1: phenylacetic acid With n-butyllithium; (R,R)-N,N'-di-(1-phenyl-2-(1-piperidinyl)ethyl)-1,3-propanediamine in tetrahydrofuran; hexanes T=0°C; Inert atmosphere; 2: (4S)-4-(2-iodoethyl)-2,2-dimethyl-1,3-dioxolane in tetrahydrofuran; hexanes T=-78°C; 2 h; Inert atmosphere; 3: diazomethyl-trimethyl-silane in diethyl ether; acetic acid T=0 - 24°C; Inert atmosphere; optical yield given as percent dediastereoselective reaction;