Practical Syntheses of Enantiomerically Pure Key Intermediates of Opioid Receptor-like 1 (ORL1) Antagonists - Yoshizumi, Takashi; Ohno, Akio; Tsujita, Tomohiro; Takahashi, Hirobumi; Okamoto, Osamu; Hayakawa, Ichiro; Kigoshi, Hideo (Synthesis, 2009)