406 JOURNAL OF CHEMICAL RESEARCH 2009
(E, E)-2-Chloro-5-phenylpenta-2,4-dienoic
acid methyl ester
Table
esters
1
One-pot synthesis
of (E}-a-chloro-a,~-unsaturated
(3d): IR (CDCI3) 3018, 2990, 1734, 1215 em-I; IH NMR (CDCI3,
400 MHz) 1) 7.86 (dd,J= 11.7 Hz,J= 15.4 Hz, 1H), 7.54-7.49 (m,
2H, aromatic-H), 7.38-7.33 (m, 3H, aromatic-H), 7.03 (d,J= 11.0 Hz,
Entry
R
Product
Time/h
Yield/Yo" E:~
1H), 6.80 (d, J
= 15.4 Hz, 1H), 3.87 (s, 3H); l3C NMR (CDCI3,
2
87
10:1
3a
100 MHz) 1) 163.2, 142.6, 141.6, 136.1, 129.3, 128.7, 128.9, 128.8,
127.6,124.0,52.8; MS (EI) m/z (%) = 224 (10),222 (24) [M +],105
(100); HRMS (EI). Ca1cd for C12Hl10235CI(M + ) 222.0448. Found:
222.0445.
(E)-2-Chloro-nonenoic acid methyl ester (3e): IR (CDCI3) 3018,
2976, 1743, 1215 em-I; IH NMR (CDCI3, 400 MHz) 1) 6.44 (t,
0 -
CH,O
2
3b
3c
4
75
81
5:1
b-
3
2
11:1
J
= 7.4 Hz), 3.80 (s, 3H), 2.52 (q, J = 7.4 Hz, 2H), 1.42-1.40 (m,
0 -
0
2H), 1.31-1.25 (m, 6H), 0.86 (t, J= 6.6 Hz, 3H); l3C NMR (CDCI3,
100 MHz) 1) 163.2, 145.9, 121.5,52.7,31.6,30.1,29.1,28.9,22.6,
14.1; MS (EI) m/z (%) = 205 (6), 203 (14), [M-H], 113 (100); HRMS
(EI). Ca1cd for CIOH170235CI(M-H) 203.0838. Found: 203.0838.
4
3d
4
76
10:1
b
(E)-2-Chloro-5,9-dimethyldeca-2,8-dienoic
acid methyl ester (3f):
~
5
6
2
2
79
78
10:1
15:1
3e
3f
IR (CDCI3) 3018, 2956, 1718, 1217 em-I; IH NMR (CDCI3, 400
MHz) 1) 6.46 (t,J= 8.1 Hz, 1H), 5.07 (t, J= 7.3 Hz, 1H), 3.81 (s, 3H),
2.60-2.49 (m, 2H), 2.04-2.02 (m, 2H), 1.74 (s, 3H), 1.65 (s, 3H),
1.41-1.39 (m, 1H), 1.28-1.21 (m, 2H), 0.92 (d, J= 6.6 Hz, 3H); l3C
NMR (CDCI3, 100 MHz) 1) 163.2, 144.7, 131.5, 124.3, 122.1,52.6,
~
"Yields were based on aldehydes. bThis ratio was determined
by 1H NMR spectroscopy.
37.0,36.8,36.7,25.8,25.5,
243 (7) [M-H], 59 (100); HRMS (EI). Ca1cd for Cl3H2I02CI (M-H)
243.1153. Found: 243.1151.
19.5, 17.7; MS (EI) m/z (%) = 245 (2.5),
Conclusion
In conclusion, I have described a single flask procedure for
the stereoselective and efficient preparation of (E)-a-chloro-
a,13-unsaturated esters.
I thank the Research Centre, College of Science, King Saud
University for financial support; Project No. (Chem/2007/63).
My thanks to Professor H.M.R. Hoffmann for his revision of
the English.
Experimental
IR spectra were recorded on a Perkin Elmer 883 and spectrophotometer.
IH NMR and l3C NMR spectra were recorded using a JEOL ECP400
instrument in CDCI3. HRMS and NOE analysis were performed by
the Department of Organic Chemistry of the University of Hannover,
Germany.
Received 22 January 2009; accepted 23 April 2009
Published online: 13 July 2009
General procedure for the synthesis of (E)-a-chloro-a, 13-unsaturated
esters 3. A solution of2 (1.3 mmol) and 18-C-6 (1.3 mmol) in THF
(8 mL) was cooled to -78°C. Then (1.3 mmol) solid potassium
tert-butoxide was added to the solution. After stirring for 30 min at
-78°C, NCS (1.4 mmol) in THF (4 mL) and CH3CN (4 mL) was
added dropwise to the reaction mixture which was then stirred for
2 h at -78°C. Then 18-C-6 (1.3 mmol) and (1.3 mmol) potassium
tert-butoxide was added to the solution at the reaction mixture was
stirred for 30 min at -78°C. The aldehyde (I mmol) was the added
to the reaction mixture and stirring was continued. When the reaction
was complete, saturated aqueous NH4Cl was added to the solution
and the organic material was extracted with AcOEt. The combined
organic extracts were washed with H20 and brine, dried over Na2S04
and concentrated under reduced pressure. The residue was purified
by column chroatography on silica gel (petroleum ether: ethyl acetate
=20: I)
References
1
2
3
4
F. Bohlmann and R. Miethe, Chern. Ber., 1967,3861.
N. Hirayama, K.1. Shimizu, K. Shirata, K. Ueno and G. Tamura, Agric.
BioI. Chern., 1980,44,2083.
6
7
H. Cho, J.M. Beale, C. Graff, U. Mocek, A. Nakagawa, S. Omura and
M. Ojika, H. Niwa, Y. Shizuri and K. Yamada, J. Chern Soc., Chern.
Cornrnun., 1982, 628.
8
9
R. Grote,A. Zeeck, H. Drautz and H. Zahner, J. Antibiot., 1988,4, 1275.
G. Werner, H. Hagenmaier, H. Drautz, A. Baugartner and H. Zahner,
(E)-2-Chloro-3-phenylacrylic acid methyl ester (3a): IR (CDCI3)
3018,2995, 1734, 1215 em-I; IH NMR (CDCI3, 400 MHz) 1) 7.37-
7.28 (m, 6H, aromatic-H, vinylic-H), 3.74 (s, 3H); l3C NMR (CDCI3,
100 MHz) 1) 164.1, 137.5, 133.8, 129.1, 129.0, 128.4, 122.5, 52.9;
MS (EI) m/z (%) = 198(20), 196 (64) [M +],161 (100); HRMS (EI).
Ca1cd for ClOH90235CI(M +) 196.0291. Found: 196.0291.
10 S. Omura, N. Imamura, K. Hinitizawa, K. Otoguro, G. Lukacs, R. Faghih,
R. To1maan, B.H. Arison and J.L. Smith, J. Antibiot., 1983,36, 1782.
II L. Forti, F. Ghc1fi and U.M. Pagnomi, Tetrahedron Lett., 1995, 17, 3023.
13 D. Masure, R. Sauvetre. J.F. Normant and J. Villieras, Synthesis,
1976,761.
(E)-2-Chloro-3-(3-methoxyphenyl)acrylic
acid methyl ester (3b):
IR (CDCI3) 3018, 2958, 1751, 1215 em-I; IH NMR (CDCI3, 400
MHz) 1) 7.24-7.22 (m, 2H, aromatic-H), 7.16 (s, 1H), 6.89-6.85
(m, 2H, aromatic-H), 3.80 (s, 3H), 3.78 (s, 3H); l3C NMR (CDCI3,
100 MHz) 1) 162.9, 158.0, 141.7, 135.6, 128.1, 127.7, 121.1, 113.6,
14 M. A1ami, B. Crousse and G. Linstrumelle, Tetrahedron Lett., 1995,
363687.
112.4,53.9,51.6; MS (EI) m/z (%)
= 228 (20), 226 (56) [M +], 161
(100); HRMS (EI). Calcd for CllHl10335CI (M +) 226.0397. Found:
226.0397.
17 M.K. Tay, E. About-Jaude!, N. Collignon and P. Savignac, Tetrahedron,
(E)-2-Chloro-3-jUran-2-ylacrylic
(CDCI3) 3018, 2956, 1716, 1215 em-I; IH NMR (CDCI3, 400 MHz)
1) 7.46 (d, J 1.5 Hz, 1H), 7.24 (d, J 3.6 Hz, 1H), 7.08 (s, 1H),
6.47 (dd, J = 3.6, J = 1.5 Hz, 1H), 3.87 (s, 3H); l3C NMR (CDCI3,
100 MHz) 1) 163.4, 148.5, 144.5, 127.1, 118.3, 116.2, 112.7, 52.9;
MS (EI) m/z (%) = 188 (19), 186 (57) [M +],57 (100); HRMS (EI).
Ca1cd for C8H70335CI (M +) 186.0084. Found: 186.0084.
acid methyl ester (3c): IR
=
=