title: Pyran annulation: asymmetric synthesis of 2,6-disubstituted-4-methylene tetrahydropyrans.
abstract: [reaction: see text] A reaction process for the asymmetric construction of a variety of cis or trans disubstituted pyrans is described. This sequences allows for the asymmetric convergent union of two aldehydes with silyl-stannane reagent 1 in a two-step process: catalytic asymmetric allylation of the first aldehyde using 1 with a BITIP catalyst, followed by reaction of the alcohol so obtained with a second aldehyde and TMSOTf.
authors.affiliation: Department of Chemistry, University of Utah, Salt Lake City, Utah 84112, USA. keck@chemistry.utah.edu
authors.forename: Gary E
authors.initials: GE
authors.lastname: Keck
authors.forename: Jonathan A
authors.initials: JA
authors.lastname: Covel
authors.forename: Tobias
authors.initials: T
authors.lastname: Schiff
authors.forename: Tao
authors.initials: T
authors.lastname: Yu
mesh_terms: D007202:Indicators and Reagents; D011714:Pyrans / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D007202:Indicators and Reagents; D011714:Pyrans