The negatively charged oxygen compound
is the electron donor and is either a nucleophile or base.
The alkyl halide is the electrophile or electron acceptor
The electrophilic carbon is tertiary
The electron donor, t-butoxide is a bulky sterically hindered strong base
that is a very poor nucleophile
The solvent tertiary-butanol.
However, the formation of a carbocation is not likely
since a strong base is present and a fast exothermic E2 reaction
will dominate over a slow endothermic SN1/E1 reaction
Looking at the substitution/elimination chart for alkyl halides
We see t-butoxide is a poor nucleophile and a bulky sterically hindered strong base
that is attacking a sterically hindered tertiary alkyl halide.
An E2 reaction will occur
The dominate reaction will be an E2 reaction because
the bulky base is sterically hindered from reaching the electrophilic carbon.
The SN2 product will not form in this reaction.
The E2 reaction can occur with the at secondary beta carbon
to product 2-methylbut-2-ene
or at the primary beta carbon to produce 2- methylbut-1-ene
Looking at the reaction coordinate potential energy diagram
we see that there is greater steric interaction between the base and the substrate in the transition state
when the bulky base is abstracting a secondary proton
compared with abstracting a primary proton.
The energy of the transition state
that produces the more thermodynamically stable alkene
is greater than the transition state that produces the less stable alkene.
A larger activation energy decreases the rate of reaction
and causes the more stable alkene to become a minor product.
Thus, the major product of this reaction is the less stable alkene 2-methylbut-1-ene
or the Hofmann product.