Synthesis and structure-activity relationship studies of parthenolide derivatives as potential anti-triple negative breast cancer agents

Article abstract of DOI:10.1016/j.ejmech.2019.01.058

Triple-negative breast cancer (TNBC) is the most aggressive cancers with a high recurrence rate and rapidly acquired drug resistance among various breast cancer subtypes. There is no specific drug for treatment of TNBC. Discovery of therapeutic agents with unique modes of actions is urgently needed. In this study, a series of seventy parthenolide derivatives was designed, synthesized, and evaluated for their anti-TNBC activities. Compound 7d exhibited the most potent activity against different breast cancer cells with IC₅₀ values ranging from 0.20 μM to 0.27 μM, which demonstrated 11.6- to 18.6-fold improvement comparing to that of the parent compound parthenolide with IC₅₀ values of 2.68–4.63 μM. It is worth to note that 7d was more active than the positive control drug ADR. Moreover, compound 7d could induce apoptosis of SUM-159 cells through mitochondria pathway and cause G1 phase arrest of SUM-159 cells. These findings indicate that compound 7d deserves further studies as a lead compound for ultimate discovery of effective anti-TNBC drug.

Full text of DOI:10.1016/j.ejmech.2019.01.058

Accepted Manuscript
Synthesis and structure-activity relationship studies of parthenolide derivatives as
potential anti-triple negative breast cancer agents
Weizhi Ge, Xin Hao, Fangzhi Han, Zhongquan Liu, Tianpeng Wang, Mengmeng
Wang, Ning Chen, Yahui Ding, Yue Chen, Quan Zhang
PII:
S0223-5234(19)30079-0
DOI:
https://doi.org/10.1016/j.ejmech.2019.01.058
EJMECH 11065
Reference:
To appear in: European Journal of Medicinal Chemistry
Received Date: 6 November 2018
Revised Date: 23 January 2019
Accepted Date: 23 January 2019
Please cite this article as: W. Ge, X. Hao, F. Han, Z. Liu, T. Wang, M. Wang, N. Chen, Y. Ding, Y. Chen,
Q. Zhang, Synthesis and structure-activity relationship studies of parthenolide derivatives as potential
anti-triple negative breast cancer agents, European Journal of Medicinal Chemistry (2019), doi: https://
doi.org/10.1016/j.ejmech.2019.01.058.
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ACCEPTED MANUSCRIPT
Graphical abstract
Synthesis
and
Structure-Activity
Relationship Studies of Parthenolide
Derivatives as Potential anti-Triple
Negative Breast Cancer Agents
†
†
†
†
†
‡
Weizhi Ge, Xin Hao, Fangzhi Han, Zhongquan Liu, Tianpeng Wang, Mengmeng Wang,
‡
†,
†,
†,
Ning Chen, Yahui Ding, * Yue Chen * and Quan Zhang *
MeO
O
O
1
. Kg scale PTL in hand
MeO
11.6- to 18.6-fold activity compared to PTL
Cause G1 phase arrest of cell cycle
2. A library of 70 derivatives
3. Anti-TNBC screening
4. SAR study
O
O
Induce mitochondria-mediated apoptosis
O
O
O
O
PTL
7d

ACCEPTED MANUSCRIPT
Synthesis and Structure-Activity Relationship
Studies of Parthenolide Derivatives as Potential
anti-Triple Negative Breast Cancer Agents
a
a
a
a
a
b
Weizhi Ge, Xin Hao, Fangzhi Han, Zhongquan Liu, Tianpeng Wang, Mengmeng Wang,
b
a,
a,
a,
Ning Chen , Yahui Ding, * Yue Chen * and Quan Zhang *
a
State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy and Tianjin Key
Laboratory of Molecular Drug Research, Nankai University, Haihe Education Park, 38 Tongyan
Road, Tianjin 300353, People’s Republic of China
b
Accendatech Company, Ltd., Tianjin 300384, People's Republic of China
Corresponding Authors
Y.D.: E-mail: 017095@nankai.edu.cn; Tel./Fax: +86-022-85358387
Y.C.: E-mail: yuechen@nankai.edu.cn; Tel./Fax: +86-022-85358387
Q.Z.: E-mail: zhangquan@nankai.edu.cn or zhangquan612@163.com; Tel./Fax: +86-022-
8
5358387
1

ACCEPTED MANUSCRIPT
ABSTRACT
Triple-negative breast cancer (TNBC) is the most aggressive cancers with a high recurrence rate
and rapidly acquired drug resistance among various breast cancer subtypes. There is no specific
drug for treatment of TNBC. Discovery of therapeutic agents with unique modes of actions is
urgently needed. In this study, a series of seventy parthenolide derivatives was designed,
synthesized, and evaluated for their anti-TNBC activities. Compound 7d exhibited the most
potent activity against different breast cancer cells with IC50 values ranging from 0.20 µM to
0
.27 µM, which demonstrated 11.6- to 18.6-fold improvement comparing to that of the parent
compound parthenolide with IC50 values of 2.68–4.63 µM. It is worth to note that 7d was more
active than the positive control drug ADR. Moreover, compound 7d could induce apoptosis of
SUM-159 cells through mitochondria pathway and cause G1 phase arrest of SUM-159 cells.
These findings indicate that compound 7d deserves further studies as a lead compound for
ultimate discovery of effective anti-TNBC drug.
KEYWORDS
Parthenolide; Structure-activity relationship; Triple negative breast cancer; Apoptosis; Cell
cycle
2

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1
. INTRODUCTION
Breast cancer is the most common cancer and the second leading cause of cancer-related
mortality among women in the world [1-3]. Every year, an estimated 1 to 1.3 million breast
cancer cases are diagnosed worldwide [4]. Triple-negative breast cancer (TNBC) is characterized
by lack of expression of human epidermal growth factor receptor 2 (HER-2), estrogen receptor
(
ER), and progesterone receptor, which accounts for approximately 15–20 % of breast cancer
cases, and more frequent in African-American younger women and BRCA1 mutation carriers.
5-7]. TNBC is the most aggressive cancers with a high recurrence rate and rapidly acquired drug
[
resistance among various breast cancer subtypes [8-10]. TNBC could increase lymphocytic
infitration, and have large tumor size. TNBCs are associated with a 4-fold increase in the risk of
distant metastases [11]. TNBCs metastasize to the lungs and central nervous system more
frequently than non-TNBCs, which most commonly metastasize to the bone [12, 13]. This
aggressive metastatic behavior contributes to the overall shortened survival of patients with
TNBC compared with non-TNBC. Because of the lack of appropriate targets, TNBC patients
couldn’t benefit from molecularly targeted therapy, such as endocrine therapy or trastuzumab.
Cytotoxic chemotherapy (i.e., taxanes, anthracyclines, capecitabine, ixabepilone) is the only
standard of care therapeutic choice for patients presenting with metastatic TNBC [14-16].
Although these patients respond to chemotherapeutic agents such as taxanes and anthracyclines
better than other subtypes of breast cancer, prognosis remains poor. The reason is that although
the initial chemotherapy results are significant, it is limited by dose-related toxic factors and
acquired chemoresistance, it is difficult to guarantee the chemotherapy cycle, which leads to
recurrence finally [17, 18]. Therefore, discovering therapeutic agents with unique modes of
actions is urgently needed to overcome current challenges in TNBC treatment.
3

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Sesquiterpenes lactones (SLs) have attracted extensive attention because of their potent
bioactivity, such as anti-cancer, anti-inflammatory and anti-malaria [19-21]. Parthenolide (1,
PTL, Figure 1), a prominent germacrane type SL, showed promising anti-cancer property.
Nevertheless, PTL has some disadvantages, such as poor oral bioavailability, lack of stability
under chemical and physiological conditions and poor water solubility [22-25]. DMAPT
(dimethylaminoparthenolide), a prodrug of PTL, effectively increased the water solubility and
oral bioavailability, which has advanced into a phase I clinical trial for treatment of acute
myeloid leukemia (AML) [21]. Recently, we developed the other PTL derivative, ACT001 [23],
to be in clinical trial in Australia and China for treatment of glioblastoma [26].
Cinnamic acid (CA) is a naturally occurring aromatic fatty acid composed of a phenyl ring
substituted with an acrylic acid group, which has a long history of being used as a plant
flavourings and spices [27-28] Cinnamic acid (CA) and cinnamic acid derivatives (CADs) were
.
found abundantly in many plants and food, exhibited a broad spectrum of biological activities,
including anticancer, antioxidant, antimicrobial, antiviral antiinflmmatory, hepatoprotective and
hypolipidemic [29-32]. CADs possesses an α,β-unsaturated carbonyl, which can be considered as
a Michael acceptor, an active structural unit often appeared in the design of drugs [33-35]. CA
scafflds are present in several registered drugs, such as Panobinostat (antitumor drug) and
cinanserin and tranilast (antiallergic drugs) [36-38]. Anticancer potential of CADs has been
known for more than a century [39]. The antitumor activities of various cinnamic acid derivatives
has attracted the interest of many research teams. Particularly, cinnamic acid ester derivatives
can significantly increase antitumor activity [40-43]. There are many studies reported that it
could generate ROS to induce apoptosis [44-46].
4

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In this study, with PTL as the starting point, we developed a series of PTL derivatives,
investigated their biological activities as potential anti-TNBC agents, and discussed the
structure−activity relationship (SAR), which led to the discovery of the most potent compound
7
d. The preliminary mechanism of 7d was also investigated.
2
. RESULTS AND DISCUSSION
2
.1 Chemistry
It was reported that the starting material parthenolide was obtained from feverfew
(Tanacetum parthenium) in yield of only 0.14–0.74% [47]. We discovered that parthenolide
could be readily crystallized in approximately 5% yield from the extract of root bark of
Magnolia delavayi without chromatography. With abundant PTL (kilogram scale) in hand, we
started the synthesis of PTL derivatives. PTL was converted to melampomagnolide B (MMB, 2)
following the procedure reported by our group [48]. The primary hydroxyl of MMB would be
efficiently modified to improve its potency and to study the SAR. As described in Scheme 1,
MMB conjugated with cinnamic acid or difference patterns of mono-substituted cinnamic acids
to generate derivatives 4a–4x, which could be evaluated for their anti-TNBC activity to explore
the influence of different substituents of the benzene ring on their anti-TNBC activity. When
phenolic hydroxyl groups of cinnamic acid derivatives were used, the yield of the esterification
reaction was very low under the generally used condition (EDCI, DMAP, and TEA in CH Cl ).
2
2
We proposed that phenolic hydroxyl group was more reactive than the primary hydroxyl of
MMB under used condition (EDCI, DMAP, and TEA in CH Cl ), which led to self-esterification
2
2
for substituted cinnamic acids containing phenolic hydroxyl groups. Finally, we utilized the
Mitsunobu reaction, DIAD and PPh
3
in THF, to prepare 5a and 5b in yields of 76% and 55%,
5

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respectively. In order to further investigate the effects of phenyl group in cinnamic acid, we
designed the derivatives with replacement of the phenyl group in cinnamic acid with heterocyclic
rings (6a–6e), naphthalene ring (6f), or benzodioxole ring (6g). As shown in Scheme 2,
compounds 6a, 6b, 6f and 6g was readily prepared in the presence of EDCI, DMAP, and TEA in
high yields of 82%–95%. However, for the pyridinylacrylic acids, no reaction was observed
under EDCI, DMAP, and TEA condition, which would attribute to the low reactivity of the ester
intermediate. The pyridinylacrylic acids were firstly converted to the corresponding acyl chloride
and then reacted with MMB to yield compounds 6c–6e in yields of 66%–77%. MMB was
reacted with commercial available di-methoxyl, tri-methoxyl or di-halo substituted cinnamic
acids to give derivatives 7a–7m (Scheme 3).
To investigate the effect of 17-substitutents of cinnamyl moiety on the anti-TNBC activity,
derivatives 10a–10i, 12a–12c and 14 were designed, as shown in Scheme 4. We used 8a as the
starting material by Knoevenagel reaction to prepare a series of 17-substitued cinnamic acids 9a–
9
1
i, 11a–11c and 13, followed by direct esterification with MMB to generate derivatives 10a–10i,
2a–12c and 14.
Preliminary study indicated that compounds 7c and 7d showed high activity against MDA-
MB-231 cells. Both of two derivatives have two α, β-unsaturated ester moieties. In order to
explore the effects of these two α, β-unsaturated ester moieties on their anti-TNBC activities, we
designed compound 16 with trim of the double bond of cinnamyl moiety, compounds 20a and
2
0b with reduction of the double bonds of γ-butyrolactone moiety, and compounds 21a and 21b
with reduction of the double bonds of cinnamyl moiety (Scheme 5). Compound 16 was
synthesized by esterification of MMB and 2, 6-dimethoxybenzoic acid in 83% yield. Reduction
of MMB with sodium borohydride in an ice-water bath generated alcohol 15. Aldehydes 8a and
6

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8
b were through Knoevenagel reaction to provide the corresponding α, β-unsaturated acids 17a
and 17b. Reaction of alcohol 15 with α, β-unsaturated acids 17a and 17b afforded esters 20a and
0b, respectively. Reduction of the α, β-unsaturated acids 17a and 17b with H , Pd/C afforded
2
2
acids 18a and 18b, which were subsequently coupled with MMB to produce esters 21a and 21b,
respectively. To study the effect of ten-membered skeleton of PTL moiety, compounds 19a and
1
9b were also synthesized.
The details of the synthetic procedures and structural characterizations are described in the
Experimental Section. The assignment of the NMR spectra was also provided in Experimental
Section. The purity of all PTL derivatives was confirmed to be ≥95% by HPLC.
2
.2 The antiproliferative activity of parthenolide derivatives against breast cancer cells
The in vitro antiproliferative efficacy of the parthenolide derivatives 3, 4a–4x and 5a–5b
was determined by the MTT assay using human breast cancer cell line MDA-MB-231 and
compared with the reference compounds, PTL (1) and MMB (2). In addition, adriamycin (ADR),
the clinically used drug, was introduced as a positive control.
As shown in Table 1, the natural product PTL (1, IC50 = 3.48 µM) and MMB (2, IC50 = 5.59
µM) exhibited moderate activity against the MDA-MB-231 cells. Generally, all the tested
twenty-seven derivatives 3, 4a–4x and 5a–5b in Table 1 were more potent than PTL and MMB
against the MDA-MB-231 cells, which indicated that the introduction of cinnamyl or substituted
cinnamyl moiety was beneficial to anti-TNBC activity. Compound 3 (IC = 1.35 µM) with
50
introduction of cinnamyl moiety exhibited two-fold anti-TNBC activity compared to PTL (IC =
50
3
.48 µM). Different patterns of substituents were induced to the ortho-position of the benzene
ring provided compounds 4a–4g. Among them, three compounds 4a, 4f, 4g showed high activity
7

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with IC50 values lower than 1 µM. Introduction of halogen atoms (4b–4d) or methyl group (4e),
with IC values ranging from 1.33 µM to 1.80 µM, slightly increased the anti-TNBC activity
5
0
compared with PTL. Compound 4a with the strong electron-withdrawing group trifluoromethyl
exhibited further improved activity (IC50 = 0.74 µM). When the electron-donating group
methoxy group (4f, IC = 0.46 µM) and ethoxyl group (4g, IC = 0.34 µM) were introduced, the
5
0
50
activity was further enhanced. Especially, compound 4g was about 10-fold more efficacious than
PTL for MDA-MB-231 cells. The above results indicate that the introduction of an electron-
donating group at the ortho-position of the benzene ring is beneficial to the antiproliferative
potency. Compounds 4h–4m, introducing different substituents at the meta-position of the
phenyl ring, exhibited comparable or decreased activity comparing with their ortho-position
counterparts 4a–4f, respectively. The anti-TNBC activities of compounds 4n–5a, which
introduced different substituents at the para-position of the phenyl ring, were slightly enhanced
in comparison with PTL. Compound 5b showed moderate activity with IC value of 2.01 µM.
50
To investigate the effect of phenyl group in compound 3, we synthesized compounds 6a–6g
with replacement of phenyl group with different aromatic rings. Their activities were shown in
Table 2. These compounds showed comparable or slightly decreased activity compared with
compound 3.
Based on the above preliminary results, we decided to further explore the influence of
different substituents on phenyl ring of compound 3. Compounds 7a–7m were synthesized and
evaluated against MDA-MB-231 cells, and the results are shown in Table 3. Among subseries of
7
a–7f with dimethoylphenyl moiety, compounds 7b, 7c and 7d showed improved activity
compared to compound 3. The activity was in the order of 2,6 (7d) > 2,5 (7c) > 2,4 (7b) > 2,3
(7a) > 3,4 (7e) > 3,5 (7f). Importantly, compounds 7c and 7d exhibited significantly inhibitory
8

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activity against the MDA-MB-231 cells with IC50 values of 0.26 µM and 0.25 µM, respectively,
which was approximately 14-fold and 22-fold more potent than PTL (IC = 3.48 µM) and MMB
5
0
(
IC = 5.596 µM), respectively. It is worth to note that compounds 7c and 7d were more active
50
than the positive control drug ADR (IC50 = 0.8 µM). When three methoxy groups were
introduced (compounds 7g–7j), except for 7g (IC = 1.77 µM), the antiproliferative activity of
50
7
h–7j was slightly improved with IC values ranging from 0.95 µM to 1.09 µM in comparison
50
with compound 3 (IC50 = 1.35 µM). Taking account that compound 7d with two methoxy groups
at 2,6-positions of benzene ring, compound 7k–7m, replacing of two methoxy groups with 2, 6-
dihalogen, were also synthesized and evaluated for their anti-TNBC activity. However, the
replacements led to decreased activities (IC50 = 1.50–1.59 µM) compared to 7d (IC = 0.25
50
µM).
After investigating the effect of substituents on the benzene ring of cinnamyl moiety, we
focused our attention on the double bond of cinnamyl moiety. Compound 7c was selected as the
basic skeleton. We designed to introduce different patterns of substituents on 17-position of the
cinnamyl moiety, such as phenyl, substituted phenyl, alkyl and cyano, i.e. compounds 10a–10i,
1
2a–12c and 14. Their suppressant properties on MDA-MB-231 cells were evaluated, and the
results are shown in Table 4. The introduction of a phenyl group (10a) or substituted phenyl
group (10b–10i) seriously reduced anti-TNBC activity (IC50 = 1.87 µM–2.95 µM) comparing
with their parent compound 7c (IC50 = 0.26 µM). For compounds 12a–12c, the results suggested
that the introduction of alkyl chains on the double bond resulted in a decrease in activity, and as
the increase of chain length, activity decreased significantly. Compound 14, with introduction of
an electron-withdrawing cyano group into the double bond, also showed a 9-fold decrease in
9

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comparison with 7c. The above results demonstrated that 17-position of the cinnamyl moiety
cannot accommodate diverse modification.
Finally, to investigate the contribution of each α, β-unsaturated ester bonds and further
study the SAR, we designed compounds 16, 20a–b and 21a–b with elimination of one of double
bond. To indicate the importance of 10-membered ring, esters 19a–b were also synthesized and
evaluated for their anti-cancer activity. Compound 16, with trim of the double bond of cinnamyl
moiety in compound 7d, reduced by 14.2 folds compared to 7d (16: IC = 3.55 µM vs 7d: IC
50
5
0
=
0.25 µM), which demonstrated the significance of the double bond for its activity. When the
double bond of cinnamyl moeity was reduced, i.e. compounds 21a (IC = 1.88 µM) and 21b
5
0
(
IC50 = 2.30 µM), their activities were also significantly reduced in comparison with 7c and 7d,
respectively, but slightly stronger than PTL (IC50 = 3.48 µM). Similarly, when the double bond
of the γ-butyrolactone ring of PTL was reduced, i.e. compounds 20a (IC = 6.80 µM) and 20b
5
0
(
IC = 7.6 µM), their potency was greatly decreased compared to 7d. It is worth to note that 21a
50
and 21b were more potent than 20a and 20b, respectively, which prompted us to propose that α-
methylene-γ-butyrolactone fragment is more significant than the cinnamyl moiety. Esters 19a
(
IC > 50 µM) and 19b (IC > 20 µM) lost anti-TNBC activity. Moreover, as shown in Figure 2,
50 50
compounds 17b (IC50 > 50 µM) and MMB (IC50 = 5.59 µM) or combination of 17b and MMB
1:1) (IC50 = 3.92 µM) were less potent than 7d (IC50 = 0.25 µM). These results suggest that the
(
anti-TNBC activity of 7d may be attributed to the synergic effects of MMB part and cinnamyl
moiety.
Compounds 4a, 4f, 4g, 4h, 7b–7d and 7j, exhibiting high activity against MDA-MB-231
cells lower than 1 µM ranging from 0.25 µM to 0.95 µM, were selected to further characterize
their anti-breast cancer activity. These compounds were evaluated against a panel of three human
10

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breast cancer cell lines, including SUM-159, MCF-7, Bcap-37, and a mouse breast cancer cell
line 4T1. As shown in Table 6, compound 7d exhibited the most potent activity against breast
cancer cells with IC values ranging from 0.20 µM to 0.27 µM, which demonstrated 11.6- to
5
0
1
8.6-fold improvement comparing to that of the parent compound PTL.
The most potent compound 7d was further evaluated for its toxicity against normal 3T3
cells (mouse embryonic fibroblast cell line). As shown in Table 7, 7d had selective
cytotoxicity against breast cancer cells (IC = 0.22 µM) being compared with 3T3 cells (IC =
5
0
50
8
.13 µM) with therapeutic index (TI) value of 36.9. In contrast, the clinically used drug ADR
showed toxicity against 3T3 cells with IC value of 0.36 µM, which led to low therapeutic index
5
0
value of 0.45.
2
.3 Cell cycle effect of compound 7d
To further analyze the effect of compound 7d in cell proliferation, cell cycle distribution
was detected by flow cytometry. From the result of Figure 3, S phase and G2/M phase were
strongly decreased after the treatment of compound 7d for 48 hours, while G1 phase was
significantly increased with 7d treatment compared with control group. As shown in Figure 4,
the cell cycle related proteins including CHK2, p-CHK2, CHK1, p-CHK1 and p-cdc2 were down
regulated, whereas the cell cycle inhibitor P27 were up-regulated after 7d treatment for 48 hours.
2
.4 Compound 7d induced apoptosis through mitochondria-mediated pathway
In order to analyze the effect of compound 7d, the cell apoptosis assay was performed by
Annexin V/PI staining. The percentage of apoptosis cells was the sum of early apoptosis
+
-
-
-
(
annexin V /PI ) and late apoptosis (annexin V /PI ). As shown in Figure 5, the percentage of cell
11

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apoptosis was 3.1±1.0, 2.9±1.0 and 26.0±7.4 with the treatment of compound 7d at the
concentration of 0, 0.2 µM and 0.5 µM respectively. Moreover, compound 7d exhibited
significant stronger effect on induction of cell apoptosis compared with that of PTL (Figure 5). It
was reported that mitochondria-mediated apoptosis played important roles in anti-cancer drug
discovery. Therefore, we wondered that whether compound 7d induced cell apoptosis by
mitochondria. As shown in Figure 6, the relative levels of apoptotic protein Bax and Bim was
dramatically increased with a dose-dependent manner. Bax and Bim are important mitochondrial
protein which regulated the release of cytochrome C. Moreover, compound 7d induced the
cytochrome C release and the cleavage of caspase 9 to induce cell apoptosis (Figure 6). These
results above suggested that compound 7d induced mitochondria-mediated apoptosis by the
regulation of the proteins on the mitochondria.
2
.5 Reaction of Compound 7d, 20b and 21b with GSH
Covalent drugs can possess advantages over traditional non-covalent inhibitors, such as
exceptionally high efficiency, longer duration of action [49]. Thirty-nine covalent drugs have
been approved by the U.S. FDA from 1982−2009 [50]. The GSH conjugation assay was utilized
for determination of intrinsic reactivity of electrophilic warhead. The reactivity of GSH with the
covalent drugs was assessed to correlate the intrinsic reactivities of the covalent inhibitors with
the biologically relevant covalent binding [51-53]. To determine the experimental GSH reaction
rates of PTL derivatives, compounds 7d, 20b and 21b were incubated with 2.5–3 equiv of GSH
in 0.5 mL of DMSO-d6 and 0.05 mL of sodium phosphate deuterium oxide buffer (pH 7.4) at
1
3
7 °C. The reaction mixture was run H NMR at different points (Figure 7). The results indicated
that the reactivity of the covalent warhead α-methylene-γ-butyrolactone in 7d is much more
active than the enone in cinnamyl moiety. Additionally, the adduct product 25 was also validated
12

ACCEPTED MANUSCRIPT
by HRMS analysis. Under the same conditions, 21b could reacted with GSH (Figure 8), and no
reaction was observed for compound 20b (Figure 9).
3
. CONCLUSIONS
TNBC is the most aggressive cancers among various breast cancer subtypes. It is still a
great challenge in clinical treatment. Therefore, discovery of potential novel agents for treatment
of TNBC is still urgently needed. We designed, synthesized, and identified a series of
parthenolide derivatives as potential anti-TNBC agents, especially compound 7d exhibited IC50
values ranging from 0.20 µM to 0.27 µM, which was 11.6- to 18.6-fold more potent than that of
the parent compound PTL with IC values of 2.68 µM–4.63 µM for a panel of five different
5
0
breast cancer cells. Further characterization indicated that compound 7d could induce apoptosis
of SUM-159 cells through mitochondria pathway and cause G1 phase arrest of SUM-159 cells.
These findings indicate that compound 7d deserves further studies as a lead compound for
ultimate discovery of effective anti-TNBC drug.
4
. EXPERIMENTAL SECTION
4
.1 General Chemistry
Unless otherwise mentioned, all reactions were carried out under a nitrogen atmosphere
with dry solvents under anhydrous conditions. The used solvents were purified and dried
according to common procedures. Reactions were monitored by thin-layer chromatography
carried out on 0.25 mm Tsingdao silica gel plates (60F-254). Visualization was achieved using
UV light, phosphomolybdic acid in ethanol or potassium permanganate in water, each followed
by heating. Tsingdao silica gel (60, particle size 0.040–0.063 mm) was used for flash column
13

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chromatography. Reagents were purchased at the highest commercial quality and used without
further purification, unless otherwise stated. NMR spectra were recorded with a Bruker 400 MHz
1
13
(
H: 400 MHz, C: 100 MHz) spectrometer and referenced to the solvent peak for CDCl3,
CD OD and DMSO-d . Data are reported as follows: chemical shift, multiplicity (s = singlet, d =
3
6
doublet, t = triplet, q = quartet, br. = broad, m = multiplet), coupling constants and integration.
The purity of the final compounds was determined to be ≥ 95% by means of Ultimate 3000
analytical high performance liquid chromatography (HPLC) with an C18 column (4.6 × 150
mm, 5 µm, Thermofisher) eluted at 1 mL/min with Milli-Q water and CH CN. HRMS (ESI)
3
spectra were recorded with a VG ZAB-HS chromatography-mass spectrometer.
4
.1.1 Synthesis of melampomagnolide B (2)
A solution of 1 (1.0 g, 4.3 mmol) in dichloromethane (20 mL) was treated with SeO (324
2
mg, 2.4 mmol) and predried t-BuOOH (70 % in H O, 1.48 mL, 10.8 mmol) over Na SO . The
2
2
4
mixture was stirred overnight at room temperature. The reaction mixture was diluted with
dichloromethane (20 mL), and the organic layer was washed with saturated aq Na and
brine and dried over anhydrous Na SO . The solvent was removed under vacuum to get the crude,
2 2 3
S O
2
4
which was purified by column chromatography [PE:EA = 2:1 to 1:2] to give compound 2 (810
1
mg, 72%) as a white solid, H NMR (400 MHz, CDCl ) δ 6.15 (d, J = 3.5 Hz, 1H, H-13), 5.60 (t,
3
J = 8.2 Hz, 1H, H-1), 5.52 (d, J = 3.2 Hz, 1H, H-13), 4.09 (d, J = 12.9 Hz, 1H, , H-14), 4.01 (d, J
=
12.9 Hz, 1H, H-14), 3.81 (t, J = 9.4 Hz, 1H, H-6), 2.87 – 2.75 (m, 2H, H-7, H-5), 2.48 – 2.29
(
m, 4H, CH , CH OH), 2.28 – 2.04 (m, 3H, CH ), 1.65 – 1.56 (m, 1H, H-8), 1.49 (s, 3H, H-15),
2
2
2
1
3
1
1
.03 (t, J = 12.4 Hz, 1H, H-3). C NMR (100 MHz, CDCl ) δ 169.9(C-12), 139.5(C-11),
3
38.8(C-10), 126.8(C-13), 120.4(C-1), 81.4(C-6), 65.4(C-14), 63.3(C-5), 60.4(C-4), 42.7(C-7),
14

ACCEPTED MANUSCRIPT
3
2 2 2 4
6.8(C-3), 25.5(CH ), 24.0(CH ), 23.6(CH ), 18.0(C-15). HRMS (ESI) calcd for C15H20NaO
+
[
M+Na] 287.1254, found 287.1258.
4
.1.2 General procedure for the synthesis of compounds 3, 4a–4x
To a solution of compound 2 (53 mg, 0.2 mmol), EDCI (115 mg, 0.6 mmol), DMAP (1.2
mg, 0.01 mmol) and corresponded acid (0.3 mmol, 1.5 eq) in CH Cl (2 mL) was added Et N
2
2
3
(83.4 µL, 0.6 mmol) at 0 °C. The mixture was stirred for 8 h at room temperature. The reaction
was quenched with saturated aqueous NaHCO and extracted with CH Cl (3 × 15 mL). The
3
2
2
combined organic layers were washed with saturated brine, dried over Na
2
4
SO , and concentrated
to give an oily crude product, which was purified on a silica gel column to yield compound 3,
4
a–4x.
4
.1.2.1
((1aR,7aS,10aS,10bS,E)-1a-Methyl-8-methylene-9-oxo-1a,2,3,6,7,7a,8,9,10a,10b-
decahydrooxireno[2',3':9,10]cyclodeca[1,2-b]furan-5-yl)methyl cinnamate (3): White solid
1
(
yield: 86%), mp 131-133 ℃ ; H NMR (400 MHz, CDCl ) δ 7.68 (d, J = 16.0 Hz, 1H, H-18),
3
7
.54 – 7.46 (m, 2H, Ar-H), 7.45 – 7.34 (m, 3H, Ar-H), 6.41 (d, J = 16.0 Hz, 1H, H-17), 6.22 (d, J
3.5 Hz, 1H, H-13), 5.72 (t, J = 8.2 Hz, 1H, H-1), 5.55 (d, J = 3.1 Hz, 1H, H-13), 4.77 (d, J =
2.5 Hz, 1H, H-14), 4.59 (d, J = 12.5 Hz, 1H, H-14), 3.85 (t, J = 9.3 Hz, 1H, H-6), 3.01 – 2.91
=
1
(
m, 1H, H-7), 2.87 (d, J = 9.4 Hz, 1H, H-5), 2.49 – 2.11 (m, 6H, CH ), 1.72 – 1.64 (m, 1H, CH ),
2
2
1
3
1
1
1
4
.54 (s, 3H, H-15), 1.10 (t, J = 12.7 Hz, 1H, CH
2
). C NMR (100 MHz, CDCl
3
) δ 169.3(C-12),
66.5(C-16), 145.4(C-18), 138.6(C-11), 134.8(C-10), 133.9(Ar-C), 130.6(C-1), 130.5(Ar-C),
28.8(Ar-C), 128.0(Ar-C), 120.2(C-13), 117.2(C-17), 80.9(C-6), 66.8(C-14), 63.2(C-5), 59.9(C-
), 42.5(C-7), 36.5(C-3), 25.7(C-8), 24.4(C-9), 23.7(C-2), 17.9(C-15). HRMS (ESI) calcd for
+
C H NO [M+NH ] 412.2118, found 412.2122.
24
30
5
4
15

ACCEPTED MANUSCRIPT
4
.1.2.2
((1aR,7aS,10aS,10bS,E)-1a-Methyl-8-methylene-9-oxo-1a,2,3,6,7,7a,8,9,10a,10b-
decahydrooxireno[2',3':9,10]cyclodeca[1,2-b]furan-5-yl)methyl
trifluoromethyl)phenyl)acrylate (4a): White solid (yield: 92%), mp 146-148 ℃ . H NMR (400
(E)-3-(2-
1
(
MHz, CDCl ) δ 8.05 (d, J = 15.8 Hz, 1H, H-18), 7.67 (d, J = 7.9 Hz, 2H, Ar-H), 7.56 (t, J = 7.5
3
Hz, 1H, Ar-H), 7.47 (t, J = 7.6 Hz, 1H, Ar-H), 6.38 (d, J = 15.8 Hz, 1H, H-17), 6.19 (d, J = 3.4
Hz, 1H, H-13), 5.72 (t, J = 8.2 Hz, 1H, H-1), 5.54 (d, J = 3.4 Hz, 1H, H-13), 4.75 (d, J = 12.5 Hz,
1
H, H-14), 4.63 (d, J = 12.5 Hz, 1H, H-14), 3.85 (t, J = 9.3 Hz, 1H, H-6), 2.91 (t, J = 9.0 Hz, 1H,
H-5), 2.85 (d, J = 9.4 Hz, 1H, H-7), 2.51 – 2.09 (m, 6H, CH ), 1.69 (dd, J = 16.5, 8.6 Hz, 1H,
2
1
3
2 2 3
CH ), 1.52 (s, 3H, H-15), 1.08 (t, J = 12.8 Hz, 1H, CH ). C NMR (100 MHz, CDCl ) δ
1
1
69.3(C-12), 165.5(C-16), 140.7(C-18), 138.6(C-11), 134.7(C-10), 132.8(Ar-C), 132.1(C-1),
30.7(Ar-C), 129.7(Ar-C), 128.6 (q, J = 30.3 Hz, Ar-C), 127.7(Ar-C), 126.04 (q, J = 5.6 Hz, Ar-
C), 123.8 (d, J = 274.1 Hz, CF ), 121.6(C-13), 120.1(C-17), 80.9(C-6), 66.9(C-14), 63.1(C-5),
3
1
9
5
9.7(C-4), 42.5(C-7), 36.4(C-3), 25.5(C-8), 24.3(C-9), 23.7(C-2), 17.8(C-15). F NMR (376
+
MHz, CDCl ) δ –58.8 (s). HRMS (ESI) calcd for C H F NO [M+NH ] 480.1992, found
3
25 29
3
5
4
4
80.1993.
4
.1.2.3
((1aR,7aS,10aS,10bS,E)-1a-Methyl-8-methylene-9-oxo-1a,2,3,6,7,7a,8,9,10a,10b-
decahydrooxireno[2',3':9,10]cyclodeca[1,2-b]furan-5-yl)methyl (E)-3-(2-fluorophenyl)acrylate
1
(
4b): White solid (yield: 98% ), mp 110-112 ℃ . H NMR (400 MHz, CDCl
3
) δ 7.77 (d, J = 16.2
Hz, 1H, H-18), 7.48 (t, J = 7.4 Hz, 1H, Ar-H), 7.33 (dd, J = 13.2, 7.0 Hz, 1H, Ar-H), 7.13 (t, J =
.5 Hz, 1H, Ar-H), 7.10 – 7.03 (m, 1H, Ar-H), 6.49 (d, J = 16.2 Hz, 1H, H-17), 6.19 (d, J = 2.0
7
Hz, 1H, H-13), 5.70 (t, J = 8.2 Hz, 1H, H-1), 5.53 (d, J = 2.0 Hz, 1H, H-13), 4.76 (d, J = 12.5
Hz, 1H, H-14), 4.57 (d, J = 12.5 Hz, 1H, H-14), 3.84 (t, J = 9.3 Hz, 1H, H-6), 2.92 (t, J = 9.1 Hz,
1
H, H-7), 2.85 (d, J = 9.4 Hz, 1H, H-5), 2.50 – 2.05 (m, 6H, CH ), 1.74 – 1.60 (m, 1H, CH ),
2
2
16

ACCEPTED MANUSCRIPT
1
3
1
1
1
2 3
.51 (s, 3H, H-15), 1.07 (t, J = 12.9 Hz, 1H, CH ). C NMR (100 MHz, CDCl ) δ 169.2(C-12),
66.2(C-16), 161.2 (d, J = 254.1 Hz, Ar-C), 138.6(C-11), 137.9 (d, J = 2.3 Hz, C-18), 134.8(C-
0), 131.9 (d, J = 8.8 Hz, Ar-C), 130.6(C-1), 129.0 (d, J = 2.6 Hz, Ar-C), 124.4 (d, J = 3.5 Hz,
Ar-C), 122.0 (d, J = 11.5 Hz, Ar-C), 120.1(C-13), 119.8 (d, J = 6.7 Hz, C-17), 116.0 (d, J = 21.8
Hz, Ar-C), 80.9(C-6), 66.8(C-14), 63.1(C-5), 59.8(C-4), 42.5(C-7), 36.4(C-3), 25.6(C-8),
1
9
2
4.3(C-9), 23.7(C-2), 17.8(C-15). F NMR (376 MHz, CDCl ) δ –114.2 (ddd, J = 10.6, 7.5, 3.7
3
+
Hz). HRMS (ESI) calcd for C24
H29FNO
5
[M+NH
4
] 430.2024, found 430.2019.
4
.1.2.4
((1aR,7aS,10aS,10bS,E)-1a-Methyl-8-methylene-9-oxo-1a,2,3,6,7,7a,8,9,10a,10b-
decahydrooxireno[2',3':9,10]cyclodeca[1,2-b]furan-5-yl)methyl (E)-3-(2-chlorophenyl)acrylate
1
(
4c): White solid (yield: 96%), mp 114-116 ℃ . H NMR (400 MHz, CDCl
3
) δ 8.08 (d, J = 16.0
Hz, 1H, H-18), 7.57 (dd, J = 7.4, 1.7 Hz, 1H, Ar-H), 7.38 (dd, J = 7.7, 1.2 Hz, 1H, Ar-H), 7.28
m, 2H, Ar-H), 6.39 (d, J = 16.0 Hz, 1H, H-18), 6.19 (d, J = 3.4 Hz, 1H, H-13), 5.72 (t, J = 8.2
(
Hz, 1H, H-1), 5.54 (d, J = 3.1 Hz, 1H, H-13), 4.76 (d, J = 12.5 Hz, 1H, H-14), 4.60 (d, J = 12.5
Hz, 1H, H-14), 3.84 (t, J = 9.3 Hz, 1H, H-6), 3.04 – 2.89 (m, 1H, H-7), 2.85 (d, J = 9.4 Hz, 1H,
H-5), 2.47 – 2.08 (m, 6H, CH ), 1.67 (m, 1H, CH ), 1.52 (s, 3H, H-15), 1.08 (t, J = 12.8 Hz, 1H,
2
2
1
3
CH ). C NMR (100 MHz, CDCl ) δ 169.3(C-12), 166.1(C-16), 141.3(C-18), 138.7(Ar-C),
2
3
1
1
3
35.0(C-11), 134.9(C-10), 132.3(C-1), 131.3(Ar-C), 130.9(Ar-C), 130.2(Ar-C), 127.6(Ar-C),
27.2(Ar-C), 120.4(C-13), 119.9(C-17), 81.0(C-6), 67.0(C-14), 63.3(C-5), 59.9(C-4), 42.7(C-7),
6.6(C-3), 25.8(C-8), 24.5(C-9), 23.8(C-2), 18.0(C-15). HRMS (ESI) calcd for C24H29ClNO
5
+
[
M+NH ] 446.1729, found 446.1723.
4
4
.1.2.5
((1aR,7aS,10aS,10bS,E)-1a-Methyl-8-methylene-9-oxo-1a,2,3,6,7,7a,8,9,10a,10b-
decahydrooxireno[2',3':9,10]cyclodeca[1,2-b]furan-5-yl)methyl (E)-3-(2-bromophenyl)acrylate
1
(
4d): White solid (yield: 72% ), mp 120-123 ℃ . H NMR (400 MHz, CDCl ) δ 8.04 (d, J = 15.9
3
17

ACCEPTED MANUSCRIPT
Hz, 1H, H-18), 7.57 (dd, J = 11.2, 4.5 Hz, 2H, Ar-H), 7.31 (t, J = 7.5 Hz, 1H, Ar-H), 7.21 (td, J
=
7.9, 1.4 Hz, 1H, Ar-H), 6.35 (d, J = 15.9 Hz, 1H, H-17), 6.20 (d, J = 3.4 Hz, 1H, H-13), 5.73 (t,
J = 8.3 Hz, 1H, H-1), 5.54 (d, J = 3.4 Hz, 1H, H-13), 4.76 (d, J = 12.5 Hz, 1H, H-14), 4.61 (d, J
12.5 Hz, 1H, H-14), 3.85 (t, J = 9.3 Hz, 1H, H-6), 2.98 – 2.90 (m, 1H, H-7), 2.86 (d, J = 9.4
Hz, 1H, H-5), 2.49 – 2.10 (m, 6H, CH ), 1.68 (dd, J = 12.8, 8.6 Hz, 1H, CH ), 1.53 (s, 3H, H-
=
2
2
1
3
1
1
1
6
5), 1.09 (t, J = 12.8 Hz, 1H, CH ). C NMR (100 MHz, CDCl ) δ 169.3(C-12), 165.8(C-16),
2 3
43.6(C-18), 138.6(C-11), 134.7(C-10), 134.0(Ar-C), 133.3(C-1), 131.4(Ar-C), 130.7(Ar-C),
27.7(Ar-C), 127.6(Ar-C), 125.2(C-13), 120.2(Ar-C), 120.1(C-17), 80.9(C-6), 66.9(C-14),
3.1(C-5), 59.8(C-4), 42.6(C-7), 36.5(C-3), 25.6(C-8), 24.4(C-9), 23.7(C-2), 17.9(C-15). HRMS
+
(
ESI) calcd for C H BrNO [M+NH ] 490.1224, found 490.1214.
2
4
29
5
4
4
.1.2.6
((1aR,7aS,10aS,10bS,E)-1a-Methyl-8-methylene-9-oxo-1a,2,3,6,7,7a,8,9,10a,10b-
decahydrooxireno[2',3':9,10]cyclodeca[1,2-b]furan-5-yl)methyl (E)-3-(o-tolyl)acrylate (4e):
1
White solid (yield: 94% ), mp 83-85 ℃ . H NMR (400 MHz, CDCl ) δ 7.99 (d, J = 15.9 Hz, 1H,
3
H-18), 7.52 (d, J = 7.3 Hz, 1H, Ar-H), 7.29 – 7.24 (m, 1H, Ar-H), 7.20 (t, J = 7.0 Hz, 2H, Ar-H),
6
5
3
.34 (d, J = 15.9 Hz, 1H, H-17), 6.22 (d, J = 3.5 Hz, 1H, H-13), 5.73 (t, J = 8.3 Hz, 1H, H-1),
.55 (d, J = 3.2 Hz, 1H, H-13), 4.77 (d, J = 12.6 Hz, 1H, H-14), 4.60 (d, J = 12.6 Hz, 1H, H-14),
.86 (t, J = 9.3 Hz, 1H, H-6), 3.00 – 2.91 (m, 1H, H-7), 2.87 (d, J = 9.4 Hz, 1H, H-5), 2.53 – 2.11
(
m, 9H, CH2, Ar-CH
3
), 1.68 (dd, J = 13.2, 8.8 Hz, 1H, CH
2
), 1.54 (s, 3H, H-15), 1.10 (t, J = 12.7
1
3
Hz, 1H, CH
2
). C NMR (100 MHz, CDCl ) δ 169.3(C-12), 166.5(C-16), 143.1(C-18), 138.6(C-
3
1
1), 137.6(C-10), 134.9(Ar-C), 132.9(C-1), 130.7(Ar-C), 130.4(Ar-C), 130.2(Ar-C), 126.3(Ar-
C), 126.2(C-13), 120.2(Ar-C), 118.2(C-17), 80.9(C-6), 66.7(C-14), 63.1(C-5), 59.8(C-4),
4
2.5(C-7), 36.5(C-3), 25.6(C-8), 24.4(C-9), 23.7(C-2), 19.6(Ar-CH ), 17.9(C-15). HRMS (ESI)
3
+
calcd for C H NO [M+NH ] 426.2275, found 426.2281.
2
5
32
5
4
18

ACCEPTED MANUSCRIPT
4
.1.2.7
((1aR,7aS,10aS,10bS,E)-1a-Methyl-8-methylene-9-oxo-1a,2,3,6,7,7a,8,9,10a,10b-
decahydrooxireno[2',3':9,10]cyclodeca[1,2-b]furan-5-yl)methyl
(E)-3-(2-
1
methoxyphenyl)acrylate (4f): White solid (yield: 89%), mp 172-174 ℃ . H NMR (400 MHz,
CDCl ) δ 7.98 (d, J = 16.1 Hz, 1H, H-18), 7.46 (d, J = 7.4 Hz, 1H, Ar-H), 7.35 (t, J = 7.7 Hz, 1H,
3
Ar-H), 7.00 – 6.87 (m, 2H, Ar-H), 6.50 (d, J = 16.1 Hz, 1H, H-17), 6.21 (d, J = 3.3 Hz, 1H, H-
1
4
7
3), 5.72 (t, J = 8.0 Hz, 1H, H-1), 5.54 (d, J = 2.9 Hz, 1H, H-13), 4.75 (d, J = 12.5 Hz, 1H, H-14),
.59 (d, J = 12.5 Hz, 1H, H-14), 3.96 – 3.79 (m, 4H, H-6, Ar-OCH ), 3.00 (t, J = 8.8 Hz, 1H, H-
), 2.89 (d, J = 9.4 Hz, 1H, H-5), 2.54 – 2.09 (m, 6H, CH ), 1.67 (t, J = 11.1 Hz, 1H, CH ), 1.54
). C NMR (100 MHz, CDCl ) δ 169.4(C-12),
3
2
2
1
3
(s, 3H, H-15), 1.11 (t, J = 12.8 Hz, 1H, CH
2
3
1
1
6
2
67.1(C-16), 158.3(Ar-C), 141.0(C-11), 138.6(C-18), 135.0(C-10), 131.7(Ar-C), 130.7(C-1),
29.1(Ar-C), 122.9(Ar-C), 120.6(Ar-C), 120.3(C-13), 117.7(C-17), 111.1(Ar-C), 81.0(C-6),
6.8(C-14), 63.2(C-5), 59.9(C-4), 55.4(OCH ), 42.6(C-7), 36.5(C-3), 25.8(C-8), 24.6(C-9),
3
+
3.8(C-2), 17.9(C-15). HRMS (ESI) calcd for C H NO [M+NH ] 442.2224, found 442.2232.
2
5
32
6
4
4
.1.2.8
((1aR,7aS,10aS,10bS,E)-1a-Methyl-8-methylene-9-oxo-1a,2,3,6,7,7a,8,9,10a,10b-
decahydrooxireno[2',3':9,10]cyclodeca[1,2-b]furan-5-yl)methyl (E)-3-(2-ethoxyphenyl)acrylate
1
(
4g): White solid (yield: 89%), mp 143-145 ℃ . H NMR (400 MHz, CDCl ) δ 8.03 (d, J = 16.1
3
Hz, 1H, H-18), 7.48 (d, J = 7.6 Hz, 1H, Ar-H), 7.33 (t, J = 7.8 Hz, 1H, Ar-H), 6.97 – 6.89 (m,
H, Ar-H), 6.52 (d, J = 16.1 Hz, 1H, H-17), 6.29 – 6.19 (m, 1H, H-13), 5.74 (t, J = 8.0 Hz, 1H,
2
H-1), 5.55 (d, J = 2.9 Hz, 1H, H-13), 4.76 (d, J = 12.6 Hz, 1H, H-14), 4.62 (d, J = 12.6 Hz, 1H,
H-14), 4.10 (q, J = 6.9 Hz, 2H, Ar-OCH CH ), 3.86 (t, J = 9.3 Hz, 1H, H-6), 3.04 – 2.95 (m, 1H,
2
3
H-7), 2.89 (d, J = 9.4 Hz, 1H, H-5), 2.53 – 2.12 (m, 6H, CH ), 1.72 – 1.63 (m, 1H, CH ), 1.55 (s,
2
2
1
3
3
H, H-15), 1.47 (t, J = 6.9 Hz, 3H, Ar-OCH CH ), 1.12 (t, J = 12.6 Hz, 1H, CH ). C NMR (100
2 3 2
MHz, CDCl ) δ 169.3(C-12), 167.0(C-16), 157.5(Ar-C), 140.9(C-11), 138.5(C-18), 134.9(C-10),
3
19

ACCEPTED MANUSCRIPT
1
1
3
31.6(Ar-C), 130.1(C-11), 128.7(Ar-C), 122.7(Ar-C), 120.3(Ar-C), 120.1(C-13), 117.3(C-17),
11.9(Ar-C), 80.8(C-6), 66.5(C-14), 63.7(C-5), 63.0(OCH CH ), 59.8(C-4), 42.4(C-7), 36.4(C-
2
3
), 25.5(C-8), 24.3(C-9), 23.6(C-2), 17.7(C-15), 14.5(OCH CH ). HRMS (ESI) calcd for
2
3
+
C H NO [M+NH ] 456.2381, found 456.2380.
26
34
6
4
4
.1.2.9
decahydrooxireno[2',3':9,10]cyclodeca[1,2-b]furan-5-yl)methyl
trifluoromethyl)phenyl)acrylate (4h): White solid (yield: 69%), mp 124-126 ℃ . H NMR (400
MHz, CDCl ) δ 7.80 – 7.60 (m, 4H, H-18, Ar-H), 7.53 (t, J = 7.7 Hz, 1H, Ar-H), 6.49 (d, J =
((1aR,7aS,10aS,10bS,E)-1a-Methyl-8-methylene-9-oxo-1a,2,3,6,7,7a,8,9,10a,10b-
(E)-3-(3-
1
(
3
1
6.0 Hz, 1H, H-17), 6.26 (d, J = 3.3 Hz, 1H, H-13), 5.75 (t, J = 8.2 Hz, 1H, H-1), 5.57 (d, J = 2.9
Hz, 1H, H-13), 4.80 (d, J = 12.5 Hz, 1H, H-14), 4.62 (d, J = 12.5 Hz, 1H, H-14), 3.87 (t, J = 9.3
Hz, 1H, H-6), 2.93 (dd, J = 15.1, 6.0 Hz, 1H, H-7), 2.88 (d, J = 9.4 Hz, 1H, H-5), 2.56 – 2.14 (m,
1
3
6
H, CH ), 1.76 – 1.64 (m, 1H, CH ), 1.56 (s, 3H, H-15), 1.13 (t, J = 12.8 Hz, 1H, CH ). C
2 2 2
NMR (100 MHz, CDCl ) δ 169.3(C-12), 166.0(C-16), 143.7(C-18), 138.7(C-11), 134.9(C-10),
3
1
3
8
2
34.8(Ar-C), 131.5 (d, J = 32.3 Hz, Ar-C), 131.1(C-1), 130.8(Ar-C), 129.5(Ar-C), 126.9 (d, J =
.7 Hz, Ar-C), 124.6 (d, J = 3.8 Hz, Ar-C), 123.7(d, J =273.30, CF ), 120.3(C-13), 119.3(C-17),
3
1.0(C-6), 66.9(C-14), 63.3(C-5), 59.9(C-4), 42.7(C-7), 36.6(C-3), 25.7(C-8), 24.4(C-9), 23.8(C-
1
9
3 29 3 5
), 18.0(C-15). F NMR (376 MHz, CDCl ) δ –62.89 (s). HRMS (ESI) calcd for C25H F NO
+
[
M+NH
4
] 480.1992, found 480.1992.
4.1.2.10
((1aR,7aS,10aS,10bS,E)-1a-Methyl-8-methylene-9-oxo-1a,2,3,6,7,7a,8,9,10a,10b-
decahydrooxireno[2',3':9,10]cyclodeca[1,2-b]furan-5-yl)methyl (E)-3-(3-fluorophenyl)acrylate
1
(
4i): White solid (yield: 76% ), mp 127-129 ℃ . H NMR (400 MHz, CDCl
3
) δ 7.63 (d, J = 16.0
Hz, 1H, H-18), 7.35 (dd, J = 13.8, 7.8 Hz, 1H, Ar-H), 7.27 (d, J = 6.8 Hz, 1H, Ar-H), 7.19 (d, J =
.5 Hz, 1H, Ar-H), 7.08 (t, J = 8.2 Hz, 1H, Ar-H), 6.40 (d, J = 16.0 Hz, 1H, H-17), 6.23 (d, J =
9
20

ACCEPTED MANUSCRIPT
3
.4 Hz, 1H, H-13), 5.73 (t, J = 8.2 Hz, 1H, H-1), 5.55 (d, J = 3.4 Hz, 1H, H-13), 4.78 (d, J = 12.5
Hz, 1H, H-14), 4.59 (d, J = 12.5 Hz, 1H, H-14), 3.86 (t, J = 9.3 Hz, 1H, H-6), 2.93 (dd, J = 14.8,
5
1
1
.8 Hz, 1H, H-7), 2.87 (d, J = 9.4 Hz, 1H, H-5), 2.50 – 2.11 (m, 6H, CH ), 1.70 (m, 1H, CH ),
2 2
13
.54 (s, 3H, H-15), 1.11 (m, 1H, CH ). C NMR (100 MHz, CDCl ) δ 169.3(C-12), 166.1(C-16),
2
3
62.9 (d, J = 247.0 Hz, Ar-C), 144.0 (d, J = 2.5 Hz, C-18), 138.7(C-11), 136.2 (d, J = 7.7 Hz,
Ar-C), 134.8(C-10), 130.7(C-1), 130.5 (d, J = 8.2 Hz, Ar-C), 124.1 (d, J = 2.7 Hz, Ar-C),
1
6
1
20.2(C-13), 118.7(C-17), 117.3 (d, J = 21.4 Hz, Ar-C), 114.3 (d, J = 22.0 Hz, Ar-C), 80.9(C-6),
6.8(C-14), 63.2(C-5), 59.9(C-4), 42.6(C-7), 36.5(C-3), 25.7(C-8), 24.4(C-9), 23.8(C-2), 17.9(C-
1
9
3
5). F NMR (376 MHz, CDCl ) δ –112.3 (dd, J = 14.8, 8.9 Hz). HRMS (ESI) calcd for
+
C H FNO [M+NH ] 430.2024, found 430.2024.
24
29
5
4
4
.1.2.11
((1aR,7aS,10aS,10bS,E)-1a-Methyl-8-methylene-9-oxo-1a,2,3,6,7,7a,8,9,10a,10b-
decahydrooxireno[2',3':9,10]cyclodeca[1,2-b]furan-5-yl)methyl (E)-3-(3-chlorophenyl)acrylate
1
(
4j): White solid (yield: 69% ), mp 114-117 ℃ . H NMR (400 MHz, CDCl ) δ 7.59 (d, J = 16.0
3
Hz, 1H, H-18), 7.46 (s, 1H, Ar-H), 7.37-7.30 (m, 3H, Ar-H), 6.40 (d, J = 16.0 Hz, 1H, H-17),
.21 (d, J = 3.2 Hz, 1H, H-13), 5.71 (t, J = 8.2 Hz, 1H, H-1), 5.54 (d, J = 2.8 Hz, 1H, H-13), 4.76
d, J = 12.5 Hz, 1H, H-14), 4.59 (d, J = 12.5 Hz, 1H, H-14), 3.85 (t, J = 9.3 Hz, 1H, H-6), 2.91
dd, J = 14.7, 5.8 Hz, 1H, H-7), 2.85 (d, J = 9.4 Hz, 1H, H-5), 2.50 – 2.09 (m, 6H, CH ), 1.73 –
). C NMR (100 MHz,
) δ 169.2(C-12), 166.0(C-16), 143.7(C-18), 138.6(C-11), 135.8(C-10), 134.8(Ar-C),
34.7(C-1), 130.6 (Ar-C), 130.2(Ar-C), 130.1(Ar-C), 127.7(Ar-C), 126.2(Ar-C), 120.2(C-13),
6
(
(
2
1
3
1
2 2
.62 (m, 1H, CH ), 1.53 (s, 3H, H-15), 1.09 (t, J = 13.0 Hz, 1H, CH
CDCl
3
1
1
18.8(C-17), 80.9(C-6), 66.8(C-14), 63.1(C-5), 59.9(C-4), 42.5(C-7), 36.5(C-3), 25.6(C-8),
+
2
4.3(C-9), 23.7(C-2), 17.9(C-15). HRMS (ESI) calcd for C H ClNO [M+NH ] 446.1729,
2
4
29
5
4
found 446.1723.
21

ACCEPTED MANUSCRIPT
4
.1.2.12
((1aR,7aS,10aS,10bS,E)-1a-Methyl-8-methylene-9-oxo-1a,2,3,6,7,7a,8,9,10a,10b-
decahydrooxireno[2',3':9,10]cyclodeca[1,2-b]furan-5-yl)methyl (E)-3-(3-bromophenyl)acrylate
1
(
4k): White solid (yield: 89%), mp 118-120 ℃ . H NMR (400 MHz, CDCl ) δ 7.62 (s, 1H, Ar-H),
3
7
7
.57 (d, J = 16.0 Hz, 1H, H-18), 7.48 (d, J = 7.9 Hz, 1H, Ar-H), 7.40 (d, J = 7.8 Hz, 1H, Ar-H),
.27 – 7.22 (m, 1H, Ar-H), 6.39 (d, J = 16.0 Hz, 1H, H-17), 6.21 (d, J = 3.4 Hz, 1H, H-13), 5.71
(
t, J = 8.2 Hz, 1H, H-1), 5.54 (d, J = 3.4 Hz, 1H, H-13), 4.76 (d, J = 12.6 Hz, 1H, H-14), 4.58 (d,
J = 12.6 Hz, 1H, H-14), 3.84 (t, J = 9.3 Hz, 1H, H-6), 2.97 – 2.88 (m, 1H, H-7), 2.85 (d, J = 9.4
Hz, 1H, H-5), 2.50 – 2.10 (m, 6H, CH ), 1.73 – 1.63 (m, 1H, CH ), 1.52 (s, 3H, H-15), 1.08 (t, J
). C NMR (100 MHz, CDCl ) δ 169.2(C-12), 166.0(C-16), 143.5(C-18),
2
2
1
3
=
12.8 Hz, 1H, CH
2
3
1
1
4
38.6(C-11), 136.0(C-10), 134.7(Ar-C), 133.1(C-1), 130.6(Ar-C), 130.5(Ar-C), 130.4(Ar-C),
26.6(Ar-C), 122.8(Ar-C), 120.1(C-13), 118.8(C-17), 80.9(C-6), 66.8(C-14), 63.1(C-5), 59.8(C-
), 42.5(C-7), 36.4(C-3), 25.5(C-8), 24.3(C-9), 23.7(C-2), 17.8(C-15). HRMS (ESI) calcd for
+
C H BrNO [M+NH ] 490.1224, found 490.1218.
24
29
5
4
4
.1.2.13
((1aR,7aS,10aS,10bS,E)-1a-Methyl-8-methylene-9-oxo-1a,2,3,6,7,7a,8,9,10a,10b-
decahydrooxireno[2',3':9,10]cyclodeca[1,2-b]furan-5-yl)methyl (E)-3-(m-tolyl)acrylate (4l):
1
White solid (yield: 88%), mp 172-174 ℃ . H NMR (400 MHz, CDCl ) δ 7.67 (d, J = 16.0 Hz,
3
1
H, H-18), 7.36 – 7.27 (m, 3H, Ar-H), 7.21 (d, J = 7.2 Hz, 1H, Ar-H), 6.42 (d, J = 16.0 Hz, 1H,
H-17), 6.24 (d, J = 3.5 Hz, 1H, H-13), 5.74 (t, J = 8.2 Hz, 1H, H-1), 5.57 (d, J = 3.1 Hz, 1H, H-
1
6
1
3), 4.78 (d, J = 12.5 Hz, 1H, H-14), 4.61 (d, J = 12.5 Hz, 1H, H-14), 3.87 (t, J = 9.3 Hz, 1H, H-
), 3.02 – 2.94 (m, 1H, H-7), 2.89 (d, J = 9.4 Hz, 1H, H-5), 2.54 – 2.13 (m, 9H, CH Ar-CH ),
2
,
3
1
3
.75 – 1.66 (m, 1H, CH ), 1.56 (s, 3H, H-15), 1.12 (t, J = 12.7 Hz, 1H, CH ). C NMR (100
2
2
MHz, CDCl ) δ 169.2(C-12), 166.5(C-16), 145.5(C-18), 138.6(Ar-C), 138.4(C-11), 134.8(C-10),
3
1
33.9(Ar-C), 131.2(C-1), 130.4(Ar-C), 128.7(Ar-C), 128.6(Ar-C), 125.1(Ar-C), 120.1(C-13),
22

ACCEPTED MANUSCRIPT
1
2
4
17.0(C-17), 80.9(C-6), 66.7(C-14), 63.1(C-5), 59.8(C-4), 42.5(C-7), 36.4(C-3), 25.6(C-8),
+
4.4(C-9), 23.7(C-2), 21.1(Ar-CH ), 17.8(C-15). HRMS (ESI) calcd for C H O [M+NH ]
3
25 32
5
4
26.2275，found 426.2283.
4
.1.2.14
((1aR,7aS,10aS,10bS,E)-1a-Methyl-8-methylene-9-oxo-1a,2,3,6,7,7a,8,9,10a,10b-
(E)-3-(3-
decahydrooxireno[2',3':9,10]cyclodeca[1,2-b]furan-5-yl)methyl
1
methoxyphenyl)acrylate (4m): White solid (yield: 92%), mp 96-98 ℃. H NMR (400 MHz,
CDCl ) δ 7.63 (d, J = 16.0 Hz, 1H, H-18), 7.29 (d, J = 7.9 Hz, 1H, Ar-H), 7.08 (d, J = 7.7 Hz, 1H,
3
Ar-H), 7.00 (s, 1H, Ar-H), 6.92 (dd, J = 8.2, 2.1 Hz, 1H, Ar-H), 6.39 (d, J = 16.0 Hz, 1H, H-17),
6
.22 (d, J = 3.5 Hz, 1H, H-13), 5.72 (t, J = 8.2 Hz, 1H, H-1), 5.54 (d, J = 3.1 Hz, 1H, H-13), 4.76
(d, J = 12.5 Hz, 1H, H-14), 4.58 (d, J = 12.5 Hz, 1H, H-14), 3.85 (t, J = 9.3 Hz, 1H, H-6), 3.80 (s,
3
H, Ar-OCH ), 3.00 – 2.91 (m, 1H, H-7), 2.86 (d, J = 9.4 Hz, 1H, H-7), 2.51 – 2.10 (m, 6H,
3
1
3
CH
2
), 1.73 – 1.63 (m, 1H, CH
2 2
), 1.53 (s, 3H, H-15), 1.09 (t, J = 12.7 Hz, 1H, CH ). C NMR
(
100 MHz, CDCl ) δ 169.3(C-12), 166.4(C-16), 159.8(Ar-C), 145.3(C-18), 138.7(C-11),
3
1
1
7
35.3(Ar-C), 134.8(C-10), 130.6(C-1), 129.8(Ar-C), 120.7(Ar-C), 120.2(C-13), 117.5(C-17),
16.3(Ar-C), 112.8(Ar-C), 80.9(C-6), 66.8(C-14), 63.2(C-5), 59.9(C-4), 55.2(Ar-OCH ), 42.6(C-
3
), 36.5(C-3), 25.7(C-8), 24.4(C-9), 23.7(C-2), 17.9(C-15). HRMS (ESI) calcd for C H NO
6
2
5
32
+
[
M+NH ] 442.2224, found 442.2229.
4
4
.1.2.15
((1aR,7aS,10aS,10bS,E)-1a-Methyl-8-methylene-9-oxo-1a,2,3,6,7,7a,8,9,10a,10b-
(E)-3-(4-
trifluoromethyl)phenyl)acrylate (4n): White solid (yield: 72%), mp 164-166 ℃. H NMR (400
MHz, CDCl ) δ 7.66 (d, J = 16.0 Hz, 1H, H-18), 7.63 – 7.56 (m, 4H, Ar-H), 6.47 (d, J = 16.0 Hz,
decahydrooxireno[2',3':9,10]cyclodeca[1,2-b]furan-5-yl)methyl
1
(
3
1
H, H-17), 6.19 (d, J = 3.5 Hz, 1H, H-13), 5.72 (t, J = 8.2 Hz, 1H, H-1), 5.53 (d, J = 3.1 Hz, 1H,
23

ACCEPTED MANUSCRIPT
H-13), 4.77 (d, J = 12.5 Hz, 1H, H-14), 4.60 (d, J = 12.5 Hz, 1H, H-14), 3.85 (t, J = 9.3 Hz, 1H,
H-6), 2.93 (dd, J = 14.9, 5.9 Hz, 1H, H-7), 2.86 (d, J = 9.4 Hz, 1H, H-5), 2.51 – 2.09 (m, 6H,
1
3
CH ), 1.73 – 1.65 (m, 1H, CH ), 1.52 (s, 3H, H-15), 1.08 (t, J = 12.7 Hz, 1H, CH ). C NMR
2
2
2
(
100 MHz, CDCl ) δ 169.2(C-12), 165.9(C-16), 143.4(C-18), 138.7(C-11), 137.4(Ar-C),
3
1
34.6(C-10), 131.6 (q, J = 32.6 Hz, Ar-C), 130.7(C-1), 128.1(Ar-C), 125.72 (q, J = 3.7 Hz, Ar-
C), 123.6 (d, J = 272.3 Hz, CF ), 120.1(C-13), 119.9(C-17), 80.9(C-6), 66.9(C-14), 63.1(C-5),
3
1
9
5
9.8(C-4), 42.5(C-7), 36.4(C-3), 25.5(C-8), 24.3(C-9), 23.7(C-2), 17.8(C-15). F NMR (376
+
MHz, CDCl
3
) δ –62.9 (s). HRMS (ESI) calcd for C25
H
29
F
3
NO
5
[M+NH
4
] 480.1992, found
4
80.2000.
4
.1.2.16
((1aR,7aS,10aS,10bS,E)-1a-Methyl-8-methylene-9-oxo-1a,2,3,6,7,7a,8,9,10a,10b-
decahydrooxireno[2',3':9,10]cyclodeca[1,2-b]furan-5-yl)methyl (E)-3-(4-fluorophenyl)acrylate
1
(
4o): White solid (yield: 93%), mp 78-80 ℃ . H NMR (400 MHz, CDCl ) δ 7.63 (d, J = 16.0 Hz,
3
1
H, H-18), 7.55 – 7.43 (m, 2H, Ar-H), 7.06 (t, J = 8.6 Hz, 2H, Ar-H), 6.32 (d, J = 16.0 Hz, 1H,
H-17), 6.21 (d, J = 3.5 Hz, 1H, H-13), 5.72 (t, J = 8.2 Hz, 1H, H-1), 5.54 (d, J = 3.5 Hz, 1H, H-
1
6
1
3), 4.76 (d, J = 12.5 Hz, 1H, H-14), 4.58 (d, J = 12.5 Hz, 1H, H-14), 3.85 (t, J = 9.3 Hz, 1H, H-
), 3.01 – 2.90 (m, 1H, H-7), 2.87 (d, J = 9.4 Hz, 1H, H-5), 2.51 – 2.10 (m, 6H, CH ), 1.73 –
2
1
3
.64 (m, 1H, CH
) δ 169.3(C-12), 166.4(C-16), 163.9 (d, J = 251.9 Hz, Ar-C), 144.1(C-18), 138.7(C-11),
34.8(C-10), 130.6(C-1), 130.3 (d, J = 3.2 Hz, Ar-C), 129.9 (d, J = 8.6 Hz, Ar-C), 120.2(C-13),
17.0(C-17), 116.0 (d, J = 22.0 Hz, Ar-C), 80.9(C-6), 66.8(C-14), 63.2(C-5), 59.9(C-4), 42.6(C-
2 2
), 1.53 (s, 3H, H-15), 1.10 (t, J = 12.7 Hz, 1H, CH ). C NMR (100 MHz,
CDCl
3
1
1
7
1
1
9
), 36.5(C-3), 25.7(C-8), 24.4(C-9), 23.7(C-2), 17.9(C-15). F NMR (376 MHz, CDCl ) δ –
3
+
09.0 (s). HRMS (ESI) calcd for C H FNO [M+NH ] 430.2024, found 430.2026.
2
4
29
5
4
24

ACCEPTED MANUSCRIPT
4
.1.2.17
((1aR,7aS,10aS,10bS,E)-1a-Methyl-8-methylene-9-oxo-1a,2,3,6,7,7a,8,9,10a,10b-
decahydrooxireno[2',3':9,10]cyclodeca[1,2-b]furan-5-yl)methyl (E)-3-(4-chlorophenyl)acrylate
1
(
4p): White solid (yield: 90%), mp 148-150 ℃ . H NMR (400 MHz, CDCl ) δ 7.61 (d, J = 16.0
3
Hz, 1H, H-18), 7.42 (d, J = 8.5 Hz, 2H, Ar-H), 7.34 (d, J = 8.5 Hz, 2H, Ar-H), 6.37 (d, J = 16.0
Hz, 1H, H-17), 6.21 (d, J = 3.5 Hz, 1H, H-13), 5.72 (t, J = 8.2 Hz, 1H, H-1), 5.54 (d, J = 3.2 Hz,
1
1
1
H, H-13), 4.76 (d, J = 12.5 Hz, 1H, H-14), 4.58 (d, J = 12.5 Hz, 1H, H-14), 3.85 (t, J = 9.3 Hz,
H, H-6), 3.00 – 2.89 (m, 1H, H-7), 2.86 (d, J = 9.4 Hz, 1H, H-5), 2.52 – 2.10 (m, 6H, CH ),
). C NMR (100
) δ 169.3(C-12), 166.2(C-16), 143.9(C-18), 138.7(C-11), 136.3(C-10), 134.8(Ar-C),
32.5(Ar-C), 130.7(C-1), 129.2(Ar-C), 129.1(Ar-C), 120.2(C-13), 117.9(C-17), 80.9(C-6),
2
1
3
2 2
.72 – 1.63 (m, 1H, CH ), 1.53 (s, 3H, H-15), 1.09 (t, J = 12.7 Hz, 1H, CH
MHz, CDCl
3
1
6
1
6.8(C-14), 63.2(C-5), 59.9(C-4), 42.6(C-7), 36.5(C-3), 25.7(C-8), 24.4(C-9), 23.7(C-2), 17.9(C-
+
5). HRMS (ESI) calcd for C H ClNO [M+NH ] 446.1729, found 446.1732.
2
4
29
5
4
4
.1.2.18
((1aR,7aS,10aS,10bS,E)-1a-Methyl-8-methylene-9-oxo-1a,2,3,6,7,7a,8,9,10a,10b-
(E)-3-(4-
decahydrooxireno[2',3':9,10]cyclodeca[1,2-b]furan-5-yl)methyl
1
bromophenyl)acrylate(4q): White solid (yield: 86%), mp 177-179 ℃ . H NMR (400 MHz,
CDCl ) δ 7.59 (d, J = 16.0 Hz, 1H, H-18), 7.49 (d, J = 8.4 Hz, 2H, Ar-H), 7.35 (d, J = 8.4 Hz, 2H,
3
Ar-H), 6.39 (d, J = 16.0 Hz, 1H, H-17), 6.21 (d, J = 3.5 Hz, 1H, H-13), 5.72 (t, J = 8.2 Hz, 1H,
H-1), 5.53 (d, J = 3.1 Hz, 1H, H-13), 4.76 (d, J = 12.5 Hz, 1H, H-14), 4.58 (d, J = 12.5 Hz, 1H,
H-14), 3.85 (t, J = 9.3 Hz, 1H, H-6), 2.93 (m, 1H, H-7), 2.86 (d, J = 9.4 Hz, 1H, H-5), 2.51 –
2
.11 (m, 6H, CH ), 1.73 – 1.63 (m, 1H, CH ), 1.53 (s, 3H, H-15), 1.09 (t, J = 12.7 Hz, 1H, CH ).
2 2 2
1
3
C NMR (101 MHz, CDCl ) δ 169.3(C-12), 166.2(C-16), 144.0(C-18), 138.6(C-11), 134.7(C-
3
1
0), 132.9(Ar-C), 132.1(Ar-C), 130.7(C-1), 129.4(Ar-C), 124.7(Ar-C), 120.2(C-13), 118.0(C-17),
25

ACCEPTED MANUSCRIPT
8
2
0.9(C-6), 66.8(C-14), 63.1(C-5), 59.9(C-4), 42.5(C-7), 36.5(C-3), 25.6(C-8), 24.4(C-9), 23.7(C-
+
), 17.9(C-15). HRMS (ESI) calcd for C H BrNO [M+NH ] 490.1224, found 490.1221.
2
4
29
5
4
4
.1.2.19
((1aR,7aS,10aS,10bS,E)-1a-Methyl-8-methylene-9-oxo-1a,2,3,6,7,7a,8,9,10a,10b-
decahydrooxireno[2',3':9,10]cyclodeca[1,2-b]furan-5-yl)methyl (E)-3-(p-tolyl)acrylate (4r):
1
White solid (yield: 62%), mp 153-155 ℃ . H NMR (400 MHz, CDCl ) δ 7.66 (d, J = 16.0 Hz, 1H,
3
H-18), 7.40 (d, J = 8.0 Hz, 2H, Ar-H), 7.19 (d, J = 7.9 Hz, 2H, Ar-H), 6.36 (d, J = 16.0 Hz, 1H,
H-17), 6.23 (d, J = 3.5 Hz, 1H, H-13), 5.73 (t, J = 8.2 Hz, 1H, H-1), 5.55 (d, J = 3.1 Hz, 1H, H-
1
6
1
3), 4.77 (d, J = 12.5 Hz, 1H, H-14), 4.59 (d, J = 12.5 Hz, 1H, H-14), 3.86 (t, J = 9.3 Hz, 1H, H-
), 3.01 – 2.92 (m, 1H, H-7), 2.88 (d, J = 9.4 Hz, 1H, H-5), 2.52 – 2.12 (m, 9H, CH Ar-CH ),
2
,
3
1
3
.68 (dd, J = 12.8, 8.5 Hz, 1H, CH
2
), 1.55 (s, 3H, H-15), 1.11 (t, J = 12.7 Hz, 1H, CH
2
). C
NMR (100 MHz, CDCl
3
) δ 169.3(C-12), 166.7(C-16), 145.5(C-18), 141.0(Ar-C), 138.7(C-13),
1
8
2
4
35.0(C-10), 131.3(Ar-C), 130.6(C-1), 129.6(Ar-C), 128.1(Ar-C), 120.3(C-13), 116.1(C-17),
1.0(C-6), 66.7(C-14), 63.2(C-5), 59.9(C-4), 42.6(C-7), 36.5(C-3), 25.8(C-8), 24.5(C-9), 23.8(C-
+
), 21.4(Ar-CH ), 17.9(C-15). HRMS (ESI) calcd for C H NO [M+NH ] 426.2275, found
3
25 32
5
4
26.2281.
4
.1.2.20
((1aR,7aS,10aS,10bS,E)-1a-Methyl-8-methylene-9-oxo-1a,2,3,6,7,7a,8,9,10a,10b-
(E)-3-(4-
decahydrooxireno[2',3':9,10]cyclodeca[1,2-b]furan-5-yl)methyl
1
isopropylphenyl)acrylate (4s): White solid (yield: 71%), mp 147-149 ℃ . H NMR (400 MHz,
CDCl ) δ 7.66 (d, J = 16.0 Hz, 1H, H-18), 7.43 (d, J = 8.1 Hz, 2H, Ar-H), 7.23 (d, J = 8.1 Hz, 2H,
3
Ar-H), 6.36 (d, J = 16.0 Hz, 1H, H-17), 6.22 (d, J = 3.5 Hz, 1H, H-13), 5.72 (t, J = 8.2 Hz, 1H,
H-1), 5.55 (d, J = 3.1 Hz, 1H, H-13), 4.76 (d, J = 12.5 Hz, 1H, H-14), 4.58 (d, J = 12.5 Hz, 1H,
H-14), 3.86 (t, J = 9.3 Hz, 1H, H-6), 2.93 (m, 3H, H-5, -7, Ar-CH), 2.51 – 2.10 (m, 6H, CH2),
1
.68 (dd, J = 12.9, 8.8 Hz, 1H, CH ), 1.54 (s, 3H, H-15), 1.23 (d, J = 6.9 Hz, 6H,Ar-CH(CH ) ),
2 3 2
26

ACCEPTED MANUSCRIPT
1
3
1
1
1
3
2 3
.10 (t, J = 13.2 Hz, 1H, CH ). C NMR (100 MHz, CDCl ) δ 169.3(C-12), 166.7(C-16),
51.8(Ar-C), 145.4(C-18), 138.6(C-11), 134.9(C-10), 131.6(Ar-C), 130.5(C-1), 128.1(Ar-C),
26.9(Ar-C), 120.2(C-13), 116.2(C-17), 80.9(C-6), 66.7(C-14), 63.1(C-5), 59.9(C-4), 42.5(C-7),
6.5(C-3), 33.9(Ar-CHCH3), 25.7(C-8), 24.4(C-9), 23.7(C-2), 23.6(Ar-CHCH3), 17.9(C-15).
+
HRMS (ESI) calcd for C H NO [M+NH ] 454.2588, found 454.2594.
2
7
36
5
4
4
.1.2.21
((1aR,7aS,10aS,10bS,E)-1a-Methyl-8-methylene-9-oxo-1a,2,3,6,7,7a,8,9,10a,10b-
(E)-3-(4-
decahydrooxireno[2',3':9,10]cyclodeca[1,2-b]furan-5-yl)methyl
1
methoxyphenyl)acrylate (4t): White solid (yield: 77%), mp 185-188 ℃ . H NMR (400 MHz,
CDCl ) δ 7.63 (d, J = 15.9 Hz, 1H, H-18), 7.45 (d, J = 8.7 Hz, 2H, Ar-H), 6.89 (d, J = 8.7 Hz,
3
2
1
1
7
1
1
1
4
H, Ar-H), 6.27 (d, J = 15.9 Hz, 1H, H-17), 6.23 (d, J = 3.5 Hz, 1H, H-13), 5.72 (t, J = 8.2 Hz,
H, H-1), 5.55 (d, J = 3.1 Hz, 1H, H-13), 4.76 (d, J = 12.5 Hz, 1H, H-14), 4.57 (d, J = 12.5 Hz,
H, H-14), 3.89 – 3.83 (m, 1H, H-6), 3.82 (s, 3H, Ar-OCH ), 2.97 (dd, J = 14.8, 5.8 Hz, 1H, H-
3
), 2.88 (d, J = 9.4 Hz, 1H, H-5), 2.51 – 2.12 (m, 6H, CH ), 1.67 (dd, J = 12.7, 8.6 Hz, 1H, CH ),
2
2
1
3
.54 (s, 3H, H-15), 1.10 (t, J = 12.7 Hz, 1H, CH ). C NMR (100 MHz, CDCl ) δ 169.3(C-12),
2
3
66.9(C-16), 161.5(Ar-C), 145.1(C-18), 138.7(C-11), 135.0(C-10), 130.5(C-1), 129.7(Ar-C),
26.7(Ar-C), 120.3(C-13), 114.6(C-17), 114.3(Ar-C), 81.0(C-6), 66.7(C-14), 63.2(C-5), 59.9(C-
), 55.3(Ar-OCH
3
), 42.6(C-7), 36.5(C-3), 25.8(C-8), 24.5(C-9), 23.8(C-2), 17.9(C-15). HRMS
+
(ESI) calcd for C25
H32NO
6
[M+NH
4
] 442.2224, found 442.2230.
4
.1.2.22
((1aR,7aS,10aS,10bS,E)-1a-Methyl-8-methylene-9-oxo-1a,2,3,6,7,7a,8,9,10a,10b-
decahydrooxireno[2',3':9,10]cyclodeca[1,2-b]furan-5-yl)methyl (E)-3-(4-ethoxyphenyl)acrylate
1
(
4u): White solid (yield: 90%), mp 142-145 ℃ . H NMR (400 MHz, CDCl
3
) δ 7.61 (d, J = 15.9
Hz, 1H, H-18), 7.42 (d, J = 8.6 Hz, 2H, Ar-H), 6.86 (d, J = 8.7 Hz, 2H, Ar-H), 6.25 (d, J = 15.9
Hz, 1H, H-17), 6.21 (d, J = 3.4 Hz, 1H, H-13), 5.70 (t, J = 8.1 Hz, 1H, H-1), 5.54 (d, J = 3.2 Hz,
27

ACCEPTED MANUSCRIPT
1
2
1
=
H, H-13), 4.74 (d, J = 12.5 Hz, 1H, H-14), 4.56 (d, J = 12.5 Hz, 1H, H-14), 4.03 (q, J = 6.9 Hz,
H,OCH CH ), 3.84 (t, J = 9.3 Hz, 1H, H-6), 2.95 (t, J = 8.9 Hz, 1H, H-7), 2.86 (d, J = 9.4 Hz,
2
3
H, H-5), 2.49 – 2.10 (m, 6H, CH ), 1.66 (t, J = 10.7 Hz, 1H, CH ), 1.53 (s, 3H, H-15), 1.39 (t, J
2
2
1
3
7.0 Hz, 3H,OCH CH ), 1.09 (t, J = 12.7 Hz, 1H, CH ). C NMR (100 MHz, CDCl ) δ
2
3
2
3
1
1
6
1
4
69.3(C-12), 166.8(C-16), 160.9(Ar-C), 145.1(C-18), 138.6(C-11), 135.0(C-10), 130.3(C-1),
29.7(Ar-C), 126.5(Ar-C), 120.2(C-13), 114.7(C-17), 114.4(Ar-C), 80.9(C-6), 66.6(C-14),
3.5(C-5), 63.1(Ar-CH
2
CH
3
), 59.8(C-4), 42.5(C-7), 36.5(C-3), 25.7(C-8), 24.4(C-9), 23.7(C-2),
+
7.8(C-5), 14.6(Ar-CH
2
CH
3
). HRMS (ESI) calcd for C26
H34NO
6
[M+NH
4
] 456.2381, found
56.2390.
4
.1.2.23
((1aR,7aS,10aS,10bS,E)-1a-Methyl-8-methylene-9-oxo-1a,2,3,6,7,7a,8,9,10a,10b-
(E)-3-(4-
decahydrooxireno[2',3':9,10]cyclodeca[1,2-b]furan-5-yl)methyl
1
acetoxyphenyl)acrylate(4v): White solid (yield: 78% ), mp 81-83 ℃ . H NMR (400 MHz, CDCl )
3
δ 7.63 (d, J = 16.0 Hz, 1H, H-18), 7.50 (d, J = 8.6 Hz, 2H, Ar-H), 7.10 (d, J = 8.6 Hz, 2H, Ar-H),
6
5
3
2
1
1
1
3
.35 (d, J = 16.0 Hz, 1H, H-17), 6.20 (d, J = 3.4 Hz, 1H, H-13), 5.70 (t, J = 8.2 Hz, 1H, H-1),
.53 (d, J = 3.1 Hz, 1H, H-13), 4.75 (d, J = 12.5 Hz, 1H, H-14), 4.57 (d, J = 12.5 Hz, 1H, H-14),
.84 (t, J = 9.3 Hz, 1H, H-6), 2.92 (dd, J = 14.8, 5.8 Hz, 1H, H-7), 2.85 (d, J = 9.4 Hz, 1H, H-5),
.50 – 2.09 (m, 9H, CH2, ArOCOCH
3
), 1.71 – 1.62 (m, 1H, CH
2
), 1.52 (s, 3H, H-15), 1.08 (t, J =
), 166.3(C-
1
3
2.7 Hz, 1H, CH
2
). C NMR (100 MHz, CDCl ) δ 169.3(C-12), 169.0(Ar-OCOCH
3
3
6), 152.1(Ar-C), 144.2(C-18), 138.6(C-11), 134.8(C-10), 131.6(Ar-C), 130.5(C-1), 129.1(Ar-C),
22.1(Ar-C), 120.2(C-13), 117.4(C-17), 80.9(C-6), 66.7(C-14), 63.1(C-5), 59.8(C-4), 42.5(C-7),
6.4(C-3), 25.6(C-8), 24.3(C-9), 23.7(C-2), 21.0(Ar-OCOCH ), 17.8(C-15). HRMS (ESI) calcd
3
+
for C H NO [M+NH ] 470.2173, found 470.2171.
2
6
32
7
4
28