From the aerial parts of Salvia occidentalis (Labiatae) a new diterpenoid with a rearranged neo-clerodane skeleton was isolated. This new compound was named salvioccidentalin and its structure was established by spectroscopic means. A probable biogenetic relationship with salvigenolide from S. fulgens and salvileucalin A and spiroleucantholide from Salvia leucantha is proposed.

Ring functionalization: the total synthesis of a natural derivative of (-)-13-oxyingenol, a potent anti-HIV diterpenoid, is reported. The key steps in this synthesis include a ring-closing olefin metathesis and a Mislow-Evans-type [2,3]-sigmatropic rearrangement. This synthesis provides access to (-)-13-oxyingenol and its natural derivative in 21 steps from a synthetic intermediate previously p...

The highly diastereoselective cascade sequence of three successive thermal pericyclic reactions of 1,2-divinylcyclohexanol allyl and propargyl ethers is described. This novel tandem process provides an efficient synthesis of sesqui- and diterpenoid skeletons having a quaternary carbon at C9. [reaction: see text]

The title compound, C(24)H(34)O(8), a natural ent-kaurane diterpenoid, is composed of four rings with the expected cis and trans junctions. The crystal structure is stabilized by inter-molecular O-H⋯O hydrogen bonds. In addition, an intra-molecular O-H⋯O hydrogen bond occurs.

The absolute configuration of the diterpenoid 9,12-cyclomulin-13-ol (1), a constituent of Azorella and Laretia species, has been established by vibrational circular dichroism spectroscopy in combination with density functional theory calculations. The obtained normal diterpene absolute configuration confirms that of azorellanol (2), which was determined by single crystal X-ray diffraction.