Question

identify the reagents needed to best achieve the following transformations.
rxn i
rxn ii
a. hbr, roor 1. bh₃, thf 2. h₂o₂, oh⁻
b. hbr, roor h⁺, h₂o
c. hbr 1. bh₃, thf 2. h₂o₂, oh⁻
d. hbr h⁺, h₂o

Explanation:

• For reaction I (addition of \(Br\) to alkene): In the presence of peroxides (\(ROOR\)), \(HBr\) adds to the alkene in an anti - Markovnikov fashion (peroxide effect). Without peroxides, \(HBr\) would add in a Markovnikov fashion. So, \(HBr\) with \(ROOR\) is needed for anti - Markovnikov addition of \(Br\) as shown in reaction I.
• For reaction II (addition of \(OH\) to alkene): Hydroboration - oxidation (\(BH_3/THF\) followed by \(H_2O_2/OH^-\)) gives anti - Markovnikov addition of \(OH\) to the alkene. Acid - catalyzed hydration (\(H^+/H_2O\)) gives Markovnikov addition of \(OH\).

Answer:

A. \(HBr, ROOR\) for \(Rxn\ I\) and \(1. BH_3, THF; 2. H_2O_2, OH^-\) for \(Rxn\ II\)