Intramolecular Diels-Alder reaction of 1,7,9-decatrienoates catalyzed by indium(III) trifluoromethanesulfonate in aqueous media

Article abstract of DOI:10.1016/j.tet.2005.05.062

The intramolecular Diels-Alder reaction of ester-tethered 1,7,9-decatrienoate derivatives in a mixture of water and 2-propanol was catalyzed by indium(III) triflate to give the cycloadducts in good yield with perfect endo-selectivity.

Full text of DOI:10.1016/j.tet.2005.05.062

Tetrahedron 61 (2005) 7087–7093
Intramolecular Diels–Alder reaction of 1,7,9-decatrienoates
catalyzed by indium(III) trifluoromethanesulfonate
in aqueous media
*
Hikaru Yanai, Akio Saito and Takeo Taguchi
School of Pharmacy, Tokyo University of Pharmacy and Life Science, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan
Received 30 April 2005; revised 16 May 2005; accepted 17 May 2005
Available online 13 June 2005
Abstract—The intramolecular Diels–Alder reaction of ester-tethered 1,7,9-decatrienoate derivatives in a mixture of water and 2-propanol
was catalyzed by indium(III) triflate to give the cycloadducts in good yield with perfect endo-selectivity.
q 2005 Elsevier Ltd. All rights reserved.
1. Introduction
(Scheme 1).10,11 Towards to this issue, we have reported
that bis-aluminated triflic amide TfN[Al(Me)Cl]2, a novel
bidentate Lewis acid, efficiently promoted the IMDA
reaction of 1,7,9-decatrienoate derivatives presumably due
to the restriction to the cisoid conformation in some extent
and decrease in LUMO level of dienophile part through the
bidentate coordination of the ester group,12,13 although in
some cases stoichiometric amount of this aluminated triflic
amide was essentially needed for the smooth reaction.
Continuously, we have focused our attention to find out
more efficient Lewis acid. It was demonstrated by several
examples that in a highly polar solvent such as water or
DMSO, repulsive dipole interaction between the two
oxygen atoms in the ester moiety may be weakened,
thereby the energy difference between the transoid
geometry and the cisoid geometry in polar solvent should
be smaller than that in non-polar solvent. For example, Jung
et al. reported that the IMDA reaction of the ester-tethered
trienoate derivatives in DMSO14 and Oshima et al. reported
the intramolecular radical addition reaction of alkenyl
iodoacetate in water.15 Both reactions were found to
efficiently proceed by using such polar solvent. Taking
into account this polar solvent effect on the conformation of
ester compounds, we examined the IMDA reaction of 1,7,9-
Nowadays, the use of aqueous media or water as a sole
solvent has been attracting much interest not only from the
viewpoint of green chemistry, but also due to a number of
examples of highly regio- and/or stereoselective reactions
achieved specifically in aqueous solvent.1 These involves
synthetically important carbon–carbon bond forming
reactions such as allylation of carbonyl compounds,2 aldol
reaction,3 Diels–Alder reaction4 and the transition metal
catalyzed cross-coupling reactions.5,6 Furthermore, during
these days extensive efforts have been made to develop a
variety of Lewis acid catalyzed reactions using rare earth
metal triflates7,8 such as Sc(OTf)3 and Yb(OTf)3 or
indium(III) salts9 which are found to work efficiently in
aqueous media or in water.
Study on the intramolecular Diels–Alder (IMDA) reactions
of ester-tethered trienoate derivatives is one of our ongoing
research projects. It is well documented that contrary to
hydrocarbon substrates or amide-tethered substrates, ester-
tethered triene compounds show lower reactivity in the
IMDA reaction due to the conformational preference of the
transoid form over the cisoid form in which the diene and
dienophile are in close proximity required for the reaction to
proceed. This fact is explained by repulsive dipole
interaction between the two oxygen atoms in ester moiety
and steric repulsion between the two alkyl substituents
existing in the carboxylic acid part and in the alcohol part
Keywords: Intramolecular Diels–Alder reaction; 1,7,9-Decatrienoates;
Indium(III)triflate; Aqueous media.
*
Corresponding author. Tel./fax: C81 426 76 3257; e-mail:
taguchi@ps.toyaku.ac.jp
Scheme 1. IMDA reaction of ester-tethered trienoate derivative.
0040–4020/$ - see front matter q 2005 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tet.2005.05.062

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H. Yanai et al. / Tetrahedron 61 (2005) 7087–7093
decatrienoates in aqueous media using various water-
compatible Lewis acids and as a result, In(OTf)3
(20 mol%) was found to nicely catalyze the reaction. Detail
is reported in this paper.
conducted in the presence of 0.6 M equiv of TfOH, but the
yield of 2a was only 47% (entry 11). This result should
indicate that the IMDA reaction is catalyzed by In(OTf)3 in
this aqueous media.
Next, we examined the effect of the ratio of water on the
product yield. Results are shown in Figure 1 by plotting the
yield of 2a on y axis and the water-content (H2O in
2-propanol, vol%) on x axis. The best result was obtained
when the ratio of H2O–iPrOH was 6:1 (85.7 v/v%, 82%
yield, entry 6). Increase in water content resulted in a
remarkable drop of the product yield and without
2-propanol, namely in water 2a was formed only in 20%
yield (entries 7 and 8). As the water content decreased to 80,
75 and 50 v/v%, the yield of 2a was also gradually lowered
to 71, 64 and 34%, respectively (entries 3–5), and when the
water content was between 50 and 0 v/v%, very little
difference in the product yield was observed keeping in a
range of 35–40% yield (entries 1–3).
2. Results and discussion
The IMDA reaction of (3E)-3,5-hexadienyl acrylate 1a was
conducted to examine the efficiency of various water-
compatible Lewis acids. Results are summarized in Table 1.
In a mixture of water and 2-propanol (6:1 v/v) reaction of 1a
in the presence of stoichiometric amount of Sc(OTf)3 at
60 8C for 24 h gave the IMDA product 2a in low yield (8%
yield, entry 1). Yb(OTf)3 also gave similar result (11%
yield, entry 2). Any appreciable improvement in the yield of
2a was not realized by the use of Gd(OTf)3, Ho(OTf)3,
Cu(OTf)2, Zn(OTf)2, AgOTf. On the other hand, InCl3
promoted the reaction efficiently to give 2a in 51% yield
with complete endo-selectivity after 12 h at 60 8C, although
100 mol% InCl3 was used (entry 3). As shown in entries 4–
6, with catalytic amount of In(OTf)3 the reaction proceeded
smoothly. That is, the use of 20 mol% In(OTf)3 at 70 8C for
12 h resulted in the isolation of 2a in 82% yield (entry 5),
while in the cases of either 100 or 10 mol% of In(OTf)3
yields of 2a were lowered to 56 and 60%, respectively and
in the latter case the reaction rate significantly decreased
(entries 4 and 6).
To see the scope and limitation of the In(OTf)3 catalyzed
IMDA reaction in aqueous media, we examined the IMDA
reaction of 1,7,9-decatrienoates 1b–g having a different
substituent pattern. Results are summarized in Table 2.
Compared to the model substrate 1a, 5-methyl derivative 1b
(R1ZMe, R2–5ZH) showed a similar reactivity to give the
endo-adduct 2b as a single isomer after 8 h at 70 8C (76%
yield, entry 1). The IMDA reaction of 6,10-dimethylated
substrate 1c (R2,4ZMe, R1,3,5ZH) and 8-methylated
substrate 1d (R3ZMe, R1,2,4,5ZH) gave products 2c and
2d in 71 and 83% yield, respectively (entries 2 and 3). The
IMDA adduct 2c was a mixture of two diastereomers, and
the stereochemistry of the major one was determined to
have cis-relationship between angular hydrogen and
6-methyl group (cis/transZ4.9:1). The reaction of 10-
methyl derivative 1e (R4ZMe, R1–3,5ZH) required longer
time (24 h) and higher temperature (80 8C) to give the
IMDA product 2e in moderate yield (68%, entry 4), and the
reaction of more lipophilic 10-propyl derivative 1f required
much longer reaction time even at higher temperature
(under reflux condition) to give 2f in only 18% yield (entry
Concerning the co-solvent, 2-propanol gave the best result
(entry 5), while the product yield lowered to 39 and 52%,
respectively when methanol or 2-methyl-2-propanol was
used (entries 7 and 8). It should be noted that in the In(OTf)3
catalyzed IMDA reaction of 1a aqueous media is crucial to
obtain the product 2a in good yield. For example, reaction in
2-propanol under the similar conditions provided 2a in low
yield (39%, entry 9). Reaction in aprotic solvent such as 1,2-
dichloroethane failed to obtain 2a, but gave a complex
mixture (entry 10). To check if a trace amount of
trifluoromethanesulfonic acid (TfOH) liberated from
In(OTf)3 acts as a Brønsted acid catalyst, reaction was
Table 1. Effect of Lewis acids on IMDA reaction of (3E)-3,5-hexadienyl acrylate (1a)
Entry
Lewis acid (mol%)
Solvent
Temp. (8C)
Time (h)
Yield (%)a
1
2
3
4
Sc(OTf)3 (100)
Yb(OTf)3 (100)
InCl3 (100)
H2O–iPrOH (6:1)
H2O–iPrOH (6:1)
H2O–iPrOH (6:1)
H2O–iPrOH (6:1)
H2O–iPrOH (6:1)
H2O–iPrOH (6:1)
H2O–MeOH (6:1)
H2O–tBuOH (6:1)
iPrOH
60
60
60
70
70
70
70
70
70
70
70
24
24
12
12
12
12
12
12
12
12
12
8
11
51
56
82
60
39
52
39
—
47
In(OTf)3 (100)
In(OTf)3 (20)
In(OTf)3 (10)
In(OTf)3 (20)
In(OTf)3 (20)
In(OTf)3 (20)
In(OTf)3 (20)
TfOH (60)
5
6b
7
8
9
10c
11
ClCH2CH2Cl
H2O–iPrOH (6:1)
a Isolated yield.
b 87% conversion.
c Complex mixture was obtained.

H. Yanai et al. / Tetrahedron 61 (2005) 7087–7093
7089
and the simultaneous ring-contraction from the six
membered lactone to the five membered lactone occurred
to give the cis-fused oxabicyclo[4.3.0]nonene compound 2h
in 55% yield as a mixture of diastereomers in a ratio of cis/
transZ2.8:1. Since the relative configuration between the
angular hydrogen atom and the hydroxymethyl group in the
major diastereomer was confirmed to be cis, this major
isomer 2h-cis was possibly formed through the IMDA
reaction via endo-boat axial transition state leading to the
cis-fused oxabicyclo[4.4.0]decene derivative B, which, in
turn, re-lactonized stereospecifically to the thermodynami-
cally stable five membered ring system 2h-cis.17 Likewise,
the formation of the minor isomer 2h-trans, which has the
trans configuration between the hydroxymethyl group and
the angular hydrogen atom, can be explained by considering
the endo-boat equatorial transition state in the IMDA
reaction steps followed by the re-lactonization. Since it was
reported that diastereo (endo/exo) control in the IMDA
reaction of 1,6,8-nonatrienoate derivatives is quite difficult,
our present result provides a highly endo-selective and
convenient mean for oxabicyclo[4.3.0]nonene system.18
Figure 1. The plots of the yield and the water-content (H2O in 2-propanol,
volume %) on the IMDA reaction of 1a.
5). The reaction of reactive maleic monoester 1g proceeded
at room temperature to give the product 2g in 78% yield as a
single isomer (entry 6).
Since certain examples demonstrated that indium(III) salts
were recyclable Lewis acids,9 we also examined recycling
experiment of In(OTf)3 used in the IMDA reaction of
trienoate 1d as a model substrate (Scheme 3). Extraction of
the reaction mixture of the first run with diethyl ether left the
aqueous phase, which without any modification was used
for the second run giving rise to the IMDA product 2d in the
comparable yield (78%) to that obtained in the first run.
Since the present In(OTf)3 catalyzed IMDA reaction
smoothly proceeded with the 1,7,9-decatrienoate derivative
having active hydrogen as in the case of carboxylic acid 1g,
the reaction of the substrate having C6-hydroxyl group 1h
was conducted (Scheme 2).16 In this case the IMDA reaction
Table 2. IMDA reaction of 1,7,9-decatrienoate derivatives in aqueous media
Entry
1
1
R1
R2
H
R3
H
R4
H
R5
H
Temp. (8C)
Time (h)
8
Products 2
Yield (%)a
1b
Me
70
2b
2c
2d
76
2
3
1c
H
H
Me
H
H
Me
H
H
H
70
70
14
12
71b
C
1d
Me
83
4
5
1e
1f
H
H
H
H
H
H
Me
H
H
80
24
24
2e
2f
68
18
n-Pr
Reflux
6
1g
H
H
H
H
CO2H
rt
24
2g
78
a Isolated yield.
b cis/transZ4.9:1 based on isolated yield.

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H. Yanai et al. / Tetrahedron 61 (2005) 7087–7093
Scheme 2. IMDA reaction of 6-hydroxy substrate (1h).
Scheme 3. Recycling experiment of In(OTf)3.
Likewise, in the third run 2d was also isolated in essentially
similar yield (79%), indicating that In(OTf)3 was recyclable
catalyst for the present IMDA reaction.
friendly solvents and In(OTf)3 used as the catalyst is
recyclable without troublesome purification, these results
provide useful examples from a viewpoint of green chemistry.
Finally, the effect of In(OTf)3 on the IMDA reaction of
acrylamide derivative 1i was examined (Scheme 4). The
IMDA reaction of amide-tethered substrate 1i under thermal
conditions was reported by Martin et al.19 to proceed in
toluene at 85 8C for 12 h to give a mixture of 2i-endo and 2i-
exo in 63% yield (endo/exoZ6.9:1). 20 mol% In(OTf)3
catalyzed reaction in a mixture of water and 2-propanol
(6:1 v/v) proceeded at lower temperature (50 8C, 12 h) to
give the cycloadduct 2i-endo as a sole stereoisomer (74%
yield). On the other hand, the use of bidentate Lewis acid
TfN[Al(Me)Cl]2 reduced the yield of product 2i (41%
yield).
4. Experimental
4.1. General
Indium(III) trifluoromethanesulfonate is available commer-
cially. All reactions were carried out under argon
atmosphere. 1H NMR (400 MHz) and 13C NMR
(100.6 MHz) spectra were recorded on a 400 MHz
spectrometer, and chemical shifts were reported in parts
per million (ppm) using CHCl3 (7.26 ppm) in CDCl3 for 1H
NMR, and CDCl3 (77.01 ppm) for 13C NMR as an internal
standard, respectively. Mass spectra (MS) were obtained by
EI or ESI technique. Medium pressure liquid chromato-
graphy (MPLC) was performed using pre-packed column
(silica gel, 50 mm) with UV or RI detector.
3. Conclusion
We have demonstrated that catalytic amount of In(OTf)3 in
a mixture of water and 2-propanol can promote the IMDA
reaction of the various 1,7,9-decatrienoate derivatives to
give the corresponding cycloadducts in good yield with
perfect endo-selectivity. Since the present reaction proceeds
quite nicely in water and 2-propanol as environmentally
4.2. General procedure for preparation of 1,7,9-decatri-
enoate derivatives: (3E,5E)-3,5-heptadienyl acrylate (1e)
After a suspension of (3-hydroxypropyl)triphenyl-phos-
phonium bromide20 (7.06 g, 17.0 mmol) in THF (25 mL)
Scheme 4. IMDA reaction of N–H acrylamide derivative (1i).

H. Yanai et al. / Tetrahedron 61 (2005) 7087–7093
7091
was treated with lithium bis(trimethylsilyl)amide (LHMDS,
35 mL, 1.0 M in THF) for 1 h at 0 8C, crotonaldehyde
(2.80 g, 40.0 mmol) was added at 0 8C. The reaction
mixture was stirred for 3 h at 0 8C. After usual work-up
(extracted with Et2O, dried over MgSO4, and concentrated
under reduced pressure), the residue was purified by flash
column chromatography on silica gel (hexane/Et2OZ15:1)
to give (3E,5E)-3,5-heptadien-1-ol (1.03 g, 9.18 mmol, 54%
yield) as colorless oil. 1H NMR spectrum of this compound
was identical with that reported in the literature.21 To a
solution of this dienyl alcohol (561 mg, 5.0 mmol) in
CH2Cl2 (10 mL), acryloyl chloride (0.45 mL, 5.5 mmol)
and triethylamine (0.83 mL, 6.0 mmol) were added at 0 8C.
After being stirred at room temperature for 2 h, the reaction
mixture was quenched by H2O and extracted with Et2O
(10 mL!3). The organic layer was washed with brine and
dried over MgSO4. Purification by column chromatography
(hexane/Et2OZ50:1) gave the product 1e (689 mg, 85%
MS m/z: 195 [MCH]C. HRMS Calcd for C12H19O2 [MC
H]C: 195.1385, Found: 195.1400.
4.2.2. (Z)-4-[(3E)-3,5-Hexadienyloxy]-4-oxo-2-butenoic
acid (1g). After a solution of 3,5-hexadien-1-ol (981 mg,
10.0 mmol) in CH2Cl2 (25 mL) was treated with maleic
anhydride (981 mg, 10.0 mmol) and 4-dimethylamino-
pyridine (DMAP, 24.5 mg, 0.20 mmol) for 3 h at 0 8C, the
reaction mixture was extracted with EtOAc (10 mL!3).
The organic layer was washed with brine, dried over
MgSO4, and purified by silica gel column chromatography
(hexane/EtOAcZ3:1) to give 1g (746 mg, 3.8 mmol, 38%
yield) and 3,5-hexadien-1-ol (549 mg, 5.6 mmol). Colorless
oil. IR (neat) n cmK1; 3025, 1731, 1712. 1H NMR
(400 MHz, CDCl3) d 2.51 (2H, t, JZ6.7 Hz), 4.33 (2H, t,
JZ6.7 Hz), 5.05 (1H, d, JZ10.1 Hz), 5.16 (1H, d, JZ
14.8 Hz), 5.69–5.74 (1H, m), 6.14 (1H, dd, JZ14.8,
10.4 Hz), 6.24–6.35 (1H, m), 6.37 (1H, d, JZ12.7 Hz),
6.47 (1H, d, JZ12.7 Hz). 13C NMR (100.6 MHz, CDCl3) d
31.4, 66.1, 116.8, 128.2, 128.9, 134.2, 136.4, 137.1, 167.0,
171.2. ESI-MS m/z: 197 [MCH]C. HRMS Calcd for
C10H13O4 [MCH]C: 197.0798, Found: 197.0814.
1
yield). Colorless oil. IR (neat) n cmK1; 1726. H NMR
(400 MHz, CDCl3) d 1.72 (3H, d, JZ6.9 Hz), 2.42 (2H, q,
JZ6.8 Hz), 4.18 (2H, t, JZ6.9 Hz), 5.45–5.55 (1H, m),
5.57–5.68 (1H, m), 5.81 (1H, dd, JZ10.4, 1.5 Hz), 5.96–
6.14 (2H, m), 6.12 (1H, dd, JZ17.3, 10.4 Hz), 6.39 (1H, dd,
JZ17.3, 1.5 Hz). 13C NMR (100.6 MHz, CDCl3) d 18.0,
31.9, 63.9, 126.1, 128.3, 128.5, 130.6, 131.2, 132.9, 166.2.
EI-MS m/z: 166 [M]C. Anal. Calcd for C10H14O2: C, 72.26;
H, 8.49. Found: C, 72.17; H, 8.24.
4.3. Typical procedure for IMDA reaction of 1,7,9-
decatrienoate derivatives in aqueous media: (4aS*,7S*,
8aR*)-7-methyl-3,4,4a,7,8,8a-hexahydro-1H-iso-
chromen-1-one (2e)
The substrates 1a–d, 1h12a,b and 1i19 were prepared
according to the reported procedure. The physical data of
1a–d, 1h and 1i were reported previously.
To a solution of indium(III) triflate (56.0 mg, 0.1 mmol) in
H2O (6.0 mL), a solution of 1,7,9-decatrienoate 1e
(83.1 mg, 0.5 mmol) in 2-propanol (1.0 mL) was added at
room temperature and then the reaction mixture was stirred
at 80 8C for 24 h. After the resulting mixture was extracted
with Et2O (5 mL!3), the organic layer was washed with
brine and dried over MgSO4. Purification by column
chromatography on silica gel (hexane/EtOAcZ3:1) gave
the product 2e (56.5 mg, 68% yield) as colorless oil. IR
4.2.1. (3E,5E)-3,5-Nonadienyl acrylate (1f). In a similar
manner for the preparation of (3E,5E)-3,5-heptadien-1-ol,
reaction of (3-hydroxypropyl)triphenylphosphonium
bromide (7.06 g, 17.0 mmol) with LHMDS (35 mL, 1.0 M
in THF) and E-2-hexenal (4.60 mL, 40 mmol), and the
subsequent purification by flash column chromatography on
silica gel (hexane/EtOAcZ25:1) gave (3E,5E)-3,5-non-
adien-1-ol (1.19 g, 8.5 mmol, 50% yield) as colorless oil. IR
(neat) n cmK1; 3340, 3016, 1653, 986. 1H NMR (400 MHz,
CDCl3) d 0.90 (3H, t, JZ7.4 Hz), 1.42 (2H, qt, JZ7.4,
7.2 Hz), 2.04 (2H, q, JZ7.2 Hz), 2.29–2.39 (2H, m), 3.66
(2H, bs), 5.48–5.68 (2H, m), 5.97–6.18 (2H, m). 13C NMR
(100.6 MHz, CDCl3) d 13.7, 22.5, 34.6, 36.0, 62.1, 127.2,
130.0, 133.6, 133.7. EI-MS m/z: 140 [M]C. Anal. Calcd for
C9H16O: C, 77.09; H, 11.50. Found: C, 77.16; H, 11.63. To a
solution of this dienyl alcohol (701 mg, 5.0 mmol) in
CH2Cl2 (10 mL), acryloyl chloride (0.45 mL, 5.5 mmol)
and triethylamine (0.83 mL, 6.0 mmol) were added at 0 8C.
After being stirred at room temperature for 2.5 h, the
reaction mixture was quenched by H2O and extracted with
Et2O (10 mL!3). The organic layer was washed with brine
and dried over MgSO4. Purification by column chromato-
graphy on silica gel (hexane/Et2OZ50:1) gave the product
1
(neat) n cmK1; 1732. H NMR (400 MHz, CDCl3) d 1.02
(3H, d, JZ7.1 Hz), 1.38 (1H, ddd, JZ12.7, 10.3, 10.2 Hz),
1.67–1.80 (1H m), 1.81–1.89 (1H, m), 2.10 (1H, dt, JZ12.7,
4.3 Hz), 2.24–2.37 (1H, m), 2.47–2.58 (1H, m), 2.77–2.86
(1H, m), 4.26 (1H, td, JZ11.5, 3.3 Hz), 4.41 (1H, ddd, JZ
11.5, 4.6, 2.8 Hz), 5.53–5.58 (1H, m), 5.64 (1H, bd, JZ
10.0 Hz). 13C NMR (100.6 MHz, CDCl3) d 21.2, 27.3, 30.7,
32.2, 32.4, 40.2, 69.2, 126.9, 134.8, 174.1. EI-MS m/z: 166
[M]C. Anal. Calcd for C10H14O2: C, 72.26; H, 8.49. Found:
C, 72.16; H, 8.20.
The cycloadducts 2a–d, 2h12a,b and 2i19 were reported
previously.
4.3.1. (4aS*,7S*,8aR*)-7-Propyl-3,4,4a,7,8,8a-hexa-
hydro-1H-isochromen-1-one (2f). Yield 18%. Colorless
1
crystals. Mp 31–32 8C. IR (KBr) n cmK1; 1731. H NMR
(400 MHz, CDCl3) d 0.91 (3H, t, JZ6.7 Hz), 1.19–1.46
(6H, m), 1.67–1.80 (1H, m), 1.81–1.89 (1H, m), 2.08–2.26
(2H, m), 2.49–2.59 (1H, m), 2.67–2.76 (1H, m), 4.27 (1H,
td, JZ11.6, 3.3 Hz), 4.41 (1H, ddd, JZ11.6, 4.6, 2.5 Hz),
5.58 (1H, ddd, JZ10.0, 4.2, 2.5 Hz), 5.68 (1H, bd, JZ
10.0 Hz). 13C NMR (100.6 MHz, CDCl3) d 14.1, 19.7,
27.3, 30.1, 32.8, 35.4, 38.1, 40.1, 69.2, 127.1, 133.7, 174.3.
ESI-MS m/z: 195 [MCH]C. HRMS Calcd for C12H19O2
[MCH]C: 195.1385, Found: 195.1402.
1
1f (93% yield). Colorless oil. IR (neat) n cmK1; 1727. H
NMR (400 MHz, CDCl3) d 0.91 (3H, t, JZ7.4 Hz), 1.42
(2H, qt, JZ7.4, 7.2 Hz), 2.04 (2H, q, JZ7.2 Hz), 2.43 (2H,
q, JZ6.9 Hz), 4.19 (2H, t, JZ6.9 Hz), 5.49–5.67 (2H, m),
5.82 (1H, dd, JZ10.4, 1.5 Hz), 5.97–6.15 (2H, m), 6.12
(1H, dd, JZ17.3, 10.4 Hz), 6.40 (1H, dd, JZ17.3, 1.5 Hz).
13C NMR (100.6 MHz, CDCl3) d 13.7, 22.5, 31.9, 34.7,
63.9, 126.3, 128.5, 130.1, 130.6, 133.1, 133.7, 166.2. ESI-

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H. Yanai et al. / Tetrahedron 61 (2005) 7087–7093
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Iimura, S.; Manabe, K.; Kobayashi, S. Tetrahedron 2004, 60,
7673.
4.3.2. (4aS*,8R*,8aS*)-1-Oxo-3,4,4a,7,8,8a-hexahydro-
1H-isochromene-8-carboxylic acid (2g). Yield 78%.
Colorless crystals. Mp 177–178 8C. IR (KBr) n cmK1
;
3023, 1734, 1709, 946. 1H NMR (400 MHz, CDCl3) d 1.70–
1.81 (1H, m), 2.18–2.29 (1H, m), 2.30–2.53 (2H, m), 2.62–
2.72 (1H, m), 2.96 (1H, bs), 3.41–3.49 (1H, m), 4.16–4.25
(1H, m), 4.26–4.35 (1H, m), 5.54 (1H, bd, JZ10.0 Hz),
5.79–5.88 (1H, m), 11.2 (1H, bs, CO2H). 13C NMR
(100.6 MHz, CDCl3) d 22.9, 28.5, 32.6, 40.1, 40.9, 66.3,
128.0, 128.2, 171.5, 178.7. ESI-MS m/z: 197 [MCH]C.
HRMS Calcd for C10H13O4 [MCH]C: 197.0814, Found:
197.0810. Anal. Calcd for C10H12O4: C, 61.22; H, 6.16.
Found: C, 61.01; H, 6.19.
4. For recent examples, see: (a) Loh, T.-P.; Pei, J.; Lin, M. Chem.
Commun. 1996, 2315. (b) Otto, S.; Engberts, J. B. F. N. J. Am.
Chem. Soc. 1999, 121, 6798. (c) Amantini, D.; Fringuelli, F.;
Piermatti, O.; Pizzo, F.; Vaccaro, L. J. Org. Chem. 2003, 68,
9263.
5. Reviews on Pd-catalyzed cross coupling reactions in water,
see: (a) Pierre Genet, J.; Savignac, M. J. Organometal. Chem.
1999, 576, 305. (b) Beletskaya, I. P.; Cheprakov, A. V. In
Negishi, E., Ed.; Handbook of organopalladium chemistry for
organic synthesis; Wiley: New York, 2002; Vol. 2,
pp 2957–3006. (c) Uozumi, Y. J. Synth. Org. Chem., Jpn.
2002, 60, 1063.
4.4. Recycling procedure of In(OTf)3: IMDA reaction of
1-methyl-3,5-hexadienyl acrylate (1d)
6. Recent examples, see: (a) Morin Deveau, A.; MacDonald,
T. L. Tetrahedron Lett. 2004, 45, 803. (b) Wolf, C.; Lerebours,
R. Org. Lett. 2004, 6, 1147. (c) Friesen, R. W.; Trimble, L. A.
Can. J. Chem. 2004, 82, 206. (d) DeVasher, R. B.; Moore,
L. R.; Shaughnessy, K. H. J. Org. Chem. 2004, 69, 7919.
7. For reviews on synthetic utility of lanthanoid triflates, see: (a)
Kobayashi, S.; Ishitani, H. J. Synth. Org. Chem., Jpn. 1998, 56,
357. (b) Kobayashi, S. In Yamamoto, H., Ed.; Lewis Acids in
Organic Synthesis; Wiley: Weinheim, Germany, 2000; Vol. 2,
pp 883–910. (c) Kobayashi, S.; Sugiura, M.; Kitagawa, H.;
Lam, W. W.-L. Chem. Rev. 2002, 102, 2227.
To a solution of indium(III) triflate (56 mg, 0.1 mmol) in
H2O (6.0 mL), a solution of 1,7,9-decatrienoate 1d (83 mg,
0.5 mmol) in 2-propanol (1.0 mL) was added at room
temperature, and then the whole was stirred at 70 8C for
12 h. When the consumption of 1d was confirmed by
monitoring the reaction mixture by TLC, the reaction
mixture was carefully extracted with Et2O (5 mL!2).
Usual work-up of the organic extracts (washed with brine,
dried over MgSO4 and evaporated) and purification by
column chromatography gave the cycloadduct 2d (68.7 mg,
83% yield). To the aqueous layer (ca. 6 mL), a solution of
substrate 1d (83 mg, 0.5 mmol) in 2-propanol (1.0 mL) was
added and the mixture was stirred under the similar
conditions for the first run. After extractive work-up and
purification by column chromatography on silica gel, the
organic phase gave the product 2d (64.7 mg, 78% yield). In
a similar manner, the resulting aqueous layer was used for
the third reaction (1d; 83 mg, 0.5 mmol) to obtain 2d
(65.3 mg) in 79% yield.
8. For some examples, see: (a) Kobayashi, S.; Iwamoto, S.;
Nagayama, S. Synlett 1997, 1099. (b) Nagayama, S.;
Kobayashi, S. J. Am. Chem. Soc. 1997, 119, 10049. (c)
Kobayashi, S.; Busujima, T.; Nagayama, S. Chem. Commun.
1998, 19.
9. (a) Kobayashi, S.; Busujima, T.; Nagayama, S. Tetrahedron
Lett. 1998, 39, 1579. (b) Munoz-Muniz, O.; Quintanar-Audelo,
M.; Juaristi, E. J. Org. Chem. 2003, 68, 1622. (c) Ding, R.;
Zhang, H. B.; Chen, Y. J.; Liu, L.; Wang, D.; Li, C. J. Synlett
2004, 555.
10. For a review on conformation and stereoelectronic effect of
ester compounds, see: Deslongchamps, P. Stereoelectric
Effects in Organic Chemistry; Pergamon: Oxford, 1983; pp
54–100.
References and notes
11. Cain, D.; Pawar, D. M.; Stewart, M.; Billings, H., Jr.; Noe,
E. A. J. Org. Chem. 2001, 66, 6092.
1. For reviews, see: (a) Li, C. Chem. Rev. 1993, 93, 2023. (b)
Lubineau, A. Chem. Ind. 1996, 123. (c) Engberts, J. B. N.;
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1996, 115, 457. (d) Cornils, B.; Herrmann, W. A.; Eckl, R. W.
J. Mol. Catal., A 1997, 116, 27. (e) Li, C.; Chen, T.-H. Organic
Synthesis in Water; Wiley: New York, 1997. (f) Grieco, P. A.
Organic Reaction in Aqueous Media; Blackie Academic and
Professinal: London, 1998.
12. For examples of IMDA reaction, see: (a) Saito, A.; Ito, H.;
Taguchi, T. Org. Lett. 2002, 4, 4619. (b) Saito, A.; Yanai, H.;
Taguchi, T. Tetrahedron 2004, 60, 12239.(c) Saito, A.; Yanai,
H.; Sakamoto, W.; Takahashi, K.; Taguchi, T. J. Fluorine
Chem. 2005, 126, 709.
13. For example of intermolecular version, see: Saito, A.; Yanai,
H.; Taguchi, T. Tetrahedron Lett. 2004, 45, 9439.
14. (a) Jung, M. E.; Gervay, J. J. Am. Chem. Soc. 1989, 111, 5469.
(b) Jung, M. E. Synlett 1990, 186. (c) Giessner-Prettre, C.;
Hu¨ckel, S.; Maddaluno, J.; Jung, M. E. J. Org. Chem. 1997, 62,
1439. (d) Jung, M. E. Synlett 1999, 843.
2. For recent examples of the allylation of carbonyl compounds
mediated by indium, see: (a) Tan, K.-T.; Chng, S.-S.; Cheng,
H.-S.; Loh, T.-P. J. Am. Chem. Soc. 2003, 125, 2958. (b)
Foubelo, F.; Yus, M. Tetrahedron: Asymmetry 2004, 15, 3823.
Bismuth mediated reactions, see: (c) Smith, K.; Lock, S.; El-
Hiti, G. A.; Wada, M.; Miyoshi, N. Org. Biomol. Chem. 2004,
2, 935. (d) Xu, X.; Zha, Z.; Miao, Q.; Wang, Z. Synlett 2004,
1171. Other metal salts mediated reactions, see: (e) Wang, Z.;
Yuan, S.; Li, C.-J. Tetrahedron Lett. 2002, 43, 5097. (f)
Fukuma, T.; Lock, S.; Miyoshi, N.; Wada, M. Chem. Lett.
2002, 376.
15. (a) Yorimitsu, H.; Nakamura, T.; Shinokubo, H.; Oshima, K.
J. Org. Chem. 1998, 63, 8604. (b) Yorimitsu, H.; Nakamura,
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J. Am. Chem. Soc. 2000, 122, 11041. (c) Yorimitsu, H.;
Shinokubo, H.; Oshima, K. Synlett 2002, 674.
16. The reaction of 6-hydroxy substrate 1h with TfN(AlMe2)2
resulted in decomposition of the substrate 1h.
3. For recent examples, see: (a) Tian, H.-Y.; Chen, Y.-J.; Wang,
D.; Bu, Y.-P.; Li, C.-J. Tetrahedron Lett. 2001, 42, 1803. (b)
17. We have already reported that stereoselective construction of
oxabicyclo[4.3.0]nonene derivatives was achieved by the

H. Yanai et al. / Tetrahedron 61 (2005) 7087–7093
7093
IMDA reaction of 6-silyloxy derivative followed by the
desilylation reaction of the cycloadducts with fluoride ion. In
these cases, re-lactonization reactions also proceeded in
stereospecificic manner. See, Ref. 12b.
19. Martin, S. F.; Williamson, S. A.; Gist, R. P.; Smith, K. M.
J. Org. Chem. 1983, 48, 5170.
20. Page, P. C. B.; Vahedi, H.; Batchelor, K. J.; Hindley, S. J.;
Edgar, M.; Beswick, P. Synlett 2003, 1022.
21. Snider, B. B.; Phillips, G. B.; Cordova, R. J. Org. Chem. 1983,
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18. White, J. D.; Nolen, E. G., Jr.; Miller, C. H. J. Org. Chem.
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