title: Radical cyclization in heterocycle synthesis. 12. Sulfanyl radical addition-addition-cyclization (SRAAC) of unbranched diynes and its application to the synthesis of A-ring fragment of 1alpha,25-dihydroxyvitamin D3.
abstract: Sulfanyl radical addition-addition-cyclization (SRAAC) of unbranched diynes proceeded smoothly to give cyclized exo-olefins, while the sulfanyl radical addition-cyclization-addition (SRACA) of diynes having a quaternary carbon gave cyclized endo-olefins. This method was successfully applied to the synthesis of A-ring fragment of 1alpha,25-dihydroxyvitamin D3.
authors.affiliation: Kobe Pharmaceutical University, Higashinada, Japan.
authors.forename: O
authors.initials: O
authors.lastname: Miyata
authors.forename: E
authors.initials: E
authors.lastname: Nakajima
authors.forename: T
authors.initials: T
authors.lastname: Naito
mesh_terms: D002117:Calcitriol / Q000138:chemical synthesis* / Q000737:chemistry; D006571:Heterocyclic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D015394:Molecular Structure; D013457:Sulfur Compounds / Q000737:chemistry*
chemical_list: D006571:Heterocyclic Compounds; D013457:Sulfur Compounds; D002117:Calcitriol