MolSynapsequestion bank

MolSynapse / Question bank / Organic Reaction Mechanisms II: Electrophilic and Radical Reactions / Anti-Markovnikov addition of HBr

JEE Advanced levelSingle correct optionDifficulty 3 of 3o2102

Propene is treated with HBr in the presence of peroxide to give X. X is converted to the Grignard reagent Y with Mg in dry ether, and Y is then treated with $D X_{2} O$ . The final organic product is

A $CH X_{3} CH X_{2} CH X_{2} OD$
B $CH X_{3} CH X_{2} CH X_{2} D$
C $CH X_{3} CHDCH X_{3}$
D $CH X_{3} CHBrCH X_{3}$

Answer: B

Peroxide-promoted addition gives X = 1-bromopropane. Mg converts it to

CH X_{3} CH X_{2} CH X_{2} MgBr

(Y), whose carbon is deuterated by

D X_{2} O

to give

CH X_{3} CH X_{2} CH X_{2} D

(1-deuteropropane). If the Markovnikov bromide had formed,

CH X_{3} CHDCH X_{3}

would result.

Practice Organic Reaction Mechanisms II: Electrophilic and Radical Reactions More on Anti-Markovnikov addition of HBr

Previous questionNext question

More questions on Anti-Markovnikov addition of HBr