title: Synthesis of the C(7)-C(22) sector of (+)-acutiphycin via O-directed double free radical alkyne hydrostannation with Ph3SnH/Et3B, double I-Sn exchange, and double Stille coupling.
abstract: Herein a new double O-directed free radical hydrostannation reaction is reported on the structurally complex dialkyldiyne 11. Through our use of a conformation-restraining acetal to help prevent stereocenter-compromising 1,5-H-atom abstraction reactions by vinyl radical intermediates, the two vinylstannanes of 10 were concurrently constructed with high stereocontrol using Ph3SnH/Et3B/O2. Distannane 10 was thereafter elaborated into the bis-vinyl iodide 9 via O-silylation and double I-Sn exchange; double Stille coupling of 9, O-desilylation, and oxidation thereafter furnished 8.
authors: The School of Chemistry & Chemical Engineering and the Centre for Cancer Research and Cell Biology (CCRCB), the Queen's University Belfast , Stranmillis Road, Belfast BT9 5AG, Northern Ireland, United Kingdom.
authors: Karl J
authors: KJ
authors: Hale
authors: Maciej
authors: M
authors: Maczka
authors: Amarjit
authors: A
authors: Kaur
authors: Soraya
authors: S
authors: Manaviazar
authors: Mehrnoosh
authors: M
authors: Ostovar
authors: Milosz
authors: M
authors: Grabski
mesh_terms: D000480:Alkynes / Q000737:chemistry*; D005609:Free Radicals / Q000737:chemistry; D006571:Heterocyclic Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D018942:Macrolides / Q000138:chemical synthesis* / Q000737:chemistry; D008968:Molecular Conformation; D015394:Molecular Structure; D009947:Organotin Compounds / Q000737:chemistry; D010084:Oxidation-Reduction; D014753:Vinyl Compounds
chemical_list: D000480:Alkynes; D005609:Free Radicals; D006571:Heterocyclic Compounds; D018942:Macrolides; D009947:Organotin Compounds; D014753:Vinyl Compounds; C515767:acutiphycin; C569210:vinyl iodide