Solved: In each reaction box, place the best reagent and conditions
In each reaction box, place the best reagent and conditions from the list below.
Note that the condition of the double bond changed. The moving functionality includes optional addition and elimination reactions.
- When given an alkene: start with the addition
- When given RX or ROH: start with the elimination
Step 1: We’re given an alkene which means the first step should be addition.
We can do hydrohalogenation (which follows Markovnikov’s rule) using HBr.
Step 2: The alkene went from disubstituted to trisubstituted, which corresponds to a Zaitsev elimination. This can be done using a small strong base such as CH3CH2O– (ethoxide ion, an alkoxide).
Therefore, the best reagents and conditions are:
- HBr (hydrohalogenation)
- CH3CH2O– (elimination)