Enantioselective photoelectrocyclization of tropolone derivative in solid state

• Main Author: Wang, Letian
• Format: Others
• Language: English
• Published: 2009
• Online Access: http://hdl.handle.net/2429/10572

Acid 27 and its esters (29 and 21) were prepared, and studies of their photochemical reactivity were investigated in solution. The acid reacts with optical pure amines to form salts whose photoelectrocyclization reactions were studied in solid state. The chiral amines serve as an ionic chiral auxiliary to induce asymmetric synthesis of 32 which could give satisfied enantiomeric excess (up to 79%). The effort has been tried to stop the reaction at the first step that gives only cyclization product. But both compound 29 and 21 gave photorearrangement product 32 and 31. Some other tropolone derivatives with phenyl group also have been synthesized and their photochemical reactions were studied in solution phase. The highlight of the project was to apply the ionic chiral auxiliary method, which was successfully in asymmetric induction in di-π-methane rearrangement reaction and Norrish/Yang type II reaction, to photoelectrocyclization reaction. === Science, Faculty of === Chemistry, Department of === Graduate