Non-stereoselective Synthesis of Sertraline

In the synthetic direction, coupling of the dichlorobenzene unit to a-naphthol emerges immediately as a key synthetic issue and is discussed in the next example. 

Example 9.5 Consider synthetic routes to TM 9.3 neglecting any stereochemical aspect of the synthetic steps. 

Regioselective electrophilic attack of the vinylogous acyl cation in the AICI3 complex on 1,2-dichlorobenzene affords TM 9.3a controlled by steric perturbation at both ortho positions to chlorine atoms. 

Note The vinylogy rule states that in a,P-unsaturated carbonyl compounds, and generally in alkenes with EWG at the a-C atom, the H atom in the y position (II) exhibits similar acidity as in the a position (I) to the carbonyl group (Fig. 9.2). 

This rule can be extended to other conjugated systems and applied to the reactivity of other groups in the vinylogous position to the EWG group. 

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