Novel spiro cyclisations of N-acyliminium ions involving an aromatic π-nucleophile
作者:Patrick D. Bailey、Keith M. Morgan、David I. Smith、John M. Vernon
DOI:10.1016/0040-4039(94)88240-1
日期:1994.9
Several spiro 2-pyrrolidin-5-ones were obtained by a two-step procedure from N-substituted succinimides, involving spiro cyclisation of N-acyliminium ion intermediates in refluxing trifluoroacetic acid; in all cases cyclisation utilised a tethered aromatic π-nucleophile, and ring-closure followed 5- or 6-exo-trig pathways.
Spiro cyclisations of N-acyliminium ions involving an aromatic π-nucleophile
作者:Patrick D Bailey、Keith M Morgan、David I Smith、John M Vernon
DOI:10.1016/s0040-4020(03)00418-6
日期:2003.4
Spiro 2-pyrrolidin-5-ones were obtained from N-substituted succinimides by a two-step procedure, involving 5- or 6-endo-trig cyclisation of N-acyliminium ion intermediates with a tethered aromatic pi-nucleophile. (C) 2003 Elsevier Science Ltd. All rights reserved.
Preparation of optically active 4-substituted γ-lactones by lipase-catalyzed optical resolution
Abstract Opticallyactive 4-substituted γ-lactones (3 and 4) were synthesized effectively using lipase-catalyzed opticalresolution. N-methyl-4-hydroxyalkanamides (rac-1a–i) as substrates were prepared from N-methylsuccinimide. The alkylation of N-methylsuccinimide using Grignard reagents generated from various alkyl halides followed by reduction resulted in N-methyl-4-hydroxyalkanamides. The optical resolution