351196-83-3

Upstream product

• 187884-05-5 (2S)-2-[(tert-butoxycarbonyl)amino]-3-methylbutanethioic S-acid 
• 13734-41-3 t-Boc-L-valine 
• 212070-55-8 tert-butyl N-<(1S)-2-methyl-1-<<<1,1-dimethyl-2--2-thioxoethyl>amino>carbonyl>propyl>carbamate 

Downstream Products

• 351196-84-4 benzyl N-((S)-1-benzyl-2-{[(S)-2-({1,1-dimethyl-2-[methyl(phenyl)amino]-2-thioxoethyl}amino)-1-(1-methylethyl)-2-oxoethyl]amino}-2-oxoethyl)carbamate 

Relevant academic research and scientific papers

Scope and limitation of the acid-catalyzed isomerization of Aib-containing thiopeptides

The use of amino thio S-acids in the 'azirine/oxazolone method' and a novel isomerization led to Aib-containing endothiopeptides. With the aim of generalizing this method, a variety of Aib-containing dipeptide thioanilides have been prepared. By their treatment with ZnCl2 in AcOH, followed by HCl-saturated AcOH, the C=S group was shifted from the last to the penultimate amino acid in high yield and without epimerization. As this methodology is very useful for the specific introduction of a thioamide group, it was extended to Aib-containing tripeptides. In addition, it could be shown that a mechanism via spirocyclic intermediates (cf. Scheme 4) is most likely for this isomerization. To establish the proposed neighboring-group participation of the N-acyl group, model dipeptide thioanilides containing no N-terminal C=O group were synthesized. These derivatives did not undergo rearrangement.

A novel acid-catalyzed isomerization of Aib-containing thiodipeptides

The use of amino thioacids in the 'azirine/oxazolone method' led to completely epimerized Aib-containing endothiodipeptides (Aib=2- aminoisobutyric acid). It could be established that the epimerization occurred during the acidic hydrolysis of the primaril