1: 1 percent / DIBAH / diethyl ether / -78 °C 2: p-TsOH / diethyl ether / 40 h / Heating 3: 2) 20percent NaOH / 1) HOAc, reflux, 6 d 2) MeOH, r.t., 30 min 4: 53 percent / CrO3, pyridine / 2 h / Ambient temperature 5: 1) LiAlH4 2) CrO3, pyridine / 1) ether, reflux, 2 h 2) r.t., 30 min View Scheme