title: Enantioselective synthesis of a key "A-ring" intermediate for the preparation of 1alpha-fluoro vitamin D3 analogues.
abstract: 1Alpha-fluoro A-ring dienol 2, a useful building block for the preparation of fluorinated vitamin D3 analogues, was synthesized in eight steps from 4-{[tert-butyldimethylsilyl]oxy}cyclohexanone. The most distinctive synthetic development to emerge from this new synthesis is an unprecedented substrate-controlled diastereoselective fluorodesilylation of an advanced dienylsilane intermediate. This is the first enantioselective route to compound 2 relying on the use of an electrophilic fluorinating reagent.
authors.affiliation: University of Oxford, Chemistry Research Laboratory, 12 Mansfield Road, Oxford OX1 3TA, U.K.
authors.forename: Guy
authors.initials: G
authors.lastname: Giuffredi
authors.forename: Carla
authors.initials: C
authors.lastname: Bobbio
authors.forename: Véronique
authors.initials: V
authors.lastname: Gouverneur
mesh_terms: D002762:Cholecalciferol / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry; D008968:Molecular Conformation; D013237:Stereoisomerism
chemical_list: D002762:Cholecalciferol; C019392:1-fluorovitamin D3