Reagents: (a) TBDMSCl, imidazole, room temp, THF, 24 h; (b) i) Tf2O, triethylamine, 0 °C to room temp, 8 h, ii) TBAF, rt, 15 min; (c) dimethyl vinylphosphonate, Pd(PPh3)2Cl2, triethylamine, DMF, 120 °C, 24 h; (d) BrCH2COOCH3, Cs2CO3, CH3CN, room temp, 24 h; (e) CH2=CH(CH2)nCOOR, Pd(PPh3)2Cl2, triethylamine, DMF, 120 °C, 24 h; (f) ethyl acrylate, Pd(PPh3)2Cl2, triethylamine, DMF, 120 °C, 24 h; (g) BrCH2(CH2)nCH2COOR, Cs2CO3 or K2CO3, CH3CN, room temp, 24 h; (h) 2 N KOH, MeOH, room temp, 24 h.