sodium amide

tetrabutyl ammonium fluoride in tetrahydrofuran 14 h; Heating;

1: 80 percent / 40percent Bu4NOH / CHCl3; H2O / 0.25 h 2: 69 percent / Bu4NF / tetrahydrofuran / 14 h / Heating View Scheme

1: ethanol / Heating 2: (i) LDA, (ii) /BRN= 969135/ 3: aq. H2SO4 / Heating View Scheme

in diethyl ether T=-78°C;

sulfuric acid; acetic acid in water 6 h; Heating;

1: K2CO3 / acetone / Heating 2: conc. H2SO4, acetic acid / H2O / 6 h / Heating View Scheme

1: Zn-Cu, I2 / diethyl ether / 96 h / Heating 2: (i) HCO2H, (ii) aq. NaOH 3: (i) B2H6, THF, (ii) aq. NaOH, H2O2, (iii) CrO3, Py View Scheme

titanium tetrachloride in dichloromethane T=0°C; 0.25 h; Yield given. Yields of byproduct given. Title compound not separated from byproducts;

1: 94.6 percent / Et3N / diethyl ether / 0.5 h / Ambient temperature 2: 78 percent / NaBH4, NaH, 2-propanol / dioxane / 1.) 70 deg C, 2.) reflux, 1 h 3: 97.8 percent / LDA / tetrahydrofuran / 1.) 1 h, -78 deg C, 2.) 2 h, ice bath, 3.) 0.5 h, r.t. 4: 100 percent / NaIO4 / H2O; methanol / 20 h / Ambient temperature 5: LDA / tetrahydrofuran / 1.) -78 deg C, 30 min, 2.) 30 min, ice bath 6: Al-Hg / tetrahydrofuran; H2O / 6 h / Heating View Scheme