title: Novel synthetic approach to 1alpha,25-dihydroxyvitamin D3 and analogues.
abstract: A mild and stereoconvergent synthesis of 1alpha,25-dihydroxyvitamin D(3) (calcitriol, 1a) is described. The key step is a cascade process consisting of two consecutive transformations: An initial palladium-catalyzed 6-exo-cyclocarbopalladation of vinyl triflate 4 followed by a Negishi cross-coupling reaction with alkenyl zinc 3. This approach is of interest for the rapid synthesis of a variety of new vitamin D(3) analogues of therapeutic potential, especially those modified at the triene and ring-A. The mildness of the method also allows the preparation of thermal sensitive vitamin D(3) analogues.
authors.affiliation: Departamento de Química Fundamental, Universidad de A Coruña, E-15071 A Coruña, Spain.
authors.forename: Miguel
authors.initials: M
authors.lastname: Maestro
authors.forename: Clara
authors.initials: C
authors.lastname: Gómez-Reino
authors.forename: Daniel
authors.initials: D
authors.lastname: Nicoletti
authors.forename: Rita
authors.initials: R
authors.lastname: Sigüeiro
authors.forename: Ramón
authors.initials: R
authors.lastname: Fraga
authors.forename: Alberto
authors.initials: A
authors.lastname: Ghini
authors.forename: Mercedes
authors.initials: M
authors.lastname: Torneiro
authors.forename: Antonio
authors.initials: A
authors.lastname: Mouriño
mesh_terms: D015394:Molecular Structure; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry
chemical_list: C118756:dihydroxy-vitamin D3; D014807:Vitamin D