1: 1-bromo-3,5-dimethyl-benzene With iodine; magnesium in tetrahydrofuran T=20 - 80°C; 2 h; Inert atmosphere; 2: (4R,5R)-dimethyl 2,2-diethyl-1,3-dioxolane-4,5-dicarboxylate in tetrahydrofuran T=0°C; 12 h; Inert atmosphereReflux;

1: tosic acid / benzene / Heating 2: tetrahydrofuran View Scheme

in tetrahydrofuran Yield given;