methanol; Amberlyst-15 resin (H+ form) 3 h; Ambient temperature;

1: 1.) NaH / 1.) THF, 0 deg C, 30 min, 2.) THF, 0 deg C, 1 h 2: 96 percent / diisobutylaluminum hydride (DIBAL) / tetrahydrofuran; hexane / 0.25 h / 0 °C 3: 81 percent / pyridinium p-toluenesulfonate (PPTS) / CH2Cl2 / Ambient temperature 4: 1.) n-butyllithium / 1.) THF, hexane, -78 deg C, 1.5 h, 2.) THF, hexane, a) -78 deg C, 1 h, b) RT, 1 h 5: 1.) cuprous iodide / 1.) THF, ether, 0 deg C, 30 min, 2.) THF, ether, -78 deg C, 2 h 6: 95 percent / Amberlyst-15 resin (H+ form), methanol / 3 h / Ambient temperature View Scheme

1: 81 percent / pyridinium p-toluenesulfonate (PPTS) / CH2Cl2 / Ambient temperature 2: 1.) n-butyllithium / 1.) THF, hexane, -78 deg C, 1.5 h, 2.) THF, hexane, a) -78 deg C, 1 h, b) RT, 1 h 3: 1.) cuprous iodide / 1.) THF, ether, 0 deg C, 30 min, 2.) THF, ether, -78 deg C, 2 h 4: 95 percent / Amberlyst-15 resin (H+ form), methanol / 3 h / Ambient temperature View Scheme

1: 1.) DMSO, oxalyl chloride, 2.) Et3N / 1.) THF, -78 deg C, 1 h, 2.) THF, a) -78 deg C, 45 min, b) RT, 1 h 2: 1.) NaH / 1.) THF, 0 deg C, 30 min, 2.) THF, 0 deg C, 1 h 3: 96 percent / diisobutylaluminum hydride (DIBAL) / tetrahydrofuran; hexane / 0.25 h / 0 °C 4: 81 percent / pyridinium p-toluenesulfonate (PPTS) / CH2Cl2 / Ambient temperature 5: 1.) n-butyllithium / 1.) THF, hexane, -78 deg C, 1.5 h, 2.) THF, hexane, a) -78 deg C, 1 h, b) RT, 1 h 6: 1.) cuprous iodide / 1.) THF, ether, 0 deg C, 30 min, 2.) THF, ether, -78 deg C, 2 h 7: 95 percent / Amberlyst-15 resin (H+ form), methanol / 3 h / Ambient temperature View Scheme

1: 96 percent / diisobutylaluminum hydride (DIBAL) / tetrahydrofuran; hexane / 0.25 h / 0 °C 2: 81 percent / pyridinium p-toluenesulfonate (PPTS) / CH2Cl2 / Ambient temperature 3: 1.) n-butyllithium / 1.) THF, hexane, -78 deg C, 1.5 h, 2.) THF, hexane, a) -78 deg C, 1 h, b) RT, 1 h 4: 1.) cuprous iodide / 1.) THF, ether, 0 deg C, 30 min, 2.) THF, ether, -78 deg C, 2 h 5: 95 percent / Amberlyst-15 resin (H+ form), methanol / 3 h / Ambient temperature View Scheme

1: 1.) n-butyllithium / 1.) THF, hexane, -78 deg C, 1.5 h, 2.) THF, hexane, a) -78 deg C, 1 h, b) RT, 1 h 2: 1.) cuprous iodide / 1.) THF, ether, 0 deg C, 30 min, 2.) THF, ether, -78 deg C, 2 h 3: 95 percent / Amberlyst-15 resin (H+ form), methanol / 3 h / Ambient temperature View Scheme

1: 1.) cuprous iodide / 1.) THF, ether, 0 deg C, 30 min, 2.) THF, ether, -78 deg C, 2 h 2: 95 percent / Amberlyst-15 resin (H+ form), methanol / 3 h / Ambient temperature View Scheme

Yield given. Multistep reaction. Further byproducts given. Yields of byproduct given;

Yield given. Multistep reaction. Further byproducts given. Yields of byproduct given. Title compound not separated from byproducts;