title: Simple Designs for the Construction of Complex Trans-Fused Polyether Toxin Frameworks. A Convergent Strategy Based on Hydroxy Ketone Cyclization of C-Linked Oxacycles.
abstract: A single, unified convergent strategy for the stereocontrolled synthesis of trans-fused polyethers was developed. It was demonstrated that the epimerization and reductive intramolecular coupling of hydroxy ketones in reactions with silane-Lewis acids (SI-LA) to generate ethers in C-linked oxacycles is affected by its conformational preference in a predictable manner. The obtained results make evident that the influence of hydrogen bonding between a hemiketal hydroxyl and a 1,3-diaxial C-O bond is regular and predictable and that convergent synthesis of trans-fused polyethers may confidently be conducted on driving ring closure to oxane rings under thermodynamic conditions
authors.affiliation: Centro de Productos Naturales Orgánicos Antonio González, Universidad de La Laguna-CSIC, Carretera de la Esperanza, 2, 38206 La Laguna, Tenerife, Spain.
authors.forename: Eleuterio
authors.initials: E
authors.lastname: Alvarez
authors.forename: Ricardo
authors.initials: R
authors.lastname: Pérez
authors.forename: Milagros
authors.initials: M
authors.lastname: Rico
authors.forename: Rosa M.
authors.initials: RM
authors.lastname: Rodríguez
authors.forename: Julio D.
authors.initials: JD
authors.lastname: Martín