title: A cyclopropane fragmentation approach to heterocycle assembly: a convergent synthesis of oxepanes.
abstract: [reaction: see text] A cyclopropanol fragmentation approach to the synthesis of oxepanes has been developed. This convergent strategy condenses cyclopropyl diols with aldehydes to form an acetal, which is subsequently rearranged to furnish a keto-oxepane. The reaction has been developed as a one-pot procedure, utilizing sequential addition of Al(OTf)3 and TiCl4. Yields range from 50 to 70% for the sequence. A Zimmerman-Traxler transition state disposing substituents in equatorial positions is consistent with the observed formation of strictly cis products.
authors.affiliation: Department of Chemistry, James Madison University, Harrisonburg, VA 22807, USA.
authors.forename: Kerry E
authors.initials: KE
authors.lastname: O'Neil
authors.forename: Seth V
authors.initials: SV
authors.lastname: Kingree
authors.forename: Kevin P C
authors.initials: KP
authors.lastname: Minbiole