Synthesis of Alkynyl-Glycinols by Lewis Acid Catalyzed Propargylic Substitution of Bis-Imidates
European Journal of Organic Chemistry 2015
Jekaterina Sirotkina, Liene Grigorjeva, Aigars Jirgensons

Racemic and enantioenriched alkynyl-glycinols can be synthesized by Lewis acid catalyzed cyclization reaction of bis-trichloracetimidates derived from alkynyl-glycols. The cyclization proceeds selectively to give 4-alkynyl-oxazolines as the propargylic substitution products. Enantioenriched bis-imidates that contain an alkyl or trimethylsilyl substituent at the acetylene gave oxazolines with complete inversion of configuration. In turn, considerable racemization was observed in the cyclization of bis-imidates that contain a phenyl substituent. The racemization for these substrates can be suppressed by introduction of the electronegative substituent at the phenyl ring. Oxazolines prepared by bis-imidate cyclization reaction can be readily transformed to protected alkynyl-glycol derivatives. Racemic and enantioenriched alkynyl-glycinol derivatives can be synthesized by Lewis acid catalyzed cyclization reaction of bis-trichloroacetimidates into oxazolines.


Atslēgas vārdi
Alkynes | Cyclization | Lewis acids | Nucleophilic substitution | Synthetic methods
DOI
10.1002/ejoc.201500937

Sirotkina, J., Grigorjeva, L., Jirgensons, A. Synthesis of Alkynyl-Glycinols by Lewis Acid Catalyzed Propargylic Substitution of Bis-Imidates. European Journal of Organic Chemistry, 2015, Vol.2015, Iss.31, 6900.-6908.lpp. ISSN 1434-193X. Pieejams: doi:10.1002/ejoc.201500937

Publikācijas valoda
English (en)
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