Ruthenium Catalyzed Rearrangement of Ene-cyclopropenes. Divergent Reaction Pathways

Article abstract of DOI:10.1021/acs.joc.8b02849

The reaction of ene-cyclopropenes with Cp?RuCl(cod) leads to alkenyl bicyclo[3.1.0]hexanes, bicyclo[4.1.0]heptanes, and bicyclo[5.1.0]octanes. This reaction involves a reverse regioselectivity in the cyclopropene opening than with gold chlorides. With gem

Full text of DOI:10.1021/acs.joc.8b02849

Article
pubs.acs.org/joc
Cite This: J. Org. Chem. 2019, 84, 924−933
Ruthenium Catalyzed Rearrangement of Ene-cyclopropenes.
Divergent Reaction Pathways
́
́
Alberto Lopez-Rodríguez, Gema Domínguez, and Javier Perez-Castells*
Facultad de Farmacia, Dpto. Química y Bioquímica, Universidad San Pablo CEU, Urb. Montepríncipe, Boadilla del Monte, 28668
Madrid, Spain
S
* Supporting Information
ABSTRACT: The reaction of ene-cyclopropenes with Cp*RuCl(cod) leads to alkenyl bicyclo[3.1.0]hexanes, bicyclo[4.1.0]-
heptanes, and bicyclo[5.1.0]octanes. This reaction involves a reverse regioselectivity in the cyclopropene opening than with gold
chlorides. With gem-disubstituted cyclopropenes, a novel cycloisomerization based on ring-opening nucleophilic attack and
rearrangement is observed. Alternatively, some gem-disubstituted cyclopropenes give dimerizations of the intermediate carbene.
Scheme 1. Regioselectivity in Ene-cyclopropene
Rearrangements
INTRODUCTION
■
Cyclopropenes are highly strained compounds and therefore
are reactive molecules that undergo a wide variety of
interesting transformations.1 They behave in some cases as
typical olefins, but in many ways, they share characteristics of
alkynes. Thus, the C−H bonds of the vinylic carbons are
similar to those of terminal alkynes. This increased π-density of
its double bond facilitates the coordination with π-philic
transition metals including those with high alkynophilicity.
This paves the way for the development of different types of
rearrangements,2 additions,3 and cycloaddition reactions.4
After coordination of various metal complexes, ring-opening
of cyclopropenes can occur to generate organometallic species,
which are resonance hybrids of metal-stabilized allyl cations
and vinyl-metal carbenoids. The ring-opening can occur with
two possible regiochemistries. Allyl gold carbocations arising
from the ring-opening of cyclopropenes have shown to open
mainly to generate the terminal carbene.5 It has been
previously published that these carbenes can cyclopropanate
an alkene either inter-6 or intramolecularly (Scheme 1a).7 The
latter was disclosed by Cossy et al. starting from ene-
cyclopropenes where the cycloisomerization proceeded with
regioselective ring-opening of the cyclopropene. The reaction
gave access to 3-oxa- or 3-azabicyclo[4.1.0]heptanes. The
starting isopropenes invariably had a dimethyl substitution,
giving isopropylidene containing products.
products were previously described by Dixneuf et al. from
enynes where a mechanism based on metathesis was proposed
and supported by DFT calculations.9 The intermediate
carbene formed upon the cyclopropene opening gives the E-
alkenyl configuration and allows the extension of the method
to the synthesis of seven-membered rings. gem-Disubstituted
cyclopropenes produce novel polycyclic products or dimeriza-
tion of the intermediate carbene.
RESULTS AND DISCUSSION
■
Despite their high reactivity, cyclopropenes are readily
available and stable. The most general approach for the
synthesis of cyclopropenes involves the reaction of alkynes
Herein we show the reactivity of ene-cyclopropenes with
different substitution patterns both at the ring and at the
olefinic part using ruthenium catalysts. In the presence of
Cp*RuCl(cod),8 we show that the cyclopropene is opened
with the reverse regioselectivity with regard to gold catalysts
and gives alkenylbicyclo[n.1.0]alkanes (Scheme 1b). These
Received: November 7, 2018
Published: December 27, 2018
© 2018 American Chemical Society
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Table 1. Synthesis of Ene-cyclopropenes 3
a
prod·
X
R1
R2
R3
n
m
method
yield (%)
3a
3b
3c
3d
3e
3f
3g
3h
3i
3j
3k
3l
3m
3n
C(CO2Et)2
C(CO2Et)2
C(CO2Et)2
C(CO2Et)2
C(CO2Et)2
C(CO2Et)2
NTs
NTs
NTs
NTs
Me
H
H
H
H
H
H
Me
H
H
H
H
Me
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
Ph
Ph
Ph
Ph
1
1
1
2
1
1
1
1
1
1
1
1
1
1
1
1
1
1
2
3
1
1
2
3
1
1
1
3
B
A
A
B
B
B
A
A
A
A
C
C
C
C
73
84
71
67
61
48
64
71
66
52
67
89
81
41
C(CO2Et)2
C(CO2Et)2
C(CO2Et)2
C(CO2Et)2
H
Me
H
H
H
Me
H
H
a
In pure product.
Scheme 2. Gold Catalyzed Synthesis of 4a−b with Reaction Pathway
with metal carbenoids generated from diazocompounds.10 We
prepared some ene-cyclopropenes by cyclopropenation of
either enynes 1 or of alkynes which were further alkenylated
(Table 1). This latter procedure was used when the reaction of
the diazocompound with the enyne gave mixtures of
cyclopropene and cyclopropane products. For the synthesis
of products 3k−n, propargylmalonate was cyclopropenated,
and the resulting intermediate 2 was treated with different
alkenyl bromides. Overall, the yields were generally good
except with 4-pentenyl-containing substrates that gave
products 3f, 3j, and 3n in moderate yields.
Using ene-cyclopropenes 3a and 3g, we tested their
reactivity with three different catalytic systems. Both gold(I)
and (III) chlorides gave readily the reorganized bicyclo[4.1.0]
derivatives 4a−b in good yields (Scheme 2). This process
involves the coordination of gold with the cyclopropane
double bond, producing a carbocationic intermediate A which
evolves to the gold carbene B. The situation of the positive
charge in A at the most substituted carbon would explain the
preference of this metal to form the less substituted carbene
B.11 Further intramolecular cyclopropanation yields the final
products 4. This process was described by Cossy et al.,7 but in
their case, dimethyl substituted cyclopropene rings were always
used. Thus, we show that our ethoxycarbonylcyclopropene
systems give this transformation with total selectivity, as an
only isomer of the exocyclic olefin was isolated in good yields.
We used either AuCl or AuCl3 for this reaction under MW
heating at 100 °C for 60 min. The stereoselective outcome
would be a consequence of steric hindrance as in B′, which is
not present in B (Scheme 2). The cyclopropanation follows
through the chairlike transition state C. 4a−b were assigned
with NOESY experiments.
When using Cp*RuCl(cod), the process gave alkenylbicy-
clo[3.1.0]hexanes 5 with E-configuration. We optimized the
conditions for this transformation using substrate 3a as model
(Table 2). Initially, the reaction was tested at room
temperature, achieving poor conversions in long reaction
times (entries 1 and 2). Under refluxing toluene, it reached
total conversion but not good yields (entries 3 and 4). Thus,
we used microwave heating, and after tuning up the
temperature and reaction times (entries 5−10), we selected
as the best conditions for this rearrangement 100 °C in MW
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transition state G yields 5 (Scheme 3). Stereoselectivity of the
emerging double bond is explained following Dixneuf et al.9c
We understand that the intermediate F is common in the
process described by this group. The stereochemistry of the
double bond results from the electronic repulsion between the
chlorine and the ester groups which favors the opening that
lowers better the steric hindrance. This gives the alkenyl an E-
configuration.
Table 2. Reaction Conditions for the Transformation of 3a
into 5a
a
entry
temp (°C)
time (min)
conv
yield (%)
The reaction of 3k gave, initially, a total decomposition of
the starting material. Thus, we lowered the temperature to 50
°C, and we isolated 6a as the only reaction product in 64%
yield. We explain the formation of this structure in Scheme 3.
The presence of the phenyl group allowed the formation of
carbene F′ which is preferred to F in order to situate this large
group at a less hindered position. This arrangement allows the
nucleophilic attack of the carbonyl oxygen atom of the ester
group to deliver dioxacarbenium ion intermediate H. This type
of intermediate was proposed by Meyer et al. for a rhodium
catalyzed isomerization of cyclopropenylmethyl esters.12
Rearrangement of H into final products 6 would go through
transition state I and intermediate J. Only one isomer of 6 was
isolated, and it was assigned using NOE experiments. With
substrate 3l, the reaction at 50 °C gave, on the contrary, the
carbene dimer 7a. However, this substrate allowed heating the
process at 100 °C to give 6b in 69% yield. The intermediate
carbene dimerization was the only observed reaction with
substrates 3m−n under any reaction conditions, leading to
products 7b−c in high yields (Scheme 3).
1
2
3
4
5
6
7
8
9
RT
RT
Δ
Δ
45 (MW)
45 (MW)
80 (MW)
80 (MW)
100 (MW)
100 (MW)
100 (MW)
90
300
90
300
20
90
60
10
10
5
20
20
70
100
70
99
100
87
100
100
85
18
14
42
45
58
69
72
59
75
78
62
10
11
b
10
a
b
By NMR. 5 mol % of catalyst was used.
for 5 min, reaching total conversion and a 78% yield. Catalyst
loading was kept at 10 mol % as when using 5 mol % (entry
11) results were clearly lower.
These optimized conditions were applied to the whole array
of substrates with the results shown in Figure 1. The procedure
allows the formation of 5-, 6-, and 7-membered rings fused to
the cyclopropane, and yields were generally good. The
possibility of building seven-membered rings is interesting
and shows this is a wide scope process. On the contrary,
dimethyl substituted substrate 3c did not react under any
reaction conditions, not detecting the formation of the
expected product 5c. To our surprise, when using substrates
3k−l, gem-disubstituted at the cyclopropene, we isolated
products 6a−b.
CONCLUSIONS
■
In summary, we show a diverse reactivity of ene-cyclopropenes
under gold and ruthenium catalysis. The transformation of
compounds 3 into 5 is an interesting process, allowing the
synthesis of 5-, 6-, and 7-membered rings fused to cyclo-
propanes. The formation of compounds 6 is a novel process,
giving highly connected structures that we are currently
studying with more substrates.
This reaction involves the opening of the cyclopropene ring
with the reverse regioselectivity to give carbene F. Possibly the
initial coordination of the ruthenium with both double bonds
(D) explains the chemoselectivity as the bulky Cp* and Cl are
situated in a less crowded area. Oxidative cycloaddition to the
cyclopropane giving E, followed by cycloreversion, gives
carbene F. A final intramolecular cyclopropanation through
EXPERIMENTAL SECTION
General. All reactions promoted by microwaves were carried out
in an Initiator+ microwave reactor. Reaction progress was monitored
by H NMR spectra or using analytical thin-layer chromatography
(TLC) on silica gel 60 F-254 plate. Visualization was achieved by UV
light (254 nm). NMR spectra were recorded on a 400 MHz for H,
■
1
1
Figure 1. Structures and yields of compounds 5 and 6.
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Scheme 3. Reaction Pathways Leading to Products 5, 6, and 7
and 101 MHz for 13C spectrometer. Chemical shifts are reported in δ
ppm referenced to chloroform-d (δ 7.26 for 1H NMR and δ 77.16 for
13C NMR). All the residues were purified by flash chromatography on
2.7 Hz, 1H, CCH), 1.69 (s, 3H, CCH3), 1.66 (s, 3H, CCH3), 1.25
(t, J = 7.1 Hz, 6H, 2xCH2CH3).
4-Methyl-N-(pent-4-en-1-yl)-N-(prop-2-yn-1-yl)benzenesul-
fonamide, 1j. To a solution of 4-methyl-N-(prop-2-yn-1-yl)-
benzenesulfonamide (1.20 g, 5.73 mmol) in acetone (12.12 mL)
were added K2CO3 (960 mg, 6.88 mmol) and 5-bromo-1-pentene
(0.82 mL, 6.88 mmol) at 0 °C. Then, the mixture was stirred at reflux
overnight. Once TLC showed the completion of the reaction, it was
quenched with water (15 mL) and extracted with AcOEt (3 × 15
mL). The combined organic phases were then washed with brine (40
mL), dried over MgSO4, filtered, and concentrated under vacuum.
The titled compound was isolated as a colorless oil (1.38 g, 4.98
mmol, 73%) after filtration through a pad of silica plugged with
silica gel.
Compounds diethyl 2-(prop-2-yn-1-yl)malonate,13 diethyl 2-allyl-
2-(prop-2-yn-1-yl)malonate,14 1b, diethyl 2-(but-3-yn-1-yl)-
malonate,14 N-allyl-4-methyl-N-(prop-2-yn-1-yl)benzenesulfon-
amide,15 1g, 4-methyl-N-(2-methylallyl)-N-(prop-2-yn-1-yl)benzene-
sulfonamide,16 1h, and N-(but-3-en-1-yl)-4-methyl-N-(prop-2-yn-1-
yl)benzenesulfonamide,17 1i, were synthesized as described in the
literature.
General Procedure for Alkylation Reactions. To a stirred
solution of the starting material (1 equiv) in THF anh. (2.2 mL/
mmol was added NaH (1.2 equiv) in portions at 0 °C. Once the
addition was completed, the corresponding bromide (1.2 equiv) was
added slowly. After the addition was completed, the mixture was
allowed to warm up to room temperature and stirred until TLC
showed the reaction to be completed. The reaction was then
quenched with H2O (2 mL/mmol), extracted with AcOEt (3 × 2.5
mL/mmol), and the combined organic phases were washed with brine
(6 mL/mmol). The organic phase was then dried over MgSO4,
filtered, and concentrated under vacuum.
General Procedure for Cyclopropenation Reactions. To a
stirred suspension of Rh2(AcO)4 (0.01 equiv) in DCM anh. (60 mL/
mmol) was added a solution of the enyne 1 or the alkyne (1 equiv) in
DCM anh. (0.6 mL/mmol) at reflux. After the addition was
completed, a solution of the corresponding diazocompound (1.2
equiv. with enynes 1b−c, 1g−i (synthesis of 3b, 3c, 3g, 3h, 3i, 3j) or
2.5 equiv with diethyl 2-(prop-2-yn-1-yl)malonate or diethyl 2-(but-3-
yn-1-yl)malonate (synthesis of 3a, 3d, 3e, 3f, and 2) in DCM anh.
(0.8 mL/mmol) was added slowly (5 mL/h). After the addition was
completed, the mixture was stirred for another 30 min and then
filtrated through a pad of Celite. The filtrate was concentrated under
vacuum and purified by flash column chromatography.
1
Hexane/AcOEt (4:1). H NMR (400 MHz, CDCl3): δ 7.72 (d, J =
8.3 Hz, 2H, Ar), 7.29 (d, J = 8.0 Hz, 2H, Ar), 5.80 (ddt, J = 16.9, 10.2,
6.6 Hz, 1H, CHCH2), 5.08−4.96 (m, 2H, CHCH2), 4.13 (d, J =
2.4 Hz, 2H, NCH2C), 3.20 (t, J = 7.2 Hz, 2H, NCH2CH2), 2.42 (s,
3H, CCH3), 2.14−2.06 (m, 2H, CH2CH), 2.01 (t, J = 2.5 Hz, 1H,
CCH), 1.68 (p, J = 7.5 Hz, 2H, CH2CH2CH2); 13C{1H} NMR
(101 MHz, CDCl3) δ 143.6 (C), 137.6 (CH), 136.1 (C), 129.6
(2xCH), 127.9 (2xCH), 115.5 (CH2), 76.8 (C), 73.8 (CH), 46.0
(CH2), 36.4 (CH2), 30.8 (CH2), 26.9 (CH2), 21.7 (CH3). IR: 2967,
2929, 1735, 1625 cm−1. Anal. Calcd for C15H19NO2S (277.11 g/mol):
C, 64.95; H, 6.90%. Found: C, 65.00; H, 7.04%.
Diethyl 2-((3-(Ethoxycarbonyl)-3-phenylcycloprop-1-en-1-yl)-
methyl)malonate, 2a. It was obtained from diethyl 2-(prop-2-yn-1-
yl)malonate (200 mg, 1.01 mmol) and ethyl 2-diazo-2-phenylacetate
(480.25 mg, 2.23 mmol) following the general procedure for
cyclopropenation reactions and purified by flash column chromatog-
raphy (Hexane/AcOEt, 8:1). Colorless oil (314 mg, 0.87 mmol,
86%); 1H NMR (400 MHz, CDCl3): δ 7.31−7.22 (m, 4H, Ar), 7.22−
7.16 (m, 1H, Ar), 6.79 (t, J = 1.4 Hz, 1H, CCH), 4.22−4.06 (m,
6H, 3xCH2CH3), 3.67 (t, J = 7.5 Hz, 1H, CHCH2), 3.17 (dd, J = 7.5,
1.4 Hz, 2H, CH2C), 1.23 (t, J = 7.1 Hz, 3H, CH2CH3), 1.224 (t, J =
7.1 Hz, 3H, CH2CH3), 1.222 (t, J = 7.1 Hz, 3H, CH2CH3); 13C{1H}
NMR (101 MHz, CDCl3) δ 174.8 (CO), 168.2 (CO), 168.1 (CO),
141.1 (C), 128.2 (2xCH), 128.1 (2xCH), 126.5 (CH), 117.9 (C),
99.9 (CH), 61.9 (2xCH2), 61.0 (CH2), 50.0 (CH), 33.5 (C), 24.2
(CH2), 14.4 (CH3), 14.1 (2xCH3). IR (Neat): 2980, 2921, 2840,
1728 cm−1. Anal. Calcd for C20H24O6 (360.16 g/mol): C, 66.65; H,
6.71%. Found: C, 66.83; H, 6.80%.
Diethyl 2-(3-Methylbut-2-en-1-yl)-2-(prop-2-yn-1-yl)malonate,
1c. It was obtained from diethyl 2-(prop-2-yn-1-yl)malonate (3 g,
15.15 mmol), NaH (436 mg, 18.18 mmol), and 1-bromo-3-
methylbut-2-ene (1.67 mL, 16.67 mmol) following the general
procedure for alkylation reactions. The spectroscopical data (3.31 g,
12.42 mmol, 82%) matched the literature.18 1H NMR (400 MHz,
CDCl3): δ 4.94−4.87 (m, 1H, CHC), 4.26−4.13 (m, 4H,
2xCH2CH3), 2.79−2.75 (m, 4H, CCH2CH + CCH2C), 1.99 (t, J =
Diethyl 2-((3-(Ethoxycarbonyl)cycloprop-1-en-1-yl)methyl)-2-(2-
methylallyl)malonate, 3a. Diethyl 2-(prop-2-yn-1-yl)malonate (381
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mg, 1.92 mmol) was submitted to the general procedure for
cyclopropenation reactions with ethyl diazoacetate (0.76 mL, 4.80
mmol). The crude mixture obtained was then submitted to the
general procedure for alkylation reactions with NaH (55.3 mg, 2.30
mmol) and 3-bromo-2-methylprop-1-ene (0.24 mL, 2.30 mmol). The
titled compound was purified by flash column chromatography
(Hexane/AcOEt, 12:1). Colorless oil (475 mg, 1.40 mmol, 73%, 2
steps); 1H NMR (400 MHz, CDCl3): δ 6.48 (q, J = 1.5 Hz, 1H, C
CH), 4.91−4.87 (m, 1H, CCH2), 4.75−4.72 (m, 1H, CCH2),
4.25−4.13 (m, 4H, 2xCH2CH3), 4.11 (q, J = 7.1 Hz, 2H, CH2CH3),
3.22−3.09 (m, 2H, CH2CCH), 2.78 (q, J = 14.1 Hz, 2H, CH2C
CH2), 2.10 (d, J = 1.5 Hz, 1H, CHCO2), 1.65 (s, 3H, CCH3), 1.30−
1.19 (m, 9H, 3xCH2CH3); 13C NMR (101 MHz, CDCl3) δ 175.8
(CO), 170.6 (CO), 170.5 (CO), 140.1 (C), 116.6 (CH2), 111.8 (C),
97.7 (CH), 61.8 (CH2), 61.8 (CH2), 60.4 (CH2), 55.9 (C), 40.0
(CH2), 28.2 (CH2), 23.4 (CH3), 19.8 (CH), 14.5 (CH3), 14.1
(CH3), 14.1 (CH3). IR (Neat): 2987, 2928, 1730, 1642 cm−1. Anal.
Calcd for C18H26O6 (338.17 g/mol): C, 63.89; H, 7.74%. Found: C,
63.73; H, 7.57%.
Diethyl 2-Allyl-2-((3-(ethoxycarbonyl)cycloprop-1-en-1-yl)-
methyl)malonate, 3b. It was obtained from 1b (2 g, 8.40 mmol)
and ethyl diazoacetate (1.26 mL, 10.08 mmol) following the general
procedure for cyclopropanation reactions and purified by flash
column chromatography (Hexane/AcOEt, 12:1). Product 3b was
isolated with an 18% of diethyl maleate. Colorless oil (2.28 g, 7.06
mmol, 84%). 1H NMR (400 MHz, CDCl3): δ 6.48 (q, J = 1.5 Hz, 1H,
CCH), 5.63 (ddt, J = 17.2, 9.6, 7.5 Hz, 1H, CHCH2), 5.16−5.08
(m, 2H, CHCH2), 4.25 (q, J = 7.2 Hz, 2H, CH2CH3), 4.20 (q, J =
7.1 Hz, 4H, 2xCH2CH3), 3.17−3.05 (m, 2H, CCH2C), 2.81−2.67
(m, 2H, CCH2CH), 2.11 (d, J = 1.5 Hz, 1H, CHCO2), 1.28−1.21
(m, 9H, 3xCH3); 13C{1H} NMR (101 MHz, CDCl3) δ 175.8 (CO),
170.2 (CO), 170.1 (CO), 131.9 (CH), 120.0 (CH2), 111.5 (C), 97.7
(CH), 61.8 (CH2), 61.81 (CH2), 60.5 (CH2), 56.3 (C), 36.9 (CH2),
28.2 (CH2), 19.8 (CH), 14.5 (CH3), 14.2 (CH3), 14.2 (CH3). IR
(Neat): 2983, 2929, 1731, 1643 cm−1. A small sample was purified by
semipreparative HPLC for microanalysis: Anal. Calcd for C17H24O6
(324.16 g/mol): C, 62.95; H, 7.46%. Found: C, 63.01; H, 7.57%.
Diethyl 2-((3-(Ethoxycarbonyl)cycloprop-1-en-1-yl)methyl)-2-(3-
methylbut-2-en-1-yl)malonate, 3c. It was obtained from 1c (3.31 g,
11.8 mmol) and ethyl diazoacetate (1.77 mL, 14.16 mmol) following
the general procedure for cyclopropenation reactions and purified by
flash column chromatography (Hexane/AcOEt, 9:1). Product 3c was
isolated with an 11% of diethyl maleate. Colorless oil (2.93 g, 8.34
mmol, 71%); 1H NMR (400 MHz, CDCl3): δ 6.46 (q, J = 1.5 Hz, 1H,
CCHCH), 4.94 (t, J = 7.6 Hz, 1H, CH2CHC), 4.25 (q, J = 7.1 Hz,
2H, CH2CH3), 4.21−4.14 (m, 4H, CH2CH3), 3.15−3.02 (m, 2H,
CCH2C), 2.77−2.60 (m, 2H, CH2CH), 2.09 (d, J = 1.5 Hz, 1H,
CHCO2), 1.68 (s, 3H, CCH3), 1.58 (s, 3H, CCH3), 1.27−1.20 (m,
9H, 3xCH2CH3); 13C{1H} NMR (101 MHz, CDCl3) δ 175.9 (CO),
170.5 (CO), 170.4 (CO), 136.6 (C), 117.3 (CH), 111.8 (C), 97.6
(CH), 61.7 (CH2), 61.8 (CH2), 60.4 (CH2), 56.6 (C), 31.2 (CH2),
28.2 (CH2), 26.2 (CH3), 19.8 (CH), 18.1 (CH3), 14.5 (CH3), 14.2
(CH3), 14.1 (CH3). IR (Neat): 2979, 2926, 1730, 1642 cm−1. Anal.
Calcd for C19H28O6 (352.19 g/mol): C, 64.75; H, 8.01%. Found: C,
64.87; H, 7.85%.
(CO), 170.9 (CO), 169.9 (CO), 132.2 (CH), 119.5 (CH2), 114.9
(C), 95.1 (CH), 61.5 (2xCH2), 60.4 (CH2), 57.0 (C), 37.4 (CH2),
29.6 (CH2), 20.4 (CH2), 20.0 (CH), 14.5 (CH3), 14.2 (2xCH3). IR
(Neat): 2975, 2934, 1734, 1637 cm−1. Anal. Calcd for C18H26O6
(338.17 g/mol): C, 63.89; H, 7.74%. Found: C, 63.73; H, 7.87%.
Diethyl 2-(But-3-en-1-yl)-2-((3-(ethoxycarbonyl)cycloprop-1-en-
1-yl)methyl)malonate, 3e. Diethyl 2-(prop-2-yn-1-yl)malonate (500
mg, 2.52 mmol) was submitted to the general procedure for
cyclopropenation reactions with ethyl diazoacetate (1.00 mL, 6.30
mmol). The crude mixture obtained was then submitted to the
general procedure for alkylation reactions with NaH (72.6 mg, 3.05
mmol) and 4-bromobut-1-ene (0.32 mL, 3.02 mmol). The titled
compound was purified by flash column chromatography (Hexane/
1
AcOEt, 12:1). Colorless oil (520 mg, 1.54 mmol, 61%, 2 steps); H
NMR (400 MHz, CDCl3): δ 6.48 (q, J = 1.5 Hz, 1H, CCH), 5.77
(ddt, J = 16.6, 10.1, 6.3 Hz, 1H, CHCH2), 5.03 (dq, J = 17.1, 1.5
Hz, 1H, CHCH2 (trans)), 4.97 (dq, J = 10.2, 1.3 Hz, 1H, CH
CH2 (cis)), 4.31−4.03 (m, 6H, 3xCH2CH3), 3.2−3.09 (m, 2H,
CH2CCH), 2.24−1.80 (m, 4H, 2xCH2CH2), 2.11 (d, J = 1.5 Hz,
1H, CHCO2), 1.30−1.21 (m, 9H, 3xCH2CH3); 13C{1H} NMR (101
MHz, CDCl3) δ 175.7 (CO), 170.6 (CO), 170.5 (CO), 137.4 (CH),
115.4 (CH2), 111.5 (C), 97.7 (CH), 61.8 (CH2), 61.7 (CH2), 60.4
(CH2), 56.3 (C), 31.7 (CH2), 28.5 (CH2), 28.5 (CH2), 19.8 (CH),
14.5 (CH3), 14.2 (CH3), 14.1 (CH3). IR (Neat): 2980, 2923, 1732,
1630 cm−1. Anal. Calcd for C18H26O6 (338.17 g/mol): C, 63.89; H,
7.74%. Found: C, 64.08; H, 7.90%.
Diethyl 2-((3-(Ethoxycarbonyl)cycloprop-1-en-1-yl)methyl)-2-
(pent-4-en-1-yl)malonate, 3f. Diethyl 2-(prop-2-yn-1-yl)malonate
(425 mg, 2.14 mmol) was submitted to the general procedure for
cyclopropenation reactions with ethyl diazoacetate (0.85 mL, 5.35
mmol). The crude mixture obtained was then submitted to the
general procedure for alkylation reactions with NaH (61.7 mg, 2.57
mmol) and 5-bromopent-1-ene (0.27 mL, 2.57 mmol). The titled
compound was purified by flash column chromatography (Hexane/
1
AcOEt, 12:1). Colorless oil (361 mg, 1.03 mmol, 48%, 2 steps); H
NMR (400 MHz, CDCl3): δ 6.46 (q, J = 1.5 Hz, 1H, CCH), 5.76
(ddt, J = 16.9, 10.1, 6.6 Hz, 1H, CHCH2), 5.00 (dq, J = 17.3, 1.8
Hz, 1H, CHCH2 (trans)), 4.96 (ddd, J = 10.2, 3.2, 1.3 Hz, 1H,
CHCH2 (cis)), 4.27−4.04 (m, 6H, 3xCH2CH3), 3.24−3.06 (m,
2H, CH2CCH), 2.10 (d, J = 1.5 Hz, 1H, CHCO2), 2.09−1.84 (m,
4H, CH2CH2CH2), 1.35−1.16 (m, 2H of CH2CH2CH2 + 9H of
3xCH2CH3); 13C{1H} NMR (101 MHz, CDCl3) δ 175.8 (CO),
170.7 (CO), 170.6 (CO), 138.1 (CH), 115.2 (CH2), 111.5 (C), 97.6
(CH), 61.7 (CH2), 61.7 (CH2), 60.4 (CH2), 56.5 (C), 33.8 (CH2),
31.9 (CH2), 28.4 (CH2), 23.5 (CH2), 19.8 (CH), 14.5 (CH3), 14.2
(CH3), 14.1 (CH3). IR (Neat): 2990, 2932, 1731, 1642 cm−1. Anal.
Calcd for C19H28O6 (352.19 g/mol): C, 64.75; H, 8.01%. Found: C,
64.59; H, 7.88%.
Ethyl 2-(((N-Allyl-4-methylphenyl)sulfonamido)methyl)cyclo-
prop-2-ene-1-carboxylate, 3g. It was obtained from 1g (300 mg,
1.20 mmol) and ethyl diazoacetate (181 μL, 1.44 mmol) following the
general procedure for cyclopropanation reactions and purified by flash
column chromatography (Hexane/AcOEt, 8:1). Pale yellow oil (258
1
mg, 0.77 mmol, 64%); H NMR (400 MHz, CDCl3): δ 7.71 (d, J =
8.3 Hz, 2H, Ar), 7.29 (d, J = 8.2 Hz, 2H, Ar), 6.18 (q, J = 1.5 Hz, 1H,
CCH), 5.71 (ddt, J = 17.3, 10.0, 6.4 Hz, 1H, CHCH2), 5.24−
5.18 (m, 2H, CHCH2), 4.39 (d, J = 1.6 Hz, 2H, CH2C), 4.14−4.03
(m, 2H, CH2CH3), 3.87 (d, J = 6.5 Hz, 2H, CH2CH), 2.43 (s, 3H,
CCH3), 2.01 (d, J = 1.4 Hz, 1H, CHCO2), 1.23 (t, J = 7.1 Hz, 3H,
CH2CH3); 13C{1H} NMR (101 MHz, CDCl3) δ 175.2 (CO), 143.7
(C), 137.0 (C), 132.2 (CH), 129.8 (2xCH), 127.6 (2xCH), 120.1
(CH2), 110.7 (C), 98.8 (CH), 60.6 (CH2), 49.9 (CH2), 42.0 (CH2),
21.7 (CH3), 20.5 (CH), 14.5 (CH3). IR (Neat): 2985, 2923, 2849,
1725, 1640 cm−1. Anal. Calcd for C17H21NO4S (335.12 g/mol): C,
60.88; H, 6.31%. Found: C, 60.72; H, 6.12%.
Ethyl 2-(((4-Methyl-N-(2-methylallyl)phenyl)sulfonamido)-
methyl)cycloprop-2-ene-1-carboxylate, 3h. It was obtained from
1h (724 mg, 2.75 mmol) and ethyl diazoacetate (0.42 mL, 3.34
mmol) following the general procedure for cyclopropanation
reactions and purified by flash column chromatography (Hexane/
Diethyl 2-Allyl-2-(2-(3-(ethoxycarbonyl)cycloprop-1-en-1-yl)-
ethyl)malonate, 3d. Diethyl 2-(but-3-yn-1-yl)malonate (700 mg,
3.30 mmol) was submitted to the general procedure for cyclo-
propenation reactions with ethyl diazoacetate (1.30 mL, 8.25 mmol).
The crude mixture obtained was then submitted to the general
procedure for alkylation reactions with NaH (95 mg, 3.96 mmol) and
allyl bromide (0.34 mL, 3.96 mmol). The titled compound was
purified by flash column chromatography (Hexane/AcOEt, 8:1).
1
Colorless oil (748 mg, 2.21 mmol, 67%, 2 steps); H NMR (400
MHz, CDCl3): δ 6.38 (q, J = 1.5 Hz, 1H, CCH), 5.64 (ddt, J =
17.5, 10.2, 7.4 Hz, 1H, CHCH2), 5.17−5.08 (m, 2H, CHCH2),
4.24−4.07 (m, 6H, 3xCH2CH3), 2.67 (d, J = 7.4 Hz, 2H, CH2CH),
2.50−2.41 (m, 2H, CH2CCH), 2.17 (d, J = 8.2 Hz, 2H,
CH2CH2CCH), 2.14 (d, J = 1.5 Hz, 1H, CHCO2), 1.25 (t, J =
7.0 Hz, 9H, 3xCH2CH3); 13C{1H}NMR (101 MHz, CDCl3) δ 176.3
928
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The Journal of Organic Chemistry
Article
1
AcOEt, 9:1). Pale yellow oil (679 mg, 1.95 mmol, 71%); H NMR
(400 MHz, CDCl3): δ 7.71 (d, J = 8.2 Hz, 2H, Ar), 7.29 (d, J = 8.3
Hz, 2H, Ar), 6.05 (q, J = 1.6 Hz, 1H, CCH), 4.94 (s, 1H, C
CH2), 4.89 (s, 1H, CCH2), 4.42−4.28 (m, 2H, CH2CCH),
4.11−4.03 (m, J = 7.1, 3.6 Hz, 2H, CH2CH3), 3.79 (s, 2H, CH2C
CH2), 2.43 (s, 3H, Ar-CH3), 1.93 (d, J = 1.4 Hz, 1H, CHCO2), 1.74
(s, 3H, CH2CCH3), 1.23 (t, J = 7.2 Hz, 3H, CH2CH3); 13C{1H}
NMR (101 MHz, CDCl3) δ 175.2 (CO), 143.6 (C), 139.5 (C), 137.1
(C), 129.7 (2xCH), 127.7 (2xCH), 115.7 (CH2), 110.4 (C), 98.6
(CH), 60.6 (CH2), 53.3 (CH2), 41.6 (CH2), 21.7 (CH3), 20.4 (CH),
19.8 (CH3), 14.5 (CH3). IR (Neat): 2988, 2925, 2848, 1723, 1646
cm−1. Anal. Calcd for C18H23NO4S (349.13 g/mol): C, 61.87; H,
6.63%. Found: C, 62.04; H, 6.82%.
Diethyl 2-((3-(Ethoxycarbonyl)-3-phenylcycloprop-1-en-1-yl)-
methyl)-2-(2-methylallyl)malonate, 3l. It was obtained from 2a
(250 mg, 0.70 mmol) and 3-bromo-2-methylprop-1-ene (84 μL, 0.84
mmol) following the general procedure for alkylation reactions with
NaH (34 mg, 0.84 mmol) and purified by flash column
chromatography (Hexane/AcOEt, 19:1). Colorless oil (256 mg,
1
0.62 mmol, 89%); H NMR (400 MHz, CDCl3): δ 7.29−7.15 (m,
5H, Ar), 6.79 (t, J = 1.7 Hz, 1H, CCH), 4.84−4.81 (m, 1H, C
CH2), 4.67−4.62 (m, 1H, CCH2), 4.24−3.98 (m, 6H, 3xCH2CH3),
3.28−3.09 (m, 2H, CH2CCH), 2.88−2.78 (m, 2H, CH2CCH2),
1.61 (s, 3H, CCH3), 1.24 (t, J = 7.2 Hz, 3H, CH2CH3), 1.21 (t, J =
7.2 Hz, 3H, CH2CH3), 1.09 (t, J = 7.1 Hz, 3H, CH2CH3); 13C{1H}
NMR (101 MHz, CDCl3) δ 174.8 (CO), 170.5 (CO), 170.4 (CO),
141.1 (C), 139.9 (C), 128.3 (2xCH), 128.1 (2xCH), 126.5 (CH),
117.3 (C), 116.6 (CH2), 100.2 (CH), 61.9 (CH2), 61.8 (CH2), 60.9
(CH2), 55.9 (C), 39.8 (CH2), 32.5 (C), 27.6 (CH2), 23.4 (CH3),
14.4 (CH3), 14.1 (CH3), 14.0 (CH3). IR (Neat): 2985, 2914, 2846,
1728 cm−1. Anal. Calcd for C24H30O6 (414.20 g/mol): C, 69.55; H,
7.30%. Found: C, 69.67; H, 7.49%.
Ethyl 2-(((N-(But-3-en-1-yl)-4-methylphenyl)sulfonamido)-
methyl)cycloprop-2-ene-1-carboxylate, 3i. It was obtained from 1i
(200 mg, 0.68 mmol) and ethyl diazoacetate (0.10 mL, 0.82 mmol)
following the general procedure for cyclopropanation reactions and
purified by flash column chromatography (Hexane/AcOEt, 8:1). Pale
yellow oil (157 mg, 0.45 mmol, 66%); 1H NMR (400 MHz, CDCl3):
δ 7.70 (d, J = 8.3 Hz, 2H, Ar), 7.28 (d, J = 8.0 Hz, 2H, Ar), 6.18 (q, J
= 1.6 Hz, 1H, CCH), 5.73 (ddt, J = 17.0, 10.2, 6.8 Hz, 1H, CH
CH2), 5.12−5.02 (m, 2H, CHCH2), 4.51−4.35 (m, 2H, NCH2C),
4.14−4.04 (m, 2H, CH2CH3), 3.30 (td, J = 7.1, 1.8 Hz, 2H,
NCH2CH2), 2.43 (s, 3H, CCH3), 2.37−2.29 (m, 2H, CH2CH
CH2), 2.03 (d, J = 1.5 Hz, 1H, CHCO2), 1.24 (t, J = 7.1 Hz, 3H,
CH2CH3); 13C{1H} NMR (101 MHz, CDCl3) δ 175.2 (CO), 143.7
(C), 136.9 (C), 134.6 (CH), 129.8 (2xCH), 127.6 (2xCH), 117.5
(CH2), 110.8 (C), 98.7 (CH), 60.6 (CH2), 46.8 (CH2), 43.0 (CH2),
32.7 (CH2), 21.7 (CH3), 20.5 (CH), 14.5 (CH3). IR (Neat): 2990,
2920, 2858, 1727, 1642 cm−1. Anal. Calcd for C18H23NO4S (349.13
g/mol): C, 61.87; H, 6.63%. Found: C, 61.70; H, 6.80%.
Ethyl 2-(((4-Methyl-N-(pent-4-en-1-yl)phenyl)sulfonamido)-
methyl)cycloprop-2-ene-1-carboxylate, 3j. It was obtained from 1j
(1.38 g, 4.98 mmol) and ethyl diazoacetate (787 μL, 6.29 mmol)
following the general procedure for cyclopropanation reactions and
purified by flash column chromatography (Hexane/AcOEt, 9:1). Pale
yellow oil (945 mg, 2.60 mmol, 52%). 1H NMR (400 MHz, CDCl3):
δ 7.70 (d, J = 8.3 Hz, 2H, Ar), 7.28 (d, J = 8.0 Hz, 2H, Ar), 6.16 (q, J
= 1.5 Hz, 1H, CHC), 5.77 (ddt, J = 16.9, 10.2, 6.6 Hz, 1H, CH
CH2), 5.06−4.95 (m, 2H, CHCH2), 4.48−4.33 (m, 2H, NCH2C),
4.14−4.03 (m, 2H, CH2CH3), 3.26−3.19 (m, 2H, NCH2CH2), 2.43
(s, 3H, CCH3), 2.11−2.04 (m, 2H, CH2CH2CH2), 2.02 (d, J = 1.4
Hz, 1H, CHCO2), 1.71−1.61 (m, 2H, CH2CHCH2), 1.23 (t, J =
7.1 Hz, 3H, CH2CH3); 13C{1H} NMR (1 01 MHz, CDCl3) δ 175.2
(CO), 143.6 (C), 137.5 (CH), 136.8 (C), 129.7 (2xCH), 127.6
(2xCH), 115.5 (CH2), 110.8 (C), 98.6 (CH), 60.6 (CH2), 47.0
(CH2), 42.9 (CH2), 30.7 (CH2), 27.2 (CH2), 21.7 (CH3), 20.5
(CH), 14.5 (CH3). IR (Neat): 2988, 2917, 2858, 1729, 1643 cm−1.
Anal. Calcd for C19H25NO4S (363.15 g/mol): C, 62.79; H, 6.93%.
Found: C, 62.90; H, 7.06%.
Diethyl 2-((3-(Ethoxycarbonyl)-3-phenylcycloprop-1-en-1-yl)-
methyl)-2-(3-methylbut-2-en-1-yl)malonate, 3m. It was obtained
from 2a (250 mg, 0.70 mmol) and 1-bromo-3-methylbut-2-ene (97
μL, 0.84 mmol) following the general procedure for alkylation
reactions with NaH (34 mg, 0.84 mmol) and purified by flash column
chromatography (Hexane/AcOEt, 19:1). Colorless oil (246 mg, 0.57
1
mmol, 81%); H NMR (400 MHz, CDCl3): δ 7.31−7.16 (m, 5H,
Ar), 6.77 (t, J = 1.7 Hz, 1H, CH2CCH), 4.90 (tt, J = 7.6, 1.4 Hz,
1H, CH2CHC), 4.21−3.98 (m, 6H, 3xCH2CH3), 3.22−3.05 (m, 2H,
CCH2C), 2.75 (d, J = 7.6 Hz, 2H, CCH2CH), 1.64 (s, 3H, CCH3),
1.49 (s, 3H, CCH3), 1.22 (t, J = 7.1 Hz, 3H, CH2CH3), 1.21 (t, J =
7.1 Hz, 3H, CH2CH3), 1.11 (t, J = 7.1 Hz, 3H, CH2CH3); 13C{1H}
NMR (101 MHz, CDCl3) δ 174.8 (CO), 170.4 (2xCO), 141.2 (C),
136.6 (C), 128.3 (2xCH), 128.1 (2xCH), 126.4 (CH), 117.2 (CH),
117.1 (C), 100.1 (CH), 61.7 (CH2), 61.6 (CH2), 60.9 (CH2), 56.7
(C), 32.5 (C), 30.9 (CH2), 27.7 (CH2), 26.2 (CH3), 18.0 (CH3),
14.4 (CH3), 14.1 (CH3), 14.0 (CH3). IR (Neat): 2988, 2920, 2853,
1729 cm−1. Anal. Calcd for C25H32O6 (428.22 g/mol): C, 70.07; H,
7.53%. Found: C, 70.21; H, 7.37%.
Diethyl 2-((3-(Ethoxycarbonyl)-3-phenylcycloprop-1-en-1-yl)-
methyl)-2-(pent-4-en-1-yl)malonate, 3n. It was obtained from 2a
(320 mg, 0.89 mmol) and 5-bromopent-1-ene (0.13 mL, 1.07 mmol)
following the general procedure for alkylation reactions with NaH (40
mg, 0.98 mmol) and purified by flash column chromatography
(Hexane/AcOEt, 13:1). Colorless oil (154 mg, 0.36 mmol, 41%); 1H
NMR (400 MHz, CDCl3): δ 7.30−7.16 (m, 5H, Ar), 6.74 (t, J = 1.6
Hz, 1H CCH), 5.70 (ddt, J = 16.9, 10.2, 6.6 Hz, 1H, CHCH2),
5.01−4.91 (m, 2H, CHCH2), 4.22−4.01 (m, 6H, 3xCH2CH3),
3.26−3.09 (m, 2H, CCH2C), 2.08−1.92 (m, 4H, CH2CH2CH2),
1.34−1.15 (m, 2H, CH2CH2CH2), 1.23 (t, J = 7.1 Hz, 3H, CH2CH3),
1.22 (t, J = 7.1 Hz, 3H, CH2CH3), 1.12 (t, J = 7.1 Hz, 3H, CH2CH3);
13C{1H} NMR (101 MHz, CDCl3) δ 174.7 (CO), 170.6 (CO), 170.5
Diethyl 2-Allyl-2-((3-(ethoxycarbonyl)-3-phenylcycloprop-1-en-
1-yl)methyl)malonate, 3k. It was obtained from 2a (240 mg, 0.85
mmol) and allyl bromide (0.89 mL, 1.02 mmol) following the general
procedure for alkylation reactions with NaH (24.5 mg, 1.02 mmol)
and purified by flash column chromatography (Hexane/AcOEt, 13:1).
Colorless oil (228 mg, 0.57 mmol, 67%); 1H NMR (400 MHz,
CDCl3): δ 7.30−7.16 (m, 5H, Ar), 6.78 (t, J = 1.6 Hz, 1H, CCH),
5.59 (ddt, J = 17.6, 10.2, 7.5 Hz, 1H, CHCH2), 5.06 (ddt, J = 10.2,
1.9, 0.9 Hz, 1H, CHCH2 (cis)), 5.02 (dq, J = 16.9, 1.4 Hz, 1H,
CHCH2 (trans)), 4.28−3.99 (m, 6H,3x CH2CH3), 3.24−3.04 (m,
2H, CCH2C), 2.90−2.68 (m, 2H, CH2CH), 1.23 (t, J = 7.1 Hz, 3H,
CH2CH3), 1.22 (t, J = 7.1 Hz, 3H, CH2CH3), 1.13 (t, J = 7.1 Hz, 3H,
CH2CH3); 13C{1H} NMR (101 MHz, CDCl3) δ 174.8 (CO), 170.1
(2xCO), 141.2 (C), 131.8 (CH), 128.3 (2xCH), 128.1 (2xCH),
126.5 (CH), 120.1 (CH2), 116.9 (C), 100.3 (CH), 61.9 (CH2), 61.8
(CH2), 60.9 (CH2), 56.3 (C), 36.7 (CH2), 32.5 (C), 27.7 (CH2),
14.4 (CH3), 14.2 (CH3), 14.1 (CH3). IR (Neat): 2990, 2923, 2845,
1730 cm−1. Anal. Calcd for C23H28O6 (400.19 g/mol): C, 68.98; H,
7.05%. Found: C, 68.84; H, 7.21%.
(CO), 141.2 (C), 138.1 (CH), 128.2 (2xCH), 128.1 (2xCH), 126.5
(CH), 117.0 (C), 115.2 (CH2), 99.9 (CH), 61.7 (CH2), 61.6 (CH2),
60.9 (CH2), 56.5 (C), 33.8 (CH2), 32.6 (C), 31.7 (CH2), 27.8
(CH2), 23.4 (CH2), 14.5 (CH3), 14.1 (CH3), 14.0 (CH3). IR (Neat):
2988, 2923, 2848, 1729 cm−1. Anal. Calcd for C25H32O6 (428.22 g/
mol): C, 70.07; H, 7.53%. Found: C, 70.19; H, 7.60%.
General Procedure for Cycloisomerization Reactions with
Gold Catalysts. To a stirred solution, in a microwave vessel, of the
cyclopropenated compound (1 equiv) in toluene anh. (0.25/mmol)
was added AuCl or AuCl3 (0.1 equiv). Then, the vessel was sealed,
and the mixture was heated up to 100 °C using microwave irradiation
and stirred for 60 min. After this, the mixture was cooled down,
concentrated under vacuum and purified by flash column chromatog-
raphy.
Diethyl (E)-5-(2-Ethoxy-2-oxoethylidene)-1-methylbicyclo[4.1.0]-
heptane-3,3-dicarboxylate, 4a. It was obtained from 3a (50 mg,
0.15 mmol) following the general procedure for cycloisomerization
reactions with gold catalysts and purified by flash column
chromatography (Hexane/AcOEt, 12:1). NOESY spectra showed
929
DOI: 10.1021/acs.joc.8b02849
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The Journal of Organic Chemistry
Article
strong cross-peak between olefinic proton and H6. Colorless oil (38
mg, 0.11 mmol, 75%); H NMR (400 MHz, CDCl3): δ 5.86 (d, J =
COCCHHCCH), 2.48 (dd, J = 13.8, 5.1 Hz, 1H, COCCHHCCH),
1.64 (m, 1H, CH cyclopropane), 1.26 (t, J = 7.2 Hz, 3H, CH2CH3),
1.24 (t, J = 7.1 Hz, 3H, CH2CH3), 1.21 (t, J = 7.1 Hz, 3H, CH2CH3),
0.92 (t, J = 7.8 Hz, 1H, CH2 cyclopropane), 0.79 (t, J = 5.6, 1H, CH2
cyclopropane); 13C{1H} NMR (101 MHz, CDCl3) δ 172.5 (CO),
171.4 (CO), 166.9 (CO), 153.1 (CH), 117.4 (CH), 62.1 (CH2), 62.0
(CH2), 60.3 (CH2), 59.5 (C), 36.4 (CH2), 35.4 (CH2), 31.7 (C),
28.6 (CH), 19.6 (CH2), 14.4 (CH3), 14.1 (CH3), 14.0 (CH3).
Diethyl (E)-6-(3-Ethoxy-3-oxoprop-1-en-1-yl)bicyclo[4.1.0]-
heptane-3,3-dicarboxylate, 5d. It was obtained from 3d (70 mg,
0.21 mmol) following the general procedure for cycloisomerization
reactions with Cp*RuCl(cod) and purified by flash column
chromatography (Hexane/AcOEt, 12:1). Colorless oil (57 mg, 0.17
1
1.9 Hz, 1H, CCH), 4.30 (dd, J = 15.4, 2.2 Hz, 1H, CH2CCH),
4.20−4.09 (m, 6H, 3xCH2CH3), 2.51 (dd, J = 14.2, 2.2 Hz, 1H,
CH2CCH3), 2.17 (dd, J = 15.3, 2.1 Hz, 1H, CH2CCH), 1.90 (d, J =
14.1 Hz, 1H, CH2CCH3), 1.43 (dd, J = 9.3, 5.0 Hz, 1H, CCHC),
1.25 (t, J = 7.1 Hz, 3H, CH2CH3), 1.24 (s, 3H, CCH3), 1.22 (t, J =
7.1 Hz, 3H, CH2CH3), 1.17 (t, J = 7.1 Hz, 3H, CH2CH3), 0.88 (dd, J
= 9.3, 4.6 Hz, 1H, CH2CH), 0.72 (t, J = 4.8 Hz, 1H, CH2CH);
13C{1H} NMR (101 MHz, CDCl3) δ 171.4 (CO), 170.7 (CO), 165.8
(CO), 157.5 (C), 115.5 (CH), 61.7 (CH2), 61.4 (CH2), 59.6 (CH2),
56.1 (C), 36.4 (CH2), 29.7 (CH), 28.6 (CH2), 27.0 (CH3), 25.6
(CH2), 21.6 (C), 14.5 (CH3), 14.1 (CH3), 14.0 (CH3). IR (Neat):
2982, 2933, 2907, 1734, 1711, 1633 cm−1. Anal. Calcd for C18H26O6
(338.17 g/mol): C, 63.89; H, 7.74%. Found: C, 64.06; H, 7.61%.
Ethyl (Z)-2-(3-Tosyl-3-azabicyclo[4.1.0]heptan-5-ylidene)-
acetate, 4b. It was obtained from 3g (50 mg, 0.15 mmol) following
the general procedure for cycloisomerization reactions with gold
catalysts and purified by flash column chromatography (Hexane/
AcOEt, 6:1). NOESY spectra showed strong cross-peak between
olefinic proton and H6. Colorless oil (30 mg, 0.09 mmol, 60% yield);
1H NMR (400 MHz, CDCl3): δ 7.67 (d, J = 8.2 Hz, 2H, Ar), 7.32 (d,
J = 8.0 Hz, 2H, Ar), 5.77 (t, J = 2.4 Hz, 1H, CCH), 5.00 (d, J =
18.4 Hz, 1H, NCH2C), 4.16−4.08 (m, 2H, CH2CH3), 4.05−3.96
(m, 1H, NCH2CH), 3.36 (dd, J = 18.4, 2.6 Hz, 1H, NCH2CCH),
2.67 (dd, J = 11.6, 2.2 Hz, 1H, NCH2CH), 2.42 (s, 3H, CCH3),
1.75−1.65 (m, 1H, CHCH2CH), 1.60−1.50 (m, 1H, CH2CHCH2),
1.33 (q, J = 4.9 Hz, 1H, CCHCH2), 1.27 (t, J = 7.8 Hz, 3H,
CH2CH3), 0.99 (ddd, J = 9.4, 7.7, 4.8 Hz, 1H, CHCH2CH); 13C{1H}
NMR (101 MHz, CDCl3) δ 165.6 (CO), 154.7 (C), 143.8 (C), 133.3
(C), 130.0 (2xCH), 127.7 (2xCH), 115.2 (CH), 59.9 (CH2), 47.3
(CH2), 43.2 (CH2), 21.7 (CH3), 18.5 (CH2), 14.5 (CH3), 14.3
(CH), 10.5 (CH). IR (Neat): 2986, 2925, 2863, 1730, 1642 cm−1.
Anal. Calcd for C17H21NO4S (335.12 g/mol): C, 60.88; H, 6.31%.
Found: C, 60.71; H, 6.40%.
General Procedure for Cycloisomerization Reactions with
Cp*RuCl(cod). To a solution, of the cyclopropenated compound (1
equiv) in toluene anh. (0.25 mL/mmol) placed into a microwave
vessel was added Cp*RuCl(cod) (10 mol %). Then, the vessel was
sealed and the mixture was heated up to 100 °C (50 °C for
compound 7a) using microwave irradiation and stirred for 5 min.
After this, the mixture was cooled down, concentrated under vacuum,
and purified by flash column chromatography.
1
mmol, 81%); H NMR (400 MHz, CDCl3): δ 6.49 (d, J = 15.7 Hz,
1H, CHCHCO2), 5.67 (d, J = 15.7 Hz, 1H, CHCHCO2), 4.26−
4.07 (m, 6H, 3xCH2CH3), 2.81 (ddd, J = 14.2, 8.9, 2.2 Hz, 1H,
CCH2CH), 2.22−2.13 (m, 1H, CH2CH2), 1.96−1.88 (m, 1H,
CH2CH2), 1.81 (td, J = 13.6, 5.0 Hz, 1H, CH2CH2), 1.68−1.57
(m, 2H, CH2CH2 + CCH2CH), 1.38−1.28 (m, 1H, CH2CH), 1.27 (t,
J = 7.1 Hz, 3H, CH2CH3), 1.24 (t, J = 7.2 Hz, 3H, CH2CH3), 1.22 (t,
J = 7.2 Hz, 3H, CH2CH3), 0.99 (dd, J = 9.2, 5.0 Hz, 1H, CH2
cyclopropane), 0.71 (t, J = 5.6 Hz, 1H, CH2 cyclopropane); 13C{1H}
NMR (101 MHz, CDCl3) δ 172.3 (CO), 170.8 (CO), 167.1 (CO),
157.4 (CH), 116.4 (CH), 61.6 (CH2), 61.5 (CH2), 60.3 (CH2), 52.6
(C), 30.0 (CH2), 25.5 (CH2), 21.7 (CH2), 21.6 (C), 21.1 (CH2),
20.1 (CH), 14.5 (CH3), 14.3 (CH3), 14.2 (CH3). IR (Neat): 2982,
2923, 2872, 1730, 1643 cm−1. Anal. Calcd for C18H26O6 (338.17 g/
mol): C, 63.89; H, 7.74%. Found: C, 63.79; H, 7.59%.
Diethyl (E)-1-(3-Ethoxy-3-oxoprop-1-en-1-yl)bicyclo[4.1.0]-
heptane-3,3-dicarboxylate, 5e. It was obtained from 3e following
the general procedure for cycloisomerization reactions with Cp*RuCl-
(cod) and purified by flash column chromatography (Hexane/AcOEt,
1
12:1). Colorless oil (30 mg, 0.10 mmol, 60%); H NMR (400 MHz,
CDCl3): δ 6.61 (d, J = 15.7 Hz, 1H, CHCHCO2), 5.87 (d, J = 15.6
Hz, 1H, CHCHCO2), 4.21−4.13 (m, 6H, 3xCH2CH3), 2.93 (dd, J
= 14.7, 1.6 Hz, 1H, CCH2C), 2.11−2.06 (m, 1H, CH2CH2), 2.02−
1.69 (m, 2H, CH2CH2), 1.73 (d, J = 14.6 Hz, 1H, CCH2C), 1.60 (dd,
J = 13.5, 5.3 Hz, 1H, CH2CH2), 1.31−1.20 (m, 10H, CH2CH +
3xCH2CH3), 1.05 (dd, J = 9.4, 4.9 Hz, 1H, CH2 cyclopropane), 0.72
(dd, J = 6.3, 4.6 Hz, 1H, CH2 cyclopropane); 13C{1H} NMR (101
MHz, CDCl3) δ 172.2 (CO), 170.9 (CO), 167.3 (CO), 157.5 (CH),
116.2 (CH), 61.6 (CH2), 61.5 (CH2), 60.2 (CH2), 52.7 (C), 32.3
(CH2), 24.9 (CH2), 23.1 (CH), 22.4 (CH2), 20.4 (C), 19.5 (CH2),
14.5 (CH3), 14.2 (CH3), 14.2 (CH3). IR (Neat): 2980, 2924, 2875,
1730, 1641 cm−1. Anal. Calcd for C18H26O6 (338.17 g/mol): C,
63.89; H, 7.74%. Found: C, 64.05; H, 7.57%.
Diethyl (E)-1-(3-Ethoxy-3-oxoprop-1-en-1-yl)-5-methylbicyclo-
[3.1.0]hexane-3,3-dicarboxylate, 5a. It was obtained from 3a (60
mg, 0.18 mmol) following the general procedure for cycloisomeriza-
tion reactions with Cp*RuCl(cod) and purified by flash column
chromatography (Hexane/AcOEt, 12:1). Colorless oil (478 mg, 0.13
Diethyl (E)-1-(3-Ethoxy-3-oxoprop-1-en-1-yl)bicyclo[5.1.0]-
octane-3,3-dicarboxylate, 5f. It was obtained from 3f (80 mg, 0.23
mmol) following the general procedure for cycloisomerization
reactions with Cp*RuCl(cod) and purified by flash column
chromatography (Hexane/AcOEt, 12:1). Colorless oil (42 mg, 0.12
1
mmol, 78%); H NMR (400 MHz, CDCl3): δ 6.75 (d, J = 15.7 Hz,
1H, CHCHCO2), 5.83 (d, J = 15.6 Hz, 1H, CHCHCO2), 4.23−
4.12 (m, 6H, 3xCH2CH3), 2.76−2.59 (m, 3H, COCCH2CCH +
COCCHHCCH3), 2.32 (dd, J = 13.8, 1.5 Hz, 1H, COCCHHCCH3),
1.28 (t, J = 7.1 Hz, 3H, CH2CH3), 1.25 (t, J = 7.1 Hz, 3H, CH2CH3),
1.24 (s, 3H, CH3), 1.23 (t, J = 7.1 Hz, 3H, CH2CH3), 0.89 (d, J = 6.0
Hz, 1H, CH2 cyclopropane), 0.76 (dt, J = 6.0, 1.5 Hz, 1H, CH2
cyclopropane); 13C{1H} NMR (101 MHz, CDCl3) δ 172.5 (CO),
171.6 (CO), 166.8 (CO), 151.3 (CH), 118.7 (CH), 62.1 (CH2), 61.9
(CH2), 60.3 (CH2), 57.8 (C), 42.2 (CH2), 37.9 (CH2), 34.9 (C),
34.7 (C), 25.2 (CH2), 18.7 (CH3), 14.5 (CH3), 14.2 (CH3), 14.1
(CH3). IR (Neat): 2985, 2930, 1734, 1640 cm−1. Anal. Calcd for
C18H26O6 (338.17 g/mol): C, 63.89; H, 7.74%. Found: C, 64.08; H,
7.90%.
Diethyl (E)-1-(3-Ethoxy-3-oxoprop-1-en-1-yl)bicyclo[3.1.0]-
hexane-3,3-dicarboxylate, 5b. It was obtained from 3b (50 mg,
0.15 mmol) following the general procedure for cycloisomerization
reactions with Cp*RuCl(cod). The spectroscopical data of the
product (47 mg, 0.14 mmol, 94%) matched those described in the
literature.9c 1H NMR (400 MHz, CDCl3): δ 6.66 (d, J = 15.6 Hz, 1H,
CHCHCO2), 5.80 (d, J = 15.6 Hz, 1H, CHCHCO2), 4.20−4.11
(m, 6H, 3xCH2CH3), 2.65−2.57 (m, 3H, COCCH2CCH +
1
mmol, 52%); H NMR (400 MHz, CDCl3): δ 6.80 (d, J = 15.8 Hz,
1H, CHCHCO2), 5.50 (d, J = 15.8 Hz, 1H, CHCHCO2), 4.30−
4.01 (m, 6H, 3xCH2CH3), 2.90 (d, J = 15.9 Hz, 1H, CCH2C), 2.30
(ddd, J = 13.5, 9.0, 3.9 Hz, 1H, CCH2CH2), 2.25−2.17 (m, 1H,
CH2CH2CH), 2.11 (d, J = 15.9 Hz, 1H, CCH2C), 2.01−1.86 (m, 1H,
CH2CH2CH2), 1.76−1.66 (m, 1H, CCH2CH2), 1.64−1.54 (m, 1H,
CH2CH2CH2), 1.37−1.28 (m, 1H, CH2CHCH2), 1.30−1.23 (m, 6H,
2xCH2CH3), 1.23 (t, J = 7.1 Hz, 3H, CH2CH3), 1.12−1.03 (m, 1H,
CH2CH2CH), 0.98−0.92 (m, 1H, CH2 cyclopropane), 0.75 (dd, J =
5.8, 4.4 Hz, 1H, CH2 cyclopropane); 13C{1H} NMR (101 MHz,
CDCl3) δ 172.3 (CO), 172.0 (CO), 167.1 (CO), 156.2 (CH), 116.0
(CH), 61.6 (CH2), 61.4, (CH2), 60.2, (CH2), 56.8 (C), 36.6 (CH2),
33.4 (CH2), 28.9 (CH2), 28.7 (CH2), 26.2 (CH), 23.9 (CH2), 23.4
(C), 14.4 (CH3), 14.2 (CH3), 14.0 (CH3). IR (Neat): 2982, 2924,
2853, 1731 cm−1. Anal. Calcd for C19H28O6 (352.19 g/mol): C,
64.75; H, 8.01%. Found: C, 64.94; H, 7.87%.
Ethyl (E)-3-(3-Tosyl-3-azabicyclo[3.1.0]hexan-1-yl)acrylate, 5g. It
was obtained from 3g (50 mg, 0.15 mmol) following the general
procedure for cycloisomerization reactions with Cp*RuCl(cod) and
930
DOI: 10.1021/acs.joc.8b02849
J. Org. Chem. 2019, 84, 924−933

The Journal of Organic Chemistry
Article
purified by flash column chromatography (Hexane/AcOEt, 4:1). The
spectroscopical data of the product (47 mg, 0.14 mmol, 94%)
matched those described in the literature;9c,e 1H NMR (400 MHz,
CDCl3): δ 7.68 (d, J = 8.2 Hz, 2H, Ar), 7.34 (d, J = 8.0 Hz, 2H, Ar),
6.62 (d, J = 15.8 Hz, 1H, CHCHCO2), 5.68 (d, J = 15.8 Hz, 1H,
CHCHCO2), 4.15 (q, J = 7.1 Hz, 2H, CH2CH3), 3.60 (d, J = 9.0 Hz,
1H, NCH2C), 3.59 (d, J = 9.3 Hz, 1H, NCH2CH), 3.11 (d, J = 9.0
Hz, 1H, NCH2C), 3.07 (dd, J = 9.3, 3.8 Hz, 1H, NCH2CH), 2.44 (s,
3H, CCH3), 1.70−1.67 (m, 1H, CH2CH), 1.26 (t, J = 7.1 Hz, 3H,
CH2CH3), 1.21 (t, J = 5.2 Hz, 1H, CH2 cyclopropane), 1.06 (dd, J =
8.1, 5.3 Hz, 1H, CH2 cyclopropane). 13C{1H}(101 MHz, CDCl3) δ
166.3 (CO), 148.9 (CH), 144.0 (C), 132.9 (C), 129.9 (CH), 127.7
(CH), 118.5 (CH), 60.5 (CH2), 50.1 (CH2), 49.4 (CH2), 29.9 (C),
26.6 (CH), 21.7 (CH3), 17.2 (CH2), 14.3 (CH3). IR (Neat): 2982,
2924, 2853, 1731 cm−1. Anal. Calcd for C17H21NO4S (335.12 g/mol):
C, 60.88; H, 6.31%. Found: C, 60.99; H, 6.45%.
Ethyl (E)-3-(5-Methyl-3-tosyl-3-azabicyclo[3.1.0]hexan-1-yl)-
acrylate, 5h. It was obtained from 3h (70 mg, 0.20 mmol) following
the general procedure for cycloisomerization reactions with Cp*RuCl-
(cod) and purified by flash column chromatography (Hexane/AcOEt,
8:1). The spectroscopical data of the product (46 mg, 0.13 mmol,
66%) matched those described in the literature;9c,e 1H NMR (400
MHz, CDCl3): δ 7.68 (d, J = 8.3 Hz, 2H, Ar), 7.34 (d, J = 8.0 Hz, 2H,
Ar), 6.66 (d, J = 15.8 Hz, 1H, CHCHCO2), 5.68 (d, J = 15.8 Hz, 1H,
CHCHCO2), 4.16 (q, J = 7.0 Hz, 2H, CH2CH3), 3.60 (d, J = 9.1 Hz,
2H, NCH2CCH3 + NCH2CCH), 3.10 (d, J = 9.0 Hz, 1H,
NCH2CCH), 2.81 (d, J = 9.1 Hz, 1H, NCH2CCH3), 2.44 (s, 3H,
Ar-CH3), 1.31−1.23 (m, 4H, CH2CH3 + CH2 cyclopropane), 1.16 (s,
3H, CH2CCH3), 0.89 (d, J = 5.2 Hz, 1H, CH2 cyclopropane).
3C{1H}(101 MHz, CDCl3) δ 166.2 (CO), 146.9 (CH), 143.9 (C),
135.2 (C), 129.9 (2xCH), 127.5 (2xCH), 117.2 (CH), 60.3 (CH2),
52.8 (CH2), 51.9 (CH2), 29.2 (CH2), 28.6 (CH2), 28.2 (CH), 26.8
(C), 24.3 (CH2), 21.7 (CH3), 14.5 (CH3). IR (Neat): 2987, 2920,
2862, 1727, 1643 cm−1. Anal. Calcd for C19H25NO4S (363.15 g/mol):
C, 62.79; H, 6.93%. Found: C, 62.92; H, 7.09%.
Diethyl (3aR*,6S*,7aR*)-6-Ethoxy-5-phenyl-1,6,7,7a-tetrahydro-
3a,6-epoxyindene-2,2(3H)-dicarboxylate, 6a. It was obtained from
3k (50 mg, 0.13 mmol) following the general procedure for
cycloisomerization reactions with Cp*RuCl(cod) and purified by
flash column chromatography (Hexane/AcOEt, 13:1). NOESY
spectra showed cross-peak between the CH2CHCH2 and the olefinic
proton. Thus, the titled compound was assigned as (3aR*,6S*,7aR*).
1
Colorless oil (34 mg, 0.08, 64%); H NMR (400 MHz, CDCl3): δ
7.56−7.48 (m, 2H, Ar), 7.38−7.30 (m, 2H, Ar), 7.29−7.23 (m, 1H,
Ar), 6.60 (s, 1H, C = CH), 4.24−4.16 (m, 4H, 2xCH2CH3), 3.79 (dq,
J = 9.4, 7.0 Hz, 1H, CH2CH3), 3.49 (dq, J = 9.3, 7.0 Hz, 1H,
CH2CH3), 2.90 (d, J = 15.3 Hz, 1H, CCH2C), 2.63 (d, J = 15.4 Hz,
1H, CCH2C), 2.58 (dd, J = 12.9, 7.1 Hz, 1H, (EtO2C)2CCH2CH),
2.28 (dd, J = 12.9, 11.3 Hz, 1H, (EtO2C)2CCH2CH), 2.14 (dtd, J =
10.9, 7.2, 3.4 Hz, 1H, CH2CHCH2), 1.88 (dd, J = 11.4, 7.4 Hz, 1H,
CHCH2COEt), 1.81 (dd, J = 11.4, 3.4 Hz, 1H, CHCH2COEt), 1.26
(t, J = 7.1 Hz, 3H, CH2CH3), 1.25 (t, J = 7.1 Hz, 3H, CH2CH3), 1.15
(t, J = 7.1 Hz, 3H, CH2CH3); 13C{1H} NMR (101 MHz, CDCl3) δ
172.6 (CO), 171.1 (CO), 146.8 (C), 133.9 (CH), 133.2 (C), 128.8
(2xCH), 127.9 (CH), 124.8 (2xCH), 114.8 (C), 91.1 (C), 62.9 (C),
62.6 (CH2), 61.9 (CH2), 61.7 (CH2), 49.0 (CH), 39.8 (CH2), 37.2
(CH2), 36.4 (CH2), 15.4 (CH3), 14.2 (CH3), 14.2 (CH3). IR (Neat):
2985, 2917, 2849, 1730 cm−1. Anal. Calcd for C23H28O6 (400.19 g/
mol): C, 68.98; H, 7.05%. Found: C, 69.11; H, 7.23%.
Diethyl (3aS*,6S*,7aR*)-6-Ethoxy-7a-methyl-5-phenyl-1,6,7,7a-
tetrahydro-3a,6-epoxyindene-2,2(3H)-dicarboxylate, 6b. It was
obtained from 3l (42 mg, 0.10 mmol) following the general
procedure for cycloisomerization reactions with Cp*RuCl(cod) and
purified by flash column chromatography (Hexane/AcOEt, 19:1).
NOESY spectra showed cross-peak between the CCH3 and the
olefinic proton. Thus, the titled compound was assigned as
133.1 (C), 129.9 (CH), 127.8 (CH), 119.8 (CH), 60.5 (CH2), 54.7
(CH2), 51.4 (CH2), 33.1 (C), 33.0 (CH), 22.9 (CH2), 21.7 (CH3),
15.4 (CH3), 14.4 (CH3). IR (Neat): 2982, 2924, 2853, 1731 cm−1.
Anal. Calcd for C18H23NO4S (349.13 g/mol): C, 61.87; H, 6.63%.
Found: C, 62.03; H, 6.71%
Ethyl (E)-3-(3-Tosyl-3-azabicyclo[4.1.0]heptan-1-yl)acrylate, 5i.
It was obtained from 3i (42 mg, 0.12 mmol) following the general
procedure for cycloisomerization reactions with Cp*RuCl(cod) and
purified by flash column chromatography (Hexane/AcOEt, 8:1).
Colorless oil (26 mg, 0.08 mmol, 64%); 1H NMR (400 MHz,
CDCl3): δ 7.62 (d, J = 8.3 Hz, 2H, Ar), 7.30 (d, J = 7.9 Hz, 2H, Ar),
6.14 (d, J = 11.4 Hz, 1H, CHCHCO2), 5.81 (d, J = 11.5 Hz, 1H,
CHCHCO2), 4.18−4.08 (m, 2H, CH2CH3), 3.80 (dd, J = 11.2, 1.5
Hz, 1H, NCH2C), 3.36−3.28 (m, 1H, CCH2CH2), 2.87 (d, J = 11.2
Hz, 1H, NCH2C), 2.62 (ddd, J = 11.8, 10.3, 5.6 Hz, 1H, CCH2CH2),
2.42 (s, 3H, CCH3), 2.13−2.02 (m, 1H, CCH2CH2), 1.92−1.82 (m,
1H, CCH2CH2), 1.25 (t, J = 7.1 Hz, 3H, CH2CH3), 1.14−1.05 (m,
1H, CH2CH), 0.91 (dd, J = 6.0, 4.9 Hz, 1H, CH2 cyclopropane), 0.78
(dd, J = 9.4, 4.9 Hz, 1H, CH2 cyclopropane); 13C{1H} NMR (101
MHz, CDCl3) δ 165.5 (CO), 148.8 (CH), 143.4 (C), 134.4 (C),
129.8 (2xCH), 127.6 (2xCH), 123.6 (CH), 60.4 (CH2), 47.9 (CH2),
42.8 (CH2), 23.5 (CH2), 21.7 (CH3), 21.0 (C), 18.8 (CH), 18.3
(CH2), 14.3 (CH3). IR (Neat): 2988, 2923, 2852, 1721, 1637 cm−1.
Anal. Calcd for C18H23NO4S (349.13 g/mol): C, 61.87; H, 6.63%.
Found: C, 61.74; H, 6.76%.
Ethyl (E)-3-(3-Tosyl-3-azabicyclo[5.1.0]octan-1-yl)acrylate, 5j. It
was obtained from 3j (60 mg, 0.17 mmol) following the general
procedure for cycloisomerization reactions with Cp*RuCl(cod) and
purified by flash column chromatography (Hexane/AcOEt, 9:1). Pale
yellow oil (35 mg, 0.10 mmol, 52%). 1H NMR (400 MHz, CDCl3): δ
7.67 (d, J = 8.0 Hz, 2H, Ar), 7.31 (d, J = 8.0 Hz, 2H, Ar), 6.70 (d, J =
15.9 Hz, 1H, CHCHCO2), 6.03 (d, J = 15.9 Hz, 1H, CH
CHCO2), 4.23−4.15 (m, 1H, NCH2C), 4.18 (q, J = 7.0 Hz, 2H,
CH2CH3), 3.59−3.48 (m, 1H, NCH2CH2), 2.72−2.61 (m, 1H,
NCH2CH2), 2.55 (d, J = 14.3 Hz, 1H, NCH2C), 2.43 (s, 3H, CCH3),
2.29−2.19 (m, 1H, CH2CH), 1.79−1.65 (m, 2H, CH2CH2CH2),
1.31−1.23 (m, 1H, CHCH2), 1.29 (t, J = 7.1 Hz, 3H, CH2CH3),
1.15−1.09 (m, 1H, CH2CH), 1.13 (dd, J = 8.6, 5.1 Hz, 1H, CH2
cyclopropane), 0.93 (t, J = 5.7 Hz, 1H, CH2 cyclopropane); 13C{1H}
NMR (101 MHz, CDCl3) δ 167.3 (CO), 154.0 (CH), 143.6 (C),
1
(3aS*,6S*,7aR*). Colorless oil (33 mg, 0.08 mmol, 79%); H NMR
(400 MHz, CDCl3): δ 7.55−7.51 (m, 2H, Ar), 7.37−7.30 (m, 2H,
Ar), 7.29−7.21 (m, 1H, Ar), 6.55 (s, 1H, CHC), 4.25−4.20 (m,
4H, 2xCH2CH3), 3.75 (dq, J = 9.4, 7.1 Hz, 1H, CH2CH3), 3.44 (dq, J
= 9.4, 7.0 Hz, 1H, CH2CH3), 2.95 (d, J = 15.2 Hz, 1H, CCH2CCH),
2.85 (d, J = 13.8 Hz, 1H, CCH2CCH3), 2.79 (d, J = 15.2 Hz, 1H,
(EtO2C)2CCH2CCH), 2.36 (d, J = 13.8 Hz, 1H, (EtO2C)2CCH2-
CCH3), 2.20 (d, J = 11.3 Hz, 1H, CH3CCH2COEt), 1.53 (d, J = 11.3
Hz, 1H, CH3CCH2COEt), 1.25 (t, J = 7.1 Hz, 3H, CH2CH3), 1.24 (t,
J = 7.1 Hz, 3H, CH2CH3), 1.11 (t, J = 7.1 Hz, 3H, CH2CH3), 0.83 (s,
3H, CCH3); 13C{1H} NMR (101 MHz, CDCl3) δ 173.0 (CO), 171.6
(CO), 147.4 (C), 133.0 (C), 131.8 (CH), 128.7 (2xCH), 127.9
(CH), 125.0 (2xCH), 114.1 (C), 93.1 (C), 62.2 (CH2), 62.0 (CH2),
61.8 (CH2), 60.8 (C), 55.6 (C), 47.1 (CH2), 47.1 (CH2), 35.0
(CH2), 24.1 (CH3), 15.4 (CH3), 14.2 (2xCH3). IR (Neat): 2982,
2915, 2849, 1730 cm−1. Anal. Calcd for C24H30O6 (414.20 g/mol): C,
69.55; H, 7.30%. Found: C, 69.47; H, 7.13%.
Tetraethyl (E)-6,7-Bis((Z)-3-ethoxy-3-oxo-2-phenylprop-1-en-1-
yl)-2,11-dimethyldodeca-1,6,11-triene-4,4,9,9-tetracarboxylate,
7a. It was obtained from 3l (41 mg, 0.10 mmol) following the general
procedure for cycloisomerization reactions with Cp*RuCl(cod) at 50
°C and stirred overnight. The titled compound was purified by flash
column chromatography (Hexane/AcOEt, 19:1). Colorless oil (39
1
mg, 0.05 mmol, 95%); H NMR (400 MHz, CDCl3): δ 7.55−7.52
(m, 4H, Ar), 7.32 (t, J = 7.8 Hz, 4H, Ar), 7.17−7.11 (m, 2H, Ar), 6.27
(s, 2H, 2xCCH), 4.94 (t, J = 1.8 Hz, 2H, 2xCCH2), 4.85 (s, 2H,
2xCCH2), 4.24 (q, J = 7.2 Hz, 4H, 2xCH2CH3), 4.20 (q, J = 7.2
Hz, 8H, 4xCH2CH3), 3.26 (s, 4H, 2xCCCH2), 2.73 (s, 4H,
2xCH2CCH2), 1.72 (s, 6H, 2xCCH3), 1.39 (t, J = 7.1 Hz, 6H,
2xCH2CH3), 1.26 (t, J = 7.1 Hz, 12H, 4xCH2CH3); 13C{1H} NMR
(101 MHz, CDCl3) δ 171.0 (4xCO), 154.6 (2xCO), 141.2 (2xC),
140.7 (2xC), 132.7 (2xC), 128.6 (4xCH), 125.6 (4xCH), 125.4
(2xCH), 116.2 (2xCH2), 109.0 (2xCH), 100.5 (2xC), 68.1 (2xCH2),
61.6 (4xCH2), 57.0 (2xC), 39.8 (2xCH2), 31.2 (2xCH2), 23.7
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(2xCH3), 15.4 (2xCH3), 14.2 (4xCH3). IR (Neat): 2978, 2940, 1734
cm−1. Anal. Calcd for C48H60O12 (828.41 g/mol): C, 69.55; H, 7.30%.
Found: C, 69.39; H, 7.21%.
REFERENCES
■
(1) General reviews on cyclopropane chemistry: (a) Vicente, R.
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(3) Selected recent examples. Rh catalyzed: (a) Edwards, A.; Rubina,
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Prochiral 1-Arylcycloprop-2-ene-1-carboxylic Acid Derivatives. Chem.
- Eur. J. 2018, 24, 1394−1403. (b) Dian, L.; Marek, I. Rhodium-
Catalyzed Arylation of Cyclopropenes Based on Asymmetric Direct
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Int. Ed. 2018, 57, 3682−3686. (c) Sawano, T.; Hashizume, M.;
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(d) Sherrill, W. M.; Rubin, M. Rhodium-Catalyzed Hydroformylation
of Cyclopropenes. J. Am. Chem. Soc. 2008, 130, 13804−13809. Au
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M.; Lee, A. Gold(I)-Catalyzed Addition of Thiols and Thioacids to
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(f) Young, P. C.; Hadfield, M. S.; Arrowsmith, L.; MacLeod, K. M.;
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Gold(I)-Catalyzed Indole Additions to 3,3-Disubstituted Cyclo-
propenes. Org. Lett. 2012, 14, 898−901. (g) Hadfield, M. S.; Bauer,
J. T.; Glen, P. E.; Lee, A. Gold(I)-Catalysed Alcohol Additions to
Cyclopropenes. Org. Biomol. Chem. 2010, 8, 4090−4095. Pd
catalyzed: (h) Trofimov, A.; Rubina, M.; Rubin, M.; Gevorgyan, V.
Highly Diastereo- and Regioselective Transition Metal-Catalyzed
Tetraethyl (E)-7,8-Bis((Z)-3-ethoxy-3-oxo-2-phenylprop-1-en-1-
yl)-2,13-dimethyltetradeca-2,7,12-triene-5,5,10,10-tetracarboxy-
late, 7b. It was obtained from 3m (41 mg, 0.10 mmol) following the
general procedure for cycloisomerization reactions with Cp*RuCl-
(cod) and purified by flash column chromatography (Hexane/AcOEt,
1
19:1). Colorless oil (30 mg, 0.04 mmol, 73%); H NMR (400 MHz,
CDCl3): δ 7.54 (d, J = 7.5 Hz, 4H, Ar), 7.32 (t, J = 7.7 Hz, 4H, Ar),
7.14 (t, J = 7.4 Hz, 2H, Ar), 6.25 (s, 2H, 2xCCHC), 5.05 (t, J = 7.4
Hz, 2H, 2xCCHCH2), 4.27−4.16 (m, 12H, 6xCH2CH3), 3.20 (s,
4H, 2xCCH2C), 2.62 (d, J = 7.4 Hz, 4H, 2xCCH2CH), 1.72 (s, 6H,
2xCCH3), 1.61 (s, 6H, 2xCCH3), 1.38 (t, J = 7.1 Hz, 6H,
2xCH2CH3), 1.26 (t, J = 7.1 Hz, 12H, 4xCH2CH3); 13C{1H} NMR
(101 MHz, CDCl3) δ 170.9 (4xCO), 154.6 (2xCO), 141.2 (2xC),
135.8 (2xC), 132.7 (2xC), 128.6 (4xCH), 125.6 (4xCH), 125.4
(2xCH), 117.7 (2xCH), 108.8 (2xCH), 100.6 (2xC), 68.1 (2xCH2),
61.5 (4xCH2), 57.6 (2xC), 31.1 (2xCH2), 30.9 (2xCH2), 26.3
(2xCH3), 18.2 (2xCH3), 15.3 (2xCH3), 14.2 (4xCH3). IR (Neat):
2980, 2940, 1733 cm−1. Anal. Calcd for C50H64O12 (856.44 g/mol):
C, 70.07; H, 7.53%. Found: C, 70.25; H, 7.69%.
Tetraethyl (E)-8,9-Bis((Z)-3-ethoxy-3-oxo-2-phenylprop-1-en-1-
yl)hexadeca-1,8,15-triene-6,6,11,11-tetracarboxylate, 7c. It was
obtained from 3n (25 mg, 0.06 mmol) following the general
procedure for cycloisomerization reactions with Cp*RuCl(cod) and
purified by flash column chromatography (Hexane/AcOEt, 19:1).
Colorless oil (22 mg, 0.03 mmol, 86%); 1H NMR (400 MHz,
CDCl3): δ 7.53 (d, J = 7.7 Hz, 4H, Ar), 7.32 (t, J = 7.6 Hz, 4H, Ar),
7.14 (t, J = 7.4 Hz, 2H, Ar), 6.25 (s, 2H, 2xCHC), 5.78 (ddt, J =
16.9, 10.2, 6.6 Hz, 2H, 2xCHCH2), 5.01 (dd, J = 17.2, 1.8 Hz, 2H,
2xCHCHH), 4.95 (dd, J = 10.3, 1.9 Hz, 2H. 2xCHCHH), 4.27−
4.17 (m, 12H, 6xCH2CH3), 3.22 (s, 4H, 2xCCH2C), 2.06 (q, J = 7.1
Hz, 4H, 2xCH2CHCH2), 1.92−1.84 (m, 4H, 2xCCH2CH2), 1.43−
1.32 (m, 4H, 2xCH2CH2CH2), 1.39 (t, J = 7.1 Hz, 6H, 2xCH2CH3),
1.27 (t, J = 7.1 Hz, 12H, 4xCH2CH3); 13C{1H} NMR (101 MHz,
CDCl3) δ 171.1 (4xCO), 154.7 (2xCO), 141.1 (2xC), 138.2 (2xCH),
132.8 (2xC), 128.6 (4xCH), 125.6 (4xCH), 125.4 (2xCH), 115.1
(2xCH2), 108.7 (2xCH), 100.7 (2xC), 68.1 (2xCH2), 61.5 (4xCH2),
57.7 (2xC), 34.0 (2xCH2), 31.7 (2xCH2), 31.3 (2xCH2), 23.6
(2xCH2), 15.4 (2xCH3), 14.2 (4xCH3). IR (Neat): 2980, 2942, 1732
cm−1. Anal. Calcd for C50H64O12 (856.44 g/mol): C, 70.07; H, 7.53%.
Found: C, 69.96; H, 7.39%.
ASSOCIATED CONTENT
* Supporting Information
■
S
The Supporting Information is available free of charge on the
ACS Publications website at DOI: 10.1021/acs.joc.8b02849.
1
Copies of H, 13C NMR spectra of all products and 2D
spectra of new products (PDF)
AUTHOR INFORMATION
Corresponding Author
*E-mail: jpercas@ceu.es.
■
ORCID
́
Javier Perez-Castells: 0000-0002-7256-0723
Notes
The authors declare no competing financial interest.
ACKNOWLEDGMENTS
■
Funding of this project by Spanish MINECO, grant No.
CTQ2015-64624-R (Co-funded by European Regional Devel-
opment Fund/European Social Fund, “Investing in your
future”) and FUSP-CEU (PC17/17) is acknowledged. A.L-R.
́
thanks the Fundacion San Pablo-CEU for a predoctoral
fellowship.
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