sodium hydroxide; N-benzyl-N,N,N-triethylammonium chloride in tetrahydrofuran T=0 - 20°C; methoxymethylation; 2 h;

1: 1) Bu4NI, NaH / 1) DMF, 10 min., r.t., 2) r.t., 24 h 2: m-chloroperbenzoic acid / CH2Cl2 / 16 h / Ambient temperature 3: 10percent aq.KOH / methanol / 12 h / 25 °C 4: 1) Bu4NI, NaH / 1) DMF, r.t., 0.5 h, 2) 72 h, 25 deg C View Scheme

tetra-(n-butyl)ammonium iodide; sodium hydride 1) DMF, r.t., 0.5 h, 2) 72 h, 25 deg C; Yield given. Multistep reaction;

1: 65 percent / Et3N, Ph3P / Pd(OAc)2 / 12 h / 80 °C 2: 95 percent / H2 / Pd/C / ethanol 3: 84 percent / (COCl)2 / CH2Cl2; dimethylsulfoxide / 1 h / -78 °C 4: 66 percent / NaNH2 / tetrahydrofuran / 2 h / -78 °C 5: 94 percent / 48percent HBr / ethanol / 1 h 6: 94 percent / Ag2CO3 / benzene / 2 h View Scheme