Late-stage functionalization of estrone^a,b,c,d.

^aReaction conditions: 7 (0.2 mmol) in 5% aqueous xylene (2 mL, 0.1 M) under an inert atmosphere at 100 °C for 8 h.

^bThe diastereomeric ratio of 7a (12 : 1), 7b (15 : 1), 7c (9 : 1) and 7d (15 : 1) assigned by ¹H NMR after column purification.

^cIsolated yields of 8.

^dThe diastereomeric ratio of 8 (dr = >30 : 1) assigned by ¹H NMR analysis of the crude aliquot.