79068-35-2Relevant academic research and scientific papers
Synthesis of Proline Compounds cis- and trans-Substituted at C-3
Haeusler, Johannes
, p. 1073 - 1088 (2007/10/02)
Derivatives 1 of 1-pyrroline-2-carboxylic acid react with N-chloro- or N-bromosuccinimide, lead(IV) acetate, and azodicarboxylates to give the compounds 2, 4, and 6.Exchange of halogen in 2 affords the thiocompounds 3.Reduction of 2, 3, 4, and 6 with sodium tetrahydroborate leads to cis- (8dc - 8fc and 8hc - 8kc) but also to trans-configurated (8at and 8bt) amino acids; with amine-borane complexes trans-configurated amino acids are obtained predominantly.The trans-configurated amino acids 8gt -8jt, and 8lt have been synthesized by β-addition of appropriate nucleophils to methyl 1-acetyl-2-pyrroline-2-carboxylate (9a) and subsequent hydrolysis.An improved synthesis of 9a from methyl 1-pyrroline-2-carboxylate (1a) is described.
