title: Synthesis of the C-1-C-28 ABCD unit of spongistatin 1.
abstract: The synthesis of the C-1-C-28 ABCD fragment of spongistatin is described. Anti-selective boron-mediated aldol coupling of a CD spiroketal ketone fragment to an AB spiroketal aldehyde unit forms the desired C1-C28 advanced intermediate. Other features include the double conjugate addition of a dithiol to an ynone to generate the key beta-keto-dithiane unit required for the synthesis of the AB spiroketal fragment. [reaction: see text]
authors.affiliation: Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Gaunt
authors.forename: Alan S
authors.initials: AS
authors.lastname: Jessiman
authors.forename: Paolo
authors.initials: P
authors.lastname: Orsini
authors.forename: Huw R
authors.initials: HR
authors.lastname: Tanner
authors.forename: David F
authors.initials: DF
authors.lastname: Hook
authors.forename: Steven V
authors.initials: SV
authors.lastname: Ley