Premium
Synthesis of Polysubstituted Pyrrolizidines from Proline Derivatives and Conjugated Nitroolefins
Author(s) -
Felluga Fulvia,
Pitacco Giuliana,
Visintin Cristina,
Valentin Ennio
Publication year - 1997
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19970800510
Subject(s) - chemistry , regioselectivity , conjugated system , pyrrolizidine , proline , cycloaddition , ylide , alkyl , azomethine ylide , 1,3 dipolar cycloaddition , organic chemistry , stereochemistry , catalysis , amino acid , biochemistry , polymer
The stereochemistry of 1,3‐dipolar cycloaddition of azomethine ylides derived from aromatic aldehydes and i‐proline alkyl esters with several nitroolefins was investigated. Cyclic and acyclic nitroolefins add to the anti form of the ylide in a highly diastereoselective but poorly regioselective manner to give pyrrolizidine derivatives. In a few cases, the stereochemical results strongly support a stepwise mechanism.