Reagents and conditions for 12. (a) 2-Methoxyethoxymethyl Chloride, i-Pr2EtN, CH2Cl2, 0°C → rt; (b) Benzonitrile, H2O2, i-Pr2EtN, MeOH, 0°C, 3 hr; (c) 5, TFA, CH2Cl2, 30 min; (d) HBTU, HoBt,i-Pr2EtN, CH2Cl2, rt, 12 hr; (e) TBAF, THF, 1 hr. *(e) precedes (d): 7a was deprotected with TBAF before it was coupled to 7.