1.1: NaOH / methanol; tetrahydrofuran; H2O 2.1: LiHMDS / tetrahydrofuran / -78 °C 2.2: lithium tert-butyl peroxide / tetrahydrofuran; toluene / 2.5 h / -78 - 0 °C 2.3: 94 percent / tetrahydrofuran; toluene / 0.5 h / 0 °C View Scheme