1193690-08-2Relevant academic research and scientific papers
Phosphane-catalyzed [3+2] annulation of allenoates with aldehydes: A simple and efficient synthesis of 2-alkylidenetetrahydrofurans
Xu, Silong,Zhou, Lili,Ma, Renqin,Song, Haibin,He, Zhengjie
supporting information; experimental part, p. 8698 - 8702 (2010/03/25)
A phosphane-catalyzed [3 +2] annulation of γ-methyl allenoates with aromatic aldehydes has been reported. This annulation provides a convergent and efficient synthesis of 2-alkylidenetetrahydrofurans, which are versatile synthetic building blocks for a vast array of 5-membered oxygenated heterocycle derivatives. The EIZ isomers of 2-(ethoxycarbonylmethylene) tetrahydrofurans, was separated by column chromatography on silica gel and their structural assignments were confirmed by H and C NMR spectroscopy data and X-ray crystallographic analysis. The nature of the substituent, as well as the reaction conditions, has a significant influence on the reactivity patterns of γ-substituted allenoates with aldehydes. The phosphorus ylide, generated from the phosphonium dienolate 8 by an overall 1,4-hydrogen shift, is believed to be the key intermediate responsible for the [3 + 2] annulation and other transformations of γ-methyl allenoates with aldehydes.
