Attempted amino acid coupling: glycine ethyl ester, N,N'-dicyclohexyl carbodiimide (DCCI) or 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDAC), 1-hydroxybenzotriazole (HOBt), water, room temperature.
Synthesis of the BC ring system. DCC=dicyclohexylcarbo-diimide, DMAP=4-dimethylaminopyridine, DIBALH=diisobutylaluminum hydride, R=o-tolyl.