Scheme 3. Reagents and conditions: a) TIPDSCl2, py, r.t., 4 h; b) Dess–Martin periodinane, DCM, 0 °C to r.t., 18 h; c) NaBH4, EtOH, 0 °C to r.t., 1.5 h; d) Et3N·3HF, THF, r.t., 18 h; e) aq. NH3, dioxane, 100 °C, 20 h; f) 1 M NaOMe in MeOH, MeOH, r.t., 3 h; g) NaSMe, EtOH, r.t., 3 h; h) (Me)3Al (2 M in toluene), Pd(PPh3)4, THF; 70 °C, 18 h; i) R–B(OH)2, Na2CO3, Pd(OAc)2, TPPTS, H2O/MeCN (2 : 1), 100 °C, 2–4 h.
