 (C19), 24.68
(C3, C14, C17), 25.30 and 25.47 (C5″), 25.32 (C7), 26.55
(C5), 31.21 and 31.34 (C3″), 31.55 and 31.65 (C18),
33.80 (C2), 34.79 and 34.91 (C16), 36.80 and 39.47
(C10), 43.33 and 44.11 (C8), 46.86 (CH2SO2), 48.48
and 48.91 (C13), 51.38 (OCH3), 55.37 and 55.68 (C12),
62.96 and 63.94 (C6″), 71.25 and 71.45 (C15), 74.22
and 75.05 (C9), 76.25 and 80.36 (C11), 97.77 and
100.57 (C2″), 127.69, 127.81, 127.87, 130.03, 130.08,
130.20 (CH=CH), 170.26, 170.41, 170.52, 170.72
(MeCO), 173.88 (C1).
13
5.10 br.s (1H, 9-H), 5.40 m (2H, CH=CH). C NMR
spectrum (CDCl3), δC, ppm: 6.24 and 6.59 (CH3),
13.90 and 13.98 (CH3), 20.97, 21.01, 21.13, 21.20,
21.31 (MeCO), 22.47 (C19), 24.71, 24.76 and 24.81
(C3, C17), 26.59 and 26.64 (C7), 26.81 and 26.83 (C4),
31.57 and 31.62 (C18), 32.74 and 33.13 (C14), 33.44
and 33.48 (C2), 34.74 and 34.85 (C16), 37.75 and
43.31 (C10), 43.29 and 45.38 (C8), 46.39 and 46.52
(CH2SO2), 49.15 and 49.37 (C13), 51.50 (OCH3),
56.30 (C12), 70.31, 70.54, 71.35 and 71.42 (C15), 76.17
and 77.96 (C9), 126.17 and 127.18 (C6), 130.69 and
131.42 (C5), 170.27, 170.52, 170.56, 170.86 and
171.46 (MeCO), 173.91 and 173.96 (C1), 212.76 (C11).
(±)-15-Deoxy-Δ12,14-prostaglandin J2 methyl
ester (5). 1,8-Diazabicyclo[5.4.0]undec-7-ene,
0.2 g (1.3 mmol), was added to a solution of 0.65 g
(1.19 mmol) of ketone 25 in 100 mL of benzene, and
the mixture was stirred for 2 h. The mixture was fil-
tered through 20 cm3 of silica gel, the sorbent was
washed with ethyl acetate (3×50 mL), the filtrate was
combined with the washings and evaporated under
reduced pressure, and the residue was subjected to
Methyl (±)-(5Z,9α,11α)-9,15-diacetoxy-11-hy-
droxy-13-(ethanesulfonyl)prost-5-en-1-oate (24).
A solution of 1.08 g (1.71 mmol) of THP ether 23 in
70 mL of 60% acetic acid was heated for 1 h at 60°C.
The mixture was evaporated under reduced pressure,
the residue was diluted with 150 mL of water, and the
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 51 No. 1 2015

SYNTHESIS OF (±)-15-DEOXY-Δ12,14-PROSTAGLANDIN J2
9
silica gel chromatography. Yield 0.126 g (32%),
yellowish waxy material, Rf 0.55 (petroleum ether–
ethyl acetate, 7:3). IR spectrum, ν, cm–1: 2954, 2928,
The spectral and analytical data were obtained
using the equipment of the Khimiya Shared Use
Center, Institute of Organic Chemistry, Ufa Research
Center, Russian Academy of Sciences.
1
2856, 1738, 1695, 1634. H NMR spectrum (CDCl3),
δ, ppm: 0.89 t (3H, CH3, J = 7.0 Hz), 1.25–1.33 m
(4H, 18-H, 19-H), 1.45 quint (2H, 17-H, J = 7.2 Hz),
1.65 quint (2H, 3-H, J = 7.5 Hz), 2.20 q (2H, 3-H,
J = 7.3 Hz), 2.23 q (2H, 16-H, J = 7.3 Hz), 2.28 t (2H,
2-H, J = 7.5 Hz), 2.60 d.t (1H, 7-H), 3.58 m (1H,
8-H), 3.65 s (3H, OCH3), 5.33–5.39 m (1H, 6-H),
5.43–5.48 m (1H, 5-H), 6.25 d.t (1H, 15-H, J = 6.9,
14.9 Hz), 6.32 d.d (1H, 14-H, J = 11.4, 15.0 Hz),
6.36 d.d (1H, 10-H, J = 1.8, 6.1 Hz), 7.50 d (1H, 13-H,
J = 11.3 Hz), 7.47 d.d (1H, 9-H, J = 1.9, 6.0 Hz).
13C NMR spectrum (CDCl3), δC, ppm: 14.05, 22.51,
24.72, 26.69, 28.50, 30.76, 31.45, 33.43, 33.50, 43.51,
51.56, 125.67, 125.99, 131.50, 131.72, 135.06 (C12),
135.38, 146.96, 160.69, 173.94, 197.43. Mass spec-
trum, m/z (Irel, %): 330.3 (90) [M + H]+, 299 (10)
[M – OCH3]+, 259 (100) [M – C5H11]+. Calculated:
M 330.46.
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1.80 m (4H), 2.01 s and 2.05 s (3H, OAc), 2.25 m (2H),
2.50–2.70 m (2H), 3.45 m (1H), 3.65 s (3H, OCH3),
4.95 m (1H, 15-H), 5.30–5.50 m (2H, CH=CH),
6.35 d.d (1H, 10-H, J = 1.7, 6.0 Hz), 6.45 t (1H, 13-H,
J = 7.6 Hz), 7.50 d.d (1H, 9-H, J = 1.8, 6.0 Hz).
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RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 51 No. 1 2015