Stereocontrolled construction of tricyclic furan and pyrrolyl derivatives via tungsten-mediated [3+2] cycloaddition and intramolecular Diels-Alder reaction

Article abstract of DOI:10.1055/s-2002-35230

Vinylpropargyl tungsten complexes were prepared to comprise a tethered unsaturated ester designed for intramolecular Diels-Alder reaction. Treatment of these vinylpropargyl tungsten complexes with aldehydes and imines in the presences of BF₃·OE

Full text of DOI:10.1055/s-2002-35230

FEATURE ARTICLE
2457
Stereocontrolled Construction of Tricyclic Furan and Pyrrolyl Derivatives
via Tungsten-Mediated [3+2] Cycloaddition and Intramolecular Diels–Alder
Reaction
S
tereocontrolled Constr
e
uction of Tr
n
icyclic Fura
-
L
rrolyl
D
erivativ
i
es Lin, B. Pratap Taduri, Rai-Shung Liu*
Chemistry Department, National Tsing-Hua University, Hsinchu, Taiwan, Republic of China
E-mail: rsliu@mx.nthu.edu.tw
Received 22 April 2002; revised 7 May 2002
Abstract: Vinylpropargyl tungsten complexes were prepared to
comprise a tethered unsaturated ester designed for intramolecular
Diels–Alder reaction. Treatment of these vinylpropargyl tungsten
complexes with aldehydes and imines in the presences of BF3 OEt2
resulted in a [3+2] cycloaddition to give 2,5-dihydrofuran and pyr-
role derivatives. Hydrodemetalation of these tungsten heterocyclic
compounds was achieved with Me3NO in CH3CN and the resulting
furyl and dihydropyrrolyl dienes undergo highly diastereoselective
intramolecular Diels–Alder reaction to give tricyclic furan and pyr-
rolyl derivatives efficiently. This method provides a short stereose-
lective synthesis of tricyclic furan and pyrrole derivatives.
Key words: tricyclic furans, [3+2] cycloaddition, intramolecular
Diels–Alder reaction
Furan and pyrrole are common functionalities in numer-
ous naturally occurring compounds.1 Scheme 1 shows
three tricyclic oxygen heterocycles A–C isolated from
different natural sources.2–4 These complex heterocyclic
Scheme 1
compounds show interesting biological activities which
are closely related to the lactone functionailty. Synthetic
Bu3SnH and I2. Subsequent transformation of these iodo
studies toward these molecules have attracted consider-
able attention.2–4 Previously, we reported a short stereo-
controlled synthesis of furyl dienes via [3+2]
cycloaddition of vinylpropargyltungsten complexes with
aldehyde in the presence of BF3 OEt2 [Scheme 1 (1)].5,6
These tungsten 2,5-dihydrofuran derivatives are prone to
hydrodemetalation upon oxidation, and the resulting free
dienes are good building blocks to construct different
framework of tricyclic furan derivatives via intermolecu-
lar Diels–Alder reactions.7 It provides a short pathway to
complex natural furans as represented by the drimane
families.8,9 In this study, we extend this synthetic ap-
proach to construct the framework of tricyclic furans as
represented by A–C. The key step involves tungsten-me-
diated [3+2] cycloaddition reaction and intramolecular
Diels–Alder reaction as shown in [Scheme 1 (2)]. This
synthetic method is also applicable to the stereocontrolled
construction of tricyclic pyrrole analogues.
derivatives into unsaturated esters 5, 6 was accomplished
via alkylation with methyl-4-chloro-2-2-butenolate. The
two steps proceeded in excellent yields (> 85%). Palladi-
um-catalyzed10 coupling of vinyl iodides 5, 6 with propar-
gyl alcohol produced 4-en-2-yn-1-ols 7, 8 efficiently
(yields > 82%). Treatment of these two alcohols with
SOCl2 afforded the desired propargyl chlorides 9, 10
quantitatively.
This synthetic protocol requires vinyl chloropropargyl de-
rivatives 9, 10 tethered with an unsaturated ester. As
shown in Scheme 2, alkynes 1,2 were smoothly converted
to vinyl iodides 3, 4 (85–87% yields) upon treatment with
Scheme 2
Synthesis 2002, No. 16, Print: 14 11 2002.
Art Id.1437-210X,E;2002,0,16,2457,2463,ftx,en;F03202SS.pdf.
© Georg Thieme Verlag Stuttgart · New York
ISSN 0039-7881

2458
W.-L. Lin et al.
FEATURE ARTICLE
The key compounds 11, 12 were prepared by metallation dienes 21, 22 were obtained in yields of 56% and 66% re-
5–7
of chloropropargyl species with NaCpW(CO)3
(2.0 spectively by Me3NO demetallation in CH3CN.
equiv) in cold THF (0 °C, 8 h). In the presence of
BF3 Et2 (1.0 equiv), the reaction of compounds 11, 12
with RCHO (R = Ph, Me2CH) produced the 2,5-dihydro-
furans 13–15 in yields exceeding 82%. This cycloaddition
shows migration of tungsten fragment from its CH2 car-
bon to the cental tertiary carbon. This phenomenon can be
Intramolecular Diels–Alder reaction of heterocyclic
dienes 16–18, 20, 21 were performed in hot toluene
(110 °C, 8–12 h), and only one stereoisomer was formed
1
exclusively according to H NMR spectra of crude sam-
ple. The cycloadducts 23–27 were obtained in 83–88%
yields after purification on a silica column. The structures
of 23–27 were determined based on the NOE spectra of
the representative products 23 and 24. In the case of com-
2
rationalised by a tungsten- -allene cationic intermediate
which is in accordance with previous investigations.11
Hydrodemetalation7 of furyltungsten complexes 13–15 pound 23, irradiation of the H3-proton ( 2.73) shows an
was achieved using Me3NO in CH3CN, affording func- intensity increase of the H2 ( 3.17) and H8 ( 2.09) reso-
tionalized furyl dienes 16–18 in reasonable yields 60– nances by 6.9% and 3.2% respectively whereas the reso-
70%. We also studied this cycloaddition on a pyrrole sys- nance of the H4 ( 1.77) remains unchanged. Similarly,
tem. Cyclization of compounds 11, 12 with PhCH=NTs in irradiation of the H1 proton ( 4.05) of 23 gives an inten-
the presence of BF3 OEt2 also proceeded smoothly, yield- sity increase of the H2 ( 3.17) proton by 3.9% but the H11
ing pyrrolyl analogues 19, 20 efficiently and free pyrrolyl proton ( 5.24) resonance remains unchanged. Irradiation
of the H1 proton ( 3.49) enhances the intensity of the H11
Biographical Sketches
Ms. Lin Wen-Li was born and MSc degree in chemis- National Tsing-Hua Univer-
in 1973 and received her try from Tsing-Hua Univer- sity.
BSc degree in chemistry in sity (1999). She is now
Tung-Hai University (1995) serving as a lecturer at the
Mr. Taduri, B. Pratap was versity (1997) and MSc de- search assistant at National
born in 1977 in India and re- gree in chemistry from Tsing-Hua University.
ceived his BSc degree in Osmania University (1999).
chemistry in Kakatiya Uni- He is now working as a re-
Dr. Rai-Shung Liu is cur- search at Texas A&M Uni- Chair Fellow from Educa-
rently a professor of Nation- versity (1981–1982). He tion Minister (2002). His re-
al Tsing-Hua University at started his academic career search interest includes
Hsinchu, Taiwan. He was at Chemistry Department, development of new syn-
born in 1954 and received National Tsing-Hua Univer- thetic methods using metal-
his BSc Degree from Na- sity in 1982 and promoted to mediated or metal-catalyzed
tional Tsing- Hua Universi- professor in 1987. He has reactions. He has published
ty. He later went to United obtained several important over 100 scientific papers
States to obtain his PhD de- awards in Taiwan including and four review articles in
gree from Columbia Uni- Academic Award of Sci- this area.
versity at New York in 1981 ence from Education Minis-
and did postdoctoral re- ter (1999), and National
Synthesis 2002, No. 16, 2457–2463 ISSN 0039-7881 © Thieme Stuttgart · New York

FEATURE ARTICLE
Stereocontrolled Construction of Tricyclic Furan and Pyrrolyl Derivatives
2459
Intramolecular Diels–Alder reaction has been studied ex-
tensively,12,13 and cis- trans- stereoselection of products
depend on both electronic and steric effects. Figure 1
shows two transition states D and E for trans- and cis-ste-
reoselection for decatriene according to the Houk’s con-
cept of twist asynchronicity (Figure 1).12 According to
this concept, stereoselection is controlled by the timing of
bond formation in the transition state. A generally accept-
ed interpretation is that the terminally CO2Me group on
decatriene prefers trans-fused structure because of the po-
larization effect of the double bond, which enhances the
interactions of C(2)-C(7) carbons. Approach of the C2=C1
bond of state D to furyl diene preferably proceeds on the
opposite side of the phenyl group to minimize steric inter-
action, and this model can fully account for the observed
structure of compound 25. In state E, an additional steric
interaction between the axial ester and C7=C8 bond disfa-
vors the cis-stereoselection.
E
E
Ph
Ph
5
5
2
2
7
E
7
E
O
O
Scheme 3
E
E
D (E = CO2Me)
E (E = CO2Me)
trans-fused
cis-fused
proton ( 5.24) by 2.0% and the H2 ( 3.17) signal shows
a small increase (1.0%). This information reveals that H3-
proton is cis to both H2 and H8-proton, and trans to the H4-
proton, whereas the H11 proton is trans to the C2-prroton.
Assignment of the structure 25 is also made based on anal-
ogous NOE 1H NMR experiments.
Figure 1
In summary, stereocontrolled synthesis of tricyclic furan
and pyrrole compounds has been developed based on
tungsten-mediated [3+2] cycloaddition and intramolecu-
lar Diels–Alder reaction. The stereochemistry of the [4+2]
cycloadduct is elucidated and subsequently rationalized
based on a suitable model. This new synthetic approach
provides a short pathway to construct framework of tricy-
clic furans such as himgravine B.
Table 1 Reaction Conditions and Products of Diels–Alder Reaction
Reactants
Conditions
110 °C, 8 h
Products
16
Unless otherwise noted, all reactions were carried out under a nitro-
gen atmosphere in oven-dried glassware using standard syringe,
cannula and septa apparatus. Benzene, Et2O, THF and hexane were
dried with sodium benzophenone and distilled before use. CH2Cl2
was dried over CaH2 and distilled before use. NaCpW(CO)3 was
prepared according to our preceding papers. All peaks given for IR
spectroscopy correspond to carbonyl stretch. HRMS was carried out
in CI mode unless otherwise stated.
17
110 °C, 8 h
18
21
110 °C, 12 h
110 °C, 8 h
Dimethyl-2-[(E)-iodo-2-proprenyl]malonate (3)
To compound 1 (5.0 g, 29.4 mmol) and AIBN (0.056 g, 0.342
mmol) was added Bu3SnH (8.7 mL, 32.4 mmol), and the mixture
was heated at 130 °C for 3 h. To this mixture was added a solution
of I2 (8.22 g, 32.4 mmol) in Et2O (20 mL), and the mixture was
stirred for 3 h before addition of Na2S2O5 5H2O (20 g, 80.9 mmol)
and KF (11.24 g, 0.19 mmol). This white suspension was stirred for
12 h at 23 °C , filtered, the organic layer was extracted with Et2O,
dried over MgSO4, concentrated and purified by column chroma-
tography (silica, Et2O–hexane, 1:1) to yield 3 as a colorless oil (7.6
g, 87%).
22
110 °C, 12 h
IR (neat): 1731 cm–1.
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2460
W.-L. Lin et al.
FEATURE ARTICLE
1H NMR (400 MHz, CDCl3): = 6.54 (1 H, dt, J = 14.4, 7.4 Hz),
6.18 (1 H, d, J = 14.4 Hz), 3.72 (6 H, s), 3.43 (1 H, t, J = 7.5 Hz),
2.60 (2 H, t, J = 7.4 Hz).
trated, a solution of NaCl (20 mL) was added and the product was
extracted with Et2O, concentrated and purified by column chroma-
tography (silica) to yield 7 as a colorless oil (3.1 g, 85%).
13C NMR (75 MHz, CDCl3): = 168.8, 168.6, 141.2, 136.6, 78.3,
52.6, 50.5, 34.8.
MS (75 eV, EI): m/z = 298 (M+).
IR (neat): 1727 cm–1.
1H NMR (400 MHz, CDCl3): = 6.54 (1 H, dt, J = 15.2, 8.0 Hz),
5.80 (1 H, dt, J = 15.6, 7.6 Hz), 5.69 (1 H, d, J = 15.2 Hz), 5.40 (1
H, d, J = 15.6 Hz), 4.07 (2 H, s), 3.56 (9 H, 3 s), 2.55 (2 H, d, J = 8.0
Hz), 2.49 (2 H, d, J = 7.6 Hz).
HRMS (EI): m/z calcd for C8H11IO4: 297.9702; found: 297.9709.
Dimethyl-2-[(E)-iodo-3-butenenyl]malonate (4)
Compound 2 (2.50 g), Bu3SnH, AIBN and I2 were reacted accord-
ing to the procedure described for 3 to give 4 as a colorless oil
(3.59g, 85% yield).
13C NMR (75 MHz, CDCl3): = 169.7, 165.5, 141.7, 138.4, 124.5,
112.8, 83.6, 83.5, 56.6, 52.3, 51.0, 36.1, 35.1, 30.5.
HRMS (EI): m/z calcd for C16H20O7: 324.0870; found: 324.0868.
IR (neat): 1751, 1734 cm–1.
Trimethyl (1E,7E)-11-Hydroxy-1,7-undecadie-9-yne-1,4,4-tri-
carboxylate (8)
Compound 6 (2.50 g), PdCl2(PPh3)2, CuI, and propargyl alcohol
were reacted according to the procedure described for 7 to give 8 as
a colorless oil (1.71 g, 82%).
1H NMR (400 MHz, CDCl3): = 6.43 (1 H, dt, J = 13.4, 7.0 Hz),
6.04 (1 H, dd, J = 13.4, 1.2 Hz), 3.71 (6 H, s), 3.33 (1 H, t, J = 7.2
Hz), 1.97–2.11 (4 H, m).
13C NMR (300 MHz, CDCl3): = 169.4, 144.3, 139.3, 84.0, 52.6,
50.6, 33.5, 27.2.
IR (neat): 1729 cm–1.
1H NMR (400 MHz, CDCl3): = 6.72 (1 H, dt, J = 15.6, 7.7 Hz),
6.02 (1 H, dt, J = 15.8, 6.8 Hz), 5.85 (1 H, d, J = 15.6 Hz), 5.47 (1
H, d, J = 15.8 Hz), 4.32 (2 H, s), 3.71 (9 H, 3 s), 2.75 (2 H, d, J = 7.7
Hz), 2.24 (1 H, br s), 2.00 (2 H, m), 1.93 (2 H, m).
13C NMR (75 MHz, CDCl3): 170.7, 166.2, 142.9, 142.4, 124.7,
110.1, 86.6, 83.7, 56.8, 52.7, 51.6, 51.3, 35.7, 31.8, 27.7.
MS (75 eV, EI): m/z = 312 (M+).
HRMS (EI): m/z calcd for C9H13IO4: 311.9858; found: 311.9856.
Trimethyl (1E,6E)-7-Iodo-1,6-heptadiene-1,4,4-tricarboxylate
(5)
To a solution of compound 3 (2.5 g, 8.3 mmol) in THF (90 mL) was
added NaH (0.20 g, 8.3 mmol), and the solution was stirred for 1 h
at 0 °C. To the resulting solution was added slowly 4-chloro-2-
butenolate (1.23 g, 9.1 mmol) at 23 °C, and the solution was stirred
until TLC showed the completion of the reaction. To this solution
was added NH4Cl, and the organic material was extracted with Et2O
and concentrated to afford 5 as a colorless oil (3.10 g, 95%).
HRMS (EI): m/z calcd for C17H22O7: 338.1366, found: 338.1364.
Trimethyl (1E,6E)-10-Chloro-1,6-decadien-8-yne-1,4,4-tricar-
boxylate (9)
To a solution of compound 7 (3.00 g, 9.26 mmol) in Et2O (20 mL)
was added HMPA (10 mL), then SO2Cl (0.81 mL, 11.1 mmol) was
added dropwise at 0 °C. The mixture was stirred for 6 h at 23 °C be-
fore then neutralized with a NaHCO3 solution. The organic layer
was extracted with Et2O, dried over MgSO4, concentrated and puri-
fied by column chromatography (silica, Et2O–hexane, 1:1) to yield
9 as a colorless oil (3.16 g, 9.24 mmol, 98%).
IR (neat): 1731 cm–1.
1H NMR (400 MHz, CDCl3): = 6.67 (1 H, dt, J = 15.8, 7.4 Hz),
6.31 (1 H, J = 14.2, 7.5 Hz), 6.13 (1 H, d, J = 15.8 Hz); 5.81 (1 H,
d, J = 15.8 Hz), 3.66 (9 H, 3 s), 2.71 (2 H, dd, J = 7.4, 4.4 Hz), 2.55
(2 H, d, J = 7.5 Hz).
13C NMR (75 MHz, CDCl3): = 169.9, 165.9, 141.9, 139.5, 134.9,
124.9, 52.7, 51.4, 39.4, 35.5.
IR (neat): 1733 cm–1.
1H NMR (400 MHz, CDCl3): = 6.64 (1 H, dt, J = 15.2, 8.0 Hz),
5.80 (1 H, dt, J = 15.6, 7.5 Hz), 5.69 (1 H, d, J = 15.2 Hz), 5.40 (1
H, d, J = 15.6 Hz), 4.07 (2 H, s), 3.56 (9 H, 3 s), 2.55 (2 H, d, J = 8.0
Hz), 2.49 (2 H, d, J = 7.6 Hz).
MS (75 eV): m/z = 396 (M+).
HRMS (EI): m/z calcd for C13H17IO4: 396.0070; found: 396.0080.
13C NMR (100 MHz, CDCl3): = 169.7, 165.5, 141.7, 138.4, 124.5,
112.8, 83.6, 83.5, 56.6, 52.3, 51.0, 36.1, 35.1, 30.5.
Trimethyl (1E,7E)-8-Iodo-1,7-octadiene-1,4,4-tricarboxylate
(6)
Compound 4 (2.50 g), NaH and 4-chloro-2-butenolate were reacted
according to the procedure described for 5 to give 6 as a colorless
oil (3.0 g, 92%).
HRMS (EI): m/z calcd for C16H19ClO6: 342.0870; found: 342.0868.
Trimethyl (1E,7E)-11-Chloro-1,7-undecadien-9-yne-1,4,4-tri-
carboxylate (10)
Compound 8 (1.50 g), HMPA, SO2Cl were reacted according to the
procedure described for 9 to give 10 as a colorless oil (1.28 g, 82%).
IR (neat): 1733 cm–1.
1H NMR (400 MHz, CDCl3): = 6.69 (1 H, dt, J = 15.7, 7.1 Hz),
6.38 (1 H, dd, J = 14,3, 4.0 Hz), 6.01 (1 H, d, J = 14.3 Hz), 5.82 (1
H, d, J = 15.7 Hz), 3.69 (9 H, 3 s), 1.93 (4H, m).
13C NMR (75 MHz, CDCl3): = 170.5, 170.4, 160.6, 144.2, 142.1,
139.9, 124.7, 56.5, 52.6, 51.4, 35.5, 31.2, 30.6.
IR (neat): 1733 cm–1.
1H NMR (400 MHz, CDCl3): = 6.71 (1 H, dt, J = 16.0, 6.9 Hz),
6.07 (1 H, dt, J = 16.0, 6.7 Hz), 5.84 (1 H, d, J = 16.0 Hz), 5.48 (1
H, d, J = 16.0 Hz), 4.32 (2 H, br s), 3.70 (9 H, 3s), 2.74 (2 H, d,
J = 7.9 Hz), 1.90–2.05 (4 H, m).
MS (75 eV): m/z = 410 (M+).
13C NMR (100 MHz, CDCl3): = 170.5, 165.8, 144.0, 142.2, 124.6,
109.5, 84.4, 82.8, 56.6, 52.5, 51.3, 35.5, 31.5, 30.0, 27.5.
HRMS (EI): m/z calcd for C13H19IO6: 398.0026; found: 398.0022.
Trimethyl (1E, 6E)-10-Hydroxy-1,6-decadie-8-yne-1,4,4-tricar-
boxylate (7)
HRMS (EI): m/z calcd for C17H21ClO6: 356.1027; found: 356.1025.
To a solution of PdCl2(PPh3)2 (90 mg, 0.11 mmol) and CuI (40 mg,
0.22 mmol) in Et2NH (50 mL) was added propargyl alcohol (0.65
mL, 11.1 mmol) and compound 5 (4.4 g, 11.1 mmol) at 0 °C, and
the mixture was stirred for 8 h at 23 °C. The solution was concen-
Vinylpropargyl Tungsten Complex 11
To a solution of [CpW(CO)3]2 (1.94 g, 2.92 mmol) in THF (20 mL)
was added Na/Hg (10 g, 5 wt%), and the solution was stirred for 8
h. It was then slowly added to propargyl chloride 9 (1.00 g, 2.92
Synthesis 2002, No. 16, 2457–2463 ISSN 0039-7881 © Thieme Stuttgart · New York

FEATURE ARTICLE
Stereocontrolled Construction of Tricyclic Furan and Pyrrolyl Derivatives
2461
mmol) at 0 °C, and the mixture was stirred for 6 h before the solvent
was evaporated under reduced pressure. The residues were extract-
ed with Et2O and purified by column chromatography (silica, Et2O–
hexane, 1:1) to yield 11 as a colorless oil (1.07 g, 92%).
Hz), 3.65 (3 H, s), 3.64 (3 H, s),, 3.62 (3 H, s), 2.62–2.75 (4 H, m),
1.94 (1 H, m), 0.95 (3 H, d, J = 7.1 Hz), 0.56 (3 H, d, J = 7.1 Hz).
13C NMR (75 MHz, CDCl3): = 226.1, 215.8, 214.6, 170.6, 166.1,
145.5, 142.7, 132.2, 124.6, 123.2, 122.3, 90.9, 89.9, 89.7, 57.7,
52.5, 51.3, 37.6, 35.4, 31.8, 20.8, 14.4.
IR (neat): 2015, 1915, 1731 cm–1.
1H NMR (300 MHz, CDCl3): = 6.73 (1 H, dt, J = 15.5, 7.7 Hz),
5.84 (1 H, d, J = 15.5 Hz), 5.70–5.52 (2 H, m), 5.45 (5 H, s), 3.69 (3
H, s), 3.68 (3 H, s), 3.67 (3 H, s), 2.72 (2 H, d, J = 7.7 Hz), 2.63 (2
H, d, J = 7.0 Hz), 2.04 (2 H, br s).
MS (EI, 75 eV): m/z = 712 (M+).
Anal. Calcd for C28H32WO10: C, 47.21; H, 4.53. Found: 47.23; H,
4.56.
13C NMR (75 MHz, CDCl3): 228.8, 216.4, 170.5, 170.3, 166.1,
142.4, 132.6, 124.7, 115.8, 100.3, 92.5, 79.1, 57.3, 52.6, 51.4, 36.5,
35.4, –31.8.
Tungsten- 1-2,5-dihydrofuryl Complex 15
Compound 12 (2.0 g), aldehyde and BF3 OEt2 were reacted accord-
ing to the procedure described for 13 to give 15 as a yellow solid
(1.9 g, 83%).
MS (EI, 72 eV): m/z = 640 (M+).
IR (neat): 2022, 1937, 1731 cm–1.
Anal. Calcd for C24H24WO9: C, 44.99; H, 3.78. Found: C, 45.86; H,
4.01.
1H NMR (300 MHz, CDCl3): = 7.27–7.14 (5 H, m), 6.69 (1 H, dt,
J = 16.0, 8.0 Hz), 5.92 (1 H, d, J = 16.2 Hz), 5.79 (1 H, d, J = 16.0
Hz), 5.59 (1 H, s), 5.58 (5 H, s), 5.10 (1 H, dt, J = 16.0, 6.0 Hz), 4.67
(1 H, dd J = 16.0, 4.0 HZ), 4.54 (1 H, d, J = 12.7 Hz), 3.67 (3 H, s),
3.65 (3 H, s), 3.64 (3 H, s), 2.67 (2 H, m), 1.88 (2 H, m), 1.75 (2 H,
m).
Vinylpropargyl Tungsten Complex 12
Compound 10 (1.0 g), [CpW(CO)3]2 and Na/Hg were reacted ac-
cording to the procedure described for 11 to give 12 as a yellow oil
(1.5 g, 82%).
IR (neat): 2015 (CO, vs), 1915 (CO, vs), 1731 cm-1 (CO, s).
13C NMR (100 MHz, CDCl3): = 226.5, 215.5, 214.2, 121.6, 91.1,
89.0, 88.0, 57.1, 52,5, 51.5, 35.7, 32.6, 28.4;
1H NMR (300 MHz, CDCl3): = 6.72 (1 H, dt, J = 16.0, 7.7 Hz),
5.84 (1 H, d, J = 6.5 Hz), 5.77 (1 H, dt, J = 16.0, 7.0 Hz), 5.48 (1 H,
dt, J = 16.0, 6.5 Hz), 5.43 (5 H, s), 3.69 (3 H, s), 3.68 (3 H, s), 3.67
(3 H, s), 2.74 (2 H, d, J = 7.0 Hz), 2.03 (2 H, br s, J = 2.4 Hz), 1.90–
1.96 (4 H, m). 13C NMR (75 MHz, CDCl3): = 229.5, 216.5, 170.9,
170.8, 168.1, 142.5, 138.6, 124.6, 112.1, 105.2, 99.1, 92.6, 56.9,
52.6, 51.5, 35.3, 32.0, 27.5, –31.6.
Anal. Calcd for C32H32WO10: C, 50.54; H, 4.24. Found: C, 50.56; H,
4.21.
Trimethyl (1E,6E)-7-(2-Phenyl-2,5-dihydro-3-furanyl)-1,6-
heptadiene-1,4,4-tricarboxylate (16)
To anhyd Me3NO (0.50 g, 6.7 mmol) and furyltungsten complex 13
(1.00 g, 1.34 mmol) was added CH3CN (5 mL) and the solution was
stirred at 23 °C for 8 h. To this red solution was added excess Et2O
to precipitate unreacted Me3NO, and the solution was filtered, con-
centrated and purified by preparative TLC to give diene 16 as a col-
orless oil (0.50 g, 66%).
MS (EI, 72 eV): m/z = 654 (M+).
Anal. Calcd for C25H26WO9: C, 44.99; H, 3.78. Found: C,45.86; H,
4.01.
Tungsten- 1-2,5-dihydrofuryl Complex 13
IR (neat): 1732 cm–1.
To a solution of compound 11 (2.00 g, 3.13 mmol) in CH2Cl2 (20
mL) was added benzaldehyde (0.38 mmol, 3.76 mmol) and
BF3 OEt2 (0.77 mL, 6.25 mmol) at –30 °C, the solution was stirred
for 5 h, and then warmed to 23 °C. To this solution was added a
NaHCO3 solution, and the organic material was extracted with
Et2O, dried over MgSO4 and purified by column chromatography
(silica) to yield 13 (2.20 g, 83%) as a colorless oil.
1H NMR (400 MHz, CDCl3): = 7.29–7.20 (5 H, m), 6.64 (1 H, dt,
J = 15.6, 7.8 Hz), 6.03 (1 H, d, J = 16 Hz), 5.91 (1 H, s), 5.75 (1 H,
d, J = 15.6 Hz), 5.66 (1 H, d, J = 2.3 Hz), 5.19 (1 H, dt, J = 16.0, 5.6
Hz), 4.76 (1 H, dd, J = 14.0, 2.3 Hz), 4.64 (1 H, d, J = 14 Hz), 3.63
(9 H, 3 s), 2.63 (2 H, d, J = 7.8 Hz), 1.75 (4 H, m).
13C NMR (100 MHz, CDCl3): = 170.7, 166.2, 142.4, 140.9, 139.5,
132.3, 128.4, 128.1, 127.4, 124.6, 124.5, 123.1, 78.7, 74.6, 56.9,
52.5, 51.5, 35.6, 32.0, 27.6.
IR (neat): 2020, 1935, 1729 cm–1.
1H NMR (300 MHz, CDCl3): = 7.37–7.13 (5 H, m, Ph), 6.61 (1 H,
dt, J = 15.9, 7.7 Hz), 5.97 (1 H, d, J = 15.9 Hz), 5.65–5.52 (7 H, m,
s), 4.92 (1 H, dt, J = 15.8. 7.1 Hz), 4.70 (1 H, dd, J = 12.7, 4.4 Hz),
4.56 (1 H, d, J = 12.7 Hz), 3.66 (3 H, s), 3.58 (3 H, s),, 3.55 (3 H, s),
2.67–2.46 (2 H, m), 2.29 (2 H, d, J = 7.7 Hz).
13C NMR (75 MHz, CDCl3): = 226.1. 215.5, 214.7, 170.4, 166.3,
144.9, 142.8, 142.7, 131.2, 128.5, 127.8, 127.6, 125.6, 124.4, 91.0,
89.2, 88.1, 87.4, 52.1, 51.4, 37.1, 34.8; Mass (72 eV, EI): m/z = 746
(M+).
MS (EI, 75 eV): m/z = 428.
HRMS (EI): m/z calcd for C23H26O7: 414.1678; found: 414.1668.
Trimethyl-1-(1E,6E)-7-(2-isopropyl)-2,5-dihydro-3-furanyl)-
1,6-heptadiene-1,4,4-tricarboxylate (17)
Compound 14 (1.0 g), Me3NO and CH3CN were reacted according
to the procedure described for 16 to give 17 as a colorless oil (0.32
g, 60%).
Anal. Calcd for C31H30WO10: C, 49.88; H, 4.05. Found: C, 49.90; H,
4.15.
IR (neat): 1729 cm–1.
1H NMR (300 MHz, CDCl3): = 6.76 (1 H, dt, J = 15.8, 7.4 Hz),
6.12 (1 H, d, J = 15.8 Hz), 5.84 (1 H, d, J = 15.5 Hz), 5.78 (1 H, s),
5.42 (1 H, dt, J = 15.5, 6.6 Hz), 4.81 (1 H, s), 4.60 (2 H, s), 3.70 (9
H, 3 s), 2.73 (2 H, d, J = 7.4 Hz), 2.65 (2 H, J = 6.6 Hz), 1.89 (1 H,
m), 1.04, 0.70 (6 H, 2 s).
13C NMR (75 MHz, CDCl3): = 170.5, 166.2, 142.5, 139.1, 127.5,
124.9, 122.1, 89.4, 75.2, 57.6, 52.7, 51.6, 37.0, 35.8, 31.4, 20.0,
14.5.
Tungsten- 1-2,5-dihydrofuryl Complex 14
Compound 11 (2.00 g), aldehyde and BF3 OEt2 were reacted ac-
cording to the procedure described for 13 to give 14 as a yellow oil
(1.08 g, 82%).
IR (neat): 2022, 1937, 1731 cm–1.
1H NMR (300 MHz, CDCl3): = 6.75 (1 H, dt, J = 15.9, 7.7 Hz),
5.97 (1 H, d, J = 15.9 Hz), 5.81 (1 H, d, J = 14.9 Hz), 5.52 (5 H, s),
5.21 (1 H, dt, J = 14.9, 7.7 Hz), 4.68 (1 H, s), 4.43 (1 H, d, J = 4.4
HRMS (EI): m/z calcd for C20H28O7: 380.1835; found: 380.1833.
Synthesis 2002, No. 16, 2457–2463 ISSN 0039-7881 © Thieme Stuttgart · New York

2462
W.-L. Lin et al.
FEATURE ARTICLE
Trimethyl-1-(1E,7E)-8-(2-phenyl)-2,5-dihydro-3-furanyl)-1,7-
octadiene-1,4,4-tricarboxylate (18)
4.15 (1 H, dd, J = 15.6, 4.8 Hz), 3.65 (s, 6 H), 3.55 (3 H, s), 2.50–
2.14 (4 H, m), 2.28 (3 H, s).
Compound 15 (1.0 g), Me3NO and CH3CN were reacted according
to the procedure described for 16 to give 18 as a colorless oil (0.39
g, 70%).
IR (neat): 2022, 1940, 1730 cm–1.
1H NMR (400 MHz, CDCl3): = 7.29–7.20 (5 H, m), 6.64 (1 H, dt,
J = 15.6, 7.8 Hz), 6.03 (1 H, d, J = 16 Hz), 5.91 (1 H, s), 5.75 (1 H,
d, J = 15.6 Hz), 5.66 (1 H, d, J = 2.3 Hz), 5.19 (1 H, dt, J = 16, 5.6
Hz), 4.76 (1 H, dd, J = 14.0, 2.3 Hz), 4.64 (1 H, d, J = 14.0 Hz), 3.63
(9 H, 3 s), 2.63 (2 H, d, J = 7.8 Hz), 1.75 (4 H, m).
13C NMR (100 MHz, CDCl3): = 170.7, 166.2, 142.4, 140.9, 139.5,
132.3, 128.4, 128.1, 127.4, 124.6, 124.5, 123.1, 48.7, 74.6, 56.9,
52.5, 51.5, 35.6, 32.0, 27.6.
13C NMR (75 MHz, CDCl3): = 170.2, 166.2, 142.8, 142.4, 140.0,
139.8, 129.3, 128.5, 128.0, 127.0, 126.7, 124.6, 123.0, 69.5, 57.1,
54.3, 52.6, 51.6, 36.4, 30.3, 21.4.
MS (EI, 75 eV): m/z = 567.
HRMS (EI): m/z calcd for C30H33SNO8: 567.1927; found:
567.1925.
Trimethyl (1E,7E)-8-{[1-(4-Methylphenyl)-sulfonyl]-2-phenyl-
2,5-dihydro-1H-3-pyrrolyl}-1,7-octadiene-1,4,4-tricarboxylate
(22)
Compound 20 (1.0 g, 1.09 mmol), Me3NO and CH3CN were reacted
according to the procedure described for 16 to give 22 as a colorless
oil (0.42 g, 66%).
HRMS (EI): m/z calcd for C24H28O7: 428.1835; found: 428.1838.
IR (neat): 1729 cm–1.
Tungsten- 1-2,5-dihydropyrrole Complex (19)
Complex 11 (2.0 g), PhCH=NTs and BF3 OEt2, were reacted ac-
cording to the procedure described for 13 to yield 19 as a yellow oil
(2.23 g, 80%).
1H NMR (400 MHz, CDCl3): = 7.30–7.03 (9 H, m), 6.62 (1 H, dt,
J = 16.0, 7.6 Hz), 5.82 (1 H, d, J = 16.0 Hz), 5.74 (1 H, d, J = 16.0
Hz), 5.66 (1 H, s), 5.51 (1 H, d, J = 4.7 Hz), 5.24 (1 H, dt, J = 15.8,
6.5 Hz), 4.27 (1 H, d, J = 15.3 Hz), 4.13 (1 H, dd, J = 15.3, 4.7 Hz),
3.68 (6 H, s), 3.63 (3 H, s), 2.60 (2 H, d, J = 7.6 Hz), 2.28 (3 H, s),
1.70 (8 H, m).
13C NMR (75 MHz, CDCl3): = 170.8, 166.2, 142.8, 142.5, 140.1,
139.8, 136.0, 132.9, 129.3, 128.4, 128.0, 127.9, 127.0, 126.4, 123.4,
122.0, 69.5, 57.0, 54.2, 52.6, 51.6, 35.7, 32.0, 27.6, 21.4.
IR (neat): 2022, 1940, 1732 cm–1.
1H NMR (400 MHz, CDCl3): = 7.35–7.07 (9 H, m), 6.58 (1 H, dt,
J = 15.8, 7.7 Hz), 5.82 (1 H, d, J = 15.8 Hz), 5.61 (1 H, d, J = 15.7
Hz), 5.54 (1 H, d, J = 3.4 Hz), 5.50 (5 H, s), 5.02 (1 H, dt, J = 15.7,
7.5 Hz), 4.26 (1 H, d, J = 15.5 Hz), 4.11 (1 H, dd. J = 15.5, 3.4 Hz),
3.88. 3.86, 3.89 (9 H, 3s), 2.65–2.20 (4 H, m), 2.25 (3 H, s).
13C NMR (100 MHz, CDCl3): = 225.6, 215.8, 214.5, 170.4, 166.1,
145.7, 142.7, 142.6, 141.1, 136.0, 131.6, 129.2, 128.3, 127.8, 127.4,
126.7, 124.5, 123.9, 91.3, 70.5, 69.5, 57.2, 52.5, 51.4, 36.9, 34.7,
21.3.
MS (EI, 75 eV): m/z = 581.
HRMS (EI): m/z calcd for C31H35NSO8: 581.2083; found:
581.2086.
Trimethyl (1S*,3aS*,4S*,4aR*,7aS*)-1-Phenyl-3,3a,4,4a,5,6,-
7,7a-octahydro-1H-cyclopenta[f]-isobenzofuran-4,6,6-tracar-
boxylate (23)
Anal. Calcd for C38H37NO11SW: C, 50.74; H, 4.15; N, 1.56. Found:
C, 50.76; H, 4.18; N, 1.60.
A solution of furyl diene 16 (200 mg, 0.48 mmol) in toluene (1.0
mL) was heated at 110 °C for 8 h, then the solution was cooled, con-
centrated and purified by preparative TLC (silca) to give 23 as a col-
orless oil (170 mg, 0.42 mmol).
Tungsten- 1-2,5-dihydropyrrole Complex (20)
Complex 12 (2.0 g), PhCH=NTs and BF3 OEt2, were reacted ac-
cording to the procedure described for 13 to yield 20 as a yellow oil
(2.25 g, 81%).
IR (neat): 1731 cm–1.
IR (neat): 2023, 1936,1732 cm–1.
1H NMR (400 MHz, CDCl3): = 7.27–7.18 (5 H, m), 5.82 (1 H, s),
5.24 (1 H, s), 4.05 (1 H, t, J = 7.7 Hz), 3.67 (3 H, s), 3.65 (3 H, s),
3.64 (3 H, s), 3.49 (1 H, dd, J = 11.6, 7.7 Hz), 3.17 (1H, dd, J = 11,6,
7.7 Hz), 2.73 (1 H, dd, J = 11.6, 9.8 Hz), 2.57 (2 H, m), 2.09 (1 H,
m), 1.82 (1 H, t, J = 10 Hz), 1.77 (2 H, m).
13C NMR (100 MHz, CDCl3): = 173.1, 172.9, 172.6, 144.1, 142.2,
129.4, 127.6, 125.5, 122.4, 81.2, 69.5, 59.2, 52.8, 51.6, 44.4, 43.6,
42.9, 39.2, 38.0, 37.7.
1H NMR (400 MHz, CDCl3): = 7.36–7.07 (9 H, m), 6.68 (1 H, dt,
J = 15.7, 7.8 Hz), 5.79 (1 H, d, J = 15.7 Hz), 5.76 (1 H, d, J = 15.6
Hz), 5.54 (1 H, d, J = 2.9 Hz), 5.46 (5 H, s), 5.19 (1 H, dt, J = 15.6,
7.7 Hz), 4.22 (1 H, d, J = 15.4 Hz), 4.09 (1 H, dd. J = 15.4, 2.9 Hz),
3.88. 3.86, 3.89 (9 H, 3 s), 2.66 (2 H, m), 2.30 (3 H, s), 1.76 (4 H, m).
13C NMR (100 MHz, CDCl3): = 226.0, 215.9, 214.4, 170.8, 166.1,
146.3, 142.7, 142.6, 141.1, 136.2, 131.5, 129.2, 128.4, 128.3, 127.6,
127.3, 126.8, 124.5, 120.9, 91.3, 70.5, 69.3, 57.0, 52.5, 51.5, 35.7,
32.6, 39.3, 21.3.
HRMS (EI): m/z calcd for C23H26O7: 414.1679, found: 414,1676.
MS (EI, 75 eV): m/z = 913 (M+).
Trimethyl (1S*,3aS*,4S*,4aR*,7aS*)-1-Isopropyl -
3,3a,4,4a,5,6,-7,7a-octahydro-1H-cyclopenta[f]-isobenzofuran-
4,6,6-tracarboxylate (24)
Compound 17 (0.2 g), underwent an intramolecular Diels–Alder re-
action according to the procedure described for 23 to give 24 as a
colorless oil (0.17 g, 84%).
Anal. Calcd for C39H39NO11SW: C, 55.14; H, 4.63; N, 1.53. Found:
C, 55.15; H, 4.65; N, 1.50.
Trimethyl (1E,6E)-7-{[1-(4-Methylphenyl)-sulfonyl]-2-phenyl-
2,5-dihydro-1H-3-pyrrolyl}-1,6-heptadiene-1,4,4-tricarboxy-
late (21)
IR (neat): 1734 cm–1.
Compound 19 (1.0 g), Me3NO and CH3CN were reacted according
to the procedure described for 16 to give 21 as a colorless oil (0.35
g, 56%).
IR (neat): 1729 cm–1.
1H NMR (400 MHz, CDCl3): = 7.29–6.91 (9 H, m), 6.51 (1 H, dt,
J = 16.0, 7.0 Hz), 5.86 (1 H, d, 16.0 Hz), 5.70 (1 H, s); 5.58–5.52 (2
H, m), 5.07 (1 H, dt, J = 16.0, 7.8 Hz), 4.31 (1 H, d, J = 15.6 Hz),
1H NMR (400 MHz, CDCl3): = 5.63 (1 H, s), 3.98 (1 H, d, J = 5.1
Hz), 3.61 (1 H, t, J = 7.1 Hz), 3.66 (3 H, s), 3.65 (3 H, s), 3.61 (s, 3
H), 3.26 (1 H, dd, J = 11.7, 7.1 Hz), 3.03 (1 H, dd, J = 11.7, 7.1 Hz),
2.77 (1 H, dd, J = 11.2, 10.6 Hz), 2.62 (2 H, m), 2.13 (1 H, m), 1.86–
1.71 (3 H, m), 1.65 (1 H, m), 0.84 (3 H, d, J = 7.0 Hz), 0.80 (3 H, d,
J = 7.0 Hz).
Synthesis 2002, No. 16, 2457–2463 ISSN 0039-7881 © Thieme Stuttgart · New York

FEATURE ARTICLE
Stereocontrolled Construction of Tricyclic Furan and Pyrrolyl Derivatives
2463
13C NMR (75 MHz, CDCl3): =173.0, 172.9, 172.5, 142.9, 127.2,
85.0, 68.9, 59.1, 52.7, 51.4, 44.5, 43.4, 42.8, 40.1, 38.1, 37.7, 33.1,
18.0, 17.8.
13 C NMR (100 MHz, CDCl3): = 172.6, 172.2,170.9, 143.9, 140.8,
138.6, 133.8, 129.7, 128.4, 127.7, 127.5, 125.9, 125.3, 65.9, 55.0,
52.7, 52.4, 51.7, 50.2, 45.6, 38.2, 35.8, 34.9, 35.0, 31.0, 29.0, 21.5.
HRMS (EI): m/z calcd for C20H28O7: 380.1835; found: 380.1832.
HRMS (EI): m/z calcd for C31H35NO8S: 581.2083; found:
581.2085.
Trimethyl (1S*,3aS*,4S*,4aR*,6aS*)-1-Phenyl-1,3,3a, 4,4a,
5,6,7,8,8a-decahydrobenzo[f]isobenzofuran-4,6,6-tricarboxy-
late (25)
Acknowledgment
Compound 18 (0.2 g), underwent an intramolecular Diels–Alder re-
action according to the procedure described for 23 to give 25 as a
colorless oil (0.16 g, 83%).
The authors like to thank National Science Council for financial
support of this work.
IR (neat): 1731 cm–1.
References
1H NMR (400 MHz, CDCl3): = 7.27–7.15 (5 H, m), 5.44 (1 H, s),
5.23 (1 H, s), 3.95 (1 H, t, J = 7.7 Hz), 3.81 (3 H, s), 3.65 (3 H, s),
3.62 (3 H, s), 3.50 (1 H, dd, J = 11.5, 7.7 Hz), 3.05 (1 H, dd,
J = 11.5, 7.7 Hz), 2.60 (1 H, t, J = 10.4 Hz), 2.39 (2 H, m), 1.86 (1
H, dd. J = 13.4, 3.3 Hz), 1.70–1.62 (2 H, m), 1.47–1.37 (3 H, m).
13C NMR (100 MHz, CDCl3): = 173.1, 172.4, 171.0, 142.5, 142.2,
128.4, 127.6, 125.6, 124.4, 81.4, 69.8, 55.3, 52.7, 52.5, 51.6, 45.9,
38.1, 37.7, 36.5, 35.8, 31.1, 29.2.
(1) Donnelly, D. M. X.; Meegan, M. J. In Comprehensive
Heterocyclic Chemistry, Vol. 4; Katritzky, A. R.; Rees, C.
W., Eds.; Pergamon: New York, 1984, 657–712.
(2) (a) Konitz, A.; Ledochowska, B. M.; Dauter, Z.; Hempel, A.;
Borowski, E. Tetrahedron Lett. 1977, 38, 3401. (b) Trost,
B. M.; Chung, J. Y. L. J. Am. Chem. Soc. 1985, 107, 4586.
(c) Ayer, W. A.; Saeedi-Ghomi, M. H. Tetrahedron Lett.
1981, 22.
(3) (a) Boeckman, R. K. Jr.; Ko, S. J. Am. Chem. Soc. 1980, 102,
7146. (b) Boeckman, R. K. Jr.; Alessi, T. R. J. Am. Chem.
Soc. 1982, 104, 3216. (c) Klemm, L. H.; Klemm, R. A.;
Santhanam, J. P.; White, D. V. J. Org. Chem. 1971, 36,
2169.
(4) Hart, D. J.; Wu, W. L.; Kozikowski, A. P. J. Am. Chem. Soc.
1995, 117, 9369.
(5) Wang, S.-H.; Shiu, L.-H.; Liao, Y.-L.; Wang, S.-L.; Lee, G.-
H.; Peng, S. M.; Liu, R.-S. J. Am. Chem. Soc. 1996, 118,
530.
(6) Shieh, S.-J.; Tang, T.-Z.; Lee, J.-S.; Lee, G.-H.; Peng, S.-M.;
Liu, R.-S. J. Org. Chem. 1996, 61, 3245.
(7) Pei, C.-C.; Liu, R.-S. Org. Lett. 2001, 3, 1295.
(8) (a) Appel, H. H.; Bond, R. P. M.; Overton, K. H.
Tetrahedron 1963, 19, 635. (b) Okuda, R. K.; Scheuer, P. J.
J. Org. Chem. 1983, 48, 1866.
HRMS (EI): m/z calcd for C24H28O7: 428.1835; found: 428.1836.
Trimethyl (1S*,3aS*,4S*,4aR*,7aS*)-2-{4-[(4-Methylphenyl)-
sulfonyl]phenyl}-1-phenyl-2,3,3a,4,4a,5,6,7,7a-decahydro-1H-
cyclopenta[f]-isoindole-4,6,6-tricarboxylate (26)
Compound 21 (0.2 g), underwent an intramolecular Diels–Alder re-
action according to the procedure described for 23 to give 26 as a
colorless oil (0.18 g, 88%).
IR (neat): 1731 cm–1.
1H NMR (400 MHz, CDCl3): = 7.65–7.23 (9 H, m), 5.60 (1 H, s),
4.98 (1 H, s), 3.72 (3 H, s), 3.68 (3 H, s), 3.66 (3 H, s), 3.55 (1 H,
dd, J = 8.5 Hz), 3.12 (1 H, dd, J = 12.1, 8.5 Hz), 2.90 (1 H, dd,
J = 12.1, 8.6 Hz), 2.63 (1 H, dd, J = 12.1, 8.6 Hz), 2.55 (1 H, dd,
J = 12.4, 8.5 Hz), 2.43 (4 H, m), 1.95 (1 H, m), 1.75–1.41 (3 H, m).
13C NMR (100 MHz, CDCl3): = 172.7, 172.5, 172.4, 143.6, 140.8,
140.5, 133.8, 129.7, 128.4, 127.8, 127.5, 125.6, 123.1, 65.8, 58.6,
52.8, 51.6, 50.0, 44.7, 42.4, 41.7, 37.7, 37.2, 29.7, 21.5.
(9) (a) Jansen, B. J. M.; Groot, A. D. Nat. Prod. Rep. 1991, 8,
309. (b) Pascual, T. J.; Urones, J. G.; Marcos, I. S.; Diez, D.;
Monje, V. A. Phytochemistry 1986, 25, 711.
(10) Sonogashira, K.; Tohda, Y.; Hagihara, N. Tetrahedron Lett.
1975, 15, 4467.
HRMS (EI): m/z calcd for C30H33NO8S: 567.1927; found:
567.1924.
(11) (a) Welker, M. E. Chem. Rev. 1992, 93, 97. (b) Rosenblim,
M. J. Organomet. Chem. 1986, 300, 191.
(12) (a) Brown, F. K.; Houk, K. N. Tetrahedron Lett. 1985, 26,
2297. (b) Wu, T. C.; Houk, K. N. Tetrahedron Lett. 1985,
26, 2293. (c) Rousch, W. R.; Essenfeld, A. P.; Warmus, J. S.
Tetrahedron Lett. 1987, 28, 2447.
Trimethyl (1S*,3aS*,4S*,4aR*,8aS*)-2-{4-[(4-Methylphenyl)-
sulfonyl]phenyl}-1-phenyl-2,3,3a,4,4a,5,6,7,8,8a-decahydro-
1H-benzo[f]-isoindole-4,6,6-tricarboxylate (27)
Compound 22 (0.2 g), underwent an intramolecular Diels–Alder re-
action according to the procedure described for 23 to give 27 as a
colorless oil (0.17 g, 87%).
(13) (a) Ichihara, A.; Miki, M.; Tazaki, H.; Sakamura, S.
Tetrahedron Lett. 1987, 43, 1175. (b) Burke, S. D.;
Piscopio, A. D.; Buchana, J. L. Tetrahedron Lett. 1988, 29,
2757. (c) Marshall, J. A.; Audia, J. E.; Crote, J. J. Am. Chem.
Soc. 1988, 110, 1290.
IR (neat): 1731 cm–1.
1H NMR (400 MHz, CDCl3): = 7.64–7.23 (9 H, m), 5.21 (1 H, s),
4.99 (1 H, s), 3.76 (3 H, s), 3.66 (3 H, s), 3.64 (3 H, s), 3.40 (1 H, d,
J = 3.2 Hz), 2.93 (2 H, d, J = 3.2 Hz), 2.44–2.52 (4 H, m), 2.38–2.28
(2 H, m), 1.68 (1 H, m), 1.52–1.58 (2 H, m), 1,33 (1 H, t, J = 12.8
Hz), 1.11–0.92 (2 H, m).
Synthesis 2002, No. 16, 2457–2463 ISSN 0039-7881 © Thieme Stuttgart · New York