Scheme 2a.
aReagents and conditions:
(a) TFA, CH2Cl2, rt, 4 h; (b) 1,4-dihydronaphthalene oxide, NEt3, EtOH, 75 °C, 36 h; (c) TBDMSCI, imidazole, CH2Cl2, rt, overnight; (d) n-BuLi, THF, -78 °C, 4h; (e) 12N HCl, THF, rt.
aReagents and conditions:
(a) TFA, CH2Cl2, rt, 4 h; (b) 1,4-dihydronaphthalene oxide, NEt3, EtOH, 75 °C, 36 h; (c) TBDMSCI, imidazole, CH2Cl2, rt, overnight; (d) n-BuLi, THF, -78 °C, 4h; (e) 12N HCl, THF, rt.