Question

how ozonolysis is used to find out position of double bond ?

Answer 1

Ozonolysis is the process by which ozone (O3) reacts with alkenes (olefins) to break the double bond and form two carbonyl groups. If the double bond of the alkene is substituted with hydrogen or carbon atoms, the carbonyl groups that are formed are either aldehydes or ketones. Acyclic alkenes form two carbonyl compounds while cyclic alkenes produce a single compound containing two carbonyl groups. As ananalytical tool, ozonolysis reveals the substitution pattern of a double bond. Acting as a pair of chemical scissors, the reactive gas cuts the double bond and replaces it with oxygen atoms, i. e., carbonyl groups. However, ozonolysis does not afford information on the stereochemistry of the alkene if such stereochemistry existed originally. Thus, the generic, stereoisomeric alkenes 1 and 2 give rise to the same pair of carbonyl compounds. The astute reader will recognize that neither of these reactions is a balanced equation. Only two oxygen atoms (one equivalent of O2) is required to balance this reaction. The fate of the third oxygen atom will be considered later.



Ozonolysis is also an important reaction from the synthetic perspectivewith compounds that have several functional groups. Because alkenes are nucleophilic and carbonyl groups are electrophilic, aldehydes and ketones can be stored as alkenes during synthetic reactions that are electrophilic. At the appropriate time, the alkene can be converted to the aldehyde or ketone when it is its turn to undergo electrophilic reactions.

Answer 2

Ozonylysis is also an important reaction from the synthetic perspective with compound that have several functional groups. Because alkenes are nuleophilic and carbonyl group's are electropholic, aldehydes and ketones can be stored as alkenes during synthetic reactions that are electropholic. As the appropriate time, the alkene can be converted to the aldehydes or ketone when it is its turn to under go electropholic reactions.