Multi-step reaction with 3 steps 1: 72 percent / Et3N, DMAP / tetrahydrofuran / Ambient temperature2: LiAlH4, LiI, TBSOH / toluene; various solvent(s) / 23 h / -30 - -25 °C3: 48 percent / Et3N, pancreatin / various solvent(s) / 7 h / Ambient temperature  

Multi-step reaction with 4 steps 1.1: sodium tetrahydroborate; cerium(III) chloride heptahydrate / methanol / 2 h / -70 - -60 °C2.1: 4-(N,N-dimethlyamino)pyridine; triethylamine / N,N-dimethyl-formamide / 16 h / 10 - 30 °C / Inert atmosphere3.1: disodium hydrogenphosphate / water / 14 h / 25 - 30 °C / pH 7 / Enzymatic reaction4.1: sodium hydride / tetrahydrofuran; mineral oil / 2 h / 25 - 45 °C / Inert atmosphere4.2: 22 h / 25 - 30 °C / Inert atmosphere