1: 3-oxo-1,3-dihydro-isobenzofuran With lithium hexamethyldisilazane in tetrahydrofuran T=-78°C; 0.416667 h; Inert atmosphere; 2: citraconic acid dimethyl ester in tetrahydrofuran T=-78 - 20°C; Inert atmosphere; regioselective reaction;

1: 3-oxo-1,3-dihydro-isobenzofuran With lithium hexamethyldisilazane in tetrahydrofuran T=-78°C; 0.416667 h; Inert atmosphere; 2: dimethyl 2-methylenesuccinate in tetrahydrofuran T=-78 - 20°C; Inert atmosphere; regioselective reaction;