Scheme 2. Reagents and conditions: a) SOCl2, CH3OH, reflux, 4 h, 60%; b) lithium methoxide, anhydrous methanol, reflux, 12 h, 35%; c) NaOH, CH2Cl2, CH3OH, rt, 3 h, 98%; d) NaBH4, BF3·OEt2, THF, 0 °C–rt, 1 h, 99%; e) benzene, CH2Cl2, AlCl3, reflux, 5 h, 52.6%; f) BBr3, CH2Cl2, –40–0 °C, 12 h, 60%; g) H2, 10% Pd/C, CH2Cl2/CH3OH, 4 h, 99%; h) RCOCl, Et3N, THF, 0 °C–rt, 50–80% or RCOOH, triphenyl phosphite, toluene. For the R group, see Table 1.
