L'addition des organomagnesiens aliphatiques satures sur les triples liaisons disubstituees non conjuguees: IV. Influence d'un groupement fonctionnel thioether en α de la triple liaison. Action catalytique du cuivre

Abstract The addition reaction of ethylmagnesium bromide to the triple bond of the compounds of general formula EtSCH 2 C CCH 2 Y (where Y is the basic group OH, OR, NR 2 , or SEt) is very weakly activated by the thioether group. Catalysis by magnesium impurities may be involved. With 1-ethylthio-4-dialkylamino-2-butynes (Y NR 2 ), ( E ) trisubstituted ethylenic compounds are selectively obtained. The reaction more readily occurs after the addition of cuprous chloride to the Grignard solution, and then its stereoselecitvity may be reversed.