91Ó°ÊÓ

Is a reagent which is used for the reduction of any compound such as alkenes (double bonds), alkyne, nitro group etc. Hydrogen atoms will attach on both sides of double bond i.e. hydrogenation reaction will take place.

Fig a

When alkenes are treated with bromine the product formed will be 1,2-dibromide or we can say that vicinal-dibromide is produced. For example:

Fig 1[A1]

Product of the reaction (b) is:

figb

${\mathrm{OSO}}_4$is known as osmium tetroxide. It is volatile and is highly toxic in nature. The reaction of alkene in the presence of osmium tetroxide will produce 1,2- diol or vicinal diol. This reaction is known as hydroxylation reaction.

Fig (c)

When alkenes are treated with halogens in water the product formed in that reaction will be halohydrins. In this case our halogen is chlorine therefore, chlorohydrin will be the product. Hydroxide will attach on that carbon atom which is attached to benzene ring and on the other carbon atom chlorine atom will be attached.

Fig d

When alkenes are treated with the reagent $C{H}_2{I}_2,Zn/Cu$the product formed will be cyclopropane ring and this reaction is known as Simmons- smith reaction. The product of reaction (c) is as follows:

Fig e

Reaction of alkene in presence of meta- Chloroperoxybenzoic acid is an oxidation reaction. This reagent is an oxidizing agent. In this reaction insertion of oxygen atom will take place and this reaction is known as Bayer- Villiger Rearrangement reaction. The product of reaction (f) is:

Fig f