Ligand exchange reaction of sulfoxides in organic synthesis: A novel method for generation of magnesium enolates and its application to synthesis of [α]-halocarboxylic acid derivatives and [α]-haloaldehydes
yields. The magnesium enolates derived from the α-chloro-α-sulfinyl acid derivatives were trapped with carbonyl compounds to afford the adducts, which were transformed to α, β-epoxy carboxylic acid derivatives. Thermal elimination of the sulfinyl group in the α-halo-α-sulfinyl acid derivatives and the α-halo-α-sulfinyl aldehydes gave α-halo-α, β-unsaturated carboxylic acid derivatives and α-halo-α,