title: Reinvestigation of the reactions of camphorketene: structural evidence for pseudopericyclic pathways.
abstract: The stereochemistry of the dimers (3 and 4) of camphorketene (2) have been determined. The crystal structures of 3, 20 and of related compounds show ground-state distortions that are interpreted as prefiguring planar, pseudopericyclic transition states for retro-cycloadditions to form alpha-oxoketenes. The B3LYP/6-31G* optimized geometry for the transition structure (10) for the dimerization of s-Z-formylketene (8) is consistent with this mechanism. Trapping of 2 with alcohols shows selectivity comparable to other alpha-oxoketenes. The lack of reaction of 2 with benzaldehyde and the lack of enol tautomers in camphoric acid derivatives is attributed to angle strain in the bicyclic camphor moiety.
authors.affiliation: Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409-1061, USA.
authors.forename: W W
authors.initials: WW
authors.lastname: Shumway
authors.forename: N K
authors.initials: NK
authors.lastname: Dalley
authors.forename: D M
authors.initials: DM
authors.lastname: Birney