T=0°C; 16 h;

2: 95 percent / CBr4,<O2PCH2>2 / CH2Cl2 / 0.5 h / 0 °C 3: 70 percent / CuBr.Me2S, n-BuLi / tetrahydrofuran; hexamethylphosphoric acid triamide / -78 - -40 °C 4: H2/Lindlar / hexane; pyridine / 0.25 h / Ambient temperature 5: nBu4NF, HOAc / tetrahydrofuran View Scheme

1: 2) iodine / 1) dirhodium tetraacetate / 1) 18 h, 2) CH2Cl2, RT, 6 h 2: 1) NaH / 1) DME, 2h, RT, 2) 0.5 h 3: 45 percent / NaBH4 / H2O; ethanol / 2 h / Ambient temperature 4: 75 percent / LiOH / 1,2-dimethoxy-ethane / 1 h / Ambient temperature View Scheme

acetic acid; dirhodium tetraacetate in neat (no solvent) 2 h; Ambient temperature; Yield given. Yields of byproduct given;

dirhodium tetraacetate 18 h; Yield given. Yields of byproduct given;

sodium tetrahydroborate; cerium(III) chloride; acetic acid; dirhodium tetraacetate 1.) 2 hour, room temperature 2.) MeOH, 0 gradC; Yield given. Multistep reaction;

1: 1.) AcOH 2.) NaBH4, CeCl3 / <Rh(OAc)2>2 / 1.) 2 hour, room temperature 2.) MeOH, 0 gradC 2: AcOH, H2O / acetone View Scheme