Ac2O-Mediated Dearylacetylative Dimerization of 2-Arylacetyl-1-naphthols: Synthesis of Naphtho[1,2-b]furan-3-ones

Article abstract of DOI:10.1021/acs.joc.9b03298

A novel and efficient route for the synthesis of 2-Aryl-2-naphthyl naphtho[1,2-b]furan-3-ones is described via NaH/Ac₂O-mediated dearylacetylative dimerization of 2-Arylacetyl-1-naphthols in refluxing THF under open-flask conditions. A plausibl

Full text of DOI:10.1021/acs.joc.9b03298

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Article
Ac2O-Mediated Dearylacetylative Dimerization of 2-
Arylacetyl-1-naphthols. Synthesis of Naphtho[1,2-b]furan-3-ones
Meng-Yang Chang, Kuan-Ting Chen, Yu-Ting Hsiao, and Shin-Mei Chen
J. Org. Chem., Just Accepted Manuscript • DOI: 10.1021/acs.joc.9b03298 • Publication Date (Web): 16 Jan 2020
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Ac2O-Mediated Dearylacetylative Dimerization of 2-Arylacetyl-1-
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naphthols. Synthesis of Naphtho[1,2-b]furan-3-ones
Meng-Yang Chang,*a,b Kuan-Ting Chen,a Yu-Ting Hsiaoa and Shin-Mei Chena
aDepartment of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung 807, Taiwan bDepartment of
Medical Research, Kaohsiung Medical University Hospital, Kaohsiung 807, Taiwan
*Email: mychang@kmu.edu.tw
Supporting Information Placeholder
OAc
OAc
O
Ar
Ar
Ar
O
O
1
OH
2
O
h, I
NaH, Ac O
2
2
O
o
EtOAc, 25
C
THF, reflux
ABSTRACT: A novel and efficient route for the synthesis of 2-aryl-2-naphthyl naphtho[1,2-b]furan-3-ones is described via
NaH/Ac2O-mediated dearylacetylative dimerization of 2-arylacetyl-1-naphthols in refluxing THF under open-flask conditions. A
plausible mechanism is also proposed and discussed. Various reaction conditions are investigated for one-pot transformation.
Introduction
demonstrated that a catalyst-free reaction of isatin, β-naphthol,
and 1,3-dicarbonyl species produced spiro-conjugated dihy-
droquinoline-naphthofuranone.4a Khosropour et al. investigat-
ed a pseudo-four-component synthesis of naphtho[2,1-b]furan-
2-one via a H4[Si(W3O10)4]-immobilized SiO2@Fe3O4 nano-
catalyst promoted domino conjugation of arylaldehyde, hippu-
ric acid, β-naphthol, and acetic anhydride.4b The Ahmed group
explored the idea that a Cu(OAc)2-promoted a 2-oxo driven
reaction of arylglyoxal, β-naphthol and pyrrolidine produced
naphtho[2,1-b]furan-1-one under microwave-assisted condi-
tions.5a Piersanti et al. reported a diphenyl phosphate-mediated
cascade synthesis of naphtho[2,1-b]furan-1-one via an aza-
Friedel-Crafts-lactonization reaction sequence of β-naphthol
with 2-acetamidoacrylate.5b The Miura team developed a
Pd(PPh3)4-catalyzed elegant synthesis of simple naphtho[1,2-
b]furan-2-one via three component cross-coupling of α-
naphthol (Y = H) and aldehydes in the presence of CO.6
Naphthofuranone derivatives are valuable core structures
for heterocyclic molecules containing bioactive properties as a
result of their broad presence in various natural sources or
secondary metabolites.1-3 For the reported synthetic routes of
diversified angular4-6 or linear7 tricyclic naphtho-fused
furanones, bicyclic α-naphthol and β-naphthol are often cho-
sen as the common building blocks to set up the furanone-
containing framework on the basis of an intermolecular formal
(3+2) benzannulation.
Scheme 1. Synthetic Routes of Naphtho-fused Furanones
O
O
C
Ar
HN
O
O
O
O
N
H
Ar
,
O
Ac O
2
BzHN
O
OH
OH
H
OSO Na
3
H [Si(W O ) ]
12 25
4
3 10 4
O
O
O
BzHN
OH
(Lu work)
HO
(Khosropour work)
O
Among the synthetic variations toward different methods,
the construction of carbon-carbon and carbon-oxygen bonds
(C-C and C-O, green marks) has served as the major synthetic
route. As observed in the above reports, the development of a
facile synthetic route to access these functionalized naphtho-
fused furanones has attracted significant attention. On the ba-
sis of the reports on intermolecular formal (3+2) benzannula-
tion, we herein report a novel intramolecular benzannulation
route for the synthesis of angular naphtho[1,2-b]furan-3-one
via Ac2O/NaH-mediated dearylacetylative dimerization of 2-
arylacetyl-1-naphthols in refluxing THF under open-flask
conditions. Various synthetic approaches using different types
of reductive dimerization have been studied.8 However, to the
best of our knowledge, no direct synthetic route for the for-
O
O
O
O
Ar
AcHN
O
Ar
AcHN
O
OMe
Cu(OAc)
2
pyrrolidine
W
(PhO) PO H
2
2
(Piersanti work)
(Ahmed work)
O
O
O
OAc
OAc
Y = H
O
Y =
Ar
Ar
YO
,
CO
O
1) h, I , EtOAc
2
O
Pd(PPh )
3
2) NaH, Ac O
2
4
(Miura work)
(this work)
As shown in Scheme 1, for the involvement of anionic sur-
factant (10 wt% sodium dodecyl sulfate/H2O), Lu et al.
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mation of naphtho[1,2-b]furan-3-one with a geminal 2,2-diaryl
group has been previously reported.
However, no reaction was observed for TFAA-mediated es-
terification of 4-nitro-1-naphthol (1f) with 2a. A possible ex-
planation is that the push-pull conjugated system on 1f de-
creased the nucleophilic ability such that no desired ester
product 3r was generated. With the amounts of 4a-4q on hand,
4a (R = H, Ar = Ph) was chosen as the model substrate to ex-
amine the dearylacetylative dimerization. The initial study
commenced with the treatment of 4a (0.5 mmol), NaH (2
equiv), and Ac2O (2 equiv) in THF (20 mL) at 25 °C for 5 h
under an open-flask condition. However, no desired 5a was
detected, and 4a was recovered at an 87% yield. By elongating
the time from 5 h to 10 or 20 h, 5a was still not observed.
With these results in mind, the reflux temperature was exam-
ined next, as shown in Table 1. Controlling the amounts of
NaH and Ac2O at 2 equivalents, the reflux temperature (25 
67 °C) produced 5a at a low yield (10%) for 20 h (entry 1).
Increasing the equivalents for the combination of NaH/Ac2O
(2/2  3/3  4/4  5/5  6/6), the isolated yields of 5a im-
proved from 10% to 34%, 59%, 68%, and 74%, respectively
(entries 2-5). Based on this result, 6/6 was determined to be a
reasonable equivalent ratio of NaH/Ac2O for increasing the
yield of 5a.
Results and Discussion
For the synthesis of 2,2-diaryl naphtho[1,2-b]furan-3-one 5
via Ac2O-mediated dearylacetylative dimerization, 2-
arylacetyl-1-naphthols 4a-4q were prepared by a two-step
route, as shown in Scheme 2, including (1) trifluoroacetic an-
hydride (TFAA)-mediated esterification of commercially
available α-naphthols 1a-1e (R = a, H; b, 5-MeO; c, 4-MeO; d,
4-Cl; e, 5-HO) with different arylacetic acids 2a-2l (Ar = a, Ph;
b, 3,4-(MeO)2C6H3; c, 4-FC6H4; d, 4-MeC6H4; e, 4-PhC6H4; f,
3,4-CH2O2C6H3; g, 2-thienyl; h, 4-BrC6H4; i, 3,5-F2C6H3; j, 4-
CF3C6H4; k, 1-naphthyl; l, 2-CF3C6H4; m, 2-MeOC6H4) in the
presence of H3PO4 at 25 °C, and (2) iodine-catalyzed Fries
rearrangement of the corresponding 3a-3q at room tempera-
ture (25 °C) by photolytic irradiation (λ = 2540 Å). The two-
step route produced 4a-4q with good to excellent yields under
mild conditions. The molecular structures of 4e and 4h were
determined by single-crystal X-ray crystallography.9
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12
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Scheme 2. Preparation of 2-Arylacetyl-1-naphthols 4
O
O
Ar
Ar
O
OH
O
1
OH
2
Furthermore, modifying the relative amounts of the combi-
nation to 4/6, a higher yield (78%) is achieved (entry 6). Based
on these results, 4 equivalents of NaH and 6 equivalents of
Ac2O were found to increase the yield of 5a. Different bases
were then examined; however, no improvements in the yield
of 5a were observed after changing NaH to tBuOK, DBU, or
Et3N. In entry 7, tBuOK afforded a complex mixture. DBU
produced 5a at a 35% yield (entry 8). Interestingly, no reaction
was observed for the addition of Et3N (entry 9). Compared to
the role of the three bases, different basicity and nucleophilc
ability provided three types of results. By adjusting the anhy-
dride from Ac2O to benzoyl anhydride (Bz2O), attempts to
afford the desired 5a failed due to a bulkier phenyl substituent
result (entry 10). Extending the reaction time (20  30 and 40
h), the yields of 5a fell to 62% and 37%, respectively (entries
11-12). Solvent screening was performed next in which reflux-
ing in DME (an acyclic ether) and dioxane (a cyclic ether)
provided 5a at 51% and 50% yields, respectively (entries 13-
14), indicating that the solvent with the higher boiling point
decreased the yield of 5a. The next step investigated the effect
of reaction concentration. By diminishing the solvent volume
from 20 to 10 mL, the yield (48%) of 5a decreased as a result
of the concentrated solvent system complicating the reaction
(entry 15). However, a diluted solution (30 mL of THF) pro-
vided a 72% yield of 5a, and the yield was maintained (entry
16). Under the oxygen atmosphere condition, the obtained
yield (76%) of 5a was similar to air atmosphere (entry 17). For
the approximate yields of 5a in entries 6 (78%, for air) and 17
(75%, for O2), the air atmosphere with an appropriate amount
of molecular oxygen was expected to be sufficient to initiate
the reaction to produce 5a. Compared to air, an oxygen atmos-
phere could not enhance the yield of 5a due to excess molecu-
lar oxygen inhibiting the generation of 5a. NaH (4
equiv)/Ac2O (6 equiv) in refluxing THF (20 mL) for 20 h was
thus concluded to be the optimal conditions for the dearyla-
cetylative dimerization ring-closure procedure under open-
vessel conditions. The expeditious synthetic route sets up the
naphtho[1,2-b]furan-3-one skeleton, including the formation
of the C-O and the C-C bonds via a formal (3+2) benzannula-
Ar
2
h, I
2
HO
o
H PO , TFAA
3
4
EtOAc, 25 C
o
MeCN, 25
C
R
R
R
5
4
1
3
4
Table 1. Reaction Conditionsa
OAc
OAc
Ph
base
anhydride
Ph
O
OH
2
O
O
reflux
condition
4a
5a (CCDC 1894548)
base
anhydride time solvent
5a
(%)b
10
entry
(equiv)
(equiv)
(h)
20
20
20
20
20
20
20
20
20
20
30
40
20
20
20
20
20
(mL)
1
2
3
4
5
6
7
8
9
NaH (2)
NaH (3)
NaH (4)
NaH (5)
NaH (6)
NaH (4)
Ac2O (2)
Ac2O (3)
Ac2O (4)
Ac2O (5)
Ac2O (6)
Ac2O (6)
THF (20)
THF (20)
THF (20)
THF (20)
THF (20)
THF (20)
THF (20)
THF (20)
THF (20)
THF (20)
THF (20)
THF (20)
DME (20)
34
59
68
74
78
c
tBuOK (4) Ac2O (6)
─
DBU (4)
Et3N (4)
Ac2O (6)
Ac2O (6)
Bz2O (6)
Ac2O (6)
Ac2O (6)
Ac2O (6)
Ac2O (6)
Ac2O (6)
Ac2O (6)
Ac2O (6)
35
d
─
d
10 NaH (4)
11 NaH (4)
12 NaH (4)
13 NaH (4)
14 NaH (4)
15 NaH (4)
16 NaH (4)
17 NaH (4)
─
62
37
51
dioxane (20) 50
THF (10)
THF (30)
THF (20)
48
72
76e
aReactions were run on a 0.5 mmol scale with 4a, base (1-6
equiv), anhydride (1-6 equiv), reflux temp, open-flask.
bIsolated yields. cComplex unknown mixture. dNo reaction. eO2
atmosphere.
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tion. A quaternary center at the 2-position carbon (pink) was
of 5g (entry 7). The molecular structure of 5g was determined
2
3
4
also established. The structure of 5a was determined by single-
by single-crystal X-ray crystallography.9 In entries 9-10 and 12,
the stronger electron-withdrawing aryl group (Ar = 3,5-F2C6H3,
4-CF3C6H4, 2-CF3C6H4) provided rather lower yields (74%,
70%, 70%) compared to the electron-donating oxygenated aryl
groups. When Ar was a bicyclic aromatic ring, 1-naphthyl
group produced 5k with a geminal 2,2-dinaphthyl group at a
75% yield (entry 11). For the formation of the α,α-dinaphthyl
group, the present route could construct a quaternary center at
the α-C2-carbon, resulting in a high steric hindrance.
crystal X-ray crystallography.9
5
6
7
8
On the basis of the abovementioned experimental results, a
plausible mechanism for the formation of 5a is illustrated in
Scheme 3. Initially, deprotonation of 4a with NaH yields
naphthoxide ion A. The involvement of molecular oxygen
generates B with an α-peroxy anion. After the acetylation of B
is treated with Ac2O, C with a peroxy acetate arm could be
formed along with acetate ion. Following the deprotonation of
C, the α-carbanion of C could attack another C-4 position on
the in situ C to lead to D, releasing an acylperoxy anion via
9
10
11
12
13
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60
Table 2. Synthesis of 5a-5l and 6m-6pa-b
intermolecular
nucleophilic
substitution.
This
self-
OAc
Me
Ar
dimerization process is a key step to conjugate two naphthyl
skeletons. By the removal of the proton at the C-4 position, the
dehydrogenative aromatization of D followed by acetylation
of the resulting 1-naphthoxide ion converts into E. The con-
struction of a furanone ring on F was then completed via in-
tramolecular annulation of the deprotonated E followed by the
removal of acetate ion. Furthermore, the release of peroxy
acetate anion attacks the carbonyl group to yield the Criegee
intermediate G. Through a Baeyer-Villiger type migration
process, H and acetate ion are formed. Finally, the correspond-
ing acetate ion-mediated transesterification of H with Ac2O
produces 5a and acetyl phenylacetate. Finally, after the hy-
drolysis of acetyl phenylacetate, phenylacetic acid (2a) and
HOAc could be formed spontaneously. However, the yield of
the resulting byproduct phenylacetic acid was similar to that of
the target compound 5a. For the overall reaction pathway,
these results provide evidence to demonstrate the plausible
mechanism.
Ar
O
Ar
O
OH
2
O
O
OAc
NaH, Ac O
2
O
THF, reflux
5
4
5
4
R
R
4a-4q
5a-5l
6m-6p
NaH
(for 4m)
- H O
2
(for 6m)
MeO
O
MeO
O
Me
Me
Me
Na
O
O
O
O
O
Ac O
2
O
O
I
II
III
entry
1
4, R =, Ar =
4a, H, Ph
5/6, (%)c
5a, 78
5b, 86
5c, 80
5d, 80
5e, 74
5f, 83
2
4b, H, 3,4-(MeO)2C6H3
4c, H, 4-FC6H4
3
4
4d, H, 4-MeC6H4
4e, H, 4-PhC6H4
4f, H, 3,4-CH2O2C6H3
4g, H, 2-thienyl
5
Scheme 3. Plausible Mechanism
6
Ph
O
7
5g, 74
5h, 80
5i, 74
O
Ph
O
Ph
O
O
O
O
8
4h, H, 4-BrC6H4
4i, H, 3,5-F2C6H3
4j, H, 4-CF3C6H4
4k, H, 1-naphthyl
4l, H, 2-CF3C6H4
4m, H, 2-MeOC6H4
4n, 5-MeO, Ph
OAc
4
NaH
Ac O
2
C
Ph
+
4a
9
O
O
O
OAc
O
O
O
2
10
11
12
13
14
15
16
17
5j, 70
O
O
A
B
OAc
5k, 75
5l, 70
C
H
Ac OAc
O
6m, 68
6n, 66
6o, 57
6p, 54
5q/6q, ─c
OAc
O
OAc
O
Ph
Ph
Ph
H
4
O
O
O
Ph
Ph
Ph
O
O
O
O
O
4o, 4-MeO, Ph
O
O
O
+
+
OAc
OAc
OAc
OAc
4p, 4-Cl, Ph
F
E
D
4q, 5-PhCH2C(=O), Ph
aReactions were run on a 0.5 mmol scale with 4a-4q, NaH (80
mg, 2.0 mmol), Ac2O (310 mg, 3.0 mmol), THF (20 mL),
reflux, open-flask. bIsolated yields. cComplex mixture.
OAc
O
OAc
OAc
OAc
Ph
Ph
Ph
Ac OAc
OAc
O
O
O
O
O
O
O
O
AcO
+
Ph
2a
+
HOAc
O
Ph
When 4m, with an o-methoxyphenyl group, was reacted
with the combination of NaH/Ac2O, 6m with a chromone
skeleton was isolated at a 68% yield, and no desired 5m was
generated (entry 13). Chromones are the key component of
naturally occurring oxygen-containing heterocyclic com-
pounds, which possess various biological activities.10 We be-
lieve that in situ formed intermediate I with a sodium-ion che-
lated cyclic ether (among carbonyl, methoxy and naphthoxide
ion) triggered the direct acetylation of I with Ac2O to give II.
By acetyl migration of II followed by dehydration of III, 6m
was achieved via a Perkin-type reaction procedure. From the
Ph
+ AcO
H
O
G
5a
To study the substrate scope and limitations of this ap-
proach, 4a-4l were reacted with a combination of NaH and
Ac2O in refluxing THF to afford diversified naphtho[1,2-
b]furan-3-one skeleton with a geminal 2,2-diaryl group, as
shown in Table 2 (entries 1-12). By changing the aryl (Ar)
group, the electron-neutral, electron-donating, and electron-
withdrawing aryl groups were found to be appropriate for gen-
erating 5a-5l in a range of 70%-86% yields. For the heterocy-
clic aryl ring, 2-thienyl group provided a modest yield (74%)
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above results, by controlling Ar as the Ph group, the R group
of 1-naphthol can be changed from H to 5-MeO, 4-MeO, and
4-Cl after examining the NaH/Ac2O-mediated reaction.
very stable such that the aromaticity property was not easy to
break.
Changing the core from 1-naphthol to 2-naphthol was fur-
5
6
7
8
Entries 14-16 unexpectedly showed that 5- or 4-methoxy-1-
naphthols 4n-4o and 4-chloro-1-naphthol 4p afforded 6n-6p
with the chromone skeleton at 66%, 57% and 54% yields,
respectively, via the Perkin-type reaction pathway, but no 5n-
5p with the naphtho[1,2-b]furan-3-one skeleton were observed
under the above reaction conditions. To determine why the
chromone skeleton is preferred, the simple 1-naphthol (R = H)
was substituted with 5-MeO, 4-MeO or 4-Cl groups, indicat-
ing that the electron density of the naphthyl ring could be en-
riched such that the acetylation of 1-naphthoxide ion with
Ac2O was favored over the oxygenation of 1-naphthoxide ion
(for intermediate B, in Scheme 3). Conversely, 4q (R = 5-
PhCH2C(=O), Ar = Ph), with an electron-withdrawing group,
was treated with the NaH/Ac2O combination, producing only a
complex unknown mixture (entry 17). Within the mixture, the
formation of 5q or 6q was not observed. Although the sub-
strate scope is limited, the present method is a novel route for
preparing the α-aryl-α-naphthyl naphtho[1,2-b]furan-3-one
skeleton.
ther examined. Under similar TFAA/H3PO4-mediated esterifi-
cation conditions, treatment of 2-naphthol (11) with 2a pro-
duced 12 in a 95% yield (Scheme 5). Next, Fries rearrange-
ment of 12 was examined. Weiss et al. has investigated related
studies.12 However, when 12 was treated with photolytic con-
ditions, no desired rearrangement products 13a and 13b could
be detected under the present photo-Fries conditions. Further-
more, AlCl3-mediated Fries rearrangement of 12 was exam-
ined next. However, only a complex and unidentified mixture
was observed.
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
Scheme 5. Rearrangement of 12
O
Ph
h, I
O
OH
O
O
OH
OH
O
2
Ph
2a
Ph
Ph
2
HO
+
o
H PO , TFAA
EtOAc, 25
C
3
4
o
MeCN, 25
C
11
12 (95%)
13a (ND)
13b (ND)
In summary, this research has developed a facile one-pot
route for the synthesis of 2-aryl-2-naphthyl naphtho[1,2-
b]furan-3-ones via the NaH/Ac2O-mediated dearylacetylative
dimerization of 2-arylacetyl-1-naphthols. Related plausible
mechanisms have also been proposed. The molecular struc-
tures of the key products were confirmed by X-ray crystallog-
raphy, and the uses of various reaction conditions were inves-
tigated for efficient transformation. Further investigations
regarding the synthetic application of substituted 1-naphthols
will be conducted and published in due course.
Scheme 4. Synthesis of 10a-10c
O
Me
O
Ar
Ar
O
Ar
O
OH
7
O
OH
O
3
Ar
2
AlCl
NaH, Ac O
2
3
HO
MeNO
o
H PO , TFAA
MeCN, 25
2
THF, reflux
3
4
o
C
25
C
2a, Ar = Ph
2c, Ar = 4-FC H
2e, Ar = 4-PhC H
2i, Ar = 3,5-F C H
2n, Ar = 2-NO C H
2g, Ar = 2-thienyl
8a (93%)
8b (96%)
8c (95%)
8d (94%)
8e (94%)
8f (90%)
9a (70%)
9b (64%)
9c (69%)
9d (70%)
9e (45%)
9f (ND)
10a (76%)
10b (80%)
10c (78%)
10d (ND)
10e (ND)
6
4
6
4
2
6 3
2
6 4
Experimental Section
As an extension of the one-pot annulation, changing the
core from 1-naphthol to phenol was investigated (Scheme 4).
TFAA/H3PO4-mediated treatment of phenol (7) with different
arylacetic acids 2a, 2c, 2e, 2i, 2n and 2g (Ar = a, Ph; c, 4-
FC6H4; e, 4-PhC6H4; i, 3,5-F2C6H3; n, 2-NO2C6H4; g, 2-thienyl)
provided 8a-8f in mild and high-yield (90%-96%) esterifica-
tion conditions. In the following step, by using the photo-Fries
rearrangement condition from 3 to 4, surprisingly, no reaction
was observed for the transformation from 8 to 9. After evalu-
ating several rearrangement conditions, AlCl3 was found to be
a better promoter for the Fries rearrangement of 8a-8f, but the
isolated yields of 9a-9e (45%-70%) were lower than the
abovementioned conditions. The molecular structure of 9d
was determined by single-crystal X-ray crystallography.9 Spe-
cifically, 9f produced a complex unknown mixture under the
AlCl3-mediated Fries reaction condition, likely because the
carbonyl group and sulfur atom of 8f could chelate with AlCl3
such that 9f was not easy to generate. When 9a-9e were treat-
ed with the combination of NaH/Ac2O, only 10a-10c with the
chromone skeleton were isolated (76%-80%). A possible ex-
planation for the two types of naphtho[1,2-b]furan-3-one and
chromone skeletons is that the aromaticity between 1-naphthol
and phenol with the 2-arylacetyl arm is the key factor in divid-
ing the NaH/Ac2O-mediated reaction pathways and affecting
the distributed tendency of the formed products. 1-Naphthyl
rings have less aromatic stability than phenyl rings such that
the more reactive naphthyl ring could react with molecular
oxygen to trigger the formation of intermediate B.11 Compared
to the 1-naphthyl ring, the phenyl ring with 6π electrons is
General. Commercially available reagents and solvents were
used without further purification. All reactions were carried by
standard procedures under an air atmosphere (an open-vessel
condition). All products in EtOAc and CH2Cl2 were dried with
anhydrous magnesium sulfate before concentration in vacuo
under reduced pressure. The heating mantle is used to provide
a stable heat source. Melting points (mp) were recorded with a
1
SMP3 melting apparatus. H NMR (400 MHz) and 13C{1H}
NMR (100 MHz) spectroscopic data were measured on a
Varian INOVA-400 spectrometer, respectively. Chemical shift
values (δ) are reported in ppm relative to CDCl3 as the internal
standards, and coupling contants (J values) are reported in
Hertz (Hz). High-resolution mass spectroscopic data (HRMS)
were measured with a double focusing mass spectrometer by
ESI using a hybrid ion-trap. X-ray single crystal structures
were determined with a diffractometer (CAD4, Kappa CCD).
For the starting substrates 1a-1f and 2a-2n, these materials
were purchased commercially and were used without further
purification.
General synthetic procedure of compounds 3a-3q is as
follows: Trifluoroacetic anhydride (TFAA, 230 mg, 1.1 mmol)
and phosphoric acid (H3PO4, 110 mg, 1.1 mmol) were added
to a solution of substituted arylacetic acids 2a-2m (for 3a-3p,
1.05 mmol, for 3q, 2.1 mmol) in MeCN (15 mL) at 25 oC. The
reaction mixture was stirred at 25 oC for 30 min. Substituted 1-
naphthols 1a-1e (1.0 mmol) in MeCN (5 mL) was added to the
o
reaction mixture at 25 C. The reaction mixture was stirred at
25 oC for 20 h. The solvent of reaction mixture was
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The Journal of Organic Chemistry
concentrated. The residue was diluted with water (10 mL) and
MHz, CDCl3): δ 7.86 (d, J = 8.0 Hz, 1H), 7.74 (d, J = 8.4 Hz,
2
the mixture was extracted with CH2Cl2 (3 x 20 mL). The
combined organic layers were washed with brine, dried,
filtered and evaporated to afford crude product under reduced
pressure. Purification on silica gel (hexanes/EtOAc = 10/1~1/1)
afforded compounds 3a-3q.
1H), 7.68-7.63 (m, 5H), 7.59-7.57 (m, 2H), 7.51-7.37 (m, 6H),
7.27 (dd, J = 0.8, 8.4 Hz, 1H), 4.08 (s, 2H); 13C{1H} NMR
(100 MHz, CDCl3): δ 169.9, 146.5, 140.7, 140.5, 134.6, 132.5,
129.9 (2x), 128.8 (2x), 127.9, 127.5 (2x), 127.4, 127.1 (2x),
126.7, 126.41, 126.39, 126.0, 125.3, 121.0, 118.0, 41.2.
3
4
5
6
7
8
9
Phenylacetic acid naphthalen-1-yl ester (3a). 3a was
synthesized according to general synthetic procedure from 1a
(144 mg, 1.0 mmol) and 2a (143 mg, 1.05 mmol). Yield =
96% (252 mg); Colorless oil; HRMS (ESI-TOF) m/z: [M +
Benzo[1,3]dioxol-5-ylacetic acid naphthalen-1-yl ester (3f).
3f was synthesized according to general synthetic procedure
from 1a (144 mg, 1.0 mmol) and 2f (189 mg, 1.05 mmol).
Yield = 90% (275 mg); White solid; mp = 106-108 oC
(recrystallized from hexanes and EtOAc); HRMS (ESI-TOF)
m/z: [M + H]+ calcd for C19H15O4 307.0970 found 307.0976;
1H NMR (400 MHz, CDCl3): δ 7.90-7.87 (m, 1H), 7.77-7.74
(m, 2H), 7.55-7.46 (m, 3H), 7.29 (dd, J = 0.8, 7.6 Hz, 1H),
7.03 (d, J = 2.0 Hz, 1H), 6.97 (dd, J = 1.6, 8.0 Hz, 1H), 6.89 (d,
J = 8.0, 1H), 6.00 (s, 2H), 3.96 (s, 2H); 13C{1H} NMR (100
MHz, CDCl3): δ 170.0, 147.9, 146.9, 146.4, 134.5, 127.9,
126.9, 126.6, 126.34, 126.30, 125.9, 125.2, 122.6, 120.9,
117.9, 109.8, 108.4, 101.0, 41.0.
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
H]+ calcd for C18H15O2 263.1072, found 263.1074; H NMR
(400 MHz, CDCl3): δ 7.89 (dd, J = 0.4, 8.0 Hz, 1H), 7.77 (d, J
= 8.4 Hz, 1H), 7.70 (dd, J = 0.4, 8.0 Hz, 1H), 7.57-7.39 (m,
8H), 7.30 (dd, J = 1.2, 7.6 Hz, 1H), 4.08 (s, 2H); 13C{1H}
NMR (100 MHz, CDCl3): δ 169.9, 146.5, 134.5, 133.5, 129.4
(2x), 128.8 (2x), 127.9, 127.4, 126.7, 126.33, 126.31, 126.0,
125.2, 120.9, 117.9, 41.5.
(3,4-Dimethoxyphenyl)acetic acid naphthalen-1-yl ester (3b).
3b was synthesized according to general synthetic procedure
from 1a (144 mg, 1.0 mmol) and 2b (206 mg, 1.05 mmol).
Yield = 93% (300 mg); Colorless oil; HRMS (ESI-TOF) m/z:
Thiophen-2-ylacetic acid naphthalen-1-yl ester (3g). 3g was
synthesized according to general synthetic procedure from 1a
(144 mg, 1.0 mmol) and 2g (149 mg, 1.05 mmol). Yield =
94% (252 mg); Colorless oil; HRMS (ESI-TOF) m/z: [M +
1
[M + H]+ calcd for C20H19O4 323.1283, found 323.1284; H
NMR (400 MHz, CDCl3): δ 7.85 (d, J = 8.0 Hz, 1H), 7.73 (d,
J = 8.4 Hz, 1H), 7.67 (d, J = 8.4 Hz, 1H), 7.51-7.42 (m, 3H),
7.25 (d, J = 7.6 Hz, 1H), 7.05-7.02 (m, 2H), 6.91 (d, J = 8.4
Hz, 1H), 3.97 (s, 2H), 3.92 (s, 3H), 3.91 (s, 3H); 13C{1H}
NMR (100 MHz, CDCl3): δ 170.1, 149.0, 148.3, 146.4, 134.5,
127.9, 126.6, 126.3 (2x), 125.9, 125.8, 125.2, 121.6, 120.9,
117.9, 112.3, 111.3, 55.82, 55.80, 41.0.
1
H]+ calcd for C16H13O2S 269.0636, found 269.0640; H NMR
(400 MHz, CDCl3): δ 7.90-7.88 (m, 1H), 7.80-7.76 (m, 2H),
7.55-7.46 (m, 3H), 7.33 (dd, J = 1.2, 5.2 Hz, 1H), 7.31 (dd, J =
1.2, 7.2 Hz, 1H), 7.18-7.17 (m, 1H), 7.08 (dd, J = 2.8, 5.2 Hz,
1H), 4.28 (d, J = 0.8 Hz, 2H); 13C{1H} NMR (100 MHz,
CDCl3): δ 168.8, 146.4, 134.6, 134.3, 127.9, 127.3, 127.0,
126.6, 126.5, 126.4, 126.1, 125.4, 125.3, 121.0, 117.9, 35.6.
(4-Fluorophenyl)acetic acid naphthalen-1-yl ester (3c). 3c
was synthesized according to general synthetic procedure from
1a (144 mg, 1.0 mmol) and 2c (162 mg, 1.05 mmol). Yield =
92% (258 mg); Colorless oil; HRMS (ESI-TOF) m/z: [M +
(4-Bromophenyl)acetic acid naphthalen-1-yl ester (3h). 3h
was synthesized according to general synthetic procedure from
1a (144 mg, 1.0 mmol) and 2h (225 mg, 1.05 mmol). Yield =
1
o
H]+ calcd for C18H14FO2 281.0978, found 281.0983; H NMR
95% (323 mg); White solid; mp = 93-95 C (recrystallized
(400 MHz, CDCl3): δ 7.86 (d, J = 8.0 Hz, 1H), 7.74 (d, J = 8.4
Hz, 1H), 7.62 (dd, J = 0.8, 8.4 Hz, 1H), 7.51-7.42 (m, 5H),
7.23 (dd, J = 0.8, 7.6 Hz, 1H), 7.12-7.08 (m, 2H), 4.00 (s, 2H);
13C{1H} NMR (100 MHz, CDCl3): δ 169.8, 162.3 (d, J =
244.8 Hz), 146.4, 134.6, 131.0 (d, J = 8.4 Hz, 2x), 129.2 (d, J
= 3.0 Hz), 128.0, 126.7, 126.5, 126.4, 126.1, 125.3, 120.8,
117.9, 115.7 (d, J = 21.2 Hz, 2x), 40.7.
from hexanes and EtOAc); HRMS (ESI-TOF) m/z: [M + H]+
calcd for C18H14BrO2 341.0177, found 341.0172; 1H NMR
(400 MHz, CDCl3): δ 7.94-7.92 (m, 1H), 7.82-7.80 (m, 2H),
7.63-7.51 (m, 5H), 7.39-7.36 (m, 3H), 3.99 (s, 2H); 13C{1H}
NMR (100 MHz, CDCl3): δ 169.1, 146.2, 134.3, 132.2, 131.6
(2x), 130.9 (2x), 127.8, 126.4, 126.3, 126.2, 125.9, 125.1,
121.2, 120.7, 117.7, 40.4.
p-Tolylacetic acid naphthalen-1-yl ester (3d). 3d was
synthesized according to general synthetic procedure from 1a
(144 mg, 1.0 mmol) and 2d (158 mg, 1.05 mmol). Yield =
(3,5-Difluorophenyl)acetic acid naphthalen-1-yl ester (3i). 3i
was synthesized according to general synthetic procedure from
1a (144 mg, 1.0 mmol) and 2i (181 mg, 1.05 mmol). Yield =
93% (277 mg); Colorless oil; HRMS (ESI-TOF) m/z: [M +
o
90% (249 mg); White solid; mp = 84-86 C (recrystallized
from hexanes and EtOAc); HRMS (ESI-TOF) m/z: [M + H]+
H]+ calcd for C18H13F2O2 299.0884, found 299.0890; H NMR
1
1
calcd for C19H17O2 277.1229, found 277.1236; H NMR (400
(400 MHz, CDCl3): δ 7.96-7.94 (m, 1H), 7.90-7.87 (m, 1H),
7.82 (d, J = 8.0 Hz, 1H), 7.62-7.56 (m, 2H), 7.53 (d, J = 8.0
Hz, 1H), 7.40 (d, J = 7.6 Hz, 1H), 7.12-7.08 (m, 2H), 6.97-
6.91 (tt, J = 2.4, 9.2 Hz, 1H), 3.98 (s, 2H); 13C{1H} NMR (100
MHz, CDCl3): δ 168.6, 162.9 (d, J = 247.1 Hz), 162.8 (d, J =
247.1 Hz), 146.2, 136.8 (t, J = 9.0 Hz), 134.4, 127.9, 126.39,
126.35, 126.3, 126.0, 125.1, 120.6, 117.8, 112.321 (d, J = 11.4
Hz), 112.317 (d, J = 25.8 Hz), 102.7 (t, J = 25.8 Hz), 40.3.
MHz, CDCl3): δ 7.86 (d, J = 8.0 Hz, 1H), 7.73 (d, J = 8.4 Hz,
1H), 7.66 (d, J = 8.0 Hz, 1H), 7.51-7.38 (m, 5H), 7.25-7.23 (m,
3H), 4.00 (s, 2H), 2.40 (s, 3H); 13C{1H} NMR (100 MHz,
CDCl3): δ 170.2, 146.5, 137.1, 134.6, 130.4, 129.5 (2x), 129.3
(2x), 127.9, 126.7, 126.4 (2x), 126.0, 125.3, 121.0, 118.0, 41.2,
21.1.
Biphenyl-4-ylacetic acid naphthalen-1-yl ester (3e). 3e was
synthesized according to general synthetic procedure from 1a
(144 mg, 1.0 mmol) and 2e (223 mg, 1.05 mmol). Yield =
(4-Trifluoromethylphenyl)acetic acid naphthalen-1-yl ester
(3j). 3j was synthesized according to general synthetic
procedure from 1a (144 mg, 1.0 mmol) and 2j (214 mg, 1.05
o
93% (314 mg); White solid; mp = 125-127 C (recrystallized
from hexanes and EtOAc); HRMS (ESI-TOF) m/z: [M + H]+
mmol). Yield = 94% (310 mg); White solid; mp = 90-92 C
o
1
calcd for C24H19O2 339.1385, found 339.1380; H NMR (400
(recrystallized from hexanes and EtOAc); HRMS (ESI-TOF)
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2
3
4
5
6
7
8
m/z: [M + H]+ calcd for C19H14F3O2 331.0946, found 331.0952;
Phenylacetic acid 4-methoxynaphthalen-1-yl ester (3o). 3o
1H NMR (400 MHz, CDCl3): δ 7.96-7.94 (m, 1H), 7.82 (d, J =
8.4 Hz, 2H), 7.76 (d, J = 8.0 Hz, 2H), 7.61-7.52 (m, 5H), 7.40
(d, J = 7.6 Hz, 1H), 4.08 (s, 2H); 13C{1H} NMR (100 MHz,
CDCl3): δ 169.0, 146.3, 137.4, 134.5, 129.7, 129.5 (q, J = 32.6
Hz), 127.9 (2x), 126.5, 126.4, 126.3, 126.0, 125.5 (d, J = 3.8
Hz, 2x), 124.2 (q, J = 270.3 Hz), 125.2, 120.7, 117.8, 40.7.
was synthesized according to general synthetic procedure from
1c (174 mg, 1.0 mmol) and 2a (143 mg, 1.05 mmol). Yield =
96% (280 mg); Colorless oil; HRMS (ESI-TOF) m/z: [M +
1
H]+ calcd for C19H17O3 293.1178, found 293.1183; H NMR
(400 MHz, CDCl3): δ 8.27 (dd, J = 1.6, 8.8 Hz, 1H), 7.57-7.36
(m, 8H), 7.15 (d, J = 8.4 Hz, 1H), 6.75 (d, J = 8.4 Hz, 1H),
4.02 (s, 2H), 3.99 (s, 3H); 13C{1H} NMR (100 MHz, CDCl3):
δ 170.3, 153.4, 139.8, 133.6, 129.4 (2x), 128.8 (2x), 127.40,
127.36, 126.9, 126.1, 125.6, 122.3, 120.7, 117.6, 102.7, 55.6,
41.5.
Naphthalen-1-ylacetic acid naphthalen-1-yl ester (3k). 3k
was synthesized according to general synthetic procedure from
1a (144 mg, 1.0 mmol) and 2k (195 mg, 1.05 mmol). Yield =
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
o
90% (281 mg); White solid; mp = 92-94 C (recrystallized
from hexanes and EtOAc); HRMS (ESI-TOF) m/z: [M + H]+
Phenylacetic acid 4-chloronaphthalen-1-yl ester (3p). 3p was
synthesized according to general synthetic procedure from 1d
(178 mg, 1.0 mmol) and 2a (143 mg, 1.05 mmol). Yield =
1
calcd for C22H17O2 313.1229, found 313.1235; H NMR (400
MHz, CDCl3): δ 8.33 (d, J = 8.8 Hz, 1H), 8.01 (d, J = 8.8 Hz,
1H), 7.95 (d, J = 8.4 Hz, 1H), 7.87 (d, J = 8.4 Hz, 1H), 7.75 (d,
J = 8.0 Hz, 1H), 7.71-7.57 (m, 5H), 7.52-7.45 (m, 2H), 7.39
(dt, J = 1.2, 8.4 Hz, 1H), 7.31 (dd, J = 0.8, 7.6 Hz, 1H), 4.54 (s,
2H); 13C{1H} NMR (100 MHz, CDCl3): δ 169.9, 146.4, 134.4,
133.8, 132.0, 130.0 (2x), 128.8, 128.34, 128.29, 127.8, 126.6,
126.22, 126.19, 125.9 (2x), 125.5, 125.2, 123.7, 120.9, 117.8,
39.4.
o
95% (281 mg); White solid; mp = 87-89 C (recrystallized
from hexanes and EtOAc); HRMS (ESI-TOF) m/z: [M + H]+
calcd for C18H14ClO2 297.0682, found 297.0689; 1H NMR
(400 MHz, CDCl3): δ 8.28 (dd, J = 1.2, 8.8 Hz, 1H), 7.66 (dd,
J = 0.8, 8.4 Hz, 1H), 7.61 (dt, J = 1.2, 8.4 Hz, 1H), 7.56 (d, J =
8.0 Hz, 1H), 7.53-7.38 (m, 6H), 7.20 (d, J = 8.0 Hz, 1H), 4.05
(s, 2H); 13C{1H} NMR (100 MHz, CDCl3): δ 169.7, 145.4,
133.2, 131.5, 129.4 (2x), 129.3, 128.8 (2x), 127.7, 127.5,
127.4, 127.1, 125.4, 124.7, 121.4, 118.0, 41.5.
(2-Trifluoromethylphenyl)acetic acid naphthalen-1-yl ester
(3l). 3l was synthesized according to general synthetic
procedure from 1a (144 mg, 1.0 mmol) and 2l (214 mg, 1.05
mmol). Yield = 95% (314 mg); White solid; mp = 154-155 oC
(recrystallized from hexanes and EtOAc); HRMS (ESI-TOF)
m/z: [M + H]+ calcd for C19H14F3O2 331.0946, found 331.0956;
1H NMR (400 MHz, CDCl3): δ 8.02 (d, J = 7.6 Hz, 1H), 7.96
(d, J = 8.4 Hz, 1H), 7.84 (d, J = 8.0 Hz, 1H), 7.83 (d, J = 8.4
Hz, 1H), 7.67-7.54 (m, 5H), 7.47-7.42 (m, 2H), 4.39 (s, 2H);
13C{1H} NMR (100 MHz, CDCl3): δ 169.0, 146.4, 134.5,
132.6, 131.9, 131.6 (d, J = 1.5 Hz), 128.7 (q, J = 30.3 Hz),
127.8, 127.5, 126.6, 126.32, 126.29, 125.93 (q, J = 6.9 Hz),
125.92, 125.1, 124.5 (q, J = 272.2 Hz), 120.8, 117.8, 38.1 (d, J
= 1.5 Hz).
Phenylacetic acid 5-phenylacetoxynaphthalen-1-yl ester (3q).
3q was synthesized according to general synthetic procedure
from 1e (160 mg, 1.0 mmol) and 2a (286 mg, 2.1 mmol).
Yield = 90% (357 mg); White solid; mp = 89-91 oC
(recrystallized from hexanes and EtOAc); HRMS (ESI-TOF)
m/z: [M + H]+ calcd for C26H21O4 397.1440, found 397.1448;
1H NMR (400 MHz, CDCl3): δ 7.50-7.38 (m, 14H), 7.26 (dd, J
= 0.8, 7.2 Hz, 2H), 4.02 (s, 4H); 13C{1H} NMR (100 MHz,
CDCl3): δ 169.7 (2x), 146.5 (2x), 133.3 (2x), 129.4 (4x), 128.8
(4x), 128.0 (2x), 127.5 (2x), 125.9 (2x), 119.1 (2x), 118.6 (2x),
41.5 (2x).
General synthetic procedure of compounds 4a-4q is as
follows: 3a-3q (1.0 mmol) and I2 (25 mg, 0.1 mmol) was
dissolved in EtOAc (30 mL) at 25 oC. Then, 1,2-epoxybutane
(140 mg, 2.0 mmol) was added to the reaction mixture and the
reaction mixture was irradiated under a nitrogen atmosphere
with a lamp (λ = 2540 Å), using a pyrex glass filter at 25 oC
for 50 h. The solvent was evaporated to afford crude product.
Purification on silica gel (hexanes/EtOAc = 4/1~2/1) afforded
compounds 4a-4q.
(2-Methoxyphenyl)acetic acid naphthalen-1-yl ester (3m).
3m was synthesized according to general synthetic procedure
from 1a (144 mg, 1.0 mmol) and 2m (174 mg, 1.05 mmol).
Yield = 90% (263 mg); White solid; mp = 81-83 oC
(recrystallized from hexanes and EtOAc); HRMS (ESI-TOF)
m/z: [M + H]+ calcd for C19H17O3 293.1178, found 293.1183;
1H NMR (400 MHz, CDCl3): δ 7.89-7.85 (m, 2H), 7.75 (d, J =
8.4 Hz, 1H), 7.54-7.49 (m, 2H), 7.47 (d, J = 7.6 Hz, 1H), 7.40-
7.24 (m, 2H), 7.30 (dd, J = 0.8, 7.6 Hz, 1H), 7.02 (dt, J = 0.8,
8.0 Hz, 1H), 6.98 (d, J = 8.4 Hz, 1H), 4.07 (s, 2H), 3.93 (s,
3H); 13C{1H} NMR (100 MHz, CDCl3): δ 170.2, 157.6, 146.7,
134.5, 131.1, 128.9, 127.8, 126.9, 126.3, 126.2, 125.8, 125.3,
122.6, 121.3, 120.6, 117.9, 110.4, 55.4, 36.4.
1-(1-Hydroxynaphthalen-2-yl)-2-phenylethanone (4a). 4a
was synthesized according to general synthetic procedure from
3a (262 mg, 1.0 mmol). Yield = 90% (236 mg); White solid;
o
mp = 101-103 C (recrystallized from hexanes and EtOAc);
HRMS (ESI-TOF) m/z: [M + H]+ calcd for C18H15O2 263.1072,
found 263.1077; 1H NMR (400 MHz, CDCl3): δ 14.00 (s, 1H),
8.46 (dd, J = 0.4, 8.4 Hz, 1H), 7.77 (d, J = 8.8 Hz, 1H), 7.75 (d,
J = 8.0 Hz, 1H), 7.63 (dt, J = 1.2, 8.0 Hz, 1H), 7.53 (dt, J = 1.2,
8.8 Hz, 1H), 7.39-7.26 (m, 6H), 4.38 (s, 2H); 13C{1H} NMR
(100 MHz, CDCl3): δ 203.6, 163.2, 137.3, 134.2, 130.2, 129.4
(2x), 128.8 (2x), 127.4, 127.1, 126.0, 125.3, 124.49, 124.46,
118.4, 112.6, 45.4.
Phenylacetic acid 5-methoxynaphthalen-1-yl ester (3n). 3n
was synthesized according to general synthetic procedure from
1b (174 mg, 1.0 mmol) and 2a (143 mg, 1.05 mmol). Yield =
95% (278 mg); Colorless oil; HRMS (ESI-TOF) m/z: [M +
1
H]+ calcd for C19H17O3 293.1178, found 293.1182; H NMR
(400 MHz, CDCl3): δ 8.12 (dt, J = 0.8, 8.4 Hz, 1H), 7.47-7.44
(m, 1H), 7.41-7.36 (m, 3H), 7.34-7.29 (m, 3H), 7.22-7.20 (m,
1H), 7.17 (dt, J = 0.8, 8.4 Hz, 1H), 6.77 (d, J = 8.0 Hz, 1H),
3.98 (s, 2H), 3.95 (s, 3H); 13C{1H} NMR (100 MHz, CDCl3):
δ 170.0, 155.5, 146.3, 133.5, 129.4 (2x), 128.8 (2x), 127.8,
127.4, 126.9, 126.5, 124.5, 120.2, 118.6, 113.1, 104.3, 55.6,
41.6.
2-(3,4-Dimethoxyphenyl)-1-(1-hydroxynaphthalen-2-
yl)ethanone (4b). 4b was synthesized according to general
synthetic procedure from 3b (322 mg, 1.0 mmol). Yield =
o
86% (277 mg); White solid; mp = 113-115 C (recrystallized
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The Journal of Organic Chemistry
from hexanes and EtOAc); HRMS (ESI-TOF) m/z: [M + H]+
hexanes and EtOAc); HRMS (ESI-TOF) m/z: [M + H]+ calcd
2
1
1
calcd for C20H19O4 323.1283, found 323.1286; H NMR (400
for C19H15O4 307.0970, found 307.0977; H NMR (400 MHz,
3
MHz, CDCl3): δ 14.00 (s, 1H), 8.46 (dd, J = 0.4, 8.4 Hz, 1H),
7.77 (d, J = 8.8 Hz, 1H), 7.73 (d, J = 8.0 Hz, 1H), 7.63 (dt, J =
1.2, 8.0 Hz, 1H), 7.53 (dt, J = 1.2, 8.8 Hz, 1H), 7.27 (d, J = 8.8
Hz, 1H), 6.86-6.83 (m, 3H), 4.31 (s, 2H), 3.88 (s, 3H), 3.86 (s,
3H); 13C{1H} NMR (100 MHz, CDCl3): δ 203.8, 163.2, 149.1,
148.2, 137.3, 130.2 (2x), 127.4, 126.5, 126.0, 125.3, 124.5
(2x), 121.6, 118.4, 112.5, 111.4, 55.9 (2x), 45.0.
CDCl3): δ 14.00 (s, 1H), 8.46 (d, J = 8.4 Hz, 1H), 7.75 (d, J =
8.0 Hz, 1H), 7.73 (d, J = 8.8 Hz, 1H), 7.63 (dt, J = 1.2, 8.0 Hz,
1H), 7.53 (dt, J = 1.2, 8.8 Hz, 1H), 7.26 (d, J = 8.8 Hz, 1H),
6.81-6.75 (m, 3H), 5.95 (s, 2H), 4.27 (s, 2H); 13C{1H} NMR
(100 MHz, CDCl3): δ 203.6, 163.2, 147.9, 146.7, 137.3, 130.2,
127.6, 127.4, 126.0, 125.3, 124.5, 124.4, 122.6, 118.4, 112.5,
109.8, 108.5, 101.1, 44.9.
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
2-(4-Fluorophenyl)-1-(1-hydroxynaphthalen-2-yl)ethanone
(4c). 4c was synthesized according to general synthetic
procedure from 3c (280 mg, 1.0 mmol). Yield = 88% (246 mg);
1-(1-Hydroxynaphthalen-2-yl)-2-thiophen-2-ylethanone (4g).
4g was synthesized according to general synthetic procedure
from 3g (268 mg, 1.0 mmol). Yield = 90% (241 mg); White
solid; mp = 113-115 oC (recrystallized from hexanes and
EtOAc); HRMS (ESI-TOF) m/z: [M + H]+ calcd for
o
White solid; mp = 104-106 C (recrystallized from hexanes
and EtOAc); HRMS (ESI-TOF) m/z: [M + H]+ calcd for
1
1
C18H14FO2 281.0978, found 281.0982; H NMR (400 MHz,
C16H13O2S 269.0636, found 269.0641; H NMR (400 MHz,
CDCl3): δ 13.95 (s, 1H), 8.47 (d, J = 8.4 Hz, 1H), 7.76 (d, J =
8.4 Hz, 1H), 7.72 (d, J = 8.8 Hz, 1H), 7.64 (t, J = 7.2 Hz, 1H),
7.54 (t, J = 7.2 Hz, 1H), 7.28 (d, J = 8.4 Hz, 1H), 7.27 (d, J =
8.8 Hz, 2H), 7.09-7.04 (m, 2H), 4.33 (s, 2H); 13C{1H} NMR
(100 MHz, CDCl3): δ 203.2, 163.2, 161.9 (d, J = 241.0 Hz),
137.3, 131.0 (d, J = 8.3 Hz, 2x), 130.3, 129.7 (d, J = 3.0 Hz),
127.4, 126.0, 125.2, 124.4, 124.2, 118.5, 115.6 (d, J = 21.2 Hz,
2x), 112.4, 44.3.
CDCl3): δ 13.82 (s, 1H), 8.43 (dd, J = 0.4, 8.4 Hz, 1H), 7.72 (d,
J = 8.4 Hz, 1H), 7.70 (d, J = 8.8 Hz, 1H), 7.60 (dt, J = 1.2, 8.4
Hz, 1H), 7.50 (dt, J = 1.2, 8.4 Hz, 1H), 7.25-7.22 (m, 2H),
6.98-6.95 (m, 2H), 4.51 (s, 2H); 13C{1H} NMR (100 MHz,
CDCl3): δ 201.7, 163.3, 137.4, 135.1, 130.3, 127.4, 127.1,
127.0, 126.0, 125.3, 125.2, 124.5, 124.2, 118.5, 112.1, 39.3.
2-(4-Bromophenyl)-1-(1-hydroxynaphthalen-2-yl)ethanone
(4h). 4h was synthesized according to general synthetic
procedure from 3h (340 mg, 1.0 mmol). Yield = 84% (286
mg); White solid; mp = 129-131 oC (recrystallized from
hexanes and EtOAc); HRMS (ESI-TOF) m/z: [M + H]+ calcd
for C18H14BrO2 341.0177, found 341.0182; 1H NMR (400
MHz, CDCl3): δ 13.90 (s, 1H), 8.46 (dd, J = 0.4, 8.4 Hz, 1H),
7.75 (d, J = 8.0 Hz, 1H), 7.69 (d, J = 8.8 Hz, 1H), 7.64 (dt, J =
1.2, 8.4 Hz, 1H), 7.53 (dt, J = 1.2, 8.0 Hz, 1H), 7.49 (d, J = 8.8
Hz, 2H), 7.26 (d, J = 9.2 Hz, 1H), 7.18 (d, J = 8.8 Hz, 2H),
4.30 (s, 2H); 13C{1H} NMR (100 MHz, CDCl3): δ 202.8,
163.2, 137.3, 133.0, 131.8 (2x), 131.2 (2x), 130.3, 127.4,
126.1, 125.2, 124.4, 124.1, 121.2, 118.5, 112.4, 44.6. Single-
crystal X-Ray diagram: crystal of compound 4h was grown by
slow diffusion of EtOAc into a solution of compound 4h in
CH2Cl2 to yield colorless prisms. The compound crystallizes
in the monoclinic crystal system, space group P 21/c, a =
16.3545(7) Å , b = 11.9821(5) Å , c = 7.3657(3) Å , V =
1420.53(10) Å 3, Z = 4, dcalcd = 1.595 g/cm3, F(000) = 688, 2θ
range 1.265 to 26.419o, R indices (all data) R1 = 0.0284, wR2
= 0.0632.
1-(1-Hydroxynaphthalen-2-yl)-2-p-tolylethanone (4d). 4d
was synthesized according to general synthetic procedure from
3d (276 mg, 1.0 mmol). Yield = 92% (254 mg); White solid;
mp = 89-91 oC (recrystallized from hexanes and EtOAc);
HRMS (ESI-TOF) m/z: [M + H]+ calcd for C19H17O2 277.1229,
found 277.1224; 1H NMR (400 MHz, CDCl3): δ 14.01 (s, 1H),
8.46 (dd, J = 1.2, 8.4 Hz, 1H), 7.77 (d, J = 8.8 Hz, 2H), 7.73 (d,
J = 8.0 Hz, 1H), 7.63 (dt, J = 1.2, 8.0 Hz, 1H), 7.53 (dt, J = 1.2,
8.0 Hz, 1H), 7.26 (d, J = 8.8 Hz, 1H), 7.21 (d, J = 8.8 Hz, 1H),
7.19 (d, J = 8.0 Hz, 2H), 4.33 (s, 2H), 2.34 (s, 3H); 13C{1H}
NMR (100 MHz, CDCl3): δ 163.2, 136.8, 131.1, 130.2, 129.5
(2x), 129.3 (2x), 129.0, 128.3, 127.4, 126.0, 124.54, 125.3,
124.46, 118.4, 112.6, 45.0, 21.1.
2-Biphenyl-4-yl-1-(1-hydroxynaphthalen-2-yl)ethanone (4e).
4e was synthesized according to general synthetic procedure
from 3e (338 mg, 1.0 mmol). Yield = 93% (314 mg); White
solid; mp = 162-164 oC (recrystallized from hexanes and
EtOAc); HRMS (ESI-TOF) m/z: [M + H]+ calcd for C24H19O2
1
339.1385, found 339.1389; H NMR (400 MHz, CDCl3): δ
14.03 (s, 1H), 8.49 (d, J = 8.4 Hz, 1H), 7.80 (d, J = 8.8 Hz,
1H), 7.77 (d, J = 8.0 Hz, 1H), 7.68-7.60 (m, 5H), 7.57-7.53 (m,
1H), 7.47-7.34 (m, 5H), 7.29 (d, J = 8.8 Hz, 1H), 4.42 (s, 2H);
13C{1H} NMR (100 MHz, CDCl3): δ 203.5, 163.2, 140.6,
140.1, 137.3, 133.1, 130.2, 129.9 (2x), 128.7 (2x), 127.5 (2x),
127.4, 127.3, 127.0 (2x), 126.0, 125.3, 124.5, 124.4, 118.5,
112.6, 45.0. Single-crystal X-Ray diagram: crystal of
compound 4e was grown by slow diffusion of EtOAc into a
solution of compound 4e in CH2Cl2 to yield colorless prisms.
The compound crystallizes in the monoclinic crystal system,
space group C2/c, a = 25.037(5) Å , b = 8.0888(15) Å , c =
19.202(3) Å , V = 3413.6(11) Å 3, Z = 8, dcalcd = 1.313 g/cm3,
F(000) = 1416, 2θ range 1.853 to 26.536o, R indices (all data)
R1 = 0.0536, wR2 = 0.1327.
2-(3,5-Difluorophenyl)-1-(1-hydroxynaphthalen-2-
yl)ethanone (4i). 4i was synthesized according to general
synthetic procedure from 3i (298 mg, 1.0 mmol). Yield = 84%
o
(250 mg); White solid; mp = 113-115 C (recrystallized from
hexanes and EtOAc); HRMS (ESI-TOF) m/z: [M + H]+ calcd
for C18H13F2O2 299.0884, found 299.0887; 1H NMR (400
MHz, CDCl3): δ 13.82 (s, 1H), 8.47 (dd, J = 0.4, 8.4 Hz, 1H),
7.76 (d, J = 8.4 Hz, 1H), 7.67 (d, J = 8.8 Hz, 1H), 7.65 (dt, J =
1.2, 8.4 Hz, 1H), 7.55 (dt, J = 1.2, 8.0 Hz, 1H), 7.29 (d, J = 8.8
Hz, 1H), 6.86-6.84 (m, 2H), 6.75 (dt, J = 2.0, 8.8 Hz, 1H),
4.34 (s, 2H); 13C{1H} NMR (100 MHz, CDCl3): δ 201.9,
163.1 (d, J = 247.1 Hz), 163.4, 163.0 (d, J = 247.2 Hz), 137.7
(t, J = 9.1 Hz), 137.4, 130.5, 127.4, 126.2, 125.3, 124.6, 123.9,
118.7, 112.571 (d, J = 25.0 Hz), 112.571 (d, J = 11.4 Hz),
112.3, 102.8 (t, J = 25.0 Hz), 44.7.
2-Benzo[1,3]dioxol-5-yl-1-(1-hydroxynaphthalen-2-
yl)ethanone (4f). 4f was synthesized according to general
synthetic procedure from 3f (306 mg, 1.0 mmol). Yield = 94%
1-(1-Hydroxynaphthalen-2-yl)-2-(4-
trifluoromethylphenyl)ethanone (4j). 4j was synthesized
according to general synthetic procedure from 3j (330 mg, 1.0
o
(288 mg); White solid; mp = 109-111 C (recrystallized from
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8
1
mmol). Yield = 89% (294 mg); White solid; mp = 150-152 oC
(recrystallized from hexanes and EtOAc); HRMS (ESI-TOF)
m/z: [M + H]+ calcd for C19H14F3O2 331.0946, found 331.0940;
1H NMR (400 MHz, CDCl3): δ 13.85 (s, 1H), 8.47 (dd, J = 0.4,
8.4 Hz, 1H), 7.77 (d, J = 8.0 Hz, 1H), 7.73 (d, J = 8.8 Hz, 1H),
7.65 (dt, J = 1.2, 8.0 Hz, 1H), 7.63 (d, J = 8.0 Hz, 2H), 7.54
(dt, J = 1.2, 8.0 Hz, 1H), 7.76 (d, J = 8.0 Hz, 2H), 7.29 (d, J =
8.8 Hz, 1H), 4.44 (s, 2H); 13C{1H} NMR (100 MHz, CDCl3): δ
202.5, 163.3, 138.2, 137.4, 130.4, 129.9 (2x), 129.0 (q, J =
32.8 Hz), 127.4, 126.2, 125.6 (q, J = 3.8 Hz, 2x), 125.3, 124.5,
124.0, 120.2 (q, J = 269.3 Hz), 118.7, 112.4, 44.9.
for C19H17O3 293.1178, found 293.1186; H NMR (400 MHz,
CDCl3): δ 13.86 (s, 1H), 8.03 (d, J = 8.8 Hz, 1H), 7.76 (d, J =
9.2 Hz, 1H), 7.68 (dd, J = 0.4, 8.8 Hz, 1H), 7.44 (t, J = 8.0 Hz,
1H), 7.38-7.26 (m, 5H), 6.99 (d, J = 7.6 Hz, 1H), 4.38 (s, 2H),
3.99 (s, 3H); 13C{1H} NMR (100 MHz, CDCl3): δ 203.8,
162.7, 155.0, 134.2, 129.5 (2x), 129.1, 128.7 (2x), 127.1,
126.3, 126.1, 123.7, 116.3, 113.1, 112.5, 108.3, 55.7, 45.4.
1-(1-Hydroxy-4-methoxynaphthalen-2-yl)-2-phenylethanone
(4o). 4o was synthesized according to general synthetic
procedure from 3o (292 mg, 1.0 mmol). Yield = 83% (242
mg); Colorless oil; HRMS (ESI-TOF) m/z: [M + H]+ calcd for
C19H17O3 293.1178, found 293.1174; 1H NMR (400 MHz,
CDCl3): δ 13.73 (s, 1H), 8.45 (d, J = 8.4 Hz, 1H), 8.17 (d, J =
8.4 Hz, 1H), 7.66 (dd, J = 1.2, 8.4 Hz, 1H), 7.57 (dt, J = 0.8,
7.2 Hz, 1H), 7.40-7.28 (m, 5H), 6.90 (s, 1H), 4.33 (s, 2H),
3.92 (s, 3H); 13C{1H} NMR (100 MHz, CDCl3): δ 203.0,
158.1, 147.3, 134.4, 130.2, 129.8, 129.3 (2x), 128.8 (2x),
127.1, 126.6, 126.0, 124.4, 121.8, 111.3, 100.5, 55.6, 45.9.
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
1-(1-Hydroxynaphthalen-2-yl)-2-naphthalen-1-ylethanone
(4k). 4k was synthesized according to general synthetic
procedure from 3k (312 mg, 1.0 mmol). Yield = 89% (278
mg); White solid; mp = 133-135 oC (recrystallized from
hexanes and EtOAc); HRMS (ESI-TOF) m/z: [M + H]+ calcd
1
for C22H17O2 313.1229, found 313.1234; H NMR (400 MHz,
CDCl3): δ 13.97 (s, 1H), 8.50 (d, J = 8.4 Hz, 1H), 7.94-7.85
(m, 3H), 7.86 (d, J = 8.8 Hz, 1H), 7.79 (d, J = 8.0 Hz, 1H),
7.66 (dt, J = 1.2, 8.4 Hz, 1H), 7.58-7.52 (m, 3H), 7.48 (t, J =
8.0 Hz, 1H), 7.41 (d, J = 6.4 Hz, 1H), 7.30 (d, J = 8.8 Hz, 1H),
4.82 (s, 2H); 13C{1H} NMR (100 MHz, CDCl3): δ 203.6,
163.0, 137.3, 133.8, 132.1, 130.9, 130.2, 128.9, 128.1, 128.0,
127.4, 126.4, 126.0, 125.8, 125.5, 125.3, 124.5, 124.2, 123.6,
118.5, 112.7, 42.7.
1-(4-Chloro-1-hydroxynaphthalen-2-yl)-2-phenylethanone
(4p). 4p was synthesized according to general synthetic
procedure from 3p (296 mg, 1.0 mmol). Yield = 86% (255
o
mg); White solid; mp = 84-86 C (recrystallized from hexanes
and EtOAc); HRMS (ESI-TOF) m/z: [M + H]+ calcd for
1
C18H14ClO2 297.0682, found 297.0689; H NMR (400 MHz,
CDCl3): δ 13.90 (s, 1H), 8.80 (dd, J = 1.2, 8.4 Hz, 1H), 8.17 (d,
J = 8.0 Hz, 1H), 7.87 (s, 1H), 7.77 (dd, J = 1.2, 8.4 Hz, 1H),
7.61 (dt, J = 0.8, 8.0 Hz, 1H), 7.40-7.36 (m, 2H), 7.32-7.29 (m,
3H), 4.35 (s, 2H); 13C{1H} NMR (100 MHz, CDCl3): δ 162.2,
134.3, 133.6, 131.2, 129.5 (2x), 128.9 (3x), 127.3, 126.8,
126.4, 124.9, 124.4, 124.0, 121.5, 112.6, 45.3.
1-(1-Hydroxynaphthalen-2-yl)-2-(2-trifluoromethylphenyl)-
ethanone (4l). 4l was synthesized according to general
synthetic procedure from 3l (330 mg, 1.0 mmol). Yield = 81%
o
(267 mg); White solid; mp = 135-137 C (recrystallized from
hexanes and EtOAc); HRMS (ESI-TOF) m/z: [M + H]+ calcd
for C19H14F3O2 331.0946, found 331.0953; 1H NMR (400
MHz, CDCl3): δ 13.7 (s, 1H), 8.47 (dd, J = 0.4, 8.4 Hz, 1H),
7.78 (d, J = 8.4 Hz, 1H), 7.74 (d, J = 9.2 Hz, 2H), 7.65 (dt, J =
1.2, 8.0 Hz, 1H), 7.57 (dt, J = 1.2, 8.0 Hz, 1H), 7.54 (dt, J =
1.6, 8.4 Hz, 1H), 7.45 (t, J = 8.0 Hz, 1H), 7.35 (d, J = 7.6 Hz,
1H), 7.34 (d, J = 8.8 Hz, 1H), 4.62 (s, 2H); 13C{1H} NMR
(100 MHz, CDCl3): δ 202.3, 162.9, 137.4, 132.7 (d, J = 1.5
Hz), 131.9, 130.3, 129.2 (q, J = 29.6 Hz), 127.5, 127.4, 127.1
(q, J = 271.3 Hz), 126.3 (q, J = 5.3 Hz), 126.1, 125.3, 124.5,
123.9, 123.0, 118.7, 112.5, 42.3 (d, J = 1.5 Hz).
Phenylacetic acid 5-hydroxy-6-phenylacetylnaphthalen-1-yl
ester (4q). 4q was synthesized according to general synthetic
procedure from 3q (396 mg, 1.0 mmol). Yield = 58% (230
mg); White solid; mp = 117-119 oC (recrystallized from
hexanes and EtOAc); HRMS (ESI-TOF) m/z: [M + H]+ calcd
1
for C26H21O4 397.1440, found 397.1448; H NMR (400 MHz,
CDCl3): δ 13.97 (s, 1H), 8.35 (dt, J = 1.2, 8.4 Hz, 1H), 7.69 (d,
J = 9.2 Hz, 1H), 7.51-7.29 (m, 12H), 7.03 (dd, J = 0.4, 9.2 Hz,
1H), 4.35 (s, 2H), 4.02 (s, 2H); 13C{1H} NMR (100 MHz,
CDCl3): δ 203.7, 169.8, 162.9, 146.2, 133.9, 133.3, 130.5,
129.4 (4x), 128.9 (2x), 128.8 (2x), 127.6, 127.2, 126.7, 125.6,
125.1, 122.6, 122.5, 112.8, 111.5, 45.4, 41.5.
1-(1-Hydroxynaphthalen-2-yl)-2-(2-methoxyphenyl)ethanone
(4m). 4m was synthesized according to general synthetic
procedure from 3m (292 mg, 1.0 mmol). Yield = 86% (251
mg); White solid; mp = 131-133 oC (recrystallized from
hexanes and EtOAc); HRMS (ESI-TOF) m/z: [M + H]+ calcd
General synthetic procedure of compounds 5a-5l and 6m-6p
is as follows: NaH (60% in oil, 80 mg, 2.0 mmol) was added
to a solution of 4a-4p (0.5 mmol) in dry THF (15 mL) at 25 oC.
The reaction mixture was stirred at 25 C for 10 min. Ac2O
(310 mg, 3.0 mmol) in dry THF (5 mL) was added to the
1
for C19H17O3 293.1178, found 293.1183; H NMR (400 MHz,
o
CDCl3): δ 14.00 (s, 1H), 8.47 (dd, J = 0.4, 8.4 Hz, 1H), 7.85 (d,
J = 8.8 Hz, 1H), 7.76 (d, J = 8.0 Hz, 1H), 7.63 (dt, J = 1.6, 8.4
Hz, 1H), 7.53 (dt, J = 1.2, 8.4 Hz, 1H), 7.31 (dt, J = 1.6, 8.0
Hz, 1H), 7.28 (d, J = 8.8 Hz, 1H), 7.23 (dd, J = 1.6, 7.6 Hz,
1H), 6.97 (dt, J = 1.3, 8.8 Hz, 1H), 6.94 (dd, J = 0.4, 8.8 Hz,
1H), 4.39 (s, 2H), 3.82 (s, 3H); 13C{1H} NMR (100 MHz,
CDCl3): δ 204.1, 162.7, 157.2, 137.3, 131.0, 130.0, 128.7,
127.3, 125.8, 125.3, 124.6, 124.4, 123.1, 120.7, 118.2, 112.9,
110.6, 55.4, 39.8.
o
reaction mixture at 25 C. The reaction mixture was stirred at
reflux (67 C) for 20 h. The solvent of reaction mixture was
o
concentrated. The residue was diluted with water (10 mL) and
the mixture was extracted with CH2Cl2 (3 x 20 mL). The
combined organic layers were washed with brine, dried,
filtered and evaporated to afford crude product under reduced
pressure. Purification on silica gel (hexanes/EtOAc = 10/1~1/1)
afforded compounds 5a-5l and 6m-6p.
1-(1-Hydroxy-5-methoxynaphthalen-2-yl)-2-phenylethanone
(4n). 4n was synthesized according to general synthetic
procedure from 3n (292 mg, 1.0 mmol). Yield = 84% (245
mg); White solid; mp = 116-118 oC (recrystallized from
hexanes and EtOAc); HRMS (ESI-TOF) m/z: [M + H]+ calcd
Acetic
acid
2-acetoxy-4-(3-oxo-2-phenyl-2,3-
dihydronaphtho[1,2-b]furan-2-yl)naphthalen-1-yl ester (5a).
5a was synthesized according to general synthetic procedure
from 4a (131 mg, 0.5 mmol). Yield = 78% (98 mg); White
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solid; mp = 164-166 oC (recrystallized from hexanes and
EtOAc); HRMS (ESI-TOF) m/z: [M + H]+ calcd for C33H25O6
2
3
4
EtOAc); HRMS (ESI-TOF) m/z: [M + H]+ calcd for C32H23O6
503.1495, found 503.1498; H NMR (400 MHz, CDCl3): δ
517.1606, found 517.1613; H NMR (400 MHz, CDCl3): δ
1
1
8.34 (d, J = 7.6 Hz, 1H), 8.31 (d, J = 7.6 Hz, 1H), 7.90 (d, J =
8.4 Hz, 1H), 7.86 (dd, J = 0.4, 8.4 Hz, 1H), 7.83 (s, 1H), 7.72
(dt, J = 1.6, 8.4 Hz, 1H), 7.62 (d, J = 8.8 Hz, 1H), 7.60 (dt, J =
0.8, 8.0 Hz, 1H), 7.51 (d, J = 8.0 Hz, 1H), 7.49 (dd, J = 1.2,
8.4 Hz, 1H), 7.42 (dt, J = 1.2, 8.4 Hz, 1H), 7.26 (d, J = 8.0 Hz,
2H), 7.09 (d, J = 8.0 Hz, 2H), 2.45 (s, 3H), 2.32 (s, 3H), 2.29
(s, 3H); 13C{1H} NMR (100 MHz, CDCl3): δ 198.1, 172.1,
168.2, 167.9, 139.1, 138.3, 138.1, 137.7, 135.0, 131.5, 131.1,
131.0, 129.6 (2x), 129.2, 128.5, 127.7, 126.8, 126.7, 126.2,
125.4 (2x), 123.2, 122.6, 122.5, 121.7, 121.4, 119.6, 114.1,
94.3, 21.1, 20.7, 20.5.
8.34 (d, J = 8.4 Hz, 1H), 8.30 (d, J = 8.8 Hz, 1H), 7.91 (d, J =
8.0 Hz, 1H), 7.87 (d, J = 8.4 Hz, 1H), 7.85 (s, 1H), 7.73 (dt, J
= 1.2, 8.0 Hz, 1H), 7.63 (d, J = 8.8 Hz, 1H), 7.61 (t, J = 8.0 Hz,
1H), 7.53-7.48 (m, 2H), 7.43-7.38 (m, 3H), 7.33-7.28 (m, 3H),
2.45 (s, 3H), 2.33 (s, 3H); 13C{1H} NMR (100 MHz, CDCl3):
δ 197.9, 172.1, 168.2, 167.9, 139.1, 138.2, 137.9, 137.7, 131.4,
131.1, 131.0, 129.2, 128.9 (2x), 128.5, 128.4, 127.6, 126.9,
126.7, 126.2, 125.5 (2x), 123.3, 122.60, 122.57, 121.8, 121.4,
119.6, 114.0, 94.3, 20.7, 20.5. Single-crystal X-Ray diagram:
crystal of compound 5a was grown by slow diffusion of
EtOAc into a solution of compound 5a in CH2Cl2 to yield
colorless prisms. The compound crystallizes in the triclinic
crystal system, space group P -1, a = 8.1280(4) Å , b =
10.6123(6) Å , c = 14.7375(8) Å , V = 1210.15(11) Å 3, Z = 2,
dcalcd = 1.379 g/cm3, F(000) = 524, 2θ range 1.408 to 26.527o,
R indices (all data) R1 = 0.0577, wR2 = 0.1079.
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36
37
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43
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49
50
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55
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Acetic
acid
2-acetoxy-4-(2-biphenyl-4-yl-3-oxo-2,3-
dihydronaphtho[1,2-b]furan-2-yl)naphthalen-1-yl ester (5e).
5e was synthesized according to general synthetic procedure
from 4e (169 mg, 0.5 mmol). Yield = 74% (107 mg); White
solid; mp = 236-238 oC (recrystallized from hexanes and
EtOAc); HRMS (ESI-TOF) m/z: [M + H]+ calcd for C38H27O6
1
Acetic acid 2-acetoxy-4-[2-(3,4-dimethoxyphenyl)-3-oxo-2,3-
dihydronaphtho[1,2-b]furan-2-yl]naphthalen-1-yl ester (5b).
5b was synthesized according to general synthetic procedure
from 4b (161 mg, 0.5 mmol). Yield = 86% (121 mg); White
solid; mp = > 250 oC (recrystallized from hexanes and EtOAc);
HRMS (ESI-TOF) m/z: [M + H]+ calcd for C34H27O8 563.1706,
579.1808, found 579.1811; H NMR (400 MHz, CDCl3): δ
8.36 (d, J = 8.4 Hz, 1H), 8.35 (d, J = 8.4 Hz, 1H), 7.92 (d, J =
8.0 Hz, 1H), 7.88 (d, J = 8.4 Hz, 1H), 7.87 (s, 1H), 7.75 (dt, J
= 1.2, 8.0 Hz, 1H), 7.64 (d, J = 8.4 Hz, 1H), 7.62 (t, J = 8.0 Hz,
1H), 7.55-7.37 (m, 11H), 7.33-7.29 (m, 1H), 2.46 (s, 3H), 2.33
(s, 3H); 13C{1H} NMR (100 MHz, CDCl3): δ 197.9, 172.2,
168.2, 167.9, 141.3, 140.4, 139.1, 138.2, 137.8, 136.9, 131.3,
131.13, 131.09, 129.2, 128.7 (2x), 128.5, 127.6 (3x), 127.5,
127.1 (2x), 126.9, 126.7, 126.3, 125.9 (2x), 123.3, 122.64,
122.63, 121.8, 121.4, 119.6, 114.1, 94.2, 20.7, 20.5.
1
found 563.1708; H NMR (400 MHz, CDCl3): δ 8.34 (d, J =
8.4 Hz, 1H), 8.30 (d, J = 8.8 Hz, 1H), 7.92 (d, J = 8.4 Hz, 1H),
7.87 (d, J = 8.4 Hz, 1H), 7.77 (s, 1H), 7.73 (dt, J = 1.2, 8.0 Hz,
1H), 7.63 (d, J = 8.4 Hz, 1H), 7.61 (dt, J = 0.8, 8.0 Hz, 1H),
7.53 (d, J = 8.8 Hz, 1H), 7.50 (dt, J = 1.2, 8.0 Hz, 1H), 7.42
(dt, J = 1.2, 8.0 Hz, 1H), 6.98 (dd, J = 2.0, 8.4 Hz, 1H), 6.87 (d,
J = 2.0 Hz, 1H), 6.78 (d, J = 8.8 Hz, 1H), 3.82 (s, 3H), 3.70 (s,
3H), 2.45 (s, 3H), 2.32 (s, 3H); 13C{1H} NMR (100 MHz,
CDCl3): δ 198.1, 171.9, 168.2, 167.9, 149.2 (2x), 139.1, 138.1,
137.7, 131.5, 131.1, 131.0, 130.2, 129.1, 128.5, 127.5, 126.9,
126.7, 126.2, 123.2, 122.7, 122.5, 121.7, 121.4, 119.7, 118.3,
114.2, 111.2, 109.0, 94.2, 56.0, 55.8, 20.7, 20.5.
Acetic acid 2-acetoxy-4-(2-benzo[1,3]dioxol-5-yl-3-oxo-2,3-
dihydronaphtho[1,2-b]furan-2-yl)naphthalen-1-yl ester (5f).
5f was synthesized according to general synthetic procedure
from 4f (153 mg, 0.5 mmol). Yield = 83% (113 mg); White
solid; mp = 215-217 oC (recrystallized from hexanes and
EtOAc); HRMS (ESI-TOF) m/z: [M + H]+ calcd for C33H23O8
1
547.1393, found 547.1398; H NMR (400 MHz, CDCl3): δ
8.35 (d, J = 8.8 Hz, 1H), 8.31 (d, J = 8.4 Hz, 1H), 7.91 (d, J =
8.0 Hz, 1H), 7.87 (d, J = 7.6 Hz, 1H), 7.79 (s, 1H), 7.73 (dt, J
= 1.2, 8.0 Hz, 1H), 7.62 (d, J = 8.4 Hz, 1H), 7.60 (dt, J = 0.8,
8.0 Hz, 1H), 7.53-7.50 (m, 2H), 7.45 (dt, J = 1.2, 8.0 Hz, 1H),
6.86 (dd, J = 2.0, 8.4 Hz, 1H), 6.84 (s, 1H), 6.72 (d, J = 7.6 Hz,
1H), 6.92 (d, J = 1.2 Hz, 1H), 6.89 (d, J = 1.2 Hz, 1H), 2.45 (s,
3H), 2.32 (s, 3H); 13C{1H} NMR (100 MHz, CDCl3): δ 197.9,
172.0, 168.2, 167.8, 148.2, 147.8, 139.1, 138.2, 137.7, 131.7,
131.3, 131.13, 131.06, 129.2, 128.5, 127.6, 126.9, 126.7,
126.2, 123.3, 122.6, 122.5, 121.8, 121.3, 119.6, 119.5, 114.0,
108.6, 106.2, 101.3, 94.1, 20.7, 20.5.
Acetic
acid
2-acetoxy-4-[2-(4-fluorophenyl)-3-oxo-2,3-
dihydronaphtho[1,2-b]furan-2-yl]naphthalen-1-yl ester (5c).
5c was synthesized according to general synthetic procedure
from 4c (140 mg, 0.5 mmol). Yield = 80% (104 mg); White
solid; mp = 232-234 oC (recrystallized from hexanes and
EtOAc); HRMS (ESI-TOF) m/z: [M + H]+ calcd for
1
C32H22FO6 521.1401, found 521.1406; H NMR (400 MHz,
CDCl3): δ 8.33 (d, J = 8.0 Hz, 1H), 8.27 (d, J = 8.4 Hz, 1H),
7.91 (d, J = 8.0 Hz, 1H), 7.89 (d, J = 8.4 Hz, 1H), 7.82 (s, 1H),
7.73 (dt, J = 1.2, 8.0 Hz, 1H), 7.63 (d, J = 8.8 Hz, 1H), 7.61
(dt, J = 1.2, 8.0 Hz, 1H), 7.53 (d, J = 8.4 Hz, 1H), 7.52 (dt, J =
1.2, 8.4 Hz, 1H), 7.44 (dt, J = 1.2, 8.4 Hz, 1H), 7.38-7.35 (m,
2H), 7.01-6.97 (m, 2H), 2.46 (s, 3H), 2.33 (s, 3H); 13C{1H}
NMR (100 MHz, CDCl3): δ 197.7, 172.1, 168.2, 167.8, 162.7
(d, J = 247.2 Hz), 139.1, 138.3, 137.7, 133.8 (d, J = 3.0 Hz),
131.14, 131.0, 129.3, 128.5, 127.5, 127.4 (2x), 127.0, 126.8,
126.3, 123.5, 122.6 (d, J = 10.6 Hz, 2x), 121.9, 121.3, 119.5
(2x), 115.9 (d, J = 21.2 Hz, 2x), 113.9, 93.8, 20.7, 20.5.
Acetic
acid
2-acetoxy-4-(3-oxo-2-thiophen-2-yl-2,3-
dihydronaphtho[1,2-b]furan-2-yl)naphthalen-1-yl ester (5g).
5g was synthesized according to general synthetic procedure
from 4g (134 mg, 0.5 mmol). Yield = 74% (94 mg); White
solid; mp = 217-219 oC (recrystallized from hexanes and
EtOAc); HRMS (ESI-TOF) m/z: [M + H]+ calcd for
1
C30H21O6S 509.1059, found 509.1054; H NMR (400 MHz,
CDCl3): δ 8.48 (d, J = 8.4 Hz, 1H), 8.32 (d, J = 8.4 Hz, 1H),
7.91-7.88 (m, 2H), 7.84 (s, 1H), 7.72 (dt, J = 1.2, 8.0 Hz, 1H),
7.65 (d, J = 8.8 Hz, 1H), 7.60 (dt, J = 1.2, 8.0 Hz, 1H), 7.55-
7.46 (m, 3H), 7.29 (dd, J = 1.2, 5.2 Hz, 1H), 7.01 (dd, J = 1.2,
3.6 Hz, 1H), 6.95 (dd, J = 3.6, 5.2 Hz, 1H), 2.45 (s, 3H), 2.32
(s, 3H); 13C{1H} NMR (100 MHz, CDCl3): δ 196.6, 171.6,
Acetic
acid
2-acetoxy-4-(3-oxo-2-p-tolyl-2,3-
dihydronaphtho[1,2-b]furan-2-yl)naphthalen-1-yl ester (5d).
5d was synthesized according to general synthetic procedure
from 4d (138 mg, 0.5 mmol). Yield = 80% (103 mg); White
solid; mp = 244-246 oC (recrystallized from hexanes and
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168.1, 167.8, 141.1, 139.1, 138.4, 137.7, 131.1 (2x), 131.0,
(2x), 126.9, 126.5, 125.9 (3x), 124.2 (q, J = 270.1 Hz), 123.7,
122.9, 122.5, 122.0, 121.3, 119.5, 113.8, 93.7, 20.7, 20.5.
129.1, 128.5, 127.4, 127.3, 126.93, 126.87, 126.8, 126.4,
126.3, 123.5, 122.6, 122.1, 121.8, 121.3, 119.6, 113.4, 92.1,
20.6, 20.4. Single-crystal X-Ray diagram: crystal of
compound 5g was grown by slow diffusion of EtOAc into a
solution of compound 5g in CH2Cl2 to yield colorless prisms.
The compound crystallizes in the triclinic crystal system,
space group P -1, a = 7.9733(10) Å , b = 10.7024(14) Å , c =
14.7112(19) Å , V = 1190.3(3) Å 3, Z = 2, dcalcd = 1.419 g/cm3,
F(000) = 528, 2θ range 1.407 to 26.569o, R indices (all data)
R1 = 0.0953, wR2 = 0.2046.
Acetic acid 2-acetoxy-4-(2-naphthalen-1-yl-3-oxo-2,3-
dihydronaphtho[1,2-b]furan-2-yl)-naphthalen-1-yl ester (5k).
5k was synthesized according to general synthetic procedure
from 4k (156 mg, 0.5 mmol). Yield = 75% (104 mg);
Colorless solid; mp > 250 oC (recrystallized from hexanes and
EtOAc); HRMS (ESI-TOF) m/z: [M + H]+ calcd for C36H25O6
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553.1651, found 553.1655; H NMR (400 MHz, CDCl3): δ
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14
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17
18
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22
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24
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26
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8.31 (dd, J = 0.4, 8.0 Hz, 1H), 8.22 (d, J = 8.8 Hz, 1H), 8.14 (d,
J = 8.8 Hz, 1H), 7.92 (d, J = 8.0 Hz, 1H), 7.85 (d, J = 8.4 Hz,
1H), 7.82 (d, J = 8.0 Hz, 1H), 7.80 (d, J = 8.8 Hz, 1H), 7.78 (d,
J = 8.8 Hz, 1H), 7.77 (s, 1H), 7.73 (dt, J = 1.2, 8.0 Hz, 1H),
7.68 (d, J = 8.4 Hz, 1H), 7.59 (dt, J = 1.2, 8.4 Hz, 1H), 7.55 (d,
J = 8.4 Hz, 1H), 7.44-7.36 (m, 3H), 7.29-7.22 (m, 2H), 2.44 (s,
3H), 2.30 (s, 3H); 13C{1H} NMR (100 MHz, CDCl3): δ 198.1,
171.2, 168.1, 167.8, 139.2, 138.04, 137.95, 134.7, 133.0,
132.8, 131.3, 131.0, 130.7, 130.4, 129.0, 128.8, 128.5, 127.0,
126.9, 126.8, 126.3, 126.2, 126.1, 125.9, 125.8, 124.8, 123.4,
122.6, 121.9, 121.63, 121.57, 119.7, 114.5, 95.5, 20.7, 20.4.
Acetic acid 2-acetoxy-4-[2-(4-bromophenyl)-3-oxo-2,3-
dihydronaphtho[1,2-b]furan-2-yl]naphthalen-1-yl ester (5h).
5h was synthesized according to general synthetic procedure
from 4h (170 mg, 0.5 mmol). Yield = 80% (116 mg); White
solid; mp = 210-212 oC (recrystallized from hexanes and
EtOAc); HRMS (ESI-TOF) m/z: [M + H]+ calcd for
1
C32H22BrO6 581.0600, found 581.0608; H NMR (400 MHz,
CDCl3): δ 8.32 (d, J = 8.0 Hz, 1H), 8.24 (d, J = 8.4 Hz, 1H),
7.92 (d, J = 8.4 Hz, 1H), 7.88 (d, J = 8.0 Hz, 1H), 7.80 (s, 1H),
7.74 (dt, J = 1.2, 8.0 Hz, 1H), 7.62 (d, J = 8.0 Hz, 1H), 7.61
(dt, J = 0.8, 8.0 Hz, 1H), 7.54 (d, J = 8.4 Hz, 1H), 7.52 (dd, J
= 1.2, 8.4 Hz, 1H), 7.46-7.41 (m, 3H), 7.28-7.24 (m, 2H), 2.46
(s, 3H), 2.33 (s, 3H); 13C{1H} NMR (100 MHz, CDCl3): δ
197.4, 172.1, 168.2, 167.8, 139.2, 138.4, 137.7, 137.1, 132.0
(2x), 131.2, 130.9, 130.8, 129.2, 128.6, 127.29, 127.25 (2x),
127.0, 126.8, 126.4, 123.5, 122.7, 122.5, 121.9, 121.3, 119.5
(2x), 113.9, 93.7, 20.7, 20.5.
Acetic acid 2-acetoxy-4-[3-oxo-2-(2-trifluoromethylphenyl)-
2,3-dihydronaphtho[1,2-b]furan-2-yl]naphthalen-1-yl
ester
(5l). 5l was synthesized according to general synthetic
procedure from 4l (165 mg, 0.5 mmol). Yield = 70% (100 mg);
o
White solid; mp = 198-200 C (recrystallized from hexanes
and EtOAc); HRMS (ESI-TOF) m/z: [M + H]+ calcd for
1
C33H22F3O6 571.1369, found 571.1375; H NMR (400 MHz,
CDCl3): δ 8.29 (d, J = 8.4 Hz, 1H), 8.23 (d, J = 8.4 Hz, 1H),
7.88-7.81 (m, 3H), 7.74-7.64 (m, 3H), 7.59 (s, 1H), 7.57-7.39
(m, 5H), 7.32-7.30 (m, 1H), 2.44 (s, 3H), 2.31 (s, 3H); 13C{1H}
NMR (100 MHz, CDCl3): δ 197.6, 172.8, 168.1, 167.8, 141.9,
139.1, 138.3, 137.8, 133.4, 132.2, 131.8, 131.0, 130.5, 130.4,
129.4, 128.4, 128.3, 127.6, 127.5, 127.1, 126.8 (d, J = 4.6 Hz),
126.6, 123.3, 123.0, 122.7, 121.9, 121.7 (q, J = 269.3 Hz),
121.6, 119.2, 114.1, 94.4, 20.7, 20.5.
Acetic acid 2-acetoxy-4-[2-(3,5-difluorophenyl)-3-oxo-2,3-
dihydronaphtho[1,2-b]furan-2-yl]naphthalen-1-yl ester (5i).
5i was synthesized according to general synthetic procedure
from 4i (149 mg, 0.5 mmol). Yield = 74% (100 mg); White
solid; mp = 216-218 oC (recrystallized from hexanes and
EtOAc); HRMS (ESI-TOF) m/z: [M + H]+ calcd for
1
C32H21F2O6 539.1306, found 539.1315; H NMR (400 MHz,
CDCl3): δ 8.32 (dd, J = 0.4, 8.4 Hz, 1H), 8.27 (d, J = 8.4 Hz,
1H), 7.91 (d, J = 8.0 Hz, 1H), 7.90 (dd, J = 0.8, 8.0 Hz, 1H),
7.82 (s, 1H), 7.74 (dt, J = 1.2, 8.0 Hz, 1H), 7.63 (d, J = 8.0 Hz,
1H), 7.62 (dt, J = 0.8, 8.0 Hz, 1H), 7.57-7.47 (m, 3H), 6.98-
6.93 (m, 2H), 6.73 (dt, J = 2.0, 8.4 Hz, 1H), 2.46 (s, 3H), 2.33
(s, 3H); 13C{1H} NMR (100 MHz, CDCl3): δ 196.5, 172.0,
168.1, 167.8, 163.3 (d, J = 248.7 Hz), 163.2 (d, J = 247.2 Hz),
142.0 (t, J = 9.1 Hz), 139.2, 138.5, 137.7, 131.4, 130.9, 130.2,
129.3, 128.6, 127.1, 126.9 (2x), 126.6, 123.8, 122.9, 122.5,
122.1, 121.2, 119.4, 113.7, 108.823 (d, J = 27.3 Hz), 108.819
(d, J = 11.4 Hz), 104.0 (t, J = 25.0 Hz), 93.1, 20.7, 20.5.
3-(2-Methoxyphenyl)-2-methylbenzo[h]chromen-4-one (6m).
6m was synthesized according to general synthetic procedure
from 4m (146 mg, 0.5 mmol). Yield = 68% (107 mg); White
solid; mp = 200-202 oC (recrystallized from hexanes and
EtOAc); HRMS (ESI-TOF) m/z: [M + H]+ calcd for C21H17O3
1
317.1178, found 317.1183; H NMR (400 MHz, CDCl3): δ
8.54 (dd, J = 1.6, 7.2 Hz, 1H), 8.19 (d, J = 8.4 Hz, 1H), 7.94
(dd, J = 2.0, 8.0 Hz, 1H), 7.75 (d, J = 8.4 Hz, 1H), 7.70 (dt, J
= 1.6, 7.2 Hz, 1H), 7.67 (dt, J = 1.6, 7.2 Hz, 1H), 7.39 (ddd, J
= 1.6, 7.6, 9.2 Hz, 1H), 7.24 (dd, J = 2.0, 7.6 Hz, 1H), 7.06 (dt,
J = 0.8, 7.2 Hz, 1H), 7.01 (d, J = 8.4 Hz, 1H), 3.79 (s, 3H),
2.39 (s, 3H); 13C{1H} NMR (100 MHz, CDCl3): δ 176.6,
163.0, 157.3, 153.2, 135.7, 131.9, 129.6, 128.9, 128.1, 126.8,
124.7, 124.0, 122.2, 122.0, 121.6, 121.4, 120.7, 119.6, 111.2,
55.6, 19.2.
Acetic acid 2-acetoxy-4-[3-oxo-2-(4-trifluoromethylphenyl)-
2,3-dihydronaphtho[1,2-b]furan-2-yl]naphthalen-1-yl
ester
(5j). 5j was synthesized according to general synthetic
procedure from 4j (165 mg, 0.5 mmol). Yield = 70% (100 mg);
o
White solid; mp = 245-247 C (recrystallized from hexanes
7-Methoxy-2-methyl-3-phenylbenzo[h]chromen-4-one (6n).
6n was synthesized according to general synthetic procedure
from 4n (146 mg, 0.5 mmol). Yield = 66% (104 mg); White
solid; mp = 187-189 oC (recrystallized from hexanes and
EtOAc); HRMS (ESI-TOF) m/z: [M + H]+ calcd for C21H17O3
and EtOAc); HRMS (ESI-TOF) m/z: [M + H]+ calcd for
1
C33H22F3O6 571.1369, found 571.1362; H NMR (400 MHz,
CDCl3): δ 8.34 (d, J = 8.0 Hz, 1H), 8.22 (d, J = 8.4 Hz, 1H),
7.93 (d, J = 8.4 Hz, 1H), 7.89 (dd, J = 0.8, 8.0 Hz, 1H), 7.84 (s,
1H), 7.76 (dt, J = 1.2, 8.0 Hz, 1H), 7.64 (dd, J = 1.2, 8.0 Hz,
1H), 7.62 (t, J = 8.8 Hz, 1H), 7.57-7.50 (m, 6H), 7.47-7.42 (m,
1H), 2.46 (s, 3H), 2.34 (s, 3H); 13C{1H} NMR (100 MHz,
CDCl3): δ 197.1, 172.2, 168.2, 167.8, 141.9, 139.2, 138.5,
137.8, 131.3, 130.9, 130.7, 130.6, 130.4, 129.3, 128.6, 127.1
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317.1178, found 317.1179; H NMR (400 MHz, CDCl3): δ
8.19 (dd, J = 0.8, 9.2 Hz, 1H), 8.16 (d, J = 8.8 Hz, 1H), 8.09
(dt, J = 0.8, 8.4 Hz, 1H), 7.59 (t, J = 8.0 Hz, 1H), 7.49-7.44 (m,
2H), 7.41-7.34 (m, 3H), 7.06 (dd, J = 0.8, 8.0 Hz, 1H), 4.05 (s,
3H), 2.47 (s, 3H); 13C{1H} NMR (100 MHz, CDCl3): δ 176.8,
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162.5, 155.5, 152.9, 133.1, 130.4 (2x), 128.4 (2x), 127.8,
127.6, 127.2, 124.9, 124.7, 120.5, 120.1, 119.0, 114.0, 107.3,
55.7, 19.4.
2x), 129.4 (2x), 129.1 (d, J = 3.1 Hz), 125.9, 121.4 (2x), 115.6
(d, J = 21.3 Hz, 2x), 40.5.
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Biphenyl-4-ylacetic acid phenyl ester (8c). 8c was
synthesized according to general synthetic procedure from 7
(94 mg, 1.0 mmol) and 2e (223 mg, 1.05 mmol). Yield = 95%
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7-Methoxy-2-methyl-3-phenylbenzo[h]chromen-4-one (6o).
6o was synthesized according to general synthetic procedure
from 4o (146 mg, 0.5 mmol). Yield = 57% (90 mg); White
solid; mp = 192-194 oC (recrystallized from hexanes and
EtOAc); HRMS (ESI-TOF) m/z: [M + H]+ calcd for C21H17O3
o
(274 mg); White solid; mp = 107-109 C (recrystallized from
hexanes and EtOAc); HRMS (ESI-TOF) m/z: [M + H]+ calcd
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for C20H17O2 289.1229, found 289.1236; H NMR (400 MHz,
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317.1178, found 317.1170; H NMR (400 MHz, CDCl3): δ
CDCl3): δ 7.63-7.60 (m, 4H), 7.49-7.44 (m, 4H), 7.41-7.35 (m,
3H), 7.26-7.21 (m, 1H), 7.12-7.08 (m, 2H), 3.92 (s, 2H);
13C{1H} NMR (100 MHz, CDCl3): δ 170.0, 150.7, 140.7,
140.3, 132.4, 129.7 (2x), 129.4 (2x), 128.8 (2x), 127.4 (2x),
127.3, 127.1 (2x), 125.9, 121.4 (2x), 41.0.
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8.51-8.49 (m, 1H), 8.37-8.35 (m, 1H), 7.74-7.69 (m, 2H),
7.89-7.45 (m, 2H), 7.43 (s, 1H), 7.41-7.34 (m, 3H), 4.09 (s,
3H), 2.46 (s, 3H); 13C{1H} NMR (100 MHz, CDCl3): δ 176.5,
162.0, 152.6, 148.3, 133.3, 130.5 (2x), 128.7, 128.6, 128.4
(2x), 127.8, 127.5, 124.9, 124.1, 122.7, 122.0, 120.1, 96.7,
56.0, 19.4.
(3,5-Difluorophenyl)acetic acid phenyl ester (8d). 8d was
synthesized according to general synthetic procedure from 7
(94 mg, 1.0 mmol) and 2i (181 mg, 1.05 mmol). Yield = 94%
(233 mg); Colorless oil; HRMS (ESI-TOF) m/z: [M + H]+
calcd for C14H11F2O2 249.0727, found 249.0733; 1H NMR
(400 MHz, CDCl3): δ 7.42-7.37 (m, 2H), 7.27-7.23 (m, 1H),
7.11-7.08 (m, 2H), 6.98-6.92 (m, 2H), 6.78 (tt, J = 2.4, 9.2 Hz,
1H), 3.85 (s, 2H); 13C{1H} NMR (100 MHz, CDCl3): δ 168.8,
163.1 (d, J = 247.2 Hz), 162.9 (d, J = 247.8 Hz), 150.5, 136.8
(t, J = 9.8 Hz), 129.4 (2x), 126.0, 121.3 (2x), 112.386 (d, J =
25.7 Hz), 112.385 (d, J = 12.1 Hz), 102.9 (t, J = 25.0 Hz), 40.8
(d, J = 2.3 Hz).
6-Chloro-2-methyl-3-phenylbenzo[h]chromen-4-one (6p). 6p
was synthesized according to general synthetic procedure from
4p (148 mg, 0.5 mmol). Yield = 54% (86 mg); White solid;
o
mp = 184-186 C (recrystallized from hexanes and EtOAc);
HRMS (ESI-TOF) m/z: [M + H]+ calcd for C20H14ClO2
1
321.0682, found 321.0686; H NMR (400 MHz, CDCl3): δ
8.55 (dd, J = 0.8, 8.0 Hz, 1H), 8.37 (dd, J = 0.8, 8.0 Hz, 1H),
8.26 (s, 1H), 7.83 (dt, J = 1.6, 8.4 Hz, 1H), 7.75 (dt, J = 1.6,
8.4 Hz, 1H), 7.50-7.45 (m, 2H), 7.42-7.38 (m, 1H), 7.35-7.33
(m, 2H), 2.48 (s, 3H); 13C{1H} NMR (100 MHz, CDCl3): δ
176.5, 162.6, 151.9, 132.8, 132.7, 130.3 (2x), 130.0, 128.9,
128.5 (2x), 128.0, 127.7, 125.1, 125.0, 124.9, 122.5, 121.1,
119.8, 19.4.
(2-Nitrophenyl)acetic acid phenyl ester (8e). 8e was
synthesized according to general synthetic procedure from 7
(94 mg, 1.0 mmol) and 2n (190 mg, 1.05 mmol). Yield = 94%
(241 mg); Colorless oil; HRMS (ESI-TOF) m/z: [M + H]+
calcd for C14H12NO4 258.0766, found 258.0771; 1H NMR (400
MHz, CDCl3): δ 8.18 (dd, J = 1.2, 8.0 Hz, 1H), 7.64 (dt, J =
1.2, 7.6 Hz, 1H), 7.51 (dt, J = 1.6, 8.0 Hz, 1H), 7.45 (dd, J =
1.2, 8.0 Hz, 1H), 7.39-7.34 (m, 2H), 7.22 (dt, J = 1.2, 8.4 Hz,
1H), 7.13-7.10 (m, 2H), 4.26 (s, 2H); 13C{1H} NMR (100 MHz,
CDCl3): δ 168.6, 150.6, 148.6, 133.8, 133.5, 129.5, 129.4 (2x),
128.9, 126.0, 125.5, 121.5 (2x), 40.1.
General synthetic procedure of compounds 8a-8f is as
follows: Trifluoroacetic anhydride (TFAA, 230 mg, 1.1 mmol)
and phosphoric acid (H3PO4, 110 mg, 1.1 mmol) were added
to a solution of substituted arylacetic acids 2a, 2c, 2e, 2i, 2n,
o
2g (1.05 mmol) in MeCN (15 mL) at 25 C. The reaction
o
mixture was stirred at 25 C for 30 min. Phenol 7 (94 mg, 1.0
mmol) in MeCN (5 mL) was added to the reaction mixture at
o
25 oC. The reaction mixture was stirred at 25 C for 20 h. The
solvent of reaction mixture was concentrated. The residue was
diluted with water (10 mL) and the mixture was extracted with
CH2Cl2 (3 x 20 mL). The combined organic layers were
washed with brine, dried, filtered and evaporated to afford
crude product under reduced pressure. Purification on silica
gel (hexanes/EtOAc = 10/1~1/1) afforded compounds 8a-8f.
Thiophen-2-ylacetic acid phenyl ester (8f). 8f was
synthesized according to general synthetic procedure from 7
(94 mg, 1.0 mmol) and 2g (149 mg, 1.05 mmol). Yield = 90%
(196 mg); Colorless oil; HRMS (ESI-TOF) m/z: [M + H]+
calcd for C12H11O2S 219.0480, found 219.0483; 1H NMR (400
MHz, CDCl3): δ 7.44-7.38 (m, 2H), 7.29 (dd, J = 1.2, 5.2 Hz,
1H), 7.28-7.24 (m, 1H), 7.16-7.13 (m, 2H), 7.10-7.08 (m, 1H),
7.04 (dd, J = 3.6, 5.2 Hz, 1H), 4.11 (br d, J = 0.8 Hz, 2H);
13C{1H} NMR (100 MHz, CDCl3): δ 168.8, 150.5, 134.3,
129.3 (2x), 127.0, 126.8, 125.9, 125.2, 121.3 (2x), 35.4.
Phenylacetic acid phenyl ester (8a). 8a was synthesized
according to general synthetic procedure from 7 (94 mg, 1.0
mmol) and 2a (143 mg, 1.05 mmol). Yield = 93% (197 mg);
Colorless oil; HRMS (ESI-TOF) m/z: [M + H]+ calcd for
C14H13O2 213.0916, found 213.0923; 1H NMR (400 MHz,
CDCl3): δ 7.42-7.30 (m, 7H), 7.25-7.20 (m, 1H), 7.09-7.06 (m,
2H), 3.87 (s, 2H); 13C{1H} NMR (100 MHz, CDCl3): δ 170.0,
150.7, 133.4, 129.4 (2x), 129.3 (2x), 128.7 (2x), 127.3, 125.8,
121.4 (2x), 41.4.
General synthetic procedure of compounds 9a-9e is as
follows: AlCl3 (270 mg, 2.0 mmol) was added to a solution of
8a-8e (1.0 mmol) in dry MeNO2 (10 mL) at 0 oC. The reaction
mixture was stirred at reflux for 2 h. Water (1 mL) was added
to the reaction mixture. The solvent of reaction mixture was
concentrated. The residue was diluted with water (10 mL) and
the mixture was extracted with CH2Cl2 (3 x 20 mL). The
combined organic layers were washed with brine, dried,
filtered and evaporated to afford crude product under reduced
pressure. Purification on silica gel (hexanes/EtOAc = 10/1~1/1)
afforded compounds 9a-9e.
(4-Fluorophenyl)acetic acid phenyl ester (8b). 8a was
synthesized according to general synthetic procedure from 7
(94 mg, 1.0 mmol) and 2c (162 mg, 1.05 mmol). Yield = 96%
(221 mg); Colorless oil; HRMS (ESI-TOF) m/z: [M + H]+
calcd for C14H12FO2 231.0821, found 231.0824; 1H NMR (400
MHz, CDCl3): δ 7.40-7.34 (m, 4H), 7.26-7.21 (m, 1H), 7.10-
7.04 (m, 4H), 3.84 (s, 2H); 13C{1H} NMR (100 MHz, CDCl3):
δ 169.8, 162.1 (d, J = 244.1 Hz), 150.6, 130.9 (d, J = 7.6 Hz,
1-(2-Hydroxyphenyl)-2-phenylethanone (9a). 9a was
synthesized according to general synthetic procedure from 8a
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7
8
(212 mg, 1.0 mmol). Yield = 70% (148 mg); Colorless oil;
8.0 Hz, 1H), 7.65 (dt, J = 1.6, 7.6 Hz, 1H), 7.55-7.50 (m, 2H),
HRMS (ESI-TOF) m/z: [M + H]+ calcd for C14H13O2 213.0916,
7.36 (dd, J = 1.2, 8.0 Hz, 1H), 7.01 (dd, J = 0.8, 8.4 Hz, 1H),
6.98 (dt, J = 1.2, 8.0 Hz, 1H), 4.79 (s, 2H); 13C{1H} NMR
(100 MHz, CDCl3): δ 201.2, 162.5, 149.3, 136.8, 133.7, 133.6,
129.7, 128.7, 125.4, 119.2, 119.0, 118.7, 114.5, 43.7.
1
found 213.0920; H NMR (400 MHz, CDCl3): δ 12.22 (d, J =
0.4 Hz, 1H), 7.87 (dd, J = 1.6, 8.0 Hz, 1H), 7.48 (dt, J = 1.6,
8.4 Hz, 1H), 7.38-7.34 (m, 2H), 7.31-7.27 (m, 3H), 6.99 (dd, J
= 1.2, 8.4 Hz, 1H), 6.91 (dt, J = 1.2, 8.0 Hz, 1H), 4.31 (s, 2H);
13C{1H} NMR (100 MHz, CDCl3): δ 203.9, 162.9, 136.6,
133.9, 130.4, 129.4 (2x), 128.8 (2x), 127.2, 119.1, 119.0,
118.7, 45.1.
General synthetic procedure of compounds 10a-10c is as
follows: NaH (60% in oil, 80 mg, 2.0 mmol) was added to a
solution of 9a-9c (1.0 mmol) in dry THF (15 mL) at 0 oC. The
9
o
reaction mixture was stirred at 25 C for 30 min. Ac2O (310
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2-(4-Fluorophenyl)-1-(2-hydroxyphenyl)ethanone (9b). 9b
was synthesized according to general synthetic procedure from
8b (230 mg, 1.0 mmol). Yield = 64% (147 mg); Colorless oil;
HRMS (ESI-TOF) m/z: [M + H]+ calcd for C14H12FO2
mg, 3.0 mmol) in dry THF (5 mL) was added to the reaction
mixture at 25 oC. The reaction mixture was stirred at 25 oC for
20 h. The solvent of reaction mixture was concentrated. The
residue was diluted with water (10 mL) and the mixture was
extracted with CH2Cl2 (3 x 20 mL). The combined organic
layers were washed with brine, dried, filtered and evaporated
to afford crude product under reduced pressure. Purification
on silica gel (hexanes/EtOAc = 10/1~1/1) afforded compounds
10a-10c.
1
231.0821, found 231.0826; H NMR (400 MHz, CDCl3): δ
12.17 (s, 1H), 7.85 (dd, J = 1.6, 8.0 Hz, 1H), 7.49 (dt, J = 1.6,
8.4 Hz, 1H), 7.26-7.21 (m, 2H), 7.08-7.03 (m, 2H), 7.00 (dd, J
= 1.2, 8.4 Hz, 1H), 6.92 (dt, J = 1.6, 8.4 Hz, 1H), 4.29 (s, 2H);
13C{1H} NMR (100 MHz, CDCl3): δ 203.5, 162.8, 162.0 (d, J
= 244.1 Hz), 136.7, 131.0 (d, J = 8.4 Hz, 2x), 130.2, 129.5 (d,
J = 3.7 Hz), 119.0, 118.9, 118.7, 115.6 (d, J = 21.2 Hz, 2x),
44.1.
2-Methyl-3-phenylchromen-4-one (10a). 10a was synthesized
according to general synthetic procedure from 9a (212 mg, 1.0
mmol). Yield = 76% (179 mg); Colorless oil; HRMS (ESI-
TOF) m/z: [M + H]+ calcd for C16H13O2 237.0916, found
2-Biphenyl-4-yl-1-(2-hydroxyphenyl)ethanone (9c). 9c was
synthesized according to general synthetic procedure from 8c
(288 mg, 1.0 mmol). Yield = 69% (199 mg); White solid; mp
=105-107 oC (recrystallized from hexanes and EtOAc); HRMS
(ESI-TOF) m/z: [M + H]+ calcd for C20H17O2 289.1229, found
1
237.0922; H NMR (400 MHz, CDCl3): δ 8.24 (ddd, J = 0.8,
2.0, 8.0 Hz, 1H), 7.66 (dt, J = 1.6, 8.4 Hz, 1H), 7.46-7.35 (m,
5H), 7.31-7.28 (m, 2H), 2.33 (s, 3H); 13C{1H} NMR (100
MHz, CDCl3): δ 176.8, 163.3, 155.9, 133.3, 133.1, 130.4 (2x),
128.4 (2x), 127.8, 126.3, 124.8, 123.7, 123.5, 117.6, 19.5.
1
289.1234; H NMR (400 MHz, CDCl3): δ 12.23 (s, 1H), 7.90
(dd, J = 1.6, 8.0 Hz, 1H), 7.60-7.58 (m, 4H), 7.49 (dt, J = 1.6,
8.4 Hz, 1H), 7.46-7.42 (m, 2H), 7.37-7.33 (m, 3H), 7.01 (dt, J
= 1.2, 8.4 Hz, 1H), 6.93 (dt, J = 1.2, 8.0 Hz, 1H), 4.29 (s, 2H);
13C{1H} NMR (100 MHz, CDCl3): δ 203.8, 162.9, 140.7,
140.2, 136.6, 132.9, 130.4, 129.9 (2x), 128.8 (2x), 127.5 (2x),
127.3 (2x), 127.1 (2x), 119.0, 118.7, 44.5.
3-(4-Fluorophenyl)-2-methylchromen-4-one (10b). 10b was
synthesized according to general synthetic procedure from 9b
(230 mg, 1.0 mmol). Yield = 80% (203 mg); White solid; mp
o
= 94-96 C (recrystallized from hexanes and EtOAc); HRMS
(ESI-TOF) m/z: [M + H]+ calcd for C16H12FO2 255.0821,
1
found 255.0826; H NMR (400 MHz, CDCl3): δ 8.23 (dd, J =
2-(3,5-Difluorophenyl)-1-(2-hydroxyphenyl)ethanone (9d).
9d was synthesized according to general synthetic procedure
from 8d (248 mg, 1.0 mmol). Yield = 70% (174 mg); White
solid; mp = 114-116 oC (recrystallized from hexanes and
EtOAc); HRMS (ESI-TOF) m/z: [M + H]+ calcd for
2.0, 8.0 Hz, 1H), 7.67 (dt, J = 1.6, 8.4 Hz, 1H), 7.45 (dd, J =
1.2, 8.4 Hz, 1H), 7.40 (dt, J = 1.2, 8.0 Hz, 1H), 7.29-7.24 (m,
2H), 7.16-7.10 (m, 2H), 2.32 (s, 3H); 13C{1H} NMR (100
MHz, CDCl3): δ 176.8, 163.6, 162.2 (d, J = 255.4 Hz), 155.9,
133.5, 132.2 (d, J = 8.4 Hz, 2x), 128.9, 126.3, 124.9, 123.4,
122.7, 117.7, 115.4 (d, J = 21.2 Hz, 2x), 19.5.
1
C14H11F2O2 249.0727, found 249.0732; H NMR (400 MHz,
CDCl3): δ 12.05 (s, 1H), 7.80 (dd, J = 1.6, 8.0 Hz, 1H), 7.51
(dt, J = 1.6, 8.4 Hz, 1H), 7.01 (dd, J = 1.2, 8.4 Hz, 1H), 6.93
(dt, J = 1.2, 8.4 Hz, 1H), 6.84-6.77 (m, 2H), 6.74 (tt, J = 2.4,
8.8 Hz, 1H), 4.28 (s, 2H); 13C{1H} NMR (100 MHz, CDCl3): δ
202.2, 163.1 (d, J = 247.2 Hz), 163.0 (d, J = 247.1 Hz), 162.9,
137.3 (t, J = 9.1 Hz), 136.9, 130.0, 119.2, 118.83, 118.77,
112.6 (d, J = 25.8 Hz), 112.6 (d, J = 12.1 Hz), 102.8 (t, J =
25.0 Hz), 44.4 (t, J = 1.5 Hz). Single-crystal X-Ray diagram:
crystal of compound 9d was grown by slow diffusion of
EtOAc into a solution of compound 9d in CH2Cl2 to yield
colorless prisms. The compound crystallizes in the monoclinic
crystal system, space group P 21/c, a = 7.9744(3) Å , b =
20.0084(6) Å , c = 7.1794(2) Å , V = 1112.54(6) Å 3, Z = 4, dcalcd
= 1.482 g/cm3, F(000) = 512, 2θ range 2.036 to 26.406o, R
indices (all data) R1 = 0.0356, wR2 = 0.0822.
3-Biphenyl-4-yl-2-methylchromen-4-one (10c). 10c was
synthesized according to general synthetic procedure from 9c
(288 mg, 1.0 mmol). Yield = 78% (243 mg); White solid; mp
= 162-164 oC (recrystallized from hexanes and EtOAc);
HRMS (ESI-TOF) m/z: [M + H]+ calcd for C22H17O2 313.1229,
1
found 313.1235; H NMR (400 MHz, CDCl3): δ 8.26 (dd, J =
1.6, 8.0 Hz, 1H), 7.70-7.63 (m, 5H), 7.48-7.35 (m, 7H), 2.39 (s,
3H); 13C{1H} NMR (100 MHz, CDCl3): δ 176.8, 163.3, 155.9,
140.9, 140.6, 133.4, 132.1, 130.8 (2x), 128.8 (2x), 127.3,
127.2 (4x), 126.3, 124.8, 123.5, 123.3, 117.6, 19.6.
Phenylacetic acid naphthalen-2-yl ester (12). Trifluoroacetic
anhydride (TFAA, 230 mg, 1.1 mmol) and phosphoric acid
(H3PO4, 110 mg, 1.1 mmol) were added to a solution of
phenylacetic acid (2a, 1.05 mmol) in MeCN (15 mL) at 25 oC.
The reaction mixture was stirred at 25 oC for 30 min. 2-
Naphthol 11 (144 mg, 1.0 mmol) in MeCN (5 mL) was added
1-(2-Hydroxyphenyl)-2-(2-nitrophenyl)ethanone (9e). 9e was
synthesized according to general synthetic procedure from 8e
(257 mg, 1.0 mmol). Yield = 45% (116 mg); Colorless oil;
HRMS (ESI-TOF) m/z: [M + H]+ calcd for C14H12NO4
o
to the reaction mixture at 25 C. The reaction mixture was
o
stirred at 25 C for 20 h. The solvent of reaction mixture was
concentrated. The residue was diluted with water (10 mL) and
the mixture was extracted with CH2Cl2 (3 x 20 mL). The
1
258.0766, found 258.0760; H NMR (400 MHz, CDCl3): δ
11.83 (s, 1H), 8.19 (dd, J = 1.2, 8.4 Hz, 1H), 7.91 (dd, J = 1.6,
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The Journal of Organic Chemistry
M.; Bartolucci, S.; Piersanti, G. Organocatalytic Aza-Friedel-
combined organic layers were washed with brine, dried,
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Crafts/Lactonization Domino Reaction of Naphthols and Phe-
nols with 2-Acetamidoacrylate to Naphtho- and Benzofuranones
Bearing a Quaternary Center at the C3 Position. J. Org. Chem.
2018, 83, 12275-12283.
filtered and evaporated to afford crude product under reduced
pressure. Purification on silica gel (hexanes/EtOAc = 10/1~1/1)
afforded compound 12. Yield = 95% (249 mg); White solid;
mp = 85-87 oC (recrystallized from hexanes and EtOAc);
HRMS (ESI-TOF) m/z: [M + H]+ calcd for C18H15O2 263.1072,
found 263.1078; 1H NMR (400 MHz, CDCl3): δ 7.89-7.86 (m,
2H), 7.84-7.82 (m, 1H), 7.61 (d, J = 2.0 Hz, 1H), 7.55-7.43 (m,
6H), 7.41-7.37 (m, 1H), 7.26 (dd, J = 2.4, 8.8 Hz, 1H), 3.97 (s,
2H); 13C{1H} NMR (100 MHz, CDCl3): δ 170.1, 148.3, 133.6,
133.4, 131.4, 129.30, 129.28 (2x), 128.7 (2x), 127.7, 127.6,
127.3, 126.5, 125.6, 120.9, 118.4, 41.4.
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(6) Satoh, T.; Tsuda, T.; Kushino, Y.; Miura, M.; Nomura, M. Syn-
thesis of Naphthofuran-2(3H)-one Derivatives by Palladium-
Catalyzed Three-Component Coupling Using Naphthols, Alde-
hydes, and Carbon Monoxide. J. Org. Chem. 1996, 61, 6476-
6477.
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(7) Synthesis of other linear naphtho-fused furanone derivatives, see:
(a) Kao, T.-T.; Lin, C.-C.; Shia, K.-S. The Total Synthesis of
Retrojusticidin B, Justicidin E, and Helioxanthin. J. Org. Chem.
2015, 80, 6708-6714. (b) Mal, D.; Jana, S. Transpositive Tan-
dem Annulation of Phthalides with Allene Carboxylates: Regi-
oselective Synthesis of Arylnaphthalene Lignans. J. Org. Chem.
2016, 81, 11857-11865. (c) Nimnual, P.; Norseeda, K.; Ak-
kachairin, B.; Tummatorn, J.; Laohapaisan, P.; Supantanapong,
N. Chuangsoongnern, P.; Thongsornkleeb, C.; Sittihan, S.;
Ruchirawat, S.; Rodphon, W. Synthesis of β-Naphthols and
Naphthofuranones from o-Alkynylarylketones via Sequential
AgTFA-Catalyzed Ketonization-Intramolecular Aldol Conden-
sation: Total Synthesis of Negundin A. Asian J. Org. Chem.
2018, 7, 932-945. (d) Jana, S.; Mal, D. Anionic Annulation of 3-
ASSOCIATED CONTENT
Supporting Information
Scanned photocopies of NMR spectral data for all compounds
and X-ray analysis data of 4e, 4h 5a, 5g and 9d. This infor-
mation is available free of charge via the Internet at http:
//pubs.acs.org.
AUTHOR INFORMATION
Cyanophthalides with Allene Carboxylates:
A
Carbon-
Corresponding Author
*Email: mychang@kmu.edu.tw
ORCID
Conserved Synthesis of Naphtho[b]furanones. J. Org. Chem.
2018, 83, 4537-4544.
(8) Examples on reductive dimerizations, see: (a) Mesganaw, T.; Im,
G. Y. J.; Garg, N. K. Synthesis of Diphenylhexatriene by the Pd-
Catalyzed Dimerization of Cinnamyl Acetate. J. Org. Chem.
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A.; Fallis, A. G. Synthesis of Diynes and Tetraynes from in Situ
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Syntheses of α-Pyrones Using Gold-Catalyzed Coupling Reac-
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H. F. Increased Activity of in Situ Catalysts for Alkyne Metathe-
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(9) CCDC 1894542 (4e), 1894541 (4h), 1894548 (5a), 1894543
(5g), and 1894544 (9d) contain the supplementary crystallo-
graphic data for this paper. This data can be obtained free of
charge via www.ccdc.cam.ac.uk/conts/retrieving.html (or from
the CCDC, 12 Union Road, Cambridge CB2 1EZ, UK; fax: 44-
1223-336033; e-mail: deposit@ccdc.cam.ac.uk).
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Ali, T. E.; Alnamer, Y. A.; Gabr, Y. A. Synthesis and Chemical
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Chromone: A Valid Scaffold in Medicinal Chemistry. Chem.
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One-Pot Synthesis of Benzopyran-4-ones with Cancer Preven-
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Meng-Yang Chang: 0000-0002-1983-8570
Notes
The authors declare no competing financial interest.
ACKNOWLEDGMENT
The authors would like to thank the Ministry of Science and
Technology of the Republic of China for financial support
(MOST 106-2628-M-037-001-MY3).
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