A useful diketone, dimedone, can be prepared in high yield by the synthesis shown in Fig. P22.83. Provide structures for both the intermediate A (a Michael-addition product) and dimedone, and give a curved-arrow mechanism for each step up to compound B.

Transcribed Image Text:

CH,(CO,Et)2 + (CH3)C=CH–C—CH, mesityl oxide Figure P22.83 NaOEt EtOH A H₂C- H3C NaOEt EtOH CO₂Et B H3O+ NaOH H₂O H3O+ dimedone