A concise synthesis and in vitro cytotoxicity of new labdane diterpenes.

A new series of labdane-related diterpenes have been synthesized from (-)-sclareol and assayed in vitro cytotoxicity against mouse and human cancer cells. A key intermediate, homodrimane and furanolabdane derivatives show good in vitro cytotoxicity comparable to those of mitomycin C and adriamycin.