Stereoselective synthesis of enantiopure 4,5-disubstituted pyrrolidin-2-ones by consecutive cuprate addition and N-acyliminium coupling
作者:Wim-Jan Koot、Henk Hiemstra、W.Nico Speckamp
DOI:10.1016/s0040-4039(00)74791-5
日期:1992.12
The enantiopure gamma-lactam (R)-1-acetyl-5-isopropoxy-3-pyrrolin-2-one (1), prepared from (S)-malic acid, undergoes cuprate addition at C4 with complete trans-stereoselectivity. The products react with pi-nucleophiles in the presence of Lewis acid at C5 to provide enantiopure 4,5-disubstituted pyrrolidin-2-ones.
Stereochemistry of allylic alkylation of the tetracarbonyliron complexes of (R)-1-acetyl-5-isopropoxy-3-pyrrolin-2-one
作者:Wim-Jan Koot、Henk Hiemstra、W. Nico Speckamp
DOI:10.1039/c39930000156
日期:——
The two diastereoisomeric title complexes react with allyltrimethylsilane in the presence of BF3·Et2O to give nucleophilic substitution at C-5 to the corresponding 5-allyl derivatives; the reaction of the cis-complex proceeds slowly and with predominant inversion, whereas the trans-complex reacts quickly and with complete retention of configuration at C-5.