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Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: tomaszp on May 23, 2013, 07:15:41 AM

Title: Oxidation of alkenes with potassium permanganate and osmium tetroxide
Post by: tomaszp on May 23, 2013, 07:15:41 AM
Hello!
I'm from Poland, so I'm so sorry about my language errors.
But I've got a question for you: please give me a mechanism of oxidation of alkanes with potassium permanganate and osmium tetroxide. I've got a problem with that, cuz in books ther's only KMnO4, oraz OsO4 up on the arrow, and ther's no detailed mechanism of this reaction. I'v got a problem, cuz I need mechanism of alkenes oxidation with potassium permangate in alkaline reaction medium, and with oxitation by osmium tetroxide ther's also sodium bisulfite, and I haven't got any idea for what is that reagent.
I would be very happy if someone gave me the reaction mechanism and explained  me what is sodium bisulfate for.
Title: Re: Oxidation of alkenes with potassium permanganate and osmium tetroxide
Post by: Hunter2 on May 23, 2013, 07:27:01 AM
http://www.grossmont.edu/martinlarter/Chemistry%20231/Reference/Alkenes7_oxidation_given_Lecture21%5B1%5D.pdf

Check page 8 and following.
Title: Re: Oxidation of alkenes with potassium permanganate and osmium tetroxide
Post by: tomaszp on May 23, 2013, 07:30:11 AM
thank you very very much
greetings!
Title: Re: Oxidation of alkenes with potassium permanganate and osmium tetroxide
Post by: tomaszp on May 23, 2013, 07:52:28 AM
But still I don't know for what is sodium bisulfate
Title: Re: Oxidation of alkenes with potassium permanganate and osmium tetroxide
Post by: Hunter2 on May 23, 2013, 09:42:44 AM
In which step it wii be added. Its a reducer to reduce the excesss permanganate
Title: Re: Oxidation of alkenes with potassium permanganate and osmium tetroxide
Post by: tomaszp on May 23, 2013, 10:36:15 AM
Probably I didn't wrote it- sodium bisulfate is in mechanism with OsO4, and it's up on the arrow after formation of the intermediate product when the osmium compound is attached to a double bond with oxygen atoms.
Title: Re: Oxidation of alkenes with potassium permanganate and osmium tetroxide
Post by: orgopete on May 23, 2013, 03:06:49 PM
Quote from: tomaszp on May 23, 2013, 10:36:15 AM
Probably I didn't wrote it- sodium bisulfate is in mechanism with OsO4, and it's up on the arrow after formation of the intermediate product when the osmium compound is attached to a double bond with oxygen atoms.

I am hoping someone can help me out here. It isn't bisulfate, but bisilfite that is used, Na2SO3 or NaHSO3. Those reagents are used to convert insoluble manganese to soluble manganese salts.

It is also used with osmium tetroxide to regenerate it and make the reaction catalytic in osmium. I am more familiar with other oxidants being used. I don't know why it, which seems to be a reductant is used, except that it is.
Title: Re: Oxidation of alkenes with potassium permanganate and osmium tetroxide
Post by: tomaszp on May 23, 2013, 03:22:52 PM
damn. I'm so sorry for misleading. like I said I'm from Poland I'm starting with chemical English. yeah it's definitly NaHSO3, not NaHSO4. orgopete- you said, that you knew other oxidants which are more familiar... may I ask you what are those oxidants, and if you would be so kind as to give me some mechanisms examples.
Thank you for the anserw ;)
Title: Re: Oxidation of alkenes with potassium permanganate and osmium tetroxide
Post by: orgopete on May 23, 2013, 04:31:15 PM
Hydrogen peroxide, t-butyl peroxide, and N-methylmorpholine-N-oxide