1.1: di-n-butylboryl trifluoromethanesulfonate; triethylamine / dichloromethane / 1 h / 0 °C / |Inert atmosphere 1.2: 2 h / -78 - -45 °C / |Inert atmosphere 2.1: 2,6-dimethylpyridine / dichloromethane / 0.5 h / 0 °C / |Inert atmosphere 3.1: 9-bora-bicyclo[3.3.1]nonane / tetrahydrofuran / 5 h / 0 - 23 °C / |Inert atmosphere 3.2: 15.5 h / 0 - 23 °C / pH 7 / |Inert atmosphere 4.1: potassium tert-butylate / tetrahydrofuran / 0.5 h / 0 °C / |Inert atmosphere View Scheme