The acetolysis product(s) of the given reaction (solvolysis of the benzylic tosylate in AcOH) is(are)
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Benzylic solvolysis next to an aryl group often proceeds via a \textbf{phenonium} ion; nucleophiles open the bridge \emph{anti}, giving net inversion at that carbon.
Stereocenters not involved in bond making/breaking retain configuration.
When options show pairs, look for “inversion vs retention” at the reacting center to decide.
Step 1: Ionization and anchimeric assistance.
In \(\mathrm{AcOH}\), the benzylic tosylate undergoes solvolysis. Departure of \(\mathrm{OTs^-}\) generates a benzylic cation that is anchimerically assisted by the adjacent phenyl ring to form a bridged \emph{phenonium} intermediate. This “neighboring-group participation” shields one face of the cationic center.
Step 2: Regio-/stereochemical capture.
Nucleophilic attack by \(\ce{AcO^-}\) occurs by \emph{anti} opening of the phenonium bridge at the reacting carbon. Anti opening gives overall inversion at the substitution center (SN2-like outcome), while the other stereocenter—whose bonds are not broken—retains its configuration.
Step 3: Products formed.
Therefore, the acetolysis furnishes the two diastereomers that both reflect \emph{inversion at the reacting center} (attack from the two accessible conformers), corresponding to options (A) and (C). The alternatives (B) and (D) depict retention at the reacting center and are not favored under anchimeric assistance.
\[
\boxed{\text{Anchimeric assistance by Ph }\Rightarrow\ \text{anti attack and inversion at the benzylic center }\Rightarrow\ \text{(A) and (C).}}
\]
