65760-95-4Relevant academic research and scientific papers
Generation and reaction of monocarbonyliodonium ylides: Ester exchange of (Z)-(β-acetoxyvinyl)iodonium salts with lithium ethoxide and synthesis of α,β-epoxy ketones
Ochiai, Masahito,Kitagawa, Yutaka,Yamamoto, Shinji
, p. 11598 - 11604 (1997)
Reported here for the first time are the generation of monocarbonyliodonium ylides and their alkylidene-transfer reactions to aldehydes yielding α,β-epoxy ketones. Exposure of (Z)-(2-acetoxy-1-decenyl)iodonium bromide, prepared stereoselectively by sodium acetate-catalyzed Michael addition of acetic acid to (1-decynyl)(phenyl)iodonium salt, to EtOLi in THF at -78°C results in ester exchange to generate the monocarbonyliodonium ylide with the liberation of ethyl acetate. 1H NMR measurements indicate that the ylide is stable up to -30°C in THF-d8 but gradually decomposes at -20°C to 1-bromo-2-decanone. The monocarbonyliodonium ylide acts as an alkylidene-transfer agent to carbonyl compounds, and the reaction with aldehydes in THF-DMSO at -30°C gives α,β-epoxy ketones with E-isomers as a major product. With an α,β-unsaturated aldehyde, selective 1,2-addition to the carbonyl group was observed. The relative rates of the alkylidene-transfer reaction of this ylide for a series of ring-substituted benzaldehydes were measured. A Hammett correlation plot with the σ constants of substituents afforded the reaction constant ρ = 2.95 (r = 1.00), which indicates that the monocarbonyliodonium ylide is moderately nucleophilic in nature.
Oxidations with Lead Tetraacetate. V. Oxidations of 1,3-Benzoxathioles
Aromdee, Chantana,Cole, Edward R.,Crank, George
, p. 1255 - 1261 (2007/10/02)
2,2-Disubstituted 1,3-benzoxathioles are easily oxidized by lead tetraacetate to a complex mixture of products.Acetoxylation takes place on the first carbon atom of the 2-alkyl or -cycloalkyl substituent giving acetoxy derivatives.The hetero ring is also opened yielding ketones, acetoxyketones, a disulfide and polymeric materials.Oxidation at the sulfur atom appears to be a minor reaction and no products oxidized in the benzene ring are found.
