Stereoselective Nucleophilic Additions to Aldehydes and Development of New Methodology in Organic Synthesis

Sammanfattning: This thesis is divided into four separate parts with nucleophilic addition to aldehydes as the common feature in three of them.The first part deals with the investigation of the stereochemical induction and elucidation of the factors that dictate the p-facial selectivities in Mukaiyama aldol addition to a- and a,b-heteroatom substituted aldehydes. An explanation for the unexpected shift from 1,2-anti to 1,2-syn selectivity seen in the reaction when applying nucleophiles of different sizes in the addition to a-chloro aldehydes is offered.The next two parts describes the addition of 1,3-bis(silyl)propenes and C3 substituted 1,3-bis(silyl)propenes to aldehydes and the development of two highly stereoselective new methodologies for the construction of 1,3-dienes and 2,3,4,5-tetrasubstituted tetrahydrofuranes, respectively.The last part describes the attempts made towards the total synthesis of (±)-aspidophylline A, where the intention was to apply a domino carbopalladation-carbonylation reaction as the key step in the synthetic route.