title: Stereocontrolled [4+2]-annulation accessing dihydropyrans: synthesis of the C1a-C10 fragment of kendomycin.
abstract: [reaction: see text] Development of new organosilane reagents bearing C-centered chirality where the stereocenter is fully substituted, and their use in the stereocontrolled synthesis of cis- and trans-dihydropyrans containing a trisubstituted olefin is described. The reagents participate in Lewis acid promoted [4+2]-annulations providing useful levels of selectivity with both aliphatic and aromatic aldehydes. A stereoselective synthesis of the C1a-C10 fragment of kendomycin (1) is also described.
authors.affiliation: Department of Chemistry and Center for Chemical Methodology and Library Development, Metcalf Center for Science and Engineering, 590 Commonwealth Avenue, Boston University, Boston, Massachusetts 02215, USA.
authors.forename: Jason T
authors.initials: JT
authors.lastname: Lowe
authors.forename: James S
authors.initials: JS
authors.lastname: Panek
mesh_terms: D015394:Molecular Structure; D011714:Pyrans / Q000737:chemistry*; D017828:Rifabutin / Q000031:analogs & derivatives* / Q000138:chemical synthesis; D012821:Silanes / Q000138:chemical synthesis / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D011714:Pyrans; D012821:Silanes; C485395:kendomycin; D017828:Rifabutin