title: Asymmetric synthesis of trans-disubstituted cyclopropanes using phosphine oxides and phosphine boranes.
abstract: The stereocontrolled synthesis of trans-disubstituted cyclopropylketones has been achieved from beta-alkyl, gamma-benzoyl phosphine oxides via a three-step cascade reaction incorporating an acyl transfer, phosphinoyl transfer and cyclisation to form the cyclopropane. Using Evans' chiral oxazolidinone auxiliary and by masking the phosphine oxide moiety as a phosphine borane we have extended the method to the synthesis of enantiomerically-enriched trans-disubstituted cyclopropyl ketones.
authors.affiliation: Cambridge University, University Chemical Laboratory, Lensfield Road, Cambridge, UK CB2 1EW.
authors.forename: Celia
authors.initials: C
authors.lastname: Clarke
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Foussat
authors.forename: David J
authors.initials: DJ
authors.lastname: Fox
authors.forename: Daniel Sejer
authors.initials: DS
authors.lastname: Pedersen
authors.forename: Stuart
authors.initials: S
authors.lastname: Warren
mesh_terms: D001880:Boranes / Q000737:chemistry*; D018360:Crystallography, X-Ray; D003521:Cyclopropanes / Q000138:chemical synthesis* / Q000737:chemistry; D008958:Models, Molecular; D015394:Molecular Structure; D010087:Oxides / Q000737:chemistry*; D010720:Phosphines / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D001880:Boranes; D003521:Cyclopropanes; D010087:Oxides; D010720:Phosphines