title: One-pot regio- and stereoselective cyclization of 1,2,n-triols.
abstract: A simple and efficient process to cyclize triols containing a 1,2-diol functionality with a pendant hydroxyl group is presented. The one-pot procedure converts the 1,2-diol into an ortho ester in situ, which upon treatment with a Lewis acid generates a cyclic acetoxonium intermediate. This intermediate is subsequently trapped by the pendant hydroxyl group to generate a cyclic ether. The stereochemistry of the 1,2-diol is transferred to the product with complete fidelity (inversion at the site of cyclization), and the reaction proceeds with high regioselectivity. The process is akin to the Lewis acid-catalyzed intramolecular ring-opening of epoxides with hydroxyl groups yielding cyclic ethers of various sizes with regio- and stereochemical control.
authors.affiliation: Department of Chemistry, Michigan State University, East Lansing, MI 48824, USA.
authors.forename: Tao
authors.initials: T
authors.lastname: Zheng
authors.forename: Radha S
authors.initials: RS
authors.lastname: Narayan
authors.forename: Jennifer M
authors.initials: JM
authors.lastname: Schomaker
authors.forename: Babak
authors.initials: B
authors.lastname: Borhan