Scheme 2. Synthesis of Fmoc–Qdiol(DTBS)–OH (19). Reagents and conditions: (a) DTBS ditriflate, anhydrous pyridine, anhydrous THF, –78 °C to r.t., 4 h; (b) 15, DIAD, PPh3, anhydrous THF, 0 °C to 50 °C, 5 h; (c) LiOH·H2O, THF/H2O, r.t., 1 h; (d) H2, Pd/C, THF, r.t., overnight; (e) Fmoc–Cl, dioxane/H2O, NaHCO3 (10% w/vol), 0 °C to r.t., overnight.
