Ozone
Ozone is a toxic, corrosive and unstable gas, which can decompose
spontaneously to produce oxygen. This
decomposition may be explosive at elevated temperatures or in the presence
of metals.
Ozone is produced by generating a high-voltage electrical discharge in air
or oxygen. As a strong oxidant, it reacts with various oxidizable inorganic
and organic materials. The reaction with unsaturated organic compounds gives
unstable ozonides, which can decompose violently.
Name Reactions
Recent Literature
Benzyl ether protective groups are oxidatively removed by ozone under relatively
mild conditions. Reaction products are benzoic ester, benzoic acid, and the
corresponding alcohol. Subsequent deacylation with sodium methoxide affords a
convenient debenzylation technique which has been applied to various O-benzyl
protected carbohydrates.
P. Angibeaud, J. Defaye, A. Gadelle, J.-P. Utille, Synthesis,
1985,
1123-1125.
Effect of Solvent on the Rate of Ozonolysis: Development of a Homogeneous
Flow Ozonolysis Protocol
D. K. Arriaga, S. Kang, A. A. Thomas, J. Org. Chem., 2023, 88,
13720-13726.
Ozonolysis in Solvent/Water Mixtures: Direct Conversion of Alkenes to Aldehydes
and Ketones
C. E. Schiaffo, P. H. Dussault, J. Org. Chem., 2008,
73, 4688-4690.
A mild one-pot ozonolysis-oxidation process enables the synthesis of carboxylic
acids from alkenes. Conducting the ozonolysis in an aqueous organic solvent
eliminates secondary ozonide formation and the intermediates generated are
readily converted into a carboxylic acid by adding sodium chlorite. The desired
acids are isolated in high purity and high yield by simple extraction after a
reductive quench.
B. M. Cochran,
Synlett, 2016, 27, 245-248.
A low-temperature ozonolysis of alkynes enables a mild synthesis of
α-diketones.
J. L. Alterman, D. X. Vang, M. R. Stroud, L. J. Halverson, G. A. Kraus,
Org. Lett., 2020, 22, 7424-7426.
Simple Diels-Alder-derived ketals could be selectively ozonolyzed to
monoaldehydes. An overall procedure for the preparation of a key
intermediate for porphyrin and heme synthesis is described.
D. F. Taber, K. Nakajima, J. Org. Chem., 2001,
70, 2515-2517.
The diastereoselectivity of the Griesbaum coozonolysis reaction with O-methyl
2-adamantanone oxime and 4-substituted cyclohexanones reveals that the major
tetrasubstituted ozonide isomers possess cis configurations,
suggesting a preferred axial attack of the carbonyl oxide on the
cyclohexanone dipolarophiles.
Y. Tang, Y. Dong, J. M. Karle, C. A. DiTusa, J. L. Vennerstrom, J. Org.
Chem., 2004,
69, 6470-6473.
The high reactivity of ozone and its propensity to overoxidize organic
molecules, including most solvents can largely be mitigated by adsorbing both
substrate and ozone onto silica gel, providing a solvent-free oxidation method.
A flow-based packed bed reactor approach provides exceptional control of
temperature and time for oxidation of amines to nitroalkanes and the synthesis
of pyridine N-oxides.
E. A. Skrotzki, J. K. Vandavasi, S. G. Newman, J. Org. Chem., 2021, 86,
14169-14176.
A highly enantioselective method for catalytic reductive coupling of alkynes
and aldehydes afforded allylic alcohols with complete E/Z selectivity,
generally >95:5 regioselectivity, and in up to 96% ee. In conjunction with
ozonolysis, this process allows the enantioselective synthesis of α-hydroxy
ketones.
K. M. Miller, W.-S. Huang, T. F. Jamison, J. Am. Chem. Soc., 2003,
125, 3442-3443.
N-Tosyl-3-halo-3-butenylamines underwent efficient Ullmann-type
coupling to afford 2-alkylideneazetidines, which could be readily converted to
the corresponding β-lactams by oxidation with O3.
H. Lu, C. Li, Org. Lett., 2006,
8, 5365-5367.
The synthesis of α,β-unsaturated lactones from β-acetoxy aldehydes is
achieved by reaction with the lithium enolate of methyl acetate. The reaction is
relatively insensitive to structural changes in the aldehyde substrates. The
process was extended to the synthesis of five-ring lactones from α-acetoxy
aldehydes.
G. E. Keck, X.-Y. Li, C. E. Knutson,
Org. Lett., 1999, 1, 411-413.
