Facile acid-catalyzed condensation of 2-hydroxy-2,2′-biindan-1, 1′,3,3′-tetrone with phenols, methoxyaromatic systems and enols

Article abstract of DOI:10.1016/j.tet.2004.09.004

Various phenols, methoxy aromatic compounds, 3- and 4-hydroxycoumarins and enols smoothly condense with 2-hydroxy-2,2′-biindan-1,1′,3,3′- tetrone 1 in an acid medium producing 2-aryl/alkyl-2,2′-biindan-1, 1′,3,3′-tetrones in high yields. The adducts of re

Full text of DOI:10.1016/j.tet.2004.09.004

Tetrahedron 60 (2004) 10197–10205
Facile acid-catalyzed condensation of
2-hydroxy-2,20-biindan-1,10,3,30-tetrone with phenols,
methoxyaromatic systems and enols
b
a
Suven Das,a Animesh Pramanik,a, Roland Frohlich and Amarendra Patra
*
¨
aDepartment of Chemistry, University of Calcutta, 92, A. P. C. Road, Kolkata 700 009, India
¨ ¨ ¨
Organisch-Chemisches Institut, Universitat Munster, Corrensstraße 40, D-48149 Munster, Germany
b
Received 12 July 2004; revised 16 August 2004; accepted 2 September 2004
Abstract—Various phenols, methoxy aromatic compounds, 3- and 4-hydroxycoumarins and enols smoothly condense with 2-hydroxy-2,20-
biindan-1,10,3,30-tetrone 1 in an acid medium producing 2-aryl/alkyl-2,20-biindan-1,10,3,30-tetrones in high yields. The adducts of resorcinol,
1,3,5-trihydroxybenzene and a- and b-naphthols of 1 preferably remain in the intramolecular hemi-ketal form, confirmed by X-ray
diffraction studies. On the other hand para and meta substituted phenols condense with 1 in an acid medium to produce 6 or 7 substituted
20,4-spiro(10,30-indanedion)-indeno[3,2-b]chromenes in good yields.
q 2004 Elsevier Ltd. All rights reserved.
1. Introduction
ninhydrin, the instability of the former in acid medium
prevents the study of its electrophilic chemistry towards
various phenols and enolic substrates.1d,2 On the other hand,
the partially reduced derivative of hydrindantin, viz.,
2-hydroxy-2,20-biindan-1,10,3,30-tetrone 1 (Scheme 1),
which can be easily generated by the acid catalyzed
condensation of ninhydrin with 1,3-indanedione,3 is found
to be quite stable in acid medium and therefore creates an
The mechanistic details of the formation of Ruhemann’s
Purple from the reaction of ninhydrin with amino acids is
not fully understood, but it is accepted that the formation of
2,20-dihydroxy-2,20-biindan-1,10,3,30-tetrone, popularly
known as hydrindantin, is a critical step in the whole
process.1 Although hydrindantin is structurally similar to
Scheme 1.
Keywords: 2-Hydroxy-2,20-biindan-1,10,3,30-tetrone; Phenols; Enols; Electrophilic addition; Chromenes.
* Corresponding author. Tel.: C91 33 2484 1647; fax: C91 33 351 9755; e-mail: animesh_in2001@yahoo.co.in
0040–4020/$ - see front matter q 2004 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tet.2004.09.004

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S. Das et al. / Tetrahedron 60 (2004) 10197–10205
Table 1. Preparation of 2-aryl 2,20-biindan-1,10,3,30-tetrones and chromenes by condensation of phenols with 1 in acid medium
Entry
Substrates
Products
Reaction time (h)
Yields (%)a
Mp (8C)b
Scheme 2
1
2
3
4
5
6
7
8
Phenol
o-Cresol
Guaiacol
o-Chlorophenol
Thymol
2,6-Dihydroxyacetophenone
Catechol
Resorcinol
4a
4b
4c
4d
4e
4f
4g
5a
5b
5c
5d
5e
6.0
5.0
5.0
7.0
5.0
4.0
24.0
24.0
24.0
20.0
3.5
73
69
62
72
68
70
55
65
60
61
70
72
272–273
248–250
243–245
236–237
228–230
320–322
264–265
256–258
268–269
280–281
264–265
255–256
9
Orcinol
10
11
12
1,3,5-Trihydroxybenzene
a-Naphthol
b-Naphthol
3.5
Scheme 3
13
14
15
16
17
18
19
20
21
p-Cresol
m-Cresol
p-Methoxyphenol
p-Chlorophenol
p-Bromophenol
m-Iodophenol
p-Chloro-m-cresol
Ethyl p-hydroxybenzoate
Methyl p-hydroxybenzoate
9a
9b
9c
9d
9e
9f
9g
9h
9i
5.0
6.0
6.0
6.0
8.0
8.0
5.0
82
73
68
72
76
65
70
62
65
285–286
254–255
298–299
276–278
304–306
330–332
321–322
225–226
258–259
30.0
32.0
a
Yields refer to pure isolated products.
Mps are uncorrected.
b
opportunity to study its electrophilic chemistry towards
phenols, enols and aromatic substrates.
followed by elimination of water to produce the C-2
carbocation 2a (Scheme 1) which then undergoes nucleo-
philic attack from various phenols, enols and aromatic
substrates.9 Likewise 1 can potentially generate a C-2
carbocation 2b (Scheme 1) in acid medium. So far no efforts
have been made to examine the electrophilic chemistry of
1 towards various substrates. In this paper we have carried
out an extensive study to explore the electrophilic chemistry
of 1.
Various reports established that the C-2 position of
ninhydrin is reactive to nitrogen-, sulfur-, oxygen-, and
carbon-based nucleophiles.4 Acid catalysed condensation of
ninhydrin with various phenols, enols and aromatic
substrates has been studied extensively.5–10 In all these
cases the protonation of the hydroxy group of ninhydrin is
Scheme 2.

S. Das et al. / Tetrahedron 60 (2004) 10197–10205
10199
2. Results and discussion
In the present study it has been noted that 2-hydroxy-2,20-
biindan-1,10,3,30-tetrone 1 like ninhydrin, condenses with
various phenols (Table 1, entries 1–5), polyhydroxy
benzenes (entries 6–10) as well as a- and b-naphthols
(entries 11 and 12). This is done simply by stirring in a
solution of acetic acid and few drops of conc. H2SO4 at
room temperature for a period0 varying from 2.5 to 24 h to
produce the adducts 2-aryl-2,2 -biindan-1,10,3,30-tetrones 4
in high yield (Scheme 2). In general, 1 is found to be slightly
less reactive than ninhydin in acid medium5 because the
carbocation 2b generated from 1 is comparatively less stable
and more sterically crowded than that of the oxonium ion 2a
derived from ninhydrin (Scheme 1).9a As a result, 1 needs a
few drops of conc. H2SO4 as catalyst in the reaction, and
longer reaction time for adduct formation. The electrophilic
attack to phenols generally takes place at the para position
with respect to the hydroxy groups, producing the adducts
2-aryl-2,20-biindan-1,10,3,30-tetrones 4a–e. 1H and 13C
NMR spectra for most of the adducts 4a–e display a
symmetrical pattern for two 1,3-dioxoindane moieties
indicating tetraketo structures with a plane of symmetry.
Figure 2. X-ray crystal structure of hemi-ketal 5e.
report7a that the acid catalyzed condensation with ninhydrin
generally fails if an electron-withdrawing group like –NO2,
–CHO, –CO2Et etc. is attached to the benzene ring of the
phenolic substrate 3. It is found by NMR study that in spite
of having an ortho hydroxy group with respect to the newly
formed C–C bond in the adduct 4f, hemi-ketal formation
does not occur, probably due to the electron-withdrawing
effect of the acetyl group.
In the case of substrates like resorcinol, orcinol, 1,3,5-tri-
hydroxybenzene as well as a- and b-naphthols the
electrophilic attack of carbocation 2b takes place at the
1
ortho position with respect to the hydroxy groups. H and
13C NMR spectra of these adducts 4h–l show an
unsymmetrical structure formation. This observation indi-
cates that they preferably remain in the intramolecular
hemi-ketal form 5 (Scheme 2). Further X-ray studies of the
adducts 5c and 5e derived by the condensation of 1 with
1,3,5-trihydroxybenzene and b-naphthol, respectively, con-
firm the hemi-ketal structures with the cis geometry of the
vicinal –OH and 1,3-indanedionyl moiety at the bridgehead
of the bicyclo[3.3.0] system (Figs. 1 and 2).11 In the case of
catechol, the newly formed C–C bond does not have any
ortho hydroxy group for the formation of a hemi-ketal, and
as a result it produces a symmetrical adduct 4g. 2,6-
Dihydroxyacetophenone (entry 6) also undergoes the
reaction as with other polyhydroxy benzenes (entries
7–10) to produce adduct 4f, in contrast to the earlier
Interestingly it was observed that para or meta substituted
phenols 6a–i such as p-cresol, m-cresol, p-methoxyphenol,
p-bromophenol, m-iodophenol etc. condense0with 1 in aci0d
medium to furnish 6 or 7 substituted 2 ,4-spiro(10,3 -
indanedion)-indeno[3,2-b]chromenes12 9a–i as yellow pre-
cipitates in fairly good yields (Table 1, Scheme 3). In these
reactions initially the arylated intermediates 2-aryl-2,20-
biindan-1,10,3,30-tetrones 7a–i are formed by the nucleo-
philic attack of phenols 6a–i to the carbocation 2b in the
acetic acid and conc. H2SO4 mixture (Scheme 3).
Subsequently, the arylated intermediates 7a–i undergo an
intramolecular nucleophilic attack by the phenolic hydroxy
0
0
group to either of the carbonyl groups at C1 or C3 , followed
by dehydration to furnish chromenes 9a–i. The para or meta
substituted phenols 6a–i are required for the reaction which
ensure the initial formation of adducts only ortho to the
phenolic hydroxy group. The intermediates 7a–i and 8a–i
were not isolated. Ethyl and methyl p-hydroxy benzoates
6h,i are found to take a longer time for chromene formation
than the phenols 6a–g due to the electron-withdrawing
effect of the ethyl and methyl carboxylate groups (Table 1).
All the chromenes 9a–i were thoroughly characterized by
1H and 13C NMR studies and confirmed for 9a by two
dimensional 13C–1H correlation studies. The solid state
structure of 9b was determined by single crystal X-ray
diffraction study. The result is shown in Figure 3.
It has also been observed that various methoxy aromatic
systems such as anisole, veratrole, 1,3-dimethoxy-, 1,4-di-
methoxy- and 1,2,3-trimethoxybenzene (Table 2, entries
22–26) react with 1 in acetic acid and few drops of conc.
H2SO4 at room temperature to furnish the adduct 2-aryl-
2,20-biindan-1,10,3,30-tetrones 10a–e in high yields
Figure 1. X-ray crystal structure of hemi-ketal 5c.

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S. Das et al. / Tetrahedron 60 (2004) 10197–10205
Scheme 3.
Scheme 4.
(Scheme 4). In the case of anisole, the preferred electro-
philic attack is at the para position with respect to the
1
methoxy group. H and 13C NMR spectra of the adducts
10a–e indicate the formation of symmetrical tetrone
structures. X-ray structure of the adduct 10e derived from
1 and 1,2,3-trimethoxybenzene shows the preferred confor-
mation of the molecule in the solid state (Fig. 4).11
Figure 3. Diamond-plot of chromene 9b with thermal ellipsoids (50%
probability) and atom numbering scheme.
Table 2. Preparation of 2-aryl/alkyl 2,20-biindan-1,10,3,30-tetrones by condensation of methoxy aromatic systems and enols with 1 in acid medium
Entry
Substrates
Products
Reaction time (hr)
Yields (%)a
Mp (8C)b
Scheme 4
22
23
24
25
26
Anisole
10a
10b
10c
10d
10e
3.0
4.0
2.5
4.0
4.5
75
72
75
70
67
239–240
225–226
230–231
217–218
221–222
1,2-Dimethoxybenzene
1,3-Dimethoxybenzene
1,4-Dimethoxybenzene
1,2,3-Trimethoxybenzene
Scheme 5
27
28
29
30
4-Hydroxycoumarin
3-Hydroxycoumarin
1,3-Indanedione
11a
11b
11c
11d
4.0
4.0
5.0
4.5
68
65
62
60
296–298
259–260
Ref.13
1,3-Cyclohexadione
288–290
a
Yields refer to pure isolated products.
Mps are uncorrected.
b

S. Das et al. / Tetrahedron 60 (2004) 10197–10205
10201
4h–l which stay mainly in the hemi-ketal form 5a–e
(Scheme 2). X-ray study of the adduct 11c derived from 1
and 1,3-indanedione shows a structure with a C2 axis of
symmetry (Fig. 5).11
In summary, efficient routes to 2-aryl/alkyl-2,20-biindan-
1,10,3,30-tetrones and some hemi-ketals of the bicyclo-
[3.3.0]octano system have been derived th0roug0h facile
condensation of 2-hydroxy-2,20-biindan-1,1 ,3,3 -tetrone
with hydroxy- and methoxy aromatic systems as well as
with enols under acid catalysis. The study has also led to the
development of a new and facile meth0od for the preparation
of 6 or 7 substituted 20,4-spiro(10, 3 -indanedion)-indeno-
[3,2-b]chromenes from readily available ninhydrin.
3. Experimental
Melting points were determined in open capillary tubes. IR
spectra were examined in KBr disc on a Perkin–Elmer-782
spectrophotometer. Proton magnetic resonance spectra (1H
NMR) and carbon magnetic resonance spectra (13C NMR)
were recorded on Bruker AM 300L (300 MHz) or a Bruker
DRX-500 (500 MHz) spectrometers in the solvents indi-
cated. Chromatography was performed on Merck silica gel
60. TLC analyses were run on Merck silica gel (60F-254)
plates (0.25 mm), precoated with a fluorescent indicator.
Figure 4. X-ray crystal structure of 10e.
4- and 3-Hydroxycoumarins (Table 2, entries 27 and 28)
behave like enolic compounds and react with 1 in AcOH/
H2SO4 to produce adducts 11a and 11b when stirred for
about 4 h at room temperature (Scheme 5). 1,3-Indanedione
and 1,3-cyclohexadione, which preferably remain in enolic
form, also react with 1 to furnish the products 11c and 11d,
respectively. The biologically active trisindanedione 11c
was also synthesized previously from ninhydrin.13 The
adducts 11a–d display somewhat symmetrical H and 13C
NMR spectra for the two 1,3-dioxoindane parts, and thus
prefer to remain in the tetraketo form in contrast to adducts
1
3.1. Preparation of 2-hydroxy-2,20-biindan-1,10,3,30-
tetrone 1
The substrate 1,3-indanedione (0.61 g, 4.2 mmol) was
added to a solution of ninhydrin (0.25 g, 1.4 mmol) in
acetic acid (10 mL). The mixture was stirred at room
temperature for 2 h. The white solid product 1 was filtered
out and washed thoroughly with acetic acid and then with
water. The product 1 was purified by silica-gel column
chromatography using CHCl3 as the eluent (yieldw87%).
3.1.1. 2-Hydroxy-2,20-biindan-1,10,3,30-tetrone 1. White
solid, mp 189–191 8C, IR (KBr): (cmK1) 3428, 1704, 1586,
1264; 1H NMR (300.13 MHz, CDCl3) d: 8.02–7.83 (8H, m),
5.46 (1H, s), 3.97 (1H, s); 13C NMR (75.47 MHz, CDCl3) d:
197.3 (2C), 196.2 (2C), 142.2 (2C), 141.2 (2C), 136.6 (d,
2C), 136.3 (d, 2C), 124.3 (d, 2C), 123.6 (d, 2C), 76.3, 53.4
(d). Anal. Calcd for C18H10O5: C, 70.59; H, 3.29. Found: C,
70.64; H, 3.35%.
Scheme 5.
3.2. General procedure for preparation of 2-aryl/alkyl-
2,20-biindan-1,10,3,30-tetrones (entries 1–30)
A mixture of 2-hydroxy-2,20-biindan-1,10,3,30-tetrone 1
(0.43 g, 1.4 mmol) in acetic acid (8 mL) was warmed to
make a clear solution. The appropriate substrates such as
phenols (3 and 6), methoxybenzenes (Ar-H), enols (R-H)
etc. (4.2 mmol) and 0.5–1.0 mL conc. H2SO4 were then
added (for catechol, resorcinol, orcinol and 1,3,5-trihydroxy-
benzene addition of H2SO4 is not necessary) at room
temperature and stirred for a certain period (Tables 1 and 2).
The solid products were filtered out and washed thoroughly
with acetic acid and then with water. The products were
purified by silica-gel column chromatography using ethyl
Figure 5. X-ray crystal structure of trisindanedione 11c.

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S. Das et al. / Tetrahedron 60 (2004) 10197–10205
acetate and pet-ether as eluent. The resulting solids were
further purified by crystallization from CHCl3/pet-ether.
131.9, 125.5, 124.3, 123.5, 111.2, 65.0, 55.3, 32.3. Anal.
Calcd for C26H16O7: C, 70.91; H, 3.66. Found: C, 70.85; H,
3.73%.
3.2.1. 2-(4-Hydroxyphenyl)-2,20-biindan-1,10,3,30-tet-
rone, 4a. White solid, mp 272–273 8C, IR (KBr): (cmK1
)
3.2.7. 2-(3,4-Dihydroxyphenyl)-2,20-biindan-1,10,3,30-
tetrone, 4g. Light greenish solid, mp 264–265 8C, IR
(KBr): (cmK1) 3429, 1702, 1589, 1264, 1194, 769; 1H NMR
(500 MHz, acetone-d6) d: 7.99–7.86 (8H, m), 6.92 (1H, d,
JZ2.1 Hz), 6.76 (1H, d, JZ8.3 Hz), 6.67 (1H, dd, JZ8.3,
2.1 Hz), 4.49 (1H, s). Anal. Calcd for C24H14O6: C, 72.36;
H, 3.54. Found: C, 72.43; H, 3.61%.
3482, 1702, 1588, 1263, 771; 1H NMR (300.13 MHz,
acetone-d6) d: 8.68 (1H, br. s), 7.99–7.85 (8H, m), 7.21 (2H,
d, JZ8.8 Hz), 6.82 (2H, d, JZ8.8 Hz), 4.56 (1H, s); 13C
NMR (75.47 MHz, acetone-d6) d: 199.0 (2C), 197.6 (2C),
158.3, 143.2 (2C), 142.5 (2C), 137.1 (d, 2C), 136.6 (d, 2C),
129.8 (d, 2C), 125.1, 124.5 (d, 2C), 123.6 (d, 2C), 116.5 (d,
2C), 65.1, 56.4 (d). Anal. Calcd for C24H14O5: C, 75.39; H,
3.69. Found: C, 75.45; H, 3.74%.
3.2.8. 2-(2,4-Dihydroxyphenyl)-2,20-biindan-1,10,3,30-
tetrone, 4h (remains as hemiketal 5a). White solid, mp
256–258 8C, IR (KBr): (cmK1) 3293, 1709, 1603, 1267,
1136, 767; 1H NMR (500 MHz, acetone-d6) d:8.40 (1H, s),
7.87–7.76 (7H, m), 7.64–7.61 (1H, m), 7.41 (1H, s), 7.27
(1H, d, JZ8.3 Hz), 6.50 (1H, dd, JZ8.3, 2.1 Hz), 6.21 (1H,
d, JZ2.1 Hz), 4.40 (1H, s); 13C NMR (125 MHz, acetone-
d6) d: 198.3, 197.6, 196.5, 160.1, 158.4, 150.7, 143.1, 141.8,
136.0, 135.9, 135.4, 135.2, 130.9, 125.4, 124.2, 123.7,
122.8, 122.7, 116.0, 113.3, 109.3, 97.6, 65.4, 55.0.
Anal.Calcd for C24H14O6: C, 72.36; H, 3.54. Found: C,
72. 45; H, 3.64%.
3.2.2.
2-(3-Methyl-4-hydroxyphenyl)-2,20-biindan-
1,10,3,30-tetrone, 4b. White solid, mp 248–250 8C, IR
(KBr): (cmK1) 3292, 1705, 1592, 1264, 757; 1H NMR
(300.13 MHz, acetone-d6) d: 8.55 (1H, s), 7.98–7.83 (8H,
m), 7.13 (1H, d, JZ2.2 Hz), 6.98 (1H, dd, JZ8.6, 2.2 Hz),
6.77 (1H, d, JZ8.6 Hz), 4.55 (1H, s), 2.08 (3H, s); 13C
NMR (75.47 MHz, acetone-d6) d: 199.0 (2C), 197.6 (2C),
156.4, 143.2 (2C), 142.5 (2C), 137.1 (d, 2C), 136.6 (d, 2C),
131.0 (d), 127.2 (d), 125.6, 125.1, 124.5 (d, 2C), 123.6 (d,
2C), 115.9 (d), 64.2, 56.5 (d), 16.4 (q). Anal. Calcd for
C25H16O5: C, 75.75; H, 4.07. Found: C, 75.81; H, 4.14%.
3.2.9. 2-(2,4-Dihydroxy-6-methylphenyl)-2,20-biindan-
1,10,3,30-tetrone, 4i (remains as hemiketal 5b). White
solid, mp 268–269 8C, IR (KBr): (cmK1) 3429, 1704, 1587,
3.2.3. 2-(3-Methoxy-4-hydroxyphenyl)-2,20-biindan-
1,10,3,30-tetrone, 4c. White solid, mp 243–245 8C, IR
(KBr): (cmK1) 3528, 1709, 1515, 1263; 1H NMR
(300.13 MHz, CDCl3) d: 7.99–7.96 (2H, m), 7.90–7.87
(2H, m), 7.85–7.79 (4H, m), 7.03 (1H, d, JZ1.7 Hz), 6.88–
6.81 (2H, m), 5.66 (1H, s), 4.21 (1H, s), 3.89 (3H, s). Anal.
Calcd for C25H16O6: C, 72.81; H, 3.91. Found: C, 72.90; H,
3.85%.
1
1265, 1214; H NMR (500 MHz, acetone-d6) d: 8.27 (1H,
s), 7.85–7.74 (7H, m), 7.64–7.62 (1H, m), 7.33 (1H, s), 6.30
(1H, d, JZ1.5 Hz), 6.03 (1H, d, JZ1.9 Hz), 4.67 (1H, s),
2.58 (3H, s). Anal. Calcd for C25H16O6: C, 72.81; H, 3.91.
Found: C, 72.93; H, 4.01%.
3.2.10. 2-(2,4,6-Trihydroxyphenyl)-2,20-biindan-1,10,
3,30-tetrone, 4j (remains as hemiketal 5c). White solid,
mp 280–281 8C, IR (KBr): (cmK1) 3445, 3325, 1710, 1620,
3.2.4.
2-(3-Chloro-4-hydroxyphenyl)-2,20-biindan-
1,10,3,30-tetrone, 4d. White solid, mp 236–237 8C, IR
(KBr): (cmK1) 3221, 1704, 1589, 1266, 761; 1H NMR
(300.13 MHz, CDCl3) d: 8.00–7.96 (2H, m), 7.90–7.79 (6H,
m), 7.42 (1H, d, JZ2.3 Hz), 7.27 (1H, dd, JZ8.7, 2.3 Hz),
6.99 (1H, d, JZ8.7 Hz), 5.69 (1H, s), 4.18 (1H, s). Anal.
Calcd for C24H13O5Cl: C, 69.15; H, 3.14; Cl, 8.52. Found:
C, 69.23; H, 3.21; Cl, 8.61%.
1
1465, 1269, 1132; H NMR (300.13 MHz, acetone-d6) d:
8.39 (1H, s), 8.05 (1H, s), 7.89–7.80 (8H, m), 7.47 (1H, s),
6.01 (1H, d, JZ1.8 Hz), 5.78 (1H, d, JZ1.8 Hz), 4.67 (1H,
s). Anal. Calcd for C24H14O7: C, 69.56; H, 3.41. Found: C,
69.62; H, 3.50%.
3.2.11. 2-(1-Hydroxynaphthyl)-2,20-biindan-1,10,3,30-
tetrone, 4k (remains as hemiketal 5d). Light yellow
solid, mp 264–265 8C, IR (KBr): (cmK1) 3401, 1704, 1590,
1256, 774; 1H NMR (300.13 MHz, DMSO-d6) d: 8.85 (1H,
d, JZ6.3 Hz), 8.51 (1H, d, JZ8.1 Hz), 8.22 (1H, d, JZ
8.1 Hz), 8.15–7.79 (4H, m), 7.56–7.30 (4H, m), 6.94 (1H,
dd, JZ7.9, 1.5 Hz), 6.84 (1H, d, JZ7.8 Hz), 6.73–6.69 (1H,
m), 5.55 (1H, s); 13C NMR (75.47 MHz, DMSO-d6) d:
198.3, 198.0, 197.3, 154.5, 154.0, 141.5, 141.2, 137.6,
137.1, 136.6, 133.8, 129.7, 127.2, 126.6, 126.3, 125.3,
124.7, 124.4, 123.6, 123.5, 121.0, 120.4, 108.2, 108.1,
107.9, 66.8, 63.7, 55.5. Anal. Calcd for C28H16O5: C, 77.77;
H, 3.73. Found: C, 77.83; H, 3.65%.
3.2.5. 2-(2-Methyl-4-hydroxy-5-isopropylphenyl)-2,20-
biindan-1,10,3,30-tetrone, 4e. Light yellow solid, mp 228–
230 8C, IR (KBr): (cmK1) 3310, 1703, 1590, 1259, 758; 1H
NMR (300.13 MHz, CDCl3) d: 7.99–7.96 (2H, m), 7.91–
7.86 (2H, m), 7.85–7.78 (5H, m), 6.84 (1H, s), 6.53 (1H, s),
4.65 (1H, s), 3.02–2.98 (1H, m), 2.53 (3H, s), 1.05 (6H, d,
JZ11.1 Hz); 13C NMR (75.47 MHz, CDCl3) d: 198.5 (2C),
197.0 (2C), 152.3, 142.3 (4C), 137.2, 135.6 (d, 2C), 135.4
(d, 2C), 132.0, 128.1, 123.8 (d, 2C), 123.2 (d, 2C), 120.0,
66.0, 54.6 (d), 27.2 (d), 22.3 (q, 2C), 22.1 (q). Anal. Calcd
for C28H22O5: C, 76.70; H, 5.06. Found: C, 76.78; H, 5.13%.
3.2.6. 2-(2,4-Dihydroxy-3-acetylphenyl)-2,20-biindan-
1,10,3,30-tetrone, 4f. White solid, mp 320–322 8C, IR
3.2.12. 2-(2-Hydroxynaphthyl)-2,20-biindan-1,10,3,30-
tetrone, 4l (remains as hemiketal 5e). White solid, mp
255–256 8C, IR (KBr): (cmK1) 3263, 1704, 1593, 1270,
722; 1H NMR (300.13 MHz, DMSO-d6) d: 8.82 (1H, br. s),
8.47 (1H, d, JZ8.5 Hz), 7.89–7.70 (6H, m), 7.61–7.50 (4H,
m), 7.34 (1H, t, JZ7.8 Hz), 7.05 (1H, d, JZ8.8 Hz), 5.10
1
(KBr): (cmK1) 3283, 1713, 1638, 1274, 1219; H NMR
(300.13 MHz, acetone-d6) d: 7.99–7.66 (8H, m), 7.58 (1H,
d, JZ8.4 Hz), 6.57 (1H, d, JZ8.4 Hz), 4.52 (1H, s), 2.59
(3H, s);13C NMR (125 MHz, acetone-d6): 204.5, 198.0,
197.1, 165.0, 143.6, 142.1, 137.0, 136.4, 136.2, 132.9,

S. Das et al. / Tetrahedron 60 (2004) 10197–10205
10203
(1H, s). Anal. Calcd for C28H16O5: C, 77.77; H, 3.73.
Found: C, 77.85; H, 3.64%.
131.8, 131.4, 129.0, 128.1, 124.7, 122.4, 120.0, 119.4,
105.8, 94.2.
3.2.19. 6-Chloro-7-methyl-20,4-spiro(10, 30-indanedion)-
indeno[3,2-b]chromene, 9g. Yellow solid, mp 321–322 8C,
IR (KBr): (cmK1) 3438, 1707, 1647, 1377, 1245; 1H NMR
(300 MHz, CDCl3) d: 8.10–8.07 (2H, m), 7.96–7.92 (2H,
m), 7.39–7.21 (4H, m), 7.19 (1H, s), 6.52 (1H, s), 2.30 (3H,
s); 13C NMR (125 MHz, CDCl3) d: 198.1, 190.7, 171.0,
149.5, 143.1, 138.8, 137.0, 136.7, 133.2, 132.0, 131.4,
127.6, 124.7, 124.6, 122.3, 121.2, 119.4, 119.0, 105.7, 20.3.
Anal. Calcd for C25H13O4Cl: C, 72.73; H, 3.17; Cl, 8.60.
Found: C, 72.82; H, 3.26; Cl, 8.55%.
3.2.13. 6-Methyl-20,4-spiro(10, 30-indanedion)-indeno-
[3,2-b]chromene, 9a. Yellow solid, mp 285–286 8C, IR
(KBr): (cmK1) 1711, 1649, 1396, 1252; 1H NMR
(300.13 MHz, CDCl3) d: 8.16–8.13 (2H, m), 8.00–7.96
(2H, m), 7.41–7.25 (5H, m), 7.12 (1H, dd, JZ8.4, 1.6 Hz),
6.40 (1H, d, JZ1.6 Hz), 2.14 (3H, s); 13C NMR
(75.47 MHz, CDCl3) d: 198.3 (2C), 190.5, 171.3, 149.1,
143.2 (2C), 136.8, 136.1 (d, 2C), 132.5 (d), 132.0, 130.7 (d),
130.5 (d), 127.6 (d), 124.2 (d, 2C), 123.3, 121.9 (d), 119.7,
118.9 (d), 118.6 (d), 105.7, 54.4, 20.6. Anal. Calcd for
C25H14O4: C, 79.36; H, 3.73. Found: C, 79.30; H, 3.69%.
3.2.20. 6-Carbethoxy-20,4-spiro(10, 30-indanedion)-
indeno[3,2-b]chromene, 9h. Yellow solid, mp 225–
226 8C, IR (KBr): (cmK1) 3437, 1712, 1652, 1392, 1258;
1H NMR (500 MHz, CDCl3) d: 8.17–8.15 (2H, m), 8.03
(1H, d, JZ1.8 Hz), 8.01–7.99 (2H, m), 7.93 (1H, dd, JZ
8.6, 1.8 Hz), 7.44–7.34 (4H, m), 6.81 (1H, d, JZ8.6 Hz),
4.26 (2H, q, JZ7.1 Hz), 1.28 (3H, t, JZ7.1 Hz); 13C NMR
(125 MHz, CDCl3) d: 198.2, 190.8, 171.3, 165.2, 154.4,
143.4, 136.9, 136.7, 133.2, 132.0, 131.6, 131.5, 130.0,
128.9, 124.9, 122.6, 120.6, 119.5, 119.3, 106.3, 61.7, 54.7,
14.6. Anal. Calcd for C27H16O6: C, 74.31; H, 3.70. Found:
C, 74.40; H, 3.81%.
3.2.14. 7-Methyl-20,4-spiro(10, 30-indanedion)-indeno-
[3,2-b]chromene, 9b. Yellow solid, mp 254–255 8C, IR
1
(KBr): (cmK1) 3438, 1709, 1650, 1389, 1243; H NMR
(300.13 MHz, acetone-d6) d: 8.16–8.15 (4H, m), 7.61–7.33
(5H, m), 6.99 (1H, d, JZ7.9 Hz), 6.66 (1H, d, JZ7.9 Hz).
2.36 (3H, s); 13C NMR (125 MHz, CDCl3) d: 198.8, 191.1,
171.8, 151.1, 143.5, 140.8, 137.2, 136.6, 133.0, 132.3,
131.2, 127.6, 127.4, 124.7, 122.3, 119.7, 119.3, 117.4,
106.1, 21.5. Anal. Calcd for C25H14O4: C, 79.36; H 3.73.
Found: C, 79.42; H, 3.81%.
3.2.15. 6-Methoxy-20,4-spiro(10, 30-indanedion)-indeno-
[3,2-b]chromene, 9c. Yellow solid, mp 298–299 8C, IR
3.2.21. 6-Carbomethoxy-20,4-spiro(10, 30-indanedion)-
indeno[3,2-b]chromene, 9i. Yellow solid, mp 258–
259 8C, IR (KBr): (cmK1) 3410, 1711, 1390, 1255; 1H
NMR (300.13 MHz, CDCl3) d: 8.18–8.15 (2H, m), 8.04
(1H, d, JZ1.8 Hz), 8.03–7.99 (2H, m), 7.47–7.34 (6H, m),
3.80 (3H, s); 13C NMR (125 MHz, CDCl3) d: 198.2, 190.7,
171.2, 165.7, 154.5, 143.4, 136.9, 136.7, 133.3, 131.9,
131.7, 131.5, 130.0, 128.5, 124.9, 122.6, 120.6, 119.5,
119.4, 106.3, 54.7, 52.7. Anal. Calcd for C26H14O6: C,
73.93; H, 3.34. Found: C, 74.01; H, 3.41%.
1
(KBr): (cmK1) 3438, 1707, 1645, 1394, 1197; H NMR
(300.13 MHz, CDCl3) d: 8.16–8.13 (2H, m), 7.99–7.97 (2H,
m), 7.40–7.26 (5H, m), 6.87 (1H, dd, JZ9.0, 2.9 Hz), 6.12
(1H, d, JZ2.9 Hz), 3.63 (3H, s); 13C NMR (125 MHz,
CDCl3) d: 198.6, 191.0, 171.9, 157.7, 145.5, 143.4, 137.1,
136.7, 133.0, 132.4, 131.2, 124.7, 122.3, 121.1, 120.1,
119.3, 114.9, 113.2, 106.0, 56.0. Anal. Calcd for C25H14O5:
C, 76.14; H, 3.58. Found: C, 76.25; H, 3.68%.
3.2.16. 6-Chloro-20,4-spiro(10, 30-indanedion)-indeno-
[3,2-b]chromene, 9d. Yellow solid, mp 276–278 8C, IR
(KBr): (cmK1) 1710, 1651, 1394, 1247; 1H NMR
(300.13 MHz, CDCl3) d: 8.10–8.07 (2H, m), 7.95–7.91
(2H, m), 7.38–7.24 (6H, m), 6.53 (1H, d, JZ1.4 Hz). Anal.
Calcd for C24H11O4Cl: C, 72.27; H, 2.78; Cl, 8.90. Found:
C, 72.35, H, 2.86; Cl, 8.79%.
3.2.22. 2-(4-Methoxyphenyl)-2,20-biindan-1,10,3,30-
tetrone, 10a. Light yellow solid, mp 239–240 8C, IR
(KBr): (cmK1) 1705, 1594, 1511, 1264, 762; 1H NMR
(300.13 MHz, CDCl3) d: 7.95–7.80 (8H, m), 7.35 (2H, d,
JZ8.2 Hz), 6.88 (2H, d, JZ8.2 Hz), 4.23 (1H, s), 3.77 (3H,
s); 13C NMR (75.47 MHz, CDCl3) d: 197.9 (2C), 196.5
(2C), 159.8, 142.2 (2C), 141.6 (2C), 135.8 (d, 2C), 135.5 (d,
2C), 128.9 (d, 2C), 124.7, 123.9 (d, 2C), 123.2 (d, 2C), 114.4
(d, 2C), 63.1, 55.9 (q), 55.2 (d). Anal. Calcd for C25H16O5:
C, 75.75; H, 4.07. Found: C, 75.82; H, 4.13%.
3.2.17. 6-Bromo-20,4-spiro(10, 30-indanedion)-indeno-
[3,2-b]chromene, 9e. Yellow solid, mp 304–306 8C, IR
1
(KBr): (cmK1) 3430, 1708, 1654, 1392, 1256; H NMR
3.2.23. 2-(3,4-Dimethoxyphenyl)-2,20-biindan-1,10,3,30-
tetrone, 10b. Light yellow solid, mp 225–226 8C, IR
(KBr): (cmK1) 1703, 1591, 1513, 1255, 764; 1H NMR
(300.13 MHz, CDCl3) d: 7.98–7.78 (8H, m), 7.05 (1H, d,
JZ2.1 Hz), 6.89 (1H, dd, JZ8.5, 2.1 Hz), 6.80 (1H, d, JZ
8.5 Hz), 4.23 (1H, s), 3.87 (3H, s), 3.76 (3H, s); 13C NMR
(75.47 MHz, CDCl3) d: 197.8 (2C), 196.4 (2C), 149.6,
147.2, 142.2 (2C), 141.6 (2C), 135.8 (d, 2C), 135.5 (d, 2C),
125.0, 123.9 (d, 2C), 123.2 (d, 2C), 120.7 (d), 111.6 (d),
111.0 (d), 63.2, 56.2 (q), 56.0 (q), 55.9 (d). Anal. Calcd for
C26H18O6: C, 73.23; H, 4.25. Found: C, 73.31; H, 4.33%.
(300.13 MHz, CDCl3) d: 8.18–8.15 (2H, m), 8.03–7.99 (2H,
m), 7.45–7.36 (5H, m), 7.27 (1H, apparent d, JZ8.1 Hz),
6.74 (1H, d, JZ2.2 Hz); 13C NMR (125 MHz, CDCl3) d:
198.0, 190.7, 171.3, 150.6, 143.3, 137.0, 136.8, 133.3,
133.2, 132.1, 131.4, 130.6, 125.0, 122.6, 122.3, 120.9,
119.4, 119.3, 105.9, 54.6.
3.2.18. 7-Iodo-20,4-spiro(10, 30-indanedion)-indeno[3,2-b]-
chromene, 9f. Yellow solid, mp 330–332 8C, IR (KBr):
(cmK1) 3436, 1710, 1651, 1383, 1251; 1H NMR
(300.13 MHz, CDCl3) d: 8.16–8.13 (2H, m), 8.02–7.98
(2H, m), 7.77 (1H, d, JZ1.7 Hz), 7.47–7.33 (5H, m), 6.37
(1H, d, JZ8.2 Hz); 13C NMR (125 MHz, CDCl3) d: 197.9,
190.6, 171.2, 151.3, 143.1, 137.0, 136.5, 135.6, 133.3,
3.2.24. 2-(2,4-Dimethoxyphenyl)-2,20-biindan-1,10,3,30-
tetrone, 10c. Light yellow solid, mp 230–231 8C, IR

10204
S. Das et al. / Tetrahedron 60 (2004) 10197–10205
(KBr): (cmK1) 1710, 1592, 1264, 791; 1H NMR
(300.13 MHz, CDCl3) d: 7.94–7.75 (8H, m), 7.29 (1H, d,
JZ8.7 Hz), 6.54 (1H, dd, JZ8.7, 2.2 Hz), 6.39 (1H, d, JZ
2.2 Hz), 4.67 (1H, s), 3.76 (3H, s), 3.52 (3H, s); 13C NMR
(75.47 MHz, CDCl3) d: 197.5 (2C), 196.8 (2C), 160.9,
158.4, 142.2 (4C), 135.3 (d, 2C), 135.1 (d, 2C), 130.4 (d),
123.3 (d, 2C), 123.0 (d, 2C), 115.7, 106.2 (d), 100.5 (d),
62.1, 55.8 (q), 55.3 (q), 54.6 (d). Anal. Calcd for C26H18O6:
C, 73.23; H, 4.25. Found: C, 73.29; H, 4.31%.
2.47–2.33 (6H, m). Anal. Calcd for C24H16O6: C, 71.99; H,
4.03. Found: C, 72.12; H, 4.12%.
3.3. X-ray structure analyses.11
3.3.1. Compound 5c. Formula C24H14O73$H2O, MZ432.37,
˚
colourless crystal 0.35!0.30!0.30 mm , aZ15.516(1) A,
˚
˚
bZ8.764(1) A, cZ15.268(1) A, bZ104.49(1)8, VZ
2010.1(3) A , rcalcZ1.429 g cmK3, mZ1.09 cmK1, empiri-
3
˚
cal absorption correction (0.963%T%0.968), ZZ4, mono-
˚
3.2.25. 2-(2,5-Dimethoxyphenyl)-2,20-biindan-1,10,3,30-
tetrone, 10d. White solid, mp 217–218 8C, IR (KBr):
(cmK1) 1707, 1594, 1502, 1266, 1228, 759; 1H NMR
(300.13 MHz, CDCl3) d: 7.96–7.77 (8H, m), 7.02 (1H, d,
JZ2.1 Hz), 6.85–6.78 (2H, m), 4.64 (1H, s), 3.77 (3H, s),
3.48 (3H, s); 13C NMR (75.47 MHz, CDCl3) d: 197.1 (2C),
196.5 (2C), 154.6, 151.7, 142.4 (2C), 142.3 (2C), 135.4 (d,
2C), 135.1 (d, 2C), 125.0, 123.4 (d, 2C), 123.2 (d, 2C), 116.0
(d), 115.2 (d), 114.6 (d), 61.2, 57.0 (q), 55.8 (q), 55.2 (d).
Anal. Calcd for C26H18O6: C, 73.23; H, 4.25. Found: C,
73.34; H, 4.36%.
clinic, space group P21/c (No. 14), lZ0.71073 A, TZ
198 K, u and f scans, 11435 reflections collected (Gh, G
k, Gl), [(sin q)/l]Z0.66 AK1, 4745 independent (RintZ
˚
0.036) and 3691 observed reflections [IR2s(I)], 298 refined
parameters, RZ0.043, wR2Z0.102, max. residual electron
density 0.33 (K0.28) e AK3, hydrogens at water molecule
˚
from difference fourier calculations, other calculated and all
refined as riding atoms.
3.3.2. Compound 5e. Formula C28H16O5$C3H6O, MZ
490.49, colourless crystal 0.15!0.10!0.05 mm3, aZ
˚
˚
˚
8.525(1) A, bZ17.239(1) A, cZ16.290(1) A, bZ
93.92(1)8, VZ2388.4(3) A , rcalcZ1.364 g cmK3, mZ
3
˚
3.2.26. 2-(2,3,4-Trimethoxyphenyl)-2,20-biindan-1,10,
0.95 cmK1, empirical absorption correction (0.986%T%
3,30-tetrone, 10e. White solid, mp 221–222 8C, IR (KBr):
1
(cmK1) 1708, 1594, 1267, 784; H NMR (300.13 MHz,
0.995), ZZ4, monoclinic, space group P21/n (No. 14), lZ
˚
0.71073 A, TZ198 K, u and f scans, 15689 reflections
CDCl3) d: 7.94–7.76 (8H, m), 7.25 (1H, d, JZ9.0 Hz), 6.75
(1H, d, JZ9.0 Hz), 4.48 (1H, s),3.84 (3H, s), 3.73 (3H, s),
3.51 (3H, s); 13C NMR (75.47 MHz, CDCl3) d: 197.1 (2C),
196.6 (2C), 153.9 (2C), 151.6, 142.3 (2C), 142.2 (2C), 135.4
(d, 2C), 135.1 (d, 2C), 123.8 (d), 123.4 (d, 2C), 123.1 (d,
2C),120.9, 108.1 (d), 61.8, 60.4 (q), 60.1 (q), 56.0 (q), 55.5
(d). Anal. Calcd for C27H20O7: C, 71.05; H, 4.42. Found: C,
71.13; H, 4.51%.
collected (Gh, Gk, Gl), [(sin q)/l]Z0.66 AK1, 5689
˚
independent (RintZ0.059) and 3234 observed reflections
[IR2s(I)], 337 refined parameters, RZ0.057, wR2Z0.112,
max. residual electron density 0.21 (K0.24) e AK3, hydro-
˚
gens calculated and refined as riding atoms.
3.3.3. Compound 9b. Formula C25H14O4, MZ378.36,
3
˚
yellow crystal 0.20!0.10!0.06 mm , aZ7.267(1) A, bZ
˚
˚
9.641(1) A, cZ14.351(1) A, aZ103.85(1)8, bZ101.49(1)8,
3.2.27. 2-[3-(4-Hydroxy coumarin)]-2,20-biindan-1,10,
3,30-tetrone, 11a. White solid, mp 296–298 8C, IR (KBr):
(cmK1) 3190, 1739, 1696, 1273, 757; 1H NMR
(300.13 MHz, DMSO-d6) d: 7.91–7.80 (8H, m), 7.61 (1H,
t, JZ8.5 Hz), 7.52 (1H, d, JZ7.7 Hz), 7.41 (1H, d, JZ
8.4 Hz), 7.27 (1H, t, JZ7.5 Hz), 5.32 (1H, s); 13C NMR
(75.47 MHz, DMSO-d6) d: 197.4 (2C), 197.1 (2C), 162.4,
157.8, 154.6, 141.6 (4C), 135.5 (d, 4C), 133.5 (d), 124.5 (d),
124.2 (d), 122.8 (d, 2C), 122.5 (d, 2C), 116.8 (d), 111.6,
100.0, 64.2, 51.0 (d). Anal. Calcd for C27H14O7: C, 72.00;
H, 3.13. Found: C, 72.08; H, 3.21%.
3
gZ103.89(1)8, VZ911.86(2) A , rcalcZ1.378 g cmK3, mZ
˚
0.93 cmK1, empirical absorption correction (0.982%T%
0.994), ZZ2, triclinic, space group P1bar (No. 2), lZ
˚
0.71073 A, TZ198 K, u and f scans, 7847 reflections
collected (Gh, Gk, Gl), [(sin q)/l]Z0.62 AK1, 3692
˚
independent (RintZ0.050) and 2306 observed reflections
[IR2s(I)], 263 refined parameters, RZ0.052, wR2Z0.108,
max. residual electron density 0.23 (K0.22) e AK3, hydro-
˚
gens calculated and refined as riding atoms.
3.3.4. Compound 10e. Formula C27H20O7, MZ456.43,
3
˚
colourless crystal 0.30!0.30!0.15 mm , aZ7.689(1) A,
3.2.28. 2-[4-(3-Hydroxy coumarin)]-2,20-biindan-1,10,
˚
˚
bZ22.698(1) A, cZ12.166(1) A, bZ95.31(1)8, VZ
3,30-tetrone, 11b. White solid, mp 259–260 8C, IR (KBr):
˚
2114.2(3) A , rcalcZ1.434 g cmK3, mZ1.04 cmK1, no
3
1
(cmK1) 3289, 1713, 1274, 758; H NMR (300.13 MHz,
absorption correction (0.969%T%0.985), ZZ4, mono-
˚
DMSO-d6) d: 9.43 (1H, s), 8.18 (1H, d, JZ7.6 Hz), 7.90–
7.76 (8H, m), 7.69–7.67 (1H, m), 7.49–7.36 (2H, m), 5.16
(1H, s); 13C NMR (75.47 MHz, DMSO-d6) d: 196.6 (2C),
196.5 (2C), 153.1, 150.9, 148.9, 141.7 (2C), 141.0 (2C),
135.6 (d, 2C), 135.5 (d, 2C), 131.3 (d), 128.9 (d), 123.7 (d),
122.7 (d, 2C), 122.6 (d, 2C), 117.5, 116.5 (d), 113.1, 67.1,
53.0 (d). Anal. Calcd for C27H14O7: C, 72.00; H, 3.13.
Found: C, 72.10; H, 3.19%.
clinic, space group P21/c (No. 14), lZ0.71073 A, TZ
198 K, u and f scans, 8798 reflections collected (Gh, Gk,
Gl), [(sin q)/l]Z0.66 AK1, 5003 independent (RintZ
˚
0.026) and 3888 observed reflections [IR2s(I)], 310 refined
parameters, RZ0.043, wR2Z0.108, max. residual electron
density 0.29 (K0.24) e AK3, hydrogens calculated and
˚
refined as riding atoms.
3.3.5. Compound 11c. Formula C27H14O6, MZ434.38,
3
3.2.29. 2-(2,6-Dioxocyclohexanyl)-2,20-biindan-1,10,3,30-
tetrone, 11d. White solid, mp 288–290 8C, IR (KBr):
orange crystal 0.25!0.20!0.20 mm , aZ12.511(1) A,
˚
˚
˚
bZ10.591(1) A, cZ15.533(1) A, bZ95.39(1)8, VZ
(cmK1) 3430, 1709, 1588, 1266; H NMR (300.13 MHz,
DMSO-d6) d: 9.00 (1H, s), 7.90–7.60 (8H, m), 4.65 (1H, s),
2049.1(3) A , rcalcZ1.408 g cmK3, mZ1.0 cmK1, empiri-
1
3
˚
cal absorption correction (0.975%T%0.980), ZZ4,

S. Das et al. / Tetrahedron 60 (2004) 10197–10205
10205
˚
Lacroix, R.; Uchida-Ernouf, G.; Narcisse, G.; Hubert, F. Eur.
J. Med. Chem. 1979, 14, 171.
monoclinic, space group C2/c (No. 15), lZ0.71073 A, TZ
198 K, u and f scans, 6663 reflections collected (Gh, Gk,
Gl), [(sin q)/l]Z0.66 AK1, 2435 independent (RintZ
˚
7. (a) Schmitt, G.; Dinh, A. N.; Poupelin, J.-P.; Vebrel, J.;
Laude, B. Synthesis 1984, 758. (b) Yamazaki, T.; Takizawa, T.
Tetrahedron 1972, 28, 4675.
0.031) and 2085 observed reflections [IR2s(I)], 150 refined
parameters, RZ0.039, wR2Z0.094, max. residual electron
density 0.23 (K0.16) e AK3, hydrogens calculated and
8. Song, H. N.; Seong, M. R.; Son, J. S.; Kim, J. N. Synth.
Commun. 1998, 28, 1865.
˚
refined as riding atoms.
9. (a) Klumpp, D. A.; Fredrick, S.; Lau, S.; Jin, K. K.; Bau, R.;
Surya Prakash, G. K.; Olah, G. A. J. Org. Chem. 1999, 64,
5152. (b) Campbell, L. A.; Morrison, B. J.; Musgrave, O. C.
J. Chem. Res. (S) 2002, 638.
Acknowledgements
The authors are grateful to UGC, New Delhi and the
University of Calcutta for providing financial support. SD is
thankful to CSIR, New Delhi for offering him a Junior
Research Fellowship.
10. Olah, G. A. In Friedel–Crafts and Related Reactions, Wiley:
New York, 1964; Vol. 2, pp 597–640.
11. Data set were collected with a Nonius KappaCCD diffracto-
meter, equipped with a rotating anode generator Nonius
FR591. Programs used: data collection COLLECT (Nonius
B.V., 1998), data reduction Denzo-SMN (Otwinowski, Z.;
Minor, W. Methods in Enzymology 1997, 276, 307–326),
absorption correction data SORTAV (Blessing, R. H. Acta
Crystallogr. 1995, A51, 33–37; Blessing, R. H. J. Appl. Cryst.
1997, 30, 421–426), structure solution SHELXS-97
(Sheldrick, G. M. Acta Crystallogr. 1990, A46, 467–473),
structure refinement SHELXL-97 (Sheldrick, G. M. Universi-
References and notes
1. (a) Ruhemann, S. Trans. Chem. Soc. 1910, 97, 1438.
(b) MacFadyen, D. A.; Fowler, N. J. Biol. Chem. 1950, 186,
´
13. (c) Joullie, M. M.; Thompson, T. R. Tetrahedron 1991, 47,
¨
¨
tat Gottingen, 1997), graphics SCHAKAL (Keller, E. 1997).
Crystallographic data (excluding structure factors) for the
structures reported in this paper have been deposited with the
Cambridge Crystallographic Data Centre as supplementary
publication CCDC-240992, 240993, 233350, 240994, and
240995. Copies of the data can be obtained free of charge on
application to The Director, CCDC, 12 Union Road, Cam-
bridge CB2 1EZ, UK [fax: int. code C44-1223-336-033, e-
mail: deposit@ccdc.cam.ac.uk].
8791. (d) Schertz, T. D.; Reiter, R. C.; Stevenson, C. D. J. Org.
Chem. 2001, 66, 7596.
2. Das, S.; Pramanik, A. Unpublished work.
3. (a) Campagna, F.; Carotti, A.; Casini, G.; Ferappi, M. Gazz.
Chim. Ital. 1983, 113, 507. (b) Schoenberg, A.; Singer, E.
Chem. Ber. 1970, 103, 3871.
4. (a) Peet, N. P.; Huber, E. W.; Huffman, J. C. J. Heterocycl.
Chem. 1995, 32, 33. (b) Black, D. St. C.; Bowyer, M. C.;
Condie, G. C.; Craig, D. C.; Kumar, N. Tetrahedron 1994, 50,
10983. (c) Kundu, S. K.; Pramanik, A.; Patra, A. Synlett 2002,
5, 823. (d) Bullington, J. L.; Dodd, J. H. J. Org. Chem. 1993,
58, 4833. (e) Usmani, J. N.; Ismail, S. M. Pak. J. Sci. Ind. Res.
1987, 30, 89.
12. Green, G. R.; Evans, J. M.; Vong, A. K. Comprehensive
Heterocyclic Chemistry; Katritzky, A. R., Rees, C. W.,
Seriven, E. F. V., Eds.; Pergamon: New York, 1996; Vol. 5,
pp 469–500.
13. (a) Vanags, G.; Duburs, G. Zhurnal Obshchei Khimii 1957, 27,
2729. (b) Panashchenko, A. D. Farmakol. i Toksikol 1956, 19,
17. (c) Vanags, G.; Giller, S.; Geita, L.; Bleksmit, Z. D.;
Kovalenko, V. N.; Kotovshchikova, M. A. Farmakol. i
Toksikol 1956, 19, 23.
5. Kundu, S. K.; Patra, A.; Pramanik, A. Indian J. Chem. 2004,
43B, 604.
6. (a) Poupelin, J.-P.; Saint-Ruf, G.; Perche, J.-C.; Laude, B.;
Narcisse, G.; Bakri-Logesis, F.; Hubert, F. Eur. J. Med. Chem.
1980, 15, 253. (b) Poupelin, J.-P.; Saint-Ruf, G.; Perche, J.-C.;