1: imidazole / CH2Cl2 / 3 h 2: 1.) BuLi / 1.) THF, 0 deg C, 2 h, 2.) THF, 0 deg C, 8 h; 0 to 20 deg C 3: TBAF, H2O / tetrahydrofuran 4: 1.) H5IO6, MeNH2, 2.) HCl, H2O / 1.) MeOH, H2O 5: Et3N / CH2Cl2 / 3 h 6: 75 percent / NaIO4, RuO2*H2O, H2O / acetonitrile; CCl4 / 2 h View Scheme

indium in N,N-dimethyl-formamide T=20°C;

1: N-benzylidene-L-valinol With samarium; trimethylaluminum in hexane T=0°C; 2: allyl bromide in tetrahydrofuran T=0°C; 0.5 h;

samarium; iodine in tetrahydrofuran 0.5 h; Ambient temperature; Yield given. Yields of byproduct given;

1: sodium hydride / tetrahydrofuran / 1.) room temp., 1 h; 2.) 0 deg C, 16 h; 3.) room temp., 18 h 2: 10percent aq. hydrochloric acid View Scheme