Search

Asymmetric transfer hydrogenation (ATH) represents a powerful methodology for the\ud synthesis of chiral secondary alcohols. The synthesis of chiral propargylic alcohols by\ud asymmetric transfer hydrogenation of acetylenic ketones has been applied to a number of\ud applications including target oriented synthesis.\ud In this thesis, the asymmetric transfer hydrogenation of a large number of functionalized\ud alkyones and dialkyones has been fully investigated. Basic principles as well as detailed\ud reaction conditions for the ATH of acetylenic ketones have been established. Chiral\ud propargylic alcohols have been successfully prepared by a new method that was\ud developed during this project and some of the products and strategies were used for the\ud total synthesis of (-)-yashabushidiol B and panaxjapyne A.\ud Moreover a group of aromatic ketones functionalized with the 1,3-dioxin-4-one scaffold\ud were prepared and used as substrates for asymmetric transfer hydrogenation. Detailed\ud reaction conditions such as catalyst loading, temperature, substitution effects and stability\ud of substrates were fully investigated. Reduced products were prepared in a highly\ud stereoselective manner and the utility of this method and the resulting chiral alcohols have\ud been illustrated by the total synthesis of yashabushitriol.\ud The application of ATH to the preparation of a highly optically pure ester for scanning\ud tunnelling microscopy (SCM) dissociation and hierarchical assembly was also undertaken.