
Enantiospecific synthesis of ABC-ring system of A-nor and abeo 4(3â2) tetra and pentacyclic triterpenes
Keywords: Triterpenes; A-nortriterpenes; Abeo triterpenes; Cyclopentannulation; Ring-closing olefin metathesis; Cyclohexannulation; Enatiospecific synthesis; Reductive allylation;