1: 1.) Et3B 2.) NaBH4 / 1.) THF, r.t., 15 min 2.) MeOH, -70 deg C, 3 h 2: 68 percent / (PPh3)3RuCl2 / benzene / 72 h / Ambient temperature 3: 94 percent / H2 / Pd/C / ethyl acetate / 8 h / 760 Torr / Ambient temperature 4: 77 percent / p-toluenesulfonic acid / benzene / 5 h / Heating View Scheme

1: With 4 A molecular sieve; quinine-based catalyst in toluene T=50°C; oxy-Michael addition; 37 h; 2: With dihydrogen peroxide; sodium carbonate in ethyl acetate; toluene T=20°C; 0.25 h; Further stages. Title compound not separated from byproducts.;

trifluoroacetic acid in tetrahydrofuran; water T=0°C; 3 h;

mercury(II) perchlorate in tetrahydrofuran; chloroform T=20°C; ether cleavage; 0.0833333 h;

1: 88 percent / tetrapropylammonium perruthenate, 4-methylmorpholine oxide, molecular sieves 4 Angstroem / CH2Cl2 / 72 h / Ambient temperature 2: 1.) Mg / 1.) THF, 50 deg C, 30 min; 2.) THF, 50-60 deg C, 2 h 3: 72 percent / PCC, celite, molecular sieves 4 Angstroem / CH2Cl2 / 4 h / Ambient temperature 4: 78 percent / TFA / tetrahydrofuran; H2O / 3 h / 0 °C View Scheme

1: 1.) Mg / 1.) THF, 50 deg C, 30 min; 2.) THF, 50-60 deg C, 2 h 2: 72 percent / PCC, celite, molecular sieves 4 Angstroem / CH2Cl2 / 4 h / Ambient temperature 3: 78 percent / TFA / tetrahydrofuran; H2O / 3 h / 0 °C View Scheme

1: 72 percent / PCC, celite, molecular sieves 4 Angstroem / CH2Cl2 / 4 h / Ambient temperature 2: 78 percent / TFA / tetrahydrofuran; H2O / 3 h / 0 °C View Scheme

1: 93 percent / TBAF / tetrahydrofuran / 4 h / Ambient temperature 2: 88 percent / tetrapropylammonium perruthenate, 4-methylmorpholine oxide, molecular sieves 4 Angstroem / CH2Cl2 / 72 h / Ambient temperature 3: 1.) Mg / 1.) THF, 50 deg C, 30 min; 2.) THF, 50-60 deg C, 2 h 4: 72 percent / PCC, celite, molecular sieves 4 Angstroem / CH2Cl2 / 4 h / Ambient temperature 5: 78 percent / TFA / tetrahydrofuran; H2O / 3 h / 0 °C View Scheme

1: 57 percent / 4-Angstroem molecular sieves; BF3*OEt2 / CH2Cl2 / 1.5 h / 0 °C 2: 56 percent / 1.6M BuLi / tetrahydrofuran / 168000 h / 0 °C 3: 40 percent / TsOH / methanol / 24 h / 20 °C 4: 57 percent / Hg(ClO4)2*3H2O / tetrahydrofuran; CHCl3 / 0.08 h / 20 °C View Scheme

1: 40 percent / TsOH / methanol / 24 h / 20 °C 2: 57 percent / Hg(ClO4)2*3H2O / tetrahydrofuran; CHCl3 / 0.08 h / 20 °C View Scheme