1: 75 percent / NaOMe / methanol / 18 h / Heating 2: 82 percent / air / ethanol; aq. NaOH / 24 h / Ambient temperature 3: 0.41 g / 15percent HClO4 / 8 h / Heating 4: 79 percent / trifluoroacetic anhydride / tetrahydrofuran / 12 h / Ambient temperature 5: 59 percent / LiI / dimethylformamide / 5 h / Heating View Scheme

Multi-step reaction with 2 steps 1: LDA / tetrahydrofuran; hexane / Ambient temperature2: diethyl ether  

With  sodium methylate in  methanol 18 h;  Heating;   

Multi-step reaction with 2 steps 1: 75 percent / NaOMe / methanol / 18 h / Heating2: 82 percent / air / ethanol; aq. NaOH / 24 h / Ambient temperature  

Multi-step reaction with 4 steps 1: 75 percent / NaOMe / methanol / 18 h / Heating2: 82 percent / air / ethanol; aq. NaOH / 24 h / Ambient temperature3: 0.41 g / 15percent HClO4 / 8 h / Heating4: 79 percent / trifluoroacetic anhydride / tetrahydrofuran / 12 h / Ambient temperature  

Multi-step reaction with 4 steps 1: 75 percent / NaOMe / methanol / 18 h / Heating2: 82 percent / air / ethanol; aq. NaOH / 24 h / Ambient temperature3: 0.41 g / 15percent HClO4 / 8 h / Heating4: 33 percent / BBr3 / CH2Cl2 / -78 deg C then r.t., 1 h