1.1: NaOMe / methanol 2.1: 58.3 percent / pyridine / 5 h / 0 - 10 °C 3.1: n,N-diisopropylethylamine / CHCl3 / 20 °C 4.1: 693 mg / NaOMe / methanol / 3 h / Heating 5.1: 97.1 percent / PPh3; DEAD / toluene / 20 °C 6.1: NaOMe / methanol / Heating 6.2: 89 percent / aq. AcOH / 100 °C View Scheme

1.1: NaOMe / methanol 2.1: 58.3 percent / pyridine / 5 h / 0 - 10 °C 3.1: SO3*pyridine; Et3N / dimethylsulfoxide / 3 h / 20 °C 4.1: 433 mg / NaBH4 / methanol; CH2Cl2 / 2.5 h / 20 °C 5.1: NaOMe / methanol / 1.5 h / Heating 5.2: 92 percent / aq. AcOH / 3 h / 100 °C View Scheme