Liu et al.
FULL PAPER
Experimental
MHz, CDCl
3
) δ: 161.38, 159.95, 152.69, 152.21, 132.43,
1
2
22.86, 121.33, 117.73, 113.90, 111.86, 107.00, 55.99,
5.79, 22.07, 18.68, 17.93. The NMR spectra of 3b
All the solvents were purified according to standard
procedures and all chemicals were reagent grade and
used as purchased. 8-Iodocoumarins were synthesized
by literature procedure. Reactions were monitored
through thin layer chromatography (TLC) on silica gel
precoated glass plates. Flash column chromatography
was performed using a Qingdao Haiyang flash silica gel
[6]
match the literature data.
4
-Ethyl-7-methoxy-8-(3-methylbut-2-en-1-yl)-2H-
[9]
chromen-2-one (3c) White solid. Yield 80%. m.p.
1
9
8
5-97 ℃; H NMR (400 MHz, CDCl
.8 Hz, 1H), 6.85 (d, J=8.8 Hz, 1H), 6.14 (s, 1H), 5.23
3
) δ: 7.45 (d, J=
1
13
(t, J=6.7 Hz, 1H), 3.92 (s, 3H), 3.54 (d, J=7.1 Hz, 2H),
2.76 (q, J=7.3 Hz, 2H), 1.85 (s, 3H), 1.67 (s, 3H), 1.31
(
200-300 mesh). H NMR and C NMR spectra were
1
recorded on a Bruker ( H, 400 MHz) spectrometer using
tetramethylsilane as the internal standard. Coupling
constants are given in Hertz. The following abbrevia-
tions are used to indicate the multiplicity: s, singlet; d,
double; t, triplet; m, multiplet. The melting points were
determined on an X-4 binocular microscope melting
point apparatus (Beijing Tech Instruments Co., Beijing,
China) and were uncorrected. HR-MS were recorded on
an IonSpec FT-ICR mass spectrometer with ESI re-
source.
13
(
t, J=7.3 Hz, 3H); C NMR (101 MHz, CDCl
3
) δ:
1
61.83, 159.79, 157.73, 152.37, 132.50, 122.40, 121.32,
1
17.96, 113.22, 109.91, 106.99, 55.99, 25.81, 24.7+3,
2
2.11, 17.95, 12.31. HRMS (ESI) calcd for ([M+Na] )
2
95.1310, found 295.1310.
7
-Methoxy-8-(3-methylbut-2-en-1-yl)-4-(trifluoro-
methyl)-2H-chromen-2-one (3d) White solid. Yield
1
5
7
6%. m.p. 93-94 ℃; H NMR (400 MHz, CDCl
.58 (d, J=9.0 Hz, 1H), 6.93 (d, J=9.0 Hz, 1H), 6.63
3
) δ:
(
s, 1H), 5.21 (t, J=7.3 Hz, 1H), 3.97 (s, 3H), 3.56 (d,
1
3
General procedure for synthesis of osthole deriva-
tives
J=7.3 Hz, 2H), 1.86 (s, 3H), 1.69 (s, 3H); C NMR
(101 MHz, CDCl ) δ: 160.86, 159.53, 153.13, 141.75 (q,
3
J=32.6 Hz), 133.07, 123.84, 123.82, 121.75 (q, J=
The 8-iodocoumarin (1.0 mmol) was charged to an
oven-dried Schlenk flask under nitrogen and was dis-
solved with anhydrous THF (8 mL). To this solution,
i-PrMgCl (2.0 mol/L in THF, 1.2 mmol) was added
slowly via syringe at −20 ℃. And the mixture was
stirred for 1 h at the same temperature. Then the mixture
was added slowly to another oven-dried Schlenk flask
which was charged with CuI (0.5 mmol), LiCl (0.5
mmol), isoprenyl bromide (1.0 mmol) and anhydrous
THF (2 mL) under nitrogen at −20 ℃. The reaction
mixture was stirred for 30 min at −20 ℃, and then was
warmed to room temperature. After that the mixture was
stirred for about 10 h and was quenched with a saturated
2
76.7 Hz), 120.62, 118.66, 112.31, 112.26, 112.20,
1
12.14, 107.87, 107.43, 56.15, 25.77, 22.09, 17.91.
+
HRMS (ESI) calcd for ([M+Na] ) 335.0866, found
3
35.0867.
7
-Methoxy-8-(3-methylbut-2-en-1-yl)-4-phenyl-
2
1
7
1
H-chromen-2-one (3e) White solid. Yield 61%. m.p.
1
08-109 ℃. H NMR (400 MHz, CDCl
3
) δ: 7.53-
.47 (m, 3H), 7.45-7.39 (m, 2H), 7.28 (t, J=5.8 Hz,
H), 6.78 (d, J=8.9 Hz, 1H), 6.21 (s, 1H), 5.27 (dddd,
J=7.3, 5.9, 2.7, 1.4 Hz, 1H), 3.91 (s, 3H), 3.59 (d, J=
13
7
.3 Hz, 2H), 1.87 (s, 3H), 1.69 (d, J=0.9 Hz, 3H); C
3
NMR (101 MHz, CDCl ) δ: 161.36, 160.13, 156.01,
NH
4
Cl solution. The organic layer was separated and
152.92, 135.95, 132.69, 129.41, 128.74, 128.44, 125.50,
121.23, 118.17, 113.02, 111.95, 107.01, 56.04, 25.8+4,
22.18, 18.00. HRMS (ESI) calcd for ([M +Na] )
343.1305, found 343.1308.
aqueous layer was extracted with ethyl acetate (10
mL×3); the combined organic layers were washed with
brine (10 mL) and dried over anhydrous Na SO , fil-
2 4
tered, and then concentrated under reduced pressure.
The crude product was purified by silica gel column
chromatography (petroleum ether/ethyl acetate=20∶1)
to afford the final compound.
4,7-Dimethoxy-8-(3-methylbut-2-en-1-yl)-2H-
chromen-2-one (3f) White solid. Yield 63%. m.p.
1
122-123 ℃; H NMR (400 MHz, CDCl
3
) δ: 7.65 (d,
J=8.8 Hz, 1H), 6.85 (d, J=8.9 Hz, 1H), 5.59 (s, 1H),
5.24 (t, J=7.3 Hz, 1H), 3.98 (s, 3H), 3.93 (s, 3H), 3.55
Osthole (3a) White solid. Yield 80%. m.p. 78-79
1
13
℃
; H NMR (400 MHz, CDCl
3
) δ: 7.61 (d, J=9.4 Hz,
(d, J=7.2 Hz, 2H), 1.85 (s, 3H), 1.68 (s, 3H); C NMR
1
6
3
H), 7.29 (d, J=8.6 Hz, 1H), 6.83 (d, J=8.6 Hz, 1H),
.23 (d, J=9.4 Hz, 1H), 5.22 (t, J=7.3 Hz, 1H), 3.92 (s,
H), 3.53 (d, J=7.2 Hz, 2H), 1.84 (s, 3H), 1.67 (s, 3H);
3
(101 MHz, CDCl ) δ: 166.97, 163.54, 160.50, 152.08,
132.53, 121.29, 121.27, 117.63, 109.29, 106.89, 87.65,
56.16, 56.01, 25.79, 22.15, 17.94. HRMS (ESI) calcd
1
3
+
C NMR (101 MHz, CDCl
3
) δ: 161.41, 160.23, 152.83,
for ([M+Na] ) 297.1097, found 297.1102.
1
9
3
43.78, 132.65, 126.23, 121.13, 117.95, 112.98, 107.36,
9.99, 56.06, 25.80, 21.93, 17.95. The NMR spectra of
7-Methoxy-3,4-dimethyl-8-(3-methylbut-2-en-1-
yl)-2H-chromen-2-one (3g) White solid. Yield 83%.
[
5]
1
a match the literature data.
-Methoxy-4-methyl-8-(3-methylbut-2-en-1-yl)-
H-chromen-2-one (3b) White solid. Yield 81%. m.p.
m.p. 80-81 ℃; H NMR (400 MHz, CDCl
3
) δ: 7.41 (d,
7
J=8.8 Hz, 1H), 6.83 (d, J=8.8 Hz, 1H), 5.22 (t, J=7.2
Hz, 1H), 3.90 (s, 3H), 3.54 (d, J=7.2 Hz, 2H), 2.35 (s,
2
7
8
1
13
8-79 ℃; H NMR (400 MHz, CDCl
3
) δ: 7.30 (d, J=
3H), 2.18 (s, 3H), 1.84 (s, 3H), 1.65 (s, 3H); C NMR
.8 Hz, 1H), 6.74 (d, J=8.8 Hz, 1H), 5.99 (s, 1H), 5.13
3
(101 MHz, CDCl ) δ: 162.47, 158.86, 150.75, 146.16,
(
2
t, J=6.9 Hz, 1H), 3.82 (s, 3H), 3.42 (d, J=7.2 Hz, 2H),
.26 (s, 3H), 1.74 (s, 3H), 1.56 (s, 3H); C NMR (101
132.38, 122.41, 121.50, 118.87, 114.63, 112.06, 106.90,
55.96, 25.81, 22.04, 17.94, 15.08, 13.19. HRMS (ESI)
1
3
1354
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© 2015 SIOC, CAS, Shanghai, & WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Chin. J. Chem. 2015, 33, 1353—1358