Direct vinylogous Mannich-type reactions via ring opening and rearrangement of vinyloxiranes.
[reaction: see text] The first synthetic application of 2-methyl-2-vinyloxirane as a masked dienolate has been successfully demonstrated in the direct vinylogous Mannich-type reaction with an alpha-imino ester as an electrophile. The Mannich adduct was a useful intermediate en route to cis-5-substituted pipecolinic acid ethyl ester under simple hydrogenation conditions.
Lautens
Mark
M
Davenport Research Laboratories, Department of Chemistry, University of Toronto, Toronto, Ontario, Canada M5S 3H6. mlautens@chem.utoronto.ca
Tayama
Eiji
E
Nguyen
Duy
D