Synthesis of compounds 24 and 25.
aReagents and conditions: (a) 16, Pd(Ph3)4, potassium carbonate, dioxane, 120 °C, 42%; (b) (i) O3, DCM, −78 °C; (ii) sodium borohydride, −78 to 0 °C, 14%; (c) mesyl chloride, triethylamine, DCM, 0 °C, (d) 4, potassium carbonate, ACN, 50 °C; (e) phenylacetic acid, diisopropylethylamine, HATU, DMF, 0 °C to rt, 11% (from 22).