Compound 13 (2.58 g, 0.016 mol), triethylamine (2.3 mL, 0.016 mol), 3.5 mL (0.016 mol) of diphenylphosphoryl azide, and 16 mL of dry benzene were combined under Nz at 25" C; then the mixture was warmed and stirred under reflux for 4 h until the evolution of Nz ceased. Benzyl alcohol (8.5 mL, 0.082 mol) was added, and the resulting mixture was stirred under reflux for 15 h. The benzene was then removed under reduced pressure, and ...
