Scheme 1 Reagents and Conditions: (a) Chloroacetyl chloride, NaOH, CH2Cl2/H2O, rt, 1 h; (b) t-BuOK, toluene, rt, 3 h; (c) NaH, ethyl bromoacetate, DMF, N2, 0°C, rt, 1.5 h; (d) KOH, MeOH, reflux, 2 h.