63546-66-7Relevant academic research and scientific papers
Nucleophilic substitution reactions of sulfur-substituted cyclohexanone acetals: An analysis of the factors controlling stereoselectivity
Billings, Susan B.,Woerpel
, p. 5171 - 5178 (2006)
The reactions of cyclohexanone acetals substituted with thiophenyl groups (and other heteroatoms) at C-2 demonstrate the powerful influence that these substituents have on the stereoselectivity of nucleophilic substitution reactions. The trans selectivities of these reactions correlate with the behavior of the corresponding ketones. These experiments lend support to the possibility that the reactions of the acetals, which proceed via oxocarbenium ions, are operating under Felkin-Anh control.
Conformationally Biased Ketones React Diastereoselectively with Allylmagnesium Halides
Bartolo, Nicole D.,Demkiw, Krystyna M.,Read, Jacquelyne A.,Valentín, Elizabeth M.,Yang, Yingying,Dillon, Alexandra M.,Hu, Chunhua T.,Ward, Michael D.,Woerpel
, p. 3042 - 3065 (2022/02/25)
The addition of the highly reactive reagent allylmagnesium halide to α-substituted acyclic chiral ketones proceeded with high stereoselectivity. The stereoselectivity cannot be analyzed by conventional stereochemical models because these reactions do not conform to the requirements of those models. Instead, the stereoselectivity arises from the approach of the nucleophile to the most accessible diastereofaces of the lowest-energy conformations of the ketones. High stereoselectivity is expected, and the stereochemical outcome can be predicted, with conformationally biased ketones that have sterically distinguishable diastereofaces wherein only one face is accessible for nucleophilic addition. The conformations of the ketones can be determined by a combination of computational modeling and, in some cases, structure determination by X-ray crystallography.
