Preparation of intermediates for norlabdane oxide

摘要

The invention concerns a process for preparing (-)-norlabdane oxide from sclareol oxide comprising the steps of: I converting sclareol oxide to 12-acetylnorlabdane oxide by oxidation with an organic hydroperoxide; II converting 12-acetylnorlabdane oxide to 12-acetoxy-norlabdane oxide by oxidation with an organic peracid. Step I is preferably performed with tert-butyl hydroperoxide and step II with peracetic acid. Sclareol oxide may be prepared from sclareol by ozonolysis followed by treatment with alkaline hydrogen peroxide. 12-Acetoxy-norlabdane oxide is preferably converted to norlabdane oxide by reduction with NaBH4 in the presence of a transition metal salt.