%A Binbin Guo
%T Catalytic Asymmetric Bond Constructions in Complex Molecule Synthesis.  An Approach to the Synthesis of Spirolide C and the Development of Enantioselective Enolate Hydroxylation Reactions
%X The asymmetric synthesis of spirolide C, a highly potent marine toxin, has been investigated in our laboratory.  The construction of C7-C28 bis-spiroketal was completed through a strategy utilizing an intermolecular Stetter reaction and a biomimetic ketalization process.  Stereocenters were set in great diastereo- and enantioselectivity via asymmetric catalysis.  The efficiency of the synthesis was demonstrated by its convergency and high yields. 

A cinchona alkaloid catalyzed ketene-oxaziridine cyclocondensation has been developed to provide an access to enantioenriched ?-hydroxy carbonyl compounds.  The oxazolidinones arising from the cyclocondensation were converted to various ?-hydroxy carbonyl compounds via nucleophilic ring openings.  Greater than 98% ee was achieved in oxazolidinone formation and the subsequent ring openings proceeded with retention of the ee or minor epimerization.

%D 2013
%K spirolides, natural product synthesis, asymmetric catalysis, enolate hydroxylation, cinchona alkaloid catalysts, oxaziridines, oxazolidinones, acid chlorides, cyclocondensation 
%I University of Pittsburgh
%L pittir16511