Versatile one-pot synthesis of 3-alkenylcoumarins

Article abstract of DOI:10.1002/ejoc.200700819

A variety of 2-acyl-, 2-aroyl- and 2-formyl-substituted phenols are converted in a one-pot reaction with α,β-unsaturated carboxylic acid chlorides into the corresponding 3-alkenylcoumarins. Especially the labile 3-vinylcoumarins are readily available by t

Full text of DOI:10.1002/ejoc.200700819

FULL PAPER
DOI: 10.1002/ejoc.200700819
Versatile One-Pot Synthesis of 3-Alkenylcoumarins
Pia Königs,[a] Olivia Neumann,[a] Kristina Hackelöer,[a] Olga Kataeva,[b] and
Siegfried R. Waldvogel*[a]
Dedicated to Professor W. Pfleiderer on the occasion of his 80th birthday
Keywords: Heterocycles / Alkenes / Domino reaction / Coumarin
A variety of 2-acyl-, 2-aroyl- and 2-formyl-substituted phe-
nols are converted in a one-pot reaction with α,β-unsaturated
carboxylic acid chlorides into the corresponding 3-alkenyl-
coumarins. Especially the labile 3-vinylcoumarins are readily
available by the simple to perform protocol. If longer alkenyl
chains are involved in position 3, small molecules with excel-
lent organo gelating properties are established. The mode of
action for such aggregates is confirmed by X-ray analysis of
an analogue.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2008)
bit alkenyl moieties in position 2. Starting from 2-acetylor-
cinol[10] (1a) we accomplished the styryl derivative 2 follow-
ing a known protocol.[11] Upon switching from cinnamoyl
chloride to crotonyl chloride chromenones were no longer
obtained, but 3-vinylcoumarin 3a was exclusively formed
(Scheme 1).
Introduction
Coumarins are common motifs in a variety of naturally
occurring products and represent the core structure of sev-
eral top-selling drugs like warfarin.[1] Recently, coumarins
have found wide applications in the labelling[2] and caging[3]
of biomolecules. Because of the utmost significance of this
heterocyclic system many strategies for the synthesis of a
variety of substituted coumarins have been elaborated.[4]
Examples of 3-alkenyl- and 3-vinylcoumarins in particular
are scarce since they are considered as labile intermediates.
Early reports describe these compounds as by-products.[5]
For the preparation of 3-vinylcoumarins a multi-step se-
quence was developed including an in situ formation of the
substituent in position 3. The vinyl moiety is usually
trapped in situ by a Diels–Alder reaction with electron-poor
dienophiles.[6] Further investigations of the photochemistry
of the pyrone double bond confirmed its reactivity in [2+2]-
cycloadditions.[7] Since only a limited number of 3-vinylcou-
marins is known the reactions of these compounds were
treated theoretically.[8] Resonance-stabilized derivatives
have been synthesized by palladium-catalyzed reactions and
were only characterized by fluorescence spectroscopy.[9]
Scheme 1. Serendipitous formation of 3-vinylcoumarins.
In contrast to earlier reports,[6,7] compounds like 3a
turned out to be rather stable and could be isolated as
colourless crystals. Suitable crystals for X-ray analysis were
obtained by slow evaporation and allowed structural con-
firmation (Figure 1).
The asymmetric unit of crystalline 3a contains two inde-
pendent molecules of coumarin possessing planar heterocy-
clic moieties as expected. The essential difference between
the two molecules A and B is based on the orientation of
the vinyl groups. One of the coumarin fragments is totally
planar with the attached vinyl group facing the carbonyl
substituent in position 2. In molecule B, the vinyl group is
twisted out of the plane by 50° towards the methyl substitu-
ent in position 4. This provides close packing and orienta-
Results and Discussion
In the course of natural product synthesis we were
prompted to synthesize chromenone derivatives which exhi-
[a] Kékule-Institut für Organische Chemie und Biochemie,
Universität Bonn,
Gerhard-Domagk-Str. 1, 53121 Bonn, Germany
Fax: +49-228-739608
E-mail: waldvogel@uni-bonn.de
[b] A. E. Arbuzov Institute of the Russian Academy of Sciences,
Arbuzov Street 8, Kazan 420088, Russia
Eur. J. Org. Chem. 2008, 343–349
© 2008 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
343

S. R. Waldvogel et al.
FULL PAPER
treated with crotonyl chloride furnishing 3a as sole product
(entry 1). The yield for the 3-alkenylcoumarin derivative
was increased when 3-methyl-2-butenoyl chloride was ap-
plied providing the coumarin with a 2-propenyl substituent
in position 3 (entry 2). Subjecting 1a to a long-chain α,β-
unsaturated acyl chloride afforded an isomeric mixture of
Table 1. Survey of substrates subjected in the isomerizing Kos-
tanecki–Robinson reaction.
Figure 1. A fragment of crystal packing and hydrogen bonding
scheme showing different orientations of the vinyl substituents in
independent coumarin molecules A and B of 3a. Hydrogen bonds
are indicated.
tion favourable for strong intermolecular C=O···HO hydro-
gen bonds (Figure 1). As a result, the crystal packing con-
sists of infinite hydrogen-bonded planar ribbons parallel to
each other with an interplanar distance being equal to
3.4 Å, indicating π···π stacking interactions. All vinyl
groups point to the same side of the particular aggregate.
The illustrated conversion to the 3-alkenylcoumarin can
be described as an isomerizative version of the Kostanecki–
Robinson reaction.
The initial step of the domino reaction[12] involves the
acylation of the phenolic hydroxy group. The intermediate
ester 4 can be detected and in some cases isolated after
short reaction times. The next steps consist of a γ-deproton-
ation and α-attack onto the carbonyl moiety in order to
construct the six-membered heterocycle (Scheme 2). Conse-
quently, this reaction pathway was not possible for the cin-
namate and chromenone 2 was formed. In order to eluci-
date the scope of the one-pot sequence which was found by
serendipity, we subjected a variety of phenolic substrates
with different carbonyl moieties in position 2 to a selection
of α,β-unsaturated acid chlorides. Alteration of the base
mainly resulted in the formation of the corresponding ester
4 (Hünig’s base, DBU and sodium hydride were explored).
γ-Deprotonation is easily accomplished by the use of potas-
sium carbonate and furnishes the coumarin derivative in
satisfying yield. In general, the transformation seems to be
rather slow. The time-consuming step is attributed to the
condensation reaction which requires several hours up to a
few days for good conversions. 2-Acetylorcinol (1a) was
[a] All reactions were carried out with 1.25 equiv. of acyl chloride
and 3.0 equiv. K2CO3 in acetone under reflux conditions. [b] Both
isomers are found, E:Z = 1.8:1.
Scheme 2. Plausible mechanism for the formation of 2-alkenylcou-
marins.
344
www.eurjoc.org
© 2008 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Org. Chem. 2008, 343–349

Versatile One-Pot Synthesis of 3-Alkenylcoumarins
3-alkenylcoumarins. Since the γ-deprotonation is not selec-
tively performed, the subsequent steps result in an olefinic
mixture. 3c is obtained in an E:Z ratio of 1.8:1. Most inter-
estingly, the longer side chain exhibits very pronounced
properties as an organogelator[13] and causes a lower yield
due to the problems during purification. 0.02 m solutions of
3c in a mixture of tert-butyl methyl ether/cyclohexane (1:3)
form a transparent organogel which liquifies upon heating
to 50 °C (Table 1).
The gelating properties are attributed to aggregates by
hydrogen bonding. An arrangement which results in infinite
ribbons similar to the one found in the X-ray analysis of 3a
can be anticipated. Noteworthy, 3c represents an unusual
simple and small molecule as organogelator.[13]
Acetophenones with multiple hydroxy groups yield the
vinylcoumarin system directly (entry 4). If this unprotected
4-hydroxy group is replaced by a methyl group the yield is
significantly increased. The transformation can be extended
to the corresponding 1,3-butadienyl-substituted coumarins
by employing sorbyl chloride.[14] In this particular conver-
sion DBU is the base of choice providing the product al-
most quantitatively and isomerically pure in relatively short
reaction times (entry 6). A variety of differently substituted
acetophenones was tested. The electron-rich substrate 1d is
successfully converted within 12 h, whereas the electron-de-
ficient congener 1e requires significantly prolonged reaction
times and additional acyl chloride (entries 7 and 8). The
situation is ameliorated upon using 3-methyl-2-butenoyl
chloride. The fluorinated coumarin 3h is isolated in 89%
yield. Other alkyl aryl ketones can also be converted into
vinylcoumarins in good yield (entry 10). Due to the low
carbonyl activity these compounds require prolonged reac-
tion times of several days (entries 11 and 12). Even complex
heterocyclic substrates are compatible with this one-pot se-
quence. Salicylic aldehydes are also useful substrates for this
transformation allowing the construction of a variety of 3-
alkenylcoumarins in very good to excellent yield (entries
Experimental Section
General Comments: All reagents were used in analytical grades. Sol-
vents were desiccated if necessary by standard methods. Melting
points were determined with a Melting Point Apparatus SMP3
(Stuart Scientific, Watford Herts, UK) and were uncorrected. Mi-
croanalysis was performed with a Vario EL III (Elementar-Ana-
lysensysteme, Hanau, Germany). NMR spectra were recorded with
a Bruker ARX 300, (Analytische Messtechnik, Karlsruhe, Ger-
many) by calibration on CHCl3 with δ = 7.26 ppm or [D6]DMSO
1
with 2.50 ppm for H NMR spectroscopy. Mass spectra were ob-
tained on a MAT8200 (Finnigan, Bremen, Germany) employing
EI or on a MS50 (Kratos, Manchester, England) or MAT95XL
(Finnigan, Bremen, Germany) employing HRMS. GC Mass Spec-
tra were obtained on a MS-50 (A.E.I., Manchester, GB) employing
EI. Column chromatography was performed on silica gel (particle
size 63–200 μm, Merck, Darmstadt, Germany) using mixtures of
cyclohexane with ethyl acetate as eluents.
General Procedure: At room temperature 2.0 mmol of the corre-
sponding (2-hydroxyphenyl)carbonyl derivative 1 is dissolved in
acetone (10.0 mL). Then 6.0 mmol of potassium carbonate and
2.5 mmol of the α,β-unsaturated acyl chloride are added and the
reaction mixture is stirred for the given time (see Table 1) under
reflux conditions. After the reaction is finished, the suspension is
poured onto ice (20 mL), acidified to pH = 4 with citric acid and
subsequently the aqueous layer is extracted with ethyl acetate
(3ϫ20 mL). The combined organic fractions are washed with H2O
and brine, dried with magnesium sulfate and concentrated under
reduced pressure. Purification of the resulting coumarin derivative
3 is achieved via column chromatography with cyclohexane/ethyl
acetate as eluents.
5-Hydroxy-4,7-dimethyl-3-vinylcoumarin (3a): This compound was
obtained after column chromatography (cyclohexane/ethyl acetate,
75:25, then 50:50) as yellow crystals in 166 mg (38%) yield. Rf =
1
0.27 (cyclohexane/EtOAc, 9:1); m.p. 192 °C. H NMR (300 MHz,
[D6]DMSO, 25 °C): δ = 2.24 (s, 3 H, CH3), 2.63 (s, 3 H, CH3), 5.53
[dd, 1 H, 2J(H,H) = 2.3 Hz, 3J(cisH,H) = 11.7 Hz, HC=CH2], 5.89
[dd, 1 H, 2J(H,H) = 2.3 Hz, 3J(transH,H) = 17.6 Hz, HC=CH2],
6.55 (br., 1 H, Ar-H), 6.62 [dd, 1 H, 3J(cisH,H) = 11.7 Hz,
3J(transH,H) = 17.6 Hz, HC=CH2], 10.54 (s, 1 H, OH) ppm. 13C
13–15). Even synthetically valuable iodo moieties are toler- NMR (75 MHz, [D6]DMSO): δ = 20.5 (CH3), 22.0 (CH3), 108.0
(Cquat), 108.3 (CH), 113.2 (CH), 119.9 [CC(O)O], 122.2
(HC=CH2), 130.4 (HC=CH2), 143.2 (Cquat), 150.5 (Cquat), 154.0
(Cquat), 157.5 (COH), 159.8 [C(O)O]. MS (70 eV, EI): m/z (%) =
216 (100) [M]·+, 188 (24) [M – CO]·+, 151 (56) [C8H7O3]+. HRMS
(EI): m/z [M – H]·+ calcd. for C13H12O3: 215.0714, found 215.0710;
elemental analysis calcd. for C13H12O3: C 72.21, H 5.59; found C
71.33, H 5.50.
ated in this protocol yielding the corresponding iodinated
heterocycle. In this reaction sequence, 2-hydroxy-1-naphth-
aldehyde (1k) furnishes 3-vinylbenzo[f]coumarin (3q) in
good yield.
Conclusions
X-ray Crystal Data for 3a: Formula C13H12O3, M = 216.23, colour-
less crystal, 0.35ϫ0.30ϫ0.10 mm, a = 9.080(1), b = 10.012(1), c =
13.130(1) Å, α = 105.97(1), β = 96.07(1), γ = 109.21(1), V =
1058.0(2) Å3, ρcalc = 1.357 gcm–3, μ = 0.790 mm–1, empirical ab-
sorption correction (0.770 Յ T Յ 0.925), Z = 4, triclinic, space
In conclusion, a versatile and reliable strategy to 3-alken-
ylcoumarins was established. This domino reaction consists
of an O-acylation with a subsequent isomerizative conden-
sation reaction. The one-pot protocol is easily performed
and provides synthetic intermediates which have been de-
scribed before as in-situ-generated species! Since the substi-
¯
group P1 (No. 2), λ = 1.54178 Å, T = 223 K, ω and φ scans, 8825
reflections collected (Ϯh, Ϯk, Ϯl), [(sinθ)/λ] = 0.60 Å–1, 3589 inde-
pendent (Rint = 0.033) and 3238 observed reflections [I Ն 2 σ(I)],
tution pattern of naturally occurring 3-alkenylcoumarins[15] 301 refined parameters, R = 0.057, wR2 = 0.152, max. residual elec-
is easily constructed, the synthesis of the natural products
refined as riding atoms, except for O–H which were located from
phebaclavin G and H will be reported in due course. More-
tron density 0.79 (–0.33) eÅ–3, hydrogen atoms were calculated and
the difference Fourier map and refined isotropically.
over, vinyl and alkenyl moieties exhibit a unique reactivity
which can be exploited in powerful synthetic operations like
Data set for 3a was collected with Nonius KappaCCD dif-
fractometer. Programs used: data collection COLLECT (Nonius
olefin metathesis[16] or stereoselective transformations.[17]
Eur. J. Org. Chem. 2008, 343–349
© 2008 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjoc.org
345

S. R. Waldvogel et al.
FULL PAPER
B.V., 1998), data reduction Denzo-SMN,[18] absorption correction
Denzo,[19] structure solution SHELXS-97,[20] structure refinement
by full-matrix least-squares against F2 using SHELXL-97.
4,6-Dimethyl-3-vinylcoumarin (3e): This compound was obtained
after column chromatography (cyclohexane/ethyl acetate, 90:10) as
light yellow crystals in 350 mg (87%) yield. Rf = 0.20 (cyclohexane/
1
EtOAc, 9:1); m.p. 103 °C. H NMR (400 MHz, CDCl3): δ = 2.42
CCDC-653823 contains the supplementary crystallographic data
for this paper. These data can be obtained free of charge from The
Cambridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/
data_request/cif.
(s, 3 H, CH3), 2.50 (s, 3 H, CH3), 5.65 [dd, 1 H, 2J(H,H) = 2.0 Hz,
3J(cisH,H) = 12.0 Hz, HC=CH2], 6.02 [dd, 1 H, 2J(H,H) = 2.0 Hz,
3J(transH,H) = 17.6 Hz, HC=CH2], 6.72 [dd, 1 H, 3J(cisH,H) =
12.0 Hz, 3J(transH,H) = 17.6 Hz, HC=CH2], 7.18 [d, 1 H, 3J(H,H)
3
= 8.0 Hz, Ar-H], 7.28 [dd, 1 H, J(H,H) = 8.0 Hz, Ar-H], 7.43 (s,
5-Hydroxy-4,7-dimethyl-3-(propen-2-yl)coumarin (3b): This com-
pound was obtained after column chromatography (cyclohexane/
ethyl acetate, 75:25) as light yellow crystals in 360 mg (78%) yield.
Rf = 0.26 (cyclohexane/EtOAc, 75:25); m.p. 231 °C. 1H NMR
(300 MHz, [D6]DMSO): δ = 1.89 (s, 3 H, CH3), 2.27 (s, 3 H, CH3),
2.52 (s, 3 H, CH3), 4.84 (s, 1 H, HC=CH2), 5.28 (s, 1 H, HC=CH2),
6.57 (s, 1 H, Ar-H), 6.58 (s, 1 H, Ar-H), 10.45 (s, 1 H, OH) ppm.
13C NMR (75 MHz, [D6]DMSO): δ = 15.3 (CH3), 21.1 (CH3), 22.2
(CH3), 106.6 (Cquat), 107.3 (CH), 112.0 (CH), 117.2 (C=CH2),
125.2 [CC(O)O], 139.9 (Cquat), 141.8 (C=CH2), 148.2 (Cquat), 153.4
(Cquat), 156.4 (COH), 158.7 [C(O)O] ppm. MS (70 eV, EI): m/z (%)
= 230 (100) [M]·+, 251 (24) [M – CH3]·+, 202 (12) [M – CO]·+.
HRMS (EI): m/z [M – H]+ calcd. for C14H14O3: 229.0870, found
229.0869.
1 H, Ar-H) ppm. 13C NMR (100 MHz, CDCl3): δ = 15.3 (CH3),
21.1 (CH3), 116.4 (CH = CH2), 120.2 (Cquat), 122.6 (CH), 122.8
(CH), 124.9 [CC(O)O], 129.2 (Cquat), 132.1 (CH), 133.7 (CH =
CH2), 146.4 (Cquat), 150.2 (Cquat), 160.2 [C(O)O] ppm. MS (70 eV,
EI): m/z (%) = 200 (100) [M]·+, 199 (68) [M – H]·+, 171 (24) [M –
CO]·+. HRMS (EI): m/z [M – H]+ calcd. for C13H12O2: 199.0765,
found 199.0762; elemental analysis calcd. (%) for C13H12O2 (200.1):
C 77.98, H 6.04; found C 77.09, H 6.14.
3-(Buta-1,3-dienyl)-4,6-dimethylcoumarin (3f): For the synthesis of
3f the general protocol was altered: 2-hydroxy-5-methylacetophe-
none (150 mg, 1.0 mmol), 5.0 mL acetone, potassium carbonate
(0.415 g, 6.0 mmol) and sorbyl chloride[22] (163 mg, 2.5 mmol) were
used. The reaction mixture was stirred under reflux conditions for
14 h. Subsequently, 1,8-diazabicyclo[5.4.0]undec-7-ene (183 mg,
1.2 mmol) was added and the mixture was heated to reflux for ad-
ditional 4 h. 3f was obtained after column chromatography (cyclo-
hexane/ethyl acetate, 95:5) as yellow crystals in 214 mg (95%) yield.
3-[(E)-Buten-1-yl]-5-hydroxy-4,7-dimethylcoumarin (3c): This com-
pound was prepared according to the general procedure using 2,6-
dihydroxy-4-methylacetophenone (0.50 g, 3.0 mmol), 10 mL ace-
tone, potassium carbonate (1.25 g, 9.0 mmol) and (E)-hexenoyl
chloride[21] (0.60 g, 4.5 mmol). 3c was obtained after column
chromatography (cyclohexane/methyl tert-butyl ether, 80:20, then
50:50) as yellow crystals in 425 mg (58%) yield. (E)- and (Z)-Iso-
mer were not separated, ratio E:Z = 1.8:1. NMR spectroscopic
data refer to the (E)-isomer. Rf = 0.28 (cyclohexane/EtOAc, 75:25).
1H NMR (400 MHz, CDCl3): δ = 0.99 (t, 3 H, CH3), 1.95 [quin, 2
1
Rf = 0.11 (cyclohexane/EtOAc, 95:5); m.p. 101–103 °C. H NMR
(400 MHz, CDCl3): δ = 2.34 (s, 3 H, CH3), 2.42 (s, 3 H, CH3), 5.18
[d,
1 = 10.8 Hz, HC=CH2], 5.35 [d, 1 H,
H, 3J(cisH,H)
3J(transH,H) = 16.8 Hz, HC=CH2], 6.43 [td, 1 H, 3J(cisH,H) =
10.8 Hz, 3J(transH,H) = 16.8 Hz, HCCH = CH2], 6.53 [d, 1 H,
3J(H,H) = 15.6 Hz, HC=CH], 7.10 [d, 1 H, J(H,H) = 8.4 Hz, Ar-
3
3
3
H], 7.19 [d, 1 H, J(H,H) = 8.4 Hz, Ar-H], 7.25 [dd, 1 H, J(H,H)
= 10.8 Hz, 3J(H,H) = 15.6 Hz, HC=CH], 7.35 (s, 1 H, Ar-H) ppm.
13C NMR (100 MHz, CDCl3): δ = 15.1 (CH3), 21.1 (CH3), 116.3
(HC=CH2), 119.7 (CH), 120.3 [CC(O)O], 121.7 (Cquat), 124.7
(HCCH=CH2), 124.9 (HCCH = CH2), 132.1 (CH), 131.9 (CH),
133.7 (Cquat), 137.5 (CH), 137.8 (HC=CH2), 145.8 (Cquat), 150.0
(Cquat), 159.8 [C(O)O] ppm. MS (70 eV, EI): m/z (%) = 226 (100)
[M]·+, 211 (26) [M – CH3]·+, 197 (20) [M – C2H5]·+, 183 (36) [M –
C2H3O]·+. HRMS (EI): m/z [M]+ calcd. for C15H14O2: 226.0994,
found 226.0989; elemental analysis calcd. (%) for C15H14O2 (226.1):
C 79.26, H 6.24; found C 78.48, H 6.22.
3
H, J(H,H) = 7.2 Hz, CH2], 2.33 (s, 3 H, CH3), 2.59 (s, 3 H, CH3),
3
3
5.88 [dt, 1 H, J(H,H) = 7.2 Hz, J(H,H) = 11.2 Hz, HC=CH(E)],
3
6.12 [d, 1 H, J(H,H) = 11.2 Hz, CH = CH], 6.53 (s, 1 H, Ar-H),
6.70 (s, 1 H, Ar-H) ppm. 13C NMR (100 MHz, CDCl3): δ = 13.6
(CH3), 21.2 (CH3), 23.2 (CH3), 27.3 (CH2CH3), 108.1 (Cquat), 110.0
(CH), 113.0 (CH), 120.9 [CC(O)O], 121.6 (HC=CH), 139.0
(HC=CH), 142.5 (Cquat), 150.3 (Cquat), 154.3 (Cquat), 154.9 (COH),
161.7 [C(O)O] ppm. MS (70 eV, EI): m/z (%) = 244 (100) [M]·+,
229 (82) [M – CH3]·+, 215 (83) [M – C2H5]·+, 201 (37) [M –
C2H3O]·+, 151 (18) [C8H7O3]+. HRMS (EI): m/z [M]·+ calcd. for
C15H16O3: 244.1099, found 244.1104.
6-Methoxy-4-methyl-3-vinylcoumarin (3g): This compound was ob-
tained after column chromatography (cyclohexane/ethyl acetate,
90:10) as light yellow crystals in 260 mg (60%) yield. Rf = 0.21
(cyclohexane/EtOAc, 9:1); m.p. 80 °C. 1H NMR (400 MHz,
CDCl3): δ = 2.49 (s, 3 H, CH3), 3.86 (s, 3 H, OCH3), 5.66 [dd, 1
7-Hydroxy-4-methyl-3-vinylcoumarin (3d): This compound was ob-
tained after column chromatography (cyclohexane/ethyl acetate,
75:25) as light yellow crystals in 255 mg (62%) yield. Recrystalli-
zation from CH2Cl2 furnished the analytically pure product. Rf =
0.18 (cyclohexane/EtOAc, 75:25); m.p. 177–179 °C. 1H NMR
(300 MHz, [D6]DMSO): δ = 2.43 (s, 3 H, CH3), 5.50 [dd, 1 H,
2J(H,H) = 2.1 Hz, 3J(cisH,H) = 11.7 Hz, CH=CH2], 6.00 [dd, 1 H,
2
3
H, J(H,H) = 2.0 Hz, J(cisH,H) = 12.0 Hz, HC=CH2], 6.02 [dd,
1 H, 2J(H,H) = 2.0 Hz, J(transH,H) = 17.6 Hz, HC=CH2], 6.72
3
[dd,
1 = = 17.6 Hz,
H, 3J(cisH,H) 12.0 Hz, 3J(transH,H)
HC=CH2], 7.06 [d, 1 H, 3J(H,H) = 7.2 Hz, Ar-H], 7.08 (s, 1 H, Ar-
H), 7.22 [d, 1 H, 3J(H,H) = 7.2 Hz, Ar-H] ppm. 13C NMR
3
2J(H,H) = 2.1 Hz, J(transH,H) = 17.4 Hz, CH=CH2], 6.67 [d, 1
H, 4J(H,H) = 2.1 Hz, Ar-H], 6.71 [dd, 1 H, 3J(H,H) = 9.0 Hz,
4J(H,H) = 2.1 Hz, Ar-H], 6.78 [dd, 1 H, 3J(cisH,H) = 11.7 Hz,
3J(transH,H) = 17.4 Hz, CH = CH2], 7.65 [d, 1 H, 3J(H,H) =
9.0 Hz, Ar-H], 10.52 (s, 1 H, OH) ppm. 13C NMR (75 MHz, [D6]-
DMSO): δ = 14.8 (CH3), 101.7 (CH = CH2), 112.3 (Cquat), 113.0
(CH), 117.1 [CC(O)O], 120.6 (CH), 127.2 (CH), 129.3 (CH = CH2),
148.1 (Cquat), 153.3 (Cquat), 159.1 [C(O)O], 160.8 (COH) ppm. MS
(70 eV, EI): m/z (%) = 202 (100) [M]·+, 201(44) [M – H]·+, 174 (32)
[M – C2H4]·+. HRMS (EI): m/z [M – H]·+ calcd. for C12H10O3:
201.0557, found 201.0555; elemental analysis calcd. (%) for
C12H10O3 (202.1): C 71.28, H 4.98; found C 69.25, H, 5.12.
(100 MHz, CDCl3):
δ = 15.4 (CH3), 55.82 (OCH3), 108.2
(HC=CH2), 117.6 (Cquat), 117.7 (CH), 118.0 (CH), 121.0 [CC(O)
O], 123.0 (Cquat), 129.2 (CH), 146.1 (HC=CH2), 146.5 (Cquat),
155.9 (Cquat), 160.1 (Cquat), 160.0 [C(O)O] ppm. MS (70 eV, EI):
m/z (%) = 216 (100) [M]·+, 215 (46) [M – H]·+, 188 (12) [M –
CO]·+. HRMS (EI): m/z [M – H]+ calcd. for C13H12O3: 215.0714,
found 215.0706; elemental analysis calcd. (%) for C13H12O3 (216.1):
C 72.21, H 5.59; found C 71.64, H 5.51.
6-Fluoro-4-methyl-3-vinylcoumarin (3h): This compound was ob-
tained after column chromatography (cyclohexane/ethyl acetate,
346
www.eurjoc.org
© 2008 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Org. Chem. 2008, 343–349

Versatile One-Pot Synthesis of 3-Alkenylcoumarins
3
75:25) and recrystallisation from ethanol (4.0 mL) as colourless
3J(H,H) = 7.2 Hz, Ar-H], 7.22 [td, 1 H, J(H,H) = 7.2 Hz, Ar-H],
3
crystals in 259 mg (64%) yield. Rf = 0.59 (cyclohexane/EtOAc,
7.27 [m, 3 H, J(H,H) = 7.8 Hz, Ar-H] ppm. 13C NMR (75 MHz,
CDCl3): δ = 116.4 (HC=CH2), 120.7 (Cquat), 121.3 (Cquat), 122.4
1
75:25); m.p. 93 °C. H NMR (300 MHz, [D6]DMSO): δ = 2.47 (s,
3 H, CH3), 5.62 [dd, 1 H, 2J(H,H) = 2.1 Hz, 3J(cisH,H) = 11.7 Hz,
(CH), 124.0 (CH), 128.8 (CH), 128.8 (CH), 129.4 (CH), 131.3
HC=CH2], 6.05 [dd, 1 H, 2J(H,H) = 2.1 Hz, 3J(transH,H) = (CH), 134.4 [CC(O)O], 150.9 (Cquat), 152.4 (Cquat), 159.7 [C(O)O].
17.4 Hz, HC=CH2], 6.74 [dd,
1 =
H, 3J(cisH,H) 11.7 Hz, MS (70 eV, EI): m/z (%) = 248 (100) [M]·+, 219 (36) [M – CHO]·+,
3J(transH,H) = 17.4 Hz, HC=CH2], 7.42 [s, 1 H, 3J(H, F) = 9.8 Hz,
Ar-H], 7.45 [d, 1 H, 3J(H,H) = 4.8 Hz, Ar-H], 7.66 [dd, 1 H,
3J(H,F) = 8.1 Hz, 4J(H,H) = 2.8 Hz, Ar-H] ppm. 13C NMR
203 (40) [M – CHO2]·+, 189 (20) [M – C2H3O2]·+. HRMS (EI): m/z
[M – H]+ calcd. for C17H12O2: 247.0765, found 247.0762; elemental
analysis calcd. (%) for C17H12O2 (248.1): C 82.24; H 4.87, found C
(75 MHz, [D6]DMSO): δ = 15.6 (CH3), 111.9 [2J(C,F) = 24.9 Hz, 81.83, H 4.91.
CH], 118.4 [3J(C,F) = 8.6 Hz, CH], 119.0 [2J(C,F) = 24.4 Hz, CH],
4-(1-Phenyl-1H-pyrazolyl)-3-vinylcoumarin (3l): Variation from the
121.6 [3J(C,F) = 8.4 Hz, Cquat], 122.4 (C-3), 129.6 (HC=CH2),
147.3 (Cquat), 148.2 (Cquat), 157.5 [1J(C,F) = 238.6 Hz, CF], 159.0
[C(O)O] ppm. MS (70 eV, EI): m/z (%) = 205/204 (14/100) [M]·+,
176/175 (14/36) [M – CO]·+. HRMS (EI): m/z [M – H]+ calcd. for
C12H9FO2: 203.0514, found 203.0508; elemental analysis calcd. (%)
for C12H9O2F (204.1): C 70.58, H 4.44; found C 70.49, H 4.21.
general procedure: after the reaction mixture was stirred under re-
flux conditions for two days, further 1.3 mmol acyl chloride was
added. Work up was performed after three days of stirring under
reflux conditions, respectively. 4-(2-Hydroxybenzoyl)-1-phenyl-1H-
pyrazole (264 mg, 1.0 mmol), 15.0 mL acetone, potassium carbon-
ate (0.415 g, 6.0 mmol) and 2-butenoyl chloride (131 mg, 1.3 mmol)
were used. 3l was obtained after column chromatography (cyclo-
hexane/ethyl acetate, 80:20) as colourless crystals in 186 mg (59%)
6-Fluoro-4-methyl-3-(propen-2-yl)coumarin (3i): This compound
was obtained after column chromatography (cyclohexane/ethyl ace-
tate, 90:10) as colourless crystals in 354 mg (81%) yield. Rf = 0.22
(cyclohexane/EtOAc, 9:1); m.p. 151 °C. 1H NMR (300 MHz,
CDCl3): δ = 2.00 (s, 3 H, CH3), 2.36 (s, 3 H, CH3), 4.91 (s, 1 H,
1
yield. Rf = 0.43 (cyclohexane/EtOAc, 8:2); m.p. 124 °C. H NMR
(400 MHz, CDCl3): δ = 5.52 [dd, 1 H, 2J(H,H) = 3.6 Hz,
3J(cisH,H) = 10.4 Hz, HC=CH2], 6.51 [dd, 1 H, 2J(H,H) = 3.6 Hz,
3J(transH,H) = 17.6 Hz, HC=CH2], 6.55 [dd, 1 H, 3J(cisH,H) =
10.4 Hz, 3J(transH,H) = 17.6 Hz, HC=CH2], 7.20 [td, 1 H, 3J(H,H)
= 7.2 Hz, 4J(H,H) = 1.2 Hz, Ar-H], 7.37 [t, 1 H, 3J(H,H) = 7.2 Hz,
3
C=CH2), 5.36 (s, 1 H, C=CH2), 7.16 [dd, 1 H, J(H,H) = 9.0 Hz,
3
4J(H,F) = 2.7 Hz, Ar-H], 7.23 [dd, 1 H, J(H,F) = 7.8 Hz, Ar-H],
7.25 [td, 1 H, 3J(H,H) = 9.0 Hz, 4J(H,H) = 2.7 Hz 3J(H,F) =
3
4
8.7 Hz, Ar-H] ppm. 13C NMR (75 MHz, CDCl3): δ = 15.9 (CH3), Ar-H], 7.48 [dd, 1 H, J(H,H) = 8.4 Hz, J(H,H) = 1.6 Hz, Ar-H],
22.3 (CH3), 110.6 [2J(C,F) = 28.4 Hz, CH], 118.0 [CC(O)O], 118.1 7.52 (m, 4 H, Ar-H), 7.77 [dd, 1 H, J(H,H) = 8.4 Hz, J(H,H) =
3
4
[3J(H,F) = 11.2 Hz, Cquat], 118.1 [2J(H,F) = 25.1 Hz, CH], 121.3
[3J(C,F) = 8.3 Hz, CH], 130.1 (C=CH2), 139.5 (C=CH2), 145.2
1.2 Hz, Ar-H], 7.79 (s, 1 H, HCN), 8.08 (s, 1 H, HC=N) ppm. 13C
NMR (100 MHz, CDCl3): δ = 115.9 (Cquat), 116.6 (HC=CH2),
(Cquat), 148.5 (Cquat), 157.1 [1J(C,F) = 251.8 Hz, Cquat], 160.4 119.2 (2ϫCH), 120.3 [CC(O)O], 122.3 (Cquat), 123.0 (CH), 124.2
[C(O)O]. MS (70 eV, EI): m/z (%) = 219/218 (15/100) [M]·+, 203 (CH), 127.0 (CH), 127.2 (CH), 127.4 (CH), 129.4 (CH), 129.6
(28) [M – CH3]·+, 189 (10) [M – CO]·+. HRMS (EI): m/z [M – H]+
calcd. for C13H11FO2: 217.0670, found 217.0664; elemental analysis
calcd. (%) for C13H11O2F (218.1): C 71.55, H 5.08; found C 71.43,
H 4.85.
(2ϫCH), 131.4 (Cquat), 139.5 (HC=CH2), 141.5 (CH), 141.6
(Cquat), 152.4 (Cquat), 159.4 [C(O)O] ppm. MS (70 eV, EI): m/z (%)
=
314 (100) [M]·+, 286 (60) [M CO]·+, 269 (20) [M
– –
CHO2]·+. HRMS (EI): m/z [M]+ calcd. for C20H14N2O2: 313.0983,
found 313.0977; elemental analysis calcd. (%) for C20H14N2O2
(314.1): C 76.42, H 4.49; found C 76.20, H 4.50.
4-Ethyl-3-vinylcoumarin (3j): This compound was obtained after
column chromatography (cyclohexane/ethyl acetate, 90:10) as yel-
lowish oil in 316 mg (79%) yield. Rf = 0.35 (cyclohexane/EtOAc,
7-Methoxy-3-vinylcoumarin[23] (3m): This compound was obtained
after column chromatography (cyclohexane/ethyl acetate, 75:25) as
9:1). 1H NMR (300 MHz, CDCl3): δ = 1.23 [t, 3 H, 3J(H,H) =
3
7.8 Hz, CH3], 2.89 [q, 2 H, J(H,H) = 7.8 Hz, CH2CH3], 5.58 [dd, yellow crystals in 392 mg (97%) yield. Rf = 0.48 (cyclohexane/
1 H, 2J(H,H) = 2.1 Hz, 3J(cisH,H) = 11.7 Hz, CH=CH2], 6.15 [dd,
EtOAc, 75:25); m.p. 118 °C. 1H NMR (300 MHz, CDCl3): δ = 3.85
(s, 3 H, OCH3), 5.39 [dd, 1 H, 2J(H,H) = 1.2 Hz, 3J(cisH,H) =
11.4 Hz, HC=CH2], 6.08 [dd, 1 H, 2J(H,H) = 1.2 Hz, 3J(transH,H)
3
1 H, 2J(H,H) = 2.1 Hz, J(transH,H) = 17.4 Hz, CH=CH2], 6.66
[dd, 1 H, 3J(cisH,H) = 11.7 Hz, 3J(transH,H) = 17.4 Hz, CH =
3
4
CH2], 7.24 [td, 1 H, J(H,H) = 8.1 Hz, J(H,H) = 1.5 Hz, Ar-H], = 17.7 Hz, HC=CH2], 6.67 [dd, 1 H, 3J(cisH,H) = 11.4 Hz,
7.26 [d, 1 H, 3J(H,H) = 8.1 Hz, Ar-H], 7.43 [td, 1 H, 3J(H,H) =
8.1 Hz, Ar-H], 7.61 [dd, 1 H, 4J(H,H) = 1.5 Hz, 3J(H,H) = 8.1 Hz,
Ar-H] ppm. 13C NMR (75 MHz, CDCl3): δ = 13.5 (CH3), 21.6
(CH2CH3), 116.9 (CH = CH2), 119.2 (Cquat), 121.3 (CH), 122.6
3J(transH,H) = 17.7 Hz, HC=CH2], 6.79 (s, 1 H, Ar-H), 6.83 [dd,
1 H, 3J(H,H) = 8.7 Hz, Ar-H], 7.36 [d, 1 H, 3J(H,H) = 8.7 Hz, Ar-
H], 7.63 (s, 1 H, Ar-H) ppm. 13C NMR (100 MHz, CDCl3): δ =
55.7 (OCH3), 100.4 (HC=CH2), 112.8 (CH), 113.0 (Cquat), 118.1
[CC(O)O], 124.2 (CH), 124.7 (CH), 128.3 (CH = CH2), 131.0 (CH), 121.6 [CC(O)O], 128.7 (CH), 130.6 (CH), 137.8 (HC=CH2),
(Cquat), 152.0 (Cquat), 152.5 (CH), 160.0 [C(O)O] ppm. MS (70 eV, 154.8 (Cquat), 160.4 (CH), 162.5 [C(O)O]. MS (70 eV, EI): m/z (%)
EI): m/z (%) = 200 (100) [M]·+, 185 (70) [M – CH3]·+, 157 (38) [M –
C2H3O]·+. HRMS (EI): m/z [M]+ calcd. for C13H12O2: 200.0837,
found 200.0838.
= – –
202 (100) [M]·+, 174 (20) [M CO]·+, 159 (52) [M
C2H3O]·+. HRMS (EI): m/z [M]+ calcd. for C15H10O2: 202.0630,
found 222.0625.
4-Phenyl-3-vinylcoumarin (3k): This compound was obtained after
column chromatography (cyclohexane/ethyl acetate, 95:5) as yellow
7-Methoxy-3-(propen-2-yl)coumarin (3n): This compound was ob-
tained after column chromatography (cyclohexane/ethyl acetate,
80:20) and recrystallization from ethanol as colourless crystals in
crystals in 368 mg (50%) yield. Rf = 0.39 (cyclohexane/EtOAc, 9:1);
1
m.p. 146–148 °C. H NMR (300 MHz, CDCl3): δ = 5.13 [dd, 1 H, 406 mg (94%) yield. Rf = 0.37 (cyclohexane/EtOAc, 8:2); m.p. 99–
2J(H,H) = 2.1 Hz, 3J(cisH,H) = 11.4 Hz, HC=CH2], 6.00 [dd, 1 H,
3J(cisH,H) = 11.4 Hz, 3J(transH,H) = 18.0 Hz, HC=CH2], 6.17
[dd, 1 H, 2J(H,H) = 2.1 Hz, 3J(transH,H) = 18.0 Hz, HC=CH2],
100 °C. H NMR (400 MHz, CDCl3): δ = 2.13 (s, 3 H, CH3), 3.86
(s, 3 H, OCH3), 5.30 (s, 1 H, C=CH2), 5.86 (s, 1 H, C=CH2), 6.79
1
[d, 4J(H,H) = 2.4 Hz, 1 H, Ar-H], 6.83 [dd, 1 H, 4J(H,H) = 2.4 Hz,
3
3
3
6.76 [dd, 1 H, J(H,H) = 8.1, Ar-H], 6.87 [td, 1 H, J(H,H) = 8.1, 3J(H,H) = 8.0 Hz, Ar-H], 6.37 [d, 1 H, J(H,H) = 8.0 Hz, Ar-H],
Ar-H], 6.99 [dd, 2 H, 3J(H,H) = 7.8 Hz, Ar-H], 7.10 [dd, 1 H,
7.59 (s, 1 H, Ar-H) ppm. 13C NMR (100 MHz, CDCl3): δ = 22.2
Eur. J. Org. Chem. 2008, 343–349
© 2008 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjoc.org
347

S. R. Waldvogel et al.
FULL PAPER
(CH3), 55.7 (OCH3), 100.2 (C=CH2), 112.6 (CH), 112.9 (Cquat), (CH), 132.6 (Cquat), 133.6 (HC=CH2), 152.6 (Cquat), 160.1 [C(O)O]
118.3 (CH), 125.1 [CC(O)O], 128.7 (CH), 138.2 (CH), 138.3
(C=CH2), 154.9 (Cquat), 160.0 (Cquat), 162.4 [C(O)O] ppm. MS
(70 eV, EI): m/z (%) = 216 (100) [M]·+, 201 (20) [M – CH3]·+, 188
(24) [M – CO]·+, 173 (56) [M – C2H3O]·+. HRMS (EI): m/z [M]+
calcd. for C13H12O3: 216.0786, found 216.0785; elemental analysis
calcd. (%) for C13H12O3 (216.1): C 72.21, H 5.59; found C 71.80,
H 5.75.
ppm. MS (70 eV, EI): m/z (%) = 222 (100) [M]·+, 194 (52) [M –
CO]·+, 165 (32) [C13H9]+. HRMS (EI): m/z [M – -H]+ calcd. for
C15H10O2: 222.0681, found 222.0679.
Acknowledgments
The studies were supported by the University of Bonn. Financial
support by BASF AG is highly appreciated. The authors are grate-
ful to Dr. Roland Fröhlich for the possibility to use X-ray facilities
at the University of Münster.
7-Methoxy-3-(2-methylpropen-2-yl)coumarin (3o): This compound
was prepared according to the general procedure using 2-hydroxy-
4-methoxybenzaldehyde (304 mg, 2.0 mmol), 10.0 mL acetone, po-
tassium carbonate (0.83 g, 6.0 mmol) and 4-methyl-2-pentenoyl
chloride (296 mg, 2.5 mmol).[24] 3o was obtained after column
chromatography (cyclohexane/ethyl acetate, 80:20) and recrystalli-
zation from ethanol as colourless crystals in 408 mg (89%) yield.
Rf = 0.46 (cyclohexane/EtOAc, 8:2); m.p. 91–93 °C. 1H NMR
(400 MHz, CDCl3): δ = 1.88 (s, 3 H, HC=CCH3), 1.93 (s, 3 H,
HC=CCH3), 3.85 (s, 3 H, OCH3), 6.17 (s, 1 H, HC=C), 6.79 [d, 1
H, 4J(H,H) = 2.4 Hz, Ar-H], 6.83 [dd, 1 H, 4J(H,H) = 2.4 Hz,
[1] a) A. Pape, J. Tebbejohanns, Intensivmed. 2005, 42, 74; b) Het-
erocyclic Chemistry, 4th ed. (Eds.: J. A. Joule, K. Mills),
Blackwell Science Ltd., Oxford, 2006, pp. 170–189; c) M. Dar-
barwar, V. Sundaramurthi, Synthesis 1982, 337–388; d) M. F.
Dean, Fortschr. Chem. Org. Naturst. 1952, 9, 225–291; e)
R. D. H. Murray, Fortschr. Chem. Org. Naturst. 1978, 35, 199–
429; f) R. D. H. Murray, J. Méndez, S. A. Brown, The natural
coumarins: occurrence, chemistry, and biochemistry, Wiley,
Chichester, 1982; g) J. D. Hepworth, in Comprehensive Hetero-
cyclic Chemistry, vol. 3, 1st ed. (Eds.: A. R. Katritzky, C. W.
Rees), Pergamon Press Ltd., Oxford, 1984, pp. 799–809; h)
G. R. Geen, J. M. Evans, A. K. Vong, in Comprehensive Het-
erocyclic Chemistry II, vol. 5, 1st ed. (Eds.: A. R. Katritzky,
C. W. Rees, E. F. V. Scriven), Pergamon Press Ltd., Oxford,
1984, pp. 469–500.
3
3J(H,H) = 8.8 Hz, Ar-H], 6.34 [d, 1 H, J(H,H) = 8.8 Hz, Ar-H],
7.44 (s, 1 H, Ar-H) ppm. 13C NMR (100 MHz, CDCl3): δ = 19.9
(HC=CCH3), 26.9 (HC=CCH3), 55.7 (OCH3), 100.2 (HC=C),
112.6 (CH), 112.9 (Cquat), 118.3 (CH), 125.1 [CC(O)O], 128.7 (CH),
138.2 (CH), 138.3 (HC=C), 154.9 (Cquat), 160.0 (COCH3), 162.4
[C(O)O] ppm. MS (70 eV, EI): m/z (%) = 230 (100) [M]·+, 215 (20)
[M – CH3]·+, 202 (16) [M – CO]·+, 187 (28) [M – C2H3O]·+. HRMS
(EI): m/z [M]+ calcd. for C14H14O3: 230.0943, found 230.0941; ele-
mental analysis calcd. (%) for C13H12O3 (230.1): C 73.03, H 6.13;
found C 72.74, H 6.06.
[2] a) J. Goddard, J. Reymond, Trends Biotechnol. 2004, 22, 363–
370; b) S. Heiner, H. Detert, H. Kunz, Bioorg. Med. Chem.
2006, 14, 6149–6164.
[3] a) G. Mayer, A. Heckel, Angew. Chem. 2006, 118, 5020–5042;
Angew. Chem. Int. Ed. 2006, 45, 4900–4921; b) Dynamic Studies
in Biology, 1st ed. (Ed.: M. Goeldner, R. Givens), Wiley-VCH,
Weinheim, 2005; c) D. Geißler, Y. N. Antonenko, R. Schmidt,
S. Keller, O. O. Krylova, B. Wiesner, J. Bendig, P. Pohl, V.
Hagen, Angew. Chem. 2005, 117, 1219–1223; Angew. Chem. Int.
Ed. 2005, 44, 1195–1198.
[4] a) A. C. Williams, N. Camp, in Science of Synthesis, vol. 14,
1st ed. (Ed.: J. Thomas), Thieme, Stuttgart, 2003, pp. 350–438;
b) J. D. Hepworth, C. D. Gabbutt, M. Heron, in Comprehensive
Heterocyclic Chemistry II, vol. 5, 1st ed. (Eds.: A. R. Katritzky,
C. W. Rees, E. F. V. Scriven), Pergamon Press Ltd., Oxford,
1984, pp. 417–425.
6-Iodo-3-(2-methylpropen-2-yl)coumarin (3p): This compound was
prepared according to the general procedure, using 2-hydroxy-5-
iodobenzaldehyde (248 mg, 1.0 mmol), 10.0 mL acetone, potassium
carbonate (0.42 g, 3.0 mmol) and 4-methyl-2-pentenoyl chloride
(165 mg, 1.25 mmol).[24] 3p was obtained after column chromatog-
raphy (cyclohexane/ethyl acetate, 90:10) as colourless crystals in
124 mg (38%) yield. Rf = 0.60 (cyclohexane/EtOAc, 9:1); m.p.117–
118 °C. 1H NMR (400 MHz, CDCl3): δ = 1.90 (s, 3 H, HC=CCH3),
1.96 (s, 3 H, HC=CCH3), 6.22 (s, 1 H, HC=CCH3), 7.06 [d, 1 H,
3J(H,H) = 8.8 Hz, Ar-H], 7.39 (s, 1 H, Ar-H), 7.71 [dd, 1 H,
4J(H,H) = 2.0 Hz, J(H,H) = 8.8 Hz, Ar-H], 7.79 [d, 1 H, J(H,H)
= 2.0 Hz, Ar-H] ppm. 13C NMR (100 MHz, CDCl3): δ = 20.0
(HC=CCH3), 27.1 (HC=CCH3), 87.1 (HC=CCH3), 118.2 [2J(C,I)
= 23.4 Hz, CI], 121.7 (Cquat), 126.8 [CC(O)O], 135.7 (CH), 136.8
(CH), 139.0 (CH), 141.7 (HC=C), 152.3 (Cquat), 160.8 [C(O)O]
ppm. MS (70 eV, EI): m/z (%) = 326 (100) [M]·+, 298 (16) [M –
CO]·+, 283 (12) [M – C2H3O]·+. HRMS (EI): m/z [M]+ calcd. for
C13H11IO2: 325.9804, found 325.9798, elemental analysis calcd. (%)
for C13H11IO2 (326.0): C 47.88, H 3.40; found C 47.29, H 3.34.
3
4
[5] a) H. Kritzler, F. Bohlmann, Chem. Ber. 1957, 90, 1512–1518;
b) F. Bohlmann, Chem. Ber. 1957, 90, 1519–1529.
[6] T. Minami, Y. Matsumoto, S. Nakamura, S. Koyanagi, M. Ya-
maguchi, J. Org. Chem. 1992, 57, 167–173.
[7] a) M. Yasuda, T. Kishi, C. Goto, H. Satoda, K. Shima, K.
Nakabayashi, Jpn. J. Photochem. Photobiol. A 1993, 76, 61; b)
M. Yasuda, T. Kishi, C. Goto, H. Satoda, K. Nakabayashi, T.
Minami, K. Shima, Tetrahedron Lett. 1992, 33, 6465–6468.
[8] a) M. Pasikowska, P. Fiedorow, H. Koroniak, THEOCHEM
2005, 713, 193–199; b) M. Pasikowska, P. Fiedorow, H. Koron-
iak, THEOCHEM 2005, 728, 71–77; H. Koroniak, M. Pasi-
kowska, P. Fiedorow, Pol. J. Chem. 2003, 77, 1523–1528.
[9] a) M. Schiedel, C. A. Briehn, P. Bäuerle, Angew. Chem. 2001,
113, 4813–4816; Angew. Chem. Int. Ed. 2001, 40, 4677–4680;
b) M. Schiedel, C. A. Briehn, P. Bäuerle, J. Organomet. Chem.
2002, 653, 200–208.
[10] K. Tsujihara, M. Hongu, K. Saito, H. Kawanashi, K. Kuri-
yama, M. Matsumoto, A. Oku, K. Ueta, M. Tsuda, A. Saito,
J. Med. Chem. 1999, 42, 5311–5324.
[11] B. P. Reddy, G. L. D. Krupadanam, J. Heterocycl. Chem. 1996,
33, 1561–1565.
3-Vinylbenzo[f]coumarin (3q): This compound was obtained after
column chromatography (cyclohexane/ethyl acetate, 90:10) as yel-
low crystals in 320 mg (72%) yield. Rf = 0.24 (cyclohexane/EtOAc,
1
9:1); m.p. 132 °C. H NMR (400 MHz, CDCl3): δ = 5.54 [dd, 1 H,
2J(H,H) = 1.2 Hz, 3J(cisH,H) = 11.6 Hz, HC=CH2], 6.30 [dd, 1 H,
3
2J(H,H) = 1.2 Hz, J(transH,H) = 17.6 Hz, HC=CH2], 6.82 [dd, 1
H, 3J(cisH,H) = 11.6 Hz, 3J(transH,H) = 17.6 Hz, HC=CH2], 7.42
3
3
[d, 1 H, J(H,H) = 8.8 Hz, Ar-H], 7.56 [td, 1 H, J(H,H) = 7.2 Hz,
4J(H,H) = 1.6 Hz, Ar-H], 7.68 [t, 1 H, 3J(H,H) = 7.2 Hz, Ar-H],
7.88 [d, 1 H, 3J(H,H) = 8.0 Hz, Ar-H], 7.92 [d, 1 H, 3J(H,H) =
8.0 Hz, Ar-H], 8.24 [d, 1 H, 4J(H,H) = 1.6 Hz, Ar-H], 8.42 (s, 1 H,
Ar-H) ppm. 13C NMR (100 MHz, CDCl3): δ = 113.4 (HC=CH2),
116.6 (Cquat), 119.6 (CH), 121.4 (CH), 123.9 (CH), 126.0 (CH),
128.1 (C-H), 128.9 (Cquat), 129.0 (CH), 130.3 [CC(O)O], 131.0
[12] L. F. Tietze, G. Brasche, K. Gericke, Domino Reactions in Or-
ganic Synthesis, 1st ed., Wiley-VCH, Weinheim, 2006.
[13] a) P. Terech, R. G. Weiss, Chem. Rev. 1997, 97, 3133–3159; b)
J. H. van Esch, B. L. Feringa, Angew. Chem. 2000, 112, 2351–
348
www.eurjoc.org
© 2008 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Org. Chem. 2008, 343–349

Versatile One-Pot Synthesis of 3-Alkenylcoumarins
2354; Angew. Chem. Int. Ed. 2000, 39, 2263–2266; c) R. J. H.
Hafkamp, M. C. Feiters, R. J. M. Nolte, J. Org. Chem. 1999,
64, 412–426.
[19] Z. Otwinowski, D. Borek, W. Majewski, W. Minor, Acta Crys-
tallogr., Sect. A 2003, 59, 228–234.
[20] G. M. Sheldrick, Acta Crystallogr., Sect. A 1990, 46, 467–473.
[21] (E)-2-Hexenoic acid was synthesized according to: D. Herme-
ling, H. J. Schäfer, Chem. Ber. 1988, 121, 1151–1158.
[14] T. Hudlicky, J. P. Sheth, Tetrahedron Lett. 1979, 29, 2667–2670.
[15] a) J. Zappel, J. Reisch, Z. Naturforsch. B: Chem. Sci. 1992, 47,
1801–1802; b) M. Colombain, C. Girard, F. Muyard, F. Béva- [22] Sorbyl chloride was synthesized according to: T. Hudlicky, J. P.
lot, F. Tillequin, P. G. Waterman, J. Nat. Prod. 2002, 65, 458–
Sheth, Tetrahedron Lett. 1979, 29, 2667–2670.
[23] IR-, UV-spectra and microanalyses can be found in: F.
Bohlmann, Chem. Ber. 1957, 90, 1519–1529.
[24] (E)-4-Methyl-2-pentenoyl chloride was synthesized according
to: Y. Tanoue, A. Terada, Bull. Chem. Soc. Jpn. 1987, 60, 3039–
3040.
461.
[16] Handbook of Metathesis, 1st ed. (Ed.: R. H. Grubbs), Wiley-
VCH, Weinheim, 2003.
[17] Catalytic Asymmetric Synthesis, 2nd ed. (Ed.: I. Ojima), Wiley-
VCH, Weinheim, 2003.
[18] Z. Otwinowski, W. Minor, Methods Enzymol. 1997, 276, 307–
326.
Received: September 4, 2007
Published Online: October 9, 2007
Eur. J. Org. Chem. 2008, 343–349
© 2008 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjoc.org
349