Scheme 1. (a) I₂, CAN, CH₃CO₂H, 80°C; (b) DMTrCl, pyridine, room temperature; (c) CF₃CH₂OH, Pd(PhCN)₂Cl₂, CO, Et₃N, CH₃CN, 60°C; (d) (1) H₂N(CH₂)₆NH₂, iPr₂NEt, DMF, room temperature, (2) CF₃CO₂Et, Et₃N, DMF, room temperature; (e) 2-cyanoethyl-N,N-diisopropylphosphoamidochloride, iPr₂NEt, CH₂Cl₂, room temperature; (f) succinic anhydride, DMAP, pyridine, 50°C; (g) aminopropyl controlled pore glass, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, DMF, room temperature.