Synthesis And Transformations Of 2,3-Secotriterpene Derivatives Of Betulin
Pentacyclic triterpenoids of natural and semisynthetic origin are characterized by their high biological activity as a result of the fact that these compounds can be obtained from readily available sources. Typical representatives of this group of triterpenoids are betulin, a major component of birch bark Betula, and its derivatives betulinic and betulonic acids. This chapter explores the obtained results of own researches on the synthesis and chemical modification of 2,3-seco- triterpene compounds that resulted to a wide spectrum of linear and cyclic heteroatom 2,3-secotriterpene derivatives. Synthetic transformations of betulinic and betulonic acids relate mainly to modifications at the C-3 and C-28 atoms. Assessment of the antiviral activity of the 2,3-secoamides showed that introducing pharmacophore groups into the C-3 and/or C-28 position of the carbon skeleton of A-secotriterpenoids could produce compounds with high antiherpes activity.