Unusual manganese(III)-mediated oxidative free-radical additions of Meldrum's acid and dimethyl malonate to benzonorbornadiene and oxabenzonorbornadiene

Article abstract of DOI:10.1016/j.tet.2016.11.061

Benzonorbornadiene and 7-oxabenzonorbornadiene were reacted with Meldrum's acid and dimethyl malonate in the presence of Mn(OAc)₃and Cu(OAc)₂in acetic acid. The reaction of benzonorbornadiene with Meldrum's acid gave a naphthalene derivative whereas the reaction with dimethyl malonate formed rearranged products derived from a carbocation intermediate. However, the reaction of 7-oxabenzonorbornadiene with Meldrum's acid gave two nonrearranged products. On the other hand, the reaction with dimethyl malonate unexpectedly formed a dihydronapthalene derivative with an unusual structure. The mechanism for the formation of the products is discussed.

Full text of DOI:10.1016/j.tet.2016.11.061

Accepted Manuscript
Unusual manganese(III)-mediated oxidative free-radical additions of Meldrum's acid
and dimethyl malonate to benzonorbornadiene and oxabenzonorbornadiene
Raşit Çalışkan, Neslihan Nohut, Özlem Yılmaz, Ertan Sahin, Metin Balci
PII:
S0040-4020(16)31223-6
10.1016/j.tet.2016.11.061
TET 28275
DOI:
Reference:
To appear in: Tetrahedron
Received Date: 21 September 2016
Revised Date: 9 November 2016
Accepted Date: 21 November 2016
Please cite this article as: Çalışkan R, Nohut N, Yılmaz E, Sahin E, Balci M, Unusual manganese(III)-
mediated oxidative free-radical additions of Meldrum's acid and dimethyl malonate to
benzonorbornadiene and oxabenzonorbornadiene, Tetrahedron (2016), doi: 10.1016/j.tet.2016.11.061.
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Graphical Abstract
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Unusual Manganese(III)-Mediated Oxidative Free-Radical
Additions of Meldrum’s acid and Dimethyl Malonate to
Benzonorbornadiene and Oxabenzonorbornadiene
Raşit Çalışkan,a,* Neslihan Nohut,a Özlem Yılmaz,a Ertan Sahin,b and Metin Balcic,*
aDepartment of Chemistry, Süleyman Demirel University, 32260 Isparta, Turkey
bDepartment of Chemistry, Atatürk University, 25240, Erzurum, Turkey
cDepartment of Chemistry, Middle East Technical University, 06800 Ankara, Turkey
Abstract: Benzonorbornadiene and 7-oxabenzonorbornadiene were reacted with Meldrum’s
acid and dimethyl malonate in the presence of Mn(OAc)3 and Cu(OAc)2 in acetic acid. The
reaction of benzonorbornadiene with Meldrum’s acid gave a naphthalene derivative whereas
the reaction with dimethyl malonate formed rearranged products derived from a carbocation
intermediate. However, the reaction of 7-oxabenzonorbornadiene with Meldrum’s acid gave
two nonrearranged products. On the other hand, the reaction with dimethyl malonate
unexpectedly formed a dihydronapthalene derivative with an unusual structure. The
mechanism for the formation of the products is discussed.
Keywords: Manganase(III) acetate; Copper(II) acetate; Cycloaddition; Oxidation;
Dihydrofurans; Rearrangement; Benzonorbornadiene; Oxabenzonorbornadiene
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1. Introduction
The generation of carbon radicals using transition metal salts such as Mn(OAc)3,
Cu(OAc)2, Pb(OAc)4, (NH4)2Ce(NO3)6 and their addition to carbon-carbon double bonds is a
valuable method for C- C bond formation.1 Mn(OAc)3, a one-electron oxidant, is considered
one of the most popular reagents in the field of free-radical chemistry. It has found extensive
use in the construction of a wide range of molecules with interesting properties.2 It is well
known that 1,3-dicarbonyl compounds undergo [3+2] cycloaddition to alkenes in the presence
of Mn(OAc)3 to form dihydrofurans,3 which are important building blocks of natural products
and pharmaceuticals.
Generally, an oxidatively or reductively genareted radical 2 formed from a 1,3-dicarbonyl
compound 1, regioselectively attacks an electron-rich double bond forming a new radical 3
(Scheme 1).4 The radical may be terminated or undergo a cyclization reaction.
Scheme 1. General mechanism for the formation of 2,3-dihydrofuran derivatives
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Heiba and Dessau5 proposed oxidation of radical 3 to a cation 4 followed by cyclization
and proton loss to give dihydrofuran derivative 5. However, Fristad et al.6 proposed an
alternative route where the radical 3 first undergoes a cyclization reaction to form a new
radical 6 followed by oxidation and proton elimination to produce 5. In order to address the
question of at which stage the cyclization and oxidation take place we incorporated possible
intermediates such as 3 and/or 4 in a bicyclic system.7 It is well established that a radical
intermediate of type 8 does not undergo rapid rearrangement.8 However, a cation of type 9 has
a great tendency to undergo rearrangement and to form rearranged products (Scheme 2).
Scheme 2. Possible structures formed by addition of a 1,3-dicarbonyl compound to a benzo-
norbornadiene system.
For this reason, benzonorbornadiene (7) and acetylacetone (10) were reacted in the
presence of Mn(OAc)3 and Cu(OAc)2 (Scheme 3).7b The dihydrofuran adduct 11 was obtained
as the major product whereas the rearranged product 12 was formed in 16% yield. The
formation of 11 was rationalized by a fast intramolecular capture of the radical with a
structure similar to 8. On the other hand, a nonclassical carbocation may also responsible for
the formation of product 11. The reaction of homobenzonorbornadiene 13 with acetylacetone
under the same reaction conditions resulted in the formation of a rearranged product 14 in
66% yield.7a
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Scheme 3. Reaction of benzonorbornadiene (7) and homobenzonorbornadiene (13) with
acetylacetone (10) in the presence of Mn(OAc)3 and Cu(OAc)2.
To gain more insight into the mechanism of the cycloaddition of 1,3-dicarbonyl
compounds to bicyclic systems in the presence of Mn(OAc)3 and Cu(OAc)2 we reacted
benzonorbornadiene (7) and oxabenzonorbornadiene (15) with Meldrum’s acid (16) and
dimethyl malonate (17). Herein we describe our results.
2. Results and Discussion
The starting materials, benzonorbornadiene (7)9 and oxabenzonorbornadiene (15)10 were
synthesized as described in the literature. The reaction of benzonorbornadiene (7) with 16 in
the presence of Mn(OAc)3 and Cu(OAc)2 in acetic acid at 50 °C gave two separable products:
a rearranged product 18 with a naphthalene skeleton and 1-naphthaldehyde (19) (Scheme 4).
The structure of 18 was unambiguously characterized by NMR spectra. To test whether the
minor product, 1-naphthaldehyde (19) is a primary or a secondary product, the rearranged
product 18 was subjected to a Mn(OAc)3-oxidation reaction under the same reaction
conditions. The rearranged product 18 was smoothly transferred into 1-naphthaldehyde (19)
(Scheme 4).
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Scheme 4. Reaction of benzonorbornadiene (7) with 16 in the presence of Mn(OAc)3 and
Cu(OAc)2.
For the formation of rearranged product 18 we suggest the following mechanism as
depicted in Scheme 5. The rearranged product 23 can be formed by the addition of the
initially formed radical derived from 16 to the C=C double bond in 7 forming a new radical
20 followed by further oxidation, rearrangement, and loss of H+ to give 23. Further oxidation
of 23 to 25 followed by a cleavage of the bridge carbon-carbon bond can result in the
formation of a stable benzylic/allylic cation 26. Aromatization of 26 can generate the final
product 18 (Scheme 5). A similar tandem oxidation reaction with Mn(OAc)3 was recently
observed by the reaction of homobenzonorbornadiene 13 with acetylacetone as depicted in
Scheme 3. All this information indicates that a cation 21 is formed as an intermediate that has
a great tendency for rearrangement.
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Scheme 5. Proposed mechanism for the formation of 18.
When the scope of this reaction was expanded to oxabenzonorbornadiene 15 using the
same methodology, a cyclopropane derivative11 27 was isolated as the major product in 52%
yield besides the exo-cyclic methylene derivative 28 (Scheme 6).
Scheme 6. Reaction of oxabenzonorbornadiene (15) with 16 in the presence of Mn(OAc)3 and
Cu(OAc)2.
The completely different behavior of the oxabenzonorbornadiene 15 may be attributed to
the presence of the bridge oxygen atom. We assume that both of these products, 27 and 28,
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are formed from the initially formed classical carbocation 29. Probably, this cation 29 has no
tendency to undergo a Wagner-Meerwein type rearrangement due to the presence of an
electron-withdrawing oxygen atom that retards the involvement of the neighboring σ-bond to
form a nonclassical carbocation. Fast attack by the enol functionality of 29 results in the
formation of cyclopropane derivative 27. On the other hand, cation 29 can be further
stabilized by a 1,2-hydrogen shift, thus forming a new cation 30, which will form the exo-
cyclic methylene derivative 28 (Scheme 7). and Wagner-Meerwein rearrangements, etc., are
all sensible. In scheme 7, the pathway from cation 29 to final product 28 is shown as
proceeding via a [1,2]-hydride shift to 30. The final compound may also be formed by lost of
H+ from 29 to regenerate the endocyclic C=C double bond in the oxabenzonorbornadiene
structure. In the next step alkene can tautomerize to final product 28 via an extended enol
tautomer.
Scheme 7. Proposed mechanism for the formation of 27 and 28.
To gain more insight into the formation mechanism of the products we used dimethyl
malonate (17) instead of a cyclic diester 16. The reaction of benzonorbornadiene (7) with
dimethyl malonate (17) and Mn(OAc)3 in the presence of Cu(OAc)2 gave two separable
products, 31 and 32, in yields of 45% and 36%, respectively (Scheme 8).
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Scheme 8. Reaction of benzonorbornadiene (7) with dimethyl malonate (17) in the presence
of Mn(OAc)3 and Cu(OAc)2.
It was interesting to note that no trace of the expected dihydrofuran derivatives was
formed. The initially formed radical 33, formed by the addition of dimethyl malonate,
undergoes fast oxidation with Cu(OAc)2 to form a nonclassical cation 34, which can be
stabilized by the nucleophilic attack of the acetate anion to form 31. The rearrangement of the
nonclassical cation 34 to the classical cation 35 followed by H+ elimination results in the
formation of 32 (Scheme 9).
Scheme 9. Proposed mechanism for the formation of 30 and 31.
Finally, the reaction of oxabenzonorbornadiene (15) with dimethyl malonate (17) in the
presence of Mn(OAc)3 and Cu(OAc)2 gave the rearranged product 36 in a yield of 56%
(Scheme 10). The exact structure of 36 was determined by X-ray crystallographic analysis
(Figure 1). The mechanism for the formation of this compound is not known.
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Scheme 10. Reaction of oxabenzonorbornadiene (15) with dimethyl malonate (17) in the
presence of Mn(OAc)3 and Cu(OAc)2.
All these experiments show that 1,3-dicarbonyl compounds such as Meldrum’s acid and
dimethyl malonate having ester carbonyl functionalities do not undergo a cyclization reaction
to form dihydrofuran derivatives, at least in these bicyclic systems.12 Radicals can be
classified as electrophilic/nucleophilic. The initially formed radicals such as 20 and 33 are
nucleophilic.13 Since the carbonyl oxygen atoms in 16 and 17 are also nucleophilic,
cyclization is not likely. The carbocations formed after oxidation of the radicals can form
cyclization products. However, the fact that cyclization products with dihydrofuran structure
are not observed can be attributed to the increased tendency of the formed cations for
Wagner-Meerwein type rearrangement.
Figure 1. Thermal ellipsoid drawings of compound 36.
3. Conclusion
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The primary goal of this work was to examine the reactivity of 1,3-dicarbonyl
compounds having ester functionalities by the addition to bicyclic olefins in the presence of
Mn(OAc)3 and Cu(OAc)2. 1,3-Dicarbonyl compounds with ketone functional groups form
mainly rearranged or nonrearranged dihydrofuran derivatives. The reaction of
benzonorbornadiene (7) with Meldrum’s acid (16) gave a naphthalene derivative 18 after
tandem oxidation reaction. On the other hand, the reaction of 7 with 17 gave rearranged
products indicating that the initially formed radical first undergoes oxidation before
undergoing further reactions. However, the reaction of 7-oxabenzonorbornadiene (15) with
Meldrum’s acid (16) gave nonrearranged products 27 and 28. On the other hand, the reaction
with dimethyl malonate unexpectedly formed the compound 36 with an unusual structure. The
mechanism for the formation of this compound is not known. Generally speaking, 1,3-
dicarbonyl compounds with ester functionalities do not have a tendency to generate
dihydrofuran addition products, at least in these chosen systems.
4. Experimental Section
4.1. General Methods. NMR spectra were recorded on a 400 MHz spectrometer. Infrared
(IR) spectra were recorded in the range 4000-600 cm-1 via ATR diamond. Melting points
were determined using a melting point apparatus and were uncorrected. Column
chromatography was performed on silica gel (60-mesh), TLC was carried out on 0.2 mm
silica gel 60 F254 analytical aluminum plates.
4.2. General procedure for addition of 1,3-dicarbonyl compounds to alkenes. A solution of
1,3-diketone (5 mmol) and olefin (5 mmol) in 20 mL of a glacial acetic acid in a flame-dried
flask was heated to 50 °C under nitrogen. Then 10 mmol of Mn(OAc)3·2H2O and 2 mmol of
Cu(OAc)2 were added to the solution. The dark brown solution became lighter as the Mn(III)
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was reduced. When the reaction was complete, the solution was colorless to light blue-green
with a variable amount of white precipitate present. Water was added to the reaction mixture
and the precipitate was dissolved. The solution was extracted with methylene chloride. The
combined organic layers were washed several times with saturated NaHCO3 solution and then
water and dried (MgSO4). Evaporation of the solvent gave the crude compound, which was
purified by crystallization or column chromatography.
4.3. Oxidative addition of Meldrum’s acid (16) to benzonorbornadiene (7) in the presence of
Mn(OAc)3 and Cu(OAc)2. Meldrum’s acid (16) (0.72 g, 5 mmol), benzonorbornadiene (7)
(0.71 g, 5 mmol), Mn(OAc)3·2H2O (2.7 g, 10 mmol), and Cu(OAc)2·2H2O (0.18 g, 1 mmol)
in 30 mL of glacial acetic acid were reacted for 2 h as described above. The chromatography
of the residue on silica gel (37.4 g, hexane/EtOAc; 4:1) gave 0.81 g of 18 (58%) and 0.085 g
of 19 (11%).
4.3.1. Data for 2,3-dimethyl-5-(1-naphthylmethylene)1,3-dioxane-4,6-dione (18): Yellow
crystals, mp 130–132 °C (Lit. mp, 125–126 °C14); 1H-NMR (400 MHz, CDCl3)
δ 9.15 (s, 1H)
13
δ
8.02-7.90 (m, 3H), 7.62-7.50 (m, 4H), 1.79 (s, 6H); C-NMR (100 MHz, CDCl3)
162.7,
159.4, 156.4, 133.3, 133.2, 131.7, 129.9, 129.1, 129, 127.7, 126.6, 124.9, 123.6, 117.7, 104.8,
27.8.
4.4. Oxidative addition of Meldrum’s acid (16) to 7-oxabenzonorbornadiene (15) in the
presence of Mn(OAc)3 and Cu(OAc)2. Meldrum’s acid (16) (0.72 g, 5 mmol), 7-
oxabenzonorbornadiene (15) (0.72 g, 5 mmol), Mn(OAc)3·2H2O (2.7 g, 10 mmol), and
Cu(OAc)2·2H2O (0.18 g, 1 mmol) in 30 mL of glacial acetic acid were reacted for 2 h as
described above. The chromatography of the residue on silica gel (82.5 g, 4:1 hexane/EtOAc)
gave 0.743 g of 27 (52%) and 0.242 g of 28 (17%).
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4.4.1.
rel-(1aS(R),2R(S),7S(R),7aS(R))-2',2'-dimethyl-1a,2,7,7a-tetrahydrospiro[2,7-epoxy-
cyclopropa-[b]-naphthalene-1,5'-[1,3]dioxane]-4',6'-dione (27). Colorless crystals, mp 132-
133 °C; 1H-NMR (400 MHz, CDCl3)
δ
7.35 (A-part of AA'BB' system, 2H), 7.12 (B-part of
13
AA'BB' system, 2H), 5.62 (s, 2H), 2.52 (s, 2H), 1.82 (s, 6H); C-NMR (100 MHz, CDCl3)
δ
165.1, 162.4, 145.4, 126.0, 121.1, 105.2, 78.6, 43.2, 41.3, 27.1; IR (KBr, cm-1) 3117, 2925,
2854, 1736, 1705, 1664, 1471, 1285, 1017, 951, 741, 498; HRMS-TOF [M - H]ꢀ: Calcd for
C16H13O5 285.0768, found: 285.0769.
4.4.2. 5-((1S(R),4R(S))-5-(3,4-dihydro-1,4-epoxynaphthalen-2(1H)-2,2-dimethyl-1,3-dioxane-
4,6-dione (28):
Colorless crystals, mp 117-118 °C; 1H-NMR (400 MHz, CDCl3)
δ 7.6-7.2 (m, aromatic, 4H),
6.64 (s, 1H), 5.59 (d, J = 4.2 Hz, 1H), 3.19 (dd, A-part of AB system, J = 18.4 and 4.2 Hz,
13
1H), 3.07 (d, B-part of AB system, J = 18.4 Hz, 1H), 1.78 (s, 3H), 1.69 (s, 3H); C-NMR
(100 MHz, CDCl3)
δ 178.8, 159.7, 159.5, 144.8, 137.8, 127.4, 126.7, 121.3, 118.8, 109.6,
103.7, 81.7, 76.8, 39.8, 26.6, 26.4; IR (KBr, cm-1) 3114, 2958, 2796, 1741, 1667, 1425, 1219,
1058, 760, 692, 548; HRMS Calcd for (C16H13O5) [M - H]ꢀ: 285.0768; Found: 285.0770.
4.5. Oxidative addition of dimethyl malonate (17) to benzonorbornadiene (7) in the presence
of Mn(OAc)3 and Cu(OAc)2. Dimethyl malonate (17) (0.66 g, 5 mmol), benzonorbornadiene
(7) (0.71 g, 5 mmol), Mn(OAc)3·2H2O (2.7 g, 10 mmol), and Cu(OAc)2·2H2O (0.18 g, 1
mmol) in 30 mL of glacial acetic acid were reacted for 16 h as described above. The
chromatography of the residue on silica gel (37.5 g, 4:1 hexane/EtOAc) gave 0.489 g of 31
(45%) and 0.597 g of 32 (36%).
4.5.1. Dimethyl 2-(1,4-dihydro-1,4-methanonaphthalen-9-yl)malonate (32). Pale yellow oil;
1H-NMR (400 MHz, CDCl3)
δ
7.11 (A-part of AA'BB' system, 2H), 6.86 (B- part of AA'BB'
system, 2H), 6.55 (s, 2H), 3.75 (s, 2H), 3.72 (d, J = 11.6 Hz, 1H), 3.68 (s, 6H), 3.10 (d, J =
11.6 Hz, 1H); 13C-NMR (100 MHz, CDCl3)
δ
169.80, 151.2, 140.3, 125.28, 122.4, 77.1
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(Overlapping CDCl3 peaks), 53.7, 53.1. 52.9; IR (KBr, cm-1): 3044, 2961, 2870, 1726, 1682,
1453, 1383, 1275, 1089, 759, 711; HRMS-TOF [M + Na]+- Calcd for C16H16O4Na 295.0946,
found: 295.0952.
4.5.2. Data for Dimethyl 2[(1R(S), 2R(S), 4S(R), 9S(RS))-2-(acetyloxy)-1,2,3,4-tetrahydro-
1,4- methanonaphthalen -9-yl]malonate (31): Colorless crystals, mp 103-105 °C ; 1H-NMR
(400 MHz, CDCl3)
δ 7.30-7.01 (m, Aromatic, 4H), 4.68 (dd, J = 7.2 and 3.1 Hz, 1H), 3.95 (d,
J = 12.2 Hz, 1H), 3.77 (s, 3H), 3.76 (s, 6H), 3.47 (s, 1H), 3.33 (bs, 1H), 2.73 (d, J = 12.2 Hz,
1H), 2.07 (s, 3H), 1.95 (dt, A-part of AB system, J = 13.4 and 3.1 Hz, 1H), 1.95 (dd, B-part of
13
AB system, J = 13.4 and 7.2 Hz, 1H); C-NMR (100 MHz, CDCl3)
δ 170.4, 168.9, 168.7,
148.1, 143.0, 126.7, 126.1, 122.4, 120.8, 75.7, 57.6, 52.5, 52.4, 51.2, 51.1, 45.2, 33.7, 21.1; IR
(KBr, cm-1) : 3054, 2961, 2875, 1720, 1451, 1403, 1375,1250, 1160, 754; HRMS Calcd for
(C18H21O6) [M + H]+: 333.1338; Found: 333.1338.
4.6. Oxidative addition of dimethyl malonate (17) to 7-oxabenzonorbornadiene in the
presence of Mn(OAc)3 and Cu(OAc)2. Dimethyl malonate (17) (0.66 g, 5 mmol), 7-
oxabenzonorbornadiene (15) (0.72 g, 5 mmol), Mn(OAc)3·2H2O (2.7 g, 10 mmol), and
Cu(OAc)2·2H2O (0.18 g, 1 mmol) in 30 mL of glacial acetic acid were reacted for 12 h as
described above. The chromatography of the residue on silica gel (82.4 g, 4:1 hexane/EtOAc)
gave 0.811 g of 36 (56%).
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4.6.1. Dimethyl 3-formyl-1-hydroxynaphthalene-2,2(1H)dicarboxylate (36). Colorless
1
crystals, mp 145-147 °C; H-NMR (400 MHz, CDCl3)
δ 9.62 (s, 1H), 7.79-7.65 (m, 1H),
7.55-7.45 (m, 1H), 7.40-7.35 (s, 1H), 7.35 (m, 2H), 5.45 (s, 1H), 4.51 (bs, 1H), 3.77 (s, 3H),
13
3.65 (s, 3H); C-NMR (100 MHz, CDCl3)
δ 189.7, 170.3, 169.9, 146.2, 139.5, 136.1, 132.6,
129.3, 129.2, 128.4, 124.7, 74.3, 58.8, 53.5, 53.2; IR (KBr, cm-1) 3539, 3027, 2974, 2699,
1728, 1682, 1657, 1410, 1366, 1255, 1124, 796, 532; HRMS-TOF [M + Na]+: Calcd for
C15H14O6Na 313.0688, found: 313.0697.
4.7. X-ray crystal structure analysis of 36. For the crystal structure determination, a single-
crystal of the compound 36 was used for data collection on a four-circle Rigaku R-AXIS
RAPID-S diffractometer (equipped with a two-dimensional area IP detector). Graphite-
monochromated Mo-Kα radiation (λ = 0.71073 Å) and oscillation scans with ∆w = 5° for one
image were used for data collection. The lattice parameters were determined by the least-
squares methods on the basis of all reflections with F2 > 2 (F2). Integration of the intensities,
σ
correction for Lorentz and polarization effects and cell refinement were performed using
CrystalClear (Rigaku/MSC Inc., 2005) software.15 The structures were solved by direct
methods using SHELXS-97 and refined by a full-matrix least-squares procedure using the
same program.16 All nonhydrogen atoms were refined anisotropically and H atoms were
positioned geometrically and refined using a riding model. The final difference Fourier maps
showed no peaks of chemical significance.
4.6.1. Crystal data for (36): C15H14O6, crystal system, space group: monoclinic, P21/n;
(no:14); unit cell dimensions: a = 10.4059 (6), b = 6.2340(3), c = 21.6724(12) Å, α= 90, β =
103.195(2), γ = 90°; volume: 1368.78 (7) Å3; Z = 4; calculated density: 1.41 g/cm3;
absorption coefficient: 0.110 mm-1; F(000): 608; θ-range for data collection 3.4–28.3°;
refinement method: full matrix least-square on F2; data/parameters: 2453/193; goodness-of-fit
on F2: 1.056; final R-indices [I > 2σ(I)]: R1 = 0.052, wR2 = 0.134; largest diff. peak and hole:
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0.260 and -0.200 e Å-3. Crystallographic data that were deposited in CSD under CCDC-
1484154 registration numbers contain the supplementary crystallographic data for this Letter.
These data can be obtained free of charge from the Cambridge Crystallographic Data Centre
(CCDC) via www.ccdc.cam.ac.uk/data_request/cif and are upon request to CCDC, 12 Union
Road, Cambridge, UK (fax: +441223 336033, e-mail: deposit@ccdc.cam.ac.uk).
Acknowledgements
Financial support from Süleyman Demirel University and the Turkish Academy of Sciences
(TUBA) is gratefully acknowledged.
Supplementary data
Supplementary data related to this article (1D and 2D NMR spectra of the products and (17
pages)) can be found in the online version, at http://dx.doi.org/......
References
(1) (a) Mondal, M.; Bora, U. RSC Adv. 2013, 3, 18716–18754. (b) Mondal, M. Synlett,
2013, 24, 137–138.
(2) For reviews on Mn(OAc)3 oxidation see: (a) Pan, X.-Q.; Zou, J.-P.; Zhang, W. Mol
Divers. 2009, 13, 421–438. (b) Demir, A. S.; Emrullahoglu, M. Curr. Org. Synth. 2007, 4,
321–350. (c) Snider, B. B. Chem. Rev. 1996, 96, 339–363. (d) Iqbal, J.; Bhatia, B.; Nayyar, N.
K. Chem. Rev. 1994, 94, 519–564. (e) Melikyan, G. G. Synthesis 1993, 833–850.
(3) For recent examples for Mn(OAc)3 mediated addition of 1,3-dicarbonyl compounds to
olefins see: (a) Liu, X.; Chen, X.; Mohr, J. T. Org. Lett. 2016, 18, 3182−3185. (b) Liu, X.;
Chen, X.; Mohr, J. T. Chem-Eur. J. 2016, 22, 2274–2277. (c) Chuang, C.-P.; Chen, Y.-J.
Tetrahedron 2016, 72, 1911–1918. (d) Matsumotoa, R.; Nishino, H Synth. Commun. 2015,
45, 1807–1816. (e) Chany, A.-C.; Marx, L. B.; Burton, J.W.Org. Biomol. Chem. 2015, 13,
9190–9193. (f) Li, P.; Zhao, J.; Xia, C.; Li, F. Org. Lett. 2014, 16, 5992–5295. (g) Yue, Y.;
16

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Zhang, Y.; Song, W.; Zhang, X.; Liu, J.; Zhuo, K. Adv. Synth. Catal. 2014, 356, 2459–2464.
(h) Fernandes, S.; Bhat, S. V. Synthesis 2014, 44, 2892–2898. (i) Yuan, W.; Wei, Y.; Shi, M.
Tetrahedron 2013, 67, 7139–7142. (j) Dengiz, C.; Caliskan, R.; Balci, M. Tetrahedron Lett.
2012, 53, 550–552. (k) Sudemen, M. B.; Zengin, M.; Genc, H.; Balci, M. Turk. J. Chem.
2011, 35, 1–11.
(4) Ceyhan, S.; Cetinkaya, Y.; Akdag, A.; Balci, M. Tetrahedron 2016, 72, 6815-6824.
(5) (a) Heiba, E. I.; Dessau, R. M. J. Am. Chem. Soc. 1974, 96, 7977–7981. (b) Heiba, E.
I.; Dessau, R. M. J. Am. Chem. Soc. 1972, 94, 2888–2889. (c) Heiba, E. I.; Dessau, R. M.; J.
Am. Chem. Soc. 1971, 93, 524–527.
(6) Fristad, W. E.; Peterson, J. R.; Ernst, A. B.; Urbi, G. B.; Tetrahedron 1986, 42, 3429–
3442. (b) ) Fristad, W. E.; Peterson, J. R. J. Org. Chem. 1985, 50, 10–18.
(7) (a) Ali, M. F.; Caliskan, R.; Sahin, E.; Balci, M. Tetrahedron 2009, 65, 1430–1437.
(b) Caliskan, R.; Ali, M. F.; Sahin, E.; Watson, W. H.; Balci, M. J. Org. Chem. 2007, 72,
3353–3359; (c) Caliskan, R.; Pekel, T.; Watson, W. H.; Balci, M. Tetrahedron Lett. 2005, 46,
6227–6230.
(8) (a) Whitesides ; G. M.; San Flippo, J. Jr. J. Am. Chem. Soc. 1970, 92, 6611–6624. (b)
Davies, D. I.; Cristol, S. J. Adv. Free-Radical Chem. 1965, 1, 156–157.
(9) (a) Kazaz, C.; Dastan, A.; Balci, M. Mag. Reson. Chem. 2005, 43, 75–81. (b) Stanley,
J. C.; Nachtigal, G. W. J. Org. Chem. 1967, 32, 3738–3743.
(10) Ziegler, G. R. J. Am. Chem. Soc. 1969, 91, 446–449.
(11) For the formation of a cyclopropane ring during Mn(OAc)3 oxidation see: (a) Snider,
B. B.; Che, Q. Tetrahedron 2002, 58, 7821–7827. (b) Oumar-Mahamat, H.; Moustrou, C.;
Surzur, J. M.; Bertrand, M. P. J. Org. Chem. 1989, 54, 5684–5688.
(12) (a) Logan, A. W. J.; Parker, J. S.; Hallside, M. S. Burton, J. W. Org. Lett. 2012, 14,
2940–2943. (b) Maemura, Y.; Tanoue, Y.; Nishino, H. Heterocycles 2012, 85, 2491–2503. (c)
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Johnson, A. E.; Zhang, S.; Chen, J.; Perchyonok, V. T. Curr. Org. Chem. 2009, 17, 1746–
1750.
(13) For the global electrophilicity/nucleophilicity scale of radicals see: De
Vleeschouwer, F.; Van Speybroeck, V.; Waroquier, M.; Geerlings, P.; De Proft, F. Org. Lett.
2007, 9, 2721–2724.
(14) Mohite, A. R; Bhat, R. G. Org. Lett. 2013, 15, 4564–4567.
(15) Rigaku/MSC, Inc., 9009 new Trails Drive, The Woodlands, TX 77381.
(16) Sheldrick, G.M. (1997)SHELXS-97 and SHELXL-97, Program for Crystal Structure
Solution and Refinement, University of Göttingen, Germany.
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