Bicyclic molecules with the 1,7-diaza-6,6-dimethylbicyclo[2.2.1]heptane and 1,8-diaza-7,7-dimethylbicyclo[3.2.1]octane (1-aza-7,7-dimethyltropane) skeleton are shown to be efficiently synthesized via cyclization reactions of endocyclic N-acylhydrazonium intermediates. By using a protected β-ketoester as the internal nucleophile, azacocaine analogues are also accessible via this methodology.
Rutjes, Floris P. J. T.; Udding, Jan H.; Hiemstra, Henk, Heterocycles, 1992, vol. 33, # 1, p. 81 - 85
作者:Rutjes, Floris P. J. T.、Udding, Jan H.、Hiemstra, Henk、Speckamp, W. Nico
DOI:——
日期:——
Synthesis of bicyclic 3-pyrazolidinones via π-cyclization reactions of exocyclic <i>N</i>
-acylhydrazonium ions
作者:Floris P. J. T. Rutjes、Jan H. Udding、Henk Hiemstra、W. Nico Speckamp
DOI:10.1002/recl.19941130304
日期:——
The preparation of several a-fused 3-pyrazolidinones is described starting from 5,5-di-methyl-3-pyrazolidinone and using an acid-induced cyclization of a π-nucleophile tethered to N-1 onto a cationic carbon bonded to N-2 (an exocyclic N-acylhydrazonium intermediate). The cyclization reactions proceed best with activated π-nucleophiles such as allyl- and propargylsilanes. In the case of an ester substituent