Synthesis of Pulvinic Derivatives via TBAF-Mediated Regioselective Opening of an Unsymmetrical Monoaromatic Pulvinic Dilactone

摘要

The synthesis of the monoaromatic pulvinic dilactone I from a tetronic acid derivative is reported. The reaction of 1 with various amines was found to provide the two pulvinamides regioisomers 2a and 2b. Using tetrabutylammonium fluoride (TBAF) as an activator, pulvinamides 2a could be obtained with excellent regioselectivities and good yields. Additions of alcohols to I are also studied, leading to similar observations.