134853-11-5Relevant academic research and scientific papers
Photochemically and Thermally Induced Free-Radical Reactions of α,β-Epoxy Ketones with Tributyltin Hydride: Selective Ca-O Bond Cleavage of Oxiranylmethyl Radicals Derived from α,β-Epoxy Ketones
Hasegawa, Eietsu,Ishiyama, Kenyuki,Kato, Tomoyasu,Horaguchi, Takaaki,Shimizu, Takahachi,et al.
, p. 5352 - 5359 (1992)
Free-radical reactions of α,β-epoxy ketones with tributyltin hydride have been studied.These substances were selectively converted to β-hydroxy ketones under both photochemical and thermal conditions.The photoreaction is initiated by hydrogen abstraction of an epoxy ketone triplet from tributyltin hydride, while azoisobutyronitrile is used as an initiator for the thermal reaction.In general, the photoreaction conditions are particularly useful for aroyl-substituted epoxy ketones while the thermal conditions are applicable to a variety of epoxy ketones.It was also found that the epoxy esters and epoxy alcohols did not undergo the ring-opening reaction under the similar conditions.Tributyltin radical attack on the carbonyl of epoxy ketones is a key process for both the photoreaction and the thermal reaction.Regioselective ring opening of the resulting oxiranylmethyl radical finally produces β-hydroxy ketones.In order to capture the free-radical intermediates, the reaction of epoxy ketones with allyltributyltin was conducted.The isolation of α-allylated β-hydroxy ketones is interpreted by the involvement of a novel 1,5-tributyltin transfer.
Dual Lewis Acid/Photoredox-Catalyzed Addition of Ketyl Radicals to Vinylogous Carbonates in the Synthesis of 2,6-Dioxabicyclo[3.3.0]octan-3-ones
Foy, Nicholas J.,Forbes, Katherine C.,Crooke, Anne Marie,Gruber, Maxwell D.,Cannon, Jeffrey S.
, p. 5727 - 5731 (2018)
A combined Lewis acid/photoredox catalyst system enabled the intramolecular umpolung addition of ketyl radicals to vinylogous carbonates in the synthesis of 2,6-dioxabicyclo[3.3.0]octan-3-ones. This reaction proceeded on a variety of aromatic ketones to provide THF rings in good yield (up to 95%). Although diastereoselectivity was found to be modest (1.4-5:1) for the C-C bond forming reaction, the minor diastereomers were converted to 2,6-dioxabicyclo[3.3.0]octan-3-ones by an efficient Lewis acid-mediated epimerization cascade in up to 90% yield.
Free radical trapping of α-keto radicals derived from α,β-epoxy ketones via photoinduced single electron transfer process
Hasegawa, Eietsu,Ishiyama, Kenyuki,Horaguchi, Takaaki,Shimizu, Takahachi
, p. 2029 - 2032 (2007/10/02)
Irradiation of aromatic α,β-epoxy ketones in the presence of allyltributyltin afforded α-allyl-β-hydroxy ketones by a single electron transfer mechanism.
