?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.relation=http%3A%2F%2Fd-scholarship-dev.library.pitt.edu%2F8248%2F&rft.title=Studies+on+the+Structure%2FReactivity+Relationships+of+Bicyclic+Epoxonium+Ions+and+Tethered+Nucleophiles.+Efforts+towards+the+Total+Synthesis+of+(%2B)-Lactodehydrothyrsiferol+and+its+Analogs.+Multicomponent+Approach+to+the+Synthesis+of+Oxidized+Amides+through+Nitrile+Hydrozirconation&rft.creator=Wan%2C+Shuangyi&rft.description=A+systematic+study+on+the+structure%2Freactivity+relationships+of+bicyclic+epoxonium+ions+towards+tethered+nucleophiles+has+been+conducted.+The+cyclization+results+show+that+bicyclo%5B3.1.0%5D+epoxonium+ions+have+a+significant+to+exclusive+preference+for+exo-cyclizations+while+bicyclo%5B4.1.0%5D+epoxonium+ions+have+a+strong+preference+for+endo-cyclizations.A+convergent+approach+towards+the+total+synthesis+of+polycyclic+ether+natural+product+(%2B)-lactodehydrothyrsiferol+and+its+analogs+is+currently+being+pursued.+This+route+includes+the+stereoselective+reduction+of+the+bicyclo%5B3.2.1%5D+ketal+which+could+be+prepared+from+coupling+of+the+functionalized+aldehyde+and+vinyl+iodide.+Both+enantiopure+fragments+can+be+obtained+from+cyclizations+of+the+diepoxide+and+the+monoepoxide%2C+respectively.+Key+transformations+involve+two+asymmetric+epoxidations%2C+a+cascade+cyclization+of+diepoxide%2C+a+Cr%2FNi-mediated+coupling+reaction+and+a+stereoselective+reduction+of+bicyclo%5B3.2.1%5D+ketal.An+efficient+one-pot+synthesis+of+oxidized+amides+from+nitrile+hydrozirconation+has+been+developed.+From+the+common+acylimine+intermediates%2C+acyl+aminals+can+be+accessed+through+alcohol+addition%2C+acyl+hemiaminals+can+be+accessed+through+water+addition+and+enamides+can+be+accessed+through+tautomerization.&rft.date=2009-01-29&rft.type=University+of+Pittsburgh+ETD&rft.type=PeerReviewed&rft.format=application%2Fpdf&rft.language=en&rft.identifier=http%3A%2F%2Fd-scholarship-dev.library.pitt.edu%2F8248%2F1%2FETD_WAN2008.pdf&rft.identifier=++Wan%2C+Shuangyi++(2009)+Studies+on+the+Structure%2FReactivity+Relationships+of+Bicyclic+Epoxonium+Ions+and+Tethered+Nucleophiles.+Efforts+towards+the+Total+Synthesis+of+(%2B)-Lactodehydrothyrsiferol+and+its+Analogs.+Multicomponent+Approach+to+the+Synthesis+of+Oxidized+Amides+through+Nitrile+Hydrozirconation.++Doctoral+Dissertation%2C+University+of+Pittsburgh.++++(Unpublished)++