Scheme 3.
(a) TiCl4·2THF (100 mol%), iPr2NEt (1.5 eq.), acid chloride (1.2 eq.), CH2Cl2, 18–24 h; (b) OsO4 (8 mol %), NMO (3 eq.), tBuOH/H2O (1:1), 3–7 days; (c) LiAlH4 (1.5 eq.), THF, 0.5–2 h; (d) NaIO4 (1.2 eq.), MeOH/H2O (3:1), 0.25–1 h; (e) Ag2CO3/Celite (2 eq.), toluene, reflux, 2–3 h; (f) H2, Pd/C (10% w/w), MeOH, 10 min.
