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Please login to access the full content or check if you have access via26.6.5.1.3.1 Variation 1: By Oxidation with Permanganate Salts
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Suffert, J., Science of Synthesis, (2005) 26, 942.
The reduction of potassium permanganate to manganese(IV) oxide in an aqueous medium liberates hydroxide ions,[196] and as a result potassium permanganate mixtures become alkaline when employed as oxidants. When the stability of the substrate is pH dependent this can be a problem, which can be ameliorated when zinc(II) permanganate is used. This compound is conveniently prepared, as the hexahydrate, by the disproportionation of barium manganate in the presence of stoichiometric amounts of sulfuric acid and zinc(II) oxide, followed by filtration through Celite, evaporation of the filtrate, and crystallization from water. Zinc(II) permanganate is considered to be a safe and efficient oxidant, when supported on silica gel; however, when used to oxidize the alkene 234 to the α-hydroxy ketone 235 the yield is poor (36%) (Scheme 105).[196]
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M eeeeeee ee MMeM8 (8.8 e), MeMM8•8M8M (8.8 e), eee M8M (888 μM) ee MM8Me8 (88 eM) eee eeeeeee eeee eeeeeeeeeeee (8.888 e, 8 eeee) ee MM8Me8 (8 eM), eee eeee e-MeMM (8 eM) ee 88°M. Mee eeeeee ee eee eeeeeeee eee eeeeeeeee ee MMM. Meeee 8.8 e, eee eeeeeee eee eeeeeeee eeeeeee e eee ee Meeeee eee eeeeee eeeeeeeeee eeee MM8Me8. Mee eeeeeee eee eeeeeeeeee ee eeeeee ee eee; eeeee: 8.88 e (88%).
References
| [196] | Meeee, M.; Meeeee, M. M., M. Me. Meee. Mee., (8888) 888, 8888. |
| [197] | Meeeeeee, M.; Mee, M.; Meeeeeeeeeeeee, M., M. Mee. Meee., (8888) 88, 8888. |
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- 8.Meeeee-Meee, (8888) 8/8e, 8888.
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