公开(公告)号：US09988331B2

公开(公告)日：2018-06-05

申请号：US13658003

申请日：2012-10-23

申请人： BASF SE

发明人： Gunnar Heydrich ,  Gabriele Gralla ,  Matthias Rauls ,  Joachim Schmidt-Leithoff ,  Klaus Ebel ,  Wolfgang Krause ,  Steffen Oehlenschläger ,  Christoph Jäkel ,  Marko Friedrich ,  Eike Johannes Bergner ,  Nawid Kashani-Shirazi ,  Rocco Paciello

IPC分类号： C07C29/56 ,  C07C29/17 ,  C07C29/78 ,  C07C45/62 ,  C07C45/82

CPC分类号： C07C29/56 ,  C07B2200/07 ,  C07C29/172 ,  C07C29/78 ,  C07C45/62 ,  C07C45/82 ,  C07C2601/14 ,  C07C2601/16 ,  C07C47/21 ,  C07C35/12 ,  C07C35/17

摘要： The present invention relates to a particularly economic overall method for producing menthol, specifically for producing optically active, essentially enantiomerically and diastereomerically pure L-menthol and racemic menthol, starting from the starting material citral which is available inexpensively on an industrial scale. The method has the following steps a.1) catalytic hydrogenation of neral and/or geranial to give citronellal, b.1) cyclization of citronellal to isopulegol in the presence of an acidic catalyst, c.1) purification of isopulegol by crystallization and d.1) catalytic hydrogenation of isopulegol to give menthol.