12760
J. Oyamada, T. Kitamura / Tetrahedron 63 (2007) 12754–12762
1
d 1.10 (t, J¼7.1 Hz, 3H, CH ), 2.16 (s, 6H, aryl–CH ), 2.27
oil. H NMR (300 MHz, CDCl ) d 1.12 (t, J¼7.1 Hz, 6H,
3
3
3
(
s, 3H, aryl–CH ), 4.03 (q, J¼7.1 Hz, 2H, OCH ), 6.11 (d,
CH ), 2.05 (s, 3H, aryl–CH ), 2.15 (s, 6H, aryl–CH ), 4.03
3
3
2
3
3
J¼12.0 Hz, 1H, vinyl), 6.84 (s, 2H, aryl), 7.02 (d,
(q, J¼7.1 Hz, 4H, OCH ), 6.12 (d, J¼11.7 Hz, 2H, vinyl),
2
1
3
13
J¼12.0 Hz, 1H, vinyl).
d 13.94, 20.11, 21.01, 59.92, 122.77, 127.78, 132.77,
34.44, 136.65, 144.13, 165.47. Ethyl (2E)-3-(2,4,6-trime-
C NMR (75 MHz, CDCl )
6.88 (s, 1H, aryl), 7.04 (d, J¼11.7 Hz, 2H, vinyl).
C
NMR (75 MHz, CDCl ) d 13.98, 17.66, 20.17, 59.90,
3
3
1
122.68, 128.36, 130.97, 132.98, 133.46, 144.40, 165.38.
2
9
thylphenyl)propenoate was observed with the isomers of
a and 6a in the mixture obtained from the reaction of 3a
3
4.10.8. Ethyl (2Z)-3-{3-bromo-5-[(1Z)-2-ethoxycarbonyl-
ethenyl]-2,4,6-trimethylphenyl}propenoate (4b).
Slightly yellow oil. H NMR (300 MHz, CDCl ) d 1.11 (t,
3
ꢁ
H, CH ), 2.26 (s, 3H, aryl–CH ), 2.33 (s, 6H, aryl–CH ),
1
at 70 C. H NMR (300 MHz, CDCl ) d 1.34 (t, J¼7.2 Hz,
3
1
3
4
3
3
3
.27 (q, J¼7.2 Hz, 2H, OCH ), 6.05 (d, J¼16.2 Hz, 1H, vi-
J¼7.1 Hz, 6H, CH ), 2.02 (s, 3H, aryl–CH ), 2.32 (s, 6H,
2
3
3
nyl), 6.89 (s, 2H, aryl), 7.84 (d, J¼16.2 Hz, 1H, vinyl).
aryl–CH ), 4.02 (q, J¼7.1 Hz, 4H, OCH ), 6.14 (d,
3
2
J¼11.7 Hz, 2H, vinyl), 7.04 (d, J¼11.7 Hz, 2H, vinyl).
1
3
4
.10.2. Ethyl (2Z)-3-(pentamethylphenyl)propenoate
ꢁ
C NMR (75 MHz, CDCl ) d 13.92, 17.82, 21.76, 60.06,
3
8
b,12,13a
1
(
3b).
Colorless crystals. Mp 72–74 C. H NMR
123.24, 125.87, 129.91, 133.52, 134.37, 144.04, 165.11.
MS (EI, m/z) 396, 394 (M ).
+
(
6
300 MHz, CDCl ) d 1.10 (t, J¼7.1 Hz, 3H, CH ), 2.14 (s,
3
3
H, aryl–CH ), 2.20 (s, 6H, aryl–CH ), 2.22 (s, 3H, aryl–
3 3
CH ), 4.01 (q, J¼7.1 Hz, 2H, OCH ), 6.13 (d, J¼12.0 Hz,
4.10.9. Ethyl (2Z)-3-{5-[(1Z)-2-ethoxycarbonylethenyl]-
3-hydroxy-2,4,6-trimethylphenyl}propenoate (4c). Col-
orless crystals. Mp 109–112 C. H NMR (300 MHz,
3
2
1
3
1
H, vinyl), 7.12 (d, J¼12.0 Hz, 1H, vinyl). C NMR
ꢁ
1
(
75 MHz, CDCl ) d 13.96, 16.36, 16.74, 17.59, 59.78,
3
1
22.13, 129.76, 131.89, 133.23, 133.95, 146.46, 165.42.
CDCl ) d 1.12 (t, J¼7.1 Hz, 6H, CH ), 1.99 (s, 3H, aryl–
3
3
CH ), 2.10 (s, 6H, aryl–CH ), 4.03 (q, J¼7.1 Hz, 4H,
3
3
8
b,13a
4.10.3. Ethyl (2Z)-3-(1-naphthyl)propenoate (3c).
Slightly yellow liquid. H NMR (300 MHz, CDCl ) d 1.00
OCH ), 4.53 (s, 1H, OH), 6.14 (d, J¼12.0 Hz, 2H, vinyl),
2
1
13
7.02 (d, J¼12.0 Hz, 2H, vinyl). C NMR (75 MHz,
3
(
6
t, J¼7.1 Hz, 3H, CH ), 4.00 (q, J¼7.1 Hz, 2H, OCH ),
CDCl ) d 13.20, 13.98, 17.33, 59.95, 119.42, 122.87 (two
3
3
2
.24 (d, J¼12.0 Hz, 1H, vinyl), 7.41–7.50 (m, 4H, naphthyl),
peaks overlapped), 133.85, 144.24, 149.44, 165.33. MS
(EI, m/z) 332 (M ). Anal. Calcd for C H O : C, 68.66;
H, 7.28. Found: C, 68.86; H, 7.27.
+
7
.55 (d, J¼12.0 Hz, 1H, vinyl), 7.80–7.91 (m, 3H, naphthyl).
1
9 24 5
1
3
C NMR (75 MHz, CDCl ) d 13.79, 60.11, 122.82, 124.39,
3
1
1
24.96, 125.81, 126.20, 126.49, 128.50, 128.67, 131.07,
33.04, 133.25, 141.79, 165.89.
4.10.10. Diethyl (1E,3Z)-4-(2,4,6-trimethylphenyl)buta-
,3-diene-1,3-dicarboxylate (5a). Slightly yellow oil.
8
b
1
1
4
.10.4. Ethyl (2Z)-3-(2,5-dimethylphenyl)propenoate
Colorless liquid. H NMR (300 MHz, CDCl )
H NMR (300 MHz, CDCl ) d 0.90 (t, J¼7.1 Hz, 3H,
3
8
b,12
1
(
3d).
CH ), 1.31 (t, J¼7.1 Hz, 3H, CH ), 2.15 (s, 6H, aryl–
3
3
3
d 1.14 (t, J¼7.1 Hz, 3H, CH ), 2.23 (s, 3H, aryl–CH ),
CH ), 2.26 (s, 3H, aryl–CH ), 3.99 (q, J¼7.1 Hz, 2H,
3
3
3
3
2
6
7
.29 (s, 3H, aryl–CH ), 4.09 (q, J¼7.1 Hz, 2H, OCH ),
OCH ), 4.24 (q, J¼7.1 Hz, 2H, OCH ), 6.23 (d,
3
2
2
2
.00 (d, J¼12.0 Hz, 1H, vinyl), 6.98–7.08 (m, 2H, aryl),
J¼15.9 Hz, 1H, vinyl), 6.82 (s, 2H, aryl), 7.15 (s, 1H, vinyl),
1
3
13
.08 (d, J¼12.0 Hz, 1H, vinyl), 7.11 (s, 1H, aryl).
C
7.46 (d, J¼15.9 Hz, 1H, vinyl). C NMR (75 MHz, CDCl )
3
NMR (75 MHz, CDCl ) d 13.94, 19.33, 20.88, 60.06,
3
d 13.43, 14.24, 20.08, 20.93, 60.48, 60.69, 120.70, 127.79,
132.04, 134.39, 135.13, 137.28, 141.35, 143.07, 166.02,
166.79.
1
1
20.99, 129.09, 129.26, 129.53, 132.61, 134.46, 134.87,
42.86, 166.09.
4
propenoate (3e).
.10.5. Ethyl (2Z)-3-(3-bromo-2,4,6-trimethylphenyl)-
NMR
4.10.11. Diethyl (1E,3Z)-4-(pentamethylphenyl)buta-1,3-
diene-1,3-dicarboxylate (5b). Slightly yellow crystals.
8
b,13a
1
8b
Colorless liquid.
H
1
(
3
300 MHz, CDCl ) d 1.08 (t, J¼7.1 Hz, 3H, CH ), 2.11 (s,
H NMR (300 MHz, CDCl ) d 0.87 (t, J¼7.1 Hz, 3H,
3
3
3
H, aryl–CH ), 2.30 (s, 3H, aryl–CH ), 2.37 (s, 3H, aryl–
3
CH ), 1.32 (t, J¼7.1 Hz, 3H, CH ), 2.12 (s, 6H, aryl–
3
3
3
CH ), 4.02 (q, J¼7.1 Hz, 2H, OCH ), 6.13 (d, J¼12.0 Hz,
CH ), 2.18 (s, 6H, aryl–CH ), 2.22 (s, 3H, aryl–CH ), 3.97
3 3 3
3
2
1
H, vinyl), 6.93 (s, 1H, aryl), 7.02 (d, J¼12.0 Hz, 1H, vinyl).
(q, J¼7.1 Hz, 2H, OCH ), 4.25 (q, J¼7.1 Hz, 2H, OCH ),
2
2
1
3
C NMR (75 MHz, CDCl ) d 13.89, 19.92, 21.25, 23.92,
3
6.20 (d, J¼15.9 Hz, 1H, vinyl), 7.26 (s, 1H, vinyl), 7.49
(d, J¼15.9 Hz, 1H, vinyl).
6
1
0.09, 123.27, 125.03, 129.29, 133.19, 134.36, 134.60,
36.94, 143.59, 165.19.
4.10.12. (2Z)-3-(2,4,6-Trimethylphenyl)propenoic acid
(6a). Colorless crystals. Mp 144–146 C (EtOH/hexane).
ꢁ
H NMR (300 MHz, CDCl ) d 2.15 (s, 6H, aryl–CH ),
4
propenoate (3f).
.10.6. Ethyl (2Z)-3-(3-hydroxy-2,4,6-trimethylphenyl)-
ꢁ
8
b,12
1
Colorless crystals. Mp 59–60 C (hex-
3
3
1
ane). H NMR (300 MHz, CDCl ) d 1.11 (t, J¼7.1 Hz, 3H,
2.27 (s, 3H, aryl–CH ), 6.10 (d, J¼12.0 Hz, 1H, vinyl),
3
3
CH ), 2.10 (s, 6H, aryl–CH ), 2.20 (s, 3H, aryl–CH ), 4.03
3
6.84 (s, 2H, aryl), 7.11 (d, J¼12.0 Hz, 1H, vinyl), 11.00 (s,
3
3
1
3
(
q, J¼7.1 Hz, 2H, OCH ), 4.49 (s, 1H, OH), 6.13 (d,
1H, COOH). C NMR (75 MHz, CDCl ): d 20.00, 20.89,
3
2
J¼12.0 Hz, 1H, vinyl), 6.80 (s, 1H, aryl), 7.00 (d,
122.07, 127.89, 131.99, 134.44, 136.92, 146.28, 171.10.
MS (EI, m/z) 190 (M ). Compound 6a was confirmed by
1
3
+
J¼12.0 Hz, 1H, vinyl).
C NMR (75 MHz, CDCl )
3
d 12.97, 13.96, 15.85, 19.54, 59.97, 120.18, 121.86,
1
converting it to its ethyl ester 3a using DMAP/DCC
method and comparing H and C NMR spectra. (2E)-
-(2,4,6-Trimethylphenyl)propenoic acid was observed in
3
0
1
13
22.86, 126.17, 129.15, 134.31, 143.94, 149.77, 165.39.
3
4
2
.10.7. Ethyl (2Z)-3-{3-[(1Z)-2-ethoxycarbonylethenyl]-
,4,6-trimethylphenyl}propenoate (4a).
the reaction of ethyl propiolate (2a) with mesitylene (1a)
at higher temperature and obtained as a mixture of Z- and
8
b,12
Light yellow