Q8-3P. - Organic Chemistry (Mcmurry)

Question

Question: What product would you expect to obtain from addition of   to 1,2-dimethyl-cyclohexene? Show the stereochemistry of the product.

Step-by-Step Solution

Answer

Answer

The product obtained is,

Step 1: Halogenation of alkene

In the halogenation of alkene, bromine and chlorine adds rapidly and give 1,2-dihalides. When halogenations occur in cycloalkene, only trans stereoisomers are formed by dihalide addition.

Step 2: The product obtained from the addition of Cl 2 to 1, 2-dimethyl-cyclohexene

The addition of ${\mathrm{Cl}}_2$to a cycloalkene takes place by the electrophilic addition of ${\mathrm{Cl}}^{+}$to the alkene, forming a carbocation intermediate. On further reaction with ${\mathrm{Cl}}^{-}$, dichloride addition product is obtained. The chlorines are tans to one another like methyl groups.

              Formation of product from the addition of ${\mathrm{Cl}}_2$to 1,2-dimethyl-cyclohexene