Summary of Enolate Syntheses

Retrosynthesis b is preferred since it has a more stable enolate nucleophile containing two EWGs. Such a stabilized enolate is required for the Michael reaction. In addition, retrosynthesis b results in simpler starting materials that are more nearly equal in size. 

The synthesis of the TM involves simply mixing the starting materials together with sodium ethoxide in ethanol (note that the alkoxide base is chosen to match the ester leaving group). Recall that an a,P-unsaturated compound such as phenyl vinyl ketone can be prepared via the Mannich reaction. 

When the target molecule has a carbonyl, always look to the alpha carbon for a potential disconnection site. The enolate nucleophile (alpha carbon) can react with a variety of electrophiles (ketone, aldehyde, ester, or a,P-unsaturated C=0) to give a variety of functional group patterns. 

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