200260-75-9Relevant academic research and scientific papers
A novel abnormal michael reaction of 2-Acylmethyl-4,4-dimethyl-2-oxazolines with acetylenic ketones and Esters
Tohda, Yasuo,Yanagidani, Takeshi,Asaka, Noriko
, p. 810 - 822 (2016)
The first example of abnormal Michael reaction of an active methylene compound, 2-acylmethyl-4,4-dimethyl-2-oxazoline with acetylenic ketone in acetonitrile is reported. The reaction accompanies 1,3-migration of the acyl group of the substrate to give 2-(3-acyl-1-buten-4-on-1-yl)-2-oxazoline, which was easily cyclized to 5-acyl-2-pyridone derivatives by treatment with silica gel. Selectivity of the reaction depends on bulkiness of all the substituents of both the substrate and the reagent. The selectivity is interpreted in terms of reduced kinetic acidity of an initial anionic adduct intermediate by both steric and electronic factors.
Synthesis via 2-Acylmethyl-2-oxazoline. I. A Novel Synthesis of 3-Acyl-2-pyridones by Michael Addition of 2-Acylmethyl-2-oxazoline to αβ-Acetylenic Ketones
Tohda, Yasuo,Yanagidani, Takeshi,Hiramatsu, Shin-Ichi,Nishiwaki, Nagatoshi,Tani, Keita,Imagawa, Kazuko,Ariga, Masahiro
, p. 2781 - 2790 (2007/10/03)
The reaction of the sodium salt of 2-acylmethyl-4,4-dimethyl-2-oxazolines with α,β-acetylenic ketones in ethanol gave Michael adducts, which were easily transformed to 4,6-disubstituted 3-acyl-1-(2-hydroxy-1,1-dimethylethyl)-2-pyridones by silica gel. N-Dealkylation of the pyridones was performed using hydrochloric acid in good yields. Deacylation of the pyridones was performed using potassium hydroxide. A mild treatment of the pyridones with bases or silica gel gave 7-oxa-1-azabicyclo[4.3.0]non-3-en-2-one derivatives via intramolecular Michael addition. A similar reaction of 2-phenacyl-2-oxazoline with diphenylpropynone gave the corresponding 1-(2-hydroxyethyl)-2-pyridone derivative, which was inert against these 1-dealkylation, 3-deacylation, and intramolecular addition reactions.
