Question

For the following reaction only the product shown was formed. Y is more electronegative than X. What can you conclude about the reaction mechanism? anti-Markovnikov anti o anti-Markovnikov syn Markovnikov syn O Markovnikov anti

Answer 1

The above reaction proceeds through the Markonikov's principle and the mode of addition is syn.

According to the Markonikov's principle, the more substituted carbon takes the Nucleophilic part of reagent and less substituted carbon takes the electropositive part of reagent.

Here, the reagent is XY . Y is electronegative. Hence X is partially electropositive.

The double bond of substrate i.e. alkene attracts the positive part of reagent and produces 3°carbocation. The methyl group is being above the plane , the X is attracted from below the plane . As , the carbocatiion is stable , the proceeds for the next step to take the Y(-) i.e. nucleophile from below the plane as above plane is bulkier due to -CH​​​​3 group.

Hence , syn addition takes place.

The mechanism is described below :