Abstract Efficient routes towards the austrodorane skeleton from the labdane diterpene (−)-sclareol (22) are described. The processes, based on pinacol rearrangement, take place with complete diastereoselectivity. Utilizing these, the marine nor-sesquiterpenes (+)-austrodoral (1) and (+)-austrodoric acid (2) have been prepared from 22. Ketone 19, a key intermediate in the synthesis of rearranged cytotoxic