A Synthetic Approach to (±)-Tridentoquinone

Synthesis of the ansa-bridged benzofuranquinone (±)- tridentoquinone (±)-(1) is approached by construction of a C₄ methyl ketone chain at the 3-position of 6-bromo-4, 5, 7-trimethoxy-2, 2-dimethyl-2, 3-dihydrobenzofuran (10) and alkylation at its 6-position leading after modification to a dimethyl C₁₀ aldehydic chain. Closure of the ansa bridge by McMurry coupling of the aldehyde and ketone groups of the intermediate (33) with C₈K/TiCl₃ appears to occur, but in poor yield and with uncertain stereochemistry, and the synthesis has not been completed.