Describe a sequence of reactions by which hept-1-yne can be straightforwardly prepared from hept-1-ene.
O. 1) Br₂2) NaNH₂
O. 1) Br₂; 2) NaNH₂, heat.
O. 1) Br₂; 2) NaOH
O.1) HBr; 2) NaNH₂, heat.