Chemistry Reference
In-Depth Information
oxetane, C. Formation of sodium bromide (NaBr), the salt by-product of this step, is
not shown.
The first step of this reaction is an acid-base proton exchange between a hydroxide
anion (pK
a
of water is approximately 16) and a primary alcohol (pK
a
is approxi-
mately 16) forming the illustrated alkoxide, D. Formation of water, the by-product,
is not shown in this step.
The second step of this reaction is a direct S
N
2 displacement of a bromide anion by
the alkoxide anion present in the same molecule. This step leads to formation of the
oxetane, E. Please note that displacement of the bromide is preferred over displace-
ment of the chloride because bromide is a better leaving group than chloride.
Formation of sodium bromide (NaBr), the salt by-product of this step, is not shown.
This is a solvolysis reaction that proceeds in two steps. The first step involved pro-
tonation of the hydroxy group of p-methoxybenzyl alcohol. Once protonated, a
bromide ion displaces water, generating the illustrated product. The reaction
shown below demonstrates this reaction through an S
N
2 mechanism; however, this
reaction can also be represented through an S
N
1 reaction involving initial
