SYNTHESIS OF 2S,5S-AND 2R,5S-5-HYDROXYPIPECOLIC ACID VIA AMIDE-METHYLENATION OF S-5-HYDROXY-2-PIPERIDONE WITH DIMETHYLTITANOCENE

被引:39
作者
HERDEIS, C
HELLER, E
机构
[1] Institut für Pharmazie und Lebensmittelchemie der Universität 8700 Würzburg, Am Hubland
关键词
D O I
10.1016/S0957-4166(00)82257-0
中图分类号
O61 [无机化学];
学科分类号
070301 ; 081704 ;
摘要
A route to 2S,5S-and 2R,5S-hydroxypipecolic acid is presented, starting with the enantiopure 5S-5-hydroxy-piperidone 7. The key step of this reaction sequence is the chemoselective methylenation of the amide carbonyl group of 8 with dimethyltitanocene 9 to 10. The transformation of the exocyclic enecarbamate double bond to the carboxylic acid group is best accomplished via hydroboration/oxidation to the alcohol 11a,b. Separation and oxidation of the diastereomers 11a,b, to 14a, and 14b, and hydrolysis furnishes the diastereomeric pipecolic acids 15a and 15b in enantiopure form.
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页码:2085 / 2094
页数:10
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