1,8-diazabicyclo[5.4.0]undec-7-ene in tetrahydrofuran T=25°C; Elimination; Title compound not separated from byproducts;

1.1: NaH / tetrahydrofuran / 20 °C 1.2: tetrahydrofuran / 20 °C 2.1: 78 percent / DCC; DMAP / CH2Cl2 / 0 - 20 °C 3.1: LDA / tetrahydrofuran / 0.17 h / -78 °C 3.2: 88 percent / tetrahydrofuran / 0.5 h / -78 °C 4.1: Et3N / CH2Cl2 / 0 - 20 °C 5.1: DBU / tetrahydrofuran / 25 °C View Scheme

1.1: 78 percent / DCC; DMAP / CH2Cl2 / 0 - 20 °C 2.1: LDA / tetrahydrofuran / 0.17 h / -78 °C 2.2: 88 percent / tetrahydrofuran / 0.5 h / -78 °C 3.1: Et3N / CH2Cl2 / 0 - 20 °C 4.1: DBU / tetrahydrofuran / 25 °C View Scheme

1.1: LDA / tetrahydrofuran / 0.17 h / -78 °C 1.2: 88 percent / tetrahydrofuran / 0.5 h / -78 °C 2.1: Et3N / CH2Cl2 / 0 - 20 °C 3.1: DBU / tetrahydrofuran / 25 °C View Scheme