84641-70-3Relevant academic research and scientific papers
Aspects of the Mechanism of the Wittig Reaction Between Cyclic Anhydrides and Stabilized Phosphoranes
Abell, Andrew D.,Massy-Westropp Ralph A.
, p. 2077 - 2087 (2007/10/02)
It has been established that the Wittig reaction between cyclic anhydrides and ethoxycarbonylmethylenetriphenylphosphorane, a reaction used for the preparation of enol-lactones, proceeds via an acyclic intermediate acylated phosphorane for the three classes of anhydrides studied: succinic, maleic and phthalic.The formation of the acyclic intermediate can be irreversible or reversible, depending on the structure of the anhydride.The stereochemistry of the enol-lactones produced is not controlled by the initial reaction of the anhydride with the ylide but either during or after cyclization of the acyclic intermediate.Product formation appears to be under kinetic control with all the anhydrides studied.The influence of substituents in substituted phthalic anhydrides has been investigated
The Wittig Reaction with Glutaric and Succinic Anhydrides
Abell, Andrew D.,Doyle, Ian R.,Massy-Westropp, Ralph A.
, p. 2277 - 2287 (2007/10/02)
Six-membered cyclic anhydrides, including glutaric and some of its alkylated derivatives, have been shown to yield enol-lactones with ethoxycarbonylmethylenetriphenylphosphorane; the (E) isomer is formed preferentially.The reactions of methyl-substituted succinic anhydrides with the same phosphorane give predominantly the (E) enol-lactone in all examples.The influence of alkyl substituents on the rates of the reactions and the product ratios in both the succinic and glutaric anhydride series is discussed.
