Synthesis of ketone from alkyl halide using α-chloro nitrone as oxidizing reagent: A new approach

Article abstract of DOI:10.1080/00397911.2010.544833

Consecutive S_N2 reaction of α-chloronitrones were studied with isopropyl halides, and the nitrones have remarkable oxidizing properties for the conversion of isopropyl halides to ketones with good yields. In addition, the side product obtained can serve as efficient dipolarophile in 1,3-dipolar cycloaddition reaction to produce spiro cycloadduct in good yield. Copyright Taylor & Francis Group, LLC.

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Synthesis of Ketone from Alkyl Halide
Using α-Chloro Nitrone as Oxidizing
Reagent: A New Approach
Bhaskar Chakraborty a & Prawin Kumar Sharma a
a Organic Chemistry Laboratory, Sikkim Government College,
Gangtok, Sikkim, India
Accepted author version posted online: 17 Nov 2011.Version of
record first published: 27 Feb 2012.
To cite this article: Bhaskar Chakraborty & Prawin Kumar Sharma (2012): Synthesis of Ketone
from Alkyl Halide Using α-Chloro Nitrone as Oxidizing Reagent: A New Approach, Synthetic
Communications: An International Journal for Rapid Communication of Synthetic Organic Chemistry,
42:12, 1804-1812
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Synthetic Communications1, 42: 1804–1812, 2012
Copyright # Taylor & Francis Group, LLC
ISSN: 0039-7911 print=1532-2432 online
DOI: 10.1080/00397911.2010.544833
SYNTHESIS OF KETONE FROM ALKYL HALIDE
USING a-CHLORO NITRONE AS OXIDIZING
REAGENT: A NEW APPROACH
Bhaskar Chakraborty and Prawin Kumar Sharma
Organic Chemistry Laboratory, Sikkim Government College, Gangtok,
Sikkim, India
GRAPHICAL ABSTRACT
Abstract Consecutive SN2 reaction of a-chloronitrones were studied with isopropyl halides,
and the nitrones have remarkable oxidizing properties for the conversion of isopropyl
halides to ketones with good yields. In addition, the side product obtained can serve as
efficient dipolarophile in 1,3-dipolar cycloaddition reaction to produce spiro cycloadduct
in good yield.
Keywords a-Chloronitrone; ketone synthesis; reusable side product
INTRODUCTION
Conventional methods for the synthesis of ketone have been well known for a
long time, including oxidation of secondary alcohols, hydration of alkynes, Friedel–
Crafts acylation, and the use of Grignard reagents. Although plenty of modern
methods are available for the synthesis of ketone from secondary alcohol,[1–11] no
such methodologies are available for ketone synthesis from isopropyl halides using
Received August 25, 2010.
Address correspondence to Bhaskar Chakraborty, Organic Chemistry Laboratory, Sikkim
Government College, Gangtok, Sikkim 737-102, India. E-mail: bchakraborty42@gmail.com
1804

SYNTHESIS OF KETONES FROM ALKYL HALIDE
1805
Scheme 1. Regents and conditions: (i) dry ether, pyridine, rt, N2 atmosphere; and (ii) dry ether, Na2CO3,
rt, N2 atmosphere.
nitrones. In this communication, we report an efficient one-pot synthesis of ketone
from isopropyl halides using a-chloronitrones 1[12,13] as oxidizing reagent
(Scheme 1, Table 1). In addition, the side product (furan derivative, 2) obtained dur-
ing ketone synthesis has been successfully used as dipolarophile in 1,3-dipolar
Table 1. Ketone synthesis using a-chloronitrones
Entry
Nitrone
Alkyl halidea
Productb
Acetone
Acetone
Time (h)
Yieldc (%)
=
=
=
=
=
=
=
=
=
1
2
3
4
5
6
7
8
9
R
R
R
R
R
R
R
R
R
Me
Me
Me
Ph
Isopropyl bromide
Isopropyl chloride
Isopropyl iodide
5
6
6
5
6
6
7
6
7
79
78
77
77
76
75
81
75
83
Acetone
Acetone
Isopropyl bromide
Isopropyl chloride
Isopropyl iodide
Ph
Ph
Acetone
Acetone
Me
Ph
1-Bromo ethyl benzene
2-Bromo butane
Bromo diphenyl methane
Acetophenone
Ethyl methyl ketone
Benzophenone
Me
aReaction conditions: a-chloronitrone (3.0198 mmol), isopropyl halide (1 equivalent), dry ether, N2
atmosphere, rt.
bAll the compounds were characterized by IR, 1H NMR, 13C NMR, MS, and HRMS spectral data.
cIsolated yield after purification.

1806
B. CHAKRABORTY AND P. K. SHARMA
Scheme 2. (i) Reaction conditions: dry ether, rt, N2 atmosphere, 6 h.
cycloaddition reaction with nitrone 1 for the production of spirocycloadduct 3 in
good yield (85%; Scheme 2). Simple nitrones can be also employed for the ketone
synthesis, but the oxidation side products are waste and the reaction is not atom
efficient. a-Chloronitrones (1) are more reactive than normal nitrones because of
the electron-withdrawing effect of chlorine and therefore can act as more powerful
oxidizing reagents than normal nitrones. A literature survey reveals that ketone syn-
thesis using nitrone as active oxidizing reagent and further use of side product
(obtained during ketone synthesis) as dipolarophile in cycloaddition reaction has
not yet known and hence can be incorporated as an important application in nitrone
chemistry.
a-Chloronitrones (1) are moderately stable and can be isolated, whereas tran-
sient nitrone 1a could not be isolated because of its high instability and undergoes
decomposition at room temperature. The lone pair of electrons of the OH group
of a-chloronitrone facilitates intramolecular SN2 reaction in the presence of pyridine
and is actually the driving force for the development of transient nitrone 1a. Nitrone
1a reacts very quickly with different isopropyl halides (SN2 reaction) and develops an
intermediate compound 1b. The labile N-O bond of 1b undergoes cleavage[14] when
the reaction mixture is stirred with solid sodium carbonate, which plays an impor-
tant role for the development of ketone and furan derivative 2 as side products in
a Kornblum-type process (Scheme 1; Table 1).
The synthetic potential of furan derivative (2) has been found to be tremendous
in the regioselective synthesis of novel 5-substituted spiro cycloadduct 3 with nitrone
1 exclusively (Scheme 2), and the spectroscopic data of 3 are similar to the spiro
cycloadducts reported earlier.[15–17]
The furan derivatives have been isolated from the organic layer and acetone
from the aqueous mixture after completion of the reaction. The yield of isolated acet-
one (75–79%) was comparatively less because after a certain amount of acetone was
removed from aqueous mixture by fractional distillation, the resulting solution
became stable because of the formation of an azeotropic mixture and resisted frac-
tional distillation. The same procedure was followed for the isolation of ethyl methyl
ketone while benzophenone and acetophenone were isolated directly from the reac-
tion mixture by column chromatography along with furan derivatives (2), and conse-
quently the yields are comparatively greater than acetone and ethyl methyl ketone.
The results are summarized in Table 1.
The beauty of the reaction is the addition of pyridine at the begining to gen-
erate transient nitrone 1a and is capable of developing furan derivative 2, which is

SYNTHESIS OF KETONES FROM ALKYL HALIDE
1807
utilized as a new efficient dipolarophile in 1,3-dipolar cycloaddition reaction and
thereby the reaction as a whole becomes atom efficient. At the outset of this work,
we were not sure about the development of transient nitrone 1a, but after com-
pletion of the study and spectral analysis of side product 2, the development of tran-
sient nitrone 1a was confirmed. The products, especially acetone, benzophenone,
acetophenone, and ethyl methyl ketone, are known compounds and spectral data
of the synthesized ketones are almost identical to the values found in literature.
For example, a single sharp singlet signal at d 2.12 and 202.00 in the NMR spectrum
(1H, 13C respectively) along with molecular ion peak at 58 and base peak at 43 in
the MS spectrum give strong evidence in favor of acetone formation. The Rf value
of the synthesized acetone was found in the solvent front because of its volatility
(difficult to identify because it evaporates rapidly) and was compared with acetone
obtained from commercial suppliers. Expected signals for benzophenone, acetophe-
1
none, and ethyl methyl ketone has been found in H NMR and 13C NMR spectra
while molecular ion peak and base peak values in the MS spectrum follow a general
pattern of fragmentation of ketones in these compounds. The oxidation side pro-
duct 2 was obtained as single isomer having E configuration in all the cases, and
the yield of the side product was almost 10–13% when isolated in pure condition.
The spiro cycloadduct 3 was obtained as regioselective single isomer predominantly
in 1,3-DCR of a-chloronitrone 1 with side product 2 in good yield (85%) when iso-
lated in pure condition. The stereochemistry of the 5-substituted regioselective spir-
ocycloadduct 3 was rationalized by considering the multiplicity of the proton signals
at 3-H, 4-H, and CHCl asymmetric centers along with their constant coupling
1
values.[18] In the H NMR spectrum of cycloadduct 3, 3-H resonates around dH
5.84 ppm while 4–H resonates around dH 3.60 ppm. The coupling constant is
J3,4 ꢀ 8.36 Hz, implying a cis relationship between H-3 and H-4. The CHCl proton
also resonates around dH 2.68 ppm. The 3-H and CHCl protons are also syn, as evi-
1
denced from their coupling constant values (J3,CHCl ꢀ 8.70 Hz). H NMR spectrum
of 3 also shows significant long-range coupling between H-4 with H-30 and
vice versa. In the mass spectrum, in addition to a molecular ion peak a prominent
base peak value is obtained for the cycloadduct and significant Mþ þ 2 peak of
characteristic relative height is also obtained for 3, which may be due to isotopic
abundance of Cl37 atom. Studies of high-resolution mass spectrographic (HRMS)
spectra show almost exact mass for the majority of the compounds. A preferential
conformation for the spiroregioselective isoxazolidine derivative 3 may be
represented in Fig. 1.
Figure 1. General conformational structure of spirocycloadduct 3.

1808
B. CHAKRABORTY AND P. K. SHARMA
EXPERIMENTAL
1H NMR spectra were recorded with a Bruker Avance DRX-300 spectrometer
(300 MHz, FT NMR) using tetramethylsilane (TMS) as internal standard. 13C
NMR spectra were recorded on the same instrument at 75 MHz. The coupling con-
stants (J) are given in hertz (Hz). Infrared (IR) spectra were obtained with a
Perkin-Elmer RX 1-881 machine as film or KBr pellets for all the products. MS
spectra were recorded with a Jeol SX-102 (FAB) instrument. The HRMS spectra
were recorded on a DART-HRMS, JMS-T100LC, Accu-TOF instrument. Elemen-
tal analyses (CHN) were performed with a Perkin-Elmer 2400 series CHN analyzer.
Thin-layer chromatography (TLC) was carried out on Fluka silica-gel TLC cards,
while column chromatography was performed with silica gel (E. Merck, India),
60–200 mesh. All other reagents and solvents were purified after receiving from com-
mercial suppliers. N-Methylhydroxylamine was purchased from Aldrich Chemical
Company and was used as received. N-Phenylhydroxylamine was prepared follow-
ing standard methods available in literature and has been used in various reported
syntheses.[19–25]
General Procedure for Synthesis of Aliphatic Ketone and Furan
Derivative 2 (Entry 1, Table 1)
=
Pyridine (1 equivalent) was added to a stirred solution of nitrone 1 (R Me;
500 mg, 3.0198 mmol) in dry ether (25 mL) and stirred at rt with a magnetic stirrer
under N2 atmosphere for 1 h, while the formation of transient nitrone 1a (not iso-
lated) was monitored by TLC (Rf ¼ 0.38). Isopropyl bromide (371.1002 mg, 1
equivalent) was added at this stage, and the reaction mixture was stirred for another
3 h until the intermediate compound 1b (not isolated) developed (monitorted by
TLC; Rf ¼ 0.40). Two g of solid Na2CO3 were added at this stage, and the reaction
mixture was stirred for another 1 h while the progress of the reaction was again
monitored by TLC (Rf ¼ 0.50, 0.96). The reaction was typically completed when
the N-O bond was cleaved. Usual workup, removal of pyridine hydrochloride,
and silica-gel column chromatographic purification using ethyl acetate–hexane pro-
=
vided furan derivative 2 (R Me) as a pale yellow gummy liquid (10%; Rf ¼ 0.50).
During workup, the furan derivative went into the organic layer while the aqueous
part containing acetone was separated from water by fractional distillation (79%;
Rf ¼ 0.96). This procedure was followed for the substrates 1–6 and 8 listed in
Table 1.
Spectroscopic Data for Ethyl Methyl Ketone (Entry 8)
Colorless liquid (78%); Rf ¼ 0.74; IR (KBr): 2940 (m), 1710 (s), 1450 (m), 1360
13
1
(m) cmꢁ1; H NMR (CDCl3): d 2.55 (q, 2H, CH2CH3), 2.14 (s, 3H, CH3), 1.24 (t,
=
3H, CH2CH3); CNMR (CDCl3): d 204.72 (C O), 46.22 (CH2CH3), 37.26 (CH3),
17.43 (CH2CH3); FAB-MS: m=z 72 (Mþ), 57 (B.P), 29. HRMS-EI: calcd. for
C4H8O (M), 72.0510; found Mþ, 72.0496.

SYNTHESIS OF KETONES FROM ALKYL HALIDE
1809
Spectroscopic Data for 2 (R¼Me; a-N-Methyl Furan Derivative; Entry
1) [(E)-1-(Dihydrofuran-2-(3H)-ylidene)-N-Methyl Methanamine)]
Pale yellow gummy liquid (10%); Rf ¼ 0.50; IR (KBr): 3120–3060 (br), 2835
1
(m), 1660 (s), 1450 (m), 1215 (m) cmꢁ1; H NMR (CDCl3): d 4.81 (br, 1H, N-H),
4.56 (s, 1H, C CH), 3.30 (N-Me), 2.50–2.16 (m, 6H); 13C NMR (CDCl3): d
=
105.26, 102.70 (double bonded carbons), 27.32, 25.00, 24.12 (3 CH2 carbons);
FAB-MS: m=z 113 (Mþ), 98, 97; HRMS-EI: calcd. for C6H11ON (M), 113.0850;
found Mþ, 113.0832. Anal. found C, 63.52; H, 9.67; N, 12.30. C6H11ON requires
C, 63.67; H, 9.79; N, 12.38%.
Spectroscopic Data for 2 (R¼Ph; a-N-Phenyl Furan Derivative; Entry
4) [(E)-1-(Dihydrofuran-2-(3H)-ylidene)-N-phenyl Methanamine)]
Dark yellow viscous liquid (11.5%); Rf ¼ 0.52; IR (KBr): 3154–3065 (br), 2865
1
(m), 1640 (s), 1440 (m), 1144 (m), 776 (s) cmꢁ1; H NMR (CDCl3): d 7.83–7.74 (m,
5H, C6H5), 6.24 (br, 1H, N-H), 2.17 (s, 1H, C CH), 1.79–1.18 (m, 6H); 13C NMR
=
(CDCl3): d 136.00, 135.18, 134.00, 132.62 (aromatic carbons), 104.20, 101.15 (double
bonded carbons), 28.55, 26.43, 24.00 (3 CH2 carbons). FAB-MS (m=z): 175 (Mþ),
98, 97, 77. HRMS-EI: calcd. for C11H13ON (M), 175.0993; found Mþ, 175.0976.
Anal. found C, 75.28; H, 7.41; N, 7.88. C11H13ON requires C, 75.39; H, 7.47; N,
7.99%.
General Procedure for Synthesis of Aromatic Ketone and Furan
Derivative 2 (Entry 9, Table 1)
=
Pyridine (1 equivalent) was added to a stirred solution of nitrone 1 (R Me,
500 mg, 3.0198 mmol) in dry ether (25 mL) and stirred at rt with a magnetic stirrer
under an N2 atmosphere for 1 h while the formation of transient nitrone 1a (not iso-
lated) was monitored by TLC (Rf ¼ 0.38). Bromo diphenyl methane (749 mg, 1
equivalent) was added at this stage, and the reaction mixture was stirred for another
5 h until the intermediate compound 1b (not isolated) was developed (monitorted by
TLC; Rf ¼ 0.40). Two g of solid Na2CO3 were added at this stage, and the reaction
mixture was stirred for another 1 h, while the progress of the reaction was again
monitored by TLC (Rf ¼ 0.42, 0.50). The reaction was typically completed when
the N-O bond was cleaved. Usual workup, removal of pyridine hydrochloride,
and silica-gel column chromatographic purification using ethyl acetate–hexane pro-
=
vided benzophenone as white flecks (83%; Rf ¼ 0.76) and furan derivative 2 (R Me)
as pale yellow gummy liquid (12%; Rf ¼ 0.50). The same procedure was followed for
the isolation of acetophenone.
Spectroscopic Data for Benzophenone (Entry 9)
White flecks (78%); mp 47 ꢂC (uncorrected); Rf ¼ 0.42; IR (KBr): 3030 (m),
1
1685 (s), 776 (s) cmꢁ1; H NMR (CDCl3): d 7.63–7.38 (m, 5H, C6H5); 13CNMR
=
(CDCl3): d 195.70 (C O), 138.22, 137.56, 137.05, 135.92, 133.74, 132.10, 130.83,

1810
B. CHAKRABORTY AND P. K. SHARMA
129.14; FAB-MS: m=z 182 (Mþ), 105 (B.P), 77, 51, HRMS-EI: calcd. for C13H10O
(M), 182.0720; found Mþ, 182.0706.
Spectroscopic Data for Acetophenone (Entry 7)
Colorless liquid (81%); Rf ¼ 0.70; IR (KBr): 3035 (m), 1682 (s) cmꢁ1; 1H NMR
(CDCl3): d 7.16–7.04 (m, 5H, C6H5), 2.38 (s, 3H, CH3); 13CNMR (CDCl3): d 200.56
=
(C O), 134.88, 132.90, 131.34, 129.54 (aromatic carbons), 28.33 (Me carbon);
FAB-MS: m=z 120 (Mþ), 105, 77 (B.P), 51; HRMS-EI: calcd. for C8H8O (M),
120.0550; found Mþ, 120.0537.
=
General Procedure for Cycloaddition Reaction of Nitrone 1 (R Ph)
=
with Furan Derivative 2 (R Ph)
=
Compound 2 (R Ph, 50 mg, 0.2855 mmol, 1 equivalent) was added to a stir-
=
red solution of N-phenyl-a-chloronitrone 1 (R Ph; 61.8375 mg, 0.2855 mmol) in
25 mL dry ether and stirred at rt with a magnetic stirrer under N2 atmosphere
for 6 h. The progress of the reaction was monitored by TLC (Rf ¼ 0.46). After com-
pletion of the reaction, the solvent was evaporated using a rotary evaporator to
afford crude cycloadduct 3, which was purified by column chromatography using
ethyl acetate–hexane and was obtained as a dark red viscous liquid 3 (85%;
Scheme 2).
(S)-4-Chloro-4-((3 S,4 S,5R)-2-phenyl-4-(phenylamino)-1,6-dioxa-2-
azaspiro[4.4]nonan-3-yl)butan-1-ol 3
3 Dark red viscous liquid. Yield 85%, Rf ¼ 0.46; IR (KBr): 3480–3296 (br),
1
2960 (m), 2422 (m), 1620 (s), 1480 (s), 1265 (m), 1044 (m), 780 (s) cmꢁ1; H NMR
(CDCl3): d 6.98–6.92 (m, 10H, 2 ꢃ C6H5), 5.84 (dd, 1H, J ¼ 8.55, 8.20 Hz, C3H),
5.00 (br, 1H, CH2OH, exchanged in D2O), 3.60 (dt, 1H, J ¼ 8.34, 8.08 Hz, C4H),
3.40 (s, 1H, N–H proton of NHPh), 2.68 (dt, J ¼ 8.60, 8.84 Hz, 1H, CHCl), 1.90
(dt, 2H, J ¼ 6.82, 6.64 Hz, C3’H), 1.50–1.12 (m, 10H); 13C NMR (CDCl3): d
137.40, 136.10, 135.42, 133.00, 132.05, 130.54, 129.00, 128.13 (aromatic carbons),
94.16 (CHCl), 87.50 (C5), 74.12 (C3), 53.00 (C4), 31.34, 28.00, 27.18, 25.00, 24.30,
22.92 (6 CH2 carbons); MS (m=z): 404 (Mþ þ 2), 402 (Mþ), 325, 310, 309, 218
(B.P), 107, 91, 77. HRMS-EI: calcd. for C22H27O3N2Cl (M), 402.1710, found Mþ,
402.1702. Anal. found C, 65.58; H, 6.69; N, 6.85; C22H27O3N2Cl requires C,
65.64; H, 6.76; N, 6.96%.

SYNTHESIS OF KETONES FROM ALKYL HALIDE
1811
CONCLUSION
Finally, we developed a new atom-efficient methodology for the ketone syn-
thesis using a-chloronitrones as oxidizing reagent and considered a further reaction
carried out on the side product with a-chloronitrones in 1,3-dipolar cycloaddition
reaction for the development of stereochemically important spirocycloadducts.
The desired cycloadducts were obtained in good yields within a short reaction time.
The newly developed side products (furan derivatives, 2) are equally effective as
dipolarophile in cycloaddition reactions, like other conventional dipolarophiles used
for cycloaddition reactions. The notable advantage offered by this method is success-
ful use of side products as dipolarophiles that can be used in various 1,3-dipolar
cycloaddition reactions for the synthesis of spirocycloadducts. The procedure also
involves simple operation, easy workup, and mild and fast reaction conditions with
good yield of products.
ACKNOWLEDGMENTS
The authors are thankful to M. P. Kharel, principal, Sikkim Government
College, for providing facilities and constant encouragement. We are pleased to
acknowledge the financial support from the University Grants Commission, New
Delhi (Grant No. 34-304=2008-SR) and also to SAIF-CDRI, Lucknow, for
providing spectral data.
REFERENCES
1. Figiel, P. J.; Kopylovich, M. N.; Lasri, J.; Guedes da Silva, M. F. C.; Frausto da Silva, J.
R.; Pombeiro, A. J. L. Solvent-free microwave-assisted peroxidative oxidation of second-
ary alcohols to the corresponding ketones catalysed by copper(II) 2,4-alkoxy-1,3,5-
triazapentadienato complexes. Chem. Commun. 2010, 46, 2766–2768.
2. Quin, W.; Jin, E.; Bao, W.; Zhang, Y. Regioselective functionalization of the imidazole
ring via (E) vinyl halides. Angew. Chem. Int. Ed. 2005, 44, 952–955.
3. Karimi, B.; Abedi, S.; Clark, J. H.; Budarin, V. Highly efficient aerobic oxidation of
alcohols using a recoverable catalyst. Angew. Chem. Int. Ed. 2006, 45, 4776–4779.
4. Kuhakarn, C.; Kittigowittana, K.; Pohmakotr, M.; Reutrakul, V. IBX=n-Bu4NBr=
CH2Cl2-H2O: A new mild system for selective oxidation of secondary alcohols. Tetra-
hedron 2005, 61, 8995–8998.
5. Mori, N.; Togo, H. A simple, efficient, and high-yield procedure for the oxidative conver-
sion of alcohols to various types of ketones using I2 and K2CO3. Tetrahedron 2005, 61,
5915–5919.
6. Choi, E.; Lee, C.; Na, Y.; Chang, S. [RuCl2(p-cymene)] on carbon: An efficient select-
ive reusable and environmentally versatile heterogenous catalyst. Org. Lett. 2002, 4,
2369–2372.
7. Kim, W. H.; Park, I. S.; Park, J. Acceptor-free alcohol dehydrogenation by recyclable
ruthenium catalyst. Org. Lett. 2006, 6, 2543–2545.
8. Zhang, S.; Xu, L.; Trudell, M. An efficient procedure of oxidation of benzyl alcohols to
corresponding carbonyl compounds with periodic acid at low temperature. Synthesis
2005, 1757–1762.
9. Zhao, X. F.; Zhang, C. A highly efficient and mild procedure for the oxidation of different
types of alcohols using TEMPO as catalyst. Synthesis 2007, 551–555.

1812
B. CHAKRABORTY AND P. K. SHARMA
10. An, G.; Lim, M.; Chun, K. S.; Rhee, R. An efficient oxidation method to convert benzylic
and allylic alcohols to ketones using Pd=C in aqueous alcohol with molecular oxygen and
NaBH4. Synlett 2007, 1, 95–97.
11. Griffith, W. P.; Jollife, J. M.; Lee, S. V.; Tiffin, P. D.; Springhorn, K.F. Oxidation of acti-
vated halides to aldehydes and ketones by N-methyl morpholine N-oxide. Synth Commun.
1992, 22, 237–243.
12. Chakraborty, B.; Kafley, S.; Chhetri, M.S. One-pot stereoselective synthesis of isoxazo-
lines from N-phenyl-a-chloronitrone. Indian J. Chem. 2009, 48B, 447–452.
13. Chakraborty, B.; Kafley, S.; Chhetri, M. S.; Samanta, A. Synthesis and antibacterial
activities of some novel isoxazolidine derivatives derived from N-phenyl-a-chloronitrone
in water. Indian J. Chem. 2010, 49B, 209–215.
14. Hoffmann, W. R.; Eichler, G.; Endesfelder, A. N-O bond cleavage in isoxazolidines.
Liebigs Ann. Chem. 1983, 2000–2007.
15. Newton, R.; Savage, P.G. Regioselective 1,3-dipolar cycloaddition reactions of
4-methylene-2-oxazolidiones with benzonitrile oxide. Australian J. Chem. 2008, 61, 432–
437.
16. Aouadik, K.; Vidal, S.; Praly, P.J. Regioselective 1,3-dipolar cycloaddition reactions for
the synthesis of spirocycloadducts. Synlett 2006, 19, 3299–3301.
17. Cacciarini, M.; Cordero, F. M.; Faggi, C.; Goti, A. Cycloaddition reactions of
C,N-diphenyl nitrone to methylene-c-butyrolactones. Molecules 2000, 5, 637–642.
18. Deshong, P.; Li, W.; Kennington, J. W. Ammon, H. L. A nitrone-based cycloaddition
approach to the synthesis of the glycosyl system of nogalomycin, menogaril, and their
congeners. J. Org. Chem. 1991, 56, 1364–1373.
19. Chakraborty, B.; Sharma, P. K.; Chhetri, M. S.; Kafley, S. Introducing a new method-
ology of aldehyde synthesis from alkyl halide using a-chloronitrone as a new, stable,
and potential oxidizing reagent. Rasayan J. Chem. 2009, 2(4), 946–952.
20. Chakraborty, B.; Sharma, P. K.; Chhetri, M. S.; Kafley, S. New and efficient method for
the synthesis of aldehydes using a-chloronitrones as stable and potential oxidizing reagent.
J. Indian Chem. Soc. 2011, 88, 245–250.
21. Chakraborty, B.; Chhetri, M. S. Synthetic potentiality of a-chloronitrone in aldehyde syn-
thesis: A new approach. Indian J. Chem. 2008, 47B, 485–488.
22. Chakraborty, B.; Chhetri, M S.; Samanta, A. A green approach in aqueous-phase syn-
thesis of isoxazolidine derivatives from N-phenyl-a-aminonitrone and their antibacterial
activities. Indian J. Chem. 2010, 49B, 1155–1160.
23. Chakraborty, B.; Rai, N.; Chhetri, M. S. One-pot stereo, and regioselective synthesis of
novel spiro isoxazolidine derivatives with c-butyrolactone and a-methyl=phenyl furan
derivatives using a-amino nitrone and their antibacterial activities. Rasayan J. Chem.
2010, 3(1), 506–511.
24. Chakraborty, B.; Kafley, S.; Chhetri, M. S. Synthesis and 1,3-dipolar cycloaddition reac-
tion of N-cyclohexyl-a-amino nitrone in water: A new approach. Indian J. Heterocycl.
Chem. 2008, 18, 201–202.
25. Chakraborty, B.; Chhetri, M.S. Synthesis and 1,3-dipolar cycloaddition reaction of
N-phenyl-a-N,N-dimethyl amino and N-phenyl-5-hydroxy nitrones with N-substituted
maleimides. Indian J. Heterocycl. Chem. 2008, 17, 213–216.