Design, synthesis, and insecticidal activities of novel monohalovinylated pyrethroids

Article abstract of DOI:10.1021/jf103908d

A series of novel monohalovinylated pyrethroids are designed and synthesized to replace one halo atom with a hydrogen atom on the double bond of dihalopyrethroids. Bioassays indicate that some of the synthesized compounds, such as 3j and 1j, exhibit high insecticidal activities against mosquitoes (Culex pipiens pallens), oriental armyworms (Mythimna separata), alfalfa aphids (Aphis medicagini), and carmine spider mites (Tetranychus cinnabarinus). Photolytic results of E-cis-1j suggest that monohalovinylated pyrethroids are photodegraded more easily than compound 12.

Full text of DOI:10.1021/jf103908d

ARTICLE
pubs.acs.org/JAFC
Design, Synthesis, and Insecticidal Activities of Novel
Monohalovinylated Pyrethroids
Zubiao Zheng,† Jing Wang,§ Deyan Zhang,† Xixia Guan,† Shuxu Gao,† Zizhan Chen,† and Xinzhuo Zou*,†
†Department of Chemistry, East China Normal University, Shanghai 200062, China
§School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China
ABSTRACT: A series of novel monohalovinylated pyrethroids are designed and synthesized to replace one halo atom with a
hydrogen atom on the double bond of dihalopyrethroids. Bioassays indicate that some of the synthesized compounds, such as 3j and
1j, exhibit high insecticidal activities against mosquitoes (Culex pipiens pallens), oriental armyworms (Mythimna separata), alfalfa
aphids (Aphis medicagini), and carmine spider mites (Tetranychus cinnabarinus). Photolytic results of E-cis-1j suggest that
monohalovinylated pyrethroids are photodegraded more easily than compound 12.
KEYWORDS: Pyrethroids, monohalovinylated pyrethroids, insecticide activities, photolysis
’ INTRODUCTION
light stability of monohalopyrethroids is slightly poorer than that
of the same structure bearing two halogen atoms, because it
deletes one halogen atom having electrophilicity and replaces it
with one hydrogen atom having electroneutrality on the double
bond. Monohalopyrethroids can be easily photodegraded or
biodegraded, thus solving the overstability problem of dihalo-
pyrethroids and generating high efficiency. However, there is a
need to improve the low insecticidal activity of this kind of py-
rethrate. R-Cyano-3-phenoxybenzyl-2,2-dimethyl-3-(2-halovinyl)cy-
clopropane carboxylate is detected in only minute quantities in
the biodegradation or photodegradation products of cyperme-
thrin and decamethrin and has never been efficiently used.9,10
Elliott synthesized R-cyano-3-phenoxybenzylmetahalo pyrethrate
and pointed out that its insecticidal activity was lower than that of its
corresponding R-cyano-3-phenoxybenzyl dihalopyrethrate.11 Jack
also reported some monohalopyrethroids containing fluorine.12 On
the basis of the above analysis and molecular design, we designed
and synthesized a series of monohalovinylated pyrethroids
(Scheme 1).
In recent years, problems brought about by the use of
agricultural chemicals have attracted considerable attention.1
Increases in population have caused increases in food require-
ments. These increases have been accompanied by climate
warming, pests, and diseases, many of which are transmitted by
mosquitoes. Infectious diseases, such as malaria and dengue
fever, are on the rise, posing grave threats to human health.2
Pesticide use has resulted in serious resistance problems, such
that increasing dosages are now necessary to eliminate the same
number of pests.
In response to these problems, the European Union (EU)
implemented a stringent set of standards in 2001 to ensure food
safety and testing. For example, the amount of fenvalerate in tea has
been limited to 0.05 mg/kg from 0.1 mg/kg, and many pesticides are
now limited to below 0.1 mg/kg.3 It is believed these standards will
eliminate the use of most pesticides. In their stead, the new standards
encourage the use of highly active, low-residue pesticides. Current
pesticide research and agricultural and pesticide production are now
faced with the serious challenge of reducing pesticide use in the EU
to adapt to new requirements.
’ MATERIALS AND METHODS
Pyrethroids are a kind of biomimetic pesticide with excellent
properties, such as high activity, a wide insecticidal spectrum, and
low toxicity to humans and other mammals.4 Research in the field
of pyrethroids has generated great excitement in the past several
decades.5 This type of pesticide, however, has two limitations:
resistance buildup and high residue formation. As a major
product of pyrethroids, cypermethrin has come to be suspected
as an endocrine-disrupting compound and is listed in the Our
Stolen Future Web site.6 As well, decamethrin is believed to have
mutagenic and teratogenic effects.7,8
Careful analysis of the chemical structures of pyrethroids has
indicated that dihalopyrethroids, represented by cypermethrin
and decamethrin, have high efficiency and low toxicity. It is
possible that the poor light stability of the double bonds in these
compounds causes the occurrence of overstability phenomena.
Thus, with increasing residual time in the environment, terato-
genicity, mutagenicity, and endocrine disruption may result. The
Instruments. Melting points (mp) were recorded on a Yanano MP
500 apparatus and are uncorrected. 1H NMR spectra were recorded on a
Varian INOVA-500 (500 MHz) spectrometer with CDCl3 as the solvent
and TMS as the internal standard. IR spectra were recorded on a Nicolet
FT-IR spectrometer. High-resolution mass spectra were recorded under
electron impact (70 eV) conditions using a MicroMass GCT CA 055
instrument. GC-MS data were obtained on an Agilent 6890/5973N
instrument. Analytical thin-layer chromatography (TLC) was carried
out on precoated plates (silica gel 60 F254), and spots were visualized
with ultraviolet (UV) light. Ultraviolet irradiation was carried out at 365
nm with two lamps (15 W) in an ultraviolet analyzer (Shanghai Keyi
Optical Instrument Factory).
Received: October 7, 2010
Accepted: December 28, 2010
Revised:
December 24, 2010
Published: January 28, 2011
r
2011 American Chemical Society
1171
dx.doi.org/10.1021/jf103908d J. Agric. Food Chem. 2011, 59, 1171–1177
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Journal of Agricultural and Food Chemistry
ARTICLE
Scheme 1. General Synthetic Procedure for the Target
Compounds
General Synthetic Procedure for 8-11. A mixture of sodium
hydroxide (125 mmol), water (15 mL), methanol (50 mL), 86 mmol of
methyl 3-(2-halovinyl)-2,2-dimethylcyclopropanecarboxylate (6 or 7),
and tetrabutylammonium bromide (1 g) was stirred for 5 h at reflux, after
which the solvent was removed in vacuo. The residue was dissolved in 30
mL of water, and CO2 gas was passed into the system continuously at
room temperature for 4 h. The mixture was extracted with diethyl ether
(50 mL ꢀ 3). The combined extracts were washed with saturated brine
and dried with anhydrous magnesium, and the solvent was removed in
vacuo to obtain a sticky brown product (cis-8 or cis-9). The residual
water layer was acidified with 10% HCl and purified to obtain the trans-
isomers as yellow liquid (trans-10 or trans-11).
Data for 8:. recrystallized in hexane to give a white solid; mp 84-94 °C;
1
E-cis/Z-cis = 6:4; H NMR (500 MHz, CDCl3) δ 1.20 (s, 0.4 ꢀ 6H,
cyclo-CH3), 1.27 (s, 0.6ꢀ6H, cyclo-CH3), 1.73 (d, 0.6ꢀ1H, J = 8.0 Hz,
cyclo-CH), 1.82 (d, 0.4 ꢀ 1H, J = 8.0 Hz, cyclo-CH), 1.90 (dd, 0.6 ꢀ 1H,
J1 = 8.0 Hz, J2 =10.0 Hz, cyclo-CH), 2.32 (dd, 0.4 ꢀ 1H, J1 = 8.0 Hz, J2 =
8.5 Hz, cyclo-CH), 6.08 (d, 0.6ꢀ1H, J = 13.0 Hz, (E)ClHCd), 6.10 (dd,
0.4 ꢀ 1H, J1 = 8.5 Hz, J2 =7.5 Hz, (Z)HCd), 6.15 (d, 0.4 ꢀ 1H, J = 7.5 Hz,
(Z)ClHCd), 6.22 (dd, 0.6ꢀ1H, J1 =10.0 Hz, J2 = 13.0 Hz, (E)CHd),
11.97 (s, 1H, COOH); IR (KBr, cm-1) 2964, 1692, 1225, 937.
1
Data for 9:. yellow liquid; E-cis/Z-cis = 6:4; H NMR (500 MHz,
CDCl3) δ 1.22 (s, 0.4 ꢀ 6H, cyclo-CH3), 1.29, 1.31 (2s, 0.6ꢀ6H, cyclo-
CH3), 1.75 (d, 0.6 ꢀ 1H, J = 8.0 Hz, cyclo-CH), 1.85 (d, 0.4 ꢀ1H, J = 9.0
Hz, cyclo-CH), 1.91 (dd, 0.6 ꢀ 1H, J1 = J2 = 9.0 Hz, cyclo-CH),
2.23-2.28 (dd, 0.4 ꢀ 1H, J1 = 9.0 Hz, J2 = 7.0 Hz, cyclo-CH), 6.17
(d, 0.6 ꢀ 1H, J = 13.0 Hz, (E)BrHCd), 6.30 (d, 0.4 ꢀ 1H, J = 7.0 Hz,
(Z)BrHCd), 6.45 (dd, 0.4 ꢀ 1H, J1 = J2 = 7.0 Hz, (Z)CHd), 6.49 (dd,
0.6 ꢀ 1H, J1 = 9.0 Hz, J2 = 13.0 Hz, (E)CHd), 11.59 (s, 1H, -COOH);
IR (KBr, cm-1) 1703, 1215, 938.
1
Data for 10:. yellow liquid; E-trans/Z-trans = 7:3; H NMR (500
MHz, CDCl3) δ 1.21, 1.28 (2s, 2ꢀ3H, cyclo-CH3), 1.60-1.62 (m, 0.7 ꢀ
1H, cyclo-CH), 1.74 (d, 0.3ꢀ1H, J = 5.0 Hz, cyclo-CH), 2.07-2.10 (m,
0.7 ꢀ 1H, cyclo-CH), 2.44-2.46 (m, 0.3ꢀ 1H, cyclo-CH), 5.46 (dd,
0.3 ꢀ 1H, J1 = J2 = 7.0 Hz, (Z)CHd), 5.66-5.08 (dd, 0.7 ꢀ 1H, J1 = J2 =
13.0 Hz, (E)CHd), 6.08-6.11 (d, 0.7ꢀ1H, J = 13.0 Hz, (E)ClHCd),
6.15-6.16 (d, 0.3ꢀ1H, J=7.0 Hz, (Z)ClHCd), 11.68 (s, 1H, -COOH);
IR (KBr, cm-1) 2966, 1690, 1220, 935.
Synthetic Procedures. All anhydrous solvents were dried and
purified according to standard techniques just before use. Methyl 2,2-
dimethyl-3-formylcyclopropanecarboxylate,13 2- and 3-fluoro-
4-(methoxymethyl)benzyl alcohol,14 2- and 3-fluoro-4-methylbenzyl
alcohol,15 2,3,5,6-tetrafluoro-4-methylbenzyl alcohol, 2,3,5,6-tetra-
fluoro-4-(methoxymethyl)benzyl alcohol, 2,3,5,6-tetrafluorobenzyl al-
cohol, and 2,3,4,5,6-pentafluorobenzyl alcohol were synthesized
according to literature methods.16 4-Hepten-1-yn-3-ol, 2-cyclopenten-
1-one, and 3-phenoxybenzaldehyde were provided by Zhongxi Yaoye
Corp. Unless otherwise noted, reagents and solvents were used as
received from commercial suppliers.
Data for 11:. yellow liquid; E-trans-isomer/Z-trans-isomer = 6:4; 1H
NMR (500 MHz, CDCl3) δ 1.21 (s, 0.6ꢀ3H, cyclo-CH3), 1.26 (s, 0.4ꢀ
3H, cyclo-CH3), 1.29 (s, 0.6 ꢀ 3H, cyclo-CH3), 1.36 (s, 0.4ꢀ3H, cyclo-
CH3), 1.60-1.63 (d, 0.6 ꢀ 1H, J = 4.0 Hz, cyclo-H), 1.98 (d, 0.4ꢀ1H, J =
4.0 Hz, cyclo-H), 2.08-2.10 (m, 0.6 ꢀ 1H, cyclo-H), 2.38-2.41 (m, 0.4 ꢀ
1H, cyclo-H), 5.86-5.89 (dd, 0.4 ꢀ 1H, J1 = J2 = 7.0 Hz, (Z)CHd),
5.92-5.97 (dd, 0.6 ꢀ 1H, J1 = J2 = 14.0 Hz, (E)CHd), 6.19(d, 0.6 ꢀ 1H,
J = 14.0 Hz, (E)BrHCd), 6.31 (d, 0.4 ꢀ 1H, J = 7.0 Hz, (Z)BrHCd),
10.5(b, 1H, COOH); IR (KBr, cm-1) 1703, 1215, 938.
General Synthetic Procedure for 6 and 7. Ph3PþCH2Cl Cl-
(2.1 mmol) or Ph3PþCH2Br Br- was added to a round-bottom flask,
which was then flushed with nitrogen. Anhydrous ether (20 mL) and
piperidine (2.1 mmol) were added to the flask, and the mixture was
cooled to -60 to -70 °C by liquid nitrogen. About 9.5 mL of 2.2 mol/L
(2.1 mmol) of n-BuLi was added to the mixture, which was then allowed
to react for 1.5 h. Then, 2.1 mmol of methyl 2, 2-dimethyl-3-formylcy-
clopropanecarboxylate in 10 mL of benzene was added, and the mixture
was stirred for 3 days and 20 min at room temperature. The reaction
liquid was washed with 10% of H2SO4 solution in brine and dried. The
solvent was removed under reduced pressure, and the crude product was
purified by column chromatography to give a colorless liquid.
Data for 6:. yield, 58%; 1H NMR (500 MHz, CDCl3) δ 1.18, 1.20
(2s, 3H, cyclo-CH3), 1.25, 1.28 (2s, 3H, cyclo-CH3), 1.56-1.58 (m, 1H,
cyclo-H), 2.04-2.05 (m, 1H, cyclo-H), 3.68, 3.69 (2s, 3H, COOCH3),
5.47-5.70 (m, 1H, dCH), 6.06-6.14 (m, 1H, dCHCl); IR (KBr,
cm-1) 1725, 1409, 1150.
General Synthetic Procedure for 1a-c, 1f, 1h-j, 2a-c,
3c-j, and 4d, and 4e. A mixture of monohalovinylated acid (5.7
mmol) and thionyl chloride (5.0 mL) was heated to 50 °C for 4-5 h.
The excess thionyl chloride was removed in vacuo, and the residue was
diluted with benzene (5.0 mL) for use. To a solution of alcohol (5.7
mmol) and pyridine (0.8 mL) in benzene (10 mL) was slowly added the
acyl chloride solution prepared abovein an ice-water bath for 30 min.
The mixture was stirred overnight, and then 10 mL of water was added.
The organic phase was separated and washed successively with 10 mL of
5% NaOH solution, 5% of hydrochloric acid solution and brine, and
dried with Na2SO4. The solvent was removed to give a yellow and
viscous product. The crude product was purified by column chroma-
tography (petroleum ether/ethyl acetate = 20:1) to afford a light yellow
liquid.
Data for 7:. yield, 40%; 1H NMR (500 MHz, CDCl3) δ 1.19, 1.21
(2s, 3H, cyclo-CH3), 1.25, 1.29 (2s, 3H, cyclo-CH3), 1.62-1.65 (m, 1H,
cyclo-H), 2.05-2.20 (m, 1H, cyclo-H), 3.69, 3.70 (2s, 3H, COOCH3),
5.85-5.97 (m, 1H, dCH), 6.16-6.30 (m, 1H, dCHBr); IR (KBr,
cm-1) 1728, 1407, 1173.
Data for 1a:. yield, 72%; 1H NMR (500 MHz, CDCl3) δ 0.98 (t, 3H,
J1 =J2 = 8.0 Hz, CH3), 1.18 (s, 3H, cyclo-CH3), 1.26, 1.29 (2s, 3H, cyclo-
CH3), 1.73 (s, 3H, dCH3), 1.77 (d, 1H, J = 9.0 Hz, cyclo-CH),
1172
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Journal of Agricultural and Food Chemistry
ARTICLE
1.81-1.86 (m, 1H, cyclo-CH), 2.05-2.08 (m, 2H, -CH2-), 2.52 (s,
1H, CHt), 5.69 (dd, 1H, J1 = J2 = 7.0 Hz, dCH—Et), 5.74, 5.76 (2s,
1H, COOCH), 6.05 (dd, 1H, J1 = 4.5 Hz, J2 = 13.5 Hz, ClHCd),
6.22-6.29 (m, 1H, CHd); IR (KBr, cm-1) 3298, 2963, 2932, 2875,
1729, 1409, 1365, 1175, 1132, 1079; HRMS calcd for C16H21O235Cl
(Mþ), 280.1231; found, 280.1236.
(Z)CHd), 6.40-6.52 (m, 1H, BrHCd); IR (KBr, cm-1) 1714, 1656,
1384, 1156; HRMS calcd for C17H23O379Br (Mþ), 354.0831; found,
354.0835.
Data for 2c:. yield, 85%; 1H NMR (500 MHz, CDCl3) δ 1.12-1.25
(m, 6H, cyclo-CH3), 1.74 (d, 0.6 ꢀ 1H, J = 8.0 Hz, cyclo-CH),
1.82-1.91 (m, 1H, cyclo-CH), 2.24 (m, 0.4 ꢀ 1H, cyclo-CH), 6.09
(d, 0.4 ꢀ 1H, J = 13.0 Hz, (Z)BrCHd), 6.14 (d, 0.6 ꢀ 1H, J = 8.0 Hz,
(E)BrCHd), 6.26, 6.32 (2s, 1H, CH—CN), 6.36-6.99 (m, 1H, CHd),
6.95-6.99 (m, 3H, ArH), 7.07-7.10 (m, 2H, ArH), 7.15-7.18 (m, 1H,
ArH), 7.28-7.34 (m, 3H, ArH); IR (KBr, cm-1) 3064, 2961, 1745,
1586, 1478, 1448, 1246, 1109, 693; HRMS calcd for C22H20NO379Br
(Mþ), 425.0627; found, 425.0621.
Data for 1b:. yield, 76%; 1H NMR (500 MHz, CDCl3) δ 1.14, 1.20,
1.21, 1.22 (4s, 6H, cyclo-CH3), 1.69 (d, 0.6H, J = 8.0 Hz, cyclo-CH),
1.79-1.82 (m, 1H, cyclo-CH), 1.94 (2s, 3H, dCH3), 2.17-2.23 (m,
1.4H, cyclo-CH, COCH2), 2.73-2.81 (m, 1H, COCH2), 2.91 (d, 2H,
J = 6.0 Hz, dCH2), 4.93-4.96 (m, 2H, dCH2), 5.59-5.73 (m, 2H,
COOCH, CH2dCH), 5.99-6.21 (m, 2H, HCldCH); IR (KBr, cm-1
)
1715, 1655, 1413, 1170, 1132, 1081; HRMS calcd for C17H23O335Cl
(Mþ), 310.1337; found, 310.1335.
Data for 3c:. yield, 85%; 1H NMR (500 MHz, CDCl3) δ 1.19, 1.20,
1.27, 1.30 (4s, 6H, cyclo-CH3), 1.66-1.68 (m, 1H, cyclo-CH),
2.12-2.17 (m, 1H, cyclo-CH), 5.51-5.72 (m, 1H, CHd), 6.09-6.22
(m, 1H, ClHCd), 6.38, 6.43 (2s, 1H, CH—CN), 7.03-7.07 (m, 3H,
ArH), 7.13-7.18 (m, 2H, ArH), 7.24-7.26 (m, 1H, ArH), 7.36-7.42
(m, 3H, ArH); IR (KBr, cm-1) 3439, 2948, 1725, 1570, 1207, 1069;
HRMS calcd for C22H20NO335Cl (Mþ), 381.1133; found, 381.1136.
Data for 3d:. yield, 57%; 1H NMR (500 MHz,CDCl3) δ 1.16, 1.18,
1.24, 1.26 (4s, 6H, cyclo-CH3), 1.60-1.63 (m, 0.7 ꢀ 1H, cyclo-H),
1.78-1.90 (m, 0.7 ꢀ 1H, cyclo-CH), 1.96 (m, 0.3 ꢀ 1H, cyclo-CH),
2.07 (m, 0.3 ꢀ 1H, cyclo-CH), 2.27 (s, 0.7 ꢀ 3H, Ar—CH3), 2.35 (s, 0.3
ꢀ 3H, Ar—CH3), 5.05-5.08 (m, 0.7 ꢀ 2H, COOCH2), 5.13-5.17 (m,
0.3 ꢀ 2H, COOCH2), 5.50 (dd, 0.3 ꢀ 1H, J1 = 8 Hz, J2 = 7.0 Hz,
(Z)CHd), 5.64-5.69 (m, 0.7 ꢀ 1H, (E)CHd), 6.08 (dd, 0.7 ꢀ 1H,
J1 = J2= 13.0 Hz, (E)ClHCd), 6.14 (d, 0.3 ꢀ 1H, J = 7.0 Hz, (Z)ClHCd),
6.89-6.95 (m, 1H, ArH), 6.98-7.04 (m, 1H, ArH), 7.15-7.26 (m, 1H,
ArH); IR (KBr, cm-1) 1726, 1631, 1473, 1401, 1384, 1115,982; HRMS
calcd for C16H18O235ClF (Mþ), 296.0980; found, 296.0988.
Data for 1c:. yield, 85%; 1H NMR (500 MHz, CDCl3) δ 1.20,1.22
(2s, 0.4 ꢀ 6H, cyclo-CH3), 1.25,1.32 (2s, 0.6ꢀ6H, cyclo-CH3), 1.81 (dd,
1H, J1 = J2 = 8.0 Hz, cyclo-CH), 1.91-1.98 (m, 1H, cyclo-CH), 6.11
(dd, 1H, J1 = 7.0 Hz, J2 = 13.0 Hz, ClHCd), 6.18-6.23 (m, 1H, dCH),
6.34 (s, 0.6ꢀ1H, CH—CN), 6.40 (s, 0.4 ꢀ 1H, CH—CN), 7.03-7.07
(m, 3H, ArH), 7.15-7.18 (m, 2H, ArH), 7.23-7.26 (m, 1H, ArH),
7.37-7.42 (m, 3H, ArH); IR (KBr, cm-1) 3446, 3071, 2959, 1741,
1588, 1487, 1244, 1122, 1073; HRMS calcd for C22H20NO335Cl (Mþ),
381.1133; found, 381.1131.
Data for 1i:. yield, 85%; 1H NMR (500 MHz, CDCl3) δ 1.19-1.28
(4s, 6H, cyclo-CH3), 1.69,1.71 (2d, 1H, J1 =J2 = 8.0 Hz, cyclo-CH), 1.84
(m, 1H, cyclo-CH), 5.15-5.25 (m, 2H, COOCH2), 5.92 (d, 0.4 ꢀ 1H,
J = 8.0 Hz, (Z)ClHCd), 6.06 (d, 0.6 ꢀ 1H, J =14.0 Hz, (E)ClHCd),
6.23 (m, 1H, HCd); IR (KBr, cm-1) 3031, 2961, 1725, 1611; HRMS
calcd for C15H12O235ClF5 (Mþ), 354.0446; found, 354.0449.
Data for 1h:. yield, 63%; 1H NMR (500 MHz, CDCl3) δ 1.21-1.29
(4s, 6H, cyclo-CH3), 1.77 (dd, 1H, J1 =J2 =9.0 Hz, cyclo-CH), 1.84-1.91
(m, 1H, cyclo-CH), 5.09-5.15 (q, 2H, J = 3.0 Hz, COOCH2), 5.93 (d,
0.4 ꢀ 1H, J = 8.0 Hz, (Z)ClHCd), 6.06 (d, 0.6 ꢀ 1H, J = 13.0 Hz,
(E)ClHCd), 6.21-6.25 (m, 1H, HCd), 7.02-7.07 (m, 1H, ArH); IR
(KBr, cm-1) 3001, 2801, 1730, 1633; HRMS calcd for C15H13O235ClF4
(Mþ), 336.0541; found, 336.0547.
Data for 3e:. yield, 53%; 1H NMR (500 MHz,CDCl3) δ 1.23 (s, 3H,
cyclo-CH3), 1.30, 1.33 (2s, 3H, cyclo-CH3), 1.81-1.85 (m, 1H, cyclo-
CH), 1.90-1.96 (m, 1H, cyclo-CH), 3.45, 3.46 (2s, 3H, OCH3), 4.50,
4.57 (2s, 2H, ArCH2), 5.12-5.21 (m, 2H, COOCH2), 5.67-5.73 (m,
0.3 ꢀ 1H, (Z)CHd), 6.12 (d, 0.7 ꢀ 1H, J = 13.0 Hz, (E)ClCHd), 6.19
(d, 0.3 ꢀ 1H, J = 7.0 Hz, (Z)ClHCd), 6.32 (dd, 0.7 ꢀ 1H, J1 = J2 = 13.0
Hz, (E)HCd), 7.10-7.18 (m, 2H, ArH), 7.39-7.46 (m, 1H, ArH); IR
(KBr, cm-1) 1726, 1631, 1401, 1384, 1100, 1003, 980; HRMS calcd for
C17H20O335ClF (Mþ), 326.1086; found, 326.1082.
Data for 1f:. yield, 75%; 1H NMR (500 MHz,CDCl3) δ 1.19-1.28
(4s, 6H, cyclo-CH3), 1.70 (dd, 1H, J1 =J2 = 9 Hz, cyclo-CH), 1.83 (m,
1H, cyclo-CH), 2.28-2.29 (m, 3H, ArCH3), 5.15 (q, 2H, J = 3.0 Hz,
COOCH2), 6.05 (dd, 1H, J1 = 13.0 Hz, J2 = 8.0 Hz, ClHCd), 6.21 (m,
1H, HCd); IR (KBr, cm-1) 2934, 2876, 1720, 1601; HRMS calcd for
C16H15O235ClF4 (Mþ), 350.0697; found, 350.0703.
Data for 3f:. yield, 75%; 1H NMR (500 MHz,CDCl3) δ 1.16 (s, 3H,
cyclo-CH3), 1.24 (s, 3H, cyclo-CH3), 1.55 (d, 1H, J = 6.0 Hz, cyclo-CH),
2.05-2.08 (m, 0.7 ꢀ 1H, cyclo-CH), 2.29 (s, 3H, ArCH3), 2.41-2.43 (m,
0.3 ꢀ 1H, cyclo-CH), 5.16-5.19 (m, 2H, COOCH2), 5.47 (t, 0.3 ꢀ 1H,
J = 8.0 Hz, (Z)CHd), 5.66 (dd, 0.7 ꢀ 1H, J1 = J2 = 13.0 Hz, (E)CHd),
6.06 (d, 0.7 ꢀ 1H, J = 13.0 Hz, (E)ClHCd), 6.14 (d, 0.3 ꢀ 1H, J = 8.0 Hz,
(Z)ClHCd); IR (KBr, cm-1) 3010, 2716, 1740, 1636, 1384; HRMS calcd
for C16H15O235ClF4 (Mþ), 350.0697; found, 350.0701.
Data for 1j:. yield, 82%; 1H NMR (500 MHz CDCl3) δ 1.16, 1.18
(2s, 0.4 ꢀ 6H, cyclo-CH3), 1.21, 1.28 (2s, 0.6ꢀ6H, cyclo-CH3), 1.77 (m,
1H, cyclo-CH), 1.89-1.90 (m, 1H, cyclo-CH), 6.06 (m, 1H, ClHCd),
6.14-6.20 (m, 1H, dCH), 6.27-6.32 (2s, 1H, CH—CN), 6.98-6.99 (m,
2H, ArH), 7.11-7.14 (m, 1H, ArH), 7.19-7.27 (m, 3H, ArH), 7.32-7.35
(m, 2H, ArH); IR (KBr, cm-1) 1728, 1587, 1487, 1241, 1122, 998; HRMS
calcd for C22H19NO335ClF (Mþ), 399.1037; found, 399.1035.
Data for 3g:. yield, 84%; 1H NMR (500 MHz, CDCl3) δ 1.17 (s, 3H,
cyclo-CH3), 1.25 (s, 3H, cyclo-CH3), 1.58 (d, 1H, J = 5.5 Hz, cyclo-CH),
2.07 (dd, 0.7 ꢀ 1H, J1 = 5.5 Hz, J2 = 9.0 Hz, cyclo-CH), 2.41 (dd, 0.3 ꢀ
1H, J1 = 5.5 Hz, J2 = 8.5 Hz, cyclo-CH), 3.40 (s, 0.7 ꢀ 3H, OCH3), 3.42
(s, 0.3 ꢀ 3H, OCH3), 4.52 (s, 0.3 ꢀ 2H, ArCH2), 4.58 (s, 0.7 ꢀ 2H,
ArCH2), 5.19-5.26 (m, 2H, COOCH2), 5.45 (t, 0.3ꢀ1H, J = 8.0 Hz,
(Z)CHd), 5.65 (dd, 0.7 ꢀ 1H, J1 = 13.0 Hz, J2 = 9.0 Hz, (E)CHd), 6.08
(d, 0.7 ꢀ 1H, J = 13.0 Hz, (E)ClHCd), 6.16 (d, 0.3ꢀ1H, J = 8.0 Hz, (Z)
ClHCd); IR (KBr, cm-1) 2933, 2862, 1722, 1603; HRMS calcd for
C17H17O335ClF4 (Mþ), 380.0803; found, 380.0809.
Data for 2a:. yield, 73%; 1H NMR (500 MHz, CDCl3) δ 0.97-1.00
(m, 3H, CH3), 1.24, 1.27, 1.30 (3s, 6H, cyclo-CH3), 1.74 (d, 3H, J =
4.0 Hz, dCH3), 1.87 (d, 1H, J = 9.0 Hz, cyclo-CH), 2.04-2.11 (m, 2H,
-CH2-), 2.20 (m, 1H, cyclo-CH), 2.51-2.52 (m, 1H, tCH), 5.70 (m,
1H, dCH2—Et), 5.74, 5.76 (2s, 1H, COOCH), 6.28 (dd, 1H, J1=6 Hz,
J2=12 Hz, BrHCd), 6.47-6.51 (m, 1H, CHd); IR (KBr, cm-1) 3296,
2965, 2869, 1728, 1407, 1173, 1131. HRMS calcd for C16H21O279Br
(Mþ), 324.0725; found, 324.0729.
Data for 2b:. yield, 77%; 1H NMR (500 MHz, CDCl3) δ 1.18-1.28
(m, 2 ꢀ 3H, cyclo-CH3), 1.74-1.76 (m, 0.6 ꢀ 1H, cyclo-CH),
1.83-1.88 (m, 1H, cyclo-CH), 2.00(s, 3H, dCH3), 2.18-2.27 (m,
1.4 ꢀ 1H, cyclo-CH, COCH2), 2.79-2.87 (m, 1H, COCH2), 2.97 (d,
2H, J = 7.0 Hz, dCH2), 4.99 (d, 1H, J = 10.0 Hz, dCH2), 5.00 (d, 1H,
J = 18.0 Hz, dCH2), 5.64-5.79 (m, 2H, COOCH, —CHd), 6.15 (dd,
0.6 ꢀ 1H, J1 = J2 = 13.0 Hz, (E)CHd), 6.28-6.30 (m, 0.4 ꢀ 1H,
Data for 3h:. yield, 70%; 1H NMR (500 MHz, CDCl3) δ 1.17, 1.23
(2s, 3H, cyclo-CH3), 1.25, 1.32 (2s, 3H, cyclo-CH3), 1.61 (d, 1H, J = 5.0
Hz, cyclo-CH), 2.07-2.09 (m, 0.7ꢀ1H, cyclo-CH), 2.41-2.43 (m, 0.3ꢀ
1H, cyclo-CH), 5.13-5.15 (m, 2H, COOCH2), 5.49 (t, 0.3 ꢀ 1H, J =
8.0 Hz, (Z)CHd), 5.65 (dd, 0.7 ꢀ 1H, J1 = J2 = 14.0 Hz, (E)CHd), 6.08
(d, 0.7 ꢀ 1H, J = 14.0 Hz, (E) ClHCd), 6.16 (d, 0.3 ꢀ 1H, J = 8.0 Hz,
(Z) ClHCd), 7.02-7.07 (m, 1H, ArH); IR (KBr, cm-1) 2929, 2828, 17
1173
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Journal of Agricultural and Food Chemistry
ARTICLE
Table 1. Insecticidal Activities of the Title Compounds, Deltamethrin, and Cypermethrin against Mosquitoes (Culex pipiens
pallens)a
LC50(mg/L)
LC95(mg/L)
LC50(mg/L)
LC95(mg/L)
compd
(95% fiducial limit)
(95% fiducial limit)
toxic ratiob
3.2
compd
(95% fiducial limit)
(95% fiducial limit)
toxic ratio
1.8
1a
0.3290
(0.2926-0.3698)
0.3899
1.0957
(0.9599-1.2779)
0.7164
3d
3e
3f
0.6049 (0.5791-0.6319)
0.9465 (0.8945-1.0223)
1b
1c
1f
2.7
220.8
14.3
13.2
2.2
0.7495
(0.7103-0.7909)
0.0578
1.3021
(1.1452-1.8139)
0.0900
1.4
18
(0.3675-0.4137)
0.0048
(0.6209-0.8782)
0.0127
(0.0043-0.0052)
0.0741
(0.0114-0.0147)
0.1354
(0.0553-0.0603)
0.2025
(0.0804-0.1186)
0.4461
3g
3h
3i
5.2
(0.0699-0.0786)
0.0801
(0.1200-0.2128)
0.1476
(0.1876-0.2187)
0.2492
(.3471-3.7111)
0.3580
1i
4.3
(0.0756-0.0850)
0.4810
(0.1360-0.1555)
0.7262
(0.2394-0.2594)
0.2041
(0.3378-0.6238)
0.2639
1h
1j
5.2
(0.4621-0.5006)
0.00047
(0.6197-1.1865)
0.00168
(0.1991-0.2093)
0.0055
(0.2553-0.2762)
0.0861
2255.3
3.8
3j
192.7
5.0
(0.00042-0.00054)
0.2809
(0.00076-0.00326)
0.4033
(0.0042-0.0072)
0.2133
(0.0746-0.0991)
0.4405
2a
2b
2c
3c
4d
4e
(0.2711-0.2909)
0.4403
(0.3866-0.4296)
0.7054
(0.1987-0.2289)
0.2776
(0.3641-0.7863)
0.5681
2.4
3.8
(0.4206-0.4610)
0.0108
(0.6272-0.9126)
0.0221
(0.2589-0.2976)
0.0012
(0.4563-0.9448)
0.0033
98
deltamethrin
cyperethrin
883
100
(0.0101-0.0116)
0.0527
(0.0198-0.0393)
0.1268
(0.0008-0.0018)
0.0106
(0.0031-0.0035)
0.0286
20
(0.0484-0.0574)
(0.0874-0.5697)
(0.0094-0.0119)
(0.0232-0.0354)
a The insecticidal activity report was provided by Shanghai Manyi Science and Technology Co. Ltd. b Toxic ratio is defined as the ratio of
cypermethrin’s LC50 value for baseline toxicity and the compounds’ LC50 values.
27, 1619; HRMS calcd for C15H13O235ClF4 (Mþ), 336.0541; found,
336.0544.
cyclo-H), 3.40, 3.41 (2s, 3H, OCH3), 4.45, 4.52 (s, 2H, ArCH2),
5.08-5.17 (m, 2H, COOCH2), 5.87 (t, 0.4 ꢀ 1H, J = 8.0 Hz, (Z)CHd),
5.90-5.96 (m, 0.6 ꢀ 1H, (E)CHd), 6.15-6.19 (dd, 0.6 ꢀ 1H, J1 =J2 =
14.0 Hz, (E)BrHCd), 6.29 (d, 0.4 ꢀ 1H, J = 7.0 Hz, (Z)BrHCd),
7.05-7.15 (m, 2H, ArH), 7.34-7.42 (m, 1H, ArH); IR (KBr, cm-1) 1728,
1636, 1400, 1384, 1158, 1114, 1002; HRMS calcd for C17H20O379BrF (Mþ),
370.0580; found, 370.0585.
Biological Assay. Bioassays were conducted with four insect
species, mosquito (Culex pipiens pallens) (Shanghai Manyi Science
and Technology Co. Ltd.), armyworm (Mythimna separata), aphid
(Aphis craccivora), and carmine spider mites (Tetranychus cinnabarinus)
(Shanghai Southern Pesticides Research Center, China). All bioassays
were performed on representative test organisms reared in the labora-
tory. The bioassay was repeated at 26 ( 1 °C and 70 ( 10% relative
humidity according to statistical requirements. All compounds were
dissolved in acetone and diluted with water to obtain series concentra-
tions for bioassays. Each concentration was tested three times in parallel.
Concentrations of 500.0, 50.0, and 5.0 mg L-1 and others for mosqui-
toes, 500.0, 50.0, 5.0,1.0, 0.5, and 0.25 mg L-1 for armyworms and
aphids, and 500.0, 50.0, 5.0, and 1.0 mg L-1 for spider mites were used.
For comparative purposes, cypermethrin and decamethrin were tested
under the same conditions.
Insecticidal Test for Mosquito. The activities of insecticidal com-
pounds against mosquito were tested by the dipping method according
to the reported procedure.17,18 Twenty-five fourth-instar mosquito
larvae (wrigglers) were put into appropriate solutions of the tested
compounds, and the mortality rates were evaluated 24 h after treatment.
Insecticidal Test for Armyworm. The activities of insecticidal com-
pounds 3f, 3j, and 1j against armyworms were evaluated by foliar
application using the reported procedure.19,20 For the foliar armyworm
tests, individual corn leaves were placed on moistened pieces of filter
Data for 3i:. yield, 71%; 1H NMR (500 MHz, CDCl3) δ1.17, 1.24 (2s,
3H, cyclo-CH3), 1.25, 1.31 (2s, 3H, cyclo-CH3), 1.58 (d, 0.7 ꢀ 1H, J = 5.0
Hz, cyclo-CH), 2.06-2.09 (m, 0.7 ꢀ 1H, cyclo-CH), 2.41-2.43 (m, 0.3 ꢀ
1H, cyclo-CH), 5.17-5.19 (m, 2H, COOCH2), 5.48 (t, 0.3 ꢀ 1H, J=7Hz,
(Z)CHd), 5.64 (dd, 0.7 ꢀ 1H, J1 = J2 = 13.0 Hz, (E)CHd), 6.07 (d, 0.7 ꢀ
1H, J = 13.0 Hz, (E)ClHCd), 6.15 (d, 0.3 ꢀ 1H, J = 8.0 Hz, (Z)ClHCd);
IR (KBr, cm-1) 3128, 2962, 1736, 1656, 970; HRMS calcd for
C15H12O235ClF5 (Mþ), 354.0446; found, 354.0442.
Data for 3j:. yield, 80%; 1H NMR (500 MHz, CDCl3) δ 1.18-1.29
(m, 6H, cyclo-CH3), 1.61-1.64 (m, 1H, cyclo-CH), 2.12-2.15 (m, 1H,
cyclo-CH), 5.64-5.70 (m, 1H, CHd), 6.12 (m, 1H, HClCd), 6.31 (s,
0.3 ꢀ 1H, CH—CN), 6.33 (s, 0.7 ꢀ 1H, CH—CN), 7.01-7.02 (m, 2H,
ArH), 7.15-7.20 (m, 2H, ArH), 7.25-7.30 (m, 2H, ArH), 7.36-7.39
(m, 2H, ArH); IR (KBr, cm-1) 1721, 1588, 1500, 1244, 1102, 1073;
HRMS calcd for C22H19NO335ClF (Mþ), 399.1037; found, 399.1039.
Data for 4d:. yield, 85%; 1H NMR (500 MHz, CDCl3) δ 1.17, 1.18
(2s, 3H, cyclo-CH3), 1.24, 1.30 (2s, 3H, cyclo-CH3), 1.63-1.66 (m, 1H,
cyclo-CH), 2.05-2.08 (m, 0.6 ꢀ 1H, cyclo-CH), 2.26 (s, 0.4 ꢀ 3H, Ar
—CH3), 2.34 (s, 0.6 ꢀ 3H, Ar—CH3), 2.36-2.40 (m, 0.4 ꢀ 1H, cyclo-
H), 5.02-5.08 (m, 0.6 ꢀ 2H, COOCH2), 5.10-5.16 (m, 0.4 ꢀ 2H,
COOCH2), 5.85 (d, 0.4 ꢀ 1H, J = 8.0 Hz, (Z)CHd), 5.90-5.95 (m,
0.6 ꢀ 1H, (E)CHd), 6.15 (d, 0.6 ꢀ 1H, J=14.0Hz, (E)BrHCd), 6.28(d,
0.4 ꢀ 1H, J = 8.0 Hz, (Z)BrHCd), 6.88-6.95 (m, 1H, ArH), 7.00-7.03
(m, 1H, ArH), 7.14-7.28 (m, 1H, ArH); IR (KBr, cm-1) 1726, 1631,
1401, 1384, 1003, 939; HRMS calcd for C16H18O279BrF (Mþ), 340.0474;
found, 340.0479.
Data for 4e:. yield, 88%; 1H NMR (500 MHz, CDCl3) δ 1.17, 1.19
(2s, 3H, cyclo-CH3), 1.25, 1.32 (2s, 3H, cyclo-CH3), 1.63-1.68 (m, 1H,
cyclo-H), 2.07-2.09 (m, 0.6 ꢀ 1H, cyclo-H), 2.38-2.41 (m, 0.4 ꢀ 1H,
1174
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Journal of Agricultural and Food Chemistry
ARTICLE
paper in Petri dishes. The leaves were then dipped in appropriate
solutions of the tested compounds for 5 s and exposed to dry. The dishes
were infested with 10 third-instar armyworm larvae. Percentage mor-
talities were evaluated 48 h after treatment.
Table 2. Insecticidal Activities of Compounds 3f, 3j, and 1j
against Armyworms (Mythimna separata)
concn (mg/L) 3f mortality (%) 3j mortality (%) 1j mortality (%)
Insecticidal Test for Aphids. The activities of insecticidal compounds
3f, 3j, and 1j against aphids were tested by the dipping method according
to the reported procedure.20-22 Tender shoots of soybeans with adult
aphids were dipped in appropriate solutions of the tested compounds for
5 s. The excess liquid was sucked out with filter paper. Percentage
mortalities were evaluated 24 h after treatment.
50
5
100
0
100
100
0
100
100
1
0
66.7
0.5
0
nta
0
33.3
0
0.25
nt
a nt, not tested.
Insecticidal Test for Carmine Spider Mite. The activities of insecti-
cidal compounds 3i, 3j, and 1j against carmine spider mites were tested
by the leaf-dip method according to the reported procedure.20,23
Horsebean leaves with adult mites were dipped in appropriate solutions
of the tested compounds for 5 s. The excess liquid was sucked out with
filter paper. Percentage mortalities were evaluated 24 h after treatment.
Photolysis Procedure. Ultraviolet irradiation was carried out at
365 nm with two lamps in an ultraviolet analyzer. About 30 mL of E-cis-
1j (2.85 mmol/L), cis-R-cyano-4-fluoro-3-phenoxybenzyl-2,2-dimethyl-
3-(2-dichlorovinyl)cyclopropanecarboxylate (12) (2.98 mmol/L), and
cis-R-cyano-4-fluoro-3-phenoxybenzyl-2,2-dimethyl-3-(2-methylprope-
nyl)cyclopropanecarboxylate (13) (2.90 mmol/L) in three quartzose
flasks was irradiated for 17 h in hexane. These and a mixture of 0.5 mL of
the sample solutions and 0.5 mL of benzyl alcohol in hexane (4 mmol/L)
as the internal standard were routinely inspected by GC every hour. At
the end of the reaction, inspection by GC-MS followed.24
Table 3. Insecticidal Activities of Compounds 1j and Delta-
methrin against Armyworms (Mythimna separata)
compd
LC50 (mg L-1
)
95% fiducial limit
1j
deltamethrin
0.6584
0.1486
0.5840-0.7423
0.1444-0.1529
Table 4. Insecticidal Activities of Compounds 3f, 3j, and 1j
against Aphids (Aphis craccivora)
concn (mg/L) 3f mortality (%) 3j mortality (%) 1j mortality (%)
500
50
5
100
18.8
100
100
100
100
0
0
83.7
89.5
’ RESULTS AND DISCUSSION
1
66.3
0
84.3
28.8
0
Synthesis. The synthetic procedures for the title compounds
are depicted in Scheme 1. Starting from methyl 2,2-dimethyl-3-
formylcyclopropanecarboxylate, a set of monohalovinylated
acids was synthesized through Wittig reactions. Separation of
cis-isomers (8, 9) and trans-isomers (10, 11) was performed
using their different acidities, and the title compounds were
obtained by direct esterification of acids and alcohols. The
structures of all synthesized compounds were confirmed by 1H
NMR.
Bioassay. It has become increasingly clear that the insectici-
dal activities of pyrethroids are related to their molecular
structures, so the insecticidal activities of the synthesized com-
pounds were also tested. Table 1 shows the insecticidal activities
of the title compounds against mosquito (C. pipiens pallens), a
common household pest.
0.5
0
nta
0.25
nt
a nt, not tested.
On this basis, polyfluorinated benzyl ester (3f) and R-cyano-4-
fluoro-3-phenoxybenzyl esters (1j, 3j) were selected to further
evaluate their activities against armyworms, aphids, and carmine
spider mites, three typical agricultural pests. This way, the
insecticidal activities of fluorine-containing monohalovinylated
pyrethroids could be evaluated comprehensively. Table 2 shows
the higher killing activity of 1j against armyworms; the average
mortality rate was 66.7% at 1 mg/L, which is a low concentration.
The LC50 values of compounds 1j and decamethrin were 0.1486
and 0.6548 mg/L (Table3), respectively.
The test results show that the toxic ratio of monohalovinylated
pyrethroids was closely related to their molecular structures.
First, no obvious difference was observed between monochloro-
vinylated pyrethroids (1a-c) and monobromovinylated pyre-
throids (2a-c) with the same alcohol groups. Second, the order
of the toxicities of the monohalovinylated pyrethroids with
different alcohol groups mosquito was as follows: R-cynao-3-
phenoxybenzyl esters (1c, 2c) > polyfluorinatedbenzyl esters (1f,
1i) > allylalcohol esters (1b, 2b) > alkynylalcohol esters (1a, 2a).
Third, the toxicities of cis-isomers of R-cynao-3-phenoxybenzyl
esters (1c, 1j) were higher than those of trans-isomers (3c, 3j),
whereas those of cis-isomers of polyfluorinatedbenzyl esters (1f,
1h) were lower than those of trans-isomers (3f, 3h). Fourth,
given the same stereostructures, fluorine-containing monohalo-
vinylated pyrethroids had much higher toxicities than those
without fluorine (the toxicity of 1j was about 10 times higher
than that of 1c). Finally, the toxicity of 1j against mosquito was
2.6 and 22.6 times higher than that of deltamethrin and cyper-
methrin, respectively.
Compounds 3j and 1j possessed higher insecticidal activities
against aphids;, the average mortality rates were 66.3 and 84.3%,
respectively, at low concentration (1 mg/L) (Table4). Unex-
pectedly, compound 1j demonstrated high insecticidal activity
against carmine spider mites; the average mortality rate was
91.1% at 50 mg/L concentration (Table5). Generally, the insecti-
cidal activities of pyrethroids, such as decamethrin and cyperme-
thrin, against mites are weak.25
The results of photolysis under UV light at 365 nm indicated
that 1j was easier to degrade than 12 and more difficult to
degrade than 13. These results are in agreement with the theory
(Figure 1). After 17 h of treatment, the ratios of E-cis-1j, 12, and
13 were 54, 74, and 21%, respectively. The supposed degradation
pathway under ultraviolet irradiation was shown in Figure 2,
which was similar to that in previous papers.9,10 The main
molecular ion peak detected from GC-MS was obtained from
photodegradation of compound 1j in hexane solution after 17 h.
These data support the degradation pathway we supposed in
Table 6.
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Journal of Agricultural and Food Chemistry
ARTICLE
Table 5. Insecticidal Activities of Compounds 3f, 3j, and 1j
against Carmine Spider Mites (Tetranychus cinnabarinus)
Table 6. Chromatographic and Spectroscopic Properties
of Photoproducts Arising from Ester Cleavage and Other
Processes
concn (mg/L) 3f mortality (%) 3j mortality (%) 1j mortality (%)
designation
tRa (min)
MS
500
50
5
0
0
0
0
100
7.8
100
91.1
16
17
18
19
20
21
22
2.95
100 (Mþ)
6.87
242 ([M - 1]þ)
216 ([M þ 1]þ)
232 (Mþ)
157 ([M - 1]þ)
174 (Mþ)
0
0
11.9
0
6.62
1
8.27
4.05,4.10
4.69,4.72
3.03
129 ([M þ 1]þ)
a Products arising from E-cis-1j analyzed at 120-300 °C (20 °C/
min) by GC-MS.
characteristics of high activity and low residue formation, is a
powerful candidate for pesticides. Additional studies on this com-
pound are currently underway.
’ AUTHOR INFORMATION
Corresponding Author
*Phone/fax: þ86 21 62233993. E-mail: xzzou@chem.ecnu.edu.cn.
Funding Sources
This work was financially supported by the Shanghai Foundation
of Science and Technology of China (No. 073919106).
Figure 1. Comparative photodecomposition of 12, E-cis-1j, and 13 with
similar structures in hexane using UV light.
’ ACKNOWLEDGMENT
We appreciate the support of Prof. Wen T. and Dr. Zhang B.
(Shanghai Manyi Science and Technology Co.Ltd.), and Prof.
Tao L. (Shanghai Southern Pesticides Research Center), all of
whom assisted in the test reports on insecticidal activities.
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halogen atom was replaced with one hydrogen atom at the double
bond, were designed and synthesized. Some of the compounds, such
as 3j and 1j, which were screened out, had high insecticidal activities
against wrigglers, armyworms, and aphids. Such activities were com-
parable to those of decamethrin and cypermethrin. As well, the syn-
thesized products degraded easily. The atomic economy of com-
pound 1j, which consisted of a mixture of eight chiral isomers, was
much higher than that of decamethrin with fewer isomers; thus, the
potential of this compound to improve insecticidal activities by
epimerization exists.26 Monohalovinylated pyrethroid 1j, which has
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