The Total Synthesis of (±)-Taxodione, A Tumor Inhibitor

A total synthesis of (±)-taxodione (I) has been achieved. The Friedel and Crafts reaction of 1,2-dimethoxy-3-isopropylbenzene (IV) with succinic anhydride gave β-(4-hydroxy-3-isopropyl-5-methoxybenzoyl)propionic acid (V), which was then converted to γ-(4,5-dimethoxy-3-isopropylphenyl)butyric acid (IX). Since the cyclization of IX gave 6,7-dimethoxy-8-isopropyl-1-tetralone (X), the acid (IX) was subjected to bromination, cyclization, and then debromination. Subsequently, 7,8-dimethoxy-6-isopropyl-1-tetralone (XIII) was converted to (±)-7,8-dimethoxy-6-isopropyl-1-methyl-2-tetralone (XV). The condensation of (±)-XV with the methyl vinyl ketone gave a (±)-hexahydro-2-oxo-phenanthrene derivative (XVI), which was then further converted to (±)-11,12-dimethoxyabieta-5,8,11,13-tetraene (XIX). The introduction of a carbonyl group at the 6 position was achieved by the hydroboration of (±)-XIX, followed by the oxidation of the resulting 6-hydroxyl derivative. Finally, (±)-11,12-dimethoxyabieta-8,11,13-trien-6-one (X...