Stereocontrolled total synthesis of (±)-totaryl methyl ether and (±)-semperviryl methyl ether

Article abstract of DOI:10.1016/S0040-4020(01)82004-4

Stereocontrolled synthesis in racemic form of the title diterpene ethers is described. Friedel-Crafts acylation of the naphthalene derivative 15 afforded the methyl ketone 16 in high yield. The compounds 5 and 16 were converted into the hydrophenanthrenones 6 and 7 respectively. Reductive methylation of 6 and 7 in anhydrous ammonia furnished the β, γ-unsaturated ketones 8 and 9 which were stereoselectively transformed into the trans-fused ketones 10 and 11. Huang-Minlon reduction of 10 and 11 afforded the octahydrophenanthrene 27 and (±)-totaryl methyl ether (2) respectively. Friedel-Crafts acylation of 27 provided the methyl ketone 28 which was converted into (±)-semperviryl methyl ether (4).