Base-promoted reactions of bridged ketones and 1,3- and 1,4-haloalkyl azides: competitive alkylation vs azidation reactions of ketone enolates.
The reactions of 1,3- and 1,4-haloalkyl azides with enolates of 2-norbornanone (and a ring-expanded analog) afford polycyclic 1,2,3-triazolines in good yields. The reaction occurs by the initial azidation of the ketone enolate, followed in order by triazoline formation and O-alkylation. An interesting element of this process is the preferential reaction of the alkyl azide with an enolate anion as opposed to the more familiar reaction of the alkyl halide (including Cl and I derivatives). Reactions of acyclic or monocyclic enolates generally lead to 1,2,3-triazoles but none of the alternative C-alkylation product.
Department of Medicinal Chemistry, 1251 Wescoe Hall Drive, Room 4070, Malott Hall, University of Kansas, Lawrence, Kansas 66045-758, USA.
Lei
L
Yao
Brenton T
BT
Smith
Jeffrey
J
Aubé
D000478:Alkylation; D001386:Azides / Q000737:chemistry*; D001952:Bridged-Ring Compounds / Q000737:chemistry*; D006846:Hydrocarbons, Halogenated / Q000737:chemistry*; D007659:Ketones / Q000737:chemistry*; D015394:Molecular Structure
D001386:Azides; D001952:Bridged-Ring Compounds; D006846:Hydrocarbons, Halogenated; D007659:Ketones