Low-Temperature Ozonolysis of 2-Alkenyl-1,1-dichlorocyclopropanes

Article abstract of DOI:10.1134/S1070428018030028

Low-temperature ozonolysis of 2-alkenyl-1,1-dichlorocyclopropanes under different conditions (O₃/MeOH–CH₂Cl₂–NaOH, O₃/MeOH or O₃/CH₂Cl₂–AcOH with subsequent treatment with semica

Full text of DOI:10.1134/S1070428018030028

ISSN 1070-4280, Russian Journal of Organic Chemistry, 2018, Vol. 54, No. 3, pp. 377–381. © Pleiades Publishing, Ltd., 2018.
Original Russian Text © Yu.V. Legostaeva, L.R. Garifullina, G.Z. Raskil’dina, R.M. Sultanova, G.Yu. Ishmuratov, S.S. Zlotskii, 2018, published in Zhurnal
Organicheskoi Khimii, 2018, Vol. 54, No. 3, pp. 373–377.
Low-Temperature Ozonolysis
of 2-Alkenyl-1,1-dichlorocyclopropanes
Yu. V. Legostaevaa, L. R. Garifullinaa, G. Z. Raskil’dinab,* R. M. Sultanovaa, b,
G. Yu. Ishmuratova, and S. S. Zlotskiib
a Ufa Institute of Chemistry, Russian Academy of Sciences, pr. Oktyabrya 71, Ufa, 450054 Bashkortostan, Russia
b Ufa State Petroleum Technological University, ul. Kosmonavtov 1, Ufa, 450062 Bashkortostan, Russia
*e-mail: graskildina444@mail.ru
Received October 4, 2017
Abstract—Low-temperature ozonolysis of 2-alkenyl-1,1-dichlorocyclopropanes under different conditions
(O3/MeOH–CH2Cl2–NaOH, O3/MeOH or O3/CH2Cl2–AcOH with subsequent treatment with semicarbazide
hydrochloride) afforded the corresponding carbonyl and carboxy derivatives at different ratios, depending on
the substrate structure and workup procedure. Peroxide products of ozonolysis of 1,1-dichloro-2-ethenyl-
cyclopropane [3-(2,2-dichlorocyclopropyl)-1,2,4-trioxolane and (2,2-dichlorocyclopropyl)(methoxy)methyl
hydroperoxide] turned out to be more stable than those derived from 1,1-dichloro-2-ethenyl-2-methylcyclo-
propane and were isolated in the pure state.
DOI: 10.1134/S1070428018030028
Ozonolysis is a modern method of oxidative cleav-
age of alkenes at the C=C double bond and is widely
used in the synthesis of carbonyl compounds and their
derivatives [1–3]. For example, oxidation of olefins
with ozones, followed by treatment with reducing
agents (PPh3 or Et3N) provides a convenient method
for the preparation of aldehydes [4]. We previously
showed that semicarbazide and hydroxylamine hydro-
chlorides are efficient in the transformation of inter-
mediate peroxides to carbonyl compounds and their
derivatives in alcohols [5], as well as in the preparation
of acids via decomposition of ozonides obtained from
terminal alkenes [6]. This approach was used to
develop a one-pot procedure for the synthesis of
alkoxy- and phenoxyacetic acids by low-temperature
ozonolysis of allyl ethers and subsequent transforma-
tion of intermediate ozonides by the action of semi-
carbazide hydrochloride [7, 8]. In continuation of
studies in this line, herein we report ozonolysis of
1,1-dichloro-2-alkenylcyclopropanes 1a–1c prepared
by dichlorocyclopropanation of isoprene and 2,3-di-
methylbutadiene [9].
different solvent systems (MeOH–CH2Cl2–NaOH,
MeOH, and CH2Cl2–AcOH) at –78 to –60°C. The
composition and ratio of peroxide and non-peroxide
ozonolysis products depended on both substrate struc-
ture and conditions for the treatment of intermediate
peroxides.
The ozonolysis of 1,1-dichloro-2-ethenylcyclo-
propane (1a) in MeOH–CH2Cl2–NaOH at –70°C
(method a), followed by treatment of the reaction mix-
ture and silica gel chromatography, gave an insepa-
rable mixture of 1,2,4-trioxolane 2a and its transforma-
tion products, aldehyde 4a and ester 5a, at a ratio of
1:1:3 in an overall yield of 21% (Scheme 1). The ratio
1
2a:4a:5a was determined by H NMR spectroscopy
from the intensities of non-overlapping signals of
the OCH2O group of 2a (δ 5.10 ppm), aldehyde proton
of 4a (δ 10.40 ppm), and methoxy protons of 5a
(δ 3.65 ppm). The presence of a 1,2,4-trioxolane frag-
ment in ozonide 2a was confirmed by the signals at
1
δ 5.10 and 5.25 ppm in the H NMR spectrum and at
δC 93.18 and 100.23 ppm in the 13C NMR spectrum,
which are typical of the OCH2O and OCHRO groups.
It is known [10] that reaction medium plays an im-
portant role in the stabilization of zwitterions generat-
ed by ozonolysis of C=C double bonds. Therefore,
the ozonolysis of alkenes 1a–1c was carried out in
The oxidation of 1a with ozone in methanol at
–78°C, followed by treatment with semicarbazide
hydrochloride (method b), afforded methoxy hydro-
peroxide 3a and semicarbazone 6a which were isolated
377

LEGOSTAEVA et al.
378
Scheme 1.
O
O
Cl
Cl
Cl
CHO
O
–HCOOH
Cl
O3, MeOH–CH2Cl2–NaOH
–70°C
2a
4a
a
2a:4a:5a = 1:1:3
OOH
OMe
Cl
Cl
Cl
COOMe
–H2O
Cl
3a
5a
CH2
(1) O3, MeOH, –78°C
(2) H2NC(O)NHNH2·HCl
Cl
Cl
Cl
Cl
[H]
3a
[4a]
NNHC(O)NH2
b
1a
22%
6a, 7%
[H]
4a
6a
(1) O3,CH2Cl2–AcOH, –65°C
(2) H2NC(O)NHNH2·HCl
OOH
OAc
22.5%
9%
Cl
Cl
c
O
Cl
Cl
Cl
COOH
7a
OAc
–H2O
–H2O
Cl
8a
9a, 20%
Scheme 2.
O
O
O3, MeOH–CH2Cl2–NaOH
–70°C
Cl
Cl
Cl
Cl
CHO
O
a
–HCOOH
Me
Me
2b
4b, 40%
Cl
Cl
NNHC(O)NH2
Me
OOH
(1) O3, MeOH, –78°C
(2) H2NC(O)NHNH2·HCl
CH2
Cl
Cl
Cl
Cl
6b, 8%
[H]
[4b]
OMe
Me
b
Me
Cl
Cl
CH(OMe)2
Me
1b
3b
10b, 56%
[H]
4b
6b
(1) O3,CH2Cl2–AcOH, –65°C
(2) H2NC(O)NHNH2·HCl
OOH
Cl
Cl
23%
6%
OAc
Me
c
O
Cl
Cl
Cl
Cl
7b
COOH
Me
OAc
–H2O
–H2O
Me
8b
9b, 57%
from the reaction mixture. Obviously, hydroperoxide
3a is reduced to aldehyde 4a which then reacts with
semicarbazide hydrochloride to form semicarbazone
6a. The ozonolysis of 1a in methylene chloride–acetic
acid (method c) involved intermediate formation of
unstable acetoxy hydroperoxide 7a. Subsequent trans-
formations of the latter followed two paths: reduction
to aldehyde 4a and its conversion to semicarbazone 6a
and dehydration to mixed anhydride 8a whose hydrol-
ysis led to carboxylic acid 9a (Scheme 1).
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 54 No. 3 2018

LOW-TEMPERATURE OZONOLYSIS OF 2-ALKENYL-1,1-DICHLOROCYCLOPROPANES
379
Unlike 1a, in the ozonolysis of its homolog, 1,1-di-
chloro-2-ethenyl-2-methylcyclopropane (1b), in
MeOH–CH2Cl2–NaOH (method a) we isolated only
aldehyde 4b in 40% yield. When the reaction was
carried out in methanol at –78°C (method b), methoxy
hydroperoxide 3b was likely to be reduced to aldehyde
4b which was then converted to acetal 10b or semi-
carbazone 6b (Scheme 2). According to method c, the
transformations of intermediate acetoxy peroxide 7b
were analogous to those of 7a.
Ozonolysis of 1,1-dichloro-2-alkenylcyclo-
propanes (general procedure). a. An ozone–oxygen
mixture was bubbled over a period of 20 min (ozonizer
efficiency 9.7 mmol O3/h) through a solution of
3.3 mmol of alkene 1a or 1b in a mixture of 6.6 mL of
a 2.5 M solution of sodium hydroxide in methanol and
27 mL of methylene chloride, cooled to –70°C. The
mixture was purged with argon, 30 mL of tert-butyl
methyl ether and 15 mL of water were added, and the
mixture was stirred for 1 h at room temperature. The
organic phase was separated, the aqueous phase was
extracted with tert-butyl methyl ether (50 mL), the
extracts were combined with the organic phase and
dried over Na2SO4, and the solvent was evaporated.
The ozonolysis of 1,1-dichloro-2-methyl-2-(prop-1-
en-2-yl)cyclopropane (1c) in methylene chloride–
acetic acid at –65°C, followed by treatment with
semicarbazide hydrochloride, gave only methyl ketone
4c in more than 70% yield (Scheme 3).
b. An ozone–oxygen mixture was bubbled through
a solution of 3.3 mmol of alkene 1a or 1b in 30 mL of
methanol, cooled to –78°C, until the reaction mixture
turned blue. The mixture was purged with argon, and
1.3 g (11.6 mmol) of semicarbazide hydrochloride was
added at –50°C. The mixture was stirred at room
temperature until peroxide products were no longer
detected. It was then evaporated, the residue was
dissolved in chloroform (150 mL), the solution was
washed with water (4×15 mL) and dried over Na2SO4,
and the solvent was evaporated.
Scheme 3.
CH2
Me
O
(1) O3,CH2Cl2–AcOH, –65°C
(2) H2NC(O)NHNH2·HCl
Cl
Cl
Cl
Cl
Me
c
Me
Me
1c
4c, 74%
The obtained results are very consistent with the
available published data on the effect of steric factors
on the selectivity of reductive ozonolysis of alkenes in
the presence of nitrogen-containing compounds [11].
c. An ozone–oxygen mixture was bubbled through
a solution of 3.3 mmol of alkene 1a or 1b in a mixture
of 20 mL of methylene chloride and 1.8 mL of acetic
acid, cooled to –65°C, until the reaction mixture turned
blue. The mixture was purged with argon, 1.3 g
(11.6 mmol) of semicarbazide hydrochloride was
added at –65°C, and the mixture was stirred at room
temperature until peroxide products were no longer
detected. The products were isolated as described
above in b.
Thus, the composition and ratio of peroxide and
non-peroxide products of low-temperature ozonolysis
of 1,1-dichloro-2-alkenylcyclopropanes depend on
both substrate structure and procedure for the treat-
ment of intermediate peroxides.
EXPERIMENTAL
The IR spectra were recorded on a Shimadzu IR
Prestige-21 spectrometer with Fourier transform from
Ozonolysis of 1,1-dichloro-2-ethenylcyclo-
propane (1a). a. Removal of the solvent left 0.11 g of
a product mixture containing ozonide 2, aldehyde 3a,
and ester 4 at a ratio of 1:1:3.
1
13
samples prepared as thin films. The H and C NMR
spectra were recorded on a Bruker Avance III 500
high-resolution spectrometer at 500 and 125.76 MHz,
respectively, using CDCl3 as solvent and TMS as
internal standard. GLC analyses were performed with
a Chrom-5 chromatograph equipped with a 1.2-m
column packed with 5% SE-30 on Chromaton N-AW-
DMCS (0.16–0.20 mm); oven temperature 50–300°C;
carrier gas helium. The optical rotations were meas-
ured on a Perkin Elmer 241-MC polarimeter. Silica gel
plates (Sorbfil, Russia) were used for TLC monitoring.
The products were isolated by column chromatography
on silica gel (70–230 mesh, Lancaster, UK). The
ozonizer efficiency was 40 mmol O3 per hour.
3-(2,2-Dichlorocyclopropyl)-1,2,4-trioxolane
1
(2a). IR spectrum, ν, cm–1: 1100, 852. H NMR spec-
trum, δ, ppm: 1.20 d (1H, 3-H, J = 3.4 Hz), 1.85 d (1H,
3-H, J = 5.8 Hz), 1.25–1.30 m (1H, 1-H), 5.10 m (2H,
OCH2O), 5.25 m (1H, OCHO). 13C NMR spectrum, δC,
ppm: 27.45 t (C3), 31.00 d (C1), 59.06 s (C2), 93.18 t
(OCH2O), 100.23 d (OCHO).
2,2-Dichlorocyclopropane-1-carbaldehyde (4a).
1
IR spectrum, ν, cm–1: 2852, 1707. H NMR spectrum,
δ, ppm: 1.10–1.35 m, 2.05–2.20 m (2H, 3-H), 1.84–
1.90 m (1H, 1-H), 10.40 s (CHO). 13C NMR spectrum,
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 54 No. 3 2018

LEGOSTAEVA et al.
380
δC, ppm: 26.53 t (C3), 33.44 d (C1), 59.25 s (C2),
195.34 d (CHO).
petroleum ether–t-BuOMe, 4:1) gave 0.2 g (40%) of
aldehyde 4b.
2,2-Dichloro-1-methylcyclopropane-1-carbalde-
Methyl 2,2-dichlorocyclopropane-1-carboxylate
1
(5a). IR spectrum: ν 1734 cm–1. H NMR spectrum, δ,
hyde (4b). Colorless oily material. IR spectrum, ν,
1
cm–1: 2852, 1725. H NMR spectrum, δ, ppm: 1.35–
ppm: 1.00–1.20 m and 1.70–1.80 m (1H each, 3-H),
2.55 t (1H, 1-H, J = 13.1, 6.5 Hz), 3.65 s (3H, OCH3).
13C NMR spectrum, δC, ppm: 26.19 t (C3), 28.06 d
(C1), 51.83 s (OCH3), 59.06 s (C2), 172.70 s (C=O).
1.40 m and 2.18–2.22 m (2H, 3-H), 1.42 s (3H, CH3),
9.95 s (1H, CHO). 13C NMR spectrum, δC, ppm:
14.28 q (CH3), 30.92 t (C3), 38.56 s (C1), 63.51 s (C2),
197.15 d (CHO). Found, %: C 39.25; H 3.95; Cl 46.34.
C5H6Cl2O. Calculated, %: C 39.20; H 3.88; Cl 46.27.
b. Chromatographic separation of 0.63 g of the
isolated material (SiO2, petroleum ether–t-BuOMe,
10:1, MeOH) gave 0.12 g (24%) of aldehyde 4b,
0.37 g (56%) of acetal 10b, and 0.05 g (8%) of
semicarbazone 6b.
2,2-Dichloro-1-methylcyclopropane-1-carbalde-
hyde semicarbazone (6b). Light yellow crystals,
mp 178–180°C. IR spectrum: ν 1691 cm–1 (C=N).
1H NMR spectrum, δ, ppm: 1.40–1.43 m and 2.22–
2.24 m (2H, 3-H), 1.51 s (3H, CH3), 5.90 br.s (2H,
NH2), 6.04 br.s (1H, NH), 6.90 s (1H, CH=N).
13C NMR spectrum, δC, ppm: 14.06 q (CH3), 29.63 t
(C3), 32.70 s (C1), 58.59 s (C2), 144.51 d (CH=N),
155.94 s (C=O). Found, %: C 34.31; H 4.32; Cl 33.75.
C6H9Cl2N3O. Calculated, %: C 34.29; H 4.37;
Cl 33.62.
1,1-Dichloro-2-(dimethoxymethyl)-2-methyl-
cyclopropane (10b). Colorless oily material. 1H NMR
spectrum, δ, ppm: 1.38–1.41 m and 2.20–2.25 m (2H,
3-H), 1.45 s (3H, CH3), 3.35 s (6H, OCH3), 4.27 s (1H,
CH). 13C NMR spectrum, δC, ppm: 15.60 q (CH3),
30.28 t (C3), 39.50 s (C2), 55.05 s (C1), 56.01 (OCH3),
109.27 d (CH). Found, %: C 42.23; H 6.08; Cl 35.62.
C7H12Cl2O2. Calculated, %: C 42.23; H 6.08; Cl 35.62.
c. Chromatographic separation of 0.51 g of the
isolated material (SiO2, petroleum ether–t-BuOMe,
10:1 to 1:1, MeOH) gave 0.12 g (23%) of 4b, 0.31 g
(57%) of 9b, and 0.04 g (6%) of 6b.
2,2-Dichloro-1-methylcyclopropane-1-carboxylic
acid (9b). White crystals, mp 63–64°C; published data
[13]: mp 61–62°C. IR spectrum: ν 1725 cm–1 (C=O).
1H NMR spectrum, δ, ppm: 1.48 d (1H, 3-H, J =
8.7 Hz), 2.70 d (1H, 3-H, J = 7.6 Hz), 1.59 s (3H,
CH3), 11.00 br.s (1H, OH). 13C NMR spectrum,
δC, ppm: 17.97 q (CH3), 31.08 t (C3), 35.73 s (C1),
62.58 s (C2), 175.38 s (C=O). Found, %: C 35.53;
H 3.58; Cl 41.95. C5H6Cl2O2. Calculated, %: C 35.48;
H 3.50; Cl 41.86.
b. Chromatographic separation of 0.20 g of the
isolated material (SiO2, petroleum ether–t-BuOMe,
10:1 to 1:1, MeOH) gave 0.14 g (22%) of 3a and
0.05 g (7%) of 6a.
(2,2-Dichlorocyclopropyl)(methoxy)methyl
hydroperoxide (3a). Oily material. IR spectrum, ν,
cm–1: 3405 (OOH), 1112 (C–OO), 912 (O–O).
1H NMR spectrum, δ, ppm: 1.42 t (1H, 1-H, J = 7.3,
15.3 Hz), 1.75 d (1H, 3-H, J = 7.2 Hz), 1.90 d (1H,
3-H, J = 8.8 Hz), 3.40 s (3H, OCH3), 4.25 d (1H, CH,
J = 6.8 Hz), 10.20 br.s (1H, OOH). 13C NMR spec-
trum, δC, ppm: 26.35 t (C3), 32.10 d (C1), 52.68 q
(OCH3), 58.16 s (C2), 103.30 d (CH). Found, %:
C 32.11; H 4.31; Cl 37.91. C5H8Cl2O3. Calculated, %:
C 32.00; H 4.25; Cl 37.98.
2,2-Dichlorocyclopropane-1-carbaldehyde semi-
carbazone (6a). White crystals, mp 143–145°C. IR
1
spectrum: ν 1683 cm–1 (C=N). H NMR spectrum, δ,
ppm: 1.70 d (1H, 3-H, J = 7.1 Hz), 1.84 d (1H, 3-H,
J = 8.7 Hz), 2.15 t (1H, 1-H, J = 7.5, 14.9 Hz),
5.90 br.s (1H, NH), 6.85 d (1H, CH, J = 6.6 Hz),
9.25 br.s (1H, NH). 13C NMR spectrum, δC, ppm:
24.17 t (C3), 31.71 d (C1), 59.34 s (C2), 140.28 d
(CH=N), 158.13 s (C=O). Found, %: C 30.63; H 3.60;
Cl 36.17; N 21.44. C5H7Cl2N3O. Calculated, %:
C 30.57; H 3.65; Cl 36.11; N 21.49.
c. Chromatographic separation of 0.30 g of the
isolated material (SiO2, petroleum ether–t-BuOMe,
10:1 to 1:1, MeOH) gave 0.10 g (23%) of 4a, 0.10 g
(20%) of 9a, and 0.06 g (9%) of 6a.
2,2-Dichlorocyclopropane-1-carboxylic acid (9a).
White crystals, mp 75–76°C; published data [12]:
mp 76–77°C. IR spectrum, ν, cm–1: 3096, 1693 (C=O).
1H NMR spectrum, δ, ppm: 1.12–1.33 m and 2.01–
2.18 m (2H, 3-H), 1.70–1.78 m (1H, 1-H), 10.50 br.s
13
(1H, OH). C NMR spectrum, δC, ppm: 26.41 t (C3),
33.13 d (C1), 59.25 s (C2), 176.16 s (COOH). Found,
%: C 31.00; H 2.60; Cl 45.75. C4H4Cl2O2. Calculated,
%: 31.08; H 2.67; Cl 45.69.
Ozonolysis of 1,1-dichloro-2-methyl-2-ethenyl-
cyclopropane (1b). a. Chromatographic separation of
0.27 g of the isolated material (SiO2, petroleum ether,
Ozonolysis of 1,1-dichloro-2-methyl-2-(prop-
1-en-2-yl)cyclopropane (1c). c. Chromatographic
separation of 0.54 g of the isolated material (SiO2,
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 54 No. 3 2018

LOW-TEMPERATURE OZONOLYSIS OF 2-ALKENYL-1,1-DICHLOROCYCLOPROPANES
381
3. Hon, Y.-S. and Wong, Y.-C., Tetrahedron Lett., 2005,
petroleum ether– t-BuOMe, 10:1 to 1:1, MeOH) gave
0.41 g (74%) of ketone 4c.
vol. 46, p. 1365.
4. Ishmuratov, G.Yu., Legostaeva, Yu.V., Botsman, L.P.,
and Tolstikov, G.A., Russ. J. Org. Chem., 2010, vol. 46,
p. 1593.
5. Ishmuratov, G.Yu., Legostaeva, Yu.V., Garifullina, L.R.,
Botsman, L.P., Idrisova, Z.I., Muslukhov, R.R.,
Ishmuratova, N.M., and Tolstikov, G.A., Russ. J. Org.
Chem., 2013, vol. 49, p. 1409.
6. Ishmuratov, G.Yu., Legostaeva, Yu.V., Garifullina, L.R.,
Botsman, L.P., Muslukhov, R.R., Ishmuratova, N.M.,
and Tolstikov, G.A., Russ. J. Org. Chem., 2014, vol. 50,
p. 928.
7. Raskil’dina, G.Z., Legostaeva, Yu.V., Garifullina, L.R.,
Sultanova, R.M., Ishmuratov, G.Yu., and Zlotskii, S.S.,
Dokl. Chem., 2015, vol. 462, p. 127.
8. Raskil’dina, G.Z., Legostaeva, Yu.V., Garifullina, L.R.,
Sultanova, R.M., Ishmuratov, G.Yu., and Zlotskii, S.S.,
Lett. Org. Chem., 2016, vol. 13, p. 652.
9. Raskil’dina, G.Z., Borisova, Yu.G., Yanybin, V.M., and
Zlotskii, S.S., Pet. Chem., 2017, vol. 57, p. 278.
10. Van Ornum, S.G., Champeau, R.M., and Pariza, R.,
1-(2,2-Dichloro-1-methylcyclopropyl)ethanone
(4c). Colorless oily material. IR spectrum: ν 1717 cm–1
1
(C=O). H NMR spectrum, δ, ppm: 1.25 s (3H, CH3),
1.45 d (1H, 3-H, J = 8.9 Hz), 2.40 d (1H, 3-H, J =
7.5 Hz), 1.65 s (3H, CH3). 13C NMR spectrum, δC,
ppm: 18.13 q (CH3), 27.85 q (CH3), 29.59 t (C3),
41.06 s (C1), 66.98 s (C2), 201.86 s (C=O). Found, %:
C 43.14; H 4.83; Cl 42.45. C6H8Cl2O. Calculated, %:
C 43.09; H 4.75; Cl 42.39.
This study was performed under financial support
by the Russian Academy of Sciences (program 44:
“Fundamentals of Chemistry. Chemo-, Regio-, and
Stereoselective Transformations of Lipids, Terpenoids,
Steroids, and Monosaccharides in Directed Syn-
theses”) and by the Russian Science Foundation
(project no. 15-13-10034) using the equipment of the
Chemistry Joint Center (Ufa Institute of Chemistry,
Russian Academy of Sciences).
Chem. Rev., 2006, vol. 106, p. 2990.
11. Willand-Charnley, R., Fisher, T.J., Johnson, B.M., and
REFERENCES
Dussault, P.H., Org. Lett., 2012, vol. 14, p. 2242.
1. The Chemistry of Peroxides, Rappoport, Z., Ed.,
12. Orchin, M. and Herrick, E.C., J. Org. Chem., 1959,
Chichester: Wiley, 2006, vol. 2, part 1.
vol. 24, p. 139.
2. McGuire J., Bond G., and Haslam, P.J., Handbook of
Chiral Chemicals, Ager, D., Ed., Boca Raton: Taylor &
Francis, 2006, 2nd ed.
13. DeWeese, F.T., Minter, D.E., Nosovitch, J.T., and
Rudel, M.G., Tetrahedron, 1986, vol. 42, p. 239.
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