Scheme 1.
Reagents and conditions: (i) NIS, chloroform/acetic acid (1:1); (ii) K2CO3, PEPPSI-IPr, toluene/methanol (1:1); (iii) NaOH, H2O/dioxane (1:1); (iv) NaOH, H2O
Reagents and conditions: (i) NIS, chloroform/acetic acid (1:1); (ii) K2CO3, PEPPSI-IPr, toluene/methanol (1:1); (iii) NaOH, H2O/dioxane (1:1); (iv) NaOH, H2O