1.1: 97 percent / Et3N; imidazole / dimethylformamide / 20 °C 2.1: n-BuLi; CuCN; MeLi / diethyl ether / 3.08 h / -78 - 0 °C 2.2: diethyl ether; hexane / 0.33 h / -78 °C 3.1: pyridinium p-toluenesulfonate / acetone; H2O / 4 h / 20 °C 4.1: 89 percent / porcine pancreatic lipase; NaCl; CaCl2 / H2O; tetrahydrofuran / 0.5 h / Enzymatic reaction; pH 7.1 View Scheme

1: aq. HCl 2: (i) Li, Et2O, (ii) (nBu)3P*CuI, (iii) /BRN= 1435951/ View Scheme