Drauz, Karl-HeinzKleemann, AxelMartens, JürgenScherberich, PaulEffenberger, Franz2009-10-192016-03-312009-10-192016-03-311986318083442http://nbn-resolving.de/urn:nbn:de:bsz:93-opus-43279http://elib.uni-stuttgart.de/handle/11682/1231http://dx.doi.org/10.18419/opus-1214Reaction of L-5-oxoproline esters L-2 with phosgene at 0° C gives L-5,51-dichloro-1-(chlorocarbonyl)proliene esters L-6 ,which readily lose hydrogen chloride to form L-5-chloro-1-(chloroarbonyl)-4,5-dehydroproline esters L-7. Catalytic hydrogenation (Pd/C, 180 bar) of L-7 yields L-1-(chlorocarbonyl)proline esters L-15 and thence, upon hydrolysis, L-proline ( L17 ). A "one-pot reaction" for the whole sequence is described, starting from easily accessible L-5-oxoproline esters and yielding L-proline in 78% overall yield and 99.7% optical purity.eninfo:eu-repo/semantics/openAccessProlin , Aminosäuren540article2014-10-16