lemeiux and von rudloff reagents
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Answer:
3.8.4.2.4 Permanganate/periodate
A mixture of potassium permanganate and sodium periodate has also been used to cleave double bonds. This procedure, usually referred to as the Lemieux–von Rudloff reaction,164 can be carried out in several mixed solvent systems such as butanol and water,144 dioxane and water165 or acetone and water.166 It has also been claimed that the addition of phase transfer agents improves yields.167
Table 11. Oxidative Cleavages by Permanganate on Solid Supports.
Substrate Oxidant and conditions Product Yield (%) Ref.
KMnO4,SiO2 (support), benzene
85 162
KMnO4, SiO2 (support), CH2Cl2 or KMnO4, Al2O3 (support), CH2Cl2
50–70 163
KMnO4, SiO2 (support), benzene
84 162
KMnO4, SiO2 (support), benzene
62 162
KMnO4, SiO2 (support), benzene
74 162
In a typical procedure,44 a solution of KMnO4 (7 mg), NaIO4 (225 mg) and K2CO3 (29 mg) in 29 mL of 7:3 t-butyl alcohol/water was added to a solution of alkene (0.213 mmol) in 2 mL of t-butyl alcohol. After 2.5 h the reaction mixture was poured into 50 mL of ether and 30 mL of water acidified to pH 2 with 1 M HCl. The aqueous phase was drawn off and extracted with 50 mL of ether. The combined organic layers were washed with 60 mL of 0.1 M HCl, dried (Na2SO4) and concentrated under reduced pressure to furnish the expected product