Asymmetric Synthetic Studies Towards Malabanone A And Visible-Light Promoted Synthesis Of 2,4-Disubstituted 1,3,5-Triazines

In this thesis,we mainly focused on the asymmetric synthetic studies towards antimalaria natural nortriterpenoid malabanone A.A visible-light promoted “green” synthesis of 2,4-disubstituted 1,3,5-triazines was also designed and performed.The thesis mainly includes the following three chapters: Chapter 1: The application of(R)-or(S)-carvone as a chiral pool in the total synthesis of natural terpenoids(review)In this chapter,the recent applications of(R)-or(S)-carvone as a chiral starting material in the total synthesis of natural terpenoids were reviewed.Chapter 2: Asymmetric synthetic studies toward Malabanone AIn this chapter,the 6/6/6 tricyclic skeleton of norterpenoid malabanone A was achieved from(R)-carvone via intramolecular 1,3-dipolar cycloaddition and a Diels-Alder cycloaddition reaction.And the construction of the requisite cyclopentenone motif(D ring)was also investigated relying on the Nazarov cyclization reaction.Meanwhile,the formal synthesis of pyripyropene A was achieved through advanced intermediates via several simple transformations.Chapter 3: Visible-light promoted synthesis of 2,4-disubstituted 1,3,5-triazinesIn this chapter,we briefly described the importance of triazines compounds in pharmaceutical chemistry.Then we designed a new method to prepare substituted triazines via the visible-light promoted radical addition-cyclization reaction and the preliminary reaction conditions and the scopes of substrates were screened.