Lewis Acid-Mediated Ring-Opening Reactions of trans-2-Aroyl-3-styrylcyclopropane-1,1-dicarboxylates: Access to Cyclopentenes and E,E-1,3-Dienes

Article abstract of DOI:10.1021/acs.joc.7b02335

The ring-opening reaction of trans-2-aroyl-3-styrylcyclopropane-1,1-dicarboxylates was investigated with different Lewis acids. With SnCl₄, the cyclopropane dicarboxylates afforded cyclopentene derivatives through ring opening followed by cyclization (vinylcyclopropane-cyclopentene rearrangement). With TiCl₄, they furnished E,E-1,3-diene derivatives stereoselectively via ring opening followed by proton elimination.

Full text of DOI:10.1021/acs.joc.7b02335

Subscriber access provided by READING UNIV
Article
Lewis Acid-Mediated Ring-Opening Reactions of
trans-2-Aroyl-3-styryl-cyclopropane-1,1-dicarboxylates:
Access to Cyclopentenes and E,E-1,3-Dienes
Murugesan Thangamani, and Srinivasan Kannupal
J. Org. Chem., Just Accepted Manuscript • DOI: 10.1021/acs.joc.7b02335 • Publication Date (Web): 18 Dec 2017
Downloaded from http://pubs.acs.org on December 18, 2017
Just Accepted
“Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted
online prior to technical editing, formatting for publication and author proofing. The American Chemical
Society provides “Just Accepted” as a free service to the research community to expedite the
dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts
appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been
fully peer reviewed, but should not be considered the official version of record. They are accessible to all
readers and citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered
to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published
in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just
Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor
changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers
and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors
or consequences arising from the use of information contained in these “Just Accepted” manuscripts.
The Journal of Organic Chemistry is published by the American Chemical Society.
1155 Sixteenth Street N.W., Washington, DC 20036
Published by American Chemical Society. Copyright © American Chemical Society.
However, no copyright claim is made to original U.S. Government works, or works
produced by employees of any Commonwealth realm Crown government in the course
of their duties.

Page 1 of 28
The Journal of Organic Chemistry
1
2
3
4
5
6
7
8
9
Lewis Acid-Mediated Ring-Opening Reactions of trans-2-Aroyl-3-
styryl-cyclopropane-1,1-dicarboxylates: Access to Cyclopentenes
and E,E-1,3-Dienes
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Murugesan Thangamani and Kannupal Srinivasan∗
School of Chemistry, Bharathidasan University, Tiruchirapalli 620 024, Tamil Nadu, India
srinivasank@bdu.ac.in
Ar2
O
TiCl4
SnCl4
EtO2C
CO2Et
Ar2
EtO2C
CO2Et
Ar2
(1 equiv.)
(1 equiv.)
Ar1
Ar1
CH2Cl2
rt, 8-12 h
CH2Cl2
rt, 8-12 h
EtO2C CO2Et
O
O
Ar1
63-86%
10 examples
67-90%
12 examples
Abstract: The ringꢀopening reaction of transꢀ2ꢀaroylꢀ3ꢀstyrylꢀcyclopropaneꢀ1,1ꢀdicarboxylates
was investigated with different Lewis acids. With SnCl4, the cyclopropane dicarboxylates
afforded cyclopentene derivatives through ring opening followed by cyclization
(vinylcyclopropaneꢀcyclopentene rearrangement). With TiCl4, they furnished E,Eꢀ1,3ꢀdiene
derivatives stereoselectively via ring opening followed by proton elimination.
INTRODUCTION
The popularity of donorꢀacceptor (DꢀA) cyclopropanes as versatile building blocks in
organic synthesis is mainly due to their easy accessibility and diverse reactivity.1 By varying the
donor and acceptor groups and placing a suitable group in the other vicinal position, the synthetic
potential of DꢀA cyclopropanes could be expanded vastly. Among different types of reactions of
ACS Paragon Plus Environment

The Journal of Organic Chemistry
Page 2 of 28
1
2
3
4
5
6
DꢀA cyclopropanes, their ring opening triggered by Lewis acids and/or nucleophiles constitutes
one of the effective means for synthesizing various cyclic and acylic products.2
7
8
9
A previous report from our laboratory has shown that transꢀ2ꢀaroylꢀ3ꢀarylꢀcyclopropaneꢀ
1,1ꢀdicarboxylates 1 upon treatment with AlCl3 or SnCl4 gave 2ꢀpyrones 2, whereas with TiCl4,
they form 1ꢀindanones 3 (Scheme 1, Eqn. 1).3 In the present work, we found that similar
cyclopropanes 4 having a styryl group instead of aryl as donor behaved very differently with the
same Lewis acids and afforded either cyclopentenes 5 or 1,3ꢀdienes 6 as products (Scheme 1,
Eqn. 2). The transformation of 4 to 5 is essentially a vinylcyclopropaneꢀcyclopentene
rearrangement, which is wellꢀknown for its intriguing mechanism and application in the total
synthesis of natural products.4 It is noteworthy that both cyclopentene and 1,3ꢀdiene cores are
present in numerous natural products5 and also many cyclopentene and 1,3ꢀdiene derivatives
serve as valuable synthetic precursors.6,7 Various methods have been reported for the synthesis of
cyclopentenes8 and also, for 1,3ꢀdienes9 and the present work represents a novel unified
approach for the access of both types of products from DꢀA cyclopropanes. Moreover, the work
demonstrates how a subtle change in the DꢀA cyclopropane structure influences the reaction
outcome drastically.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
ACS Paragon Plus Environment

Page 3 of 28
The Journal of Organic Chemistry
1
2
3
4
Previous work (Eqn. 1):
EtO2C
O
Ar1
Ar2
5
6
7
8
SnCl4
CH2Cl2, rt
O
EtO2C
Ar1
CO2Et
Ar2
2
9
Ar2
R
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
O
CO2Et
CO2Et
TiCl4
O
1
CH2Cl2, rt
Ar1
3
This work (Eqn. 2):
Ar2
SnCl4
Ar1
O
CH2Cl2, rt
EtO2C CO2Et
EtO2C
CO2Et
Ar2
5
EtO2C
CO2Et
Ar2
O
TiCl4
Ar1
4
Ar1
CH2Cl2, rt
O
6
Scheme 1. Comparison of Lewis acid mediated ring opening reactions of 1 and 4.
RESULTS AND DISCUSSION
The DꢀA cyclopropanes 4 required for the present study were prepared as single transꢀ
diastereomers in 88ꢀ94% yields by an iodine/DBUꢀmediated cyclisation of Michael adducts 8
(Table 1).10 The Michael adducts were in turn prepared by a baseꢀpromoted condensation of
cinnamaldehydes with acetophenones to give dienones 7 followed by LiClO4ꢀcatalyzed
conjugate addition of diethyl malonate to 7.11
ACS Paragon Plus Environment

The Journal of Organic Chemistry
Page 4 of 28
1
2
3
4
Table 1. Preparation of starting DꢀA cyclopropanes.
5
6
7
8
9
CHO
Diethyl
Ar1
O
malonate
NaOH
EtOH
+
O
Ar1
Ar2
LiClO4
(5 mol%)
Et3N, MeCN
7
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Ar2
EtO2C
CO2Et
Ar2
I2 (2 equiv.)
EtO2C
Ar1
CO2Et
O
DBU (2 equiv.)
PhMe, rt, 0.5 h
Ar2
O
Ar1
4
8
Entry
1
2
3
4
5
6
7
8
Ar1
Ph
4ꢀMeC6H4
Ar2
Ph
Ph
Yield (%)a
93 (4a)
90 (4b)
90 (4c)
89 (4d)
92 (4e)
88 (4f)
90 (4g)
90 (4h)
94 (4i)
4ꢀMeOC6H4 Ph
4ꢀClC6H4 Ph
4ꢀNO2C6H4 Ph
2ꢀnaphthyl
2ꢀthienyl
Ph
Ph
Ph
4ꢀMeC6H4
4ꢀMeC6H4
2ꢀthienyl
Ph
Ph
4ꢀMeC6H4
4ꢀClC6H4
4ꢀNO2C6H4
4ꢀMeC6H4
4ꢀClC6H4
4ꢀClC6H4
9
10
11
12
13
91 (4j)
92 (4k)
88 (4l)
88 (4m)
aIsolated yield (from 8)
To begin, we selected DꢀA cyclopropane 4a as a model substrate and treated with
different Lewis acids (Table 2). When 4a was treated with one equiv. of SnCl4 in
dichloromethane, the reaction gave a cyclopentene derivative 5a in 92% yield (entry 1). With
AlCl3 and TiCl4, the reaction afforded E,Eꢀ1,3ꢀdiene 6a; however, the yield was better with TiCl4
(entries 2 and 3). It is worth noting that similar olefin products are formed as intermediates in
TiCl4ꢀpromoted ring opening of 1, but the intermediates underwent further reaction (Nazarov
cyclization12) to give indenes 3.3 Upon treatment with BF3.OEt2, 4a underwent fragmentation to
yield phenacyl malonate (9, 40%) and cinnamaldehyde (10, 36%) (entry 4). When the amount of
ACS Paragon Plus Environment

Page 5 of 28
The Journal of Organic Chemistry
1
2
3
4
5
6
7
8
9
Lewis acid was reduced (0.5 equiv.), the pattern of the products was the same, but their yields
dropped proportionately (entries 5 and 6). Whilst, an increase in the amount of Lewis acid (1.5
equiv.) did not alter the yields significantly (entries 7 and 8). The same pattern of products, but
with inferior yields, were obtained by switching the solvent to 1,2ꢀdichloroethane (entry 9 and
10). The cyclopropane 4a did not undergo any change upon treatment with other Lewis acids
such as InCl3, ZnCl2, Ni(ClO4)2, Ag(OTf)3, Cu(OTf)2, In(OTf)3, Sc(OTf)3 and Yb(OTf)3 and a
Brønsted acid, pꢀTsOH. Thus, we selected SnCl4 or TiCl4 as optimal Lewis acids for the ringꢀ
opening of the cyclopropanes to obtain cyclopentenes and 1,3ꢀdienes.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Table 2. Optimization of reaction conditions for ring opening of 4a
Ph
Ph
O
CO2Et
CO2Et
O
EtO2C CO2Et
EtO2C
CO2Et
Ph
Ph
Ph
LA
5a
9
or
+
Solvent
rt, 12 h
EtO2C
CO2Et
Ph
O
4a
Ph
Ph
O
10
6a
O
Entry Lewis acid (equiv) Solvent
Product and
Yield (%)a
5a, 92
6a, 66
6a, 90
9,40 + 10, 36
5a, 28
1
2
3
4
5
6
7
8
9
10
SnCl4 (1.0)
AlCl3(1.0)
TiCl4(1.0)
BF3.OEt2(1.0)
SnCl4 (0.5)
TiCl4 (0.5)
SnCl4 (1.5)
TiCl4 (1.5)
SnCl4 (1.0)
TiCl4 (1.0)
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
1,2ꢀDCE
1,2ꢀDCE
6a, 34
5a, 90
6a, 90
5a, 70
6a, 62
aIsolated yield
ACS Paragon Plus Environment

The Journal of Organic Chemistry
Page 6 of 28
1
2
3
4
5
6
7
8
9
A plausible mechanism for the formation of the products 5a, 6a, 9 and 10 from 4a is
depicted in Scheme 2. When 4a was treated with SnCl4, the Lewis acid coordinates to the gemꢀ
diester unit thereby leading to the C1ꢀC3 bond cleavage. The resulting 1,3ꢀzwitterion A
undergoes intramolecular cyclisation to give cyclopentene B (a β,γꢀunsaturated ketone), which
rearranges to thermodynamically more stable cyclopentene 5a (an α,βꢀunsaturated ketone). On
the other hand, when treated with TiCl4, 4a forms the intimate ion pair C via C1ꢀC3 bond
cleavage and SNiꢀlike attack by chloride ion (which comes from TiCl4)3 and the ion pair C
undergoes an E2ꢀlike elimination to give E,Eꢀ1,3ꢀdiene 6a stereoselectively. In case of BF3.OEt2,
4a initially forms the zwitterion A, which then combines water (moisture) and undergoes
fragmentation to yield 9 and 10.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
OEt
CO2Et
CO2Et
O
Ph
H
When
LA = BF3 OEt2
Ph
O
When
O
1
LA = SnCl4
Ph
EtO2C
2
LA
O
3
H
Ph
H
O
Ph
CO2Et
OEt
4a
A
A
Ph
H2O (moisture)
When
LA = TiCl4
Ph
O
O
O
CO2Et
CO2Et
Ph
Ph
CO2Et
O
OEt
O
Ph
H
EtO2C CO2Et
CO2Et
O
Ph
E2
6a
Ph
B
SNi
LA
D
Cl
O
H
H
OEt
H
5a
C
9 + 10
Ph
Ph
Scheme 2. Mechanism for the formation of different products from 4a (the Lewis acid
coordination is not shown in the intermediate structures for clarity)
ACS Paragon Plus Environment

Page 7 of 28
The Journal of Organic Chemistry
1
2
3
4
5
6
Next, we turned our attention on investigating the scope of the SnCl4 and TiCl4ꢀmediated
reactions with respect to various DꢀA cyclopropanes.
7
8
9
As shown in Table 3, DꢀA cyclopropanes having various aromatic rings as Ar1 and Ar2
could be successfully employed for the cyclopentene synthesis. As the Ar1 ring was involved in
the stabilization of positive charge in the zwitterionic intermediate formed during the
transformation, the nature of Ar1 ring was expected to have more influence on the reaction
outcome as compared to Ar2 ring. The presence of electron donating and halogen substituents on
the Ar1 ring was tolerated in the reaction and the expected cyclopentene derivatives 5a–d were
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
produced in good yields (entries 1
–4). However, when an electron withdrawing nitroꢀsubstituent
was present on the Ar1 ring, the reaction gave a mixture of fragmentation products,
p
ꢀ
nitrocinnamaldehyde and phenacyl malonate instead of the expected cyclopentene product (the
product pattern was similar to the one obtained with BF3.OEt2) (entry 5). Apart from substituted
phenyl rings, a bulky naphthyl ring (entry 6) or heteroaromatic, 2ꢀthienyl ring (entry 7) could be
fruitfully used as Ar1 to obtain the respective cyclopentene derivatives 5f and 5g. As expected,
the presence of electron donating/withdrawing and halogen substituents on the Ar2 ring of the Dꢀ
A cyclopropanes afforded the corresponding cyclopentenes without any problem (entries 8
–10).
Finally, cyclopropanes carrying substituents on both aromatic rings (Ar1 and Ar2) also gave the
respective cyclopentenes in good yields (entries 11
ray crystallographic analysis13).
–13, the structure of 5l was confirmed by Xꢀ
ACS Paragon Plus Environment

The Journal of Organic Chemistry
Page 8 of 28
1
2
3
4
Table 3. The scope of formation of cyclopentenes for various DꢀA cyclopropanes
5
6
7
8
9
Ar2
SnCl4
EtO2C
CO2Et
Ar2
(1 equiv.)
Ar1
O
CH2Cl2, rt
EtO2C CO2Et
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
O
Ar1
4
5
Entry
1
2
3
4
5
6
7
8
Ar1
Ar2
Yield (%)a
83 (5a
86 (5b
80 (5c
Ph
4ꢀMeC6H4
4ꢀMeOC6H4 Ph
4ꢀClC6H4 Ph
4ꢀNO2C6H4 Ph
2ꢀnaphthyl
2ꢀthienyl
Ph
Ph
Ph
)
)
)
b
70 (5d
)
c
–
Ph
Ph
82 (5e)
75 (5f
90 (5g)
77 (5h)
67 (5i
79 (5j
76 (5k
b
)
4ꢀMeC6H4
4ꢀClC6H4
4ꢀNO2C6H4
4ꢀMeC6H4
4ꢀClC6H4
4ꢀClC6H4
9
Ph
Ph
10
11
12
13
)
)
)
)
4ꢀMeC6H4
4ꢀMeC6H4
2ꢀthienyl
71 (5l
aIsolated yields. bInseparable impurities (about 5%) were present
along with the product. cpꢀNitrocinnamaldehyde (45%) and phenacyl
malonate (40%) are produced instead of cyclopentene product
Having studied the scope of cyclopentene synthesis for various DꢀA cyclopropanes, we
next focused attention on synthesis of E,Eꢀ1,3ꢀdienes from the cyclopropanes (Table 4).
Pleasingly, cyclopropanes having electron donating/withdrawing and halogen substituents on
both aromatic rings (Ar1 and Ar2) as well as those with naphthyl and thienyl rings as Ar1 were
compatible in the transformation and the respective 1,3ꢀdienes were formed in 63ꢀ86% yields
(entries 1
–
10, the structure of 6d was confirmed by Xꢀray crystallographic analysis14). It is
ꢀnitrophenyl ring also furnished the
interesting to note that the DꢀA cyclopropane having a
p
expected 1,3ꢀdiene without out undergoing any fragmentation reaction as observed with SnCl4.
ACS Paragon Plus Environment

Page 9 of 28
The Journal of Organic Chemistry
1
2
3
4
Table 4. The scope of formation of 1,3ꢀdienes for various DꢀA cyclopropanes
5
6
7
8
9
TiCl4
EtO2C
CO2Et
Ar2
EtO2C
CO2Et
Ar2
(1 equiv.)
Ar1
CH2Cl2, rt
O
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
4
6
O
Ar1
Entry
1
2
3
4
5
6
7
Ar1
Ar2
Yield (%)a
86 (6a
80 (6b
74 (6c
83 (6d
70 (6e
Ph
Ph
)
)
)
)
4ꢀMeOC6H4 Ph
4ꢀClC6H4 Ph
4ꢀNO2C6H4 Ph
2ꢀnaphthyl
2ꢀthienyl
Ph
Ph
Ph
)
77 (6f
)
4ꢀMeC6H4
4ꢀClC6H4
4ꢀNO2C6H4
4ꢀMeC6H4
82 (6g)
75 (6h)
8
9
Ph
Ph
63 (6i
)
10
4ꢀMeC6H4
78 (6j)
aIsolated yields.
The products, cyclopentenes and E,Eꢀ1,3ꢀdienes could serve as versatile synthetic
intermediates. To prove the point, we subjected cyclopentene 5a to catalytic hydrogenation and
obtained cyclopentane 11 as a diastereomeric mixture (2.6:1) in 85% total yield (Scheme 3).
Similarly, when diene 6b was treated with SnCl4, it underwent intramolecular cyclization to give
chlorocyclopentene derivative 12 in 77% yield.
ACS Paragon Plus Environment

The Journal of Organic Chemistry
Page 10 of 28
1
2
3
4
5
6
Ph
O
Ph
O
H2, 5% Pd/C (10 mol%)
Ph
Ph
MeOH, rt, 8 h
EtO2C CO2Et
EtO2C CO2Et
7
8
11 (dr 2.6:1), 85%
5a
9
Cl
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
SnCl4
(1 equiv.)
EtO2C
Ar
CO2Et
Ph
Ph
Ar
EtO2C CO2Et
O
CH2Cl2, rt, 12 h
Ar = 4-MeOC6H4
O
6b
12, 77%
Scheme 3. Synthetic applications of a cyclopentene and a 1,3ꢀdiene
CONCLUSIONS
In conclusion, the treatment of transꢀ2ꢀaroylꢀ3ꢀstyrylꢀcyclopropaneꢀ1,1ꢀdicarboxylates
with different Lewis acids gave different types of products. Upon treatment with SnCl4, they
underwent vinylcyclopropaneꢀcyclopentene rearrangement via tandem ringꢀopening and ringꢀ
closing to yield cyclopentenes. On the other hand, they afforded E,Eꢀ1,3 dienes by ringꢀopening
and E2ꢀlike elimination of proton upon treatment with TiCl4. With BF3.OEt2, they afforded
fragmentation products. The scope of cyclopentene and 1,3ꢀdiene synthesis was investigated for
various DꢀA cyclopropanes and established that the protocols are indeed handy for the access of
these two classes of compounds.
EXPERIMENTAL SECTION
General remarks: Melting points were determined by the open capillary tube method and are
uncorrected. The H and 13C NMR spectra were recorded on a 400 or 500 MHz NMR
1
spectrometer. HRMS (ESI) were recorded on Exactive Plus EMR Orbitrap or QꢀTOF mass
ACS Paragon Plus Environment

Page 11 of 28
The Journal of Organic Chemistry
1
2
3
4
5
6
spectrometers. Xꢀray crystallographic data were collected on a CCD diffractometer using
graphiteꢀmonochromated MoꢀKα radiation. Thin layer chromatography (TLC) was performed on
7
8
9
preꢀcoated alumina sheets and detected under UV light.
column chromatography.
Silica gel (100ꢀ200 mesh) was used for
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
General procedure for the synthesis of trans-2-aroyl-3-styryl-cyclopropane-1,1-
dicarboxylates 4a-m: To a solution of Michael adduct 811 (1 mmol) in toluene (5 mL) were
added DBU (0.3mL; 2 mmol) and iodine (508 mg; 2 mmol). The reaction mixture was stirred at
ambient temperature for 30 min. After the reaction was complete, the reaction mixture was
quenched with aq. Na2 S2 O3 and extracted with ethyl acetate. The organic layer was washed with
water and dried (anhydrous Na2SO4), and the solvent was removed under reduced pressure. The
crude product was purified by column chromatography using ethyl acetate (5ꢀ10%)/hexane to
give pure product.
Diethyl trans-2-benzoyl-3-styrylcyclopropane-1,1-dicarboxylate (4a): Yellow solid; Yield:
366 mg (93%); M. p.: 50–52 οC; 1H NMR (400 MHz, CDCl3):
δ
8.04–8.02 (m, 2H), 7.61 (d,
= 15.6 Hz, 1H), 6.07 (dd,
J
J
=
=
7.6 Hz, 1H), 7.48 (t, = 7.6 Hz, 2H), 7.35–7.23 (m, 5H), 6.80 (d,
J
J
15.6, 9.2 Hz, 1H), 4.34–4.15 (m, 4H ), 3.83 (d,
J = 7.2 Hz, 1H), 3.37 (dd, J = 9.2, 6.8 Hz 1H),
1.27 (t,
J
= 7.2 Hz, 3H),1.16(t,
J
= 7.2 Hz, 3H) ppm; 13C NMR (100 MHz, CDCl3):
δ193.7,
166.7, 165.8, 136.9, 136.5, 135.3, 133.6, 128.74, 128.65, 128.5, 127.9, 126.3, 122.4, 62.4, 61.9,
45.3, 37.0, 36.0, 14.2, 13.9 ppm; HRMS (ESIꢀion trap) m/z: [M + Na]+ Calcd for C24H24O5Na
415.1516; found: 415.1511.
ACS Paragon Plus Environment

The Journal of Organic Chemistry
Page 12 of 28
1
2
3
4
Diethyl trans-2-benzoyl-3-(4-methylstyryl)-cyclopropane-1,1-dicarboxylate (4b): Yellow
5
6
7
8
1
liquid; Yield: 365 mg (90%); H NMR (400 MHz, CDCl3):
δ
7.96 (d,
J
= 8.0 Hz, 2H), 7.47 (d,
J
J
=7.6 Hz, 3H), 7.25 (d,
= 16.0, 9.2 Hz, 1H), 4.34–4.18 (m, 4H), 3.87 (d,
2.38 (s, 3H), 1.26 (t, = 7.0 Hz, 3H), 1.17 (t,
CDCl3):
J
= 8Hz, 2H), 7.10 (d,
J
= 8 Hz, 2H), 6.79 (d,
J = 16.0 Hz, 1H), 6.13 (dd,
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
J
= 7.2 Hz, 1H), 3.41 (dd,
J = 9.2, 7.2 Hz, 1H),
J
J
= 7.2 Hz, 3H) ppm; 13C NMR (100 MHz,
δ
193.1, 166.8, 165.9, 144.5, 136.5, 135.2, 134.5, 129.4, 128.7, 127.9, 126.3, 122.5,
62.3, 61.8, 45.2, 36.9, 35.9, 21.7, 14.2, 13.9 ppm; HRMS (ESIꢀion trap) m/z: [M + H]+ Calcd for
C25H27O5 407.1853; found: 407.1852.
Diethyl trans-2-benzoyl-3-(4-methoxystyryl)-cyclopropane-1,1-dicarboxylate (4c): Yellow
liquid; Yield: 378 mg (90%) ; 1H NMR (400 MHz, CDCl3):
= 7.2 Hz, 1H), 7.45 (t, = 7.8 Hz, 2H), 7.27 (d, = 8.4 Hz, 2H), 6.82 (d,
(d, = 16.0 Hz, 1H), 5.96 (dd, = 16.0, 9.2 Hz, 1H), 4.30–4.15 (m, 4H), 3.84 (d,
= 8.0 Hz, 1H ), 1.25 (t, = 7.2 Hz, 3H), 1.15 (t, = 7.2 Hz, 3H) ppm;
193.7, 166.7, 165.9, 159.5, 136.9, 134.7, 133.6, 129.3, 128.7,
δ
8.03 (d,
J
= 8.0 Hz, 2H), 7.55 (t,
= 8.4 Hz, 2H), 6.72
= 7.2 Hz,
J
J
J
J
J
J
J
1H), 3.72 (s, 3H), 3.38 (t,
J
J
J
13C NMR (100 MHz, CDCl3):
δ
128.5, 127.5, 119.9, 114.1, 62.3, 61.8, 55.2, 45.3, 37.0, 36.2, 14.2, 13.9 ppm; HRMS (ESIꢀion
trap) m/z: [M + H]+ Calcd for C25H27O6 423.1802; found: 423.1796.
Diethyl trans-2-benzoyl-3-(4-chlorostyryl)-cyclopropane-1,1-dicarboxylate (4d): Yellow
liquid; Yield: 380 mg (89%); 1H NMR (400 MHz, CDCl3):
δ
8.04–8.02 (m,2H), 7.60–7.56 (m,
= 16.0, 6.8 Hz,
= 8.0 Hz, 1H), 1.26 (t, = 7.2 Hz,
193.5, 166.6, 165.7, 136.8,
1H), 7.49–7.45 (m, 2H), 7.25 (s, 4H), 6.73(dd, = 16.0, 2.0 Hz, 1H), 6.08 (dd,
J
J
1H), 4.23–4.15 (m, 4H), 3.85 (d,
3H), 1.15 (t,
J
= 6.8 Hz, 1H), 3.37 (t,
J
J
13
J
= 7.0 Hz, 3H) ppm; C NMR (100 MHz, CDCl3):
δ
135.0, 133.9, 133.7, 133.4, 128.78, 128.75, 128.5, 127.5, 123.1, 62.4, 61.9, 45.3, 36.9, 35.8, 14.2,
ACS Paragon Plus Environment

Page 13 of 28
The Journal of Organic Chemistry
1
2
3
4
13.9 ppm; HRMS (ESIꢀion trap) m/z: [M + H]+ Calcd for C24H24ClO5 427.1307; found:
5
6
427.1303.
7
8
9
Diethyl trans-2-benzoyl-3-(4-nitrostyryl)-cyclopropane-1,1-dicarboxylate (4e): Yellow
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
liquid; Yield: 400 mg (92%); 1H NMR (400 MHz, CDCl3):
δ
8.10 (d,
J
= 8.8 Hz, 2H), 8.04 (d,
J
= 7.2 Hz, 2H), 7.64–7.60 (m, 1H), 7.53–7.47 (m, 4H), 6.87 (d,
J
= 16.0 Hz, 1H), 6.31 (dd,
J
=
16.0, 9.2 Hz, 1H), 4.35–4.15 (m, 4H), 3.90 (d,
1.29 (t, = 7.0 Hz, 3H), 1.16 (t,
J
= 6.8 Hz 1H), 3.42 (dd,
J
= 9.4, 7.0 Hz, 1H),
193.2,
13
J
J
= 7.0 Hz, 3H) ppm; C NMR (100 MHz, CDCl3):
δ
166.6, 165.4, 147.0, 142.8, 136.7, 133.8, 133.1, 128.8, 128.5, 127.7, 126.8, 124.1, 62.6, 62.0,
45.4, 36.9, 35.6, 14.1, 13.9 ppm; HRMS (ESIꢀion trap) m/z: [M + Na]+ Calcd for C24H23NO7Na
460.1367; found: 460.1356.
Diethyl trans-2-benzoyl-3-(2-naphthalen-2-yl-vinyl)-cyclopropane-1,1-dicarboxylate (4f):
1
Yellow liquid; Yield: 388 mg (88%) ; H NMR (400 MHz, CDCl3):
δ
8.01(d, = 8.4 Hz, 2H),
J
7.49 (d,
1H), 4.38–4.20 (m, 4H), 3.82 (d,
3H), 1.21 (t,
J
= 8.4 3H), 7.39–7.27 (m, 7H), 6.84 (d,
J
= 15.6 Hz, 1H), 6.11 (dd, J = 15.6, 9.2 Hz,
J
= 6.8 Hz, 1H ), 3.42 (t,
J
= 7.8 Hz, 1H), 1.31 (t,
J = 7.2 Hz,
13
J
= 7.0 Hz, 3H) ppm; C NMR (100 MHz, CDCl3) :
δ
192.4, 166.6, 165.7, 140.1,
136.4, 135.4, 135.3, 129.9, 129.1, 128.7, 127.9, 126.3, 122.1, 62.5, 62.0, 45.4, 36.9, 35.89, 14.1,
13.9 ppm; HRMS (ESIꢀion trap) m/z: [M + Na]+ Calcd for C28H26O5Na 465.1672; found:
465.1670.
Diethyl trans-2-benzoyl-3-(2-thiophen-2-yl-vinyl)-cyclopropane-1,1-dicarboxylate (4g):
Yellow liquid; Yield: 360 mg (90%); 1H NMR (400 MHz, CDCl3):
7.56 (d, = 7.2 Hz, 1H), 7.47 (t, = 7.4 Hz, 2H), 7.12 (d, = 4.0 Hz, 1H), 6.92 (t,
3H), 5.91 (dd, = 15.6, 9.2 Hz, 1H), 4.27 (q, = 7.0 Hz, 2H), 4.16 (d, = 7.2 Hz, 2H), 3.81 (d, J
δ
8.02 (d,
J
= 8.0 Hz, 2H),
= 5.8 Hz,
J
J
J
J
J
J
J
ACS Paragon Plus Environment

The Journal of Organic Chemistry
Page 14 of 28
1
2
3
4
= 6.8 Hz, 1H) 3.32 (t,
J
= 8.0 Hz, 1H), 1.27 (t,
J = 7.2 Hz, 3H), 1.15 (t, J
= 7.0 Hz, 3H) ppm; 13C
5
6
NMR (100 MHz, CDCl3):
δ
193.5, 166.6, 165.7, 141.5, 136.8, 133.7, 128.8, 128.5, 128.3, 127.5,
7
8
9
126.0, 124.5, 121.8, 62.4, 61.9, 45.3, 36.8, 35.8, 14.2, 13.9 ppm; HRMS (ESIꢀion trap) m/z: [M
+ Na]+ Calcd for C22H22O5NaS 421.1080; found: 421.1088.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Diethyl trans-2-(4-methylbenzoyl)-3-styryl-cyclopropane-1,1-dicarboxylate (4h): Yellow
liquid; Yield: 364 (90%); 1H NMR (400 MHz, CDCl3):
7H), 6.79 (d, = 15.6 Hz, 1H), 6.07 (dd, = 16.0, 9.2 Hz, 1H), 4.30–4.15 (m, 4H), 3.81 (d,
= 7.2 Hz, 3H), 1.17 (t, = 7.2
193.1, 166.8, 165.9, 144.6, 136.6, 135.2, 134.5,
δ 7.93 (d, J = 8.0 Hz, 2H), 7.35–7.22 (m,
J
J
J =
6.8 Hz, 1H), 3.35 (dd,
J
= 9.0, 7.0 Hz, 1H), 2.40 (s, 3H), 1.27 (t,
J
J
Hz, 3H) ppm; 13C NMR (100 MHz, CDCl3):
δ
129.4, 128.7, 127.9, 126.3, 122.5, 62.3, 61.8, 45.2, 36.9, 35.9, 21.7, 14.2, 13.9 ppm; HRMS
(ESIꢀion trap) m/z: [M + H]+ Calcd for C25H27O5 407.1853; found: 407.1854.
Diethyl trans-2-(4-chlorobenzoyl)-3-styryl-cyclopropane-1,1-dicarboxylate (4i): Yellow
1
liquid; Yield: 401 g (94%); H NMR (400 MHz, CDCl3):
δ
7.97 (d,
= 16.0 Hz, 1H), 6.09 (dd,
= 6.8 Hz, 1H), 3.36 (t,
J
= 8.4 Hz, 2H), 7.46 (d,
= 15.8, 9.0 Hz, 1H), 4.31–
= 7.0 Hz, 3H), 1.16 (t,
192.4, 166.6, 165.6, 140.1, 136.5, 135.4,
J =
8.0 Hz, 2H), 7.33–7.23 (m, 5H), 6.79 (d,
J
J
4.15 (m, 4H), 3.75 (d,
J
J
= 7.8 Hz, 1H), 1.27 ( t,
J
13
J
= 7.0 Hz, 3H) ppm; C NMR (100 MHz, CDCl3):
δ
135.3, 129.9, 129.1, 128.6, 127.9, 126.3, 122.1, 62.4, 61.9, 45.4, 36.9, 35.8, 14.1, 13.9 ppm;
HRMS (ESIꢀion trap) m/z: [M + H]+ Calcd for C24H24ClO5 427.1307; found: 427.1307.
Diethyl trans-2-(4-nitrobenzoyl)-3-styryl-cyclopropane-1,1-dicarboxylate (4j): Yellow
1
liquid; Yield: 398 mg (91%); H NMR (400 MHz, CDCl3):
δ
8.34–8.17 (m,4H), 7.35–7.25 (m,
= 15.8, 9.0 Hz, 1H), 4.31–4.15 (m, 4H), 3.76 (d,
= 8.8, 7.2 Hz, 1H), 1.29 (t, = 7.2 Hz, 3H), 1.18 (t, = 7.2 Hz, 3H)
5H), 6.82 (d,
J
= 14.4 Hz, 1H), 6.05 (dd,
J
J =
7.2 Hz, 1H), 3.36 (dd,
J
J
J
ACS Paragon Plus Environment

Page 15 of 28
The Journal of Organic Chemistry
1
2
3
4
ppm; 13C NMR (100 MHz, CDCl3):
δ 192.5, 166.3, 165.4, 150.6, 141.2, 136.2, 135.7, 129.5,
5
6
128.7, 128.1, 126.3, 124.0, 121.6, 62.7, 62.1, 45.8, 37.1, 36.3, 14.1, 13.9 ppm; HRMS (ESIꢀion
7
8
9
trap) m/z: [M + Na]+ Calcd for C24H23NO7Na 460.1367; found: 460.1368.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Diethyl trans-2-(4-methylbenzoyl)-3-(4-methylstyryl)-cyclopropane-1,1-dicarboxylate (4k):
1
Yellow liquid; Yield: 388 mg (92%); H NMR (400 MHz, CDCl3):
δ
7.93 (d,
J
J
= 8.0 Hz, 2H),
= 16.0, 9.2 Hz,
7.28–7.23 (m, 4H), 7.10 (d,
1H), 4.30–4.15 (m, 4H), 3.80 (d,
3H ), 1.26 (t, = 7.0 Hz, 3H), 1.17 (t,
J
= 7.6 Hz, 2H), 6.76 (d,
J = 15.6 Hz 1H), 6.01 (dd,
J
= 8.2 Hz, 1H), 3.33 (t,
J
= 8.8 Hz, 1H), 2.41 (s, 3H), 2.32 (s,
13
J
J
= 7.2 Hz, 3H) ppm; C NMR (100 MHz, CDCl3):
δ
193.2, 166.8, 166.0, 144.5, 137.7, 135.1, 134.5, 133.8, 129.4, 129.3, 128.7, 126.2, 121.4, 62.3,
61.8, 45.2, 36.9, 36.1, 21.7, 21.2, 14.2, 13.9 ppm; HRMS (ESIꢀion trap) m/z: [M + H]+ Calcd for
C26H29O5 421.2010; found: 421.2008.
Diethyl trans-2-(4-chlorobenzoyl)-3-(4-methylstyryl)-cyclopropane-1,1-dicarboxylate (4l):
1
Yellow liquid; Yield: 386 mg (88%); H NMR (400 MHz, CDCl3):
δ
7.97 (d,
= 7.6 Hz, 2H), 6.76 (d,
= 15.6, 9.2 Hz, 1H), 4.33–4.13 (m, 4H), 3.75 (d, = 6.8 Hz, 1H), 3.34 (t,
Hz, 1H), 2.33 (s, 3H), 1.27 ( t, = 7.0 Hz, 3H), 1.69 (t, = 7.2 Hz, 3H) ppm; C NMR (100
MHz, CDCl3): 192.6, 166.6, 165.8, 140.1, 137.8, 135.3, 135.2, 133.6, 129.9, 129.4, 129.1,
J
= 8.0 Hz, 2H),
= 16.0 Hz,
= 8.0
7.46 (d,
J
= 8.4 Hz, 2H), 7.24 (d,
J
= 8.0 Hz , 2H), 7.11 (d,
J
J
1H), 6.0 (dd,
J
J
J
13
J
J
δ
126.2, 120.9, 62.5, 62.0, 45.4, 36.9, 36.1, 21.3, 14.2, 13.9 ppm; HRMS (ESIꢀion trap) m/z: [M +
H]+ Calcd for C25H26ClO5 441.1463; found: 441.1461.
Diethyl trans-2-(4-chlorobenzoyl)-3-(2-thiophen-2-yl-vinyl)-cyclopropane-1,1-dicarboxylate
1
(4m): Yellow liquid; Yield: 380 mg (88%); H NMR (400 MHz, CDCl3):
δ
7.96 (d,
J
= 8.4 Hz,
2H), 7.46 (d,
J
= 8.4 Hz, 2H), 7.15 (t,
J
= 3.2 Hz, 1H), 6.95–6.89 (m, 3H), 5.87 (dd,
J
= 15.6, 9.2
ACS Paragon Plus Environment

The Journal of Organic Chemistry
Page 16 of 28
1
2
3
4
5
6
Hz, 1H), 4.34–4.15 (m, 4H), 3.74 (d,
7.2 Hz, 3H), 1.16 (t,
J
= 6.8 Hz, 1H), 3.30 (dd,
J
= 15.2, 8.0 Hz, 1H), 1.29 (t,
J =
13
J
= 7.2 Hz, 3H) ppm; C NMR (100 MHz, CDCl3):
δ
192.4, 166.5, 165.6,
7
8
9
141.4, 140.2, 135.2, 129.9, 129.1, 128.4, 127.5, 126.0, 124.6, 121.6, 62.6, 62.0, 45.4, 36.7, 35.8,
14.2, 13.9 ppm; HRMS (ESIꢀion trap) m/z: [M + Na]+ Calcd for C22H21ClO5NaS 455.0690;
found: 455.0690.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
General procedure for the synthesis of cyclopentenes 5a–l and 1,3-dienes 6a-j: To a solution
of transꢀ2ꢀaroylꢀ3ꢀstyrylꢀcyclopropaneꢀ1,1ꢀdicarboxylates (1 mmol) in dichloromethane (5 mL)
was added Lewis acid (SnCl4 for
5 and TiCl4 for 6; 1 mmol) at room temperature. The reaction
mixture was stirred at room temperature and monitored by TLC. After the reaction was
complete, the reaction mixture was quenched with ice–water and extracted with
dichloromethane. The combined organic layers were washed with brine, dried over anhydrous
Na2SO4 and evaporated under vacuum. The crude product was purified by column
chromatography on silica gel using ethyl acetate/hexane (1:9) as the eluent to give pure product.
Diethyl 2–benzoyl–5–phenyl–cyclopent–2–ene–1,1–dicarboxylate (5a): Yellow liquid; Yield:
1
326 mg (83%); H NMR (400 MHz, CDCl3):
δ 7.92–7.89 (m, 2H), 7.55 (t, J = 6.8 Hz, 1H),
7.47–7.44 (m, 2H), 7.39–7.37 (m, 2H), 7.31–7.25 (m, 3H), 6.64 (s, 1H), 4.28–4.21 (m, 3H),
3.81–3.66 (m, 2H), 3.17 (ddd,
J
= 18.0, 8.4, 1.6 Hz, 1H), 3.05 (ddd, ,
J
= 8.8, 6.8, 2.4 Hz, 1H) ,
192.3,
13
1.22 (t, = 8.0 Hz, 3H), 0.87 (t,
J
J
= 7.2 Hz, 3H) ppm; C NMR (100 MHz, CDCl3):
δ
170.7, 168.1, 145.3, 142.6, 139.8, 137.7, 132.7, 129.5, 128.8, 128.4, 128.1, 127.4, 72.4, 61.8,
61.2, 51.6, 40.0, 13.9, 13.6 ppm; HRMS (ESIꢀTOF) m/z: [M + H]+ Calcd for C24H25O5 393.1697;
found: 393.1700.
ACS Paragon Plus Environment

Page 17 of 28
The Journal of Organic Chemistry
1
2
3
4
Diethyl 2–benzoyl–5–p–tolyl–cyclopent–2–ene–1,1–dicarboxylate (5b): Yellow liquid; Yield:
5
6
7
8
350 mg (86%); 1H NMR (400 MHz, CDCl3):
7.46 (t, = 7.4 Hz , 2H), 7.26 (d, = 8.0 Hz, 2H), 7.10 (d,
1H), 4.24 (t, J =7.2, 3H), 3.84–3.71 (m, 2H), 3.16 (ddd,
= 18.0, 6.8, 2.0, Hz, 1H) 2.31 (s, 3H), 1.21 (t,
NMR (100 MHz, CDCl3):
δ
7.90 (d,
J
= 7.6 Hz, 2H), 7.56 (t,
J
= 7.4 Hz, 1H),
= 2.2 Hz ,
J
J
J
= 8.0 Hz , 2H), 6.64 (t, J
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
J
= 18.4, 8.4, 2.4, Hz, 1H), 3.02 (ddd,
J
J
= 7.2 Hz, 3H), 0.90 (t, J
= 7.2 Hz, 3H) ppm; 13C
δ
192.3, 170.7, 168.1, 145.2, 137.8, 136.9, 136.6, 132.6, 129.4, 128.8,
128.7, 128.3, 72.3, 62.5, 61.7, 61.1, 51.4, 39.9, 21.0, 13.9, 13.5 ppm; HRMS (ESIꢀTOF) m/z: [M
+ H]+ Calcd for C25H27O5 407.1853; found: 407.1859.
Diethyl 2–benzoyl–5–(4–methoxyphenyl)–cyclopent–2–ene–1,1–dicarboxylate (5c): Pale
yellow liquid; Yield: 336 mg (80%); 1H NMR (400 MHz, CDCl3):
7.59–7.55 (m, 1H), 7.47 (t, = 8.0 Hz, 2H), 7.31 (d, = 8.8Hz, 2H), 6.84 (d,
6.65 (t, = 2.4 Hz, 1H), 4.27–4.20 (m, 3H), 3.87–3.73 (m, 5H), 3.16 (ddd,
δ
7.89 (t,
J
= 4.2 Hz, 2H),
J
J
J = 8.4 Hz, 2H),
J
J
= 18.4, 8.4, 2.4,
= 7.2 Hz, 3H)
192.3, 170.7, 168.2, 158.9, 145.2, 142.7, 137.7, 132.6,
Hz, 1H), 3.02 (ddd,
J = 18.4, 7.2, 2.4, Hz, 1H), 1.21 (t, J = 7.2 Hz, 3H), 0.93 (t, J
ppm; 13C NMR (100 MHz, CDCl3):
δ
131.5, 129.9, 129.4, 128.3, 113.4, 72.2, 61.8, 61.2, 55.3, 51.0, 39.9, 13.9, 13.6 ppm; HRMS
(ESIꢀTOF) m/z: [M + H]+ Calcd for C25H27O6 423.1802; found: 423.1808.
Diethyl 2–benzoyl–5–(4–chlorophenyl)–cyclopent–2–ene–1,1–dicarboxylate (5d): Yellow
liquid; Yield: 300 mg (70%); 1H NMR (400 MHz, CDCl3):
Hz, 1H), 7.56–7.47 (m, 2H), 7.37–7.22 (m, 3H), 6.82 (dd,
Hz, 1H), 4.26–4.21 (m, 3H), 3.86–3.77 (m, 2H), 3.16 (ddd,
δ
7.90–7.87 (m, 2H), 7.57 (d,
= 6.0, 4.8, Hz, 1H), 6.64 (d,
J
J
= 6.4
= 2.4
J
J
= 18.0, 8.4, 2.4, Hz, 1H), 3.01(ddd,
J
= 18.4, 7.2, 2.4, Hz, 1H), 1.20 (t, J = 7.2 Hz, 3H), 0.94 (t, J
= 7.2 Hz, 3H) ppm; 13C NMR (100
MHz, CDCl3):
δ
192.2, 170.6, 168.1, 150.0, 144.9, 142.6, 138.0, 137.6, 133.2, 132.7, 130.3,
ACS Paragon Plus Environment

The Journal of Organic Chemistry
Page 18 of 28
1
2
3
4
129.4, 128.4, 128.2, 72.2, 61.7, 61.9, 61.4, 50.8, 39.6, 13.9, 13.6 ppm; HRMS (ESIꢀTOF) m/z
:
5
6
[M + H]+ Calcd for C24H24ClO5 427.1307; found: 427.1312.
7
8
9
Diethyl 2–benzoyl–5–naphthalen–2–yl–cyclopent–2–ene–1,1–dicarboxylate (5e): Yellow
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
1
liquid; Yield: 364 mg (82%); H NMR (400 MHz, CDCl3):
δ
7.94–7.92 (m, 2H), 7.82–7.77 (m,
4H), 7.57–7.43 (m, 6H), 6.69 (t,
J = 2.2, 1H), 4.46 (t, J = 7.6 Hz, 1H), 4.29–4.27 (m, 2H), 3.71–
3.60 (m, 2H), 3.25 (ddd,
J
= 18.4, 8.4, 2.4, Hz, 1H), 3.16 (ddd,
J
= 18.0, 6.8, 2.4, Hz, 1H), 1.23
192.3, 170.8,
13
(t, = 7.2 Hz, 3H), 0.72 (t,
J
J
= 7.2 Hz, 3H) ppm; C NMR (100 MHz, CDCl3):
δ
168.1, 145.2, 142.8, 137.8, 137.2, 133.2, 132.72, 132.66, 129.5, 128.4, 127.9, 127.73, 127.70,
127.5, 126.8, 126.1, 125.9, 72.4, 61.9, 61.2, 51.8, 40.0,13.9, 13.4 ppm; HRMS (ESIꢀTOF) m/z
:
[M + H]+ Calcd for C28H27O5 443.1853; found: 443.1857.
Diethyl 2–benzoyl–5–thiophen–2–yl–cyclopent–2–ene–1,1–dicarboxylate (5f): Brown liquid;
1
Yield: 300 mg (75%); H NMR (400 MHz, CDCl3):
δ
7.91 (d,
= 4.8 Hz, 1H), 7.10 (d,
= 8.0 Hz, 1H), 4.29–4.21 (s, 2H), 3.91 (q,
J
= 7.6 Hz, 2H), 7.55 (q,
= 2.8 Hz, 1H), 6.94 (t,
= 6.8, 2H), 3.92
= 7.2 Hz, 3H), 0.99 (t,
192.1, 170.2, 167.9, 143.9, 142.6, 141.7,
J = 7.2
Hz, 1H), 7.45 (t,
J
= 7.2 Hz, 2H), 7.18 (d,
J
J
J =
5.2 Hz, 1H), 6.56 (s, 1H), 4.50 (t,
J
J
(q,
J
= 6.8 Hz, 1H), 3.08 (ddd,
J
= 18.4, 6.4, 2.0, Hz, 1H), 1.19 (t,
J
J =
7.2 Hz, 3H) ppm; 13C NMR (100 MHz, CDCl3):
δ
137.3, 132.8, 129.5, 128.4, 126.7, 124.4, 72.0, 62.9, 61.4, 46.8, 40.6, 13.9, 13.7 ppm; HRMS
(ESIꢀTOF) m/z: [M + H]+ Calcd for C22H23O5S 399.1261; found: 399.1265.
Diethyl 2–(4–methylbenzoyl)–5–phenyl–cyclopent–2–ene–1,1–dicarboxylate (5g): Yellow
liquid; Yield: 366 mg (90%); 1H NMR (400 MHz, CDCl3):
7.6 Hz, 2H), 7.31–7.24 (m, 5H), 6.63 (s, 1H), 4.28–4.22 (m, 3H), 3.82–3.62 (m, 2H), 3.19 (ddd,
= 18.4, 8.4, 2.4, Hz, 1H), 3.04 (ddd, = 18, 6.8, 2.0, Hz, 1H) 2.42 (s, 3H), 1.21 (t, = 7.2 Hz,
δ 7.82 (d, J = 8 Hz, 2H), 7.38 (d, J =
J
J
J
ACS Paragon Plus Environment

Page 19 of 28
The Journal of Organic Chemistry
1
2
3
4
13
3H), 0.86 (t,
J
= 7.0 Hz, 3H) ppm; C NMR (100 MHz, CDCl3):
δ
192.0, 170.8, 168.2, 144.5,
5
6
7
8
143.4, 142.6, 139.8, 135.0, 129.6, 129.1, 128.8, 128.1, 127.3, 72.4, 61.8, 61.2, 51.5, 39.9, 21.7,
13.9, 13.5 ppm; HRMS (ESIꢀTOF) m/z: [M + H]+ Calcd for C25H27O5 407.1853; found:
407.1860.
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Diethyl 2–(4–chlorobenzoyl)–5–phenyl–cyclopent–2–ene–1,1–dicarboxylate (5h): Yellow
liquid; Yield: 328 mg (77%); 1H NMR (400 MHz, CDCl3):
δ 7.86 (q, J = 4.8 Hz, 2H), 7.45 (q, J
= 5.2 Hz, 2H), 7.38–7.25 (m, 5H), 6.64 (t, = 2.6 Hz, 1H), 4.28–4.23 (m, 3H), 3.82–3.66 (m,
J
2H), 3.21 (ddd,
J
= 18.4, 8.8, 2.8, Hz, 1H), 3.05 (ddd,
J
= 18.4, 6.8, 2.8, Hz, 1H), 1.23 (t,
J =
13
7.2 Hz, 3H), 0.87 (t,
J
= 7.0 Hz, 3H) ppm; C NMR (100 MHz, CDCl3):
δ
191.0 170.6, 168.0,
145.1, 142.4, 137.0, 136.0, 128.7, 128.7, 128.1, 127.4, 126.0, 72.5, 61.9, 61.2, 51.6, 40.0, 13.9,
13.5 ppm; HRMS (ESIꢀTOF) m/z: [M + H]+ Calcd for C24H24ClO5 427.1307; found: 427.1310.
Diethyl 2–(4–nitrobenzoyl)–5–phenyl–cyclopent–2–ene–1,1–dicarboxylate (5i): Brown
liquid; Yield: 292 mg (67 %); 1H NMR (400 MHz, CDCl3):
δ 8.34 (d, J = 8.8 Hz, 2H), 8.05 (d, J
= 8.4 Hz, 2H), 7.37–7.27 (m, 4H), 6.71 (t, = 2.4 Hz, 1H), 4.31–4.26 (m, 4H), 3.83–3.66 (m,
J
2H), 3.25 (ddd,
J
= 18.8, 8.4, 2.4, Hz, 1H), 3.08 (ddd,
J
= 18.4, 6.4, 2.0, Hz, 1H), 1.26 (t,
J
= 7.2
Hz, 3H), 0.88 (t,
J
= 7.2 Hz, 3H) ppm; 13C NMR (100 MHz, CDCl3):
δ 190.5, 170.5, 168.0,
150.1, 147.0, 142.7, 142.5, 139.4, 130.3, 128.7, 128.2, 127.6, 123.7, 72.4, 62.1, 61.4, 51.7, 40.3,
14.0, 13.5 ppm; HRMS (ESIꢀTOF) m/z: [M + Na]+ Calcd for C24H23NO7Na 460.1367; found:
460.1373.
Diethyl 2–(4–methylbenzoyl)–5–p–tolyl–cyclopent–2–ene–1,1–dicarboxylate (5j): Pale
1
yellow liquid; Yield: 332 mg (79%); H NMR (400 MHz, CDCl3):
δ
7.82 (d,
J = 7.6 Hz, 2H),
7.26 (t,
J
= 8.4 Hz, 4H), 7.10 (d,
J
= 7.6 Hz, 2H), 6.60 (s, 1H), 4.22 (d,
J
= 7.2, 3H), 3.83–3.69
ACS Paragon Plus Environment

The Journal of Organic Chemistry
Page 20 of 28
1
2
3
4
5
6
7
8
9
(m, 2H), 3.76 (ddd,
(s, 3H), 2.30 (s, 3H), 1.19 (t,
MHz, CDCl3):
J
= 34.4, 17.2, 10.0, Hz, 1H), 3.07(ddd,
J
= 51.6, 18.0, 8.4, Hz, 1H), 2.39
J
= 7.0 Hz, 3H), 0.90 (t,
J
= 7.2 Hz, 3H) ppm; 13C NMR (100
δ
192.0, 170.8, 168.2, 144.6, 143.4 142.6, 136.9, 136.6, 135.0 129.6, 129.1,
128.8, 128.7, 72.3, 61.7, 61.1, 39.9, 21.6, 21.1, 13.9, 13.6 ppm; HRMS (ESIꢀTOF) m/z: [M + H]+
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Calcd for C26H29O5 421.2010; found: 421.2015.
Diethyl 2–(4–chlorobenzoyl)–5–p–tolyl–cyclopent–2–ene–1,1–dicarboxylate (5k): Yellow
liquid; Yield: 336 mg (76%); 1H NMR (400 MHz, CDCl3):
= 8.0 Hz, 2H), 7.25 (d, = 8.0 Hz, 2H), 7.10 (d, = 7.6 Hz, 2H), 6.63 (s, 1H), 4.27–4.20 (m,
3H), 3.85–3.70 (m, 2H), 3.17 (ddd, = 18.4, 8.4, 1.2 Hz, 1H), 3.06–3.0 (m, 1H), 2.32 (s, 3H),
1.22 (t, = 7.2 Hz, 3H), 0.91(t, δ 191.1
= 7.2 Hz, 3H) ppm; 13C NMR (100 MHz, CDCl3):
δ 7.85 (d, J = 8.0 Hz, 2H), 7.45 (d, J
J
J
J
J
J
170.6, 168.1, 145.3, 142.4, 139.0, 137.0, 136.4, 136.0, 130.9, 128.9, 128.7, 128.6, 72.3, 61.9,
61.3, 51.3, 21.1,40.0, 13.9, 13.6 ppm; HRMS (ESIꢀTOF) m/z: [M + H]+ Calcd for C25H26ClO5
441.1463; found: 441.1467.
Diethyl 2–(4–chlorobenzoyl)–5–thiophen–2–yl–cyclopent–2–ene–1,1–dicarboxylate (5l):
ο
Yellow solid; Yield: 306 mg (71%); 105ꢀ107 C; 1H NMR (400 MHz, CDCl3):
δ
7.87 (d,
= 4.8 Hz, 1H), 7.11 (s, 1H), 6.97 (t, = 4.4 Hz,
= 8.0, 1H), 4.27 (q, = 7.2, 2H), 3.97–3.90 (s, 2H), 3.95–3.89 (m,
= 7.2 Hz, 3H), 1.01 (t, = 7.2 Hz, 3H)
190.9, 170.2, 167.8, 143.9, 142.3, 141.6, 139.2, 135.6,
J = 8.0
Hz, 2H), 7.46 (d,
J
= 8.4 Hz, 2H), 7.21 (d,
J
J
1H), 6.59 (s, 1H), 4.51(t,
J
J
Hz, 1H), 3.21 (ddd,
J
= 24.4, 16.4, 8.4, Hz, 1H), 1.24 (t,
J
J
ppm; 13C NMR (100 MHz, CDCl3):
δ
130.9, 128.8, 126.7, 126.6, 72.1, 62.0, 61.6, 46.8, 40.7, 13.9, 13.6 ppm; HRMS (ESIꢀTOF) m/z
:
[M + Na]+ Calcd for C22H21ClO5NaS 455.0690; found: 455.0696.
ACS Paragon Plus Environment

Page 21 of 28
The Journal of Organic Chemistry
1
2
3
4
5
6
7
8
9
(E,E)-Diethyl 2–(1–benzoyl–5–phenyl–penta–2,4–dienyl)–dicarboxylate
(
6a): Yellow liquid;
= 7.4
= 14.4 Hz, 1H), 5.10 (s, 1H),
196.4,
1
Yield: 336 mg (86%); H NMR (400 MHz, CDCl3):
δ 7.71 (d, J = 7.2 Hz, 2H), 7.56 (t, J
Hz, 1H), 7.47 (t,
4.27 (q,
J
= 8.0 Hz, 4H), 7.37–7.12 (m, 5H), 6.85 (d, J
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
13
J
= 7.2 Hz, 4H), 1.28 (t,
J
= 7.2 Hz, 6H) ppm; C NMR (100 MHz, CDCl3):
δ
168.0, 145.9, 142.8, 138.0, 135.9, 131.8, 131.7, 129.5, 128.9, 128.3, 127.5, 123.3, 61.9, 50.6,
14.1 ppm; HRMS (ESIꢀTOF) m/z: [M + H]+ Calcd for C24H25O5 393.1697; found: 393.1702.
(E,E)-Diethyl 2–[1–benzoyl–5–(4–methoxy–phenyl)–penta–2,4–dienyl]–dicarboxylate (6b):
1
Yellow liquid; Yield: 338 g (80%); H NMR (400 MHz, CDCl3):
δ
7.70, (d,
= 8.8 Hz, 2H), 6.80
= 6.8 Hz, 4H), 3.80 (s, 3H), 1.27 (t, = 7.2 Hz,
196.3, 168.2, 146.8, 142.8, 138.3, 131.6, 130.7, 129.4,
J = 6.8 Hz, 2H),
7.53 (t,
J = 7.4 Hz, 1H), 7.47–7.39 (m, 4H), 7.15–7.03 (m, 2H), 6.87 (d, J
(d,
J
= 14.8 Hz, 1H), 5.10 (s, 1H), 4.26 (q,
J
J
6H) ppm; 13C NMR (100 MHz, CDCl3):
δ
129.2, 128.7, 128.3, 121.2, 114.4, 61.9, 55.4, 50.6, 14.1 ppm; HRMS (ESIꢀion trap) m/z: [M +
Na]+ Calcd for C25H26O6Na 445.1622; found: 445.1621.
(E,E)-Diethyl 2–[1–benzoyl–5–(4–chlorophenyl)–penta–2,4–dienyl]–dicarboxylate (6c): Pale
1
yellow liquid; Yield: 316 mg (74%); H NMR (400 MHz, CDCl3):
δ 7.68–7.66 (m, 2H), 7.47–
7.44 (m, 4H), 7.39 (m, 3H), 7.17 (d,
14.8, 1H), 5.05 (s, 1H), 4.27 (q, = 7.2 Hz, 4H), 1.28 (t,
MHz, CDCl3):
J
= 14.8 Hz, 1H), 7.08 (d,
J
= 11.6 Hz, 1H), 6.88 (d, J =
13
J
J
= 7.2 Hz, 6H) ppm; C NMR (100
δ
195.2, 167.9, 145.9, 143.2, 138.2, 136.3, 135.8, 131.6, 130.9, 129.7, 129.0,
128.7, 127.6, 123.1, 62.1, 50.7, 14.1 ppm; HRMS (ESIꢀTOF) m/z: [M + H]+ Calcd for
C24H24ClO5 427.1307; found: 427.1315.
ACS Paragon Plus Environment

The Journal of Organic Chemistry
Page 22 of 28
1
2
3
4
(E,E)-Diethyl
2–[1–benzoyl–5–(4–nitrophenyl)–penta–2,4–dienyl]–dicarboxylate
(6d):
5
6
7
8
Yellow solid; Yield: 348 mg (80%); 128–130 οC; 1H NMR (400 MHz, CDCl3):
Hz, 2H), 7.73 (d,
δ
8.21 (d,
J
= 7.2
J
= 8.0, 2H), 7.61–7.57 (m, 3H), 7.51–7.47 (m, 2H), 7.41–7.34 (m, 1H), 7.12
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
(d,
J
= 11.2 Hz, 1H), 6.88 (d,
J
= 15.6 Hz, 1H), 5.13 (s, 1H), 4.28 (q,
J
= 7.2 Hz, 4H), 1.29 (t,
J =
7.0 Hz, 6H) ppm; 13C NMR (100 MHz, CDCl3):
δ
196.2, 167.8, 147.8, 144.2, 142.1, 139.1,
137.5, 134.1, 132.2, 129.6, 128.4, 127.9, 127.6, 124.3, 62.2, 50.8, 14.1 ppm; HRMS (ESIꢀion
trap) m/z: [M]+ Calcd for C24H23NO7 437.1475; found: 437.1473.
(E,E)-Diethyl 2–(1–benzoyl–5–naphthalen–2–yl–penta–2,4–dienyl)–dicarboxylate (6e):
1
Dark brown liquid; Yield: 310 mg (70%); H NMR (400 MHz, CDCl3):
δ 7.78–7.74 (m, 2H),
7.57–7.54 (m, 1H), 7.48–7.44 (m, 5H), 7.37–7.31 (m, 3H), 7.26–7.12 (m, 3H), 6.85 (d,
J = 14.4
13
Hz, 1H), 5.10 (s, 1H), 4.27 (d,
MHz, CDCl3):
J
= 7.2 Hz, 4H), 1.28 (t,
J
= 7.2 Hz, 6H) ppm; C NMR (100
δ
196.4, 168.1, 146.0, 142.8, 138.0, 135.9, 131.9, 131.8, 129.6, 129.5, 128.9,
128.3, 127.6, 123.3, 62.0, 50.7, 14.1 ppm; HRMS (ESIꢀion trap) m/z: [M + H]+ Calcd for
C28H27O5 443.1853; found: 443.1851.
(E,E)-Diethyl
2–(1–benzoyl–5–thiophen–2–yl–penta–2,4–dienyl)–dicarboxylate
(6f):
Colorless liquid; Yield: 306 mg (77%); 1H NMR (400 MHz, CDCl3):
δ
7.69 (d, J = 6.8 Hz, 2H),
7.55–7.52 (m, 1H), 7.47–7.43 (m, 2H), 7.31 (d,
4.29–4.24 (m, 4H), 1.28 (t,
J
= 4.8 Hz, 1H), 7.11–6.94 (m, 5H), 5.05 (s, 1H),
13
J
= 7.2 Hz, 6H) ppm; C NMR (100 MHz, CDCl3):
δ
196.2, 167.9,
145.6, 141.4, 138.0, 135.2, 131.8, 131.5, 129.57, 129.52, 129.41, 129.37, 129.1, 128.3, 128.2,
127.8, 122.6, 62.0, 50.7, 14.1 ppm; HRMS (ESIꢀTOF) m/z: [M + H]+ Calcd for C22H23O5S
399.1261; found: 399.1263.
ACS Paragon Plus Environment

Page 23 of 28
The Journal of Organic Chemistry
1
2
3
4
(E,E)-Diethyl 2–[1–(4–methylbenzoyl)–5–phenyl–penta–2,4–dienyl]–dicarboxylate (6g):
5
6
1
Yellow liquid; Yield: 332 mg (82%); H NMR (400 MHz, CDCl3):
δ 7.63 (d, J = 8.0 Hz, 2H),
7
8
9
7.45 (d,
J
= 6.8 Hz, 2H), 7.37–7.11 (m, 7H), 6.84 (d,
J
= 14.4 Hz, 1H), 5.08 (s, 1H), 4.26 (q, J =
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
13
7.2 Hz, 4H), 2.43 (s, 3H), 1.27 (t,
J
= 7.2 Hz, 6H) ppm; C NMR (100 MHz, CDCl3):
δ
196.2,
168.1, 145.3, 142.5, 142.4, 136.0, 135.2, 131.9, 129.7, 129.5, 129.0, 128.9, 127.5, 123.4, 61.9,
50.8, 21.6, 14.1 ppm; HRMS (ESIꢀTOF) m/z: [M + H]+ Calcd for C25H27O5 407.1853; found:
407.1854.
(E,E)-Diethyl 2–[1–(4–chlorobenzoyl)–5–phenyl–penta–2,4–dienyl]–dicarboxylate (6h):
Colorless liquid; Yield: 320 mg (75%); 1H NMR (400 MHz, CDCl3):
δ 7.67 (d, J = 8.4 Hz, 2H),
7.47–7.44 (m, 4H), 7.39–7.33 (m, 3H), 7.16 (d,
(d, = 15.2 Hz, 1H), 5.05 (s, 1H), 4.27 (q,
NMR (100 MHz, CDCl3):
J
= 11.2 Hz, 1H), 7.08 (d,
J
= 11.2 Hz, 1H), 6.87
13
J
J
= 7.2 Hz, 4H), 1.28 (t,
J
= 7.2 Hz, 6H) ppm; C
δ
195.1, 167.9, 145.8, 143.1, 138.2, 136.3, 135.8, 131.6, 130.9, 129.7,
129.0, 128.9, 128.8, 128.6, 127.6, 123.1, 62.0, 50.7, 14.1 ppm; HRMS (ESIꢀTOF) m/z: [M + H]+
Calcd for C24H24ClO5 427.1307; found: 427. 1312.
(E,E)-Diethyl 2–[1–(4–nitrobenzoyl)–5–phenyl–penta–2,4–dienyl]–dicarboxylate (6i): Pale
1
Yellow liquid; Yield: 276 mg (63%); H NMR (400 MHz, CDCl3):
δ 8.33 (d, J = 8.8 Hz, 2H)
7.84 (d,
J = 8.8 Hz, 2H), 7.47 (q, J = 6.0 Hz, 2H), 7.40–7.36 (m, 3H), 7.23–7.16 (m, 1H), 7.06
(d,
J = 11.2 Hz, 1H), 6.89 (d, J = 15.2 Hz, 1H), 5.09 (s, 1H), 4.29 (q, J = 5.6 Hz, 4H), 1.30 (t, J =
7.0 Hz, 6H) ppm; 13C NMR (100 MHz, CDCl3):
δ
194.5, 167.7, 149. 5, 147.3, 144.3 143.7,
135.6, 131.5, 130.1, 130.0, 129.0, 127.7, 123.6, 122.8, 62.1, 50.3, 14.1 ppm; HRMS (ESIꢀion
trap) m/z: [M + Na]+ Calcd for C24H23NO7Na 460.1367; found: 460.1369.
ACS Paragon Plus Environment

The Journal of Organic Chemistry
Page 24 of 28
1
2
3
4
(E,E)-Diethyl 2–[1–(4–methylbenzoyl)–5–p–toyl–penta–2,4–dienyl]–dicarboxylate (6j):
5
6
7
8
1
Yellow liquid; Yield: 296 mg (70%); H NMR (400 MHz, CDCl3):
δ
7.63 (d,
= 6.4 Hz, 4H), 6.82 (q,
= 7.2 Hz, 6H)
196.2, 168.2, 145.8, 142.6, 142.4, 139.9, 135.3, 133.3,
J
= 8.0 Hz, 2H),
7.35 (d,
J
= 8.0 Hz, 2H), 7.26 (d,
J
= 7.6 Hz, 2H), 7.14 (q,
J
J
= 6.4 Hz,
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
1H), 5.07 (s, 1H), 4.26 (q,
J = 7.2 Hz, 4H), 2.43 (s, 3H), 2.35 (s, 3H), 1.27 (t, J
ppm; 13C NMR (100 MHz, CDCl3):
δ
131.4, 129.7, 129.6, 129.0, 127.5, 122.4, 61.9, 50.8, 21.6, 14.1 ppm; HRMS (ESIꢀTOF) m/z: [M
+ H]+ Calcd for C26H29O5 421.2010; found: 421.2014.
Synthesis of diethyl 2–benzoyl–5–phenyl–cyclopentane–1,1–dicarboxylate (11): To a
solution of cyclopentene 5a (98 mg; 0.25 mmol) in MeOH (5 mL) was added 5% Pd/C (53 mg;
10 mol%) and hydrogen gas was bubbled through the reaction mixture for 5 min. The reaction
was stirred at room temperature under hydrogen atmosphere (balloon pressure) for 10 h. After
the reaction was complete, the reaction mixture was filtered using celite and the filtrate was
concentrated under reduced pressure. The residue was purified by column chromatography using
ethyl acetate/hexane (1:9) to give 11 as a mixture of diastereomers. Pale yellow liquid; Yield: 84
mg (85%). HRMS (ESIꢀion trap) m/z: [M + Na]+ Calcd for C24H26O5Na 417.1672; found:
417.1670. The diastereomers were separated by repeated column chromatography. Major
diastereomer: 1H NMR (500 MHz, CDCl3):
7.43 q, = 7.2 Hz, 4H), 7.26–7.19 (m, 3H), 4.40 (t,
3.92(m, 2H), 3.83 (q, = 1.6 Hz, 1H), 2.63 (q, = 4.8 Hz, 1H), 2.42 (q,
= 3.6 Hz, 2H), 1.09 (t, = 5.6 Hz, 3H), 1.01 (t,
δ
8.00 (d,
J
= 6.4 Hz, 2H), 7.53
(t, J = 5.8 Hz, 1H),
(
J
J = 7.2 Hz, 1H), 4.16–4.08 (m, 2H), 4.00–
J
J
J
= 7.2 Hz, 1H), 2.28 (q,
13
J
J
J
= 5.6 Hz, 3H) ppm; C NMR (125 MHz,
CDCl3):
δ 198.5, 171.4, 169.1, 139.1, 137.1, 132.9, 129.6, 128.5, 128.4, 127.7, 127.0, 67.2, 61.4,
60.9, 55.5, 52.7, 31.4, 28.3. 13.81, 13.7 ppm; Minor diastereomer: 1H NMR (500 MHz,
CDCl3): 8.00 (d, = 6.4 Hz, 2H), 7.57 t, = 5.8 Hz, 1H), 7.47 t, = 6.2 Hz, 2H), 7.19 (t,
δ
J
(
J
(
J
J =
ACS Paragon Plus Environment

Page 25 of 28
The Journal of Organic Chemistry
1
2
3
4
5
6
7
8
9
6.0 Hz, 2H), 7.12 (t,
4.0 Hz, 2H), 1.68–1.40 (m, 6H), 1.26 (t,
(125 MHz, CDCl3):
J
= 5.8 Hz, 1H), 7.00 (d,
J
= 6.0 Hz, 1H), 4.26
–
4.03 (m, 6H), 2.48 (q,
J =
J
= 5.6 Hz, 3H), 1.23 (t,
J
= 5.6 Hz, 3H) ppm; 13C NMR
δ
201.8, 168.8, 168.4, 141.4, 137.0, 133.2, 128.7, 128.5, 128.3, 125.8, 61.73,
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61.67, 54.0, 44.8, 35.7, 30.2, 27.5, 14.1, 13.9 ppm.
Synthesis of diethyl 5–benzoyl–4–chloro–2–(4–methoxyphenyl)–cyclopent–2–ene–1,1–
dicarboxylate (12): To a solution of diene 6b (106 mg; 0.25 mmol) in dichloromethane (5 mL)
was added SnCl4 (30 µL; 0.25 mmol) at room temperature. The reaction mixture was stirred at
room temperature and monitored by TLC. After the reaction was complete, the reaction mixture
was quenched with ice–water and extracted with dichloromethane. The combined organic layers
were washed with brine, dried over anhydrous Na2SO4 and evaporated under vacuum. The crude
product was purified by column chromatography on silica gel using ethyl acetate/hexane (1:9) as
the eluent to give pure 12. Pale yellow liquid; Yield: 88 mg (77%); 1H NMR (400 MHz, CDCl3):
δ
7.95 (d,
J
= 7.2 Hz, 2H), 7.94–7.60 (m, 1H), 7.51 (t,
= 8.8 Hz, 2H), 6.52 (d, = 2.0 Hz, 1H), 5.43 (q,
= 7.0, 2H), 3.81 (s, 3H), 1.11 (t, = 7.2 Hz, 3H), 1.03 (t,
191.3, 168.9, 167.4, 159.4, 142.3, 142.1, 136.5, 133.4, 130.6, 129.6,
J
= 7.6 Hz, 2H), 7.38 (d,
J = 8.8 Hz, 2H),
6.89 (d,
4.00 (t,
J
J
J
= 6.0 Hz, 1H), 4.24–4.16 (m, 3H),
13
J
J
J = 7.0 Hz, 3H) ppm; C
NMR (100 MHz, CDCl3):
δ
128.6, 126.2, 113.7, 71.5, 64.4, 62.1, 60.5, 55.3, 13.74, 13.70 ppm; HRMS (ESIꢀion trap) m/z
:
[M + H]+ Calcd for C25H26ClO6 457.1412; found: 457.1411.
ASSOCIATED CONTENT
Supporting Information
ACS Paragon Plus Environment

The Journal of Organic Chemistry
Page 26 of 28
1
2
3
1
13
Copies of H and C NMR spectra for all products and Xꢀray structural information for 5l and
6d (CIF). This material is available free of charge via the Internet at http://pubs.acs.org.
AUTHOR INFORMATION
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Corresponding author
* Fax: +91ꢀ431ꢀ2407043. Tel: +91ꢀ431ꢀ2407053. Eꢀmail: srinivasank@bdu.ac.in
Notes
The authors declare no competing financial interest.
ACKNOWLEDGMENTS
The authors thank Science and Engineering Research Board (SERB), India for financial support
and DSTꢀFIST for instrumentation facilities at School of Chemistry, Bharathidasan University.
M.T. thanks the University Grants Commission (UGC) for a BSRꢀRFSMS fellowship.
NOTES AND REFERENCES
(1) (a) Reissig, H.ꢀU.; Zimmer, R. Chem
Tetrahedron 2005 61, 321. (c) Melnikov, M. Y.; Budynina, E. M.; Ivanova, O. A.; Trushkov, I.
V. Mendeleev Commun 2011 21, 293. (d) Schneider, T. F.; Kaschel, J.; Werz, D. B. Angew
Chem., Int Ed 2014 53, 5504. (e) de Nanteuil, F.; De Simone, F.; Frei, R.; Benfatti, F.; Serrano,
E.; Waser, J. Chem Commun 2014 50, 10912. (f) Grover, H. K.; Emmett, M. R.; Kerr, M. A.
Org Biomol Chem 2015 13, 655.
. Rev. 2003, 103, 1151. (b) Yu, M.; Pagenkopf, B. L.
,
.
,
.
.
.
,
.
.
,
.
.
.
,
(2) (a) Qu, J.ꢀP.; Liang, Y.; Xu, H.; Sun, X.ꢀL.; Yu, Z.ꢀX.; Tang, Y. Chem. Eur. J. 2012
, 18,
2196. (b) Cavitt, M. A.; Phun, L. H.; France, S. Chem Soc Rev 2014 43, 804. (c) Zhu, J.;
.
.
.
,
Liang, Y.; Wang, L.; Zheng, Z.ꢀB.; Houk, K. N.; Tang, Y. J. Am. Chem. Soc. 2014, 136, 6900.
ACS Paragon Plus Environment

Page 27 of 28
The Journal of Organic Chemistry
1
2
3
4
5
6
(d) Xu, H.; Hu, J.ꢀL.; Wang, L.; Liao, S.; Tang, Y. J. Am. Chem. Soc. 2015
,
137, 8006. (e) Wang,
Chem.
L.; Tang, Y. Isr. J. Chem. 2016
,
56, 463. (f) Martin, M. C.; Shenje, R.; France, S. Isr
.
J.
7
8
9
2016
2017
,
,
56, 499. (g) Budynina. E. M.; Ivanov. K. L.; Sorokin. I. D.; Melnikov. M. Y. Synthesis
49, 3035.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
(3) Sathishkannan, G.; Srinivasan, K. Adv. Synth. Catal. 2014, 356, 729.
(4) Hudlicky, T.; Reed, J. W. Angew
.
Chem., Int
.
Ed
.
2010
,
49, 4864.
(5) (a) Perez, L. J.; Shimp, H. L.; Micalizio, G. C.
J.
Org
.
Chem
.
2009
,
74, 7211. (b) Hao, Z. Y.;
Liang, D.; Luo, H.; Liu, Y. F.; Ni, G.; Zhang, Q. J.; Li, L.; Si, Y. K.; Sun, H.; Chen, R. Y.; Yu,
D. Q. Nat Prod 2012 75, 1083. (c) Reddy, C. R.; Kumaraswamy, P. RSC Adv 2014 , 7035.
(d) Nord, C.; Menkis, A.; Broberg, A. Nat Prod 2015 78, 2559.
J.
.
.
,
.
, 4
J.
.
.
,
(6) (a) Kobayashi, Y.; Nakata, K.; Ainai, T. Org
Wang, Q.; Zhu, J. Angew Chem., Int Ed 2016 55, 760. (c) Wetzel, A.; Bergman, J.; Brandt, P.;
Larhed, M.; Branalt, J. Org Lett 2017 19, 1602.
. Lett. 2005, 7, 183. (b) Dagoneau, D.; Xu, Z.;
.
.
.
,
.
.
,
(7) (a) Larsen, S. D.; Fisher, P. V.; Libby, B. E.; Jensen, R. M.; Mizsak, S. A.; Watt, W.; Ronk,
W. R.; Hill, S. T. Org Chem 1996 61, 4725. (b) Bohn, M. A.; Schmidt, A.; Hilt, G.;
Dindaroglu, M.; Schmalz, H.ꢀG. Angew Chem., Int Ed 2011 50, 9689. (c) Saito, N.;
Kobayashi, A.; Sato, Y. Angew Chem., Int Ed 2012 51, 1228.
J.
.
.
,
.
.
.
,
.
.
.
,
(8) (a) Chiang, P. C.; Kaeobamrung, J.; Bode, J. W.
Kohn, B. L.; Jarvo, E. R. Org Lett 2011 13, 4858. (c) Peng, J.; Chen, C.; Chen, J.; Su, X.; Xi,
C.; Chen, H. Org Lett 2014 16, 3776. (d) Mondal, S.; Yetra, S. R.; Patra, A.; Kunte, S. S.;
Gonnade, R. G.; Biju, A. T. Chem Commun 2014 50, 14539. (e) Liang, Y.; Lai, J.; Liu, T.;
J. Am. Chem. Soc. 2007, 129, 3520. (b)
.
.
,
.
.
,
.
.
,
ACS Paragon Plus Environment

The Journal of Organic Chemistry
Page 28 of 28
1
2
3
4
Tang, S. Org
.
Lett., 2016
,
18, 5086. (f) Llpez. E.; Llpez. L.A. Angew. Chem., Int. Ed. 2017, 56,
5
6
5121.
7
8
9
(9) (a) Mundal, D. A.; Lutz, K. E.; Thomson, R.
P.; Somfai, P. Org Chem 2011 76, 8070. (c) Billard, F.; Robiette, R.; Pospisil, J.
Chem 2012 77, 6358. (d) Xiao, Q.; Wang, B.; Tian, L.; Yang, Y.; Ma, J.; Zhang, Y.; Chen, S.;
Wang, J. Angew Chem., Int Ed 2013 52, 9305. (e) Wang, Z.ꢀX.; Wang, Y.ꢀZ.; Zhang, L.ꢀM.
Am Chem Soc 2014 136, 8887. (f) de Orbe, M. E.; Amenós, L.; Kirillova, M S.; Wang, Y.;
LópezꢀCarrillo, V.; Maseras, F.; Echavarren, A. M. Am Chem Soc 2017 139, 10311.
J
.
Org
.
Lett
.
2009
,
11, 465. (b) Borg, T.; Tuzina,
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
J
.
.
.
,
J.
Org.
.
,
.
.
.
,
J.
.
.
.
,
J.
.
.
.
,
(10) (a) Sathishkannan, G.; Srinivasan, K. Org
Org Chem 2014 79, 3653.
. Lett. 2011, 13, 6002. (b) Selvi, T.; Srinivasan, K.
J.
.
.
,
(11) Saidi, M. R.; Azizi, N.; Akbari, E.; Ebrahimi, F. J. Mol. Catal. A: Chem. 2008, 292, 44.
(12) (a) Frontier, A. J.; Collison, C. Tetrahedron 2005
West, F. G.; Chem. Commun. 2009, 5676. (c) Vinogradov, M. G.; Turova, O. V.; Zlotin, S. G.
Org. Biomol. Chem. 2017 15, 8245.
, 61, 7577. (b) Grant, T. N.; Rieder, C. J.;
,
(13) CCDC 1573672 for compound 5l. See the Supporting Information for details.
(14) CCDC 1573675 for compound 6d. See the Supporting Information for details.
ACS Paragon Plus Environment