Quiz - Reactions of Alkenes - 2 | Reactions of Alkenes
Organic Chemistry 2 - Quiz - Reactions of Alkenes - 2
Following Markovnikov's rule, what is the major product of hydrohalogenation of propene with HBr?
Markovnikov's rule states that in addition reactions of HX to alkenes, the hydrogen atom attaches to the less substituted carbon, resulting in the formation of the most stable carbocation (most substituted carbocation). Thus, the major product of the reaction between propene and HBr is 2-bromopropane.
Which of the following describes the outcome after hydration of an alkene using the oxymercuration-demercuration method?
The oxymercuration-demercuration method results in the Markovnikov addition of water to an alkene, and this method avoids carbocation rearrangement that can lead to other products.
What is the stereochemical outcome when an alkene undergoes halogenation with Br2?
Halogenation of alkenes with diatomic halogens such as Br2 typically proceeds with anti addition, resulting in trans products.
What is the result of the hydroboration-oxidation of an alkene?
Hydroboration-oxidation leads to the anti-Markovnikov addition of OH across the double bond, adding the OH group to the less substituted carbon atom.
How does the anti dihydroxylation of alkenes using MCPBA differ from syn dihydroxylation?
Anti dihydroxylation with MCPBA leads to the trans-diol due to the intermediate formation of an epoxide, which opens up to give the trans product, whereas syn dihydroxylation typically uses osmium tetroxide or potassium permanganate to yield cis-diols.
Which reaction is ideal for achieving high stereocontrol in the formation of bromohydrins from alkenes?
Halohydrin formation using Br2 and water provides high stereocontrol, leading to bromohydrin through a halonium ion intermediate that is opened by water to give high anti-addition selectivity.
During radical bromination of alkenes, which position is most likely to be brominated?
Radical bromination favors the formation of the most stable radical intermediate, which is most often the allylic position, due to resonance stabilization of the radical.
In the context of alkene reactivity, how does the steric bulk of substituents affect reactions like hydrohalogenation and halohydrin formation?
Increased steric bulk around the double bond can slow down reactions like hydrohalogenation and halohydrin formation and can influence the regioselectivity by favoring the addition of reagents to the less hindered side.