Aoyagi Yutaka, Saitoh Yoshihiro, Ueno Tasuku, Horiguchi Mai, Takeya Koichi, Williams Robert M
School of Pharmacy, Tokyo University of Pharmacy & Life Science, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan.
J Org Chem. 2003 Sep 5;68(18):6899-904. doi: 10.1021/jo034441n.
Lipase TL-mediated kinetic resolution of (+/-)-5-benzyloxy-1-tert-butyldimethylsilyloxy-2-pentanol (5) at low temperature proceeded to give the corresponding (S)-alcohol 5 and (R)-acetate 6 in quantitative yields with high enantiomeric purity. The addition of bases such as pyridine, DMAP, 2,4- and 2,6-lutidines, or triethylamine considerably enhanced the rate of kinetic resolution. The alcohol (S)-5 and the acetate (R)-6 were converted to piperazic acid derivatives (R)- and (S)-3, respectively, via the intramolecular Mitsunobu reaction as a key step.
脂肪酶TL介导的（±）-5-苄氧基-1-叔丁基二甲基硅氧基-2-戊醇（5）在低温下的动力学拆分反应定量生成了对映体纯度高的相应（S）-醇5和（R）-乙酸酯6。加入吡啶、4-二甲氨基吡啶、2,4-和2,6-二甲基吡啶或三乙胺等碱可显著提高动力学拆分的速率。醇（S）-5和乙酸酯（R）-6通过分子内Mitsunobu反应作为关键步骤分别转化为哌嗪酸衍生物（R）-3和（S）-3。
