First synthesis of picealactone C. A new route toward taxodione-related terpenoids from abietic acid

A new route to 12-hydroxyabietic acid (10) and related compounds from abietic acid (12), via acetoxyalcohol 15, is reported. Utilizing this, the first synthesis of picealactone C (5) was achieved. The synthesis of natural 12-hydroxydehydroabietic acid (8), 18-hydroxyferruginol (9) and methyl 12α-hydroxyabietate (11) is also reported.