Russian Journal of Organic Chemistry, Vol. 41, No. 3, 2005, pp. 390–392. From Zhurnal Organicheskoi Khimii, Vol. 41, No. 3, 2005, pp. 400–402.
Original English Text Copyright © 2005 by Shirini, Dabiri, Dezyani, Jalili.
Polymer-Supported Reagents.
Mild and Efficient Method of Oxidation of Alcohols*
1
2
2
3
F. Shirini , M. Dabiri , S. Dezyani , and F. Jalili
1
Department of Chemistry, Faculty of Science, Guilan University, P.O. Box 1914, Rasht, 41355 Iran
e-mail: shirini@guilan.ac.ir
2
Department of Chemistry, Shahid Beheshti University, Tehran, Iran
3
Merck Trading, P.O. Box 15745-653, Tehran, Iran
Received December 22, 2003
Abstract—A mild and efficient procedure has been proposed for the oxidation of alcohols to the corresponding
carbonyl compounds using quaternary ammonium Dowex 1-X8 resin in which chloride ions have been
–
4
replaced by permanganate ions MnO
(DMn).
Although numerous methods for the oxidation of
alcohols to the corresponding carbonyl compounds are
known [1–6], in the general case the problem cannot
be regarded as solved completely. The main disadvan-
tages of the known procedures include difficulties in
the preparation of necessary reagents and treatment
of reaction mixtures. Insoluble polymer-supported
reagents are convenient from the practical viewpoint
for solving many problems in organic synthesis [7–9].
A polymeric support provides a specific reaction
medium which favors enhanced reactivity of a number
of reagents and facilitates treatment of reaction mix-
tures: the products can readily be isolated by simple
filtration. For example, anion exchangers were
successfully used in the C-alkylation of phenols [10],
O-alkylation of carboxylate ions [11], and synthesis of
alkyl and aralkyl fluorides [12]. Polymeric thioanisole
was shown to be effective [13] in the Corey oxidation
of alcohols [14]. The efficiency of polymer-supported
reagents was demonstrated using fairly sensitive com-
pounds as substrates, in particular in the oxidation of
some intermediate products in the synthesis of pros-
taglandins [13]. However, the entire procedure was
fairly laborious, and specially prepared polymers were
required.
was added under stirring to a solution of 3 mmol of
KMnO in 40 ml of water. After 3 h, chloride ions
4
–
4
were completely replaced by MnO . The product was
washed in succession with water and acetone and dried
for 15 min at 50°C under reduced pressure. The IR
spectrum of the modified resin contained the following
–
1
–
absorption bands, ν, cm : 725 w, 900 m (MnO ),
4
1036 w, 1063 m, 1112 m, 1622 s, 1789 m [15]. In
order to determine the capacity, a mixture of 0.5 g of
the modified resin and 30 ml of 2 N H SO was stirred
2
4
for 1 h. A known excess of a standard More salt solu-
tion was added, and the mixture was stirred until the
dark resin color disappeared completely. The unreacted
More salt was titrated using a standard solution of
potassium permanganate, and permanganate equivalent
–
of the obtained Dowex 1-X8/MnO (DMn) was calcu-
4
–
4
lated (0.6 mmol of MnO per gram of the resin).
The polymer-supported reagent showed a high
efficiency in the oxidation of alcohols to the corre-
sponding carbonyl compounds which were formed in
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0–95% yield (see table). The oxidation procedure was
as follows: a mixture of 1 mmol of alcohol and 5 mmol
DMn (taking into account its capacity) in 10 ml of
acetonitrile was heated under reflux with stirring over
a period indicated in table. The mixture was filtered to
remove the resin, and the product was isolated by
evaporation of the filtrate. In all cases, the products
contained neither traces of the corresponding acids nor
other impurities. In some cases, the reaction was not
complete, and a part of the initial alcohol was
recovered from the reaction mixture. The resulting
carbonyl compounds were identified by comparing
In the present communication we report on a simple
preparation of a convenient polymeric reagent for
oxidation of alcohols on the basis of commercially
available anion exchanger. The oxidant was obtained
–
as follows: 5 g of Dowex 1-X8 (Cl form, 20–50 mesh)
*
The original article was submitted in English.
070-4280/05/4103-0390 © 2005 Pleiades Publishing, Inc.
1
Shirini
