1: 1.) BCl3, 2.) NaOH / 1.) CH2Cl2 2: adenosine deaminase / 72 h / 37 °C / phosphate buffer, pH 7-7.5 3: 1.) TMSCl, pyridine, 3.) NH4OH 4: TsOH / dioxane 5: DMAP / CH2Cl2 6: TBAF / tetrahydrofuran 7: Dowex-50 / methanol 8: NH4OH / 24 h / 55 °C View Scheme

sodium hydroxide; boron trichloride 1.) CH2Cl2; Multistep reaction;