5, 8, 11, 13-Abietatetraen-3-one (3) and its 12-methoxy derivative (7) were oxidized to the corresponding 3, 7-diones, which were rearranged respectively into 2-isopropyl-6-methyl-5-(4-methyl-3-oxopentyl)naphthalene (6) and its 12-methoxy derivative (10) by sodium borohydride reduction and subsequent dehydration with boron trifluoride etherate. Compound 10 was further converted into 3-oxosapriparaquinone (1) via 5-(3-acetoxy-4-methylpentyl)-2-isopropyl-6-methyl-3, 4-naphthoquinone (14).