title: Stereoretentive O-to-C rearrangement of vinyl acetals: solvent cage effects as a stereocontrol element.
abstract: The Lewis acid-mediated rearrangement of chiral vinyl acetals may be induced to provide the product of stereoretention using Me3Al and BF3.OEt2 in concert. The selectivities obtained in this reaction (86:14 to 96:4) are complementary to that observed when relying on oxocarbenium facial bias to control the newly formed stereocenter. Evidence is presented that this reaction occurs by tight ion-pair binding in the solvent cage. The relay of C-O bond stereochemistry to a C-C bond stereocenter via ionic intermediates is an addition to similar established methods such as the Claisen rearrangement.
authors.affiliation: Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, USA.
authors.forename: Yongda
authors.initials: Y
authors.lastname: Zhang
authors.forename: Nathan T
authors.initials: NT
authors.lastname: Reynolds
authors.forename: Kavita
authors.initials: K
authors.lastname: Manju
authors.forename: Tomislav
authors.initials: T
authors.lastname: Rovis
mesh_terms: D000080:Acetals / Q000737:chemistry*; D004988:Ethers, Cyclic / Q000737:chemistry; D012997:Solvents / Q000737:chemistry; D013237:Stereoisomerism; D014753:Vinyl Compounds / Q000737:chemistry*
chemical_list: D000080:Acetals; D004988:Ethers, Cyclic; D012997:Solvents; D014753:Vinyl Compounds