1: 94 percent / imidazole / dimethylformamide / 4 h / 25 °C 2: 1.) n-butyllithium, 2.) Gilman reagent, cuprrous cyanide, HMPA 3: H2, triethylamine / Lindlar catalyst / hexane / 760 Torr 4: tetra-n-butylammonium fluoride / tetrahydrofuran / 25 °C 5: 25 °C / saponification View Scheme