91Ó°ÊÓ

In the first reaction reagent is bromine, and the reactant is cholesterol. In cholesterol, an alkene is a nucleophile, and it is reactive; therefore, double bonds of an alkene will react with the bromine and will for vicinal- dibromide or 1,2- dibromide.

In this reaction, the reactant is an unsymmetrical alkene. When treated with the reagent HBr, it will follow Markovnikov’s rule, and a hydrogen atom and bromine will attach on both sides of the double bond. According to Markovnikov’s rule, a hydrogen atom will attach to the carbon atom having more hydrogens, and bromine will attach to that carbon atom which is having less number of hydrogen atoms.

Hence, the product of the reaction is:

In this reaction, the reagent is osmium Tetraoxide, also known as osmic acid. When cholesterol is treated with this reagent, double bonds of reactant will react with the reagent and produce 1,2-diol.

When the reactant cholesterol is treated with the reagent, the double bond of the reactant will react with the reagent. This reaction is a hydroboration- oxidation reaction, and a hydrogen atom and hydroxide will add to both sides of the double bond according to anti- Markovnikov’s rule.

When our reactant, i.e., cholesterol, is reacted with the reagent, the alkene bond will be converted into a cyclopropane ring, and this reaction is known as Simmons- Smith reaction.

Hence, the product of the reaction is: