Synthesis of 5-Substituted 4,4-Disubstituted 2-Cyclohexen-1-ones by EG-Base Promoted Michael Addition of 4,4-Disubstituted 2,5-Cyclohexadien-1-ones

Torii, S.; Hayashi, N.; Kuroboshi, M. Synlett 1998, 599.

5-Substituted 4,4-dialkoxy-2-cyclohexen-1-ones were electro-synthesized from 4,4-disubstituted 2,5-cyclohexadien-1-ones, which were obtained from 1,4-dialkoxybenzene derivatives by electrolysis, by EG-base-promoted Michael addition with CH₂E₂ (E = CO₂R, COMe) in moderate to almost quantitative yield. The cyclohexenone derivatives were found to be a good precursor of benzofuranone derivatives through acid-promoted intramolecular lactonization.