1: 2-(2-propynyloxy)-tetrahydro-2H-pyran With n-butyllithium in tetrahydrofuran; hexane T=-78°C; 2 h; 2: acetaldehyde in tetrahydrofuran; hexane T=-78°C; 1 h; Further stages.;

1.1: 84 percent / p-TsOH / tetrahydrofuran / 2 h / 20 °C 2.1: n-BuLi / tetrahydrofuran; hexane / 2 h / -78 °C 2.2: 100 percent / tetrahydrofuran; hexane / 1 h / -78 °C View Scheme

diethyl ether

1: 70 percent / LiAlH4 2: pyridine / CH2Cl2 / 15 h / 20 °C View Scheme

1: pyridine / 1 h / 20 °C 2: pyridinium p-toluenesulfonate / methanol / 20 h / 20 °C 3: 93 percent / H2 / Lindlar catalyst, quinoline / benzene / 0.17 h / 20 °C 4: 69 percent / MnO2 / CH2Cl2 / 27 h / 20 °C 5: 26 percent / 35percent H2O2, NaHCO3 / methanol / 2 h / 0 °C 6: 2.) I2, HCO2H / 1.) MeOH, 20 deg C, 16 h, 2.) 1 h 7: 84 percent / 0.1 M KOH / methanol / 1 h / 100 °C View Scheme

lithium aluminium tetrahydride

1.1: DMPU / tetrahydrofuran; hexane / 20 °C 2.1: PPTS / methanol 3.1: LiAlH4 / diethyl ether / 20 °C 3.2: I2 / diethyl ether / -78 - 20 °C 4.1: pyridine / CH2Cl2 / 20 °C View Scheme

1: 70 percent / LiAlH4 2: 68 percent / pyridine / CH2Cl2 / 16 h / 20 °C View Scheme

toluene-4-sulfonic acid in methanol 1.5 h; Ambient temperature;