POTASSIUM PERMANGANATE COPPER(II) SULFATE 1
Potassium Permanganate Copper(II) Oxidation of Sulfides and Selenides. Under similar condi-
tions, sulfides and selenides are converted to sulfones and sele-
Sulfate
nones.4
KMnO4 CuSO4 · 5H2O
Oxidation of Primary Alcohols and Ä…,É-Diols. If a base
(Cu(OH)2·CuCO3 or KOH) is added, primary alcohols are oxi-
(KMnO4) dized to the corresponding carboxylic acids in yields of 80 96%
[7722-64-7] KMnO4 (MW 158.04) and in a competition experiment it was found that primary al-
cohols are oxidized in preference to secondary alcohols.1 Under
InChI = 1/K.Mn.4O/q+1;;;;;-1/rK.MnO4/c;2-1(3,4)5/q+1;-1
similar conditions, Ä…,É-diols are converted to lactones in good
InChIKey = VZJVWSHVAAUDKD-QPPHZJHPAS
yields (eq 1).
(CuSO4·5H2O)
[7758-99-8] CuO4S (MW 249.72)
Oxidation of Alkenes. The presence of a small additional
InChI = 1/Cu.H2O4S.5H2O/c;1-5(2,3)4;;;;;/h;(H2,1,2,3,4);5*
amount of moisture along with some t-butyl alcohol introduces
1H2/q+2;;;;;;/p-2/fCu.O4S.5H2O/qm;-2;;;;;
a modification to the reactivity of the reagent by formation of
InChIKey = JZCCFEFSEZPSOG-QLBZKNHHCL
an  omega phase15 surrounding the solid support. Under such
(oxidant; capable of converting saturated primary alcohols into conditions alkenes are oxidized to Ä…-diketones and/or Ä…-hydroxy
carboxylic acids,1 saturated secondary alcohols into ketones,2 ketones. For example, when 200 L of water was added to a
Ä…,²-unsaturated alcohols into Ä…,²-unsaturated ketones,3 dialkyl finely ground mixture of potassium permanganate (4.0 g) and
and diaryl sulfides into sulfones,4 diphenyl selenide into diphenyl copper(II) sulfate pentahydrate (2.0 g) followed by cyclooctene
selenone,4 Ä…,É-diols into lactones,1 alkenes into diketones (4 mmol) in CH2Cl2 (15 mL) and t-butyl alcohol (1.0 mL), Ä…-
and Ä…-hydroxy ketones,5 É-hydroxy alkenes into É-lactones,6 hydroxycyclooctanone was obtained in 50% yield after refluxing
1,5-dienes into 5-substituted butanolides,7 and 5-unsaturated for 30 min. Under similar conditions, but with the addition of
steroids into the corresponding 5²,6²-epoxy steroids) Cu(OAc)2·H2O (1.0 g), 1,2-cyclooctadione was obtained in 48%
yield (eq 2).
Physical Data: mixture of high melting solids; see entries for
Potassium Permanganate and Copper(II) Sulfate.
Solubility: sol cold H2O; insol CH2Cl2.
Form Supplied in: KMnO4: purple solid. CuSO4·5H2O: blue
(1)
solid.
HO 83%
O
Handling, Storage, and Precautions: oxidant; store in glass con-
HO
tainers at rt. O
OO
(2)
Introduction. The use of KMnO4 adsorbed on a solid sup-
50% 48%
OH O
port as a heterogeneous oxidant in nonaqueous solvents such as
CH2Cl2 has two very practical advantages. First, in common with
With some alkenes, epoxides are obtained instead of ketones.
most heterogeneous reactions, the product can be isolated simply
For example, 5-unsaturated steroids are readily converted into
by filtering to remove the spent oxidant, followed by flash evapora-
the corresponding 5²,6²-epoxides in 90 95% yield (eq 3).5,8
tion of the solvent. Second, adsorption of potassium permanganate
onto a solid support remarkably improves its selectivity. Various
O O
supports have been used (e.g. molecular sieves,9 Alumina,10,11
and silica10 13) with Copper(II) Sulfate being the most conve-
H H
(3)
nient and versatile.
90%
H H H H
The water of hydration is important; without it very little or no
AcO AcO
product is obtained.2 While the role of water in controlling the
O
nature of the products is empirically well documented, a theo-
retical understanding of its function has been the subject of only
preliminary discussions.11,14
Oxidation of É-Hydroxy Alkenes and 1,5-Dienes. When the
omega phase is produced by adding 400 L of water to powdered
Oxidation of Secondary Alcohols to Ketones. When potas-
KMnO4 (8 g) and CuSO4·5H2O (4 g), É-hydroxy alkenes are
sium permanganate (3 g) and copper(II) sulfate pentahydrate (2 g)
oxidized with the loss of one or more carbons (eq 4).6
are ground together, a reagent capable of oxidizing both saturated
and Ä…,²-unsaturated secondary alcohols into the corresponding
R2
ketones is produced. When the alcohols (3 mmol) dissolved in
R1
R2
(4)
OH
20 mL of CH2Cl2 are added and the heterogeneous mixture re- O
52 84%
R1 O
fluxed for several hours, ketones are formed in excellent yields;3
however, primary alcohols, alkenes, and alcohols unsaturated at a
more remote position are not oxidized unless water or a base are
Under similar conditions, 1,5-dienes are converted to 5-sub-
added.
stituted butanolides,7 as opposed to 2,5-bis(hydroxymethyl)tetra-
Avoid Skin Contact with All Reagents
2 POTASSIUM PERMANGANATE COPPER(II) SULFATE
hydrofurans which are formed in the corresponding aqueous re- 7. Baskaran, S.; Islam, I.; Vankar, P. S.; Chandrasekaran, S., J. Chem. Soc.,
Chem. Commun. 1992, 626.
actions (eq 5).16
8. Syamala, M. S.; Das, J.; Baskaran, S.; Chandrasekaren, S., J. Org. Chem.
1992, 57, 1928.
HO OH
KMnO4
9. Regen, S. L.; Koteel, C., J. Am. Chem. Soc. 1977, 99, 3837.
H2O O
10. Quici, S.; Regen, S. L., J. Org. Chem. 1979, 44, 3436.
(5)
11. Lee, D. G.; Chen, T.; Wang, Z., J. Org. Chem. 1993, 58, 2918.
KMnO4, CuSO4
CH2Cl2
12. Ferreira, J. T. B.; Cruz, W. O.; Vieira, P. C.; Yonashiro, M., J. Org. Chem.
OH
1987, 52, 3698.
O
O
13. Clark, J. H.; Cork, D. G., J. Chem. Soc., Chem. Commun. 1982, 635.
14. Lee, D. G.; Noureldin, N. A., J. Am. Chem. Soc. 1983, 105, 3188.
15. Liotta, C. L.; Burgess, E. M.; Ray, C. C.; Black, E. D.; Fiar, B. E. In
Phase-Transfer Catalysis; New Chemistry, Catalysts, and Applications;
1. Jefford, C. W.; Wang, Y., J. Chem. Soc., Chem. Commun. 1988, 634.
Starks, C. M., Ed.; American Chemical Society: Washington, 1987; p
2. Menger, F. M.; Lee, C., J. Org. Chem. 1979, 44, 3446.
15.
3. Noureldin, N. A.; Lee, D. G., Tetrahedron Lett. 1981, 22, 4889.
16. Walba, D. M.; Przybyla, C. A.; Walker, C. B., J. Am. Chem. Soc. 1990,
4. Noureldin, N. A.; McConnell, W. B.; Lee, D. G., Can. J. Chem. 1984,
112, 5624 and references therein.
62, 2113.
5. Baskaran, S.; Das, J.; Chandrasekaran, S., J. Org. Chem. 1989, 54, 5182.
Donald G. Lee
6. Baskaran, S.; Islam, I.; Vankar, P. S.; Chandrasekaran, S., J. Chem. Soc.,
The University of Regina, Regina, Saskatchewan, Canada
Chem. Commun. 1990, 1670.
A list of General Abbreviations appears on the front Endpapers