Efficient Synthesis of Methyl 2-(tert-Butyl)acrylate and Analogous Esters

The title products are prepared via an efficient three-step synthesis which involves hydroalumination of methyl propiolate and Lewis-acid-promoted reaction with acetone in the presence of BF₃ followed by two highly selective S_N2′ reactions. The key step is the reaction of 2-(chloromethyl)acrylates with R₂CuLi/ZnCl₂ reagents which takes place with complete allylic rearrangement.