SnCl 5.聚苯乙烯+ CH3OCH2Cl A+ CH,OH A+ C CH2OCONHCH 2CO2 NHEt3 -+B+NHEt3 CI B+ HBr C CaHs CH2Br t CO2 CH2OCONHCH(CH3)COCL D t hBr E+C6H3CH,Br +CO2 FaCCO,H E+ HBr 5H1oO3N2)+G