potassium tert-butylate in diethyl ether; dimethyl sulfoxide T=25°C; 12 h;

1: 1,2,3,4,6-pentamethylfulvene With lithium diisopropyl amide in tetrahydrofuran 2: methyl iodide in tetrahydrofuran T=-20°C; Title compound not separated from byproducts;

1: NaBH4 / methanol 2: 60 percent / Et3NSO2NCO2CH3 / tetrahydrofuran / 0.75 h / Heating 3: 95 percent / HCl / CH2Cl2 4: 92 percent / t-BuOK / dimethylsulfoxide; diethyl ether / 12 h / 25 °C View Scheme

1: 60 percent / Et3NSO2NCO2CH3 / tetrahydrofuran / 0.75 h / Heating 2: 95 percent / HCl / CH2Cl2 3: 92 percent / t-BuOK / dimethylsulfoxide; diethyl ether / 12 h / 25 °C View Scheme

1: 95 percent / HCl / CH2Cl2 2: 92 percent / t-BuOK / dimethylsulfoxide; diethyl ether / 12 h / 25 °C View Scheme