Please use this identifier to cite or link to this item: http://scholarbank.nus.edu.sg/handle/10635/30692
Title: Part A: Synthesis of mannoside glycans of phosphatidylinositol mannosides (PIMs) Part B: Synthetic Studies towards Bielschowskysin Macrocycles
Authors: RAVI KUMAR SRIRAMULA
Keywords: Phosphatidylinositol Mannosides (PIMs), In situ glycosylation, Bielschowskysin, Allene, Butenolide, Transannular [2+2] cycloaddition, RCM.
Issue Date: 19-Jan-2011
Source: RAVI KUMAR SRIRAMULA (2011-01-19). Part A: Synthesis of mannoside glycans of phosphatidylinositol mannosides (PIMs) Part B: Synthetic Studies towards Bielschowskysin Macrocycles. ScholarBank@NUS Repository.
Abstract: The first part of my Ph.D. research concentrates on the synthesis of the mannoside glycan portion of phosphatidylinositol mannosides (PIMs). A newly reported in situ glycosylation of Seeberger with 1,2-orthoesters was adopted towards a linear synthesis of the glycan portion. This linear synthesis enabled the synthesis of a series of PIM-1, PIM-2, PIM-3, PIM-4, PIM-5 and PIM-6 mannoside glycans. The major part of my research work focused on transannular driven synthetic studies towards the total synthesis of bielschowskysin, a highly oxygenated, hexacyclic fused cembrane diterpene. Our initial efforts were focused on a transannular [2+2] model macrocycle of bielschowskysin encompassing the butenolide and allene functionalities and a 15- membered macrolactone was achieved via Yamaguchi macrolactonization. The synthetic studies towards total synthesis of bielschowskysin were engaged based transannulation strategy. A LiAlH4 mediated reductive formation of a highly functonalized allene was achieved. A RCM macrocyclization strategy was studied to construct the 14 membered macrocycle of the bielschowskysin carbon framework. The major part of my research work focused on transannular driven synthetic studies towards the total synthesis of bielschowskysin, a highly oxygenated, hexacyclic fused cembrane diterpene. Our initial efforts were focused on a transannular [2+2] model macrocycle of bielschowskysin encompassing the butenolide and allene functionalities and a 15- membered macrolactone was achieved via Yamaguchi macrolactonization. The synthetic studies towards total synthesis of bielschowskysin were engaged based transannulation strategy. A LiAlH4 mediated reductive formation of a highly functonalized allene was achieved. A RCM macrocyclization strategy was studied to construct the 14 membered macrocycle of the bielschowskysin carbon framework. The major part of my research work focused on transannular driven synthetic studies towards the total synthesis of bielschowskysin, a highly oxygenated, hexacyclic fused cembrane diterpene. Our initial efforts were focused on a transannular [2+2] model macrocycle of bielschowskysin encompassing the butenolide and allene functionalities and a 15- membered macrolactone was achieved via Yamaguchi macrolactonization. The synthetic studies towards total synthesis of bielschowskysin were engaged based transannulation strategy. A LiAlH4 mediated reductive formation of a highly functonalized allene was achieved. A RCM macrocyclization strategy was studied to construct the 14 membered macrocycle of the bielschowskysin carbon framework.
URI: http://scholarbank.nus.edu.sg/handle/10635/30692
Appears in Collections:Ph.D Theses (Open)

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