Fig. 14 in A comprehensive review: Biological activity, modification and synthetic methodologies of prenylated flavonoids

Fig. 14. Synthesis of icaritin derivatives (393–402). Reagents and conditions: (a) ethyl iodoacetate, K2CO3, acetone, reflux, 12 h; (b) LiOH, THF, H2O, RT, 1.5 h; (c) corresponding basic amino acid, DIC, HOBt, anhydrous DMF, RT, overnight, His = histidine, Arg = arginine, Lys = lysine; (d) corresponding basic amino acid, HATU, DIPEA, anhydrous DMF, RT, overnight; (e) piperidine, DMF, RT, 20 min.