HIEMSTRA, H.;FORTGENS, H. P.;SPECKAMP, W. N., TETRAHEDRON LETT., 1984, 25, N 29, 3115-3118
作者:HIEMSTRA, H.、FORTGENS, H. P.、SPECKAMP, W. N.
DOI:——
日期:——
Expedient Pyrrolizidine Synthesis by Propargylsilane Addition to<i>N</i>-Acyliminium Ions followed by Gold-Catalyzed α-Allenyl Amide Cyclization
作者:Arjen C. Breman、Jan Dijkink、Jan H. van Maarseveen、Sape S. Kinderman、Henk Hiemstra
DOI:10.1021/jo901393y
日期:2009.8.21
A reaction sequence, involving the addition of (substituted) propargylsilanes to lactam-derived N-acyliminiumions followed by gold-catalyzed cyclization of the resulting α-allenyl amide, is applied in expedient syntheses of pyrrolizidinealkaloids heliotridine and ent-retronecine in five steps from (S)-malic acid.
Lewis acid induced reactions of propargyl trimethyl silane with ω-ethoxy lactams synthesis of γ-allenyl-GABA
作者:Henk Hiemstra、Hendrikus P. Fortgens、W. Nico Speckamp
DOI:10.1016/0040-4039(84)80022-2
日期:——
Reactions of propargyl trimethyl silane with ω-ethoxy lactams 1a-c under the influence of borontrifluoride etherate afford ω-allenyl lactams 3a-c; 5-allenyl-2-pyrrolidinone is hydrolysed to γ-allenyl-GABA.