C15 FUNCTIONALIZED DERIVATIVES OF ent-KAUR-16-EN-19-OIC ACID: ISOLATION FROM THE SUNFLOWER HELIANTHUS ANNUUS L. AND SYNTHESIS

The known diterpenic ester – 15α-angeloyl-ent-kaur-16-en-19-oic (angeloylgrandifl oric) acid has been isolated from the dry wastes of Helianthus annuus L. The synthesis of 15α-hydroxy- and 15-oxo-ent-kaur-16-en-19- oic acids starting from ent-kaur-16-en-19-oic acid has been performed

A RETRO-BIOMIMETIC ONE-STEP SYNTHESIS OF NATURAL ATISANIC AND BEYERANIC DITERPENOIDS

An efficient retro-biomimetic procedure for the synthesis of two natural products having atisanic and beyeranic structure is reported. The readily available ent-kaurenoic acid is used as the substrate, which provides under superacidic treatment a mixture of natural ent-beyer-15-en-19-oic and ent-atis-16-en-19-oic acids. These compounds have been reported as components of medicinal plants and possess relevant biological activity. Their structure was confirmed on the basis of chemical transformations and spectral data