1.1: ethylmagnesium bromide / tetrahydrofuran / 1.5 h / -15 - 0 °C 2.1: n-BuLi / tetrahydrofuran; hexane / 0 - 20 °C 2.2: 0.820 g / tetrahydrofuran; hexane / 3 h / 20 °C 3.1: sodium borohydride View Scheme

1.1: ethylmagnesium bromide / tetrahydrofuran / 1.5 h / -15 - 0 °C 2.1: n-BuLi / tetrahydrofuran; hexane / 0 - 20 °C 2.2: 0.820 g / tetrahydrofuran; hexane / 3 h / 20 °C 3.1: formic acid; triethylamine / [((S,S)-N-(1,2,6-triphenyl-3-azahexyl)tosylamido)RuCl] / 20 h / 40 °C View Scheme