Synthesis of N-methoxy-N-methyl-beta-enaminoketoesters: new synthetic precursors for the regioselective synthesis of heterocyclic compounds.
[Structure: see text] Weinreb amides react with the lithium or sodium acetylide of ethyl propynoate in a hitherto unexplored acyl substitution-conjugate addition sequence to furnish (E)-N-methoxy-N-methyl-beta-enaminoketoesters. This approach provides a diverse entry to densely functionalized heterocyclic compounds, including pyrazoles through regioselective cyclocondensations with hydrazines in a microwave-assisted reaction.
Persson
Tobias
T
Department of Natural Sciences, Bioorganic Chemistry Section, The Royal Danish Agricultural and Veterinary University, DK-1871 Frederiksberg C, Denmark.
Nielsen
John
J