%A Jeremy M Raelin
%T Extension of ketene-mediated asymmetric methodology
%X Ketenes are molecules containing a carbonyl group connected to an alkylidene group by way of a double bond (a pi-bond). The electrophilic nature of ketenes at their center, sp-hybridized carbon atom is the origin of many of the chemical transformations availible to these molecules. Previously in the Nelson laboratory, ketenes had been successfully employed in the acyl halide-aldehyde cyclocondensation (AAC) reaction. Both Lewis acid- and Lewis base-catalyzed AAC processes provide access to optically active 3,4-disubstituted-syn-2-oxetanones. The work described herein employs ketene in the Lewis base-catalyzed AAC reaction in an attempt to improve and expand the general utility of this reaction technology. This improved AAC methodology was then applied in the total synthesis of the natural product motuporin. Ketene was subsequently employed in the development of a novel ketene-Claisen rearrangement.
%D 2006
%K 2-oxetanone; AAC; acyl-halide aldehyde cyclocondensation; beta-lactone; Claisen; ester enolate Claisen; ketene; lactone; motuporin
%I University of Pittsburgh
%L pittir9913