Oxidation of Alkenes

[jmarjorie]

Dear All,

 

Apart from KMnO4, can alkaline H2O2 be used to effect oxidation of C=C bond at room temp ?

If yes, what are the ideal reaction conditions,catalysts,yields,precautions ?

Any journal references ?

Thanks in advance,

jmarjorie

[Tartaglia]

Usually H2O2 is used with an OsO4 catalyst to give syn addition of two hydroxyl groups.

It really depends whether you want a 1,2 diol or to cleave the C=C bond. There are many types of oxidation reactions of alkenes using peroxycarboxylic acids, ozone,lead(IV) compound etc,etc. Some are more agressive than others.

Good reference "Advanced Organic Chemistry" Jerry March

[jmarjorie]

Thanks for your reply. I'am interested in achieving a 1,2-diol addition using a catalyst that is cheap and readily available, like lead (IV), (no exotics).

Any journal references ?

jmarjorie

[Tartaglia]

jmarjorie - which alkene are you oxidising?

 

The problem with KMnO4 is that the yield will be low if the alkene has any H substituents (and most do).

 

You should read section 5.6 "Advanced organic chemistry" 3rd Edition Jerry March. There are plenty of references in there.

 

Remember when you use a catalyst you are only using a very small amount. OsO4 may sound exotic to you but it is a standard procedure. Just bear in mind it is volatile and horribly toxic.

 

Lead (IV) acetate will add to acetate groups syn across a double bond which are then easily hydrolysed.

 

There are many methods involving anti addition rather than syn addition. You want to look at the symmetry of the alkene to see whether it matters to you. If anti addition is OK there are a whole host of epoxidation reactions that could be used, which yield 1,2 diols on ring opening hydrolysis

[chuinhen]

The strongest oxidation reagent in organic chemistry context

 

1) acidified KMnO4

2) acidified K2Cr2O7

3) alkaline K2Cr2O7

 

 

The strongest REDUCTION AGENT :

 

1)LiAlH4 lithium aluminium hydride

 

 

 

 

Stick to these reagents . These are the strongest reagents to undergo REDOX reaction .

In addition , u can get the major products that u want by using these reagents .

[Tartaglia]

Chuihen - I've just noticed this. The point here is not to use a strong oxidising agent as that will probably cause oxidation beyond the 1,2 diol required.

Organic chemistry is a subtle and sophisticated science, limiting yourself to the classic schoolboy reagents will not get you very far