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A Novel Synthesis Of Cyclic And Acyclic 3-Alkenoic Acids Via Ionization/Elimination Of Β-Lactones, Stephen Lucas Maluleka

Masters Theses

Exposure of spiro β-lactones and 3-substituted 4,4-dialkyl oxetan-2-ones to magnesium bromide in diethyl ether solvent resulted in the smooth generation of β,γ-unsaturated acid derivatives in high yield and isomeric purity. It is believed that this reaction occurs via the formation of a stable tertiary carbocation at the β-carbon resulting from cleavage of the carbon-oxygen sigma bond due to the complexation of magnesium cation with the ring oxygen atom. Rapid loss of an adjacent proton then furnishes the unsaturated acids. The β-lactone precursors were prepared by the dehydration of β-hydroxy acid derivatives (obtained from the condensation of ketones with acetic acid …