The first synthesis of natural occurring juncaceae coumarin, 9-hydroxy-8-methyl-3H-benzo[f]chromen-3-one, featuring a one-pot rearrangement and aromatization cascade

Article abstract of DOI:10.1002/jccs.201100481

The synthesis of benzocoumarins from β-tetralones has been achieved via two pathways in the first total synthesis of the Juncaceae natural product, 9-hydroxy-8-methyl-3H-benzo[f]chromen-3-one, featuring a one-pot rearrangement and aromatization cascade.

Full text of DOI:10.1002/jccs.201100481

JOURNAL OF THE CHINESE
CHEMICAL SOCIETY
Article
The First Synthesis of Natural Occurring Juncaceae Coumarin, 9-Hydroxy-8-methyl-
3H-benzo[f]chromen-3-one, Featuring a One-pot Rearrangement and Aromatization
Cascade
Yung-Son Hon,†,* Ya-Chun Hong, Bor-Cherng Hong* and Ju-Hsiou Liao
Department of Chemistry and Biochemistry, National Chung Cheng University, Chia-Yi 62102, Taiwan, R.O.C.
(Received: Aug. 4, 2011; Accepted: Sept. 13, 2011; Published Online: Nov. 16, 2011; DOI: 10.1002/jccs.201100481)
The synthesis of benzocoumarins from b-tetralones has been achieved via two pathways in the first total
synthesis of the Juncaceae natural product, 9-hydroxy-8-methyl-3H-benzo[f]chromen-3-one, featuring a
one-pot rearrangement and aromatization cascade.
Keywords: Rearrangement; Total synthesis; Juncaceae; Coumarin.
INTRODUCTION
Coumarins (2H-chromen-2-ones) are found in plants
NaH and tert-butyl carbonate in toluene at 100 °C for 4 h
provided the ketoester 2a in 82% yield (Scheme II). Treat-
ment of 2a with DDQ in dioxane at 100 °C for 8 h gave an
89% yield of the enone 3a. Exposure of 3a to propargylic
acid and trifluoroacetic acid in toluene at 100 °C for 2 h af-
forded a 74% yield of coumarin 4a. The mechanism of this
transformation probably involved a decarboxylation of 3a
to afford 2-naphthol, followed by esterification with pro-
pargylic acid, a subsequent Claisen rearrangement, and
aromatization through the Friedel-Crafts alkylation of
2-naphthol and propargylic acid, followed by esterification
and aromatization.25 Alternatively, the mechanism may in-
volve the Michael reaction of ketoester 3a with propargylic
acid, followed by isomerization, decarboxylation, and lac-
tonization to yield 4a. The three-step transformation of
b-tetralone (1a) to coumarin 4a can be achieved in a one-
pot synthesis without purification of the intermediates to
give a 54% total yield of coumarin 4a. A series of 5,6-ben-
zocoumarins were then prepared via this protocol (Table
1). Most of the reactions afforded the derivatives in good
yields; however, a few examples containing strong elec-
tron-donating substituents, for example, methoxy groups,
gave particularly low yields at the 3rd step reaction.
that display a wide spectrum of biological activities, and
they have been used widely used in perfumes, foods, and
pesticide since their discovery in the 19th century. Many bi-
ological studies of coumarins have been reported (Scheme
I).1 Recently, coumarins have been used in the pharmaceu-
tical industry, for example, in the synthetic anticoagulant
pharmaceuticals, dicoumarol and warfarin. More recently,
several allelopathic phenanthrenoids and benzocoumarins
with algicidal activity have been isolated from Juncus
acutus.2 Given their history and application potential, ex-
tensive efforts have been devoted to the synthesis of
coumarin derivatives.3 Synthetic approaches to the
coumarins have employed the Pechmann reaction,4 Perkin
reaction,5 Knoevenagel condensation,6 Wittig reaction,7
Peterson olefination,8 Claisen rearrangement,9 Friedel-
Craft reaction,10 and metal catalyzed reactions, including
Ni-,11 Pd-,12 Ru-,13 Pt-,14 Au-,15 Rh-,16 Yb-,17 In-,18 Hf-,19
Cu-,20 Fe-catalyzed reactions.21
Continuing of our efforts toward the synthesis of
benzocoumarins,22 we envisioned that an unprecedented
and convenient synthesis of 5,6-benzocoumarin from b-
tetralone23 could be achieved via a one-pot rearrangement
and aromatization cascade (Scheme II). Herein, we report
such a case and describe the first total synthesis of the natu-
rally occurring Juncaceae coumarin, 6-hydroxy-7-methyl-
5a,8a-benzocoumarin.24
On the other hand, coumarin 4a could be prepared
more efficiently in a 66% yield from b-tetralone (1a) in a
two-step sequence, without isolation of the intermediate
5a, by a reaction with propargylic acid and trifluoroacetic
acid, followed by the subsequent aromatization with DDQ
(Scheme II). The methodology was applied toward the syn-
thesis of variant 5,6-benzocoumarins with good yields.
Nevertheless, as seen in the previous protocol, much lower
RESULTS AND DISCUSSION
In a first step, the reaction of b-tetralone (1a) with
Dedicated to the memory of Professor Yung-Son Hon (1955–2011).
† Deceased on June 16, 2011.
* Corresponding author. Tel: +886-5-2428174; Fax: +886-5-2721040; E-mail: chebch@ccu.edu.tw
J. Chin. Chem. Soc. 2012, 59, 407-420
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Hon et al.
Scheme I Select examples of biologically active and natural occurring benzocoumarins
yields were obtained for the derivatives containing meth-
oxy groups (Table 2).
b-tetralones was achieved via two pathways. One of the de-
rivatives prepared by this method, 4i, was transformed to
9-hydroxy-8-methyl-3H-benzo[f]chromen-3-one (6) to
provide a first total synthesis of the Juncaceae natural
product.
The structure of the product 4i was confirmed by
X-ray analysis of a single crystal (Fig. 1). Deprotection of
the methoxy group of 4i was achieved by treatment with
BBr3 in CH2Cl2 at 0 °C at room temperature for 12 h, which
provided 83% yield of the Juncaceae coumarin, 9-hy-
droxy-8-methyl-3H-benzo[f]chromen-3-one (6), Scheme
III.24
EXPERIMENTAL SECTION
Reactions were normally carried out under nitrogen
atmosphere in glassware. Merck silica gel 60 (particle size
0.04-0.063 mm) was employed for flash chromatography.
In summary, the synthesis of benzocoumarins from
Scheme II Syntheses of 5,6-benzocoumarin from b-tetralone
408
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Synthesis of Natural Occurring Juncaceae Coumarin
Table 1. First-generation synthesis of 5,6-benzocoumarin from b-tetralone
NaH, toluene,
CO(OtBu)2,
100 °C, 4 h
R4
R4 CO2tBu
O
DDQ, dioxane,
100 °C, 8 h
R3
R2
O
R3
R2
1
R1 R5
2
R1 R5
O
R4
R4 CO2tBu
O
HC CCO2H, HOTf
toluene, 100 °C, 2 h
R3
R2
O
R3
R2
4
3
R1 R5
R1 R5
Entry
Product
2 yielda (%) 3 yielda (%) 4 yielda (%)
1
a R1 = R2 = R3 = R4 = R5 = H
82
76
71
76
85
95
81
83
55
60
86
95
84
75
71
98
96
89
81
65
52
73
79
70
63
72
75
97
74
70
82
48
81
86
74
67
46
64
40
15
79
55
21
27
12
65
60
70
53
84
37
2
b R1 = CH3, R2 = R3 = R4 = R5 = H
c R1 = OCH3, R2 = R3 = R4 = R5 = H
d R2 = OCH3, R1 = R3 = R4 = R5 = H
e R3 = OCH3, R1 = R2 = R4 = R5 = H
f R4 = OCH3, R1 = R2 = R3 = R5 = H
g R3 = Br, R1 = R2 = R4 = R5 = H
h R1 = R3 = CH3, R2 = R4 = R5 = H
i R2 = CH3, R3 = OCH3, R1 = R4 = R5 = H
j R2 = R3 = OCH3, R1 = R4 = R5 = H
k R1 = R4 = OCH3, R2 = R3 = R5 = H
l R5 = CH3, R1 = R2 = R3 = R4 = H
m R5 = Ph, R1 = R2 = R3 = R4 = H
n R3 = CH3, R1 = R2 = R4 = R5 = H
o R1 = R4 = CH3, R2 = R3 = R5 = H
p R2 = Br, R1 = R3 = R4 = R5 = H
q R1 = R2 = R3 = Ar, R4 = R5 = H
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
a Isolated yields for the one-step reaction. b Isolated yields of 4, three steps from 1.
Melting points are uncorrected. 1H NMR spectra were ob-
tained in CDCl3 unless otherwise noted at 400 MHz
(Bruker DPX-400) or 500 MHz (Varian-Unity INOVA-
500). 13C NMR spectra were obtained at 100 MHz or 125
MHz. The melting point was recorded on a melting point
apparatus (MPA100 – Automated melting point system,
Stanford Research Systems, Inc.) and is uncorrected.
Typical experimental procedure for the preparation
of coumarin 4a (1st generation)
Preparation of 2a
To a solution of NaH (219 mg, 5.47 mmol) in toluene
(3 mL) was added dropwise a solution of b-tetralone (1a,
200 mg, 1.37 mmol) in toluene (4 mL), followed by the ad-
dition of di-tert-butyl dicarbonate (0.47 mL, 2.05 mmmol).
The solution was heated to 100 °C and stirred for 4 h until
the completion of reaction, monitored by TLC. The solu-
tion was cooled to 0 °C, followed by slow addition of 1 N
aqueous HCl solution to quench the reaction. The reaction
mixture was extracted by EtOAc, and the organic extract
was dried over MgSO4, and concentrated in vacuo to give
the crude product. The residue was purified by flash col-
umn chromatography with 4% EtOAc-hexane (Rf = 0.69
for 2a, in 1:10 EtOAc-hexane) to give 2a as a white solid
Fig. 1. ORTEP plot of the X-ray crystal structure of 4i.
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Table 2. One-pot synthesis of 5,6-benzocoumarin from b-
reaction, monitored by TLC. The solution was concen-
trated in vacuo to give the crude product. The residue was
purified by flash column chromatography with 4% EtOAc-
hexane (Rf = 0.69 for 3a, in 1:10 EtOAc-hexane; dark pur-
ple color for 3a, and sky blue color for 2a on TLC with the
Vanillin stain) to give 3a as a white solid (162 mg, 89%
yield). Mp 74-76 °C. Spectroscopic data for 3a: 1H NMR
(CDCl3, 400 MHz): d 7.85-7.79 (m, 3 H), 7.63 (d, J = 2.4
Hz, 1 H), 7.49-7.45 (m, 2 H), 7.31 (dd, J = 8.8, 2.4 Hz, 1 H),
1.59 (s, 9 H); 13C NMR (CDCl3, 100 MHz): d 152.0 (C),
148.7 (C), 133.7 (C), 131.4 (C), 129.4 (CH), 127.70 (CH),
127.67 (CH), 126.5 (CH), 125.7 (CH), 120.9 (CH), 118.1
(CH), 83.6 (C), 27.7 (three CH3); IR (neat): 3058, 2980,
2931, 1753, 1634, 1601, 1510, 1465, 1370, 1277, 1239,
1145, 957, 867, 754 cm-1; MS (m/z, relative intensity): 244
(M+, 23), 145 (11), 144 (100), 127 (22), 115 (67), 57 (80);
exact mass calculate for C15H16O3 (M+): 244.1099; found
244.1105.
tetralone
R4
O
HC CCO2H, HOTf
toluene, 100 °C, 6 h
R4
(1)
R3
R2
O
R3
R2
O
(2) DDQ, toluene
100 °C, 8 h
R5
R1
R5
R1
4
1
Time Yieldb
(h)a (%)
Entry
Product
1
2
3
4
5
6
7
8
9
4a R1 = R2 = R3 = R4 = R5 = H
6/8
4/6
2/4
2/4
2/4
2/4
8/10
4/6
66
75
23
20
27
17
84
43
22e
4b R5 = CH3, R1 = R2 = R3 = R4 = H
4c R1 = OCH3, R2 = R3 = R4 = R5 = H
4d R2 = OCH3, R1 = R3 = R4 = R5 = H
4e R3 = OCH3, R1 = R2 = R4 = R5 = H
4f R4 = OCH3, R1 = R2 = R3 = R5 = H
4g R2 = Br, R1 = R3 = R4 = R5 = H
4h R1 = R3 = CH3, R2 = R4 = R5 = H
4i R2 = CH3, R3 = OCH3, R1 = R4 = R5 = H 3/5
a Reaction times for the 1st and 2nd reaction steps. b Isolated yields
of the two steps.
Preparation of 4a
To a solution of 3a (142 mg, 0.634 mmol) in toluene
(6.3 mL) was sequentially added propiolic acid (0.08 mL,
2.69 mmol) and trifluoromethanesulfonic acid (TfOH, 0.04
mL, 0.507 mmol). The solution was heated to 100 °C for 2
h until the completion of reaction, monitored by TLC. The
residue was purified by flash column chromatography
(Aluminum oxide 90 active basic) with EtOAc (Rf = 0.47
for 4a, in 1:5 EtOAc-hexane) to give 4a as a pale yellow
solid (930 mg, 74% yield); mp 115-116 °C. Spectroscopic
data for 4a:1H NMR (CDCl3, 400 MHz): d 8.47 (d, J = 10.0
Hz, 1 H), 8.21 (d, J = 8.4 Hz, 1 H), 7.97 (d, J = 9.2 Hz, 1 H),
7.90 (d, J = 8.0 Hz, 1 H), 7.68 (dd, J = 8, 7.6 Hz, 1 H), 7.57
(dd, J = 7.6, 7.6 Hz, 1 H), 7.44 (d, J = 9.2 Hz, 1 H), 6.56 (d,
J = 10 Hz, 1 H); 13C NMR (CDCl3, 100 MHz): d 160.9 (C),
153.8 (C), 139.0 (CH), 133.1 (CH), 130.2 (C), 129.0 (C,
CH), 128.3 (CH), 126.0 (CH), 121.3 (CH), 117.0 (CH),
115.6 (CH), 112.9 (C); IR (neat): 2921, 2853, 1719, 1631,
1584, 1563, 1513, 1461, 1434, 1334, 1279, 1245, 1221,
1206, 1173, 1109, 1082, 897, 811, 781, 753 cm-1; EI MS
(m/z): 196 (M+, 31), 168 (72), 140 (27), 139 (100), 70 (23);
MS (m/z, relative intensity): 196 (M+, 17), 195 (11), 168
(100), 140 (19), 139 (55), 84 (11), 58 (10); exact mass cal-
culate for C13H8O2 (M+): 196.0524; found 196.0529.
Typical experimental procedure for the preparation
of coumarin 4a (2nd generation)
Completion of the synthesis of 6-hy-
droxy-7-methyl-5a,8a-benzocoumarin
(6)
Scheme III
(280 mg, 82% yield). Mp 48-50 °C. Spectroscopic data for
2a: 1H NMR (CDCl3, 400 MHz): d 7.15-7.09 (m, 3 H), 7.0
(d, J = 6.6 Hz, 1 H), 6.29 (s, 1 H), 2.99 (t, J = 8.4 Hz, 2 H),
2.57-2.53 (m, 2 H), 1.54 (s, 9 H); 13C NMR (CDCl3, 100
MHz): d 150.1 (C), 150.8 (C), 133.2 (C), 133.1 (C), 127.2
(CH), 126.8 (CH), 126.6 (CH), 126.3 (CH), 114.2 (CH),
83.3 (C), 28.6 (CH2), 27.7 (three CH3), 26.1 (CH2); IR
(neat): 3059, 2981, 2934, 1755, 1631, 1601, 1510, 1465,
1395, 1370, 1239, 1145, 958, 866, 812, 754 cm-1; MS (m/z,
relative intensity): 246 (M+, 100), 146 (91), 129 (20), 128
(11), 117 (30), 116 (11), 115 (27), 104 (25), 91 (12), 57
(100); exact mass calculate for C15H18O3 (M+): 246.1256;
found 246.1246.
Preparation of 3a
To a solution of 2a (200 mg, 0.812 mmol) in 1,4-di-
oxane (4 mL) was added 2,3-dichloro-5,6-dicyanobenzo-
quinone (DDQ, 221 mg, 1.057 mmol). The solution was
heated to 100 °C and stirred for 8 h until the completion of
A solution of b-tetralone (100 mg, 0.684 mmol),
propiolic acid (0.08 mL, 1.37 mmol), trifluoromethane-
sulfonic acid (HOTf, 0.04 mL, 0.547 mmol) in toluene (6.8
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Synthesis of Natural Occurring Juncaceae Coumarin
mL) was heated to 100 °C for 6 h until the completion of re-
action, monitored by TLC. To the solution was added 2,3-
dichloro-5,6-dicyanobenzoquinone (DDQ, 200 mg, 0.821
mmol) and the resulting solution was kept at 100 °C for ad-
ditional 8 h until the completion of reaction, monitored by
TLC. The resulting reside was purified by passing through
a chromatography, packing with aluminum oxide 90 active
basic, to give 4a as a light yellow solid (891 mg, 66%
yield).
100 MHz): d 160.8 (C), 153.5 (C), 139.3 (CH), 135.6 (C),
129.32 (C), 129.25 (C), 129.16 (CH), 128.0 (CH), 126.9
(CH), 119.5 (CH), 116.4 (CH), 115.5 (CH), 113.2 (C), 19.6
(CH3); IR (neat): 3068, 2920, 2848, 1721, 1592, 1567,
1513, 1457, 1375, 1233, 1204, 1180, 1121, 1050, 812, 795,
752 cm-1; MS (m/z, relative intensity): 210 (M+, 57), 194
(32), 182 (70), 181 (31), 153 (19), 152 (29), 151 (10), 76
(14); exact mass calculate for C14H10O2 (M+): 210.0681;
found 210.0687.
Spectroscopic data for 2b
Spectroscopic data for 2c
TLC Rf = 0.69 (Hexane/EtOAc = 10:1); colorless liq-
1
uid. Spectroscopic data for 2b: H NMR (CDCl3, 400
TLC Rf = 0.58 (Hexane/EtOAc = 10:1); pale yellow
1
liquid. Spectroscopic data for 2c: H NMR (CDCl3, 400
MHz): d 7.04 (dd, J = 7.4 Hz, 1 H), 6.98 (d, J = 7.2 Hz, 1 H),
6.87 (d, J = 7.2 Hz, 1 H), 6.27 (s, 1 H), 2.94 (t, J = 8.4 Hz, 2
H), 2.58-2.54 (m, 2 H), 2.26 (s, 3H), 1.54 (s, 9 H); 13C NMR
(CDCl3, 100 MHz): d 151.1 (C), 150.2 (C), 134.8 (C),
133.1 (C), 131.2 (C), 128.9 (CH), 126.1 (CH), 124.5 (CH),
114.4 (CH), 83.2 (C), 27.7 (three CH3), 25.7 (CH2), 24.9
(CH2), 19.5 (CH3); IR (neat): 3065, 2979, 2833, 1752,
1671, 1468, 1394, 1370, 1319, 1273, 1135, 1084, 880, 820,
779, 721 cm-1; MS (m/z, relative intensity): 260 (M+, 100),
160 (85), 145 (16), 143 (14), 131 (13), 128 (12), 115 (16),
91 (14), 57 (100); exact mass calculate for C16H20O3 (M+):
260.1412; found 260.1407.
MHz): d 7.10 (dd, J = 8.4, 7.6 Hz, 1 H), 6.73 (d, J = 8.4 Hz,
1 H), 6.66 (d, J = 7.6 Hz, 1 H), 6.26 (s, 1 H), 3.82 (s, 3 H),
2.99 (t, J = 8.4 Hz, 2 H), 2.52 (t, J = 8.4 Hz, 2 H), 1.53 (s, 9
H); 13C NMR (CDCl3, 100 MHz): d 156.2 (C), 151.0 (two
C), 134.5 (C), 127.0 (CH), 120.7 (C), 119.3 (CH), 113.9
(CH), 109.5 (CH), 83.2 (C), 55.5 (CH3), 27.7 (three CH3) ,
25.5 (CH2), 21.1 (CH2); IR (neat): 3062, 2979, 2837, 2290,
2178, 2090, 1976, 1910, 1753, 1668, 1576, 1471, 1394,
1370, 1258, 1132, 1045, 1016, 967, 885, 815, 779, 717,
644 cm-1; MS (m/z, relative intensity): 276 (M+, 87), 177
(12), 176 (96), 175 (11), 159 (23), 134 (11), 115 (13), 57
(100); exact mass calculate for C16H20O4 (M+): 276.1362;
found 276.1365.
Spectroscopic data for 3b
TLC Rf = 0.69 (Hexane/EtOAc = 10:1); pale yellow
liquid. Spectroscopic data for 3b: 1H NMR (CDCl3, 400
MHz): d 7.98 (d, J = 9.2 Hz, 1 H), 7.66-7.61 (m, 2 H), 7.37-
7.32 (m, 2 H), 7.27 (d, J = 6.8 Hz, 1 H), 2.66 (s, 3 H), 1.58
(s, 9 H); 13C NMR (CDCl3, 100 MHz): d 152.0 (C), 148.5
(C), 134.3 (C), 134.0 (C), 130.6 (C), 126.40 (CH), 126.37
(CH), 126.2 (CH), 125.7 (CH), 120.5 (CH), 118.6 (CH),
83.5 (C), 27.7 (three CH3), 19.4 (CH3); IR (neat): 3053,
2980, 2935, 2291, 2178, 2161, 2084, 1752, 1628, 1600,
1510, 1456, 1426, 1394, 1370, 1238, 1214, 1136, 1045,
1020, 980, 942, 884, 835, 819, 780, 760, 698 cm-1; MS
(m/z, relative intensity): 258 (M+, 100), 199 (19), 159 (40),
158 (100), 157 (58), 141 (20), 129 (23), 128 (31), 127 (12),
115 (12), 57 (84); exact mass calculate for C16H18O3 (M+):
258.1256; found 258.1261.
Spectroscopic data for 3c
TLC Rf = 0.58 (Hexane/EtOAc = 10:1); white solid;
mp 67-69 °C. Spectroscopic data for 3c: 1H NMR (CDCl3,
400 MHz): d 8.26 (d, J = 9.6 Hz, 1 H), 7.58 (d, J = 2.4 Hz, 1
H), 7.40-7.37 (m, 2 H), 7.37 (s, 1 H), 7.27 (dd, J = 9.6, 2.4
Hz, 1 H), 6.79-6.77 (m, 1 H), 3.98 (s, 3 H), 1.58 (s, 9 H);
13C NMR (CDCl3, 100 MHz): d 155.5 (C), 151.9 (C), 149.4
(C), 135.0 (C), 126.9 (CH), 123.8 (CH), 123.5 (C), 120.0
(CH), 119.9 (CH), 117.7 (CH), 103.7 (CH), 83.5 (C), 55.5
(CH3), 27.7 (three CH3); IR (neat): 3060, 2980, 2935, 2843,
2291, 2160, 2092, 1917, 1756, 1632, 1583, 1510, 1448,
1428, 1387, 1370, 1274, 1218, 1149, 1104, 1070, 1048,
1020, 942, 889, 871, 831, 781, 756, 724, 702 cm-1; MS
(m/z, relative intensity): 274 (M+, 100), 175 (12), 174
(100), 131 (43), 115 (31), 102 (14), 57 (16); exact mass cal-
culate for C16H18O4 (M+): 274.1205; found 274.1207.
Spectroscopic data for 4c
Spectroscopic data for 4b
TLC Rf = 0.39 (Hexane/EtOAc = 5:1); pale yellow
solid; mp 126-128 °C. Spectroscopic data for 4b: 1H NMR
(CDCl3, 400 MHz): d 8.43 (d, J = 10 Hz, 1 H), 8.13 (d, J =
9.2 Hz, 1 H), 8.05 (d, J = 8.4 Hz, 1 H), 7.55 (dd, J = 8.4, 7.2
Hz, 1 H), 7.43 (d, J = 9.2 Hz, 1 H), 7.39 (d, J = 7.2 Hz, 1 H),
6.53 (d, J = 10 Hz, 1 H), 2.71 (s, 3 H); 13C NMR (CDCl3,
TLC Rf = 0.31 (Hexane/EtOAc = 5:1); bright yellow
solid; mp 189-191 °C. Spectroscopic data for 4c: 1H NMR
(CDCl3, 400 MHz): d 8.45 (d, J = 9.2 Hz, 1 H), 8.44 (d, J =
10.0 Hz, 1 H), 7.77 (d, J = 8.0 Hz, 1 H), 7.59 (dd, J = 8.0,
8.0 Hz, 1 H), 7.41 (d, J = 9.2 Hz, 1 H), 6.91 (d, J = 8.0 Hz, 1
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H), 6.54 (d, J = 10.0 Hz, 1 H), 4.03 (s, 3H); 13C NMR
(CDCl3, 100 MHz): d 160.9 (C), 156.1 (C), 154.4 (C),
139.6 (CH), 130.4 (C), 128.8 (CH), 127.4 (CH), 122.2 (C),
115.9 (CH), 115.4 (CH), 113.4 (CH), 112.7 (C), 104.4
(CH), 55.7 (CH3); IR (neat): 2955, 2916, 2833, 1707, 1588,
1566, 1472, 1251, 1237, 1179, 1120, 1078, 1018, 910, 831,
793, 750 cm-1; MS (m/z, relative intensity): 226 (M+, 100),
198 (26), 194 (19), 182 (39), 155 (42), 139 (11), 127 (20),
126 (16), 77 (10); exact mass calculate for C14H10O3 (M+):
226.0630; found 226.0623.
H), 6.55 (d, J = 9.6 Hz, 1 H), 3.95 (s, 3H); 13C NMR
(CDCl3, 100 MHz): d 161.0 (C), 157.7 (C), 152.4 (C),
139.1 (CH), 131.8 (CH), 131.6 (C), 123.8 (C), 122.8 (CH),
120.4 (CH), 117.4 (CH), 115.8 (CH), 113.2 (C), 107.5
(CH), 55.4 (CH3); IR (neat): 2961, 2923, 2849, 1710, 1612,
1590, 1566, 1517, 1468, 1374, 1337, 1253, 1177, 1113,
1080, 1031, 989, 898, 851, 800 cm-1; MS (m/z, relative in-
tensity): 226 (M+, 100), 198 (50), 183 (43), 156 (11), 155
(98), 139 (17), 127 (60), 126 (36), 101 (12), 77 (14), 75
(12); exact mass calculate for C14H10O3 (M+): 226.0630;
found 226.0639.
Spectroscopic data for 2d
TLC Rf = 0.47 (Hexane/EtOAc = 10:1); colorless
solid; mp 88-90 °C. Spectroscopic data for 2d: 1H NMR
(CDCl3, 400 MHz): d 6.93 (d, J = 8.0 Hz, 1 H), 6.68-6.63
(m, 2 H), 6.24 (s, 1 H), 3.78 (s, 3 H), 2.96 (t, J = 8.4 Hz, 2
H), 2.52 (t, J = 8.0 Hz, 2 H), 1.53 (s, 9 H); 13C NMR
(CDCl3, 100 MHz): d 158.6 (C), 151.3 (C), 148.7 (C),
134.8 (C), 127.2 (CH), 126.0 (C), 113.7 (two CH), 111.2
(CH), 83.2 (C), 55.3 (CH3), 29.1 (CH2), 27.7 (three CH3),
25.9 (CH2); IR (neat): 2976, 2937, 2837, 1749, 1664, 1609,
1576, 1498, 1461, 1427, 1369, 1274, 1244, 1162, 1134,
1113, 1038, 886 cm-1; MS (m/z, relative intensity): 276
(M+, 41), 177 (12), 176 (100), 161 (22), 159 (17), 147 (18),
57 (77); exact mass calculate for C16H20O4 (M+): 276.1362;
found 276.1363.
Spectroscopic data for 2e
TLC Rf = 0.47 (Hexane/EtOAc = 10:1); white solid;
mp 46-48 °C. Spectroscopic data for 2e: 1H NMR (CDCl3,
400 MHz): d 7.01 (d, J = 8.4 Hz, 1 H), 6.65 (dd, J = 8.4, 2.4
Hz, 1 H), 6.59 (d, J = 2.4 Hz, 1 H), 6.26 (s, 1 H), 3.77 (s,
3H), 2.92 (t, J = 8.4 Hz, 2 H), 2.55-2.51 (m, 2 H), 1.54 (s, 9
H); 13C NMR (CDCl3, 100 MHz): d 158.4 (C), 151.5 (C),
151.0 (C), 134.3 (C), 127.9 (CH), 125.2 (C), 114.2 (CH),
112.1 (CH), 111.7 (CH), 83.3 (C), 55.3 (CH3), 27.74 (CH2),
27.67 (three CH3), 26.4 (CH2); IR (neat): 2980, 2937, 2834,
1752, 1665, 1607, 1575, 1499, 1463, 1423, 1394, 1370,
1311, 1248, 1215, 1132, 1039, 888, 809, 784, 732 cm-1; MS
(m/z, relative intensity): 276 (M+, 62), 176 (37), 159 (11),
134 (10), 115 (10), 57 (100); exact mass calculate for
C16H20O4 (M+): 276.1362; found 276.1367.
Spectroscopic data for 3d
TLC Rf = 0.47 (Hexane/EtOAc = 10:1); white solid;
1
mp 135-137 °C. Spectroscopic data for 3d: H NMR
Spectroscopic data for 3e
TLC Rf = 0.47 (Hexane/EtOAc = 10:1); white solid;
mp 74-76 °C. Spectroscopic data for 3e: 1H NMR (CDCl3,
400 MHz): d 7.75 (d, J = 8.8 Hz, 1 H), 7.71 (d, J = 8.8 Hz, 1
H), 7.53 (d, J = 2.0 Hz, 1 H), 7.15 (dd, J = 8.8, 2.0 Hz, 1 H),
7.12-7.09 (m, 2H), 3.90 (s, 3 H), 1.58 (s, 9 H); 13C NMR
(CDCl3, 100 MHz): d 158.2 (C), 152.0 (C), 149.3 (C),
135.1 (C), 129.2 (CH), 129.1 (CH), 126.8 (C), 118.6 (CH),
118.3 (CH), 117.2 (CH), 105.6 (CH), 83.6 (C), 55.3 (CH3),
27.7 (three CH3); IR (neat): 3063, 2980, 2937, 1755, 1634,
1609, 1513, 1467, 1427, 1391, 1371, 1276, 1245, 1216,
1145, 1031, 955, 892, 835, 811, 781, 751 cm-1; MS (m/z,
relative intensity): 274 (M+, 100), 175 (12), 174 (100), 157
(11), 145 (24), 131 (27), 102 (25), 57 (47); exact mass cal-
culate for C16H18O4 (M+): 274.1205; found 274.1204.
Spectroscopic data for 4e
(CDCl3, 400 MHz): d 7.72 (d, J = 8.8 Hz, 1 H), 7.69 (d, J =
8.8 Hz, 1 H), 7.55 (d, J = 2.0 Hz, 1 H), 7.28 (d, J = 2.0 Hz, 1
H), 7.17-7.14 (m, 2H), 3.91 (s, 3 H), 1.54 (s, 9 H); 13C NMR
(CDCl3, 100 MHz): d 157.7 (C), 152.2 (C), 147.1 (C),
132.5 (C), 129.1 (CH), 129.0 (C), 128.0 (CH), 121.2 (CH),
119.4 (CH), 118.1 (CH), 105.8 (CH), 83.5 (C), 55.3 (CH3),
27.7 (three CH3); IR (neat): 3002, 2970, 2938, 1752, 1708,
1633, 1606, 1509, 1482, 1456, 1390, 1370, 1336, 1287,
1262, 1226, 1166, 1150, 1048, 1025, 965, 937, 896, 856,
820, 810, 780, 743 cm-1; MS (m/z, relative intensity): 274
(M+, 63), 175 (11), 174 (100), 159 (35), 145 (14), 131 (67),
103 (13), 102 (33), 77 (14), 57 (40); exact mass calculate
for C16H18O4 (M+): 274.1205; found 274.1204.
Spectroscopic data for 4d
TLC Rf = 0.23 (Hexane/EtOAc = 5:1); pale yellow
solid; mp 167-169 °C. Spectroscopic data for 4d: 1H NMR
(CDCl3, 400 MHz): d 8.40 (d, J = 9.6 Hz, 1 H), 8.10 (d, J =
9.2 Hz, 1 H), 7.87 (d, J = 9.2 Hz, 1 H), 7.42 (d, J = 9.2 Hz, 1
H), 7.33 (dd, J = 9.2 Hz, 2.4 Hz, 1 H), 7.21 (d, J = 2.4 Hz, 1
TLC Rf = 0.22 (Hexane/EtOAc = 5:1); white solid;
1
mp 168-170 °C. Spectroscopic data for 4e: H NMR
(CDCl3, 400 MHz): d 8.42 (d, J = 9.6 Hz, 1 H), 7.89 (d, J =
8.8 Hz, 1 H), 7.82 (d, J = 8.8 Hz, 1 H), 7.49 (d, J = 2.4 Hz, 1
H), 7.32 (d, J = 8.8 Hz, 1 H), 7.21 (dd, J = 8.8, 2.4 Hz, 1 H),
412
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J. Chin. Chem. Soc. 2012, 59, 407-420

JOURNAL OF THE CHINESE
CHEMICAL SOCIETY
Synthesis of Natural Occurring Juncaceae Coumarin
6.54 (d, J = 9.6 Hz, 1 H), 4.00 (s, 3 H); 13C NMR (CDCl3,
100 MHz): d 161.0 (C), 159.7 (C), 154.6 (C), 139.2 (CH),
132.9 (CH), 130.7 (C), 130.6 (CH), 125.5 (C), 117.6 (CH),
114.9 (CH), 114.5 (CH), 112.2 (C), 101.2 (CH), 55.5
(CH3); IR (neat): 2994, 2961, 2920, 2851, 1731, 1706,
1631, 1571, 1513, 1459, 1376, 1286, 1247, 1227, 1172,
1114, 1030, 910, 824 cm-1; ESI MS (m/z): 249 (M+, +23) ;
MS (m/z, relative intensity): 226 (M+, 49), 198 (48), 195
(27), 183 (15), 155 (31), 139 (10), 127 (19), 121 (66), 117
(38), 111 (10), 99 (13), 97 (17), 91 (57), 85 (24), 83 (17), 71
(32), 69 (17), 57 (45), 55 (17); exact mass calculate for
C14H10O3 (M+): 226.0630; found 226.0636.
8.8 Hz, 1 H), 7.49 -7.43 (m, 2 H), 7.41 (d, J = 8.8 Hz, 1 H),
7.07 (dd, J = 6.4, 2.4 Hz, 1 H), 6.45 (d, J = 10.0 Hz, 1 H),
4.06 (s, 3 H); 13C NMR (CDCl3, 100 MHz): d 160.7 (C),
157.1 (C), 154.6 (C), 144.7 (CH), 133.2 (CH), 132.4 (C),
126.0 (CH), 121.8 (CH), 120.1 (C), 117.7 (CH), 114.1
(CH), 113.6 (C), 108.5 (CH), 55.6 (CH3); IR (neat): 3066,
2922, 2838, 1731, 1606, 1557, 1514, 1462, 1441, 1353,
1330, 1268, 1255, 1214, 1175, 1113, 1062, 985, 904, 828,
794, 756, 722 cm-1; MS (m/z, relative intensity): 226 (M+,
100), 199 (10), 198 (70), 183 (58), 167 (35), 155 (66), 139
(19), 127 (29), 126 (16), 75 (12), 63 (11); exact mass calcu-
late for C14H10O3 (M+): 226.0630; found 226.0638.
Spectroscopic data for 2g
Spectroscopic data for 2f
TLC Rf = 0.53 (Hexane/EtOAc = 10:1); white solid;
mp 48-50 °C. Spectroscopic data for 2f: 1H NMR (CDCl3,
400 MHz): d 7.07 (t, J = 8.0 Hz, 1 H), 6.73 (d, J = 8.0 Hz, 1
H), 6.70 (d, J = 8.0 Hz, 1 H), 6.66 (s, 1 H), 3.80 (s, 3 H),
2.96 (t, J = 8.0 Hz, 2 H), 2.54-2.49 (m, 2 H), 1.53 (s, 9 H);
13C NMR (CDCl3, 100 MHz): d 154.8 (C), 151.2 (C), 149.9
(C), 134.5 (C), 127.2 (CH), 121.9 (C), 119.8 (CH), 108.9
(CH), 108.5 (CH), 83.1 (C), 55.5 (CH3), 29.0 (CH2), 27.7
(three CH3), 25.8 (CH2); IR (neat): 3072, 2980, 2935, 2836,
1752, 1663, 1578, 1472, 1439, 1370, 1323, 1252, 1212,
1139, 1086, 893, 859, 780, 739, 702, 651 cm-1; MS (m/z,
relative intensity): 276 (M+, 18), 177 (12), 176 (100), 161
(18), 159 (17), 115 (11), 57 (80); exact mass calculate for
C16H20O4 (M+): 276.1362; found 276.1366.
TLC Rf = 0.62 (Hexane/EtOAc = 5:1); white solid;
mp 87-89 °C. Spectroscopic data for 2g: 1H NMR (CDCl3,
400 MHz): d 7.21 (dd, J = 8.0, 2.0 Hz, 1 H), 7.14 (d, J = 2.0
Hz, 1 H), 6.96 (d, J = 8.0 Hz, 1 H), 6.23 (s, 1 H), 2.92 (t, J =
8.0 Hz, 2 H), 2.54 (t, J = 8.0 Hz, 2 H), 1.55 (s, 9 H); 13
C
NMR (CDCl3, 100 MHz): d 151.9 (C), 150.9 (C), 135.4(C),
131.9(C), 129.4 (CH), 128.9 (CH), 128.7 (CH), 120.1 (C),
113.2 (CH), 83.6 (C), 28.1 (CH2), 27.7 (three CH3), 25.9
(CH2); IR (neat): 2980, 2937, 1753, 1666, 1591, 1482,
1395, 1370, 1300, 1274, 1255, 1233, 1133, 1076, 888, 813,
782, 673 cm-1; MS (m/z, relative intensity): 324 (M+, 100),
226 (31), 224 (33), 209 (9), 207 (9), 139 (10), 116 (18), 115
(19), 57 (100); exact mass calculate for C15H17BrO3 (M+):
324.0361; found 324.0364.
Spectroscopic data for 3f
Spectroscopic data for 3g
TLC Rf = 0.53 (Hexane/EtOAc = 10:1); white solid;
mp 85-87 °C. Spectroscopic data for 3f: 1H NMR (CDCl3,
400 MHz): d 8.03 (d, J = 2.4 Hz, 1 H), 7.79 (d, J = 8.8 Hz, 1
H), 7.41 (d, J = 8.0 Hz, 1 H), 7.36 (t, J = 8.0 Hz, 1 H), 7.30
(dd, J = 8.8, 2.4 Hz, 1 H), 6.82 (d, J = 8.0 Hz, 1 H), 3.99 (s,
3 H), 1.58 (s, 9 H); 13C NMR (CDCl3, 100 MHz): d 155.2
(C), 152.1 (C), 148.4 (C), 132.4 (C), 128.9 (CH), 125.9
(C), 125.7 (CH), 121.3 (CH), 119.9 (CH), 113.1 (CH),
104.3 (CH), 83.5 (C), 55.4 (CH3), 27.7 (three CH3); IR
(neat): 3064, 2980, 2934, 1757, 1601, 1585, 1510, 1465,
1437, 1371, 1272, 1235, 1215, 1201, 1149, 1100, 1066,
997, 887, 864, 826, 781, 747 cm-1; MS (m/z, relative inten-
sity): 274 (M+, 100), 175 (13), 174 (100), 159 (38), 131
(11), 115 (26), 102 (15), 57 (56); exact mass calculate for
C16H18O4 (M+): 274.1205; found 274.1211.
TLC Rf = 0.62 (Hexane/EtOAc = 5:1); white solid;
1
mp 110-112 °C. Spectroscopic data for 3g: H NMR
(CDCl3, 400 MHz): d 7.94 (s, 1 H), 7.78 (d, J = 8.8 Hz, 1
H), 7.66 (d, J = 8.8 Hz, 1 H), 7.54 (s, 1 H), 7.50 (d, J = 8.8
Hz, 1 H), 7.31 (d, J = 8.8 Hz, 1 H), 1.55 (s, 9 H); 13C NMR
(CDCl3, 100 MHz): d 151.7 (C), 149.4 (C), 134.8 (C),
129.7 (C), 129.6 (CH), 129.3 (CH), 129.2 (CH), 129.1
(CH), 121.3 (CH), 120.7 (C), 117.3 (CH), 83.8 (C), 27.7
(three CH3); IR (neat): 3003, 2980, 2923, 1753, 1626,
1577, 1503, 1450, 1369, 1321, 1280, 1258, 1234, 1201,
1150, 1062, 959, 921, 903, 842, 781, 717 cm-1; MS (m/z,
relative intensity): 322 (M+, 35), 224 (55), 222 (49), 207
(4), 205 (4), 195 (7), 193 (8), 143 (7), 141 (5), 139 (13),
126 (11), 114 (17), 57 (100); exact mass calculate for
C15H15BrO3 (M+): 322.0205; found 322.0206.
Spectroscopic data for 4f
Spectroscopic data for 4g
TLC Rf = 0.22 (Hexane/EtOAc = 5:1); yellow solid;
1
mp 122-124 °C. Spectroscopic data for 4f: H NMR
TLC Rf = 0.33 (Hexane/EtOAc = 5:1); pale orange
solid; mp 174-176 °C. Spectroscopic data for 4g: 1H NMR
(CDCl3, 400 MHz):1H NMR (CDCl3, 400 MHz): d 8.36 (d,
(CDCl3, 400 MHz): d 9.45 (d, J = 10.0 Hz, 1 H), 7.89 (d, J =
J. Chin. Chem. Soc. 2012, 59, 407-420
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413

Article
Hon et al.
1
J = 9.6 Hz, 1 H), 8.33 (s, 1 H), 7.92 (d, J = 8.8 Hz, 1 H), 7.76
(d, J = 8.8 Hz, 1 H), 7.63 (dd, J = 8.8, 1.6 Hz, 1 H), 7.45 (d,
J = 8.8 Hz, 1 H), 6.58 (d, J = 9.6 Hz, 1 H); 13C NMR
(CDCl3, 100 MHz): d 160.3 (C), 154.2 (C), 138.5 (CH),
132.7 (CH), 130.4 (CH), 130.1 (C), 129.4 (CH), 128.6 (C),
124.0 (CH), 122.9 (C), 117.4 (CH), 116.0 (CH), 112.1 (C);
IR (neat): 3076, 2922, 2852, 1725, 1627, 1583, 1563, 1498,
1451, 1321, 1245, 1202, 1174, 1113, 1086, 898, 828, 772,
715 cm-1; MS (m/z, relative intensity): 276 (M++3, 70), 274
(M++1, 71), 273 (M+, 100), 249 (10), 248 (81), 247 (10),
246 (82), 195 (24), 167 (26), 140 (11), 139 (100), 138 (20),
137 (11), 113 (10), 87 (11), 69 (36), 63 (13); exact mass cal-
culate forC13H7BrO2 (M+): 273.9629; found 273.9637.
Spectroscopic data for 2h
mp 193-195 °C. Spectroscopic data for 4h: H NMR
(CDCl3, 400 MHz): d 8.46 (d, J = 10.0 Hz, 1 H), 8.09 (d, J =
9.20 Hz, 1 H), 7.84 (s, 1 H), 7.38 (d, J = 9.20 Hz, 1 H), 7.24
(s, 1 H), 6.52 (d, J = 10.0 Hz, 1 H), 2.68 (s, 3 H), 2.54 (s, 3
H); 13C NMR (CDCl3, 100 MHz): d 160.9 (C), 153.7 (C),
139.4 (CH), 137.9 (C), 135.2 (C), 129.5 (C), 129.0 (CH),
128.9 (CH), 127.5 (C), 118.8 (CH), 115.4 (CH), 115.1
(CH), 112.7 (C), 22.0 (CH3), 19.4 (CH3); IR (neat): 3046,
2917, 2853, 1708, 1625, 1566, 1507, 1443, 1375, 1323,
1261, 1212, 1176, 1120, 1072, 909, 827, 780 cm-1; MS
(m/z, relative intensity): 224 (M+, 100), 209 (47), 196 (41),
181 (19), 165 (14), 152 (24); exact mass calculate for
C15H12O2 (M+): 224.0837; found 224.0831.
Spectroscopic data for 2i
TLC Rf = 0.69 (Hexane/EtOAc = 10:1); white solid;
mp 41-43 °C. Spectroscopic data for 2h: 1H NMR (CDCl3,
400 MHz): d 6.82 (s, 1 H), 6.70 (s, 1 H), 6.23 (s, 1 H), 2.90
(t, J = 8.4 Hz, 2 H), 2.57-2.52 (m, 2 H), 2.25 (s, 3 H), 2.23
(s, 3 H), 1.56 (s, 9 H); 13C NMR (CDCl3, 100 MHz): d
151.1 (C), 150.3 (C), 135.5 (C), 134.7 (C), 133.1 (C), 129.6
(CH), 128.2 (C), 125.3 (CH), 114.4 (CH), 83.2 (C), 27.7
(three CH3), 25.9 (CH2), 24.6 (CH2), 20.8 (CH3), 19.4
(CH3); IR (neat): 3006, 2979, 2834, 1752, 1671, 1607,
1577, 1478, 1394, 1370, 1329, 1273, 1134, 1058, 1011,
990, 880, 808, 784, 737, 697 cm-1; MS (m/z, relative inten-
sity): 274 (M+, 72), 174 (81), 159 (18), 157 (21), 145 (20),
132 (11), 130 (13), 129 (16), 128 (13), 115 (15), 57 (100);
exact mass calculate for C17H22O3 (M+): 274.1569; found
274.1559.
TLC Rf = 0.68 (Hexane/EtOAc = 5:1); white solid;
mp 66-68 °C. Spectroscopic data for 2i: 1H NMR (CDCl3,
400 MHz): d 6.87 (s, 1 H), 6.51 (s, 1 H), 6.25 (s, 1 H), 3.79
(s, 3 H), 2.89 (t, J = 8.0 Hz, 2 H), 2.51 (t, J = 8.0 Hz, 2 H),
2.17 (s, 3H), 1.53 (s, 9H); 13C NMR (CDCl3, 100 MHz): d
156.3 (C), 151.1 (C), 150.4 (C), 131.6 (C), 129.6 (CH),
124.7 (C), 124.6 (C), 114.1 (CH), 108.6 (CH), 83.2 (C),
55.5 (CH3), 27.8 (CH2), 27.7 (three CH3), 26.5 (CH2), 15.9
(CH3); IR (neat): 2980, 2937, 2833, 1752, 1665, 1614,
1572, 1506, 1464, 1395, 1370, 1248, 1211, 1162, 1133,
1070, 1032, 889, 838, 783, 752, 704 cm-1; MS (m/z, relative
intensity): 290 (M+,18), 191 (13), 190 (100), 189 (11), 173
(17), 148 (11), 57 (74); exact mass calculate for C17H22O4
(M+): 290.1518; found 290.1513.
Spectroscopic data for 3i
Spectroscopic data for 3h
TLC Rf = 0.68 (Hexane/EtOAc = 5:1); pale yellow
liquid. Spectroscopic data for 3di: 1H NMR (CDCl3, 400
MHz): d 7.68 (d, J = 8.8 Hz, 1 H), 7.55 (s, 1 H), 7.50 (d, J =
2.4 Hz, 1 H), 7.12 (dd, J = 8.8, 2.4 Hz, 1 H), 7.03 (s, 1 H),
3.92 (s, 3 H), 2.35 (s, 3 H), 1.58 (s, 9 H); 13C NMR (CDCl3,
100 MHz): d 157.4 (C), 152.1 (C), 148.6 (C), 133.8 (C),
128.5 (CH), 128.3 (C), 128.2 (CH), 126.7 (C), 118.1 (CH),
116.8 (CH), 104.3 (CH), 83.4 (C), 55.3 (CH3), 27.7 (three
CH3), 16.8 (CH3); IR (neat): 2977, 2955, 2924, 1754, 1637,
1509, 1462, 1415, 1370, 1279, 1242, 1141, 894, 804, 750
cm-1; MS (m/z, relative intensity): 288 (M+, 20), 189 (12),
188 (100), 149 (13), 145 (18), 115 (11), 57 (44); exact mass
calculate for C17H20O4 (M+): 288.1362; found 288.1367.
Spectroscopic data for 4i
TLC Rf = 0.69 (Hexane/EtOAc = 10:1); white solid;
mp 58-60 °C. Spectroscopic data for 3h: 1H NMR (CDCl3,
400 MHz): d 7.93 (d, J = 9.0 Hz, 1 H), 7.53 (d, J = 2.4 Hz, 1
H), 7.43 (s, 1 H), 7.26 (dd, J = 9.2, 2.4 Hz, 1 H), 7.13 (s, 1
H), 2.64 (s, 3 H), 2.45 (s, 3 H), 1.58 (s, 9 H); 13C NMR
(CDCl3, 100 MHz): d 152.0 (C), 148.6 (C), 136.1 (C),
134.3 (C), 134.0 (C), 128.9 (C), 128.8 (CH), 125.5 (CH),
125.1 (CH), 119.5 (CH), 118.0 (CH), 83.5 (C), 27.7 (three
CH3), 21.6 (CH3), 19.3 (CH3); IR (neat): 2979, 2936, 1752,
1633, 1611, 1584, 1511, 1455, 1418, 1394, 1370, 1256,
1218, 1147, 1045, 1020, 993, 936, 883, 843, 817, 804, 781,
758, 705 cm-1; MS (m/z, relative intensity): 272 (M+, 23),
173 (14), 172 (100), 171 (10), 157 (18), 143 (19), 128 (27),
115 (11), 57 (21); exact mass calculate for C17H20O3 (M+):
272.1412; found 272.1409.
TLC Rf = 0.34 (Hexane/EtOAc = 3:1); yellow solid;
mp 193-195 °C. Spectroscopic data for 4i: 1H NMR (CDCl3,
400 MHz): d 8.38 (d, J = 9.6 Hz, 1 H), 7.79 (d, J = 8.8 Hz, 1
H), 7.59 (s, 1 H), 7.35 (s, 1 H), 7.25 (d, J = 8.8 Hz, 1 H),
Spectroscopic data for 4h
TLC Rf = 0.29 (Hexane/EtOAc = 5:1); yellow solid;
414
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© 2012 The Chemical Society Located in Taipei & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
J. Chin. Chem. Soc. 2012, 59, 407-420

JOURNAL OF THE CHINESE
CHEMICAL SOCIETY
Synthesis of Natural Occurring Juncaceae Coumarin
6.50 (d, J = 9.6 Hz, 1 H), 4.00 (s, 3 H), 2.37 (s, 3 H); 13
C
(C), 115.0 (CH), 114.7 (CH), 112.2 (C), 107.5 (CH), 100.8
(CH), 55.94 (CH3) , 55.89 (CH3); IR (neat): 3004, 2928,
2851, 1729, 1629, 1593, 1570, 1517, 1485, 1434, 1271,
1232, 1163, 1122, 1020, 906, 853, 827, 806 cm-1; MS (m/z,
relative intensity): 256 (M+, 18), 228 (17), 225 (15), 213
(17), 185 (18), 183 (12), 170 (22), 157 (17), 155 (14), 142
(39), 139 (13), 127 (11), 126 (11), 114 (23), 113 (13); exact
mass calculate for C15H12O4 (M+): 256.0736; found
256.0731.
NMR (CDCl3, 100 MHz): d 161.1 (C), 158.8 (C), 153.8
(C), 139.2 (CH), 132.1 (CH), 129.9 (CH), 129.2 (C), 128.4
(C), 125.3 (C), 114.7 (CH), 114.1 (CH), 112.1 (C), 98.9
(CH), 55.4 (CH3), 16.5 (CH3); IR (neat): 2996, 2921, 2850,
1729, 1711, 1635, 1571, 1509, 1467, 1320, 1253, 1225,
1148, 1118, 1025, 827 cm-1; MS (m/z, relative intensity):
240 (M+,100), 212 (54), 209 (27), 197 (28), 169 (36), 152
(10), 141 (14), 139 (18), 115 (19), 113 (14); exact mass cal-
culate for C15H12O3 (M+): 240.0786; found 240.0790.
Spectroscopic data for 2j
Spectroscopic data for 2k
TLC Rf = 0.47 (Hexane/EtOAc = 10:1); colorless liq-
1
uid. Spectroscopic data for 2k: H NMR (CDCl3, 400
TLC Rf = 0.31 (Hexane/EtOAc = 5:1); yellow solid;
mp 92-96 °C. Spectroscopic data for 2j: 1H NMR (CDCl3,
400 MHz): d 6.67 (s, 1 H), 6.57 (s, 1 H), 6.21 (s, 1 H), 3.86
(s, 3 H), 3.84 (s, 3 H), 2.92 (t, J = 8.4 Hz, 2 H), 2.52 (t, J =
8.4 Hz, 2 H), 1.53 (s, 9 H); 13C NMR (CDCl3, 100 MHz): d
151.2 (C), 149.2 (C), 147.6 (C), 147.4 (C), 125.7 (CH),
125.4 (C), 113.7 (CH), 111.2 (CH), 110.1 (CH), 83.2 (C),
56.0 (two CH3), 28.4 (CH2), 27.7 (three CH3), 26.1 (CH2);
IR (neat): 2977, 2936, 2833, 1751, 1666, 1606, 1516, 1463,
1370, 1322, 1270, 1247, 1213, 1160, 1132, 1026, 980, 889,
784, 753 cm-1; MS (m/z, relative intensity): 306 (M+, 100),
206 (35), 57 (100); exact mass calculate for C17H22O5 (M+):
306.1467; found 306.1469.
MHz): d 6.67-6.63 (m, 2 H), 6.63 (s, 1 H), 3.78 (s, 3 H),
3.76 (s, 3 H), 2.97 (t, J = 8.8 Hz, 2 H), 2.49 (t, J = 8.8 Hz, 2
H), 1.53 (s, 9 H); 13C NMR (CDCl3, 100 MHz): d 151.1 (C),
150.5 (C), 150.4 (C), 149.4 (C), 123.3 (C), 122.4 (C), 109.7
(CH), 109.1 (CH), 108.4 (CH), 83.1 (C), 56.1 (CH3), 55.9
(CH3), 27.7 (three CH3), 25.2 (CH2) , 21.7 (CH2); IR (neat):
2978, 2937, 2832, 1752, 1483, 1370, 1278, 1256, 1138,
1082, 953, 858, 787, 717 cm-1; MS (m/z, relative intensity):
306 (M+, 81), 207 (17), 206 (100), 191 (50), 189 (20), 57
(65); exact mass calculate for C17H20O5 (M+): 306.1467;
found 306.1470.
Spectroscopic data for 3k
TLC Rf = 0.47 (Hexane/EtOAc = 10:1); colorless liq-
1
uid. Spectroscopic data for 3k: H NMR (CDCl3, 400
Spectroscopic data for 3j
TLC Rf = 0.31 (Hexane/EtOAc = 5:1); white solid;
1
mp 108-110 °C. Spectroscopic data for 3j: H NMR
MHz): d 8.21 (d, J = 9.2 Hz, 1 H), 7.98 (d, J = 2.4 Hz, 1 H),
7.31 (dd, J = 9.2, 2.4 Hz, 1 H), 6.66 (d, J = 8.4 Hz, 1 H),
6.61 (d, J = 8.4 Hz, 1 H), 3.90 (s, 3 H), 3.89 (s, 3 H), 1.56 (s,
9 H); 13C NMR (CDCl3, 100 MHz): d 151.9 (C), 149.4 (C),
149.1 (two C), 126.9 (C), 124.2 (C), 123.6 (CH), 120.4
(CH), 112.8 (CH), 104.0 (CH), 103.0 (CH), 83.3 (C), 55.6
(two CH3), 27.7 (three CH3); IR (neat): 3080, 2980, 2937,
2836, 1757, 1633, 1601, 1464, 1426, 1395, 1362, 1269,
1238, 1148, 1099, 1004, 970, 886, 862, 804, 719 cm-1; MS
(m/z, relative intensity): 304 (M+, 32), 205 (12), 204 (89),
189 (100), 175 (10), 146 (11), 57 (35); exact mass calculate
for C17H20O5 (M+): 304.1311; found 304.1309.
(CDCl3, 400 MHz): d 7.65 (d, J = 8.8 Hz, 1 H), 7.48 (d, J =
2.4 Hz, 1 H), 7.15 (dd, J = 8.8, 2.4 Hz, 1 H), 7.07 (s, 1 H),
7.04 (s, 1 H), 3.96 (s, 3 H), 3.95 (s, 3H), 1.57 (s, 9 H); 13
C
NMR (CDCl3, 100 MHz): d 152.1 (C), 150.0 (C), 149.2
(C), 147.6 (C), 129.4 (C), 127.4 (CH), 126.9 (C), 118.6
(CH), 116.8 (CH), 106.1 (CH), 106.0 (CH), 83.2 (C), 55.7
(two CH3), 27.6 (three CH3); IR (neat): 3004, 2978, 2936,
1753, 1632, 1609, 1512, 1492, 1463, 1421, 1370, 1278,
1244, 1214, 1144, 1007, 895, 850, 811, 781, 751 cm-1; MS
(m/z, relative intensity): 304 (M+, 51), 204 (57), 57 (100);
exact mass calculate for C17H20O5 (M+): 304.1311; found
304.1317.
Spectroscopic data for 4k
TLC Rf = 0.19 (Hexane/EtOAc = 5:1); yellow solid;
mp 172-173 °C. Spectroscopic data for 4k: 1H NMR (CDCl3,
400 MHz): d 9.53 (d, J = 10.0 Hz, 1 H), 8.47 (d, J = 9.2 Hz,
1 H), 7.44 (d, J = 9.2 Hz, 1 H), 7.00 (d, J = 8.4 Hz, 1 H),
6.82 (d, J = 8.4 Hz, 1 H), 6.46 (d, J = 10.0 Hz, 1 H), 4.01 (s,
3 H), 3.98 (s, 3 H); 13C NMR (CDCl3, 100 MHz): d 160.8
(C), 155.2 (C), 151.0 (C), 150.0 (C), 144.9 (CH), 127.3
(CH), 123.7 (C), 121.2 (C), 116.9 (CH), 114.1 (CH), 113.5
Spectroscopic data for 4j
TLC Rf = 0.18 (Hexane/EtOAc = 3:1); brown solid;
1
mp 194-196 °C. Spectroscopic data for 4j: H NMR
(CDCl3, 400 MHz): d 8.36 (d, J = 10.0 Hz, 1 H), 7.79 (d, J =
8.4 Hz, 1 H), 7.42 (s, 1 H), 7.28 (d, J = 8.4 Hz, 1 H), 7.16 (s,
1 H), 6.51 (d, J = 10.0 Hz, 1 H), 4.07 (s, 3 H), 4.01 (s, 3 H);
13C NMR (CDCl3, 100 MHz): d 161.0 (C), 152.8 (C), 151.2
(C), 149.1 (C), 139.1 (CH), 131.3 (CH), 125.7 (C), 124.6
J. Chin. Chem. Soc. 2012, 59, 407-420
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(C), 108.6 (CH), 104.1 (CH), 55.92 (CH3), 55.86 (CH3); IR
(neat): 2917, 2849, 1725, 1598, 1559, 1462, 1417, 1336,
1243, 1214, 1181, 1109, 1057, 1010, 823, 786 cm-1; MS
(m/z, relative intensity): 256 (M+, 16), 241 (13), 240 (91),
213 (31), 197 (16), 169 (13); exact mass calculate for
C15H12O4 (M+): 256.0736; found 256.0729.
1378, 1359, 1224, 1167, 1125, 1009, 896, 825, 756 cm-1;
MS (m/z, relative intensity): 210 (M+, 100), 195 (36), 183
(14), 182 (100), 181 (55), 165 (10), 154 (13), 153 (39), 152
(59), 151 (19), 139 (15), 127 (21), 115 (12), 76 (20), 63
(10); exact mass calculate for C14H10O2 (M+): 210.0681;
found 210.0688.
Spectroscopic data for 2l
Spectroscopic data for 2m
TLC Rf = 0.76 (Hexane/EtOAc = 10:1); pale yellow
1
liquid. Spectroscopic data for 2l: H NMR (CDCl3, 400
TLC Rf = 0.61 (Hexane/EtOAc = 10:1); pale yellow
liquid. Spectroscopic data for 2m: 1H NMR (CDCl3, 400
MHz): d 7.34-7.30 (m, 2 H), 7.26-7.24 (m, 3 H), 7.15 (t, J =
7.6 Hz, 1 H), 7.09-7.03 (m, 1 H), 6.76 (d, J = 7.6 Hz, 1 H),
6.38 (s, 1 H), 4.33 (t, J = 9.2 Hz, 1 H), 2.86-2.84 (m, 2 H),
1.51 (s, 9 H); 13C NMR (CDCl3, 100 MHz): d 150.9 (C),
149.4 (C), 143.4 (C), 135.9 (C), 133.2 (C), 128.6 (CH),
128.4 (CH), 127.5 (CH), 127.1 (CH), 126.9 (CH), 126.8
(CH), 126.5 (CH), 114.1 (CH), 83.3 (C), 45.3 (CH), 34.4
(CH2), 27.4 (three CH3); IR (neat): 3022, 2980, 2934, 1752,
1667, 1485, 1452, 1370, 1281, 1245, 1161, 1133, 753, 700
cm-1; MS (m/z, relative intensity): 322 (M+, 9), 223 (18),
222 (100), 220 (13), 205 (20), 179 (28), 178 (15), 57 (81);
exact mass calculate for C21H22O3 (M+): 322.1569; found
322.1560.
MHz): d 7.15-7.12 (m, 3 H), 7.04-7.00 (m, 1 H), 6.28 (s, 1
H), 3.16-3.10 (m, 1 H), 2.77-2.71 (m, 1 H), 2.29 (dd, J =
16.8, 6.8 Hz, 1 H), 1.53 (s, 9 H), 1.30 (d, J = 6.8 Hz, 3 H);
13C NMR (CDCl3, 100 MHz): d 151.1 (C), 149.5 (C), 146.8
(C), 138.3 (C), 132.4 (C), 127.1 (CH), 126.6 (CH), 125.9
(CH), 113.6 (CH), 83.2 (C), 33.7 (CH2), 33.5 (CH), 27.7
(three CH3), 20.5 (CH2); IR (neat): 3068, 2978, 2929, 1753,
1669, 1455, 1395, 1370, 1273, 1252, 1165, 1136, 1073,
846, 753 cm-1; MS (m/z, relative intensity): 260 (M+, 80),
161 (10), 160 (100), 145 (56), 143 (28), 128 (14), 115 (19),
91 (13); exact mass calculate for C16H20O3 (M+): 260.1412;
found 260.1410.
Spectroscopic data for 3l
TLC Rf = 0.76 (Hexane/EtOAc = 10:1); pale yellow
1
liquid. Spectroscopic data for 3l: H NMR (CDCl3, 400
Spectroscopic data for 3m
TLC Rf = 0.61 (Hexane/EtOAc = 10:1); orange solid;
mp 76-78 °C. Spectroscopic data for 3m: 1H NMR (CDCl3,
400 MHz): d 7.86 (d, J = 6.4 Hz, 1 H), 7.84 (d, J = 6.4 Hz, 1
H), 7.65 (s, 1 H), 7.48-7.35 (m, 7 H), 7.28 (d, J = 2.4 Hz, 1
H), 1.57 (s, 9 H); 13C NMR (CDCl3, 100 MHz): d 151.9 (C),
148.1 (C), 142.0 (C), 139.7 (C), 134.3 (C), 130.0 (two
CH2), 129.7 (C), 128.3 (two CH), 128.1 (CH), 127.6 (CH),
126.5 (CH), 126.0 (CH), 125.8 (CH), 121.7 (CH), 117.6
(CH), 83.6 (C), 27.7 (three CH3); IR (neat): 3058, 2980,
2932, 1757, 1624, 1596, 1493, 1454, 1424, 1393, 1370,
1344, 1296, 1251, 1209, 1145, 1073, 1030, 981, 921, 882,
862, 783, 756, 734, 701 cm-1; MS (m/z, relative intensity):
320 (M+, 21), 221 (21), 220 (100), 219 (20), 202 (27), 191
(40), 189 (30), 165 (15), 57 (43); exact mass calculate for
C21H20O3 (M+): 320.1412; found 320.1417.
MHz): d 7.98-7.95 (m, 1 H), 7.82-7.78 (m, 1 H), 7.51-7.46
(m, 3 H), 7.16 (d, J = 1.2 Hz, 1 H), 2.69 (s, 3 H), 1.58 (s, 9
H); 13C NMR (CDCl3, 100 MHz): d 152.1 (C), 148.2 (C),
136.5 (C), 133.9 (C), 130.7 (C), 128.4 (CH), 126.3 (CH),
125.5 (CH), 124.1 (CH), 121.4 (CH), 116.4 (CH), 83.5 (C),
27.7 (three CH3), 19.3 (CH3); IR (neat): 3067, 2980, 2934,
1757, 1626, 1602, 1510, 1464, 1421, 1394, 1370, 1348,
1249, 1147, 1053, 1020, 954, 889, 871, 856, 771, 755, 658
cm-1; MS (m/z, relative intensity): 258 (M+, 72), 159 (17),
158 (100), 157 (11), 141 (14), 129 (20), 128 (25), 115 (10),
57 (85); exact mass calculate for C16H18O3 (M+): 258.1256;
found 258.1251.
Spectroscopic data for 4l
TLC Rf = 0.31 (Hexane/EtOAc = 5:1); pale yellow
solid; mp 119-121 °C. Spectroscopic data for 4l: 1H NMR
(CDCl3, 400 MHz): d 8.46 (d, J = 10 Hz, 1 H), 8.24 (d, J =
8.0 Hz, 1 H), 8.06 (d, J = 8.0 Hz, 1 H), 7.71-7.67 (m, 1 H),
7.62-7.56 (m, 1 H), 7.32 (s, 1 H), 6.51 (d, J = 10.0 Hz, 1 H),
2.77 (s, 3 H); 13C NMR (CDCl3, 100 MHz): d 161.1 (C),
153.7 (C), 141.0 (C), 139.1 (CH), 129.8 (C), 129.1 (C),
127.9 (CH), 125.9 (CH), 125.1 (CH), 121.8 (CH), 117.6
(CH), 114.7 (CH), 111.6 (C), 20.0 (CH3); IR (neat): 3075,
2952, 2923, 2857, 1731, 1625, 1590, 1559, 1519, 1458,
Spectroscopic data for 4m
TLC Rf = 0.26 (Hexane/EtOAc = 5:1); red brown
solid; mp 293-295 °C. Spectroscopic data for 4m: 1H NMR
(CDCl3, 400 MHz): d 8.53 (d, J = 10.0 Hz, 1 H), 8.29 (d, J =
8.4 Hz, 1 H), 7.94 (d, J = 8.4 Hz, 1 H), 7.69 (dd, J = 7.6, 7.6
Hz, 1 H), 7.55-7.47 (m, 6 H), 7.41 (s, 1 H), 6.58 (d, J = 10.0
Hz, 1 H); 13C NMR (CDCl3, 100 MHz): d 160.9 (C), 153.3
(C), 145.7 (C), 139.0 (CH), 138.9 (C), 129.7 (CH), 129.5
(C), 129.0 (C), 128.5 (CH), 128.3 (CH), 128.1 (CH), 127.7
416
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J. Chin. Chem. Soc. 2012, 59, 407-420

JOURNAL OF THE CHINESE
CHEMICAL SOCIETY
Synthesis of Natural Occurring Juncaceae Coumarin
(CH), 126.0 (CH), 121.6 (CH), 117.7 (CH), 115.5 (CH),
112.4 (C); IR (neat): 3061, 2924, 2853, 1733, 1623, 1589,
1555, 1518, 1493, 1445, 1417, 1364, 1227, 1169, 1151,
1116, 995, 903, 878, 826, 772, 702 cm-1; MS (m/z, relative
intensity): 272 (M+, 100), 244 (46), 243 (12), 215 (40), 213
(10), 107 (11); exact mass calculate for C19H12O2 (M+):
272.0837; found 272.0840.
(C), 128.1 (CH), 120.6 (CH), 116.0 (CH), 115.2 (CH),
112.4 (C), 22.1 (CH3); IR (neat): 3071, 3045, 2911, 2851,
1720, 1632, 1566, 1509, 1446, 1323, 1208, 1171, 1115,
903, 832, 775 cm-1; MS (m/z, relative intensity): 210 (M+,
100), 195 (31), 183 (13), 182 (89), 181 (29), 153 (24), 152
(33), 151 (13), 77 (10), 76 (20); exact mass calculate for
C14H10O2 (M+): 210.0681; found 210.0688.
Spectroscopic data for 2n
Spectroscopic data for 2o
TLC Rf = 0.72 (Hexane/EtOAc = 10:1); pale yellow
solid; mp 91-93 °C. Spectroscopic data for 2n: 1H NMR
(CDCl3, 400 MHz): d 6.99 (d, J = 7.6 Hz, 1 H), 6.91 (d, J =
7.6 Hz, 1 H), 6.83 (s, 1 H), 6.24 (s, 1 H), 2.94 (t, J = 8.0 Hz,
2 H), 2.53 (t, J = 8.0 Hz, 2 H), 2.28 (s, 3 H), 1.53 (s, 9 H);
13C NMR (CDCl3, 100 MHz): d 151.1 (C), 150.8 (C), 136.0
(C), 133.1 (C), 130.1 (C), 127.3 (CH), 127.1 (CH), 127.0
(CH), 114.2 (CH), 83.2 (C), 28.2 (CH2), 27.7 (three CH3),
26.3 (CH2), 21.0 (CH3); IR (neat): 3007, 2980, 2936, 1752,
1665, 1497, 1475, 1456, 1394, 1370, 1310, 1243, 1134,
1044, 1022, 981, 891, 852, 812, 784, 736, 664 cm-1; MS
(m/z, relative intensity): 260 (M+, 11), 160 (78), 145 (12),
143 (19), 131 (19), 128 (14), 116 (10), 115 (17), 57 (100);
exact mass calculate for C16H20O3 (M+): 260.1412; found
260.1419.
TLC Rf = 0.67 (Hexane/EtOAc = 10:1); colorless liq-
1
uid. Spectroscopic data for 2o: H NMR (CDCl3, 400
MHz): d 6.88 (s, 2 H), 6.46 (s, 1 H), 2.91 (t, J = 8.4 Hz, 2
H), 2.53 (t, J = 8.4 Hz, 2 H), 2.24 (s, 3 H), 2.23 (s, 3 H), 1.54
(s, 9 H); 13C NMR (CDCl3, 100 MHz): d 151.1 (C), 150.3
(C), 132.2 (C), 131.4 (C), 131.3 (C), 131.1 (C), 128.5
(CH), 127.8 (CH), 111.4 (CH), 83.2 (C), 27.7 (three CH3),
25.4 (CH2), 25.3 (CH2), 19.5 (CH3), 19.0 (CH3); IR (neat):
3010, 2978, 2938, 1752, 1668, 1482, 1461, 1369, 1270,
1249, 1138, 1049, 872, 860, 804, 784, 694 cm-1; MS (m/z,
relative intensity): 274 (M+, 50), 175 (11), 174 (100), 159
(11), 157 (17), 57 (67); exact mass calculate for C17H22O3
(M+): 274.1569; found 274.1576.
Spectroscopic data for 3o
TLC Rf = 0.67 (Hexane/EtOAc = 10:1); colorless liq-
1
uid. Spectroscopic data for 3o: H NMR (CDCl3, 400
Spectroscopic data for 3n
TLC Rf = 0.72 (Hexane/EtOAc = 10:1); pale yellow
solid; mp 114-116 °C. Spectroscopic data for 3n: 1H NMR
(CDCl3, 400 MHz): d 7.78 (d, J = 8.8 Hz, 1 H), 7.72 (d, J =
8.8 Hz, 1 H), 7.57 (s, 1 H), 7.53 (d, J = 2.4 Hz, 1 H),
7.29-7.27 (m, 1 H), 7.23 (dd, J = 8.8, 2.4 Hz, 1 H), 2.50 (s, 3
H), 1.58 (s, 9 H); 13C NMR (CDCl3, 100 MHz): d 152.0 (C),
148.8 (C), 136.3 (C), 134.0 (C), 129.6 (C), 129.0 (CH),
128.0 (CH), 127.5 (CH), 126.7 (CH), 119.9 (CH), 117.5
(CH), 83.5 (C), 27.7 (three CH3), 21.7 (CH3); IR (neat):
3050, 2979, 2925, 1752, 1637, 1510, 1454, 1368, 1280,
1261, 1242, 1206, 1148, 1045, 959, 911, 887, 864, 839,
810, 781, 748 cm-1; MS (m/z, relative intensity): 258 (M+,
16), 159 (11), 158 (100), 157 (31), 128 (11), 57 (30); exact
mass calculate for C16H18O3 (M+): 258.1256; found
258.1263.
MHz): d 8.01 (d, J = 9.2 Hz, 1 H), 7.75 (d, J = 2.4 Hz, 1 H),
7.36 (dd, J = 9.2, 2.4 Hz, 1 H), 7.21 (d, J = 7.2 Hz, 1 H),
7.17 (d, J = 7.2 Hz, 1 H), 2.65 (s, 3 H), 2.62 (s, 3 H), 1.59 (s,
9 H); 13C NMR (CDCl3, 100 MHz): d 152.1 (C), 148.5 (C),
133.4 (C), 132.3 (C), 132.2 (C), 130.7 (C), 127.0 (CH),
126.2 (CH), 126.1 (CH), 120.1 (CH), 115.3 (CH), 83.5 (C),
27.8 (three CH3), 19.4 (CH3), 19.3 (CH3); IR (neat): 2978,
2927, 1752, 1667, 1482, 1459, 1369, 1288, 1270, 1250,
1162, 1138, 872, 804 cm-1; MS (m/z, relative intensity):
272 (M+, 100), 173 (11), 172 (100), 157 (22), 128 (10), 57
(29); exact mass calculate for C17H20O3 (M+): 272.1412;
found 272.1417.
Spectroscopic data for 4o
TLC Rf = 0.28 (Hexane/EtOAc = 5:1); white solid;
1
mp 180-182 °C. Spectroscopic data for 4o: H NMR
Spectroscopic data for 4n
(CDCl3, 400 MHz): d 8.92 (d, J = 10.0 Hz, 1 H), 8.21 (d, J =
9.2 Hz, 1 H), 7.49 (d, J = 9.2 Hz, 1 H), 7.37 (d, J = 7.2 Hz, 1
H), 7.29 (d, J = 7.2 Hz, 1 H), 6.47 (d, J = 10.0 Hz, 1 H), 2.94
(s, 3 H), 2.71 (s, 3 H); 13C NMR (CDCl3, 100 MHz): d
160.4 (C), 155.4 (C), 143.0 (CH), 134.0 (C), 132.4 (CH),
131.6 (C), 130.7 (C), 130.2 (CH), 129.6 (C), 126.8 (CH),
116.7 (CH), 114.8 (C), 113.6 (CH), 26.6 (CH3), 20.1 (CH3);
IR (neat): 2965, 2926, 1709, 1614, 1558, 1518, 1449, 1376,
TLC Rf = 0.38 (Hexane/EtOAc = 5:1); pale yellow
solid; mp 152-154 °C. Spectroscopic data for 4n: 1H NMR
(CDCl3, 400 MHz): d 8.44 (d, J = 9.6 Hz, 1 H), 7.95 (s, 1H),
7.90 (d, J = 8.4 Hz, 1 H), 7.78 (d, J = 8.4 Hz, 1 H), 7.39-
7.34 (m, 2 H), 6.52 (d, J = 9.6 Hz, 1 H), 2.59 (s, 3H); 13
C
NMR (CDCl3, 100 MHz): d 160.9 (C), 154.0 (C), 139.1
(CH), 138.4 (C), 132.8 (CH), 129.1 (C), 128.7 (CH), 128.4
J. Chin. Chem. Soc. 2012, 59, 407-420
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Hon et al.
1326, 1229, 1179, 1115, 1027, 993, 911, 831, 785 cm-1; MS
(m/z, relative intensity): 224 (M+, 100), 209 (25), 196 (79),
195 (23), 182 (15), 181 (56), 165 (40), 153 (20), 152 (72),
139 (14), 115 (15), 76 (11); exact mass calculate for
C15H12O2 (M+): 224.0837; found 224.0832.
tensity): 276 (M++3, 34), 274 (M++1, 34), 273 (M+, 54),
248 (49), 246 (50), 195 (11), 167 (18), 140 (12), 139 (100),
138 (21), 137 (13), 113 (13), 87 (14), 69 (10), 63 (15); ex-
act mass calculate for C13H7BrO2 (M+): 273.9629; found
273.9625.
Spectroscopic data for 2p
Spectroscopic data for 2q
TLC Rf = 0.70 (Hexane/EtOAc = 10:1); white solid;
mp 62-64 °C. Spectroscopic data for 2p: 1H NMR (CDCl3,
400 MHz): d 7.26-7.24 (m, 2 H), 6.87 (d, J = 8.0 Hz, 1 H),
6.26 (s, 1 H), 2.96 (t, J = 8.0 Hz, 2 H), 2.55-2.50 (m, 2 H),
1.53 (s, 9 H); 13C NMR (CDCl3, 100 MHz): d 151.1 (C),
150.9 (C), 135.2 (C), 132.2 (C), 130.2 (CH), 129.5 (CH),
127.6 (CH), 120.0 (C), 113.4 (CH), 83.5 (C), 28.4 (CH2),
27.7 (three CH3), 25.8 (CH2); IR (neat): 2980, 2937, 1753,
1665, 1590, 1479, 1370, 1283, 1271, 1255, 1235, 1163,
1135, 859, 813, 782 cm-1; MS (m/z, relative intensity): 324
(M+, 11), 226 (9), 224 (9), 116 (12), 115 (15), 57 (46); exact
mass calculate for C15H17BrO3 (M+): 324.0361; found
324.0369.
TLC Rf = 0.50 (Hexane/EtOAc = 10:1); brown solid;
1
mp 161-163 °C. Spectroscopic data for 2q: H NMR
(CDCl3, 400 MHz): d 8.20 (d, J = 9.2 Hz, 1 H), 8.12 (d, J =
2.0 Hz, 1 H), 8.10 (d, J = 2.0 Hz, 1 H), 8.05 (d, J = 9.2 Hz, 1
H), 7.97-7.92 (m, 3 H), 7.83 (s, 1 H), 6.69 (s, 1H), 3.69 (t, J
= 8.4 Hz, 2 H), 2.81 (t, J = 8.4 Hz, 2 H), 1.58 (s, 9H); 13
C
NMR (CDCl3, 100 MHz): d 151.4 (C), 151.1 (C), 131.3
(C), 131.2 (C), 130.6 (C), 130.0 (C), 128.0 (C), 127.7
(CH), 127.3 (CH), 127.0 (C), 126.9 (CH), 125.6 (CH),
125.1 (CH), 124.9 (C), 124.8 (CH), 124.3 (C), 123.4 (CH),
123.0 (CH), 115.0 (CH), 83.5 (C), 27.7 (three CH3), 26.0
(CH2), 24.8 (CH2); IR (neat): 3040, 2979, 2930, 1752,
1673, 1600, 1439, 1394, 1370, 1277, 1252, 1223, 1145,
1132, 1069, 890, 841, 824, 705 cm-1; MS (m/z, relative in-
tensity): 370 (M+, 100), 271 (22), 270 (100), 269 (15), 253
(11), 241 (27), 240 (20), 239 (48), 228 (30), 227 (15), 226
(26), 57 (43); exact mass calculate for C25H22O3 (M+):
370.1569; found 370.1576.
Spectroscopic data for 3p
TLC Rf = 0.79 (Hexane/EtOAc = 10:1); white solid;
1
mp 120-122 °C. Spectroscopic data for 3p: H NMR
(CDCl3, 400 MHz): d 7.99 (d, J = 2.0 Hz, 1 H), 7.74 (d, J =
8.8 Hz, 1 H), 7.67 (d, J = 8.8 Hz, 1 H), 7.61 (d, J = 2.4 Hz, 1
H), 7.54 (dd, J = 8.8, 2.0 Hz, 1 H), 7.33 (dd, J = 8.8, 2.4 Hz,
1 H), 1.55 (s, 9 H); 13C NMR (CDCl3, 100 MHz): d 151.8
(C), 148.9 (C), 132.3 (C), 132.1 (C), 129.9 (CH), 129.7
(CH), 129.3 (CH), 128.4 (CH), 122.0 (CH), 119.6 (C),
118.2 (CH), 83.8 (C), 27.7 (three CH3); IR (neat): 3013,
2978, 2938, 1749, 1589, 1499, 1456, 1391, 1371, 1330,
1279, 1264, 1240, 1200, 1164, 1058, 1046, 1015, 964, 915,
883, 861, 810, 779, 741 cm-1; MS (m/z, relative intensity):
322 (M+, 65), 224 (98), 222 (100), 195 (21), 193 (21), 143
(15), 126 (25), 115 (25), 114 (30), 113 (15), 88 (10), 57
(90); exact mass calculate for C15H15BrO3 (M+): 322.0205;
found 322.0202.
Spectroscopic data for 3q
TLC Rf = 0.50 (Hexane/EtOAc = 10:1); brown solid;
1
mp 178-180 °C. Spectroscopic data for 3q: H NMR
(CDCl3, 400 MHz): d 9.01 (d, J = 9.2 Hz, 1 H), 8.95 (d, J =
9.2 Hz, 1 H), 8.42 (s, 1 H), 8.29 (d, J = 9.2 Hz, 1 H), 8.21 (d,
J = 7.6 Hz, 1 H), 8.09-8.05 (m, 2 H), 7.98-7.94 (m, 2 H),
7.90 (d, J = 7.6 Hz, 1 H), 7.64 (dd, J = 9.2, 2.4 Hz, 1 H),
1.64 (s, 9 H); 13C NMR (CDCl3, 100 MHz): d 152.0 (C),
149.0 (C), 131.8 (C), 131.4 (C), 131.2 (C), 130.5 (C), 128.2
(CH), 127.9 (CH), 127.8 (CH), 127.4 (C), 126.1 (CH),
126.0 (C), 125.7 (CH), 125.2 (C), 125.1 (CH), 124.7 (CH),
124.3 (CH), 123.5 (C), 122.1 (CH), 120.7 (CH), 118.8
(CH), 83.8 (C), 27.8 (three CH3); IR (neat): 3039, 2979,
2928, 1753, 1624, 1460, 1369, 1275, 1253, 1235, 1144,
894, 840, 798, 687 cm-1; MS (m/z, relative intensity): 368
(M+, 10), 269 (22), 268 (100), 240 (13), 239 (62), 237 (19),
57 (16); exact mass calculate for C25H20O3 (M+): 368.1412;
found 368.1417.
Spectroscopic data for 4p
TLC Rf = 0.31 (Hexane/EtOAc = 5:1); pale orange
solid; mp 198-200 °C. Spectroscopic data for 4p: 1H NMR
(CDCl3, 400 MHz): d 8.43 (d, J = 9.6 Hz, 1 H), 8.11 (s, 1
H), 8.08-8.07 (m, 1 H), 7.90 (d, J = 9.2 Hz, 1 H), 7.76 (dd, J
= 9.2, 1.6 Hz, 1 H), 7.50 (d, J = 9.2 Hz, 1 H), 6.60 (d, J = 9.6
Hz, 1 H); 13C NMR (CDCl3, 100 MHz): d 160.4 (C), 153.8
(C), 138.6 (CH), 131.9 (CH), 131.5 (CH), 131.4 (C), 131.0
(CH), 127.6 (C), 123.1 (CH), 120.0 (C), 118.3 (CH), 116.3
(CH), 113.1 (C); IR (neat): 2920, 2852, 1727, 1563, 1500,
1327, 1188, 1111, 989, 875, 805 cm-1; MS (m/z, relative in-
Spectroscopic data for 4q
TLC Rf = 0.26 (Hexane/EtOAc = 5:1); red brown
solid; mp 293-295 °C. Spectroscopic data for 4q: 1H NMR
(CDCl3, 400 MHz): d 9.08 (d, J = 9.6 Hz, 1 H), 8.91 (d, J =
9.2 Hz, 1 H), 8.73 (d, J = 7.6 Hz, 1 H), 8.35 (d, J = 9.2 Hz, 1
418
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© 2012 The Chemical Society Located in Taipei & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
J. Chin. Chem. Soc. 2012, 59, 407-420

JOURNAL OF THE CHINESE
CHEMICAL SOCIETY
Synthesis of Natural Occurring Juncaceae Coumarin
H), 8.29 (d, J = 7.6 Hz, 1 H), 8.17 (d, J = 7.6 Hz, 1 H),
8.06-7.99 (m, 3 H), 7.67 (d, J = 9.2 Hz, 1 H), 6.63 (d, J = 9.6
Hz, 1 H); 13C NMR (CDCl3, 100 MHz): d 160.9 (C), 154.0
(C), 139.5 (CH), 131.4 (C), 131.1 (C), 131.0 (C), 129.2
(CH), 128.7 (CH), 127.97 (CH), 127.86 (C), 127.7 (CH),
127.0 (C), 126.5 (CH), 126.3 (CH), 125.8 (CH), 124.7 (C),
124.4 (C), 123.0 (C), 121.7 (CH), 117.4 (CH), 116.4 (CH),
115.6 (CH), 113.1 (C); IR (neat): 2920, 2849, 1717, 1619,
1559, 1443, 1297, 1261, 1182, 1110, 862, 835, 792 cm-1;
MS (m/z, relative intensity): 320 (M+, 21), 319 (10), 293
(12), 292 (50), 264 (22), 263 (87), 262 (14), 261 (31), 237
(11), 146 (12), 131 (18); exact mass calculate for C23H12O2
(M+): 320.0837; found 320.0834.
3352, 2920, 2853, 1690, 1627, 1560, 1526, 1451, 1429,
1376, 1250, 1213, 1204, 1166, 1142, 1117, 891, 848, 828,
799 cm-1; MS (m/z, relative intensity): 226 (M+, 100), 209
(11), 199 (13), 198 (88), 197 (25), 169 (16), 141 (18), 139
(15), 115 (18); exact mass calculate for C14H10O3 (M+):
226.0630; found 226.0621.
Supporting Information Available
Spectra data for the new compounds.
ACKNOWLEDGMENT
We acknowledge the financial support for this study
from the National Science Council (NSC), Taiwan, ROC as
well as the support from Instrument Centers, NSC. The
help of Professor Ju-Hsiou Liao in the X-ray analysis is ac-
knowledged. Thanks to the National Center for High-Per-
formance Computing (NCHC) for their assistance in litera-
ture searching.
Spectroscopic data for 5a
TLC Rf = 0.47 (Hexane/EtOAc = 5:1); pale yellow
1
liquid. Spectroscopic data for 5a: H NMR (CDCl3, 400
MHz): d 7.80 (d, J = 9.6 Hz, 1 H), 7.38 (d, J = 7.6 Hz, 1 H),
7.31-7.27 (m, 1 H), 7.21-7.19 (m, 2 H), 6.33 (d, J = 9.6 Hz,
1 H), 3.01 (t, J = 8.0 Hz, 2 H), 2.83 (t, J = 8.0 Hz , 2 H); 13
C
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NMR (CDCl3, 100 MHz): d 161.8 (C), 161.7 (C), 140.4
(CH), 132.9 (C), 130.0 (C), 128.3 (CH), 127.4 (CH), 127.2
(CH), 121.5 (CH), 114.0 (CH), 112.2 (C), 27.6 (CH2), 26.7
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Preparation of 6
To a solution of 4i (1.19 g, 0.495 mmol) in CH2Cl2
(9.5 mL) was added a solution of BBr3 in CH2Cl2 (1 M,
4.95 mL) under N2 at 0 °C. The solution was warm up to
room temperature and stirred for 12 h until the completion
of reaction. The solution was added to a saturated aqueous
NaHCO3 solution, and the mixture was extracted with
CH2Cl2. The organic solution was dried over MgSO4, con-
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was purified by flash column chromatography with 17%
EtOAc-hexane (Rf = 0.33 in 50% EtOAc-hexane) to give 6
as a brown solid (0.93 g, 83% yield); mp 248-250 °C. Spec-
1
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J. Chin. Chem. Soc. 2012, 59, 407-420