Synthesis of Cytotoxic Isodeoxypodophyllotoxin Analogs

Article abstract of DOI:10.1002/jhet.2618

A series of aryltetralin lignans 7a, 7b, 7c, 7d, 7e, 7f, 7g, 7h, 7i, 7j, 7k, 7l were synthesized as cytotoxic isodeoxypodophyllotoxin analogs. The title compounds 7a, 7b, 7c, 7d, 7e, 7f, 7g, 7h, 7i, 7j, 7k, 7l were synthesized from the reaction of (+)-(R)-4-[benzo(d)(1,3)dioxol-5-ylmethyl]-dihydrofuran-2-(3H)-one with different arylaldehydes to afford benzyl alcohol analogs and subsequent cyclization with trifluoroacetic acid in dichromethane. The preliminary screening of the compounds against viability of blood cancer human cell line K562 revealed that compounds 7d, 7e, and 7f had higher inhibitory activity at 10 μg/mL concentration compared with etoposide as reference drug.

Full text of DOI:10.1002/jhet.2618

Month 2016
Synthesis of Cytotoxic Isodeoxypodophyllotoxin Analogs
a
b
c
d
d
*
Babak Heidary Alizadeh, Saeed Emami, Gholamreza Dehghan, Alireza Foroumadi, and Abbas Shafiee
aIranian Research Institute of Plant Protection (IRIPP), Shahid Chamran Avenue, Yaman St. No 1;
P.O. Box: 1454, Tehran, Iran
bDepartment of Medicinal Chemistry and Pharmaceutical Sciences Research Center, Faculty of Pharmacy,
Mazandaran University of Medical Sciences, Sari, Iran
cDepartment of Biology, Faculty of Natural Sciences, University of Tabriz, Tabriz, Iran
dDepartment of Medicinal Chemistry, Faculty of Pharmacy and Pharmaceutical Sciences Research Center,
Tehran University of Medical Sciences, Tehran, Iran
*
E-mail: shafieea@tums.ac.ir
Received October 31, 2015
DOI 10.1002/jhet.2618
Published online 00 Month 2016 in Wiley Online Library (wileyonlinelibrary.com).
A series of aryltetralin lignans 7a–l were synthesized as cytotoxic isodeoxypodophyllotoxin analogs. The
title compounds 7a–l were synthesized from the reaction of (+)-(R)-4-[benzo(d)(1,3)dioxol-5-ylmethyl]-
dihydrofuran-2-(3H)-one with different arylaldehydes to afford benzyl alcohol analogs and subsequent
cyclization with trifluoroacetic acid in dichromethane. The preliminary screening of the compounds against
viability of blood cancer human cell line K562 revealed that compounds 7d, 7e, and 7f had higher inhibitory
activity at 10 μg/mL concentration compared with etoposide as reference drug.
J. Heterocyclic Chem., 00, 00 (2016).
INTRODUCTION
protein at the colchicine binding site, the semi-synthetic
analogs such as etoposide inhibit DNA topoisomerase II,
leading to blockade in the late S stage of the cell cycle [9].
Subsequently, the substantial interest has been focused on
the 4-deoxy analog of podophyllotoxin (5), which
was isolated from the root of Anthriscus sylvestris.
4-Deoxypodophyllotoxin (5) exhibited potent anticancer
activity against various cell lines [10,11]. Further studies
indicated that 4-deoxypodophyllotoxin (5) inhibits tubulin
polymerization and also induces cell cycle arrest at G2/M
through activation of caspase-3 and caspase-7, and upregula-
tion of p53 and Bax [12,13]. Moreover, it was reported that
4′-demethyl-4-deoxypodophyllotoxin (6) had a comparable
in vitro potency respect to 4-deoxypodophyllotoxin (5).
However, the antitumor activity of 4′-demethyl-4-
deoxypodophyllotoxin (6) in the BDF1/3LL model was
substantially less than that of 4-deoxypodophyllotoxin
(5) [14].
The structure activity relationship studies of
podophyllotoxin and its analogs demonstrated that the integ-
rity of rings A, B, and D is necessary for maintaining the an-
ticancer activity, while rings C and E are suitable portions of
the molecules for structural modifications. The investiga-
tions on the stereochemistry of podophyllotoxin family
revealed that the 5a,8a-trans configuration is important for
high cytotoxic activity [15]. Interestingly, Zavala et al.
have reported that isodeoxypodophyllotoxin (7a) with
5,5a-trans-5a,8a-trans configuration has equipotent inhibi-
tion against microtubule assembly in comparison to
Cancer is a wide group of diseases which can be trig-
gered by environmental pollutants and genetic mutations,
involving unregulated cell growth and division [1]. There
are over 200 different known cancers that affect most areas
of the body in humans [2]. Cancers figure among the lead-
ing causes of human death, and the number of people liv-
ing beyond a cancer diagnosis reached nearly 14.5
million in 2014 [3]. Chemotherapy is an important option
for treatment of patients with cancer, but prolonged treat-
ment with chemotherapeutic agents can result in multidrug
resistance. Furthermore, almost all the chemotherapeutic
agents have severe side effects on normal tissues [4]. To
overcome drug resistance and toxicity, development of
new anticancer agents with better selectivity is an urgent
need in medicinal chemistry [5].
A number of nonalkaloid toxin lignins such as
podophyllotoxin (1; Fig. 1) have been isolated from plants
and used as a potential lead molecule to yield analogs
endowed with higher potency, lower toxicity, and better
physicochemical properties [6]. For example, several clin-
ically valuable anticancer drugs, such as etoposide (2,
VP-16), etoposide phosphate (3), and teniposide (4, VM-
26) have been derived from podophyllotoxin (1) and are
currently in clinical use for the treatment of small cell lung
cancer, testicular carcinoma, non-Hodgkin’s lymphoma,
and Kaposi’s sarcoma [7,8]. While podophyllotoxin in-
hibits tubulin polymerization through interaction with the
© 2016 Wiley Periodicals, Inc.

B. H. Alizadeh, S. Emami, G. Dehghan, A. Foroumadi, and A. Shafiee
Vol 000
Figure 1. Structures of podophyllotoxins 1–4, deoxypodophyllotoxins 5 and 6, and isodeoxypodophyllotoxins 7a–l. It should be noted that the atom
numbering is based on the furo[3′,4′:6,7]naphtho[2,3-d][1,3]dioxol-6-one structure. [Color figure can be viewed in the online issue, which is available
at wileyonlinelibrary.com.]
Scheme 1. Synthesis of isodeoxypodophyllotoxin analogs 7a–l. [Color figure can be viewed in the online issue, which is available at wileyonlinelibrary.com.]
podophyllotoxin (bearing a 5,5a-cis-5a,8a-trans configura-
tion) [16]. In continuation of our work on heterocyclic
compounds [17–23], we describe here the synthesis and cy-
totoxic activity of isodeoxypodophyllotoxin derivatives with
focusing on the modification of E ring (Fig. 1).
deoxypodophyllotoxin
(5)
was
prepared
from
podophyllotoxin (1) by catalytic hydrogenolysis in the
presence of 10% palladium/carbon [25]. In the present
report, the synthesis of target compounds 7a–l was
performed according to the route illustrated in Scheme 1.
The reaction of optically pure (R)-4-(3,4-methylenebenzyl)
dihydrofuran-2(3H)-one (8) with various aromatic
aldehydes in the presence of LDA at À78°C afforded
benzyl alcohol analogs 9a-l. The aldol products 9a–l were
mixture of two syn/anti diasteromers based on the S or R
configuration of benzylic hydroxyl group [17]. Treatment of
compounds 9a–l with trifluoroacetic acid in dichromethane
RESULTS AND DISCUSSIONS
Chemistry. Previously, Hanessian and Ninkovic have
reported the synthesis of isodeoxypodophyllotoxin (7a),
by using trimethylstannyl radical addition to a dienic
system for the construction of the dibenzylbutyrolactone
motif as well as the aryltetralin unit [24]. Furthermore,
resulted
in
ring
closure
and
formation
of
isodeoxypodophyllotoxin derivatives 7a–l. The 5,5a-trans-
Journal of Heterocyclic Chemistry
DOI 10.1002/jhet

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Isodeoxypodophyllotoxin Analogs
5a,8a-trans stereochemistry of compounds 7a–l was
confirmed by vicinal coupling of protons at the 5, 5a, and 8a
positions. As illustrated in Figure 2, the H-5 protons of
compounds 7a–l appeared at 4.05–4.07ppm as doublet with
large coupling constants of 10.0–11.5ppm. Also, the J5a,8a
values of compounds 7a–l were 13.0–13.8ppm.
time of incubation 72h. The obtained growth inhibition
values at 10 μg/mL revealed that compounds 7d, 7e, and
7f had higher inhibitory activity compared with
etoposide. The maximum growth inhibition (87%) was
observed with 4-methoxy analog 7e at 50 μg/mL
concentration, after 72 h incubation. The comparison of
the growth inhibition values of unsubstituted compound
7b and methoxy substituted derivatives 7c–e
demonstrated that the 3- or 4-methoxy substituent can
improve the cytotxic activity. Furthermore, the 3,4-
dimethoxy analog 7f showed better inhibition compared
with unsubstituted compound 7b. Interestingly, the
inhibitory activity of compounds 7d–f was more than that
of isodeoxypodophyllotoxin (7a). These finding showed
that the 3,4,5-trimethoxy entity is not essential for
activity. However, the presence of one or two methoxy
groups at 3 and/or 4 positions can increase the activity.
Other patterns of methoxy substituents were not favorable
for activity, as observed with 7g–j respect to the 3,4-
dimethoxy analog 7f.
Cytotoxic activity.
Primarily, the in vitro cytotoxic
activity of the synthesized isodeoxypodophyllotoxin
analogs 7a–l were evaluated against blood cancer human
cell line K562 at the concentrations of 10 and 50 μg/mL,
in comparison to etoposide as reference drug. The growth
inhibition values (%) of the compounds 7a–l after 48 and
72 h incubation were listed in Table 1. As seen in Table
1, the percentages of inhibition for tested compounds at
10 μg/mL were in the range of 36–80% after maximum
CONCLUSIONS
We have synthesized a series of cytotoxic aryltetralin
lignans, namely, isodeoxypodophyllotoxin analogs 7a–l,
starting from (+)-(R)-4-[benzo(d)(1,3)dioxol-5-ylmethyl]-
dihydrofuran-2-(3H)-one. The reaction of the latter compound
Figure 2. The 5,5a-trans-5a,8a-trans stereochemistry of compounds
7a–l, confirmed by vicinal coupling of protons at the 5, 5a, and 8a posi-
tions. [Color figure can be viewed in the online issue, which is available
at wileyonlinelibrary.com.]
Table 1
The percentages of growth inhibition of the compounds 7a–l against human blood cancer cell line K562 at the concentrations of 10 and 50 μg/mL after 48
and 72 h incubation.
48 h
72 h
Compound
R
10 μg/mL
35 2.7
50 μg/mL
43 4.2
10 μg/mL
48 3.5
50 μg/mL
46 4.2
7a
7b
7c
7d
7e
7f
7g
7h
7i
7j
7k
7l
3,4,5-tri-MeO
H
22 1.5
33 3.4
64 4.8
70 5.9
74 8.3
58 4.8
42 3.6
35 3.2
36 4.1
34 4.1
68 5.3
45.3 6.7
41 3.7
39 3.2
70 5.7
57 6.1
74 5.7
28 1.8
51 6.3
36 2.5
40 2.8
69 5.3
47 3.9
NDa
48 4.3
46 3.6
80 6.7
75 6.6
72 4.6
38 3.1
66 7.1
52 4.8
36 1.9
50 4.5
62 4.8
68 8.3
53 4.3
56 5.3
77 8.2
87 6.6
62 4.6
41 3.7
68 5.8
43 3.4
61 4.9
46 4.8
58 5.1
ND
2-MeO
3-MeO
4-MeO
3,4-di-MeO
2,4-di-MeO
2,3-di-MeO
2,5-di-MeO
2,6-di-MeO
3,5-di-MeO, 4-OH
3,4-O-CH2-O
Etoposide
aNot determined.
Journal of Heterocyclic Chemistry
DOI 10.1002/jhet

B. H. Alizadeh, S. Emami, G. Dehghan, A. Foroumadi, and A. Shafiee
Vol 000
with different arylaldehydes afforded syn/anti diasteromers of
(3S,4R)-4-[benzo(d)(1,3)dioxol-5-ylmethyl]-3-[hydroxy(4-
H-6), 2.09 (dd, J=3.6Hz, J=13.8Hz, H-6), 2.18 (dd,
J=6.4Hz, J=13.8Hz, H-6), 2.30 (dd, J=9.0Hz,
J=13.8Hz, H-6), 2.44 (m, –H4), 2.61 (t, J=7.4Hz, H-3),
2.65 (dd, J=3.1Hz, J=7.4Hz, H-3), 2.85 (m, H-4), 3.89
anti (t, J=9.1Hz, H-5), 3.93 syn (t, J=8.6Hz, H-5), 4.12
anti (t, J=8.5Hz, H-5), 4.89 anti (d, J=8.3Hz, H-7), 5.41
syn (s, J=2.0Hz, H-7), 5.92 and 5.96 (2s, 2H, OCH2O),
6.29–6.33 (m, 2H, Ar), 6.63 (m, 1H, Ar), 7.30–7.45 (m,
5H, Ph). FT-IR (film) νmax: 3450, (OH), 1780 (C=O)
cmÀ1. ESI-Mass m/z: 349 [M+Na]+. Anal. Calcd for
C19H18O5: C, 69.93; H, 5.56. Found: C, 69.76; H, 5.49.
(3S,4R)-4-[Benzo(d)(1,3)dioxol-5-ylmethyl]-3-[hydroxy(2-
methoxyphenyl)methyl]-dihydrofuran-2(3H)-one (9c). Yield
methoxyphenyl)methyl]-dihydrofuran-2(3H)-ones,
which
were treated with trifluoroacetic acid to give desired
isodeoxypodophyllotoxin analogs 7a–l. The cytotoxic activ-
ity of the compounds against blood cancer human cell line
K562 demonstrated that 3-methoxy, 4-methoxy and 3,4-
dimethoxy derivatives (compounds 7d, 7e, and 7f, respec-
tively) had higher inhibitons at 10 μg/mL concentration re-
spect to the reference drug etoposide.
EXPERIMENTAL
1
75% as a mixture of diasteromers (anti/syn: 55/45); H
Chemistry.
The required chemicals and reagents
were obtained from Merck and Sigma-Aldrich. The
starting material (+)-(R)-4-[benzo(d)(1,3)dioxol-5-
NMR (500MHz, CDCl3) δ: 2.06 (dd, J=4.9Hz,
J=13.8Hz, H-6), 2.18 (dd, J=9.9Hz, J=13.8Hz, H-6),
2.27 (dd, J=6.9Hz, J=13.7Hz, H-6), 2.38 (dd, J=8.7Hz,
J=13.7Hz, H-6), 2.47 (m, H-4), 2.62 (dd, J=8.3Hz,
J=9.3Hz, H-3), 2.66 (dd, J=2.9Hz, J=6.8Hz, H-3), 2.90
(m, H-4), 3.79 (s, –OMe), 3.88 (s, –OMe), 3.89 anti (m,
H-5), 3.99 syn (m, J=6.3Hz, J=7.9Hz, H-5), 4.14 anti (t,
J=6.9Hz, H-5), 4.46 syn (t, J=7.9Hz, H-5), 4.85 anti (d,
J=11.2Hz, H-7), 5.22 syn (s, J=5.7Hz, H-7), 5.90 and
5.91 (2s, 2H, OCH2O), 6.27–6.34 (m, 2H, Ar), 6.61 (d,
J= 7.8 Hz, Ar), 6.66 (d, J=8.4Hz, Ar), 6.82–6.99 (m, Ph),
7.25–7.34 (m, Ph). FT-IR (film) νmax: 3447 (OH), 1763
(lactone) cmÀ1. ESI-Mass m/z: 379 [M+Na]+. Anal. Calcd
for C20H20O6: C, 67.41; H, 5.66. Found: C, 67.65; H, 5.42.
(3S,4R)-4-[Benzo(d)(1,3)dioxol-5-ylmethyl]-3-[hydroxy(3,4-
dimethoxyphenyl)methyl]-dihydrofuran-2(3H)-one (9f). FT-
IR (film) νmax: 3450, (OH), 1780 (C=O) cmÀ1. ESI-Mass
m/z: 409 [M +Na]+. Anal. Calcd for C21H22O7: C, 67.41;
H, 5.66. Found: C, 67.65; H, 5.42.
ylmethyl]-dihydrofuran-2-(3H)-one (8) was prepared
according to the reported method [17]. The purity of all
compounds was confirmed by thin-layer chromatography
1
(TLC) using various solvents with different polarities. H
NMR spectra were recorded using
spectrometer (Brucker, Rheinstetten, Germany), and
chemical shifts are expressed as (ppm) with
tetramethylsilane as internal standard. The IR spectra were
taken using Shimadzu IR prestige-21 spectrometer. Mass
spectra were recorded on Agilent 6410 Triple Quad.
LC/MS. The elemental analysis was performed with an
Elementar Analysensystem GmbH VarioEL CHNS mode,
which were within 0.4% of theoretical values for C, H,
and N.
a Bruker 500
δ
General procedure for the synthesis of (3S,4R)-4-[benzo(d)
(1,3)dioxol-5-ylmethyl]-3-(hydroxy(aryl)methyl)-dihydrofuran-
2(3H)-one derivatives 9a–l.
A solution of compound 8
(3S,4R)-4-[Benzo(d)(1,3)dioxol-5-ylmethyl]-3-[hydroxy(2,4-
(70mg, 0.3mmol) in dry THF (0.5mL) was added to a
solution of LDA (0.4mL, 0.6mmol) in THF (3mL) at
À78°C and stirred for 30min. To this, solution was added
appropriate aldehyde (0.36mmol) and HMPA (0.1mL,
0.6mmol) and the mixture was stirred for 2h, then
quenched with saturated aq. NH4Cl (2mL). The mixture
was extracted with EtOAc (3×20mL). The extract was
washed successively with water (3mL), 10% HCl (2mL),
water, saturated aq. NaHCO3 and NaCl. Organic phase
was dried (Na2SO4), filtered and evaporated in vacuo to
give a viscous oil. The residue was purified by TLC
chromatography (silica gel, hexane/EtOAc, 5:1) to give
compounds 9a–l as mixture of diasteromers (anti/syn).
Compounds 9a, 9d, and 9e were reported in the litera-
ture [17], and physicochemical and spectroscopic data of
remaining compounds were described here:
dimethoxyphenyl)methyl]-dihydrofuran-2(3H)-one (9g). Yield
70% as a mixture of diasteromers (anti/syn: 54/46); H
1
NMR (500MHz, CDCl3) δ: 2.06–2.38 (m, 2H, –CH2),
2.54–2.82 (m, 2H, –CH2), 2.01 (dd, J=4.9Hz, J=13.8Hz,
H-6), 2.16 (dd, J=9.9Hz, J=13.8Hz, H-6), 2.22 (dd,
J=6.9Hz, J=13.7Hz, H-6), 2.37 (dd, J=8.7Hz,
J=13.7Hz, H-6), 2.47 (m, H-4), 2.92 (dd, J=8.3Hz,
J=9.3Hz, H-3), 3.08 (dd, J=5.0Hz, J=15.3Hz, H-3),
3.17 (m, H-4), 3.74 (s, –OMe), 3.80 (s, –OMe), 3.91 (s,
–OMe), 3.98 anti (m, J=9.0Hz, H-5), 4.13 syn (dd,
J=7.25Hz, J=14.4Hz, H-5), 4.46 anti (t, J=8.0Hz, H-5),
4.512 syn (m, H-7), 4.72 anti (d, J=8.6Hz, H-7), 5.09 syn
(s, J=5.6Hz, H-7), 5.86 (s, 2H, OCH2O), 6.27–6.68 (m,
3H, aromatic H), 7.33 (d, 1H, J=5.7Hz, aromatic). FT-IR
(film) νmax: 3460, (OH), 1770 (C=O) cmÀ1. ESI-Mass m/z:
409 [M+Na]+. Anal. Calcd for C21H22O7: C, 67.41; H,
5.66. Found: C, 67.55; H, 5.72.
(3S,4R)-4-[Benzo(d)(1,3)dioxol-5-ylmethyl]-3-[hydroxy(phenyl)
methyl]-dihydrofuran-2(3H)-one (9b).
Yield 74% as a
(3S,4R)-4-[Benzo(d)(1,3)dioxol-5-ylmethyl]-3-[hydroxy(2,3-
dimethoxyphenyl)methyl]-dihydrofuran-2(3H)-one (9h). Yield
65% as a mixture of diasteromers (anti/syn: 50/50); 1H
mixture of diasteromers (anti/syn: 54/46); 1H NMR
(500 MHz, CDCl3) δ: 1.96 (dd, J= 4.8 Hz, J= 13.8Hz,
Journal of Heterocyclic Chemistry
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Isodeoxypodophyllotoxin Analogs
NMR (500MHz, CDCl3) δ: 2.01 (dd, J=3.9Hz, J=13.5Hz,
H-6), 2.08 (dd, J=5.9Hz, J= 13.5Hz, H-6), 2.22 (dd,
J=9.5Hz, J=13.5 Hz, H-6), 2.58 (dd, J=8.9Hz,
J=13.5 Hz, H-6), 2.66 and 2.82 (m, H-3), 2.93 (dd,
J=8.5 Hz, 12.7 Hz, H-3), 3.86 (s, 6H, –OMe), 3.89 (s, 3H,
–OMe), 3.98–4.22 (m, 2H, H-5), 4.81 anti (d, J=8.2Hz,
H-7), 5.62 syn (s, J= 2.7Hz, H-7), 5.91 (s, 2H, OCH2O),
5.83–7.02 (m, aromatic H). FT-IR (film) νmax: 3550, (OH),
1775 (C=O) cmÀ1. ESI-Mass m/z: 409 [M + Na]+. Anal. Calcd
for C21H22O7: C, 67.41; H, 5.66. Found: C, 67.56; H, 5.65.
(3S,4R)-4-[Benzo(d)(1,3)dioxol-5-ylmethyl]-3-[hydroxy(2,5-
dimethoxyphenyl)methyl]-dihydrofuran-2(3H)-one (9i). Yield
the resulting residue was purified by flash column
chromatography (silica gel, hexane/EtOAc, 3:1) to give
compound 7f (25 mg, yield 95%).
5-(3,4,5-Trimethoxy-phenyl)-5,8,8a,9-tetrahydro-5aH-furo
[3′,4′:6,7]naphtho[2,3-d][1,3]dioxol-6-one (7a). Yield 85%;
1
mp 249–254°C; H NMR (500MHz, CDCl3) δ: 2.49 (dd,
1H, J= 10.9Hz, J= 13.7 Hz , 5a-H), 2.62 (m, 1H, 8a-H),
2.96 (m, 2H, 9-H), 3.90 (m, 9H, –OMe), 3.98 (dd, 1H,
ABX, JAB = 8.5 Hz, JBX = 10.5Hz, 8-H), 4.06 (d, 1H,
J = 10.6Hz, 5-H), 4.52 (dd, 1H, ABX, JAB =6.5 Hz,
JAX = 8.5 Hz, 8-H), 5.90 (s, 2H, OCH2O), 6.34 (s, 1H, 4-
H), 6.60 (s, 1H, 10-H), 6.61 (s, 1H, aromatic H), 6.67 (s,
1H, aromatic H). FT-IR (film) νmax: 1795 (lactone) cmÀ1
.
1
55% as a mixture of diasteromers (anti/syn: 46/54); H
ESI-Mass m/z: 399 [M + H]+, 422 [M + Na]+. Anal. Calcd
for C22H22O7: C, 66.32; H, 5.57. Found: C, 66.45; H, 5.49.
5-(Phenyl)-5,8,8a,9-tetrahydro-5aH-furo[3′,4′:6,7]naphtho
NMR (500MHz, CDCl3) δ: 2.04–2.09 (m, H-6), 2.39 (m,
H-6), 2.39 (dd, J=8.9Hz, J=13.5Hz, H-6), 2.76 and 2.97
(m, H-3), 3.79 and 3.87 (2s, 6H, -OMe), 3.97–4.47 (m,
2H, H-5), 4.80 anti (d, J=12.5Hz, H-7), 5.15 syn (s,
J=6.5Hz, H-7), 5.89 (s, 2H, OCH2O), 5.83–7.02 (m,
aromatic H). FT-IR (film) νmax: 3450, (OH), 1780 (C=O)
cmÀ1. ESI-Mass m/z: 409 [M+Na]+. Anal. Calcd for
C21H22O7: C, 67.41; H, 5.66. Found: C, 67.55; H, 5.62.
(3S,4R)-4-[Benzo(d)(1,3)dioxol-5-ylmethyl]-3-[hydroxy(2,6-
dimethoxyphenyl)methyl]-dihydrofuran-2(3H)-one (9j). Yield
57% as a mixture of diasteromers (anti/syn: 73/27); 1H
NMR (500 MHz, CDCl3) δ: 2.15–2.36 (m, H-6), 2.22 (dd,
J=6.9Hz, J=13.7 Hz, H-6), 2.37 (dd, J=8.7Hz,
J=13.7 Hz, H-6), 2.50 (m, H-4), 2.77 (dd, J=6.1Hz,
J=14.1 Hz, H-3), 2.89 (m, H-3), 2.98 (m, H-4), 3.68 (s,
–OMe), 3.83 (s, –OMe), 3.92 anti (t, J= 9.0 Hz, H-5), 3.94
syn (m, H-5), 4.13 anti (t, J=9.0 Hz, H-5), 4.47 syn (t,
J=7.4 Hz, H-7), 4.81 anti (d, J= 12.1Hz, H-7), 5.17 syn (s,
J=6.2 Hz, H-7), 5.91 and 5.92 (2 s, 2H, OCH2O), 6.24 (s,
Ar), 630 (s, Ph), 6.33 (m, Ar), 6.63 (d, J=12.5Hz, Ar), 6.85
(d, J= 12.5 Hz, Ar), FT-IR (film) νmax: 3460, (OH), 1780
(C=O) cmÀ1. ESI-Mass m/z: 409 [M +Na]+. Anal. Calcd for
C21H22O7: C, 67.41; H, 5.66. Found: C, 67.60; H, 5.26.
1
[2,3-d][1,3]dioxol-6-one (7b). Yield 60%; viscous oil; H
NMR (500 MHz, CDCl3) δ: 2.53 (dd, 1H, J= 11.5 Hz,
J = 13.5Hz, 5a-H), 2.78 (m, 1H, 8a-H), 2.97 (m, 2H, 9-
H), 3.98 (dd, 1H, ABX, JAB =8.4 Hz, JBX = 10.5Hz, 8-
H), 4.06 (d, 1H, J =11.5 Hz, 5-H), 4.52 (dd, 1H, ABX,
JAB = 6.5 Hz, JAX =8.4 Hz, 8-H), 5.87 (2 s, 2H, OCH2O),
6.32 (s, 1H, 4-H), 6.60 (s, 1H, 10-H), 6.66-7.52 (m, 5H,
Ph). FT-IR (film) νmax: 1795 (lactone) cmÀ1. ESI-Mass
m/z: 331 [M +Na]+. Anal. Calcd for C19H16O4: C, 74.01;
H, 5.23. Found: C, 74.25; H, 5.09.
5-(2-Methoxy-phenyl)-5,8,8a,9-tetrahydro-5aH-furo[3′,4′:6,7]
naphtho[2,3-d][1,3]dioxol-6-one (7c). Yield 65%; viscous
oil; 1H NMR (500MHz, CDCl3) δ: 2.57 (dd, 1H,
J = 10.5Hz, J =13.5 Hz, 5a-H), 2.69 (m, 1H, 8a-H), 2.98
(m, 2H, 9-H), 3.85 (s, 3H, –OMe), 3.94 (dd, 1H, ABX,
JAB = 7.0 Hz, JBX = 9.5 Hz, 8-H), 4.07 (d, 1H, J= 10.5 Hz,
5-H), 4.46 (dd, 1H, ABX, JAB = 6.0 Hz, JAX = 7.0Hz, 8-
H), 5.84 (2 s, 2H, OCH2O), 6.29 (s, 1H, 4-H), 6.58 (s,
1H, 10-H), 6.69-7.17 (m, 4H, aromatic H). FT-IR (film)
ν
max: 1790 (lactone) cmÀ1. ESI-Mass m/z: 361 [M+ Na]+.
Anal. Calcd for C20H18O5: C, 70.99; H, 5.36. Found: C,
71.05; H, 5.59.
(3S,4R)-4-[Benzo(d)(1,3)dioxol-5-ylmethyl]-3-[hydroxy(4-
hydroxy-3,5-dimethoxyphenyl) methyl]-dihydrofuran-2(3H)-one
(9k). FT-IR (film) νmax: 3430, (OH), 1720 (C=O) cmÀ1
.
5-(3-Methoxy-phenyl)-5,8,8a,9-tetrahydro-5aH-furo[3′,4′:6,7]
ESI-Mass m/z: 425 [M+Na]+. Anal. Calcd for C21H22O8:
C, 62.68; H, 5.51. Found: C, 62.53; H, 5.36.
naphtho[2,3-d][1,3]dioxol-6-one (7d).
Yield 55%; viscous
oil; 1H NMR (500MHz, CDCl3) δ: 2.38 (dd, 1H,
J=10.0Hz, J=13.8Hz, 5a-H), 2.48 (m, 1H, 8a-H), 2.89
(m, 2H, 9-H), 3.80 (s, 3H, –OMe), 3.97 (dd, 1H, ABX,
JAB =8.6Hz, JBX =11.8Hz, 8-H), 4.06 (d, 1H, J=10.0Hz,
5-H), 4.36 (dd, 1H, ABX, JAB =6.3Hz, JAX =8.7Hz, 8-H),
5.88 (s, 2H, OCH2O), 6.25 (s, 1H, 4-H), 6.66 (s, 1H, 8-H),
6.73–7.36 (m, 3H, aromatic H). FT-IR (film) νmax: 1795
(lactone) cmÀ1. ESI-Mass m/z: 361 [M+Na]+. Anal. Calcd
for C20H18O5: C, 70.99; H, 5.36. Found: C, 70.75; H, 5.21.
5-(4-Methoxy-phenyl)-5,8,8a,9-tetrahydro-5aH-furo[3′,4′:6,7]
naphtho[2,3-d][1,3]dioxol-6-one (7e). Yield 90%; mp 228–
232°C; 1H NMR (500MHz, CDCl3) δ: 2.51 (dd, 1H,
J=11.0Hz, J=13.5Hz, 5a-H), 2.60 (m, 1H, 8a-H), 2.96
(m, 2H, 9-H), 3.80 (s, 3H, –OMe), 3.97 (dd, 1H, ABX,
3-[Benzo(1,3)dioxol-5-yl-hydroxy-methyl]-4-benzo[1,3]dioxol-
5-ylmethyl-dihydro-furan-2-one (9l).
FT-IR (film) νmax:
3450, (OH), 1750 (C=O) cmÀ1. ESI-Mass m/z: 393 [M
+Na]+. Anal. Calcd for C20H18O7: C, 64.86; H, 4.90.
Found: C, 64.65; H, 4.96.
Typical procedure for the synthesis of compounds 7a–l:
synthesis of compound 7f. To a solution of compound 9f
(30 mg, 0.077 mmol) in CH2Cl2 (0.5 mL), CF3COOH
(0.3 mL) was added, and the solution was stirred at room
temperature overnight. After removing the excess of
CF3COOH by air flow under hood, the crude product
was washed with saturated aq. NaCO3 and extracted with
CH2Cl2 and dried (MgSO4). After evaporation of solvent,
Journal of Heterocyclic Chemistry
DOI 10.1002/jhet

B. H. Alizadeh, S. Emami, G. Dehghan, A. Foroumadi, and A. Shafiee
Vol 000
JAB =8.5Hz, JBX =10.5Hz, 8-H), 4.07 (d, 1H, J=11.0Hz,
5-H), 4.51 (dd, 1H, ABX, JAB =7.0Hz, JAX =8.5Hz, 8-
H), 5.87 (2s, 2H, OCH2O), 6.29 (s, 1H, 4-H), 6.59 (s, 1H,
10-H), 6.87 (d, 2H, J=9.0Hz, aromatic H), 7.12 (d, 2H,
J=9.0Hz, aromatic H). FT-IR (film) νmax: 1795 (lactone)
cmÀ1. ESI-Mass m/z: 361 [M+Na]+. Anal. Calcd for
C20H18O5: C, 70.99; H, 5.36. Found: C, 70.85; H, 5.59.
5-(3,4-Dimethoxy-phenyl)-5,8,8a,9-tetrahydro-5aH-furo[3′,4′:
(d, 1H, J=7.5Hz, aromatic H). FT-IR (film) νmax: 1795
(lactone) cmÀ1. ESI-Mass m/z: 391 [M+Na]+. Anal. Calcd
for C21H20O6: C, 68.47; H, 5.47. Found: C, 68.52; H, 5.29.
5-(2,6-Dimethoxy-phenyl)-5,8,8a,9-tetrahydro-5aH-furo[3′,4′:
6,7]naphtho[2,3-d][1,3]dioxol-6-one (7j).
Yield 54%;
1
viscous oil; H NMR (500MHz, CDCl3) δ: 2.55 (dd, 1H,
J=11.5Hz, J=13.0Hz, 5a-H), 2.61 (m, 1H, 8a-H), 2.91
(m, 2H, 9-H), 3.77 (2s, 6H, –OMe), 3.97 (dd, 1H, ABX,
JAB =8.5Hz, JBX =11.5Hz, 8-H), 4.05 (d, 1H, J=11.5Hz,
5-H), 4.54 (dd, 1H, ABX, JAB =7.0Hz, JAX =8.5Hz, 8-
H), 5.85 (2s, 2H, OCH2O), 6.42 (s, 1H, 4-H), 6.51–6.92
(m, 3H, aromatic H). FT-IR (film) νmax: 1795 (lactone)
cmÀ1. ESI-Mass m/z: 391 [M+Na]+. Anal. Calcd for
C21H20O6: C, 68.47; H, 5.47. Found: C, 68.52; H, 5.34.
6,7]naphtho[2,3-d][1,3]dioxol-6-one (7f).
Yield 95%; mp
1
220–225°C; H NMR (500MHz, CDCl3) δ: 2.50 (dd, 1H,
J=11.2Hz, J=13.6Hz, 5a-H), 2.61 (m, 1H, 8a-H), 2.95
(m, 2H, 9-H), 3.85 and 3.88 (2s, 6H. –OMe), 3.98 (dd,
1H, ABX, JAB =8.9Hz, JBX =10.5Hz, 8-H), 4.06 (d, 1H,
J=11.1Hz, 5-H), 4.52 (dd, 1H, ABX, JAB =6.8Hz,
JAX =8.4Hz, 8-H), 5.89 (2s, 2H, OCH2O), 6.34 (s, 1H, 4-
H), 6.60 (s, 1H, 10-H), 6.78 (s, 1H, Ph-H), 6.81 (d, 1H,
J=8.2Hz, Ph-H), 6.85 (d, 1H, J=8.2Hz, Ph-H). FT-IR
(film) νmax: 1790 (lactone) cmÀ1. ESI-Mass m/z: 391 [M
+Na]+. Anal. Calcd for C21H20O6: C, 68.47; H, 5.47.
Found: C, 68.32; H, 5.59.
5-(4-Hydroxy-3,5-dimethoxy-phenyl)-5,8,8a,9-tetrahydro-5aH-
furo[3′,4′:6,7]naphtho[2,3-d][1,3]dioxol-6-one (7k).
Yield
80%; mp 240–246°C; 1H NMR (500MHz, CDCl3) δ: 2.49
(dd, 1H, J= 11.1 Hz, J=13.8Hz, 5a-H), 2.62 (m, 1H, 8a-
H), 2.96 (m, 2H, 9-H), 3.99 (m, 6H, –OMe), 4.02 (dd, 1H,
ABX, JAB =8.6Hz, JBX =11.1Hz, 8-H), 4.05 (d, 1H,
J=11.1Hz, 5-H), 4.52 (dd, 1H, ABX, JAB =6.6Hz,
JAX =8.6Hz, 8-H), 5.88 (2s, 2H, OCH2O), 6.35 (s, 1H, 4-
H), 6.63 (s, 2H, aromatic H), 6.66 (s, 1H, 10-H). FT-IR
(film) νmax: 1790 (lactone) cmÀ1. ESI-Mass m/z: 407 [M
+Na]+. Anal. Calcd for C21H20O7: C, 65.62; H, 5.24.
Found: C, 65.40; H, 5.39.
5-(2,4-Dimethoxy-phenyl)-5,8,8a,9-tetrahydro-5aH-furo[3′,4′:
6,7]naphtho[2,3-d][1,3]dioxol-6-one (7g).
Yield 70%;
viscous oil; 1H NMR (500 MHz, CDCl3) δ: 2.53 (dd,
1H, J = 11.0 Hz, J = 13.5 Hz, 5a-H), 2.68 (m, 1H, 8a-H),
2.96 (m, 2H, 9-H), 3.81 (s, 6H, –OMe), 3.95 (dd, 1H,
ABX, JAB = 8.9 Hz, JBX = 10.5 Hz, 8-H), 4.06 (d, 1H,
J = 11.0 Hz, 5-H), 4.50 (dd, 1H, ABX, JAB = 6.5Hz,
JAX = 8.9 Hz, 8-H), 5.85 (2 s, 2H, OCH2O), 6.25 (s, 1H,
4-H), 6.29 (dd, 1H, J = 2.5 Hz, J = 8.5 Hz, Ph-H), 6.47
(d, 1H, J = 2.5 Hz, Ph-H), 6.57 (s, 1H, 10-H), 6.60 (d,
1H, J = 8.2 Hz, Ph-H). FT-IR (film) νmax: 1795 (lactone)
cmÀ1. ESI-Mass m/z: 391 [M + Na]+. Anal. Calcd for
C21H20O6: C, 68.47; H, 5.47. Found: C, 68.52; H, 5.29.
5-[Benzo(1,3)dioxol-5-yl]-5,8,8a,9-tetrahydro-5aH-furo[3′,4′:
6,7]naphtho[2,3-d][1,3]dioxol-6-one (7l).
Yield 89%; mp
1
250–256°C; H NMR (500MHz, CDCl3) δ: 2.50 (dd, 1H,
J=11.1Hz, J=13.6Hz, 5a-H), 2.60 (m, 1H, 8a-H), 2.95
(m, 2H, 9H), 3.98 (dd, 1H, ABX, JAB =8.9Hz,
JBX =10.5Hz, 8-H), 4.06 (d, 1H, J=11.1Hz, 5-H), 4.52
(dd, 1H, ABX, JAB =6.8Hz, JAX =8.4Hz, 8-H), 5.89 (s,
2H, OCH2O), 5.95 (s, 2H, OCH2O), 6.30 (s, 1H, 4-H),
6.60 (s, 2H, 10-H), 6.78 (s, 2H, aromatic H). FT-IR (film)
5-(2,3-Dimethoxy-phenyl)-5,8,8a,9-tetrahydro-5aH-furo
[3′,4′:6,7]naphtho[2,3-d][1,3]dioxol-6-one (7h). Yield 64%;
ν
max: 1795 (lactone) cmÀ1. ESI-Mass m/z: 375 [M+Na]+.
1
viscous oil; H NMR (500 MHz, CDCl3) δ: 2.55 (dd, 1H,
Anal. Calcd for C20H16O6: C, 68.18; H, 4.58. Found: C,
68.32; H, 4.50.
J =10.4 Hz, J= 13.5 Hz, 5a-H), 2.60 (m, 1H, 8a-H), 3.06
(m, 2H, 9-H), 3.77 (2 s, 6H, –OMe), 3.98 (dd, 1H, ABX,
JAB = 8.5Hz, JBX = 10.5Hz, 8-H), 4.05 (d, 1H,
J =10.4 Hz, 5-H), 4.55 (dd, 1H, ABX, JAB = 6.0 Hz,
JAX = 8.5Hz, 8-H), 5.82 (2 s, 2H, OCH2O), 6.23 (s, 1H,
4-H), 6.45 (s, 1H, 10-H), 6.51–6.90 (m, 3H, aromatic H).
FT-IR (film) νmax: 1796 (lactone) cmÀ1. ESI-Mass m/z:
391 [M + Na]+. Anal. Calcd for C21H20O6: C, 68.47; H,
5.47. Found: C, 68.32; H, 5.59.
5-(2,5-Dimethoxy-phenyl)-5,8,8a,9-tetrahydro-5aH-furo[3′,4′:
6,7]naphtho[2,3-d][1,3]dioxol-6-one (7i). Yield 61%; viscous
oil; 1H NMR (500MHz, CDCl3) δ: 2.55 (dd, 1H, J=11.0Hz,
J=13.0Hz, 5a-H), 2.72 (m, 1H, 8a-H), 2.97 (m, 2H, 9-H),
3.68 (s, 6H, –OMe), 3.95 (dd, 1H, ABX, JAB =8.4Hz,
JBX =11.5Hz, 8-H), 4.06 (d, 1H, J=11.0Hz, 5-H), 4.50
(dd, 1H, ABX, JAB =7.0Hz, JAX =8.4Hz, 8-H), 5.85 (2s,
2H, OCH2O), 6.24 (s, 1H, 4-H), 6.29 (s, 1H, aromatic H),
6.57 (s, 1H, 10-H), 6.61 (dd, 1H, J= 7.5 Hz, Ph-H), 6.86
Biology. Reagents and chemicals. RPMI 1640 and fetal
bovine serum (FBS) were purchased from Gibco BRL
(Grand Island, NY). 3-(4,5-Dimethylthiazol-2-yl)-2,5-
diphenyltetrazolium bromide (MTT), trypsin–EDTA
solution and dimethyl sulphoxide (DMSO) were
obtained from Sigma (Saint Louis, MO, USA).
Penicillin/streptomycin was purchased from Invitrogen
(San Diego, CA, USA).
Cell lines and cell culture. Human blood cancer cell line
K562 was obtained from the National Cell Bank of Iran,
Pasteur Institute, Tehran, Iran, and cultured at a density
of 3–5 × 104/mL RPMI 1640 medium supplemented
with FBS (10%, v/v), streptomycin (100 μg/mL), and
penicillin (100 U/mL) and kept at 37°C in a 5% CO2
humidified atmosphere. Drug treatments were usually
performed 24h after seeding the cells.
Journal of Heterocyclic Chemistry
DOI 10.1002/jhet

Month 2016
Isodeoxypodophyllotoxin Analogs
[6] Wang, C. Y.; Bai, X. Y.; Wang, C. H. Am J Chin Med 2014,
42, 543.
[7] Kamal, A.; Ali Hussaini, S. M.; Rahim, A.; Riyaz, S. Expert
Opin Ther Pat 2015, 25, 1025.
Cytotoxicity assay. The in vitro cytotoxic activity of all
synthesized compounds was determined against human
blood cancer cell line K562 using MTT colorimetric
assay [26]. Exponentially growing cells (4 ×104 cells/
well) were seeded in 96 well plates in RPMI with 10%
FBS and incubated for 24 h. After treatment of cells with
different concentrations of test compounds for 48 and
72h at 37°C, the medium was removed and phenol red-
free medium with FBS was added to cells. Then, MTT
solution was added to each well (2 mg/mL) and incubated
for 4 h. The viable cell number is directly proportional to
the formation of formazan. After that, the formed
formazan dye in each well was dissolved in isopropyl
alcohol and the absorbance was measured using a
microplate reader at 492nm. In each plate, there were
control wells (cells without test compounds) and blank
wells (the medium with 0.1% DMSO). The percentage of
cell viability versus control was assessed by the formula
[1 À(absorbance of treated cells/absorbance of control
cells)] ×100.
[8] You, Y. Curr Pharm Des 2005, 11, 1695.
[9] Gordaliza, M. Clin Transl Oncol 2007, 9, 767.
[10] Khaled, M.; Jiang, Z. Z.; Zhang, L. Y. J Ethnopharmacol 2013,
149, 24.
[11] Muto, N.; Tomokuni, T.; Haramoto, M.; Tatemoto, H.;
Nakanishi, T.; Inatomi, Y.; Murata, H.; Inada, A. Biosci Biotechnol
Biochem 2008, 72, 477.
[12] Shin, S. Y.; Yong, Y.; Kim, C. G.; Lee, Y. H.; Lim, Y. Cancer
Lett 2010, 287, 231.
[13] Yong, Y.; Shin, S. Y.; Lee, Y. H.; Lim, Y. Bioorg Med Chem
Lett 2009, 19, 4367.
[14] Terada, T.; Fujimoto, K.; Nomura, M.; Yamashita, J.;
Kobunai, T.; Takeda, S.; Wierzba, K.; Yamada, Y.; Yamaguchi, H. Chem
Pharm Bull 1992, 40, 2720.
[15] Gordaliza, M.; MaMiguel del Corral, J.; Castro, M. A.; López-
Vázquez, M.; García, P. A.; San Feliciano, A.; García-Grávalos, M.
Bioorg Med Chem Lett 1995, 5, 2465.
[16] Zavala, F.; Guenard, D.; Robin, J. P.; Brown, E. J Med Chem
1980, 23, 546.
[17] Heidary Alizadeh, B.; Foroumadi, A.; Emami, S.; Khoobi,
M.; Panah, F.; Ardestani, S. K.; Shafiee, A. Eur J Med Chem 2010,
45, 5979.
[18] Heidary Alizadeh, B.; Foroumadi, A.; Kobarfard, F.; Saeedi,
M.; Shafiee, A. J Heterocyclic Chem 2015, 52, 1693.
[19] Mohammadhosseini, N.; Moradi, S.; Khoobi, M.; Shafiee, A. J
Heterocyclic Chem 2015. DOI:10.1002/jhet.2470.
[20] Rahmani-Nezhad, S.; Safavi, M.; Pordeli, M.; Kabudanian
Ardestani, S.; Khosravani, L.; Pourshojaei, Y.; Mahdavi, M.; Emami,
S.; Foroumadi, A.; Shafiee, A. Eur J Med Chem 2014, 86, 562.
[21] Mahdavi, M.; Pedrood, K.; Safavi; Saeedi, M.; Pordeli, M.;
Kabudanian Ardestani, S.; Emami, S.; Adib, M.; Foroumadi, A.; Shafiee,
A. Eur J Med Chem 2015, 95, 492.
[22] Ramazani, A.; Khoobi, M.; Torkaman, A.; Zeinali Nasrabadi, F.;
Forootanfar, H.; Shakibaie, M.; Jafari, M.; Ameri, A.; Emami, S.; Faramarzi,
M. A.; Foroumadi, A.; Shafiee, A. Eur J Med Chem 2014, 78, 151.
[23] Molaverdi, F.; Khoobi, M.; Emami, S.; Alipour, M.; Firuzi, O.;
Foroumadi, A.; Dehghan, G.; Miri, R.; Shaki, F.; Jafarpour, F.; Shafiee, A.
Eur J Med Chem 2013, 68, 103.
Acknowledgment. This work was supported by grants from the
Iran National Science Foundation and Research Council of
Tehran University of Medical Sciences.
REFERENCES AND NOTES
[1] Ducasse, H.; Arnal, A.; Vittecoq, M.; Daoust, S. P.; Ujvari, B.;
Jacqueline, C.; Tissot, T.; Ewald, P.; Gatenby, R. A.; King, K. C.;
Bonhomme, F.; Brodeur, J.; Renaud, F.; Solary, E.; Roche, B.; Thomas,
F. Evol Appl 2015, 8, 527.
[2] Hasima,N.;Aggarwal,B.B.IntJBiochemMolBiol2012,3,328.
[3] National Cancer Institute. http://www.cancer.gov/about-can-
cer/what-is-cancer/statistics.
[24] Hanessian, S.; Ninkovic, S. Can J Chem 1996, 74, 1880.
[25] Xu, H.; Wang, J. J Bioorg Med Chem Lett 2010, 20, 2500.
[26] Mosmann, T. J Immunol Methods 1983, 65, 55.
[4] Kunjachan, S.; Rychlik, B.; Storm, G.; Kiessling, F.;
Lammers, T. Adv Drug Deliv Rev 2013, 65, 1852.
[5] Emami, S.; Dadashpour, S. Eur J Med Chem 2015, 102, 611.
Journal of Heterocyclic Chemistry
DOI 10.1002/jhet