Synthese und stereochemie von neuen 2-substituierten 4-thiazolidinylessigsäuren
作者:Jurgen Martens、Jürgen Kintscher、Wolfgang Arnold
DOI:10.1016/s0040-4020(01)96157-5
日期:1991.8
Reaction of isopropylidene-protected β-homopenicillamine 2 with various aldehydes leads to a number of new 2-monosubstituted 4-thiazolidine acetic acids 4. Thiazolidines 4 are formed with high diastereoselectivity. Assignment of configuration is made by NMR-analysis. The diastereomeric pure compounds 4 possess unstable chiral centers in position 2 and undergo rapid epimerisation in solution at higher
homopipecolic acid are prepared by α-amino alkylation of malonic acid with cyclic imines 6 and 7. These are prepared on a large scale and with different substitution patterns. The β-aminoacids 8 and 9 were formed in high yield and with remarkable diastereoselectivity if chiral imines are used as starting materials. The diastereoselectivity of the amino alkylation leading to homopipecolic acid analogues