1.1: 64 percent / PS-D lipase / 264 h / 20 °C 2.1: 92 percent / n-Bu4NF / tetrahydrofuran / 5 h / 20 °C 3.1: 78 percent / tetra-(n-propyl)ammonium perruthenate; NMO / CH2Cl2 / 12 h / 20 °C 4.1: Li / diethyl ether 4.2: diethyl ether / 0.08 h / -78 °C View Scheme