title: Synthesis of new 18-substituted analogues of calcitriol using a photochemical remote functionalization.
abstract: A novel convergent synthetic approach to new analogues of calcitriol modified at the C-18 position is reported. The key step in the synthesis is the 20-hydroxyl-directed photochemical iodination of the 18-methyl group in the presence of (diacetoxyiodo)benzene. Using this methodology, two new analogues of calcitriol were prepared: the first contains a hydroxylated alkyl side chain attached at C-18 with the natural side chain replaced by an isopropylidene group; the second is a conformationally locked analogue due to an extra oxacycle between the C-18 and C-20 positions.
authors.affiliation: Departamento de Química Fundamental, Universidade da Coruña, E-15071 A Coruña, Spain.
authors.forename: Iván
authors.initials: I
authors.lastname: Cornella
authors.forename: José
authors.initials: J
authors.lastname: Pérez Sestelo
authors.forename: Antonio
authors.initials: A
authors.lastname: Mouriño
authors.forename: Luis A
authors.initials: LA
authors.lastname: Sarandeses
mesh_terms: D001667:Binding, Competitive; D002117:Calcitriol / Q000031:analogs & derivatives* / Q000138:chemical synthesis* / Q000737:chemistry; D002384:Catalysis; D020650:Combinatorial Chemistry Techniques / Q000379:methods*; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D010777:Photochemistry; D013237:Stereoisomerism; D013329:Structure-Activity Relationship; D014961:X-Ray Diffraction
chemical_list: D002117:Calcitriol