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Regio‐ and stereoselective alkylation of a pyrrolidinic system: Structural and conformational studies by high field NMR techniques
Author(s) -
Schaefer M.,
Faller P.,
Nicole D.
Publication year - 1982
Publication title -
organic magnetic resonance
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.483
H-Index - 72
eISSN - 1097-458X
pISSN - 0030-4921
DOI - 10.1002/mrc.1270190214
Subject(s) - enamine , chemistry , alkylation , regioselectivity , stereospecificity , protonation , stereoselectivity , pyrrolidine , stereochemistry , organic chemistry , ion , catalysis
Abstract A new merocyanine was prepared by addition of the pyrrolidine enamine of N ‐ethoxycarbonylpyrrolidine‐3‐one to 1‐octyne‐3‐one. This addition was regioselective (with an unexpected C‐4 alkylation of the pyrrolidinone‐3‐enamine) and stereospecific (exclusively trans addition to the triple bond). The structure and conformational equilibrium were studied by high resolution proton magnetic resonance (NOE and variable temperature effects). Activation parameters Δ H *, Δ S * and Δ G * are given, and the behaviour on protonation examined.