Abstract
(-) -Ambrox (1) and (+) -8-demethylisoambrox (2), which give out a strong ambergris-type odor, were efficiently synthesized from (-) -levopimaric acid (3). The keto diester (8) was obtained by ozonolysis of methyl levopimalate. By the Wittig reaction, followed by epoxidation and reduction, the methyl and hydroxyl groups at C-8 were introduced. The triol (15) was convefted to the 8 α, 12-epoxy mesylate (16) by dehydration with methanesulfonyl chloride. The reduction of 16 with sodium iodide and zinc dust gave (-) -ambrox (1).