Chemical transformation of Baylis-Hillman adducts: The reaction of methyl 3-arylamino-2-methylene-3-phenylpropanoates in polyphosphoric acid

Article abstract of DOI:10.1016/j.tet.2004.11.082

We synthesized some interesting compounds including 3-benzylidene-3,4- dihydro-1H-quinolin-2-one, 3-benzylquinolin-2-ol, 4-amino-2-benzylideneindan-1- one, and 1-amino-9a,10-dihydro-4bH-indeno[1,2-a]inden-9-one skeletons starting from Baylis-Hillman adducts.

Full text of DOI:10.1016/j.tet.2004.11.082

Tetrahedron 61 (2005) 1493–1499
Chemical transformation of Baylis–Hillman adducts: the reaction
of methyl 3-arylamino-2-methylene-3-phenylpropanoates
in polyphosphoric acid
Chang Gon Lee,a Ka Young Lee,a Sangku Leeb and Jae Nyoung Kima,
*
aDepartment of Chemistry and Institute of Basic Science, Chonnam National University, Gwangju 500-757, South Korea
bKorea Research Institute of Bioscience and Biotechnology, 52 Oun, Yusong, Taejon 305-333, South Korea
Received 8 November 2004; accepted 26 November 2004
Available online 22 December 2004
Abstract—We synthesized some interesting compounds including 3-benzylidene-3,4-dihydro-1H-quinolin-2-one, 3-benzylquinolin-2-ol,
4-amino-2-benzylideneindan-1-one, and 1-amino-9a,10-dihydro-4bH-indeno[1,2-a]inden-9-one skeletons starting from Baylis–Hillman
adducts.
q 2004 Elsevier Ltd. All rights reserved.
1. Introduction
with polyphosphoric acid (PPA) resulted the formation
of 4b,5,10a,11-tetrahydroindeno[1,2-b]quinolin-10-one
derivatives in moderate yields via the consecutive 1,3-H
transfer, protonation, cyclization, and the final Friedel–
Crafts reaction sequences.3
Recently, the chemical transformations of the Baylis–
Hillman adducts have been studied extensively by us and
other groups.1,2 Among them synthesis of heterocyclic
compounds has received much attention including quino-
lines,2j,l dihydroquinolines,2k and pyrazoles.2f More
recently, we reported the synthesis of 4b,5,10a,11-tetrahy-
droindeno[1,2-b]quinolin-10-one derivatives from 2-aryl-
aminomethylcinnamates, which were made from the
acetates of the Baylis–Hillman adducts (Scheme 1).3 In
the reaction, treatment of the 2-arylaminomethylcinnamates
During the investigation we decided to examine the reaction
of 2 in PPA as shown in Scheme 2. The synthesis of starting
materials 2 was carried out from the acetates of the Baylis–
Hillman adducts 1 according to the reported method
involving the use of DABCO salt concept.4 We tried the
reaction of 2a in PPA, and we isolated 3-benzylidene-3,4-
dihydro-1H-quinolin-2-one (3a) in 79% yield. This com-
pound might be generated via the following mechanism as
shown in Scheme 3: (1) Claisen rearrangement5 of the
aniline moiety of 2a to the primary position to give the
corresponding intermediate 7 and (2) amide bond formation.
Similarly, we prepared some 3-arylidene-3,4-dihydro-1H-
quinolin-2-one derivatives 3b–d in good yields as shown in
Table 1.6 During the synthesis of 3a we observed the
formation of trace amounts of 3-benzylquinolin-2-ol (4a),6
which might be formed via double bond isomerization
and tautomerization sequences from 3a. Such conversion of
3a–d into 4a–d was carried out effectively in high yields by
treatment of 3a–d with DBU in THF at room temperature in
short time (Table 1).
Scheme 1.
However, when we used 2e as the starting material we
could not detect any appreciable amounts of the expected
3-benzylidene-3,4-dihydro-1H-quinolin-2-one compound.
Instead, we could isolate two types of major products,
Keywords: Baylis–Hillman adducts; Polyphosphoric acid (PPA); Quinolin-
2-ones; Quinolin-2-ols; Indan-1-ones; Indeno[1,2-a]inden-9-ones.
* Corresponding author. Tel.: C82 62 530 3381; fax: C82 62 530 3389;
e-mail: kimjn@chonnam.ac.kr
0040–4020/$ - see front matter q 2004 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tet.2004.11.082

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C. G. Lee et al. / Tetrahedron 61 (2005) 1493–1499
Scheme 2.
Scheme 3.
which have the structures of 5a and 6a based on their
spectroscopic data. The formation of 4-amino-2-benzyl-
idene-7-methylindan-1-one (5a, 57%)7 and 1-amino-4-
methyl-9a,10-dihydro-4bH-indeno[1,2-a]inden-9-one (6a,
18%, NOE results of 6a was summarized in Fig. 1)8 could
be explained as shown in Scheme 3. The compound 5a was
generated from the Claisen rearrangement intermediate 7
via intramolecular Friedel–Crafts acylation (pathway a).
The compound 6a might be produced from the same
intermediate 7 via Michael type addition (pathway b)9 and
the following Friedel–Crafts reaction. Similarly, when we
used 2f–h as the starting materials we obtained similar
results (Table 2). The reaction mechanism for the formation
of 6 was further confirmed indirectly by the isolation of the
corresponding intermediate 8 in low yield (29% of 8
together with 59% of 5d and 6% of 6d when we stopped the
reaction after 3 h) when we carried out the reaction with 2h,
fortunately.
The intermediate 7 has two major nucleophilic sites (amino

C. G. Lee et al. / Tetrahedron 61 (2005) 1493–1499
1495
Table 1. Synthesis of quinolones 3 and quinolinols 4
Entry
1
Substrate (%)a
Quinolone 3 (%)b
Quinolinol 4 (%)c
2
3
4
a The corresponding Baylis–Hillman acetate, aq THF, DABCO (1.1 equiv), 30 min, then aniline derivative (1 equiv), rt, 18 h.
b PPA, 80–90 8C, 7 h.
c DBU (0.1 equiv), THF, rt, 1 h.
2. Experimental
2.1. General procedure
1H NMR (300 MHz) and 13C NMR (75 MHz) spectra were
recorded in CDCl3 or in CDCl3CDMSO-d6. The signal
positions are reported in ppm relative to TMS (d scale) used
as an internal standard. The separations were carried out by
flash column chromatography over silica gel (230–400 mesh
ASTM). Organic extracts were dried over anhydrous
MgSO4 and the solvents were evaporated on a rotary
evaporator under water aspirator pressure. IR spectra are
reported in cmK1. Mass spectra were obtained from the
Korea Basic Science Institute (Gwangju branch). Melting
points are uncorrected. The combustion analyses were
carried out at Korea Research Institute of Chemical
Technology, Taejon, Korea. The starting materials 2a–h
were prepared according to the published method from the
acetates of the Baylis–Hillman adducts and aniline deriva-
tives via the corresponding DABCO salts.4 Identification of
starting materials was carried out with their 1H NMR and/or
13C NMR spectra simply.
Figure 1. NOE results of compound 6a.
group and the ortho-position of the aniline moiety) and two
major electrophilic sites (ester moiety and the b-position of
the methyl cinnamate backbone). For the intermediates 7
derived from 2a–d, the major pathway is the attack of the
amino group toward ester moiety.10 For the intermediates 7
derived from 2e–h, the major route is the attack of the ortho-
position of aniline moiety to ester group (pathway a) and the
minor is the attack of the ortho-position to the vinyl carbon
at the b-position of cinnamate skeleton (pathway b).11 The
subtle difference of the electron density at the aniline moiety
caused such a strikingly different results. For the reason,
however, we cannot explain definitively at this point.
In conclusion, we synthesized 3-benzylidene-3,4-dihydro-
1H-quinolin-2-one, 3-benzylquinolin-2-ol, 4-amino-2-ben-
zylideneindan-1-one, and 1-amino-9a,10-dihydro-4bH-
indeno[1,2-a]inden-9-one skeletons starting from Baylis–
Hillman adducts. We also found that the slight differences in
the electron density of the aniline moiety may cause
strikingly different reaction pathways.
2.2. Typical procedure for the synthesis of quinolone 3a
A stirred mixture of 2a (174 mg, 0.65 mmol) in PPA (2 g)
was heated to 80–90 8C for 7 h. The reaction mixture was
poured into cold water, extracted with EtOAc, washed with
NaHCO3 solution, drying with MgSO4, removal of solvent,
and after column chromatographic purification process

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C. G. Lee et al. / Tetrahedron 61 (2005) 1493–1499
Table 2. Synthesis of indanones 5 and indenoindenones 6
Entry
1
Substrate (%)a
Indanone 5 (%)b
Indenoindenone 6 (%)b
2
3
4
a The corresponding Baylis–Hillman acetate, aq THF, DABCO (1.1 equiv), 30 min, then aniline derivative (1 equiv), rt, 18 h.
b PPA, 80–90 8C. 15 h.
(hexanes/EtOAcZ3:2), we obtained 3a as a yellow solid,
121 mg (79%). The spectroscopic data of prepared com-
pounds are as follows.
6H), 7.86 (t, JZ2.4 Hz, 1H), 8.50 (br s, 1H); 13C NMR
(CDCl3) d 21.63, 30.65, 115.33, 121.46, 123.13, 127.62,
128.02, 128.43, 129.47, 130.29, 132.78, 136.18, 137.81,
139.16, 166.19. Mass (70 eV) m/z (rel. intensity) 116 (17),
232 (32), 249 (MC, 100).
2.2.1. Compound 3a. Yield 79%; yellow solid, mp 174–
1
175 8C; IR (CH2Cl2) 3197, 1666, 1593, 1377 cmK1; H
NMR (CDCl3) d 4.11 (d, JZ2.4 Hz, 2H), 6.88–7.19 (m,
4H), 7.34–7.47 (m, 5H), 7.90 (t, JZ2.4 Hz, 1H), 9.27 (br s,
1H); 13C NMR (CDCl3) d 30.58, 115.52, 121.39, 123.12,
127.29, 127.69, 128.36, 128.71, 128.85, 130.16, 135.65,
136.31, 137.64, 166.30. Mass (70 eV) m/z (rel. intensity) 77
(32), 89 (27), 117 (32), 204 (16), 216 (36), 218 (32), 234
(100), 235 (MC, 89). Anal. Calcd for C16H13NO: C, 81.68;
H, 5.57; N, 5.95. Found: C, 81.60; H, 5.61; N, 5.92.
2.2.4. Compound 3d. Yield 80%; pale yellow solid, mp
207–208 8C; IR (KBr) 3359, 3186, 1674, 1597, 1493 cmK1
;
1H NMR (CDCl3CDMSO-d6) d 4.05 (d, JZ2.7 Hz, 2H),
6.89–6.96 (m, 2H), 7.09–7.16 (m, 2H), 7.36–7.44 (m, 4H),
7.75 (t, JZ2.7 Hz, 1H), 9.66 (s, 1H); 13C NMR (CDCl3C
DMSO-d6) d 29.97, 114.92, 120.23, 122.12, 126.97, 127.56,
127.82, 128.27, 130.69, 133.55, 133.84, 134.66, 136.07,
164.54.
2.2.2. Compound 3b. Yield 78%; yellow solid, mp 205–
2.3. Typical procedure for the conversion of quinolone
3a into quinolinol 4a
1
206 8C; IR (KBr) 1666, 1500 cmK1; H NMR (CDCl3C
DMSO-d6) d 4.06 (d, JZ2.1 Hz, 2H), 6.89 (d, JZ8.4 Hz,
1H), 7.05 (m, 2H), 7.38–7.49 (m, 5H), 7.78 (t, JZ2.4 Hz,
1H), 10.01 (br s, 1H); 13C NMR (CDCl3CDMSO-d6) d
29.66, 116.05, 122.12, 126.21, 126.34, 126.62, 127.23,
128.01, 128.12, 129.27, 134.70, 135.08, 136.19, 164.39.
Anal. Calcd for C16H12ClNO: C, 71.25; H, 4.48; N, 13.14.
Found: C, 71.38; H, 4.59; N, 13.02.
To a stirred solution of 3a (146 mg, 0.62 mmol) in THF
(2 mL) was added DBU (9 mg, 0.06 mmol) and the reaction
mixture was stirred at room temperature for 1 h. After the
usual workup and column chromatographic purification
process (hexanes/EtOAcZ1:1), desired 4a was obtained,
136 mg (93%). The spectroscopic data of prepared com-
pounds are as follows.
2.2.3. Compound 3c. Yield 73%; yellow solid, mp 187–
188 8C; IR (CH2Cl2) 3398, 1651 cmK1; 1H NMR (CDCl3) d
2.41 (s, 3H), 4.11 (d, JZ2.1 Hz, 2H), 6.81 (dd, JZ7.8,
0.6 Hz, 1H), 6.96 (td, JZ7.8, 1.5 Hz, 1H), 7.12–7.38 (m,
2.3.1. Compound 4a. Yield 93%; white solid, mp 196–
197 8C (Lit.6f 199–200 8C); IR (CH2Cl2) 3467, 1658 cmK1
;
1H NMR (CDCl3) d 4.03 (d, JZ0.9 Hz, 2H), 7.15 (td, JZ

C. G. Lee et al. / Tetrahedron 61 (2005) 1493–1499
1497
7.2, 1.2 Hz, 1H), 7.22–7.35 (m, 6H), 7.41–7.46 (m, 3H),
11.85 (br s, 1H); 13C NMR (CDCl3) d 36.39, 115.78, 120.38,
122.64, 126.61, 127.50, 128.77, 129.64, 129.83, 133.70,
137.70, 137.73, 139.38, 164.22. Mass (70 eV) m/z (rel.
intensity) 76 (25), 116 (35), 216 (27), 234 (100), 235 (MC,
91). Anal. Calcd for C16H13NO: C, 81.68; H, 5.57; N, 5.95.
Found: C, 81.85; H, 5.73; N, 5.87.
(CDCl3) d 29.56, 56.31, 111.04, 122.17, 126.71, 129.07,
129.58, 130.75, 133.17, 134.82, 135.78, 136.48, 136.97,
152.20, 192.53. Mass (70 eV) m/z (rel. intensity) 66 (10), 77
(30), 110 (32), 174 (100), 236 (41), 265 (MC, 87). Anal.
Calcd for C17H15NO2: C, 76.96; H, 5.70; N, 5.28. Found: C,
76.93; H, 5.92; N, 5.33.
2.4.3. Compound 5c. Yield 59%; yellow solid, mp 205–
1
206 8C; IR (KBr) 3448, 3363, 1685, 1624 cmK1; H NMR
2.3.2. Compound 4b. Yield 92%; white solid, mp 235–
236 8C; IR (KBr) 3155, 1674, 1485 cmK1 1H NMR
;
(CDCl3) d 2.13 (s, 3H), 2.29 (s, 3H), 3.64 (s, 2H), 3.73 (br s,
2H), 7.20 (s, 1H), 7.34–7.47 (m, 3H), 7.59–7.65 (m, 3H);
13C NMR (CDCl3) d 13.65, 21.03, 29.45, 115.62, 127.12,
129.06, 129.62, 130.76, 133.04, 133.22, 135.31, 135.73,
136.04, 137.48, 141.40, 194.67. Mass (70 eV) m/z (rel.
intensity) 123 (13), 220 (37), 263 (MC, 100).
(CDCl3CDMSO-d6) d 3.94 (s, 2H), 7.21–7.39 (m, 9H),
11.66 (s, 1H); 13C NMR (CDCl3CDMSO-d6) d 35.89,
116.69, 120.72, 126.12, 126.33, 126.80, 128.47, 129.24,
129.25, 135.10, 135.53, 136.26, 138.65, 162.71. Anal. Calcd
for C16H12ClNO: C, 71.25; H, 4.48; N, 13.14. Found: C,
71.33; H, 4.45; N, 13.32.
2.4.4. Compound 5d. Yield 60%; yellow solid, mp 166–
2.3.3. Compound 4c. Yield 88%; white solid, mp 197–
1
167 8C; IR (KBr) 3397, 3328, 1685, 1631, 1504 cmK1; H
1
198 8C; IR (CH2Cl2) 1655, 1570, 1431 cmK1; H NMR
NMR (CDCl3) d 3.54 (br s, 2H), 3.69 (s, 2H), 3.91 (s, 3H),
3.92 (s, 3H), 6.35 (s, 1H), 7.31–7.63 (m, 6H); 13C NMR
(CDCl3) d 29.44, 56.14, 56.42, 94.61, 119.46, 125.55,
128.94, 129.20, 130.56, 131.68, 135.77, 135.91, 136.06,
153.14, 153.40, 191.24. Mass (70 eV) m/z (rel. intensity)
204 (32), 236 (12), 266 (68), 295 (MC, 100).
(CDCl3) d 2.34 (s, 3H), 3.98 (s, 2H), 7.12–7.25 (m, 5H),
7.32–7.46 (m, 4H), 11.97 (br s, 1H); 13C NMR (CDCl3) d
21.29, 35.93, 115.84, 120.42, 122.57, 127.44, 129.46,
129.52, 129.72, 133.90, 136.08, 136.23, 137.59, 137.70,
164.34. Mass (70 eV) m/z (rel. intensity) 77 (98), 123 (13),
216 (10), 232 (35), 249 (MC, 100).
2.4.5. Compound 6a. Yield 18%; yellow solid, mp 177–
2.3.4. Compound 4d. Yield 89%; white solid, mp 221–
1
178 8C; IR (CH2Cl2) 3429, 3352, 1708, 1496 cmK1; H
1
222 8C; IR (KBr) 3302, 3155, 1670, 1570, 1489 cmK1; H
NMR (CDCl3) d 2.56 (s, 3H), 2.90–3.24 (m, 2H), 3.44 (br s,
2H), 3.60–3.68 (m, 1H), 5.01 (d, JZ7.2 Hz, 1H), 6.48 (d,
JZ8.1 Hz, 1H), 6.89 (dd, JZ7.8, 0.6 Hz, 1H), 7.34–7.39
(m, 1H), 7.54–7.60 (m, 1H), 7.74 (d, JZ1.2 Hz, 1H), 7.77
(d, JZ0.6 Hz, 1H); 13C NMR (CDCl3) d 20.44, 31.78,
51.47, 51.80, 114.45, 123.91, 124.53, 127.05, 127.24,
128.06, 130.22, 135.12, 136.28, 140.86, 142.45, 156.47,
208.59. Mass (70 eV) m/z (rel. intensity) 76 (18), 102 (32),
206 (30), 234 (28), 249 (MC, 100). Anal. Calcd for
C17H15NO: C, 81.90; H, 6.06; N, 5.62. Found: C, 81.95; H,
6.00; N, 5.78.
NMR (CDCl3CDMSO-d6) d 3.92 (s, 2H), 7.09–7.49 (m,
9H), 11.59 (s, 1H); 13C NMR (CDCl3CDMSO-d6) d 35.18,
115.05, 119.44, 121.70, 126.85, 128.19, 129.18, 130.31,
131.55, 132.68, 136.78, 137.63, 137.64, 162.62.
2.4. Typical procedure for the preparation of indanone
5a and indenoindenone 6a
A mixture of 2e (218 mg, 0.78 mmol) and PPA (2 g) was
heated to 80–90 8C for 15 h. The reaction mixture was
poured into cold water, extracted with EtOAc, washed with
NaHCO3 solution, drying with MgSO4, removal of solvent
and after column chromatographic purification process
(hexanes/EtOAcZ2:1), we obtained 5a (110 mg, 57%)
and 6a (35 mg, 18%). The spectroscopic data of prepared
compounds are as follows.
2.4.6. Compound 6b. Yield 13%; yellow solid, mp
163–164 8C; IR (KBr) 3460, 3410, 3359, 1712, 1601,
1
1496 cmK1; H NMR (CDCl3) d 3.01–3.26 (m, 2H), 3.13–
3.34 (br s, 2H), 3.58–3.66 (m, 1H), 3.87 (s, 3H), 5.11 (d, JZ
7.2 Hz, 1H), 6.50 (dd, JZ8.4, 0.6 Hz, 1H), 6.58–6.61 (m,
1H), 7.34 (t, JZ7.5 Hz, 1H), 7.57 (td, JZ7.2, 1.2 Hz, 1H),
7.71 (d, JZ7.5 Hz, 1H), 8.04 (dd, JZ8.1, 0.9 Hz, 1H); 13C
NMR (CDCl3) d 32.01, 50.22, 51.11, 55.65, 110.48, 114.83,
123.97, 127.94, 128.47, 129.48, 131.42, 135.17, 136.13,
136.55, 149.85, 157.27, 209.22. Mass (70 eV) m/z (rel.
intensity) 76 (12), 83 (46), 96 (53), 110 (49), 165 (18), 204
(19), 222 (27), 250 (83), 265 (MC, 100). Anal. Calcd for
C17H15NO2: C, 76.96; H, 5.70; N, 5.28. Found: C, 77.03; H,
5.68; N, 5.31.
2.4.1. Compound 5a. Yield 57%; yellow solid, mp 169–
1
170 8C; IR (KBr) 3413, 3332, 1689, 1631 cmK1; H NMR
(CDCl3) d 2.36 (s, 3H), 3.72 (br s, 2H), 3.74 (d, JZ1.8 Hz,
2H), 6.80 (d, JZ7.8 Hz, 1H), 6.99 (dd, JZ8.1, 0.9 Hz, 1H),
7.36–7.48 (m, 3H), 7.54 (t, JZ2.4 Hz, 1H), 7.66 (d, JZ
6.9 Hz, 2H); 13C NMR (CDCl3) d 17.83, 29.24, 119.82,
129.08, 129.30, 129.61, 130.67, 130.76, 133.24, 135.04,
135.56, 135.80, 135.93, 141.16, 193.66. Mass (70 eV) m/z
(rel. intensity) 77 (12), 102 (28), 117 (47), 144 (29), 172
(26), 206 (30), 220 (24), 232 (27), 249 (MC, 100). Anal.
Calcd for C17H15NO: C, 81.90; H, 6.06; N, 5.62. Found: C,
81.79; H, 6.13; N, 5.57.
2.4.7. Compound 6c. Yield 14%; yellow solid, mp 173–
174 8C; IR (KBr) 1712, 1647, 1466 cmK1 1H NMR
;
(CDCl3) d 2.01 (s, 3H), 2.25 (s, 3H), 3.05–3.24 (m, 2H),
3.54 (br s, 2H), 3.57–3.64 (m, 1H), 4.90 (d, JZ7.5 Hz, 1H),
6.77 (s, 1H), 7.31–7.37 (m, 1H), 7.59–7.77 (m, 3H); 13C
NMR (CDCl3) d 12.72, 21.10, 31.51, 51.31, 51.48, 115.96,
119.26, 124.19, 124.38, 125.90, 128.02, 135.45, 135.99,
136.69, 140.92, 141.02, 157.65, 209.36. Mass (70 eV) m/z
2.4.2. Compound 5b. Yield 61%; yellow solid, mp 212–
1
213 8C; IR (KBr) 3413, 3344, 1685, 1631, 1496 cmK1; H
NMR (CDCl3) d 3.57 (br s, 2H), 3.76 (d, JZ2.1 Hz, 2H),
3.92 (s, 3H), 6.73 (d, JZ8.4 Hz, 1H), 6.91 (d, JZ8.7 Hz,
1H), 7.36–7.48 (m, 3H), 7.61–7.68 (m, 3H); 13C NMR

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C. G. Lee et al. / Tetrahedron 61 (2005) 1493–1499
(rel. intensity) 108 (12), 202 (11), 220 (31), 246 (48), 263
(MC, 100).
References and notes
1. For the review articles of Baylis–Hillman reaction, see
(a) Basavaiah, D.; Rao, A. J.; Satyanarayana, T. Chem. Rev.
2003, 103, 811. (b) Kim, J. N.; Lee, K. Y. Curr. Org. Chem.
2002, 6, 627. (c) Basavaiah, D.; Rao, P. D.; Hyma, R. S.
Tetrahedron 1996, 52, 8001. (d) Ciganek, E. In Organic
Reactions, Vol. 51; Wiley: New York, 1997; pp 201–350.
(e) Drewes, S. E.; Roos, G. H. P. Tetrahedron 1988, 44, 4653.
(f) Langer, P. Angew. Chem., Int. Ed. Engl. 2000, 39, 3049.
(g) Xu, Y.-M.; Shi, M. J. Org. Chem. 2004, 69, 417.
2.4.8. Compound 6d. Yield 17%; yellow solid, mp 179–
1
180 8C; IR (KBr) 3433, 3359, 1705, 1600, 1500 cmK1; H
NMR (CDCl3) d 1.60 (br s, 2H), 3.03–3.10 (m, 1H), 3.18–
3.27 (m, 1H), 3.59–3.67 (m, 1H), 3.82 (s, 3H), 3.89 (s, 3H),
5.07 (d, JZ7.2 Hz, 1H), 6.37 (s, 1H), 7.33 (t, JZ7.2 Hz,
1H), 7.57 (td, JZ7.2, 1.23 Hz, 1H), 7.70 (d, JZ7.8 Hz, 1H),
7.79–8.02 (m, 1H); 13C NMR (CDCl3) d 31.91, 49.60,
511.62, 56.00, 56.43, 95.73, 123.09, 124.01, 125.84, 127.87,
128.34, 129.46, 135.17, 136.08, 147.63, 149.00, 157.72,
209.29. Mass (70 eV) m/z (rel. intensity) 220 (11), 252 (14),
277 (82), 295 (MC, 100).
2. For our recent publications on Baylis–Hillman chemistry, see:
(a) Lee, M. J.; Lee, K. Y.; Lee, J. Y.; Kim, J. N. Org. Lett.
2004, 6, 3313. (b) Gowrisankar, S.; Lee, C. G.; Kim, J. N.
Tetrahedron Lett. 2004, 45, 6949. (c) Gowrisankar, S.; Lee,
K. Y.; Lee, C. G.; Kim, J. N. Tetrahedron Lett. 2004, 45, 6141.
(d) Lee, K. Y.; Gowrisankar, S.; Kim, J. N. Tetrahedron Lett.
2004, 45, 5485. (e) Kim, J. M.; Lee, K. Y.; Lee, S. k.; Kim,
J. N. Tetrahedron Lett. 2004, 45, 2805. (f) Lee, K. Y.; Kim,
J. M.; Kim, J. N. Tetrahedron Lett. 2003, 44, 6737. (g) Kim,
J. N.; Kim, J. M.; Lee, K. Y. Synlett 2003, 821. (h) Im, Y. J.;
Lee, C. G.; Kim, H. R.; Kim, J. N. Tetrahedron Lett. 2003, 44,
2987. (i) Lee, K. Y.; Kim, J. M.; Kim, J. N. Synlett 2003, 357.
(j) Lee, K. Y.; Kim, J. M.; Kim, J. N. Tetrahedron 2003, 59,
385. (k) Kim, J. N.; Kim, H. S.; Gong, J. H.; Chung, Y. M.
Tetrahedron Lett. 2001, 42, 8341. (l) Kim, J. N.; Chung, Y. M.;
Im, Y. J. Tetrahedron Lett. 2002, 43, 6209.
2.4.9. Spectroscopic data of the intermediate 8 derived
from 2h. Yield 29%, mp 68–69 8C; IR (CH2Cl2) 3448,
1
3363, 1732, 1597, 1504 cmK1; H NMR (CDCl3) d 3.12–
3.16 (m, 1H), 3.18 (br s, 2H), 3.20–3.26 (m, 2H), 3.49 (s,
3H), 3.70 (s, 3H), 3.84 (s, 3H), 4.44 (d, JZ4.5 Hz, 1H), 6.34
(s, 1H), 7.09–7.27 (m, 5H); 13C NMR (CDCl3) d 32.45,
52.22, 52.46, 53.71, 56.29, 56.62, 96.92, 124.52, 125.53,
126.37, 127.42, 128.41, 129.33, 145.04, 147.67, 148.92,
175.46. Mass (70 eV) m/z (rel. intensity) 133 (14), 165 (11),
252 (40), 327 (MC, 100).
2.4.10. Spectroscopic data of the Claisen rearrangement
intermediate 7 derived from 2b. The corresponding
Claisen rearrangement intermediate 7 could be isolated in
40% yield, fortunately, when we carried out the reaction of
2b in PPA (90 8C) in short time (60 min). This compound
was prepared more effectively in 95% isolated yield when
we carried out the reaction at low temperature in PPA
(60 8C) for 80 min as a pale yellow solid,10 mp 124–125 8C;
3. Lee, C. G.; Lee, K. Y.; Gowrisankar, S.; Kim, J. N.
Tetrahedron Lett. 2004, 45, 7409.
4. For the introduction of nucleophiles at the secondary position
of Baylis–Hillman adducts by using the DABCO salt concept,
see: (a) Kim, J. N.; Lee, H. J.; Lee, K. Y.; Gong, J. H. Synlett
2002, 173. (b) Gong, J. H.; Kim, H. R.; Ryu, E. K.; Kim, J. N.
Bull. Korean Chem. Soc. 2002, 23, 789. (c) Kim, J. M.; Lee,
K. Y.; Kim, J. N. Bull. Korean Chem. Soc. 2004, 25, 328.
(d) Chung, Y. M.; Gong, J. H.; Kim, T. H.; Kim, J. N.
Tetrahedron Lett. 2001, 42, 9023. (e) Im, Y. J.; Kim, J. M.;
Mun, J. H.; Kim, J. N. Bull. Korean Chem. Soc. 2001, 22, 349.
5. (a) Castro, A. M. M. Chem. Rev. 2004, 104, 2939. (b) Foucaud,
A.; Brine, N. Synth. Commun. 1994, 24, 2851.
1
IR (KBr) 3460, 3383, 3190, 1670, 1597, 1496 cmK1; H
NMR (CDCl3) d 3.66 (s, 2H), 3.70 (br s, 2H), 3.79 (s, 3H),
6.61 (d, JZ8.4 Hz, 1H), 6.87 (d, JZ2.4 Hz, 1H), 6.99 (dd,
JZ8.4, 2.4 Hz, 1H), 7.25–7.43 (m, 5H), 7.98 (s, 1H); 13C
NMR (CDCl3) d 28.75, 52.51, 116.97, 123.64, 125.57,
127.28, 128.07, 128.94, 129.21, 129.38, 129.52, 135.15,
142.04, 143.19, 168.59.
6. For the synthesis and biological activities of 2-quinolone and
2-quinolinol derivatives, see (a) Kadnikov, D. V.; Larock,
R. C. J. Organomet. Chem. 2003, 687, 425. (b) Cortese, N. A.;
Ziegler, C. B. Jr.; Hrnjez, B. J.; Heck, R. F. J. Org. Chem.
1978, 43, 2952. (c) Terpko, M. O.; Heck, R. F. J. Am. Chem.
Soc. 1979, 101, 5281. (d) Hirao, K.; Morii, N.; Joh, T.;
Takahashi, S. Tetrahedron Lett. 1995, 36, 6243. (e) Li, H.;
Yang, H.; Petersen, J. L.; Wang, K. K. J. Org. Chem. 2004, 69,
4500. (f) Averamoff, M.; Sprinzak, Y. J. J. Am. Chem. Soc.
1956, 78, 4090.
2.4.11. Spectroscopic data of the Claisen rearrangement
intermediate 7 derived from 2e. The corresponding
Claisen rearrangement intermediate 7 could be isolated in
39% yield when we carried out the reaction at low
temperature in PPA (60 8C) for 60 min as a yellow solid,11
mp 210–211 8C; IR (KBr) 1712, 1628, 1504 cmK1 1H
;
NMR (CDCl3) d 2.17 (s, 3H), 3.57 (br s, 2H), 3.69 (s, 2H),
3.77 (s, 3H), 6.61 (d, JZ7.8 Hz, 1H), 6.73 (s, 1H), 6.90 (d,
JZ7.8 Hz, 1H), 7.30–7.39 (m, 5H); 13C NMR (CDCl3) d
20.83, 28.74, 52.43, 116.07, 123.98, 127.89, 128.25, 128.74,
128.84, 128.99, 129.49, 130.46, 135.46, 141.38, 141.98,
168.95.
7. For the synthesis and reactions of 2-benzylidene-1-indanone
derivatives, see (a) Berthelette, C.; McCooye, C.; Leblanc, Y.;
Trimble, L. A. J. Org. Chem. 1997, 62, 4339. (b) Lee, H. J.;
Kim, T. H.; Kim, J. N. Bull. Korean Chem. Soc. 2001, 22,
1063. (c) Houlihan, W. J.; Shapiro, M. J.; Chin, J. A. J. Org.
Chem. 1997, 62, 1529. (d) Basavaiah, D.; Reddy, R. M.
Tetrahedron Lett. 2001, 42, 3025. (e) Shih, H.; Deng, L.;
Carrera, C. J.; Adachi, S.; Cottam, H. B.; Carson, D. A. Bioorg.
Med. Chem. Lett. 2000, 10, 487.
Acknowledgements
8. For the synthesis and chemistry of indeno[1,2-a]indenone
derivatives, see (a) Anstead, G. M.; Srinivasan, R.; Peterson,
C. S.; Wilson, S. R.; Katzenellenbogen, J. A. J. Am. Chem.
Soc. 1991, 113, 1378. (b) Laarhoven, W. H.; Lijten, F. A. T.;
This work was supported by the grant (R05-2003-000-
10042-0) from the Basic Research Program of the Korea
Science and Engineering Foundation.

C. G. Lee et al. / Tetrahedron 61 (2005) 1493–1499
1499
Smits, J. M. M. J. Org. Chem. 1985, 50, 3208. (c) Cristol, S. J.;
Jarvis, B. B. J. Am. Chem. Soc. 1967, 89, 401. (d) Barnes,
R. A.; Beitchman, B. D. J. Am. Chem. Soc. 1954, 76, 5430.
(e) Eckrich, R.; Kuck, D. Synlett 1993, 344. (f) Woning, J.;
Lijten, F. A. T.; Laarhoven, W. H. J. Org. Chem. 1991, 56,
2427.
(d) Skuballa, W.; Raduchel, B.; Loge, O.; Elger, W.;
Vorbruggen, H. J. Med. Chem. 1978, 21, 443.
10. The corresponding Claisen rearrangement intermediate 7 was
prepared in 95% isolated yield when we carried out the
reaction of 2b in PPA at 60 8C for 80 min (see Section 2). This
compound was converted to 3b in 90% yield under the typical
experimental conditions (PPA, 80–90 8C, 7 h).
11. The corresponding Claisen rearrangement intermediate 7
could be also prepared from 2e in 39% yield (PPA, 60 8C,
60 min) together with 5a (58%). For the spectroscopic data of
the intermediate 7, please see Section 2. This intermediate 7
was converted into 5a (60%) and 6a (15%) under the typical
experimental conditions (PPA, 80–90 8C, 15 h).
9. For similar addition reactions of aromatic compound at the
Michael acceptor, see (a) Noguchi, T.; Onodera, A.;
Tomisawa, K.; Yokomori, S. Chem. Pharm. Bull. 2002, 50,
1407. (b) Gu, X.-H.; Yu, H.; Jacobson, A. E.; Rothman, R. B.;
Dersch, C. M.; George, C.; Flippen-Anderson, J. L.; Rice,
K. C. J. Med. Chem. 2000, 43, 4868. (c) Ogura, K.; Arai, T.;
Kayano, A.; Akazome, M. Tetrahedron Lett. 1998, 39, 9051.