787534-75-2Relevant academic research and scientific papers
Stereoselective follow-up reactions of (S)-2-sulfanyl nitriles
Gaupp, Sebastian,Effenberger, Franz
, p. 1777 - 1786 (2007/10/03)
Follow-up reactions of (S)-2-acetylthionitriles (S)-2 and (S)-2- benzylthionitriles (S)-4, respectively, are described. (S)-2- Acetylthionitriles were converted via Pinner reaction to ethyl (S)-2- mercaptocarboxylates (S)-3 almost without racemization. Two routes for the stereoselective preparation of 1,2-amino thiols (S)-5 have been investigated. Hydrogenation of (S)-2 with BH3 THF gave (S)-5 which, however, could not be isolated directly under the reaction conditions, but, by reaction with phosgene in an alkaline medium, the 1,2-amino thiols (S)-5 could be trapped as (S)-5-alkylthiazolidinones (S)-7 in good yields without racemization. (S)- Benzylthioamines (S)-6, derived from (S)-4 by hydrogenation with LiA1H4, were debenzylated with sodium in NH3 to give (S)-5 which were isolated as hydrochlorides with high enantiomeric excesses. Optically active thiomorpholines (S)-12 are accessible starting from (S)-2-(2- hydroxyethylthio)nitriles (S)- 10 which are first chlorinated with SOCl2 to yield (S)-2-(2-chloroethylthio)nitriles (S)-11 which after hydrogenation with LiAlH4 cyclize to give thiomorpholines (S)12.
