Reagents and conditions: (a) MeONa, 1-((4-(tert-butyl)phenyl)sulfonyl)butan-2-one, MeOH, 60 °C, overnight; (b) MeONa, 2-((4-(tert-butyl)phenyl)sulfonyl)acetonitrile, MeOH, room temperature, overnight; (c) EtOH, H2SO4, NaNO2, 50 °C, 4 h; (d) t-BuNO2, CuBr2, MeCN, N2, room temperature, 3 h; (e) KCN, CuCN, DMF, N2, 65 °C, 19 h; (f) tributyl(1-ethoxyvinyl)stannane, Pd(PPh3)4, toluene, 65 °C, 3 h; (g) conc. HCl, dioxane, room temperature, 1 h.