[Steenrod]

When cyclohexene is treated with potassium permanganate and sulphuric acid and heated,the product is Hexane-1,6-dioc acid.I am unable to understand how the reaction occurs. Can anyone please explain how it takes place?Thanks.

[discodermolide]

Have a look here:
http://en.wikipedia.org/wiki/Potassium_permanganate

[orgopete]

There are several reagents that act similarly, osmium tetroxide, periodate, and permanganate. You can write a cyclic reaction that is similar to a Diels-Alder reaction when OsO4 reacts with a double bond. The product does not react further. Periodate does not react with an alkene, but it can react with a diol from the osmium reaction to give a similar structure to the osmium intermediate. The difference between these is the periodate structure will undergo a cyclic reversion which cleaves the C-C bond to give two carbonyl groups and reduces the iodine. The osmium intermediate does not cleave the C-C bond and must be hydrolyzed to obtain a diol.

Permanganate will perform both steps if heated. (Cold permanganate can be used to isolate a diol as an alternate to OsO4.) It will add to a double bond as OsO4 does and cleave the C-C bond as periodate does. The product will be two C=O bonds. If these are aldehydes, as they are from cyclohexene, they are also very easily oxidized, and permanganate can also react as an oxidant. It will oxidize the aldehydes to carboxylic acids.