Sequential substitution of 1,2-dichloro-ethene: a convenient stereoselective route to (9Z,11E)-, (10E,12Z)- and (10Z,12Z)-[1-14C] conjugated linoleic acid isomers
作者:O. Loreau、A. Maret、J.M. Chardigny、J.L. Sébédio、J.P. Noël
DOI:10.1016/s0009-3084(00)00229-2
日期:2001.3
Conjugated linoleic acid (CLA) isomers are present in human foods derived from milk or ruminant meat. To study their metabolism, (9Z,11E)-, (10E,12Z)- and (10Z,12Z)-[1-(14)C]-octadecadienoic acids with high radiochemical and isomeric purities (>98%) were prepared by stereoselective multi-step syntheses involving sequential substitution of 1,2-dichloro-ethene. In the case of the (9Z,11E) isomer, a first
共轭亚油酸(CLA)异构体存在于源自牛奶或反刍动物肉的人类食品中。为了研究它们的代谢,通过以下方法制备了具有高放射化学和异构纯度(> 98%)的(9Z,11E)-,(10E,12Z)-和(10Z,12Z)-[1-(14)C]-十八碳二烯酸。立体选择性多步合成,涉及顺序取代1,2-二氯乙烯。在(9Z,11E)异构体的情况下,由(7)-获得的(E)-1,2-二氯乙烯与2-非8-炔氧基-四氢吡喃之间的第一次金属催化的交叉偶联反应溴庚烷-1-醇,得到共轭的1,6-二炔。与己基溴化镁的第二次偶联反应提供了庚二炔基衍生物。立体选择性地还原三键和溴化得到(7E,9Z)-17-溴-庚烷-7,9-二烯。格氏试剂的形成并用14CO(2)碳酸化,得到(9Z,11E)-[1-(14)C]-十八烷基-9,11-二烯酸(7-溴-庚烷-1-醇的总产率为14.4%)。(10E,12Z)-和(10Z,12Z)-[1-(14)C]-十八烷基-10