Synthesis of compounds for exploring the middle amino moiety.a
a Reagents and conditions: (a) ClCOOCH2Ph, CuI, THF, −10 °C; (b) i-PrMgCl, THF, −20 °C, 76%; (c) H2, RhCl(PPh3)3, toluene, 70 °C, 4 d, 95%; (d) 6 N HCl, reflux, 93%; (e) NaI/K2CO3, CH3CN, reflux, 6 h, 60% for 18, 62% for 19.