5
42
I. Mohammadpoor-Baltork et al.
reaction conditions. It is noteworthy that in the absence of montmorillonite K-10,
the reactions are slow and considerable amounts of the starting materials are
recovered unchanged from the reaction mixture. Furthermore, workup of the reac-
tion mixture is rather difficult in this case.
In conclusion, the paper describes a facile and mild procedure for the regen-
eration of aldehydes and ketones from their oximes, semicarbazones, phenylhy-
drazones, and azines. The method offers several advantages including short
reaction times, high yields of the products, cleaner reactions, and a non-toxic
and inexpensive reagent which makes the reaction process convenient, and it is
more economic and environmentally benign.
Experimental
General Procedure for the Conversion of Oximes, Semicarbazones, Phenylhydrazones,
and Azines to their Carbonyl Compounds
A mixture of 1 mmol of substrate, 2 mmol of KMnO and 300 mg of montmorillonite K-10 was ground
4
in a mortar with a pestle for the time specified in Table 1. The progress of the reaction was monitored
by TLC. The mixture was extracted with CH Cl . Evaporation of the solvent followed by chroma-
2
2
tography on silica gel afforded the pure carbonyl compounds in 80–97% yields (Table 1). In the case of
azines 3 mmol of KMnO and 500 mg of montmorillonite K-10 were used.
4
Acknowledgements
We are grateful to the Isfahan and Razi University Research Councils for partial support of this work.
References
[
[
[
[
[
[
[
[
[
1] Greene TW, Wuts PGM (1991) Protective Groups in Organic Synthesis, John Wiley, New York
2] Maloney JR, Lyle RE (1978) Synthesis 212
3] Drabowicz J (1980) Synthesis 125
4] Firouzabadi H, Seddighi M, Arab Ahmadi Z, Sardarian AR (1989) Synth Commun 19: 3385
5] Ranu BC, Sarkar DC (1988) J Org Chem 53: 878
6] Firouzabadi H, Mohammadpoor-Baltork I (1994) Synth Commun 24: 489
7] Ghelfi F, Grandi R, Pagnoni UM (1993) Synth Commun 23: 2279
8] Bandgar BP, Shaikh SI, Iyer S (1996) Synth Commun 26: 1163
9] Mohammadpoor-Baltork I, Pouranshirvani Sh (1996) Synth Commun 26: 1
[
[
[
[
[
[
[
[
10] Varma RS, Meshram HM (1997) Tetrahedron Lett 38: 7973
11] Zhang G-S, Yang D-H, Chen M-F (1998) Synth Commun 28: 3721
12] Hajipour AR, Mahboobkhah N (1998) Synth Commun 28: 3143
13] Jadhav Vk, Wadgaonkar PP, Joshi PL, Salunkhe MM (1999) Synth Commun 29: 1989
14] Mohammadpoor-Baltork I, Hajipour AR, Mohammadi H (1999) J Chem Res 102
15] Hashemi MM, Beni YA (2001) Synth Commun 31: 295
16] Sadeghi MM, Mohammadpoor-Baltork I, Azarm M, Mazidi MR (2001) Synth Commun 31: 435
17] Hajipour AR, Mallakpour SE, Mohammadpoor-Baltork I, Khoee S (2001) Synth Commun 31:
1
187
18] Hajipour AR, Mallakpour SE, Mohammadpoor-Baltork I, Adibi H (2001) Synth Commun 31:
401
19] Shirini F, Zolfigol MA, Mallakpour B, Mallakpour SE, Hajipour AR, Mohammadpoor-Baltork I
2002) Tetrahedron Lett 43: 1555
[
[
3
(