Prodigiosenes conjugated to tamoxifen and estradiol

Article abstract of DOI:10.1039/c7ob00943g

We report the synthesis of the first click-appended prodigiosene conjugates. Four prodigiosene conjugates of estradiol functionalised at the 7α-position were prepared, as were three prodigiosene conjugates of tamoxifen. The coupling between a prodigiosene and an 11-hydroxy estradiol derivative via an ether linkage was investigated, as was the 11- and 7-functionalisation of the estradiol core. The robustness of estradiol protecting groups was severely challenged by reactions typically used to equip such frameworks for 11- and 7-functionalisation. Specifically, and important to synthesis involving estradiol, TBS, TMS and THP are not useful protecting groups for the functionalisation of this core. When the chemical features of the therapeutic agent limit the choice of protecting group (in this case, prodigiosenes bearing aryl, NH, alkenyl and ester groups), click chemistry becomes an attractive synthetic strategy. The anti-cancer activity of the seven click prodigiosene conjugates was evaluated.

Full text of DOI:10.1039/c7ob00943g

Organic &
Biomolecular Chemistry
View Article Online
View Journal
PAPER
Prodigiosenes conjugated to tamoxifen and
estradiol†
Cite this: DOI: 10.1039/c7ob00943g
Estelle Marchal, Carlotta Figliola and Alison Thompson
*
We report the synthesis of the first click-appended prodigiosene conjugates. Four prodigiosene conju-
gates of estradiol functionalised at the 7α-position were prepared, as were three prodigiosene conjugates
of tamoxifen. The coupling between a prodigiosene and an 11-hydroxy estradiol derivative via an ether
linkage was investigated, as was the 11- and 7-functionalisation of the estradiol core. The robustness of
estradiol protecting groups was severely challenged by reactions typically used to equip such frameworks
for 11- and 7-functionalisation. Specifically, and important to synthesis involving estradiol, TBS, TMS and
THP are not useful protecting groups for the functionalisation of this core. When the chemical features of
the therapeutic agent limit the choice of protecting group (in this case, prodigiosenes bearing aryl, NH,
alkenyl and ester groups), click chemistry becomes an attractive synthetic strategy. The anti-cancer
activity of the seven click prodigiosene conjugates was evaluated.
Received 17th April 2017,
Accepted 9th June 2017
DOI: 10.1039/c7ob00943g
rsc.li/obc
Introduction
The conjugation of potent drugs to bioactive molecules (e.g.
1
–3
4
5–7
8
proteins,
lipids, antibodies
and biological polymers )
represents an effective and proven strategy for the treatment of
9
–11
cancer.
Conjugation allows specific tissues to be targeted
Fig. 1 Structure of prodigiosin and some prodigiosene analogs.
1
2
to result in reduced toxicity towards healthy cells. We herein
report conjugation of prodigiosenes to moieties that target
estrogen receptors. En route to synthesising these conjugates,
we discovered the surprising frailty of estradiol protecting natural product, have been shown to maintain the anticancer
groups. We thus used click chemistry to ensure robust connec- activity of the parent compound, as well as result in a reduced
3
2–41
tivity between the prodigiosene and the estradiol. The first toxicity profile.
click-appended prodigiosene conjugates are reported herein,
as are some tamoxifen–prodigiosene conjugates, alongside jugated to estrone, estradiol and 4-hydroxytamoxifen.
We previously reported prodigiosenes 1a–c (Fig. 2, top) con-
3
3,36
methodology that will be of use in the conjugation of either These prodigiosene conjugates were designed to be delivered
prodigiosenes or estradiols to other complex moieties.
to cancerous tissues that express estrogen receptors (ERs),
Prodigiosin is a tripyrrolic, red pigmented natural product thereby increasing the selectivity of these drugs towards ER-
1
2,42–45
produced by certain strains of Serratia and Streptomyces bac- positive breast cancer cells.
As a proof of principle,
Prodigiosin exhibits a multitude of biological these first conjugates were linked through the readily accessi-
1
3,14
teria (Fig. 1).
responses including immunosuppressive, antimicrobial
1
5
16–19
ble functionalities of the targeting moieties, even though
through several modes of those groups play a fundamental role in binding the ER pocket
Nevertheless, the conjugates exhibited growth
However, inhibition against breast cancer cells and some selectivity for
clinical applications have been limited due to poor selectivity. ER-positive breast cancer cell lines.
2
0,21
and anti-cancer properties
+
−
22–25
46,47
action, e.g. H /Cl exchange,
Cu-mediated DNA clea- (Fig. 2, top).
2
6,27
28–30
vage
and signal-transduction interference.
3
3,36
3
1
Derivatives of prodigiosin, named prodigiosenes, featuring
Herein, we report our investigations towards the synthesis
various modifications on the pyrrolyldipyrrin core of the of prodigiosenes conjugated to estradiol derivatives at the 11-
and 7-positions (Fig. 2, bottom). Linkage at these positions
would allow the free hydroxyl moieties at the 3- and
Department of Chemistry, Dalhousie University, PO BOX 15000, Halifax, NS, B3H
17β-positions of estradiol to bind ERs. Indeed, chemical sub-
4R2, Canada. E-mail: Alison.Thompson@dal.ca
stitution at the 11β- and 7α-positions of estrogens, although
more synthetically challenging than the 3- and 17β-positions,
†
Electronic supplementary information (ESI) available: Cancer cell line growth
inhibition data and NMR spectra (PDF). See DOI: 10.1039/c7ob00943g
This journal is © The Royal Society of Chemistry 2017
Org. Biomol. Chem.

View Article Online
Paper
Organic & Biomolecular Chemistry
Scheme 1 Synthesis of prodigiosene 5.
4
Reduction of the ester (4), using LiAlH , provided 5
Fig. 2 Conjugation strategy for prodigiosene–estradiol and tamoxifen (Scheme 1).
conjugates.
The synthesis of the requisite estradiol, functionalised with
a hydroxyl substituent at the 11α-position, began with the oxi-
dation of estrone to give 6, alongside 10% recovery of the start-
5
1,52
has given drugs with high binding affinities and potent estro-
genic or anti-estrogenic activities.
approach, 4-hydroxytamoxifen will be conjugated through the
amino side chain, thereby situating the free phenolic group
ing material within an inseparable mixture (Scheme 2).
Reduction of 6 gave the alcohol 7, which was protected with
4
6–49
Adhering to this
5
3
TBS to give 8. This protecting group was chosen to be stable
5
0
to reaction conditions suitable for the formation of esters
4
6,47
3
6
suitable for binding to ERs.
involving prodigiosenes:
choices for suitable protecting
groups are severely limited by the presence of the various func-
tionality embedded within the prodigiosene skeleton.
Hydroboration–oxidation of 8 gave the desired 11α-hydroxylated
estradiol derivative 9 (Scheme 2).
Results and discussion
Synthesis
The formation of the ether linkage was first attempted
using prodigiosene 5 and estrone and 4-hydroxytamoxifen.
3
6
Cognisant that ethers are less reactive than esters, we tar-
geted the synthesis of estradiol–prodigiosene conjugates
joined via an ether-linkage: a prodigiosene featuring a
pendant alcohol on the C-ring would be conjugated with an
estradiol substituted with a hydroxyl group at 11α-position
54
Using Mitsunobu conditions, estrone was coupled with 5 to
give 11a in reasonable yield (Scheme 3). However, the use of
these conditions gave rise to neither 11b (upon reaction with
4-hydroxytamoxiphen) nor 11c (upon reaction with 9). The
primary alcohol of prodigiosene 5 was thus activated to give
the tosylate 10, which was then reacted with estrone and
(
Fig. 3).
In order to synthesise a prodigiosene bearing a pendant
hydroxy group, the direct reduction of 2 was attempted.
However, the use of LiAlH gave a complex mixture of prodigio-
4
-hydroxytamoxifen under Williamson ether conditions.
However, conjugate 11a was obtained in only 17% yield, while
1b could not be adequately purified despite chromatography
over both silica and alumina. Use of the TBS-protected
1α-functionalised alcohol 9 was also unfruitful despite the
4
1
sene derivatives, and the use of BH ·THF afforded the reduced
3
product in only very poor yields. Therefore, prodigiosene 2 was
first protected as its Zn(II) dimer (3 in Scheme 1), whereupon
1
reduction of the ketone, using BH ·THF, was followed by an
3
acidic work-up that also effected decomplexation. It is signifi-
cant, particularly for those interested in the functional group
manipulation of dipyrrins, that reduction of this conjugated
carbonyl group is feasible following N–N protection with Zn(II).
Fig. 3 Moieties required for the synthesis of ether-linked estradiol–
prodigiosene conjugates.
Scheme 2 Synthesis of estradiol derivative 9.
Org. Biomol. Chem.
This journal is © The Royal Society of Chemistry 2017

View Article Online
Organic & Biomolecular Chemistry
Paper
Consequently, we protected the hydroxyl groups at the 3-
and 17β-positions as benzyl ethers, and planned to exchange
with TMS groups later in the sequence. We thus focused on
the 2-methoxyethoxymethyl ether (MEM) protecting group as it
5
6
is stable to hydrogenolysis and it has been removed, using
5
7,58
2
Ph BBr, in the presence of a TMS group on a beta-lactam.
We evaluated the protecting group orthogonality using readily
available 20 (Scheme 5, middle). Benzyl protection of 7 gave
the protected estradiol 16, along with ∼10% of the saturated
analogue that is carried from incomplete oxidation of estrone
(
1
Scheme 2). Subsequent hydroboration–oxidation gave the
Scheme 3 Attempts to synthesise ether-linked prodigiosene conju-
gates 11a–c.
1α-hydroxy derivative 17, and enabled separation of the satu-
5
3
rated analogue. MEM protection, followed by hydrogenolysis
and installation of TMS at the 3- and 17β-positions yielded
estradiol 20. Although removal of MEM in the presence of a
TMS protecting group was previously reported,
deprotection of estradiol 20 using Ph BBr resulted only in the
decomposition of our material. Yet again, a successful protec-
tion/deprotection strategy en route to estradiol–prodigiosene
conjugates defied the supporting evidence gained with model
systems.
We turned our attention to the 7α-position of the estradiol
backbone, given the challenging issues with the synthesis of
the required 11-substituted TMS and TBS derivatives.
Conjugation at the 7α-position has been shown to provide
fact that, upon treatment with NaH in DMF, 9 was quantitat-
ively recovered. Under the Williamson ether synthesis con-
ditions in the presence of tosylate 10, conjugate 11c was
formed but could not be extracted from DMF. Furthermore,
the use of high temperatures, in order to remove DMF, led to
decomposition. The reaction was repeated in THF, but the
desired product did not form. It is significant that such robust
reactions to form ethers fail with these bulky alcohols.
5
7,58
attempted
2
Considering the challenges encountered in forming ether
linkages (Scheme 3), we focused on the introduction of a
linker at the 11α-position of estradiol (Scheme 4) with the plan
to subsequently couple with prodigiosenes via either amide or
ester linkages that had previous shown to be forthcoming.
4
8
structures with high binding affinity to ERs, and potential
antagonist activity. Cognisant that the TMS protecting group
is stable to our planned esterification involving prodigio-
5
9
5
5
However, Williamson synthesis using linker 12, whose azide
could lead to an amine or hydroxyl group later in the
sequence, did not occur at the desired 11α-position (13) but
instead at the phenolic position, i.e. TBS-deprotection at the
phenolic position occurred. The TBS-protected alcohol 9 and
tosylate 10 thus seemed unable to tolerate clean reactivity at
the 11α-hydroxy position (Schemes 3 and 4).
3
6
senes, we focused on the preparation of 23a (Scheme 5,
5
9
bottom). The free hydroxyl groups of estradiol 21 were TMS-
protected to give 22a. However, debenzylation of 22a using Pd/
C at 1 atmosphere of hydrogen in ethanol occurred with the
removal of the TMS groups, and we attributed this phenom-
enon to the ready migration of silyl groups in protic
6
0–62
solvents.
Furthermore, the use of THF at 3 bar of hydrogen
Clearly, TBS is not a suitable protecting group for estradiol
derivatives of this type. In contrast, the TMS group survives the
conjugation of prodigiosenes with estradiols functionalised in
for 24 h afforded only a small amount of the desired alcohol.
After repeating these conditions three times using the same
material, 23a was isolated in moderate purity and just 17%
yield. As such, this route to TMS-protected functionalised
estradiols was also jettisoned. The THP-protected 22b was thus
targeted (Scheme 3). However, when attempting the hydro-
genolysis of 22b, unexpected migration of the THP group at
the phenolic position to the deprotected primary alcohol was
observed, with undesired 24 isolated as the major product.
Again, the fickleness of estradiol protecting groups is
surprising.
As attempts to synthesise TBS-, TMS- and THP-protected
estradiols were unyielding en route to 11- and 7-functionalised
derivatives, we turned our focus towards estradiols suited to
Cu(I)-catalyzed click chemistry with the goal of preparing the
first click-appended conjugates of prodigiosenes. Using this
approach, we anticipated being able to use protecting groups
not based on silicon, as we would no longer be bound by the
need to use esterification or etherification as a means of
joining the requisite halves of each conjugate. The methoxy-
methyl acetal (MOM) protecting group thus became available
33,35,36
other positions,
and has been demonstrated to be compa-
tible with the coupling conditions required to form such esters,
in contrast to the many protecting groups we evaluated.
Furthermore, TMS can be removed without hydrolysis of the
ester bond. As such, we targeted estradiol derivative 15
(
Scheme 5, top and middle) protected with TMS groups at 3-
51–53
and 17β-positions. Alcohol 7
was protected with TMS to
afford 14. However, the TMS groups in 7 did not survive the
hydroboration conditions (Scheme 5, top). Evidently, the robust-
ness of estradiol protecting groups is far from established.
Scheme 4 Attempt to synthesise estradiol derivative 13.
This journal is © The Royal Society of Chemistry 2017
Org. Biomol. Chem.

View Article Online
Paper
Organic & Biomolecular Chemistry
Scheme 5 Synthesis towards TMS-protected functionalised estradiols.
to us for this work. Our conjugates were designed to enable
the bioevaluation of the effect of linker chain lengths between (top). Coupling of pyrrole 32 with the linker 33 yielded 34,
the estradiol (25) and the prodigiosene moiety (26 and 27, which was subsequently condensed with pyrrolinone 35 to
Scheme 7). Furthermore, in order to appreciate the influence give the dipyrrinone 36. The activated bromo (37a) and triflate
Prodigiosene 26 was synthesised as shown in Scheme 7
38
63
6
4
a
of the pK of the prodigiosene moiety upon the biological pro- (37b) dipyrrins were obtained in 64% and 89% yield, respect-
3
8
perties of the final conjugates, prodigiosenes were designed ively. Both were subsequently subjected to Suzuki–Miyaura
to feature an azido group linked via an ester (26, Scheme 7, coupling conditions and (1-(tert-butoxycarbonyl)-1H-pyrrol-2-
top) or an alkyl group (27, Scheme 7, bottom) on the β-position yl)boronic acid to generate the key prodigiosene 26, the first of
of the C-ring. Prodigiosenes bearing these two functionalities its kind, bearing an ester-linked azide. Preparation of the pro-
have been shown to exhibit quite different properties in terms digiosene 27, bearing an alkyl-linked azide, commenced with
3
8
59
65
of acidity. Estradiol 28 was thus substituted with linkers the reduction of the methyl ester of pyrrole 38 to provide the
2
6
2
9a–b to give 30a–b. Deprotection of the MOM ethers, fol- alcohol 39 (Scheme 5, bottom). Subsequent tosylation, fol-
lowed by reduction of the ketone, afforded the desired estra- lowed by treatment with NaN , gave 41. Decarboxylation and
3
diol coupling partners 25a–b (Scheme 6).
formylation provided 42. Mukaiyama-aldol type condensation
4
1
between 42 and 35 gave the dipyrrinone 43, which was bro-
minated in preparation for Suzuki–Miyaura coupling to
provide prodigiosene 27.
6
6
The Cu(I)-catalyzed azide–alkyne cycloaddition (CuACC)
was then attempted using ester-linked azido prodigiosene 26
and the estradiol derivative 25b as coupling partners.
6
7,68
Although several sets of conditions were used,
decompo-
sition of the prodigiosene moiety was observed during the
reaction, presumably due to the complexation between the
dipyrrinato and pyrrolic nitrogen atoms and the copper
Scheme 6 Synthesis of protected estradiols bearing alkyne at
2
7
7
α-position.
species. The necessity to protect chelating ligands to enable
Org. Biomol. Chem.
This journal is © The Royal Society of Chemistry 2017

View Article Online
Organic & Biomolecular Chemistry
Paper
functionalised dipyrrins and their complexes such as those
7
0–75
used as probes or in optical devices.
Preparation of tamoxifen conjugates
With four prodigiosene–estradiol conjugates in hand, we
expanded the series through synthesis of three prodigiosenes
conjugated to 4-hydroxytamoxifen. (Z)-4-Hydroxytamoxifen
metabolite accounts for the anti-cancer activity of tamoxifen
through its high binding affinity to ERs and antagonist activity.
The E isomer is, instead, weakly estrogenic with a low binding
7
6
affinity for the receptor. However, the fact that the E/Z mixture
7
7
of 4-hydroxytamoxifen analogue 49 exhibits potencies similar
to tamoxifen itself, as regards to ER affinity assays and ER
2
7
antagonist activity, prompted us to use that substrate to build
-hydroxytamoxifen conjugated to prodigiosenes 1a–c. The
4
tamoxifen derivative 49 was thus selectively protected with TBS
at the phenolic position to give 50 (Scheme 8). Coupling of 50
33
with prodigiosenes 1a–c (Fig. 2), followed by deprotection,
successfully afforded conjugates 51a–c (Scheme 9).
Anti-cancer activity
The seven conjugates 46a–b, 48a–b and 51a–c were evaluated by
Scheme 7 Synthesis of ester- and alkyl linked prodigiosenes bearing
azide.
the National Cancer Institute (NCI) across sixty cell lines (NCI-60)
78
representing nine types of cancer, and the activities were found
to be moderate. Growth inhibition results at 10 μM of prodigio-
sene–hydroxytamoxifen conjugates 51a–c against six human
breast cancer cell lines, including MCF7 and T-47D (ER-positive
cell lines) and MDA-MB-231/ATCC, HS 578 T, BT-549, MDA-MB
6
9
CuACC has been previously noted. Consequently, we pro-
tected prodigiosene 26 as a zinc complex (45, Scheme 8).
Gratifyingly, the use of CuI, tris(benzyltriazolylmethyl)amine
468 (ER-negative cell lines) are shown in the ESI.† Focusing on
our goal to target breast cancer with conjugates that are designed
to target ER receptors, the results are compared to the previously
(
TBTA) and diisopropylamine in THF successfully promoted
the CuACC reaction between the prodigiosene zinc complex 45
and estradiols 25a–b, which, after zinc decomplexation using
aqueous HCl, afforded the prodigiosene–estradiol conjugates
33
synthesised conjugates, where the prodigiosene moiety is
attached via the phenolic position of 4-hydroxytamoxifen that is
considered essential for binding. The chain length of the linker
of conjugates 51a–c proved not to influence the extent of growth
inhibition, nor did the presence of the conjugated carbonyl
moiety. Unexpectedly, conjugates 51a–c, exhibiting the free phe-
nolic group of tamoxifen are less efficient at inhibiting breast
cancer cell growth than those conjugates wherein the phenolic
group is engaged in the conjugation with the prodigiosene unit.
In contrast, high activity is observed for conjugate 51a against the
ER-negative MDA-MB-231/ATCC cell line.
4
6a–b. Similarly, coupling estradiols 25a–b and the alkyl-
linked azido prodigiosene zinc complex 47 returned the
desired prodigiosene–estradiol conjugates 48a–b (Scheme 8).
In general terms, it is significant that the dipyrrinato moiety
was shown to undergo CuACC only when the N–N feature was
protected. This discovery will be of use in the synthesis of
The anticancer activity of 1,2,3-triazole prodigiosene–estra-
diol conjugates 46a–b and 48a–b are also provided in the ESI.†
The alkyl-containing 48a–b (higher pK ) displayed enhanced
a
growth inhibition compared to the ester-containing conjugates
Scheme 8 Synthesis of 1,2,3-triazole-linked prodigiosene–estradiol
conjugates.
Scheme 9 Synthesis of prodigiosene-4-hydroxytamoxifen conjugates.
This journal is © The Royal Society of Chemistry 2017
Org. Biomol. Chem.

View Article Online
Paper
Organic & Biomolecular Chemistry
4
6a–b (lower pK
a
), suggesting that the pK
a
of the prodigiosene formed in flame-dried glassware under a positive pressure of
skeleton plays a role on the anti-cancer activity as a function of nitrogen or argon. Air- and moisture-sensitive compounds
enhanced transmembrane anion exchange rates, in line with were introduced via syringe or cannula through a rubber
3
6
previous work. Akin to the conjugates to tamoxifen, the linker septum. Flash chromatography was performed using ultra-
length is not significant upon growth inhibition suggesting that pure silica (230–400 mm) or 150 mesh Brockmann III activated
for prodigiosene conjugates of this genre, alkyl linkers of any neutral or basic alumina oxide as indicated. An automated
length are equally valid. However, compound 48b also displayed system was employed for some chromatography, using pre-
unexpectedly high growth inhibition against the MDA-MB-231/ packed KP-Sil Silica SNAP cartridges. NMR spectra were
ATCC cell line. The unusual activity against MDA-MB-231/ATCC recorded using 500 MHz or 300 MHz spectrometer instru-
line for both 48b and 51a is intriguing, particularly in light of ments. Chemical shifts (δ) are reported in parts per million
the fact that this metastatic human mammary carcinoma cell (ppm) using the solvent signals as reference (CDCl 7.26 ppm
3
1
13
1
line has been shown to display higher TEA domain (TEAD) tran- for H, 77.16 ppm for C while; MeOD 3.31 ppm for H,
scriptional activity than non-metastatic mammary carcinoma 49.00 ppm for C; DMSO 2.50 ppm for H, 39.51 ppm for C).
cell lines such as MCF7. TEAD plays a critical role in the func- Coupling constants, J, are reported in hertz. Mass spectra were
1
3
1
13
79
tion of YAP (yes-associated protein), a protein that aids in cell obtained using TOF and LCQ Duo ion trap instruments operat-
+
−
33
39
51–53
proliferation and the suppression of apoptosis, and so the YAP/ ing in ESI or ESI mode. Compounds 1a–c, 2, 6–9,
5
5
53
53
59
63
62
38
63
64
65
77
TEAD complex has been suggested as a useful pharmacological 12, 16, 17, 21, 28, 29a, 32, 33, 35, 38, 49
8
0–84
target for the treatment of proliferative diseases.
Of rele- were prepared following literature procedures.
vance to the results described herein, protoporphyrin IX,
hematoporphyrin and verteporfin have been shown to inhibit
the YAP/TEAD interaction, and thus suppress the oncogenic
Zinc complex of (Z)-ethyl 3-(2-((4-methoxy-1H,1′H-[2,2′-
bipyrrol]-5-yl)methylene)-3,5-dimethyl-2H-pyrrol-4-yl)-3-
oxopropanoate (3)
85
effects of YAP. Given the structural similarity of these three
porphyrins to the tripyrrolic nature of the prodigiosenes reported To a solution of prodigiosene 2 (0.80 g, 1.88 mmol) in CHCl3
herein, the activity of 48b and 51a against MDA-MB-231/ATCC (200 mL) was added a solution of Zn(OAc) ·2H O (1.03 g,
2
2
warrants further investigation, including the potential for photo- 4.79 mmol) and NaOAc (0.42 g, 5.07 mmol) in MeOH (55 mL).
dynamic therapy effects, now that a reliable synthetic route is After stirring for 6 hours at room temperature, water (150 mL)
available for conjugates of this type.
was added and the crude mixture then extracted with CH
3 × 150 mL). The combined organic layers were washed with
brine (150 mL) and dried over Na SO . After evaporation of the
2 2
Cl
(
2
4
solvent under reduced pressure, the crude solid was purified
using flash chromatography on Al neutral Brockman III
Conclusions
2 3
O
In summary, the synthesis of estradiol–prodigiosene conju- (EtOAc/hexanes 30/70, 40/60, 50/50 then 60/40) to give the title
gates via an ether linkage, as a more stable alternative than compound as a green-red solid (0.61 g, 71%). R = 0.5 Al
, 500 MHz)
f
2 3
O
1
ester, has been attempted. The robustness of estradiol protect- (EtOAc/hexane 70/30). Mp = 73 °C. H NMR (CDCl
3
ing groups has been challenged by reactions typically used to 1.22 (t, J = 7.5 Hz, 3H), 1.65–1.67 (m, 8H), 2.16 (s, 6H), 2.31 (t,
equip such frameworks for 11- and 7-functionalisation. J = 7.0 Hz, 4H), 2.54 (s, 3H), 2.68–2.71 (m, 4H), 3.99 (s, 6H),
Specifically, TBS, TMS and THP are not useful protecting 4.05 (q, J = 7.5 Hz, 4H), 6.06 (s, 1H), 6.10–6.11 (m, 1H),
groups for the functionalisation of estradiol. When the chemi- 6.49–6.50 (m, 1H), 6.61–6.62 (m, 1H), 7.35 (s, 1H), 9.22 (s, 1H).
1
3
cal features of the therapeutic agent limit the choice of protect-
3
C NMR (CDCl , 125 MHz) 13.1, 14.4, 18.1, 23.8, 24.9, 34.4,
ing group (in our case, prodigiosenes bearing aryl, NH, alkenyl 42.3, 58.5, 60.3, 96.1, 110.7, 114.4, 117.9, 123.1, 126.5, 126.9,
and ester groups), click chemistry becomes an attractive syn- 131.9, 133.1, 138.7, 155.5, 155.8, 167.0, 173.8, 197.3. HRMS-ESI
+
thetic strategy. We herein report the first click-appended prodi- (m/z): [M + Na] calcd for C48
giosene conjugates: four prodigiosene conjugates of estradiol, 931.3320.
functionalised at the 7α-position, were prepared, as were three
56 6 8
H N NaO Zn: 931.3343; found
(
Z)-Ethyl 6-(2-((4-methoxy-1H,1′H-[2,2′-bipyrrol]-5-yl)
prodigiosene conjugates of tamoxifen. The critical features of
the targeting moieties were available for binding to ERs, and
the influence of such groups was assessed through evaluation
methylene)-3,5-dimethyl-2H-pyrrol-4-yl)hexanoate
hydrochloride (4)
of anti-cancer activity. Unexpected growth inhibition activity To a solution of prodigiosene 3 (0.17 g, 0.18 mmol) in an-
was observed against the MDA-MB-231/ATCC cell line, which hydrous THF (35 mL) was added BH ·THF (1 M, 0.75 mL,
3
evidently cannot be ascribed to targeting via the ER.
0.75 mmol), under inert atmosphere. After stirring for 3 hours
at room temperature, the reaction was quenched through
the addition of HCl (1 M, 35 mL) and extracted with CH
3 × 50 mL). The combined organic layers were washed with
brine (50 mL), dried over Na SO and concentrated under
2 2
Cl
(
Experimental procedures
2
4
All chemicals were purchased and used as received unless reduced pressure to give the title compound as a red solid
otherwise indicated. Moisture sensitive reactions were per- (0.17 g, quant.), which was used in the next step without
Org. Biomol. Chem.
This journal is © The Royal Society of Chemistry 2017

View Article Online
Organic & Biomolecular Chemistry
Paper
1
3
f 2 3 3
further purification. R = 0.40 Al O (EtOAc/hexane 50/50). 8.2 Hz, 2H), 7.76 (d, J = 8.2 Hz, 2H). C NMR (CDCl ,
1
H NMR (CDCl , 500 MHz) 1.24 (t, J = 7.5 Hz, 3H), 1.31–1.35 125 MHz) 9.7, 10.6, 21.7, 24.1, 25.3, 28.9, 28.9, 30.5, 58.5, 70.8,
3
(
(
m, 2H), 1.40–1.45 (m, 2H), 1.63 (quint., J = 7.5 Hz, 2H), 2.19 95.2, 109.9, 111.8, 113.4, 122.3, 122.7, 125.8, 128.0, 128.9,
s, 3H), 2.28 (t, J = 7.5 Hz, 2H), 2.37 (t, J = 7.5 Hz, 2H), 2.51 129.5, 129.9, 133.3, 136.6, 144.7, 158.5, 168.6. HRMS-ESI (m/z):
+
(s, 3H), 3.98 (s, 3H), 4.11 (q, J = 7.5 Hz, 2H), 6.06 (s, 1H), [M + H] calcd for C H N O S: 522.2421; found 522.2412.
2
9
36 3 4
6
.30–6.32 (m, 1H), 6.85–6.86 (m, 1H), 6.99 (s, 1H), 7.17–7.18
(
13S,14S)-3-((6-((Z)-2-((4-Methoxy-1H,1′H-[2,2′-bipyrrol]-5-yl)
(
m, 1H), 12.48 (bs, 1H), 12.51 (bs, 1H), 12.57 (bs, 1H).
1
3
methylene)-3,5-dimethyl-2H-pyrrol-4-yl)hexyl)oxy)-13-methyl-
7
1
C NMR (CDCl , 125 MHz) 10.1, 12.6, 14.4, 24.0, 29.0, 30.0,
3
,8,9,11,12,13,15,16-octahydro-6H-cyclopenta[a]phenanthren-
7(14H)-one (11a)
3
1
4.4, 58.7, 60.4, 92.7, 111.5, 113.1, 116.3, 119.7, 122.5, 124.4,
26.3, 126.6, 137.8, 146.7, 147.5, 165.3, 173.8. HRMS-ESI (m/z):
+
[M + H − HCl] calcd for C H N O : 410.2438; found To a solution of estrone (0.031 g, 0.11 mmol) in anhydrous
2
4
32 3 3
4
10.2431.
DMF (3 mL) was added NaH (5.0 g, 0.11 mmol) at 0 °C and
under inert atmosphere. The reaction mixture was stirred for
(
Z)-3-(2-((4-Methoxy-1H,1′H-[2,2′-bipyrrol]-5-yl)methylene)-3,5-
40 min at room temperature then cooled down to 0 °C and a
dimethyl-2H-pyrrol-4-yl)propan-1-ol hydrochloride (5)
solution of prodigiosene 10 (0.05 g, 0.095 mmol) in anhydrous
To a suspension of LiAlH (0.085 g, 2.24 mmol) in anhydrous DMF (1 mL) was added. The reaction was stirred overnight at
THF (10 mL) was added a solution of prodigiosene 4 (0.50 g, room temperature, then quenched with 1% HCl. The reaction
.12 mmol) in anhydrous THF (40 mL) under inert atmo- mixture was extracted with CH Cl (3 × 30 mL) and the com-
4
1
2
2
sphere. After stirring for 2 hours at room temperature, the bined organic layers washed with water (2 × 30 mL) and brine
reaction was quenched through the addition of a saturated (1 × 30 mL), then dried over Na SO and concentrated under
2
4
solution of Na
was extracted with CH
layers were washed with brine (50 mL), dried over Na SO and EtOAc/hexane, 40/60) to give the title compound as a red film
2
SO
4
(10 mL) and HCl 5% (50 mL). The mixture vacuum. The crude mixture was purified using flash chromato-
2
Cl (3 × 50 mL). The combined organic graphy (Al neutral type III, EtOAc/hexane, 40/60) then (SiO
2
2
O
3
2
,
2
4
1
concentrated under reduced pressure. The crude mixture was (17 mg, 17%). R
purified using flash chromatography on Al Brockman III (CDCl , 500 MHz) 0.90 (s, 3H), 1.35–1.39 (m, 3H), 1.44–1.52
neutral (EtOAc/hexane, 50/05 then 70/30) to give through the (m, 8H), 1.57–1.66 (m, 4H), 1.76 (quint., J = 6.5 Hz, 2H),
addition of as a red solid (0.26 g, 50%). R = 0.30 Al (EtOAc/ 1.92–2.04 (m, 3H), 2.10–2.15 (m, 1H), 2.22 (s, 3H), 2.38–2.41
, 500 MHz) 1.29–1.38 (m, 4H), (m, 3H), 2.48–2.51 (m, 1H), 2.54 (s, 3H), 2.87–2.88 (m, 2H),
.39–1.45 (m, 2H), 1.55 (quint., J = 6.5 Hz, 2H), 2.19 (s, 3H), 3.92 (t, J = 6.5 Hz, 2H), 4.00 (s, 3H), 6.08 (d, J = 1.5 Hz, 1H),
f 2 3
= 0.50 (Al O , EtOAc/hexane, 40/60). H NMR
2
O
3
3
f
2 3
O
1
hexane, 50/50). H NMR (CDCl
3
1
2
3
6
1
2
1
.36 (t, J = 6.5 Hz, 2H), 2.51 (s, 3H), 3.62 (t, J = 6.5 Hz, 2H), 6.33–6.34 (m, 1H), 6.63 (d, J = 2.5 Hz, 1H), 6.70 (dd, J = 8.5 and
.97 (s, 3H), 6.05 (s, 1H), 6.29–6.30 (m, 1H), 6.84–6.85 (m, 1H), 2.5 Hz, 1H), 6.88 (bs, 1H), 7.03 (s, 1H), 7.17–7.20 (m, 2H),
.99 (s, 1H), 7.16–7.18 (m, 1H), 12.45 (bs, 1H), 12.47 (bs, 1H), 12.51 (bs, 1H), 12.56 (bs, 1H), 12.62 (bs, 1H). C NMR (CDCl3,
2.51 (bs, 1H). C NMR (CDCl , 125 MHz) 10.1, 12.6, 24.1, 125 MHz) 10.2, 12.7, 14.0, 21.7, 24.1, 26.0, 26.1, 26.7, 29.2,
3
5.7, 29.3, 30.3, 32.8, 58.7, 62.9, 92.7, 111.5, 113.1, 116.2, 29.4, 29.8 (2C), 30.3, 31.7, 36.0, 38.5, 44.1, 48.1, 50.5, 58.7,
1
3
1
3
19.7, 122.5, 124.4, 126.3, 126.9, 137.9, 146.6, 147.6, 165.2. 67.8, 92.7, 111.5, 112.2, 113.2, 114.6, 116.2, 119.7, 122.5, 124.4,
+
HRMS-ESI (m/z): [M + H − HCl] calcd for C22
H
30
N
3
O
2
:
126.3, 126.4, 126.9, 132.0, 137.8, 137.9, 146.6, 147.7, 157.2,
+
3
68.233; found 368.2314.
165.2, 221.1. HRMS-ESI (m/z): [M + H] calcd for C40
20.3847; found 620.3847.
50 3 3
H N O :
6
(
Z)-6-(2-((4-Methoxy-1H,1′H-[2,2′-bipyrrol]-5-yl)methylene)-3,5-
dimethyl-2H-pyrrol-4-yl)hexyl 4-methylbenzenesulfonate (10)
(11R,13S,14S,17S)-3,17-Bis(trimethylsilyloxy)-11-((2-
methoxyethoxy)methoxy)-13-methyl-7,8,9,11,12,13,14,15,16,17-
decahydro-6H-cyclopenta[a]phenanthrene (14)
TsCl (0.62 g, 1.63 mmol) and (iPr) EtN (1.13 mL, 3.26 mmol)
were added to a solution of prodigiosene 5 (0.60 g, 0.82 mmol)
2
5
3
2 2
in anhydrous CH Cl (120 mL) at room temperature and under To a solution of 7 (400 mg, 1.48 mmol) in DMF (40 mL) was
inert atmosphere. The reaction mixture was stirred for 19 h, added imidazole (2.00 g, 29.6 mmol) followed by TMSCl
quenched through the addition of a saturated aqueous solu- (1.80 mL, 14.8 mmol). After stirring at room temperature for
tion of NH
The combined organic layers were washed with brine (50 mL), with diethyl ether (3 × 50 mL). The combined organic layers
dried over Na SO and concentrated under reduced pressure. were washed with water (2 × 50 mL) and brine (50 mL), then
The crude mixture was purified using flash chromatography dried (Na SO ). After evaporation of the solvent under reduced
on Al O Brockman III neutral, (EtOAc/hexane, 40/60, 50/50 pressure the crude material was purified using flash chromato-
4 2 2
Cl (80 mL) and extracted with CH Cl (3 × 50 mL). 16 h, water (150 mL) was added and the mixture was extracted
2
4
2
4
2
3
2
then 80/20) to give the title compound as a red solid (0.45 g, graphy (SiO , EtOAc/hexane 1/9) to give a colorless oil (604 mg,
1
1
5
5
7
2
6
3%). R
f
: 0.37 (Al
2
O
3
, EtOAc/hexane 50/50). H NMR (CDCl
3
,
98% that contained 10% of the saturated analogue). H NMR
00 MHz) 1.14–1.19 (m, 2H), 1.22–1.27 (m, 4H), 1.57 (t, J = (CDCl , 500 MHz): δ 0.12 (s, 9H), 0.27 (s, 9H), 0.78 (s, 3H),
3
.5 Hz, 2H), 1.71 (bs, 3H), 2.07 (s, 3H), 2.15 (t, J = 7.0 Hz, 2H), 1.29–1.45 (m, 3H), 1.53–1.60 (m, 1H), 1.77–1.84 (m, 1H),
.41 (s, 3H), 3.97 (s, 3H), 3.98 (t, J = 7.0 Hz, 2H), 6.07 (s, 1H), 1.92–2.09 (m, 4H), 2.15–2.19 (m, 1H), 2.75–2.89 (m, 2H), 3.73
.11 (s, 1H), 6.60 (s, 1H), 6.63 (s, 1H), 6.88 (s, 1H), 7.31 (d, J = (t, J = 5.1 Hz, 1H), 6.12–6.13 (m, 1H), 6.56 (d, J = 2.5 Hz, 1H),
This journal is © The Royal Society of Chemistry 2017
Org. Biomol. Chem.

View Article Online
Paper
Organic & Biomolecular Chemistry
13
+
6
.64 (dd, J = 8.7, 2.5 Hz, 1H), 7.49 (d, J = 8.7 Hz, 1H). C NMR 132.2, 139.6, 154.0. HRMS-ESI (m/z): [M + Na] calcd for
(
CDCl , 125 MHz): δ 0.4, 11.4, 24.2, 28.4, 30.1, 31.1, 39.1, 39.6, C H Na O , 399.2142; found, 399.2131.
3
22 32
1 5
4
1
4
1.8, 47.3, 81.9, 118.2, 118.3, 120.1, 125.1, 128.4, 135.2, 137.6,
+
(11R,13S,14S,17S)-3,17-Bis(trimethylsililoxy)-11-((2-
methoxyethoxy)methoxy)-13-methyl-7,8,9,11,12,13,14,15,16,17-
decahydro-6H-cyclopenta[a]phenanthrene (20)
53.9. HRMS-APCI (m/z): [M + H] calcd for C24
H
39
O
2
Si
2
,
15.2483; found, 415.32483.
To a solution of 19 (260 mg, 0.69 mmol) in THF (10 mL) was
(11R,13S,14S,17S)-3,17-Bis(benzyloxy)-11-((2-methoxyethoxy)
added Et N (0.58 mL, 3.46 mmol) followed by TMSCl (0.44 mL,
methoxy)-13-methyl-7,8,9,11,12,13,14,15,16,17-decahydro-6H-
cyclopenta[a]phenanthrene (18)
3
2
(
×
(
.76 mmol). After stirring at room temperature for 16 h, water
30 mL) was added and the mixture was extracted with EtOAc (3
40 mL). The combined organic layers were washed with brine
50 mL), then dried (Na SO ). After evaporation of the solvent
the title compound was obtained as a colorless oil (350 mg,
5
3
To a solution of 17 (370 mg, 0.79 mmol) in CH Cl (8.0 mL)
2
2
was added DIPEA (0.69 mL, 3.95 mmol) followed by MEMCl
0.23 mL, 1.97 mmol). After stirring at room temperature
2
4
(
for16 h, a saturated solution of NH Cl (30 mL) was added. The
4
1
9
0
2
7%). H NMR (CDCl , 300 MHz): δ 0.10 (s, 9H), 0.25 (s, 9H),
3
mixture was stirred for 15 min, and then extracted with EtOAc
.72 (s, 3H), 1.17–1.61 (m, 6H), 1.61–1.69 (m, 1H), 1.79–2.01 (m,
H), 2.29 (t, J = 10.0 Hz, 1H), 2.47 (dd, J = 12.0, 5.1 Hz, 1H), 2.74
(3 × 40 mL). The combined organic layers were washed with
brine (50 mL), then dried (Na SO ). After evaporation of the
2
4
(
t, J = 6.6 Hz, 2H), 3.41 (s, 3H), 3.58 (t, J = 4.7 Hz, 2H), 3.65 (t, J =
solvent under reduced pressure the crude was purified using
flash chromatography (SiO , EtOAc/hexane 2/8) to give the title
compound as a white solid (335 mg, 76%). Mp 70 °C. H NMR
8
4
2
1
2
9
.2 Hz, 1H), 3.74–3.82 (m, 2H), 4.14 (dt, J = 10.2, 5.1 Hz, 1H),
.91 (d, J = 7.0 Hz, 1H), 5.03 (d, J = 7.0 Hz, 1H), 6.57 (d, J =
2
1
.7 Hz, 1H), 6.61 (dd, J = 8.5, 2.5 Hz, 1H), 7.52 (d, J = 8.5 Hz,
(
(
CDCl , 500 MHz): δ 0.84 (s, 3H), 1.27–1.33 (m, 3H), 1.35–1.46
m, 2H), 1.57–1.69 (m, 2H), 1.83–1.87 (m, 1H), 2.04–2.11 (m,
3
13
3
H). C NMR (CDCl , 125 MHz): δ 0.3, 0.4, 12.2, 23.3, 27.1,
8.7, 31.0, 37.7, 43.6, 44.0, 47.9, 49.4, 59.1, 67.9, 71.9, 78.1, 81.2,
1H), 2.32 (t, J = 10.0 Hz, 1H), 2.64 (dd, J = 12.2, 5.2 Hz, 1H),
2.78 (t, J = 6.7 Hz, 2H), 3.40 (s, 3H), 3.52 (t, J = 8.2 Hz, 1H),
3.56–3.62 (m, 2H), 3.75–3.82 (m, 2H), 4.14–4.19 (m, 1H), 4.57
4.8, 117.0, 119.6, 126.7, 133.4, 139.4, 153.1. HRMS-ESI (m/z):
+
[M + Na] calcd for C28
1 5 2
H48Na O Si , 543.2932; found, 543.2907.
(s, 2H), 4.90 (d, J = 6.7 Hz, 1H), 5.03–5.04 (m, 3H), 6.73 (d, J =
(
((7R,13S,14S,17S)-7-(6-(Benzyloxy)hexyl)-17-((trimethylsilyl)
2
7
.5 H, 1H), 6.77 (dd, J = 8.7, 2.5 Hz, 1H), 7.27–7.40 (m, 8H),
.43 (d, J = 7.5 Hz, 2H), 7.63 (d, J = 9.0 Hz, 1H). C NMR
oxy)-13-methyl-7,8,9,11,12,13,14,15,16,17-decahydro-6H-
cyclopenta[a]phenanthren-3-yl)oxy)trimethylsilane (22a)
13
(
CDCl , 125 MHz): δ 12.7, 23.2, 27.0, 28.1, 28.9, 37.4, 44.0,
3
59
To a solution of 21 (480 mg, 1.04 mmol) in DMF (25 mL)
4
1
1
4.3, 47.8, 49.9, 59.2, 68.0, 70.0, 71.8, 71.9, 77.8, 87.7, 94.7,
12.0, 114.5, 127.0, 127.5, 127.6, 127.9, 128.4, 128.7, 133.0,
was added imidazole (2.94 g, 43.2 mmol), followed by TMSCl
2.74 mL, 21.6 mmol). After stirring at room temperature for
6 h, water (100 mL) was added and the mixture was extracted
with diethyl ether (3 × 40 mL). The combined organic layers
were washed with water (2 × 40 mL), then brine (50 mL). After
evaporation of the solvent under reduced pressure the crude
(
1
+
37.5, 139.2, 139.5, 157.0. HRMS-ESI (m/z): [M + Na] calcd for
C H Na O , 579.3081; found, 579.3073.
3
6
44
1 5
(
11R,13S,14S,17S)-11-((2-Methoxyethoxy)methoxy)-13-methyl-
,8,9,11,12,13,14,15,16,17-decahydro-6H-cyclopenta[a]
phenanthrene-3,17-diol (19)
To a degassed (bubbling with nitrogen for 3 min) solution of (415 mg, 66%). H NMR (CDCl , 500 MHz): δ 0.10 (s, 9H), 0.26
7
material was purified using flash chromatography (SiO
EtOAc/hexane 1/9) to give the title compound as a colorless oil
2
,
1
3
1
8 (450 mg, 0.81 mmol) in a mixture of THF/EtOH (15/20 mL) (s, 9H), 0.75 (s, 3H), 0.98–1.05 (m, 1H), 1.14–1.20 (m, 3H),
was added Pd/C 10% (50 mg) and 2 drops of triethylamine. 1.26–1.35 (m, 6H), 1.44–1.50 (m, 2H), 1.56–1.62 (m, 4H),
The mixture was then purged 3 times with 1 bar of hydrogen, 1.71–1.73 (m, 1H), 1.81–1.85 (m, 1H), 1.89–1.96 (m, 1H),
then stirred at 3 bar of hydrogen for 18 h. The reaction mixture 2.26–2.30 (m, 2H), 2.68 (d, J = 16.5 Hz, 1H), 2.84 (dd, J = 16.5,
was degassed using nitrogen, then filtered through a pad of 5.2 Hz, 1H), 3.44 (t, J = 6.2 Hz, 2H), 3.65 (t, J = 8.5 Hz, 1H), 4.49
Celite® washing with MeOH. After evaporation of the solvent (s, 2H), 6.54 (d, J = 2.5 Hz, 1H), 6.62 (dd, J = 8.5, 2.5 Hz, 1H),
1
3
3
under reduced pressure, the same procedure was repeated to 7.13 (d, J = 8.5 Hz, 1H), 7.25–7.34 (m, 5H). C NMR (CDCl ,
obtain the title compound as a colorless oil (260 mg, 85%). 125 MHz): δ 0.4, 0.5, 11.5, 22.9, 25.7, 26.4, 27.4, 28.3, 29.9,
1
H NMR (CDCl , 500 MHz): δ 0.73 (s, 3H), 1.21–1.26 (m, 3H), 30.0, 30.5, 31.0, 33.4, 34.7, 37.4, 38.4, 42.1, 43.6, 46.3, 70.6,
3
1
1
2
3
.35–1.42 (m, 2H), 1.46–1.53 (m, 1H), 1.63–1.67 (m, 1H), 73.0, 81.9, 117.2, 120.9, 126.8, 127.6, 127.7, 128.5, 132.8, 137.0,
+
.79–1.84 (m, 1H), 2.07–2.13 (m, 1H), 2.28 (t, J = 10.0 Hz, 1H), 138.8, 152.9. HRMS-ESI (m/z): [M
+
Na] calcd for
.51 (dd, J = 12.0, 5.0 Hz, 1H), 2.70–2.72 (m, 2H), 3.41 (s, 3H), C H Na O Si , 629.3817; found, 629.3798.
3
7
58
1
3
2
.57–3.64 (m, 2H), 3.73–3.77 (m, 2H), 3.79–3.83 (m, 1H), 4.12
6
7
-((7R,13S,14S,17S)-13-Methyl-3,17-bis((trimethylsilyl)oxy)-
,8,9,11,12,13,14,15,16,17-decahydro-6H-cyclopenta[a]
(dt, J = 10.0, 5.0 Hz, 1H), 4.87 (d, J = 7.0 Hz, 1H), 5.00 (d, J =
7
8
1
4
.0 Hz, 1H), 6.39 (s, 1H), 6.56 (d, J = 2.8 Hz, 1H), 6.59 (dd, J =
.5, 2.8 Hz, 1H), 7.49 (d, J = 8.5 Hz, 1H). C NMR (CDCl ,
3
1
3
phenanthren-7-yl)hexan-1-ol (23a)
25 MHz): δ 11.9, 23.1, 26.9, 28.6, 30.3, 37.8, 43.2, 43.9, 47.6, To a degassed (bubbled with nitrogen for 3 min) solution of
9.6, 59.1, 67.9, 71.9, 78.0, 81.3, 94.8, 112.5, 115.0, 126.9, estradiol 22a (425 mg, 0.7 mmol) in THF (25 mL) was added
Org. Biomol. Chem.
This journal is © The Royal Society of Chemistry 2017

View Article Online
Organic & Biomolecular Chemistry
Paper
Pd/C 10% (300 mg) and 2 drops of triethylamine. The mixture (15/10 mL) was added Pd/C 10% (300 mg) and 2 drops of
was purged 3 times with 1 bar of hydrogen, then stirred at 3 triethylamine. The mixture was then purged 3 times with 1 bar
bar of hydrogen for 24 h. The reaction mixture was degassed of hydrogen, then stirred at 2.8 bar of hydrogen for 18 h. The
using nitrogen, then filtered through a pad of Celite® washing reaction mixture was then degassed using nitrogen, then fil-
with CH Cl . This procedure was repeated 3 times. After evapo- tered through a pad of Celite® washing with CH Cl . After
2
2
2
2
ration of the solvent under reduced pressure, the crude was evaporation of the solvent under reduced pressure, the crude
purified using column chromatography (SiO , EtOAc/hexane material was purified using column chromatography (SiO
/9 then 2/8) to give estradiol 23a (63 mg, 17%) as a colorless EtOAc/hexane 4/6) to give estradiol 23b (75 mg, 22%) and estra-
2
2
,
1
1
oil. H NMR (CDCl
3
, 500 MHz): δ 0.10 (s, 9H), 0.25 (s, 9H), 0.75 diol 24 (210 mg, 62%). Estradiol 23b: R
s, 3H), 0.97–1.06 (m, 1H), 1.14–1.34 (m, 10H), 1.40–1.63 (m, hexane 4/6), 1 : 1 mixture of two diastereoisomers. H NMR
f 2
= 0.44 (SiO , EtOAc/
1
(
6
2
5
6
1
3
1
H), 1.71–1.73 (m, 1H), 1.82–1.84 (m, 1H), 1.90–1.97 (m, 1H), (CDCl , 500 MHz): δ 0.79 (s, 3H), 0.81 (s, 3H), 1.00–1.03 (m,
3
.27–2.30 (m, 2H), 2.68 (d, J = 16.5 Hz, 1H), 2.84 (dd, J = 16.5, 2H), 1.18–1.74 (m, 54H), 1.83–1.91 (m, 6H), 1.96–2.10 (m, 4H),
.5 Hz, 1H), 3.62–3.66 (m, 3H), 6.54 (d, J = 2.5 Hz, 1H), 2.27–2.31 (m, 4H), 2.73 (dd, J = 16.5, 7.0 Hz, 2H), 2.85–2.89 (m,
13
.61–6.63 (m, 1H), 7.12 (d, J = 8.5 Hz, 1H). C NMR (CDCl3, 2H), 3.48–3.50 (m, 2H), 3.58–3.62 (m, 6H), 3.72–3.76 (m, 2H),
25 MHz): δ 0.4, 0.5, 11.5, 22.9, 25.7, 25.9, 27.4, 28.3, 29.9, 31.0, 3.89–3.97 (m, 4H), 4.65–4.68 (m, 2H), 5.38 (dt, J = 11.8, 3.2 Hz,
2.9, 33.4, 34.8, 37.4, 38.4, 42.1, 43.6, 46.3, 63.2, 81.9, 117.3, 2H), 6.75 (d, J = 2.5 Hz, 2H), 6.84 (d, J = 8.5 Hz, 2H), 7.18 (t, J =
+
13
21.0, 126.8, 132.8, 137.0, 152.9. HRMS-ESI (m/z): [M + Na]
Si , 539.3347; found, 539.3330.
7.7 Hz, 2H). C NMR (CDCl , 125 MHz): δ 11.8, 19.0 (2C),
3
calcd for C30
H52Na
O
1 3
2
19.5, 20.1, 22.7, 22.8, 25.4, 25.7, 25.8, 25.9, 27.3, 27.4, 28.3,
2
3
6
1
8.9, 29.9, 30.6, 31.2, 32.9, 33.3, 33.4, 34.8, 37.5, 38.1, 38.2,
8.3 (2C), 41.8 (2C), 43.0, 43.6, 46.6 (2C), 61.9, 62.2 (2C), 62.9,
3.1, 65.5, 84.3, 86.7, 96.4, 96.6, 96.7, 99.5, 114.0 (2C), 117.5,
2
1
-(((7R,13S,14S,17S)-7-(6-(Benzyloxy)hexyl)-17-(cyclohexyloxy)-
3-methyl-7,8,9,11,12,13,14,15,16,17-decahydro-6H-cyclopenta
[
a]phenanthren-3-yl)oxy)tetrahydro-2H-pyran (22b)
26.9 (2C), 133.1 (2C), 133.2 (2C), 136.9, 155.0, 155.1.
5
9
+
To a solution of 21 (475 mg, 1.03 mmol) in CH Cl (47 mL) HRMS-ESI (m/z): [M + Na] calcd for C H Na O , 563.3707;
2
2
34 52
1 5
was added DHP (470 μL, 5.13 mmol) under nitrogen, followed found, 563.3685.
by a catalytic amount of para-toluene sulfonic acid (2.0 mg,
(
7
7
7R,13S,14S,17S)-13-Methyl-17-((tetrahydro-2H-pyran-2-yl)oxy)-
-(((tetrahydro-2H-pyran-2-yl)oxy)methyl)-
,8,9,11,12,13,14,15,16,17-decahydro-6H-cyclopenta[a]
1
2
mol%). The solution was stirred at room temperature for
hours, then water (50 mL) was added and the reaction
mixture was extracted with CH
organic layers were washed with brine (50 mL), and then dried
Na SO ). After evaporation of the solvent, the residual oil was See procedure for compound 23b. 1 : 1 mixture of two dia-
purified using flash column chromatography (SiO
2 2
Cl (3 × 40 mL). The combined
phenanthren-3-ol (24)
(
2
4
1
2
f 2
, EtOAc/ stereoisomers. R = 0.24 (SiO , EtOAc/hexane 4/6). H NMR
hexane 1/9 then 2/8) to give the title compound as a colorless (CDCl , 300 MHz): δ 0.80 (s, 3H), 0.82 (s, 3H), 0.99–1.06 (m,
3
oil (600 mg, 92%) as a 1 : 1 mixture of 2 diastereoisomers. 2H), 1.20–1.73 (m, 60H), 1.84–1.92 (m, 4H), 1.98–2.08 (m, 4H),
1
3
H NMR (CDCl , 500 MHz): δ 0.79 (s, 3H), 0.81 (s, 3H), 2.25–2.28 (m, 4H), 2.67 (d, J = 16.5 Hz, 2H), 2.84 (d, J = 16.5,
0
1
.97–1.06 (m, 2H), 1.14–1.21 (m, 4H), 1.26–1.78 (m, 44H), 2H), 3.49–3.53 (m, 2H), 3.61 (t, J = 6.6 Hz, 4H), 3.74 (t, J =
.83–1.92 (m, 8H), 1.97–2.10 (m, 4H), 2.27–2.33 (m, 4H), 2.73 8.0 Hz, 2H), 3.90–3.96 (m, 2H), 4.68–4.71 (m, 2H), 6.54 (d, J =
(
4
3
dd, J = 16.5, 6.5 Hz, 2H), 2.85–2.89 (m, 2H), 3.44 (t, J = 6.5 Hz, 2.2 Hz, 2H), 6.62 (dd, J = 8.4, 2.2 Hz, 2H), 7.11 (dd, J = 8.4, 3.3
1
3
H), 3.48–3.54 (m, 4H), 3.58–3.60 (m, 2H), 3.72–3.75 (m, 2H), Hz, 2H). C NMR (CDCl , 125 MHz): δ 11.8, 11.9, 19.3, 19.9,
3
.86–3.94 (m, 6H), 4.49 (s, 4H), 4.64–4.68 (m, 2H), 4.95–4.96 22.7, 22.8, 25.6 (2C), 25.7, 25.9, 27.3, 27.4, 27.5, 28.2, 28.8,
(m, 2H), 5.38 (dt, J = 14.0, 3.0 Hz, 2H), 6.76 (d, J = 2.5 Hz, 2H), 29.8, 31.1, 32.7, 33.3, 33.4, 34.7, 37.5, 38.1, 38.3, 41.9 (2C),
6
2
1
2
3
.84 (d, J = 8.5 Hz, 2H), 7.19 (t, J = 7.7 Hz, 2H), 7.27–7.28 (m, 43.0, 43.5, 46.5, 46.6, 61.9, 62.8, 63.0, 84.5, 86.9, 96.7, 99.5,
1
3
3
H), 7.33–7.34 (m, 8H). C NMR (CDCl , 125 MHz): δ 11.8, 113.0, 116.3, 127.0, 131.6, 131.7, 137.0, 153.9 (2C). HRMS-ESI
+
1.9, 19.0 (2C), 19.5, 19.9, 20.1, 22.7, 22.8, 25.4, 25.6, 25.7, (m/z): [M + Na] calcd for C34
5.8, 26.4, 27.0, 27.3, 27.4 (2C), 28.3, 28.9, 29.8, 29.9, 30.6 (2C), 563.3712.
0.8, 31.2, 33.3, 33.4, 34.8, 37.5, 38.1, 38.2 (2C), 38.3 (2C), 41.8
1 5
H52Na O , 563.3707; found,
1
1-Iodoundec-1-yne (29b)
(2C), 43.0, 43.6, 46.6 (2C), 61.9, 62.1, 62.2, 62.9, 63.1, 70.6,
6
2
7
1
1
2.9, 84.4, 86.7, 94.8, 96.3, 96.6, 96.7, 99.5, 113.9, 114.0, 117.4, According to the literature procedure, to a solution of undec-
17.5, 126.8, 126.9, 127.6, 127.7, 128.4, 133.1 (2C), 10-yn-1-ol (1.00 g, 5.90 mmol) in CH Cl (20 mL) at 0 °C was
33.2, 133.3, 137.0 (2C), 138.8, 155.0, 155.1. HRMS-ESI (m/z): added imidazole (483 mg, 7.10 mmol) and PPh (1.87 g,
2
2
3
+
[M + Na] calcd for C H Na O , 653.4176; found, 653.4163.
7.10 mmol). Then, solid I (1.8 g, 7.1 mmol) was added in por-
41
58
1
5
2
tions. After stirring at room temperature for 4 h, the reaction
6
-((7R,13S,14S,17S)-13-Methyl-3,17-bis((tetrahydro-2H-pyran-2-
was quenched through the addition of a saturated solution of
Na S O (100 mL) and then extracted with CH Cl (3 × 50 mL).
yl)oxy)-7,8,9,11,12,13,14,15,16,17-decahydro-6H-cyclopenta[a]
phenanthren-7-yl)hexan-1-ol (23b)
2
2
3
2
2
The combined organic layers were washed with brine and then
SO ). After evaporation of the solvent under reduced
estradiol 22b (400 mg, 0.63 mmol) in a mixture of THF/EtOH pressure, the crude material was purified using flash chrom-
To a degassed (bubbled with nitrogen for 3 min) solution of dried (Na
2
4
This journal is © The Royal Society of Chemistry 2017
Org. Biomol. Chem.

View Article Online
Paper
Organic & Biomolecular Chemistry
atography (SiO
2
EtOAc/hexane 0.5/99.5) to give the title com- material was purified using an automated chromatography
1
pound as a colorless oil (1.54 g, 93%). H NMR (CDCl3, system (SiO , EtOAc/hexane 7/93 for 5 min then EtOAc/hexane
2
5
7
1
00 MHz): δ 1.30 (s, 6H), 1.37–1.40 (m, 4H), 1.52 (quint., J = 7/93 to 60/40 for 40 min) to give the title compound as a color-
1
.0 Hz, 2H), 1.82 (quint., J = 7.0 Hz, 2H), 1.94 (t, J = 2.5 Hz, less oil (338 mg, 47%). H NMR (CDCl
3
, 500 MHz): δ 0.80 (s,
H), 2.18 (dt, J = 7.0, 2.5 Hz, 2H), 3.19 (t, J = 7.0 Hz, 2H). 3H), 1.16–1.42 (m, 16H), 1.47–1.63 (m, 6H), 1.93 (t, J = 2.7 Hz,
1
3
C NMR (CDCl
3
, 125 MHz): δ 7.5, 18.5, 28.6 (2C), 28.8, 29.1, 1H), 2.00 (dt, J = 12.0, 3.0 Hz, 1H), 2.10–2.12 (m, 2H), 2.17 (dt,
2
9.4, 30.6, 33.7, 68.2, 84.9.
J = 7.0, 3.0 Hz, 2H), 2.35–2.39 (m, 1H), 2.45 (dt, J = 11.5, 3.0
Hz, 1H), 2.70 (dt, J = 11.0, 5.0 Hz, 1H), 3.37 (s, 3H), 3.48 (s,
(
4
[
7S,13S,14S,17S)-3,17-Bis(methoxymethoxy)-13-methyl-7-(pent-
-yn-1-yl)-7,8,9,11,12,13,14,15,16,17-decahydro-6H-cyclopenta
a]phenanthren-6-one (30a)
3
5
1
H), 3.65 (t, J = 8.5 Hz, 1H), 4.66 (dd, JAB = 10.0, 6.5 Hz, 2H),
.20 (s, 2H), 7.19 (dd, J = 8.5, 3.0 Hz, 1H), 7.32 (d, J = 8.5 Hz,
13
H), 7.67 (d, J = 3.0 Hz, 1H). C NMR (CDCl , 125 MHz):
3
5
9
According to the literature procedure, to a cold (0 °C) solu- δ 11.7, 18.5, 22.4, 23.8, 26.7, 27.4, 28.0, 28.6, 28.8, 29.2, 29.6,
tion of estradiol 28 (500 mg, 1.33 mmol) in dry THF (15 mL) 29.8, 37.1, 37.5, 42.4, 43.1, 45.4, 48.8, 55.3, 56.3, 68.2, 84.9,
was added a solution of tBuOK in THF (1 M, 2.0 mL, 86.5, 94.6, 96.2, 114.2, 122.4, 127.3, 132.5, 139.8, 155.8, 200.9
+
1
1
.99 mmol) to give a yellow solution. After stirring at 0 °C for (1 carbon unaccounted for). HRMS-ESI (m/z): [M + Na] calcd
h, the reaction mixture was cooled to −78 °C and a solution for C33H48Na O , 547.3394; found, 547.3400.
1 5
of 5-iodopent-1-yne 29a (300 μL, 2.67 mmol) in anhydrous
THF (5 mL), was added drop-wise. The reaction mixture was
stirred at 0 °C for 2 h, and then for a further 16 h at room
temperature. The reaction was quenched through the addition
(
7
7S,13S,14S,17S)-3,17-Dihydroxy-13-methyl-7-(pent-4-yn-1-yl)-
,8,9,11,12,13,14,15,16,17-decahydro-6H-cyclopenta[a]
phenanthren-6-one (31a)
5
9
of an aqueous saturated solution of NH
extracted with CH Cl (3 × 50 mL). The combined organic (180 mg, 0.41 mmol) in THF (2.6 mL) at 0 °C was added 6 M
layers were washed with brine and then dried (Na SO ). After HCl (2.6 mL). The resulting solution was stirred at room temp-
4
Cl (20 mL) and then According to the literature procedure, to a solution of 30a
2
2
2
4
evaporation of the solvent under reduced pressure, the crude erature for 20 h, and then water (50 mL) was added. The reac-
material was purified using an automated chromatography tion mixture was then extracted with EtOAc (3 × 50 mL). The
system (SiO , EtOAc/hexane 5/95 for 5 min then EtOAc/hexane combined organic layers were washed with brine and then
2
5
/95 to 40/60 for 40 min) to provide the title compound as a dried (Na
2
SO
, 500 MHz): δ 0.79 pressure, the crude material was purified using flash chrom-
s, 3H), 1.31–1.39 (m, 2H), 1.45–1.61 (m, 6H), 1.65–1.69 (m, atography (SiO2 EtOAc/hexane 5/5). The obtained solid con-
H), 1.76–1.89 (m, 1H), 1.90 (t, J = 2.5 Hz, 1H), 1.98–2.02 (m, tained 5% of the epimer, according to analysis using NMR
H), 2.05–2.10 (m, 2H), 2.14–2.24 (m, 2H), 2.35–2.38 (m, 1H), spectroscopy, and was dissolved in hot Et O (15 mL). A solid
4
). After evaporation of the solvent under reduced
1
colorless oil (183 mg, 31%). H NMR (CDCl
(
3
1
1
2
3
2
8
1
4
1
2
.45–2.48 (m, 1H), 2.70 (dt, J = 11.5, 4.5 Hz, 1H), 3.36 (s, 3H), was precipitated through the addition of pentane. Isolation of
.46 (s, 3H), 3.64 (t, J = 8.5 Hz, 1H), 4.64 (dd, JAB = 10.0, 6.5 Hz, the solid via filtration, followed by washing with pentane gave
H), 5.18 (s, 2H), 7.18 (dd, J = 8.5, 2.7 Hz, 1H), 7.31 (d, J = the title compound as a white solid (104 mg, 72%, single
1
3
1
13
.5 Hz, 1H), 7.66 (d, J = 2.7 Hz, 1H). C NMR (CDCl3, isomer according H and C NMR spectroscopic analysis).
1
25 MHz): δ 11.6, 18.1, 22.3, 22.4, 25.9, 26.7, 28.0, 37.1, 37.5, Mp 174 °C. H NMR (CDCl
2.3, 43.1, 45.4, 48.0, 55.3, 56.2, 68.8, 84.1, 86.4, 94.6, 96.2, 1.32–1.39 (m, 3H), 1.47–1.61 (m, 5H), 1.64–1.79 (m, 1H),
14.2, 122.5, 127.3, 132.3, 139.8, 155.9, 200.4. (ESI): [M + Na]
, 463.2455; found, 463.2440.
3
, 500 MHz): δ 0.79 (s, 3H),
+
1.79–1.84 (m, 1H), 1.91 (t, J = 2.5 Hz, 1H), 1.97 (dt, J = 12.5,
3.5 Hz, 1H), 2.08–2.25 (m, 5H), 2.38–2.47 (m, 1H), 2.46–2.49
1 5
calcd for C27H36Na O
(
(
7
m, 1H), 2.71 (dt, J = 11.5, 4.7 Hz, 1H), 3.73–3.80 (m, 1H), 5.67
(
(
7S,13S,14S,17S)-3,17-Bis(methoxymethoxy)-13-methyl-7-
undec-10-yn-1-yl)-7,8,9,11,12,13,14,15,16,17-decahydro-6H-
s, 1H), 7.04 (dd, J = 8.2, 2.7 Hz, 1H), 7.31 (d, J = 8.2 Hz, 1H),
13
3
.57 (d, J = 2.7 Hz, 1H). C NMR (CDCl , 125 MHz): δ 11.0,
cyclopenta[a]phenanthren-6-one (30b)
1
8.2, 22.4, 22.6, 26.0, 26.8, 30.6, 36.6, 37.5, 42.7, 43.5, 45.5,
5
9
According to the literature procedure, to a cold (0 °C) solu- 48.1, 68.9, 81.8, 84.1, 113.6, 121.6, 127.6, 132.3, 138.7, 154.7,
tion of estradiol 28 (520 mg, 1.38 mmol) in dry THF (15 mL) 201.2. HRMS-APCI (m/z): [M + H] calcd for C23
was added a solution of tBuOK in THF (1 M, 2.1 mL, 353.2111; found, 353.2103.
+
29 3
H O ,
2
1
.10 mmol) to give a yellow solution. After stirring at 0 °C for
h the reaction mixture was cooled to −78 °C, and a solution
(
7
7S,13S,17S)-3,17-Dihydroxy-13-methyl-7-(undec-10-yn-1-yl)-
,8,9,11,12,13,14,15,16,17-decahydro-6H-cyclopenta[a]
phenanthren-6-one (31b)
of 11-iodoundec-1-yne 29b (770 mg, 2.76 mmol) in anhydrous
THF (5.0 mL), was added drop-wise. The reaction was stirred at
0
5
9
°C for 2 h, and then stirred for a further 16 h at room temp- According to the literature procedure, to a solution of com-
erature. The reaction was quenched through the addition of an pound 30b (340 mg, 0.77 mmol) in THF (5.0 mL) at 0 °C was
aqueous saturated solution of NH Cl (20 mL) and then added 6 M HCl (5.0 mL). The solution was stirred at room
4
extracted with CH
layers were washed with brine and then dried (Na
evaporation of the solvent under reduced pressure the crude bined organic layers were washed with brine and then dried
2
Cl
2
(3 × 50 mL). The combined organic temperature for 20 h, then water (50 mL) was added. The reac-
2
SO ). After tion mixture was extracted with EtOAc (3 × 50 mL). The com-
4
Org. Biomol. Chem.
This journal is © The Royal Society of Chemistry 2017

View Article Online
Organic & Biomolecular Chemistry
Paper
2 4
(Na SO ). After evaporation of the solvent under reduced (m, 20H), 1.58–1.64 (m, 3H), 1.72–1.74 (m, 1H), 1.89–1.92 (m,
pressure a white solid was obtained (260 mg, 93%) that was 1H), 1.94 (t, J = 3.0 Hz, 1H), 2.10–2.19 (m, 3H), 2.28–2.33 (m,
engaged in the next step without purification. Mp 170 °C. 2H), 2.71 (d, J = 16.5 Hz, 1H), 2.86 (dd, J = 16.5, 5.5 Hz, 1H),
1
H NMR (CDCl
.43–1.61 (s, 6H), 1.84 (br s, 1H), 1.93 (t, J = 2.5 Hz, 1H), 6.63 (dd, J = 8.5, 2.5 Hz, 1H), 7.15 (d, J = 8.5 Hz, 1H). C NMR
.96–1.98 (m, 1H), 2.08 (dt, J = 11.0, 3.5 Hz, 1H), 2.13–2.17 (m, (CDCl , 125 MHz): δ 11.2, 18.5, 22.8, 25.7, 27.4, 28.3, 28.6,
3
, 500 MHz): δ 0.78 (s, 3H), 1.14–1.39 (m, 16H), 3.75 (t, J = 8.5 Hz, 1H), 4.77 (s, 1H), 6.55 (d, J = 2.5 Hz, 1H),
1
3
1
1
3
4
8
1
2
4
1
3
H), 2.37–2.40 (m, 1H), 2.44–2.47 (m, 1H), 2.69 (dt, J = 11.5, 28.9, 29.2, 29.6, 29.8, 30.1, 30.7, 33.3, 34.7, 37.0, 38.2, 42.1,
.5 Hz, 1H), 3.79 (t, J = 8.5 Hz, 1H), 6.76 (s, 1H), 7.07 (dd, J = 43.5, 46.6, 68.2, 82.2, 85.0, 112.9, 116.3, 127.2, 132.1, 137.3,
+
.5, 2.7 Hz, 1H), 7.28 (d, J = 8.5 Hz, 1H), 7.62 (d, J = 2.7 Hz, 153.5. HRMS-ESI (m/z): [M + Na] calcd for C29
H). C NMR (CDCl , 125 MHz): δ 11.0, 18.5, 22.4, 23.9, 26.7, 445.3077; found, 445.3080.
3
H
42Na
1
O
2
,
1
3
7.4, 28.6, 28.8, 29.2, 29.5, 29.8, 30.4, 36.6, 37.4, 42.8, 43.4,
5.4, 48.9, 68.2, 81.8, 85.0, 113.6, 121.7, 127.5, 132.2, 138.5,
2-Azidoethyl 5-formyl-2,4-dimethyl-1H-pyrrole-3-carboxylate (34)
54.9, 202.2 (1 carbon unaccounted for). HRMS-ESI (m/z): To a stirred solution of 5-formyl-2,4-dimethyl-1H-pyrrole-3-
+
38
[M + Na] calcd for C H Na O , 459.2870; found, 459.2854.
carboxylic acid (32, 1.60 g, 9.60 mmol) in dry CH Cl (35 mL)
2 2
29
40
1
3
was added DMAP (1.30 g, 10.6 mmol) and EDCI (1.64 g,
(
7
7R,13S,17S)-13-Methyl-7-(pent-4-yn-1-yl)-
,8,9,11,12,13,14,15,16,17-decahydro-6H-cyclopenta[a]
phenanthrene-3,17-diol (25a)
10.6 mmol), followed by 2-azidoethanol (33, 925 mg,
10.6 mmol) and the resulting solution was heated at reflux
temperature for 2 days. The reaction mixture was then cooled
According to the literature procedure, to a suspension of 31a to room temperature and water (50 mL) was added. The reac-
5
9
(
100 mg, 0.28 mmol) in dry CH Cl (8.0 mL) at 0 °C was added tion mixture was extracted with CH Cl (3 × 40 mL). The com-
2
2
2
2
HSiEt
3
(1.30 mL) followed by BF
3
·OEt
2
(8.0 mL). The reaction bined organic layers were washed with brine (50 mL), then
SO ). After evaporation of the solvent under reduced
a further 4 h at 40 °C. The reaction mixture was then carefully pressure the crude product was purified using flash chromato-
quenched at 0 °C through the addition of a 10% solution of graphy (SiO , EtOAc/hexane 4/6) to give the title compound as
potassium carbonate (20 mL), and extracted with CH Cl (3 × a white solid (1.29 g, 57%). Mp 98 °C. H NMR (CDCl
0 mL). The combined organic layers were washed with brine 500 MHz): δ 2.57 (s, 3H), 2.59 (s, 3H), 3.61 (t, J = 5.0 Hz, 2H),
mixture was stirred at room temperature for 12 h, and then for dried (Na
2
4
2
1
2
2
3
,
2
1
3
and dried (Na
reduced pressure, the crude material was purified using flash (CDCl
chromatography (SiO , EtOAc/hexane 4/6) to give the title com- 143.7, 164.6, 177.5. HRMS-ESI (m/z): [M + Na] calcd for
2
SO
4
). After evaporation of the solvent under 4.41 (t, J = 5.0 Hz, 2H), 9.63 (s, 1H), 9.82 (br s, 1H). C NMR
3
, 125 MHz): δ 10.8, 14.6, 50.3, 62.1, 113.5, 128.5, 136.0,
+
2
1
pound as a white solid (93 mg, 98%). Mp 78 °C. H NMR
10 12 4 1 3
C H N Na O , 259.0802; found, 259.0802.
(
CDCl
3
, 500 MHz): δ 0.79 (s, 3H), 1.10–1.13 (m, 1H), 1.24–1.39
(
Z)-2-Azidoethyl 5-((3-methoxy-5-oxo-1H-pyrrol-2(5H)-ylidene)
(m, 4H), 1.42–1.52 (m, 4H), 1.56–1.72 (m, 3H), 1.76–1.79 (m,
methyl)-2,4-dimethyl-1H-pyrrole-3-carboxylate (36)
1
2
H), 1.89–1.93 (m, 2H), 2.10–2.16 (m, 3H), 2.28–2.34 (m, 2H),
.68 (d, J = 17.0 Hz, 1H), 2.89 (dd, J = 17.0, 5.5 Hz, 1H), 3.76 (t, To a solution of 35
6
4
2 2
(659 mg, 5.83 mmol) in dry CH Cl
J = 8.5 Hz, 1H), 4.77 (br s, 1H), 6.54 (d, J = 2.5 Hz, 1H), 6.63 (190 mL) was added triethylamine (2.2 mL, 15.9 mmol) fol-
13
(
dd, J = 8.5, 2.5 Hz, 1H), 7.15 (d, J = 8.5 Hz, 1H). C NMR lowed by TMSOTf (1.45 mL, 7.95 mmol) at 0 °C. After 20 min,
(CDCl
3
, 125 MHz): δ 11.2, 18.8, 22.8, 25.0, 27.3, 27.4, 30.7, a solution of 34 (600 mg, 2.65 mmol) in dry CH
2
Cl
2
(40 mL)
3
1
3.0, 34.6, 37.0, 38.2, 42.1, 43.6, 46.6, 68.4, 82.2, 84.7, 113.1, was added at 0 °C. The reaction mixture was stirred at this
+
16.3, 127.3, 132.0, 136.9, 153.6. HRMS-APCI (m/z): [M + H]
temperature for 4 hours. The reaction was quenched through
the addition of phosphate buffer (pH = 7, 100 mL). The solu-
tion was extracted with CH Cl (3 × 100 mL). The combined
calcd for C23
H
31
O
2
, 339.2319; found, 339.2314.
2
2
(7R,13S,17S)-13-Methyl-7-(undec-10-yn-1-yl)-
2 4
organic fractions were washed with brine, then dried (Na SO ).
7
,8,9,11,12,13,14,15,16,17-decahydro-6H-cyclopenta[a]
After evaporation of the solvent, the resulting brown oil was
dissolved in THF (230 mL) and concentrated aqueous HCl
phenanthrene-3,17-diol (25b)
5
9
According to the literature procedure, to a suspension of 31b (580 μL, 6.89 mmol) was added. After a few minutes the reac-
50 mg, 0.11 mmol) in dry CH Cl (3.0 mL) at 0 °C was added tion was quenched through the addition of saturated aqueous
HSiEt (0.5 mL) and BF ·OEt (2.0 mL). The reaction mixture NaHCO (200 mL), then extracted with CH Cl (3 × 100 mL).
(
2
2
3
3
2
3
2
2
was stirred at room temperature for 5 h and then carefully The combined organic extracts were washed with water (2 ×
quenched at 0 °C through the addition of a 10% solution of 100 mL). After concentration of the organic fraction under
potassium carbonate (20 mL), and extracted with CH Cl (3 × vacuum, the resulting suspension was washed with water and
2
2
2
0 mL). The combined organic layers were washed with brine hexane, then hot methanol using filtration, to give a yellow
1
and then dried (Na
under reduced pressure, the crude material was purified using δ 2.37 (s, 3H), 2.64 (s, 3H), 3.60 (t, J = 5.0 Hz, 2H), 3.84 (s, 3H),
flash chromatography (SiO , EtOAc/hexane 4/6) to give the title 4.39 (t, J = 5.0 Hz, 2H), 5.02 (s, 1H), 6.32 (s, 1H), 10.64 (s, 1H),
compound as a white solid (40 mg, 87%). Mp 119 °C. H NMR 11.00 (s, 1H). C NMR (CDCl
CDCl , 500 MHz): δ 0.78 (s, 3H), 0.98–1.05 (m, 1H), 1.17–1.54 58.4, 61.7, 90.3, 99.6, 111.8, 122.7, 123.8, 128.3, 142.2, 165.3,
2 4 3
SO ). After evaporation of the solvent solid (360 mg, 41%). Mp 229 °C. H NMR (CDCl , 500 MHz):
2
1
13
3
, 125 MHz): δ 11.5, 14.3, 50.5,
(
3
This journal is © The Royal Society of Chemistry 2017
Org. Biomol. Chem.

View Article Online
Paper
Organic & Biomolecular Chemistry
+
1
68.2, 173.6. HRMS-ESI (m/z): [M
+
Na] calcd for layers were washed with brine (40 mL) and then dried
(Na SO ). After evaporation of the solvents under reduced
C H N Na O , 354.1173; found, 354.1175.
1
5
17
5
1
4
2
4
pressure, the crude material was purified using flash chrom-
atography (Al basic Brockman III, EtOAc/hexane 1/9 then
/8) to give the title compound as a red film (40 mg, 42%).
Following the same procedure and starting from 37a, prodigio-
(
Z)-2-Azidoethyl 2-((5-bromo-3-methoxy-1H-pyrrol-2-yl)
2 3
O
methylene)-3,5-dimethyl-2H-pyrrole-4-carboxylate (37a)
2
To a stirred solution of 36 (390 mg, 1.18 mmol) in dry CH
(
2
Cl
2
1
20 mL) was added POBr
solution was heated at reflux temperature under nitrogen for 500 MHz): δ 2.22 (br s, 3H), 2.40 (s, 3H), 3.55 (t, J = 4.7 Hz,
7 h, then more POBr (200 mg, 0.70 mmol) was added. The 2H), 3.98 (s, 3H), 4.33 (t, J = 4.7 Hz, 2H), 6.06 (s, 1H), 6.21 (s,
resulting solution was heated at reflux temperature under 1H), 6.73 (d, J = 4.0 Hz, 1H), 6.76 (br s, 1H), 6.93 (br s, 1H).
3 3
(670 mg, 2.35 mmol). The resulting sene 26 was isolated in 37% yield. Mp 77 °C. H NMR (CDCl ,
1
3
1
3
nitrogen for 6 h, then was cooled to room temperature. A satu-
rated aqueous solution of NaHCO (30 mL) was added and the 110.8, 112.3, 112.8, 113.8, 123.3, 126.3, 128.3, 131.6, 140.5,
reaction mixture was extracted with CH
combined organic fractions were washed with brine, then C H N O , 381.1670; found, 381.1674.
C NMR (CDCl , 125 MHz): δ 11.7, 13.3, 50.4, 58.7, 61.6, 96.2,
3
3
+
2
2
Cl (3 × 20 mL). The 143.7, 161.0, 165.0, 169.2. HRMS-ESI (m/z): [M + H] calcd for
1
9
21 6 3
dried (Na
product was purified using flash chromatography (Al
Brockman III, CH Cl 100%) to give the title compound as a
2
SO
4
) and the solvent evaporated in vacuo. The crude
2 3
O
basic,
2
2
tert-Butyl 4-(3-hydroxypropyl)-3,5-dimethyl-1H-pyrrole-2-
carboxylate (39)
1
yellow solid (300 mg, 64%). Mp 116 °C. H NMR (CDCl
00 MHz) 2.41 (s, 3H), 2.61 (s, 3H), 3.59 (t, J = 5.0 Hz, 2H), 3.85
s, 3H), 4.39 (t, J = 5.0 Hz, 2H), 5.59 (s, 1H), 6.93 (s, 1H).
3
,
5
6
5
To a solution of 38 (2.00 g, 7.11 mmol) in anhydrous THF
70 mL) was added BH ·THF (1 M in THF, 15.6 mmol) at 0 °C.
(
(
1
3
3
C NMR (CDCl
3
, 125 MHz) 11.7, 15.2, 50.4, 58.7, 61.9, 100.2,
The reaction was stirred at room temperature for 16 h, then
was quenched through addition of 1 M HCl (50 mL) at 0 °C.
The reaction mixture was extracted with EtOAc (3 × 50 mL).
The combined organic layers were washed with brine (40 mL)
1
13.2, 115.7, 126.6, 133.9, 139.5, 144.4, 147.6, 164.9, 167.5.
+
HRMS-ESI (m/z): [M + H] calcd for C H Br N O , 394.0509;
1
5
16
1 5 3
found, 394.0490.
and then dried (Na SO ). After evaporation of the solvents
(Z)-2-Azidoethyl 2-((3-methoxy-5-(((trifluoromethyl)sulfonyl)
2
4
under reduced pressure, a white solid was obtained (1.80 g,
quant). It was used without further purification. H NMR
oxy)-1H-pyrrol-2-yl)methylene)-3,5-dimethyl-2H-pyrrole-4-
carboxylate (37b)
1
(
2
6
1
CDCl , 500 MHz): δ 1.55 (s, 9H), 1.70 (quint., J = 6.9 Hz, 2H),
3
To a suspension of 36 (280 mg, 0.84 mmol) in dry CH Cl
2
2
.20 (s, 3H), 2.24 (s, 3H), 2.45 (t, J = 6.9 Hz, 2H), 3.64 (t, J =
(40 mL) at 0 °C was added, drop-wise, Tf
2
O (400 μL,
1
3
3
.9 Hz, 2H), 8.62 (br s, 1H). C NMR (CDCl , 125 MHz): δ 10.8,
2
.38 mmol). After stirring at this temperature for 4 h, the reac-
1.6, 20.4, 28.7, 33.7, 62.6, 80.3, 118.3, 121.2, 126.3, 129.0,
tion was quenched through the addition of a saturated solu-
tion of NaHCO (70 mL), then extracted with CH Cl (3 ×
0 mL). The combined organic layers were washed with brine
and then dried (Na SO ). After evaporation of the solvent
+
1
61.4. (ESI): [M + Na] calcd for C H N Na O , 276.1570;
1
4
23
1
1 3
3
2
2
found, 276.1557.
5
2
4
under reduced pressure, the crude material was purified using
flash column chromatography (SiO , EtOAc/hexane 2/8 then
/7) to give the title compound as a yellow solid (348 mg,
tert-Butyl 3,5-dimethyl-4-(3-(tosyloxy)propyl)-1H-pyrrole-2-
carboxylate (40)
2
3
8
2
5
1
9%). Mp 117 °C. H NMR (CDCl
3
2 2
, 500 MHz): δ 2.43 (s, 3H), To a solution of 39 (1.80 g, 7.10 mmol) in anhydrous CH Cl
.59 (s, 3H), 3.60 (t, J = 5.0 Hz, 2H), 3.90 (s, 3H), 4.40 (t, J = (70 mL) was added triethylamine (2.5 mL, 17.7 mmol) and
1
3
.0 Hz, 2H), 5.43 (s, 1H), 7.12 (s, 1H), 11.03 (br s, 1H).
C
then pTsCl (1.50 g, 7.80 mmol). The resulting solution was
NMR (CDCl
3
, 125 MHz): δ 11.7, 15.1, 50.3, 59.0, 62.0, 87.7, stirred at room temperature for 16 h and then quenched with
1
1
13.4, 118.8 (q, J C–F = 319 Hz), 119.0, 126.2, 133.7, 135.2, water (50 mL). The reaction mixture was extracted with CH
2
Cl
45.0, 162.1, 164.7, 168.3. HRMS-ESI (m/z): [M + Na] calcd for (3 × 50 mL) and the combined organic layers washed with
Na , 486.0666; found, 486.0678. brine (40 mL) and then dried (Na SO ). After evaporation of
2
+
1
C
16
H
16
F
3
N
5
1
O
6
S
1
2
4
the solvent under reduced pressure, the crude product was
(
Z)-2-Azidoethyl 2-((4-methoxy-1H,1′H-[2,2′-bipyrrol]-5-yl)
purified using flash column chromatography (SiO , EtOAc/
2
methylene)-3,5-dimethyl-2H-pyrrole-4-carboxylate (26)
hexanes 2/8 then 3/7) to give the title compound as a white
1
3
7b (117 mg, 0.25 mmol) was dissolved in DME (4.0 mL), then solid (2.80 g, 97%). Mp 101 °C. H NMR (CDCl
3
, 500 MHz):
LiCl (31 mg, 0.75 mmol) and boronic acid (63 mg, 0.30 mmol) δ 1.54 (s, 9H), 1.75 (quint., J = 6.8 Hz, 2H), 2.13 (s, 3H), 2.16 (s,
were added. The solution was degassed by bubbling with N 3H), 2.40 (t, J = 6.8 Hz, 2H), 2.44 (s, 3H), 4.00 (t, J = 6.8 Hz,
Pd(PPh (29 mg, 10 mol/%) was then added. A degassed 2 M 2H), 7.33 (d, J = 8.0 Hz, 2H), 7.78 (d, J = 8.0 Hz, 2H), 8.58 (br s,
solution of Na CO was added (0.5 mL, 1.00 mmol) and the 1H). C NMR (CDCl , 125 MHz): δ 10.7, 11.5, 19.9, 21.7, 28.7,
2
.
3 4
)
1
3
2
3
3
suspension was stirred at 85 °C for 18 h. After cooling to room 29.9, 70.0, 80.3, 118.4, 119.8, 126.1, 128.0, 129.1, 129.9, 133.4,
+
temperature, the solution was poured into water (15 mL) and 144.8, 161.3. (ESI): [M + Na] calcd for C21
extracted with CH Cl (3 × 20 mL). The combined organic 430.1659; found, 430.1652.
29 1 1 5 1
H N Na O S ,
2
2
Org. Biomol. Chem.
This journal is © The Royal Society of Chemistry 2017

View Article Online
Organic & Biomolecular Chemistry
Paper
tert-Butyl 4-(3-azidopropyl)-3,5-dimethyl-1H-pyrrole-2-
carboxylate (41)
concentration of the combined organic fractions under
vacuum, the resulting suspension was washed with water and
hexane to give the title compound as a yellow solid (1.00 g,
To a solution of 40 (2.80 g, 6.90 mmol) in anhydrous DMF
1
80%). Mp 202 °C. H NMR (CDCl
3
, 500 MHz): δ 1.74 (quint.,
(
(
50 mL) was added triethylamine (10 drops) and then NaN3
3.90 g, 20 mmol). The resulting solution was stirred at room
J = 7.1 Hz, 2H), 2.12 (s, 3H), 2.35 (s, 3H), 2.48 (t, J = 7.1 Hz,
2
1
H), 3.27 (t, J = 7.1 Hz, 2H), 3.90 (s, 3H), 5.10 (d, J = 1.0 Hz,
H), 6.36 (s, 1H), 10.20 (br s, 1H), 10.86 (br s, 1H). C NMR
temperature for 16 h, and then quenched with water (150 mL).
The reaction mixture was extracted with EtOAc (3 × 50 mL) and
the combined organic layers washed with water (40 mL), brine
1
3
(
CDCl , 125 MHz): δ 9.7, 11.5, 21.3, 29.7, 50.9, 58.3, 89.8,
3
1
00.6, 119.6, 121.9, 122.0, 125.6, 132.4, 168.0, 173.3. (ESI):
2 4
(40 mL) and then dried (Na SO ). Evaporation of the solvent
+
[M + Na] calcd for C15
H
19
N
5
1 2
Na O , 324.1431; found, 324.1441.
under reduced pressure gave a white solid (1.6 g, 84%) that
1
was used without further purification. Mp 68 °C. H NMR
(Z)-2-((4-(3-Azidopropyl)-3,5-dimethyl-2H-pyrrol-2-ylidene)
(
CDCl , 500 MHz): δ 1.56 (s, 9H), 1.71 (quint., J = 7.1 Hz, 2H),
3
methyl)-5-bromo-3-methoxy-1H-pyrrole (44)
2
.19 (s, 3H), 2.24 (s, 3H), 2.45 (t, J = 7.1 Hz, 2H), 3.25 (t, J =
1
3
7
.1 Hz, 2H), 8.46 (br s, 1H). C NMR (CDCl
3
, 125 MHz): δ 10.7,
To a stirred solution of dipyrrinone 43 (500 mg, 1.66 mmol) in
1
1
1.6, 21.1, 28.7, 29.7, 50.8, 80.4, 118.5, 120.3, 126.2, 128.9,
61.3. (ESI): [M + Na] calcd for C H N Na O , 301.1635;
14 22 4 1 2
2 2 3
dry CH Cl (30 mL) was added POBr (950 mg, 3.32 mmol).
The resulting solution was heated at reflux temperature under
+
found, 301.1637.
nitrogen for 17 h, and then more POBr (950 mg, 3.32 mmol)
3
was added. The resulting solution was heated at reflux temp-
erature under nitrogen for an additional 20 h, and then was
cooled to room temperature. A saturated aqueous solution of
4
-(3-Azidopropyl)-3,5-dimethyl-1H-pyrrole-2-carbaldehyde (42)
To a stirred solution of 41 (540 mg, 1.90 mmol) in CH Cl
2
2
3
NaHCO (30 mL) was added and the reaction mixture was
(25 mL), was added TFA (3.8 mL, 52.0 mmol) at 0 °C. The reac-
extracted with CH Cl (3 × 20 mL). The combined organic frac-
tion mixture was stirred for 1 h at room temperature, then
TMOF (1.9 mL, 17.1 mmol) was added at 0 °C. After stirring
for a further 20 min at room temperature, the reaction was
2
2
tions were washed with brine, dried (Na SO ) and the solvent
2
4
evaporated in vacuo. The crude product was purified using
flash chromatography (Al O basic, Brockman III, EtOAc/
quenched through the addition of water (10 mL) and NaHCO
3
2 3
hexanes 1/9) to give the title compound as an orange solid
solid until gassing stopped. The reaction mixture was then
extracted with CH Cl (3 × 30 mL) and the combined organic
1
(
310 mg, 51%). Mp 72 °C. H NMR (CDCl
3
, 500 MHz): δ 1.72
2
2
(
q, J = 7.0 Hz, 2H), 2.14 (s, 3H), 2.29 (s, 3H), 2.46 (t, J = 7.0 Hz,
2 4
layers washed with brine (30 mL) and then dried (Na SO ).
2
1
5
H), 3.26 (t, J = 7.0 Hz, 2H), 3.83 (s, 3H), 5.58 (s, 1H), 6.88 (s,
After evaporation of the solvent under reduced pressure the
crude material was purified using flash column chromato-
1
3
H). C NMR (CDCl
3
, 125 MHz): δ 9.6, 12.4, 21.1, 29.5, 50.8,
8.5, 99.4, 116.3, 121.9, 126.5, 131.4, 137.0, 137.4, 144.1, 166.9.
graphy (SiO
pound as a white solid (270 mg, 70%). Mp 50 °C. H NMR
CDCl , 500 MHz): δ 1.73 (quint., J = 7.2 Hz, 2H), 2.26 (s, 3H),
2
, EtOAc/hexanes 2/8 then 3/7) to give the title com-
+
1
(
ESI): [M + H] calcd for C H BrN O , 364.0767; found,
15 19 5 1
3
64.0.757.
(
3
2
9
5
.27 (s, 3H), 2.47 (t, J = 7.2 Hz, 2H), 3.27 (t, J = 6.5 Hz, 2H),
1
3
.48 (s, 2H). C NMR (CDCl , 125 MHz): δ 8.9, 11.8, 20.8, 29.5, (Z)-5-((4-(3-Azidopropyl)-3,5-dimethyl-2H-pyrrol-2-ylidene)
3
+
0.8, 121.5, 128.2, 132.1, 135.5, 176.0. (ESI): [M + Na] calcd for methyl)-4-methoxy-1H,1′H-2,2′-bipyrrole (27)
10 14 4 1
C H N NaO , 229.1060; found, 229.1062.
The bromo-dipyrrin 43 (310 mg, 0.85 mmol) was dissolved in
DME (14 mL). LiCl (107 mg, 2.55 mmol) and boronic acid
(
Z)-5-((4-(3-Azidopropyl)-3,5-dimethyl-1H-pyrrol-2-yl)
(
215 mg, 1.02 mmol) were added. The solution was degassed
methylene)-4-methoxy-1H-pyrrol-2(5H)-one (43)
by bubbling with N . Pd (PPh ) (98 mg, 10 mol/%) was then
2
3 4
6
4
To a solution of 35
300 mL) was added triethylamine (3.4 mL, 24.7 mmol) and 3.40 mmol) and the suspension was stirred at 85 °C for 18 h.
TMSOTf (2.25 mL, 12.4 mmol) at 0 °C. After 20 min, a solution After cooling to room temperature, the mixture was poured
of 42 (850 mg, 4.12 mmol) in dry CH Cl (60 mL) was added at into water (15 mL) and extracted with EtOAc (3 × 20 mL). The
°C. The reaction mixture was stirred at this temperature for combined organic layers were washed with brine (40 mL) and
hours and then quenched through the addition of phosphate then dried (Na SO ). After evaporation of the solvent under
(1.00 g, 9.07 mmol) in dry CH
2
Cl
2
2 3
added. A degassed 2 M solution of Na CO was added (1.7 mL,
(
2
2
0
4
2
4
buffer (pH = 7, 100 mL). The mixture was extracted with reduced pressure, the crude material was purified using flash
CH Cl (3 × 100 mL). The combined organic fractions were chromatography (Al basic Brockman III, EtOAc/hexane 0.5/
washed with brine and then dried (Na SO ). After evaporation 9.5, 1/9 then 2/8) to give the title compound as a red film
2
2
2 3
O
2
4
1
of the solvent the resulting brown oil was dissolved in THF (110 mg, 37%). Mp 70 °C. H NMR (CDCl
230 mL) and concentrated aqueous HCl (900 μL, 10.7 mmol) (quint., J = 7.0 Hz, 2H), 1.69 (s, 3H), 2.13 (s, 3H), 2.32 (t, J =
was added. After a few minutes the reaction was quenched 7.0 Hz, 2H), 3.16 (t, J = 7.0 Hz, 2H), 3.99 (s, 3H), 6.11–6.13 (m,
3
, 500 MHz): δ 1.62
(
1
3
through the addition of saturated aqueous NaHCO
then extracted with CH Cl (3 × 100 mL). The combined (CDCl
organic extracts were washed with water (2 × 100 mL). After 109.8, 112.2, 113.2, 121.0, 122.7, 125.6, 128.8, 129.5, 136.8,
3
(200 mL), 2H), 6.59 (s, 1H), 6.67 (d, J = 3.0 Hz, 1H), 6.93 (s, 1H). C NMR
2
2
3
, 125 MHz): δ 9.7, 10.1, 21.1, 29.5, 50.8, 58.5, 95.5,
This journal is © The Royal Society of Chemistry 2017
Org. Biomol. Chem.

View Article Online
Paper
Organic & Biomolecular Chemistry
+
1
37.3, 159.2, 168.9. HRMS-ESI (m/z): [M + H] calcd for (Z)-3-(4-(3-((7R,13S,14S,17S)-3,17-Dihydroxy-13-methyl-
C H N O , 351.1928; found, 351.1924. 7,8,9,11,12,13,14,15,16,17-decahydro-6H-cyclopenta[a]
1
9
23 6 1
phenanthren-7-yl)propyl)-1H-1,2,3-triazol-1-yl)propyl 2-((4-
methoxy-1H,1′H-[2,2′-bipyrrol]-5-yl)methylene)-3,5-dimethyl-
2H-pyrrole-4-carboxylate (46a)
Zinc complex 45
To a solution of prodigiosene 26 (195 mg, 0.51 mmol) in Obtained using GP1, estradiol 25a and prodigiosene complex 45
CHCl3 (55 mL) was added a solution of Zn(OAc) ·2 H O (27 mg, 0.032 mmol). The crude material was purified using
2
2
(
280 mg, 1.28 mmol) and NaOAc·3H
MeOH (14 mL). After stirring at room temperature for 16 h, hexane 5/5, then CH
water (50 mL) was added and the solution was extracted with compound as a red glass (26 mg, 55%). H NMR (CDCl3,
CH Cl (3 × 50 mL). The combined organic layers were washed 500 MHz): δ 0.75 (s, 3H), 1.09–1.32 (m, 9H), 1.47–1.63 (m, 4H),
with water (20 mL) and brine (20 mL), and then dried 1.67–1.79 (m, 1H), 1.86 (d, J = 13.0 Hz, 1H), 2.10–2.17 (m, 4H),
Na SO ). After concentration of the solvent under reduced 2.24–2.28 (m, 2H), 2.34 (s, 3H), 2.50–2.56 (m, 1H), 2.61 (d, J =
2
O (188 mg, 1.38 mmol) in flash chromatography (Al
2 3
O neutral Brockman III, EtOAc/
2
Cl /MeOH 99/1 to 90/10) to give the title
2
1
2
2
(
2
4
pressure, the residue was triturated in MeOH, the solid iso- 16.0 Hz, 1H), 2.74–2.84 (m, 2H), 3.72 (t, J = 8.5 Hz, 1H), 3.97 (s,
lated via filtration (Millipore®), and the solid then washed 3H), 4.57–4.63 (m, 4H), 6.01 (s, 1H), 6.26–6.27 (m, 1H), 6.53 (br
three times with MeOH to produce the desired compound as a s, 1H), 6.58 (d, J = 5.0 Hz, 1H), 6.79 (br s, 1H), 6.90 (s, 1H), 6.94
1
3
dark red solid (127 mg, 60%). Mp 238 °C with decomposition. (br s, 1H), 7.04 (d, J = 8.0 Hz, 1H), 7.19 (s, 1H). C NMR (CDCl
3
,
1
H NMR (CDCl
3
, 500 MHz): δ 2.18 (s, 6H), 2.56 (s, 6H), 3.54 (t, 125 MHz): δ 11.3, 11.6, 14.2, 22.8, 25.6, 26.2, 27.4, 28.3, 29.8,
J = 5.0 Hz, 4H), 3.98 (s, 6H), 4.31 (t, J = 5.0 Hz, 4H), 6.05 (s, 30.7, 33.5, 34.8, 37.1, 38.7, 42.3, 43.6, 46.7, 49.4, 58.8, 61.7, 82.1,
2
9
5
1
H), 6.10–6.11 (m, 2H), 6.50 (s, 2H), 6.61 (s, 2H), 7.34 (s, 2H), 95.4, 111.3, 112.0, 112.8, 114.0, 115.4, 117.1, 121.2, 125.0, 125.8,
1
3
.21 (br s, 2H). C NMR (CDCl
8.5, 61.5, 96.1, 110.7, 114.4, 116.1, 118.0, 123.1, 126.4, unaccounted for). HRMS-ESI (m/z): [M
32.0, 133.0, 141.0, 155.7, 156.6, 165.3, 167.1. HRMS-APCI , 719.3915; found, 719.3908.
3
, 125 MHz): δ 12.3, 17.1, 50.4, 125.9, 127.3, 130.6, 136.7, 148.6, 155.3, 164.7, 168.4 (3 carbons
+
+
H] calcd for
42 51 6 5
C H N O
+
(
39 12 6 1
m/z): [M + H] calcd for C38H N O Zn , 823.2402; found,
8
23.2398.
(Z)-3-(4-(9-((7R,13S,14S,17S)-3,17-Dihydroxy-13-methyl-
,8,9,11,12,13,14,15,16,17-decahydro-6H-cyclopenta[a]
7
phenanthren-7-yl)nonyl)-1H-1,2,3-triazol-1-yl)propyl 2-((4-
methoxy-1H,1′H-[2,2′-bipyrrol]-5-yl)methylene)-3,5-dimethyl-
Zinc complex 47
This compound was obtained following the procedure above,
using prodigiosene 27. After concentration of the solvent Obtained using GP1, estradiol 25b and prodigiosene complex 45
under reduced pressure the residue was dissolved in Et O. The (27 mg, 0.032 mmol). The crude material was purified using
desired compound was precipitated by the addition of hexanes flash chromatography (Al O neutral Brockman III, EtOAc/hexane
2
H-pyrrole-4-carboxylate (46b)
2
2
3
and then isolated, as a red solid, via filtration (Millipore®) 5/5, then CH Cl /MeOH 99/1 to 90/10) to give the title compound
2
2
1
1
(
3 3
81 mg, 68%). Mp 102 °C. H NMR (CDCl , 500 MHz): as a red glass (30 mg, 57%). H NMR (CDCl , 500 MHz): δ 0.76 (s,
δ 1.64 (quint., J = 7.0 Hz, 4H), 1.87 (s, 6H), 2.23 (s, 6H), 2.39 (t, 3H), 0.84–0.92 (m, 1H), 0.97–1.02 (m, 1H), 1.14–1.47 (m, 22H),
J = 7.0 Hz, 4H), 3.12 (t, J = 7.0 Hz, 4H), 3.95 (s, 6H), 1.56–1.63 (m, 4H), 1.68–1.70 (m, 1H), 1.88 (d, J = 12.5 Hz, 1H),
6
.04–6.05 (m, 4H), 6.39 (s, 2H), 6.48 (s, 2H), 7.20 (s, 2H), 9.25 2.08–2.12 (m, 1H), 2.26–2.27 (m, 3H), 2.30 (s, 3H), 2.64–2.70 (m,
1
3
(br s, 2H). C NMR (CDCl , 125 MHz): δ 10.1, 14.5, 21.7, 29.3, 3H), 2.81 (dd, J = 16.5, 5.0 Hz, 1H), 3.72 (t, J = 8.5 Hz, 1H), 3.96
3
5
1
0.8, 58.2, 95.0, 109.7, 111.4, 117.5, 121.2, 126.4, 127.5, (s, 3H), 4.62–4.66 (m, 4H), 6.02 (s, 1H), 6.26 (br s, 1H), 6.54 (d, J =
28.5, 134.2, 136.8, 151.2, 154.4, 165.0. HRMS-ESI (m/z): 2.5 Hz, 1H), 6.63 (dd, J = 8.5, 2.5 Hz, 1H), 6.75 (br s, 1H), 6.88 (s,
+
13
[M + Na] calcd for C H N Na O Zn , 785.2737; found, 1H), 7.10 (d, J = 8.5 Hz, 1H), 7.31 (s, 1H). C NMR (CDCl3,
38 42 12 1 2 1
7
85.2743.
125 MHz): δ 11.2, 11.7, 13.8, 22.8, 25.4, 25.6, 27.4, 27.8, 29.1, 29.2
2C), 29.5, 29.6, 29.8, 30.7, 32.1, 33.5, 34.9, 37.1, 38.4, 42.2, 43.5,
6.7, 49.4, 58.7, 61.7, 82.1, 95.9, 111.0, 111.1, 112.0, 112.5, 113.3,
114.4, 116.4, 121.3, 123.9, 126.3, 127.1, 127.7, 128.1, 129.2, 131.3,
(
4
8
6
General procedure 1 (GP1) for the CuACC reaction
To a solution of estradiol 25a or 25b (0.028 mmol) in a mixture
of a CH Cl /MeOH (1/0.4 mL) was added sodium ascorbate
0.028 mmol), prodigiosene complex 45 or 47 (0.028 mmol)
and TBTA (10 mol%), followed by CuSO ·5 H O (0.028 mmol).
+
137.0, 148.7, 154.4, 164.8, 168.8. HRMS-ESI (m/z): [M + H] calcd
for C H N O , 803.4854; found, 803.4818.
48 63 6 5
2
2
(
(
7R,13S,14S,17S)-7-(3-(1-(3-((Z)-2-((4-Methoxy-1H,1′H-[2,2′-
4
2
bipyrrol]-5-yl)methylene)-3,5-dimethyl-2H-pyrrol-4-yl)propyl)-
After stirring at room temperature for 2 days, water (20 mL)
was added and the reaction mixture was extracted with CH Cl
3 × 20 mL). The combined organic layers were washed with
HCl 1 M (50 mL) and brine, and then dried (Na SO ). After
evaporation of the solvent under reduced pressure the crude Obtained using GP1, estradiol 25a and prodigiosene complex
1
7
H-1,2,3-triazol-4-yl)propyl)-13-methyl-
,8,9,11,12,13,14,15,16,17-decahydro-6H-cyclopenta[a]
2
2
(
phenanthrene-3,17-diol (48a)
2
4
material was purified using flash chromatography.
47 (25 mg, 0.032 mmol). The crude material was purified
Org. Biomol. Chem.
This journal is © The Royal Society of Chemistry 2017

View Article Online
Organic & Biomolecular Chemistry
Paper
1
using flash chromatography (Al
hexane 3/7 up to 100% EtOAc with increments of 10%, then 500 MHz): δ 0.10 (s, 6H), 0.22 (s, 6H), 0.91–0.94 (m, 15H), 1.00
CH Cl /MeOH 98/2 up to 95/5) to give the title compound as a (s, 9H), 2.30 (s, 3H), 2.37 (s, 3H), 2.42 (s, 3H), 2.46–2.50 (s, 6H),
red glass (26 mg, 58%). H NMR (CDCl
2 3 3
O basic Brockman III, EtOAc/ (540 mg, 85%) of two diastereoisomers. H NMR (CDCl ,
2
2
1
3
, 500 MHz): δ 0.75 (s, 2.58 (t, J = 5.5 Hz, 2H), 2.63–2.67 (m, 4H), 2.73 (q, J = 5.5 Hz,
H), 0.83–0.94 (m, 1H), 1.04–1.12 (m, 1H), 1.18–1.32 (m, 4H), 4H), 2.83 (t, J = 5.5 Hz, 2H), 3.92 (t, J = 6.0 Hz, 2H), 4.08 (t, J =
.39–1.48 (m, 2H), 1.54–1.62 (m, 2H), 1.74 (s, 4H), 1.85–1.94 6.0 Hz, 2H), 6.47 (d, J = 8.5 Hz, 2H), 6.53 (d, J = 9.0 Hz, 2H),
3
1
(m, 3H), 2.04–2.07 (m, 4H), 2.17 (s, 3H), 2.26–2.27 (m, 4H), 6.70 (d, J = 9.0 Hz, 2H), 6.76 (d, J = 9.0 Hz, 2H), 6.81 (d, J =
2
1
6
6
.55–2.64 (m, 2H), 2.72–2.78 (m, 1H), 2.83 (dd, J = 16.7, 4.2 Hz, 8.5 Hz, 2H), 6.88 (d, J = 9.0 Hz, 2H), 7.08–7.18 (m, 14H).
1
3
H), 3.69 (t, J = 8.5 Hz, 1H), 3.97 (s, 3H), 4.14–4.15 (m, 2H),
3
C NMR (CDCl , 125 MHz): δ −4.3, −4.2, 13.8, 18.3, 25.8, 29.0,
.05 (s, 1H), 6.18 (br s, 1H), 6.52–6.54 (m, 2H), 6.69 (br s, 1H), 29.2, 36.3, 36.4, 43.2, 49.3, 49.4, 56.4, 56.5, 57.0, 57.1, 65.9,
13
.74 (br s, 1H), 6.89 (s, 1H), 7.01–7.04 (m, 2H). C NMR 66.2, 113.4, 114.1, 119.1, 119.6, 126.0 (2C), 127.8, 127.9, 129.8,
, 125 MHz): δ 9.8, 11.3, 14.3, 21.0, 22.8, 25.3, 26.0, 27.4, 130.7 (2C), 132.0, 132.1, 136.1, 136.5, 136.6, 136.9, 138.0,
(CDCl
3
2
4
1
1
8.0, 30.6, 30.8, 31.0, 33.5, 34.8, 37.0, 38.4, 42.2, 43.6, 46.6, 138.1, 141.1, 141.2, 142.7, 142.8, 153.6, 154.4, 156.7, 157.5.
+
9.6, 58.6, 82.1, 95.1, 110.3, 112.9, 113.1, 113.7, 116.8, 120.6, HRMS-ESI (m/z): [M + H] calcd for C H N O Si , 545.3558;
3
4
49
2
2
1
20.9, 123.1, 125.8, 127.1, 128.1, 130.7, 136.6, 148.3, 155.1, found, 545.3539.
68.3, 207.0 (3 carbons unaccounted for). HRMS-ESI (m/z):
+
General procedure 2 (GP2) for amide coupling
Compound 50 (75 mg, 0.14 mmol) was dissolved in anhydrous
CH Cl (15 mL). DMAP (16 mg, 0.14 mmol), HBTU (50 mg,
.14 mmol) and prodigiosene 1a–c (0.11 mmol) were added.
[M + H] calcd for C H N O , 689.4174; found, 689.4164.
42 53 6 3
(7R,13S,14S,17S)-7-(9-(1-(3-((Z)-2-((4-Methoxy-1H,1′H-[2,2′-
2
2
bipyrrol]-5-yl)methylene)-3,5-dimethyl-2H-pyrrol-4-yl)propyl)-
0
1
7
H-1,2,3-triazol-4-yl)nonyl)-13-methyl-
After stirring at room temperature for 18 h, water (30 mL) was
added to the reaction mixture, which was then extracted with
CH Cl (3 × 25 mL). The combined organic layers were washed
,8,9,11,12,13,14,15,16,17-decahydro-6H-cyclopenta[a]
phenanthrene-3,17-diol (48b)
2
2
Obtained using GP1, estradiol 25b and prodigiosene complex with brine (50 mL), and then dried (Na
7 (25 mg, 0.032 mmol). The crude material was purified mixture was concentrated and purified using column chrom-
using flash chromatography (Al O basic Brockman III, EtOAc/ atography on Brockman III neutral alumina (EtOAc/hexane
2 4
SO ). The crude
4
2
3
hexane 2/8 up to 100% EtOAc with increments of 5%, then 6/4). The orange film obtained was dissolved in a mixture of
CH Cl /IPA 99/1 up to 90/10) to give a red glass (23 mg, 46%). MeOH/CHCl (3/3 mL) and concentrated HCl (15 eq.) was
H NMR (CDCl , 500 MHz): δ 0.77 (s, 3H), 0.85–0.90 (m, 1H), added. The reaction mixture was stirred for 8 h and then a
2
2
3
1
3
0
1
1
.98–1.04 (m, 1H), 1.16–1.40 (m, 18H), 1.43–1.50 (m, 2H), saturated solution of NaHCO
.56–1.65 (m, 4H), 1.68–1.71 (m, 1H), 1.83–1.90 (m, 3H), extracted with CH Cl (3 × 25 mL). The combined organic
.94–1.98 (m, 2H), 2.09 (s, 4H), 2.26–2.30 (m, 4H), 2.64–2.69 layers were washed with brine (50 mL), and then dried
SO ). The crude mixture was concentrated and purified
3
was added and the mixture
2
2
(m, 3H), 2.82 (dd, J = 16.7, 4.7 Hz, 1H), 3.73 (t, J = 8.5 Hz, 1H), (Na
2
4
3
1
8
1
2
4
1
1
.96 (s, 3H), 4.22 (t, J = 6.7 Hz, 2H), 6.05 (s, 1H), 6.17 (br s, using column chromatography on Brockman III neutral
H), 6.57 (s, 1H), 6.62–6.72 (m, 3H), 6.89 (s, 1H), 7.09 (d, J = alumina (EtOAc/hexane 6/4, then CH Cl /MeOH 9/1).
2
2
1
3
3
.5 Hz, 1H), 7.18 (s, 1H). C NMR (CDCl , 125 MHz): δ 9.8,
N-(2-((2-(4-(1-(4-Hydroxyphenyl)-2-phenylbut-1-en-1-yl)
phenoxy)ethyl)(methyl)amino)ethyl)-4-(2-((4-methoxy-1H,1′H-
2,2′-bipyrrol]-5-yl)methylene)-3,5-dimethyl-2H-pyrrol-4-yl)-N-
1.0, 11.3, 21.2, 22.8, 25.4, 25.6, 27.4, 27.8, 29.1, 29.2, 29.3,
9.4, 29.6, 29.8, 30.7, 31.0, 33.5, 34.9, 37.1, 38.4, 42.3, 43.6,
6.7, 49.8, 58.5, 82.2, 95.1, 110.3, 112.7, 113.2, 113.6, 116.7,
20.7, 120.9, 123.0, 125.9, 127.0, 128.1, 129.2, 130.9, 136.9,
[
methyl-4-oxobutanamide (51a)
48.4, 155.0, 168.4 (3 carbons unaccounted for). HRMS-ESI Obtained using GP2 and prodigiosene 1a. Orange glass
+
(m/z): [M + H] calcd for C48
65 6 3
H N O , 773.5113; found, 773.5108.
(32 mg, 61%). Formed as 1 : 1 mixture of E and Z isomers:
H NMR (CDCl , 500 MHz): δ 0.87–0.92 (m, 6H), 2.21–2.25 (m,
3
1
1
N -(2-(4-(1-(4-((tert-Butyldimethylsilyl)oxy)phenyl)-2-phenylbut-
4
4
H), 2.31 (s, 2H), 2.34 (s, 2H), 2.38–2.40 (m, 8H), 2.44–2.48 (m,
H), 2.55–2.76 (m, 10H), 2.81–2.86 (m, 4H), 2.89 (s, 1H), 2.93
1
2
1
-en-1-yl)phenoxy)ethyl)-N ,N -dimethylethane-1,2-diamine
(50)
(
s, 1H), 2.97–3.02 (m, 6H), 3.05 (s, 2H), 3.43 (t, J = 6.2 Hz, 2H),
Compound 49 (500 mg, 1.16 mmol) was dissolved in an- 3.47 (t, J = 7.0 Hz, 2H), 3.87 (t, J = 5.7 Hz, 2H), 3.91 (t, J =
hydrous CH Cl (50 mL). TBSCl (440 mg, 2.8 mmol) and imid- 7.0 Hz, 1H), 3.95 (s, 3H), 3.97 (s, 3H), 4.03 (t, J = 5.7 Hz, 1H),
7
7
2
2
azole (340 mg, 5.6 mmol) were added and the reaction mixture 4.06 (t, J = 5.7 Hz, 1H), 6.03–6.05 (m, 2H), 6.23–6.25 (m, 2H),
was then stirred at room temperature for 24 h, before 6.42 (t, J = 8.5 Hz, 2H), 6.47–6.50 (m, 2H), 6.62–6.65 (m, 2H),
being quenched with water (50 mL) and extracted with CH
2
Cl
2
6.69 (t, J = 8.5 Hz, 2H), 6.75–6.77 (m, 4H), 6.80–6.83 (m, 4H),
(
3 × 50 mL). The combined organic layers were washed with 6.92 (d, J = 9.5 Hz, 2H), 7.00 (t, J = 8.5 Hz, 2H), 7.06–7.10 (m,
1
3
brine (50 mL) and then dried (Na SO ). After evaporation of 8H), 7.12–7.15 (m, 4H). C NMR (CDCl , 125 MHz): δ 12.6,
2
4
3
the solvent under reduced pressure, the crude mixture was 13.7, 13.8, 14.9 (2C), 26.8, 26.9, 27.4, 29.0, 29.1, 29.2, 29.8,
purified using flash chromatography (SiO , CH Cl /MeOH 34.3, 34.4, 36.2, 37.7, 37.8, 38.8, 43.2, 43.5, 43.6, 46.0, 46.1,
/1 + 2% Et N) to give the title compound as a yellow oil 48.4, 54.9 (2C), 55.6, 55.7, 56.3, 56.4, 56.7, 56.8, 58.7, 65.7,
2
2
2
9
3
This journal is © The Royal Society of Chemistry 2017
Org. Biomol. Chem.

View Article Online
Paper
Organic & Biomolecular Chemistry
+
6
1
1
66 5 5
5.9, 66.2, 95.7, 111.0 (2C), 112.2, 112.3, 113.4, 114.1, 114.7, HRMS-ESI (m/z): [M + H] calcd for C54H N O , 864.5058;
15.5, 115.6, 125.9, 127.9 (3C), 129.8, 130.7 (2C), 130.8, 132.0, found, 864.5046.
32.1, 132.2, 135.3, 135.5, 136.1, 136.2, 136.6, 136.7, 138.1
(2C), 140.6, 140.7, 142.8, 142.9, 154.5, 154.6, 155.6, 155.7,
1
56.7, 157.4, 157.5, 168.6, 172.3, 172.5, 172.6, 196.1. HRMS-ESI
+
Acknowledgements
(
m/z): [M + H] calcd for C48H N O , 780.4119; found,
54 5 5
7
80.4124.
The authors thank Dr Md Imam Uddin for laboratory support
in the early stages of this research. During the completion of
this work, EM was supported by a trainee award from The
Beatrice Hunter Cancer Research Institute (BHCRI) with funds
provided by Cancer Care Nova Scotia as part of The Terry Fox
Foundation Strategic Health Research Training Program in
N-(2-((2-(4-(1-(4-Hydroxyphenyl)-2-phenylbut-1-en-1-yl)
phenoxy)ethyl)(methyl)amino)ethyl)-6-(2-((4-methoxy-1H,1′H-
[2,2′-bipyrrol]-5-yl)methylene)-3,5-dimethyl-2H-pyrrol-4-yl)-N-
methyl-6-oxohexanamide (51b)
Obtained using GP2 and 1b. Orange glass (70 mg, 75%). Cancer Research at CIHR. This work was supported by CIHR
1
Formed as 1 : 1 mixture of E and Z isomers: H NMR (CDCl , (133110), BHCRI and the Nova Scotia Health Research
3
5
00 MHz): δ 0.88–0.93 (m, 6H), 1.64–1.69 (m, 8H), 2.25–2.28 Foundation. AT is a BHCRI Senior Scientist and a Faculty of
(m, 8H), 2.31–2.44 (m, 14H), 2.49–2.54 (m, 4H), 2.69–2.75 (m, Science Killam Professor. Human cell-line screening and
8
3
6
6
H), 2.83–2.85 (m, 2H), 2.89–2.99 (m, 6H), 3.31–3.50 (m, 4H), in vivo toxicity evaluations were performed by the
.85–3.88 (m, 2H), 3.96 (s, 3H), 3.97 (s, 3H), 4.01–4.04 (m, 2H), Developmental Therapeutics Program, Division of Cancer
.04 (d, J = 7.5 Hz, 2H), 6.26 (br s, 2H), 6.42–6.49 (m, 4H), Treatment and Diagnosis, National Cancer Institute according
.64–6.94 (m, 14H), 7.02 (t, J = 8.0 Hz, 2H), 7.07–7.15 (m, 12H). to posted procedures (http://dtp.cancer.gov).
1
3
3
C NMR (CDCl , 125 MHz): δ 12.5, 13.8, 14.4, 24.0, 24.1, 25.0,
2
4
5
1
1
1
1
1
5.3, 29.1, 29.2, 32.9, 33.0, 33.6, 34.1, 34.2, 36.3, 36.4, 42.6,
3.1 (2C), 43.3, 45.7, 45.8, 48.4, 55.1, 56.0, 56.1, 56.4, 56.5,
6.7, 56.8, 58.7, 65.7, 65.8, 66.0, 66.1, 95.9, 110.9, 112.2, 113.3,
14.0, 114.7 (2C), 115.5, 123.4, 123.5, 123.6, 125.9, 126.3 127.9,
29.8, 130.6, 130.7, 130.8, 132.0, 132.1, 135.1, 135.5, 136.1,
36.3, 136.6, 136.8, 138.1 (2C), 140.6, 140.7, 140.8, 142.8,
42.9, 154.6, 154.7, 155.7, 156.5, 156.7, 157.3, 157.5,
References
1
2
3
4
5
6
D. Boehme and A. G. Beck-Sickinger, J. Pept. Sci, 2015, 21,
86–200.
L. Fiume, M. Manerba and G. Di Stefano, Expert. Opin.
Drug Del., 2014, 11, 1203–1217.
1
68.8, 173.1, 173.2 (2C), 173.3, 197.6, 197.8. HRMS-ESI (m/z):
E. E. Ramsay and P. J. Dilda, Front. Pharmacol., 2014, 5,
+
[M + H] calcd for C50
H
58
N
5
O
5
, 808.4432; found, 808.4422.
1
81.
A. A. Radwan and F. K. Alanazi, Saudi Pharm. J., 2014, 22,
–16.
N-(2-((2-(4-(1-(4-Hydroxyphenyl)-2-phenylbut-1-en-1-yl)
phenoxy)ethyl)(methyl)amino)ethyl)-10-(2-((4-methoxy-1H,1′H-
3
H.-P. Gerber, F. E. Koehn and R. T. Abraham, Nat. Prod.
Rep., 2013, 30, 625–639.
C. Peters and S. Brown, Biosci. Rep., 2015, 35, e00225.
[2,2′-bipyrrol]-5-yl)methylene)-3,5-dimethyl-2H-pyrrol-4-yl)-N-
methyl-10-oxodecanamide 51c
Obtained using GP2 and 1c. Orange glass (70 mg, 84%).
7 A. M. Sochaj, K. W. Swiderska and J. Otlewski, Biotechnol.
Adv., 2015, 33, 775–784.
1
Formed as 1 : 1 mixture of E and Z isomers: H NMR (CDCl ,
3
5
(
8
(
00 MHz): δ 0.89–0.93 (m, 6H), 1.26–1.27 (m, 16H), 156–1.63
m, 8H), 2.19–2.28 (m, 10H), 2.32–2.33 (m, 4H), 2.39–2.41 (m,
H), 2.47 (quint., J = 7.4 Hz, 4H), 2.56–2.61 (m, 2H), 2.62–2.68
m, 6H), 2.73–2.76 (m, 2H), 2.83–2.87 (m, 2H), 2.89–3.01 (m,
8 M. A. Ghaz-Jahanian, F. Abbaspour-Aghdam, N. Anarjan,
A. Berenjian and H. Jafarizadeh-Malmiri, Mol. Biotechnol.,
2015, 57, 201–218.
9 C. M. Dawidczyk, C. Kim, J. H. Park, L. M. Russell,
K. H. Lee, M. G. Pomper and P. C. Searson, J. Controlled
Release, 2014, 187, 133–144.
6
3
2
6
H), 3.34–3.51 (m, 4H), 3.71 (s, 1H), 3.86–3.91 (m, 2H), 3.97 (s,
H), 4.02–4.07 (m, 2H), 6.03–6.04 (d, J = 5 Hz, 2H), 6.24 (br s,
H), 6.45–6.50 (m, 4H), 6.56–6.68 (m, 2H), 6.72–6.75 (m, 4H), 10 C. Ferrario and G. Batist, Expert Opin. Drug Discovery, 2014,
.79–6.84 (m, 6H), 6.92–7.03 (m, 2H), 7.12–7.15 (m, 14H). 9, 647–668.
C NMR (CDCl , 125 MHz): δ 12.5, 13.8, 14.4, 24.4 (2C), 25.1 11 R. Morphy and Z. Rankovic, J. Med. Chem., 2005, 48, 6523–
1
3
3
(
(
2C), 25.6, 29.1, 29.2, 29.4, 29.5 (2C), 33.0, 33.1, 33.6, 33.7, 34.1
2C), 36.4 (2C), 36.5, 42.8, 43.1 (2C), 43.4, 45.8 (2C), 48.5 (2C), 12 M. Morioka, A. Kamizono, H. Takikawa, A. Mori, H. Ueno,
6543.
5
6
1
1
1
1
1
5.1, 56.0, 56.1, 56.5, 56.6, 56.8, 56.9, 58.7, 65.5, 65.8, 65.9,
6.0, 66.1, 67.2, 96.0, 110.9, 112.2, 113.3, 114.0, 114.7 (2C),
15.4, 115.5, 123.5, 125.9, 126.1, 127.9, 129.8, 130.7, 130.8, 13 A. Fürstner, Angew. Chem., Int. Ed., 2003, 42, 3582–3603.
32.0, 132.1 (2C), 132.2, 135.1, 135.2, 135.4, 135.5, 136.1, 14 N. R. Williamson, P. C. Fineran, F. J. Leeper and
36.4, 136.6, 136.8, 138.1 (2C), 140.7, 140.8 (2C), 140.9, 142.5,
S.-i. Kadowaki, Y. Nakao, K. Kato and K. Umezawa, Bioorg.
Med. Chem., 2010, 18, 1143–1148.
G. P. Salmond, Nat. Rev. Microbiol., 2006, 4, 887–899.
42.8, 142.9 (2C), 154.6, 154.7, 155.6, 155.7, 156.5, 156.7, 15 R. D’Alessio, A. Bargiotti, O. Carlini, F. Colotta, M. Ferrari,
57.3, 157.5, 168.9, 173.4, 173.5, 173.6 (2C), 198.5 (2C).
P. Gnocchi, A. M. Isetta, N. Mongelli, P. Motta, A. Rossi,
Org. Biomol. Chem.
This journal is © The Royal Society of Chemistry 2017

View Article Online
Organic & Biomolecular Chemistry
Paper
M. Rossi, M. Tibolla and E. Vanotti, J. Med. Chem., 2000, 38 S. Rastogi, E. Marchal, I. Uddin, B. Groves, J. Colpitts,
4
3, 2557–2565.
S. A. McFarland, J. T. Davis and A. Thompson, Org. Biomol.
Chem., 2013, 11, 3834–3845.
39 J. Regourd, A. Al-Sheikh Ali and A. Thompson, J. Med.
Chem., 2007, 50, 1528–1536.
1
6 F. Alihosseini, K.-S. Ju, J. Lango, B. D. Hammock and
G. Sun, Biotechnol. Prog., 2008, 24, 742–747.
7 J.-M. Lehn, Chem. – Eur. J., 2000, 6, 2097–2102.
1
1
8 T. Nakashima, M. Kurachi, Y. Kato, K. Yamaguchi and 40 D. A. Smithen, A. M. Forrester, D. P. Corkery, G. Dellaire,
T. Oda, Microbiol. Immunol., 2005, 49, 407–415.
J. Colpitts, S. A. McFarland, J. N. Berman and
1
9 K. Papireddy, M. Smilkstein, J. X. Kelly, S. M. Salem,
A. Thompson, Org. Biomol. Chem., 2013, 11, 62–68.
M. Alhamadsheh, S. W. Haynes, G. L. Challis and 41 M. I. Uddin, S. Thirumalairajan, S. M. Crawford,
K. A. Reynolds, J. Med. Chem., 2011, 54, 5296–5306. T. S. Cameron and A. Thompson, Synlett, 2010, 2561–2564.
0 B. Montaner and R. Pérez-Tomás, Life Sci., 2001, 68, 2025– 42 P. M. Levine, M. J. Garabedian and K. Kirshenbaum,
036. J. Med. Chem., 2014, 57, 8224–8237.
1 R. Pérez-Tomás, B. Montaner, E. Llagostera and V. Soto- 43 J. Provencher-Mandeville, C. Debnath, S. K. Mandal,
2
2
2
2
Cerrato, Biochem. Pharmacol., 2003, 66, 1447–1452.
V. Leblanc, S. Parent, É. Asselin and G. Bérubé, Steroids,
2011, 76, 94–103.
2 M. S. Melvin, J. T. Tomlinson, G. Park, C. S. Day,
G. R. Saluta, G. L. Kucera and R. A. Manderville, Chem. Res. 44 R. Schobert, G. Bernhardt, B. Biersack, S. Bollwein,
Toxicol., 2002, 15, 734–741.
M. Fallahi, A. Grotemeier and G. L. Hammond,
2
2
3 S. Ohkuma, T. Sato, M. Okamoto, H. Matsuya, K. Arai,
T. Kataoka, K. Nagai and H. H. Wasserman, Biochem. J., 45 C. Van Themsche, S. Parent, V. Leblanc, C. Descôteaux,
ChemMedChem, 2007, 2, 333–342.
1
998, 334, 731–741.
A.-M. Simard, G. Bérubé and E. Asselin, Endocr. – Relat.
Cancer, 2009, 16, 1185–1195.
4 T. Sato, H. Konno, Y. Tanaka, T. Kataoka, K. Nagai,
H. H. Wasserman and S. Ohkuma, J. Biol. Chem., 1998, 273, 46 V. C. Jordan, J. Med. Chem., 2003, 46, 1081–1111.
1455–21462. 47 V. C. Jordan, J. Med. Chem., 2003, 46, 883–908.
5 J. L. Seganish and J. T. Davis, Chem. Commun., 2005, 5781– 48 K. Cyrus, M. Wehenkel, E.-Y. Choi, H. Lee, H. Swanson and
783. K.-B. Kim, ChemMedChem, 2010, 5, 979–985.
6 M. S. Melvin, J. T. Tomlinson, G. R. Saluta, G. L. Kucera, 49 D. Spera, G. Cabrera, R. Fiaschi, K. E. Carlson,
2
2
2
5
N. Lindquist and R. A. Manderville, J. Am. Chem. Soc., 2000,
22, 6333–6334.
J. A. Katzenellenbogen and E. Napolitano, Bioorg. Med.
Chem., 2004, 12, 4393–4401.
1
2
7 G. Park, J. T. Tomlinson, M. S. Melvin, M. W. Wright, 50 J. P. Trebley, E. L. Rickert, P. T. Reyes and
C. S. Day and R. A. Manderville, Org. Lett., 2003, 5, 113–116.
8 R. I. S. Diaz, J. Regourd, P. V. Santacroce, J. T. Davis,
R. V. Weatherman, Ernst Schering Res. Found. Workshop,
2006, 58, 75–87.
2
D. L. Jakeman and A. Thompson, Chem. Commun., 2007, 51 D. C. Labaree, J.-x. Zhang, H. A. Harris, C. O’Connor,
2
701–2703.
T. Y. Reynolds and R. B. Hochberg, J. Med. Chem., 2003, 46,
1886–1904.
52 J.-x. Zhang, D. C. Labaree and R. B. Hochberg, J. Med.
Chem., 2005, 48, 1428–1447.
2
3
9 A. Fürstner, K. Reinecke, H. Prinz and H. Waldmann,
ChemBioChem, 2004, 5, 1575–1579.
0 B. Montaner, W. Castillo-Avila, M. Martinell, R. Oellinger,
J. Aymami, E. Giralt and R. Perez-Tomas, Toxicol. Sci., 2005, 53 R. Tedesco, R. Fiaschi and E. Napolitano, J. Org. Chem.,
5, 870–879. 1995, 60, 5316–5318.
1 W. R. Hearn, M. K. Elson, R. H. Williams and J. Medina- 54 S. D. Lepore and Y. He, J. Org. Chem., 2003, 68, 8261–8263.
8
3
3
3
Castro, J. Org. Chem., 1970, 35, 142–146.
2 S. M. Crawford, A. Al-Sheikh Ali, T. S. Cameron and
A. Thompson, Inorg. Chem., 2011, 50, 8207–8213.
55 S. M. Goldup, D. A. Leigh, T. Long, P. R. McGonigal,
M. D. Symes and J. Wu, J. Am. Chem. Soc., 2009, 131,
15924–15929.
3 C. L. A. Hawco, E. Marchal, M. I. Uddin, A. E. G. Baker, 56 T. W. Greene and P. G. M. Wuts, in Protective Groups in
D. P. Corkery, G. Dellaire and A. Thompson, Bioorg. Med.
Chem., 2013, 21, 5995–6002.
Organic Synthesis, John Wiley
pp. 17–245.
&
Sons, Inc., 2002,
3
4 E. Marchal, S. Rastogi, A. Thompson and J. T. Davis, Org. 57 D. L. Reger, J. D. Elgin, M. D. Smith, F. Grandjean,
Biomol. Chem., 2014, 12, 7515–7522.
L. Rebbouh and G. J. Long, Polyhedron, 2006, 25, 2616–
3
5 E. Marchal, D. A. Smithen, I. M. Uddin, A. W. Robertson,
2622.
D. L. Jakeman, V. Mollard, C. D. Goodman, 58 M. Shibasaki, Y. Ishida and N. Okabe, Tetrahedron Lett.,
K. S. MacDougall, S. A. McFarland, G. I. McFadden and
A. Thompson, Org. Biomol. Chem., 2014, 12, 4132–4142.
6 E. Marchal, M. I. Uddin, C. L. A. Hawco and A. Thompson,
Can. J. Chem., 2015, 93, 526–535.
1985, 26, 2217–2220.
59 X.-R. Jiang, J. Walter Sowell and B. T. Zhu, Steroids, 2006,
71, 334–342.
60 J. Mulzer and B. Schöllhorn, Angew. Chem., Int. Ed. Engl.,
1990, 29, 431–432.
3
3
7 E. Marchal, M. I. Uddin, D. A. Smithen, L. A. Hawco,
M. Lanteigne, D. P. Overy, R. G. Kerr and A. Thompson, 61 K. K. Olgivie and D. W. Entwistle, Carbohydr. Res., 1981, 89,
RSC Adv., 2013, 3, 22967–22971. 203–210.
This journal is © The Royal Society of Chemistry 2017
Org. Biomol. Chem.

View Article Online
Paper
Organic & Biomolecular Chemistry
6
6
6
6
6
6
6
6
7
7
7
7
7
2 A. T. Placzek, J. L. Hougland and R. A. Gibbs, Org. Lett.,
and J. A. Katzenellenbogen, J. Steroid Biochem., 2000, 74,
279–285.
2
012, 14, 4038–4041.
3 O. Norberg, L. Deng, T. Aastrup, M. Yan and O. Ramström, 77 J. P. Trebley, E. L. Rickert, P. T. Reyes and
Anal. Chem., 2010, 83, 1000–1007.
4 L. Duc, J. F. McGarrity, T. Meul and A. Warm, Synthesis,
R. V. Weatherman, in Chem. Genomics, ed. S. Jaroch and H.
Weinmann, Springer, Berlin Heidelberg, 2006, vol. 58, ch.
6, pp. 75–87.
1
992, 391–394.
5 C. Schmuck, D. Rupprecht, C. Urban and N. Walden, 78 https://dtp.cancer.gov/discovery_development/nci-60/meth-
Synthesis, 2006, 89–96. odology.htm.
6 M. Meldal and C. W. Tornøe, Chem. Rev., 2008, 108, 2952– 79 J. M. Lamar, P. Stern, H. Liu, J. W. Schindler, Z. G. Jiang
3
015.
and R. O. Hynes, Proc. Natl. Acad. Sci. U. S. A., 2012, 109,
E2441–E2450.
80 J. Feng, J. Gou, J. Jia, T. Yi, T. Cui and Z. Li, OncoTargets
Ther., 2016, 29, 5371–5381.
81 C. Wang, X. Zhu, W. Feng, Y. Yu, K. Jeong, W. Guo, Y. Lu
and G. B. Mills, Am. J. Cancer Res., 2016, 6, 27–37.
82 W. Pan, Q. Wang, Y. Zhang, N. Zhang, J. Qin, W. Li,
J. Wang, F. Wu, L. Cao and G. Xu, Cell. Physiol. Biochem.,
2016, 39, 481–490.
7 J. Kühhorn, A. Götz, H. Hübner, D. Thompson, J. Whistler
and P. Gmeiner, J. Med. Chem., 2011, 54, 7911–7919.
8 Q. Wang, T. R. Chan, R. Hilgraf, V. V. Fokin, K. B. Sharpless
and M. G. Finn, J. Am. Chem. Soc., 2003, 125, 3192–3193.
9 J. Notni and H.-J. Wester, Chem. – Eur. J., 2016, 22, 11500–
1
1508.
0 T. Kowada, H. Maeda and K. Kikuchi, Chem. Soc. Rev.,
015, 44, 4953–4972.
2
1 N. Boens, V. Leen and W. Dehaen, Chem. Soc. Rev., 2012, 83 K. Brodowska, A. Al-Moujahed, A. Marmalidou, M. Meyer
4
1, 1130–1172.
2 M. Benstead, G. H. Mehl and R. W. Boyle, Tetrahedron,
011, 67, 3573–3601.
Zu Horste, J. Cichy, J. W. Miller, E. Gragoudas and
D. G. Vavvas, Exp. Eye Res., 2014, 124, 67–73.
84 W. Chen, Z. Cao, C. Krishnan and N. Panjwani, Biochem.
Biophys. Res. Commun., 2015, 466, 221–225.
85 Y. Liu-Chittenden, B. Huang, J. S. Shim, Q. Chen, S. J. Lee,
R. A. Anders, J. O. Liu and D. Pan, Genes Dev., 2012, 26,
1300–1305.
2
3 G. Ulrich, R. Ziessel and A. Harriman, Angew. Chem., Int.
Ed., 2008, 47, 1184–1201.
4 R. Ziessel, G. Ulrich and A. Harriman, New J. Chem., 2007,
3
1, 496–501.
7
7
5 A. Loudet and K. Burgess, Chem. Rev., 2007, 107, 4891–4932. 86 R. J. Detz, S. A. Heras, R. de Gelder, P. W. N. M. van
6 B. S. Katzenellenbogen, I. Choi, R. Delage-Mourroux,
T. R. Ediger, P. G. V. Martini, M. Montano, J. Sun, K. Weis
Leeuwen, H. Hiemstra, J. N. H. Reek and J. H. van
Maarseveen, Org. Lett., 2006, 8, 3227–3230.
Org. Biomol. Chem.
This journal is © The Royal Society of Chemistry 2017