G. Athanasellis et al., Synthesis and spectroscopic studies of 5-arylidene-3-substituted tetramic acids as possible substrates for catalytic asymmetric hydrogenation, J HETERO CH, 38(5), 2001, pp. 1203-1208
A new series of 5-arylidene-3-substituted tetramic acids 6-19 have been syn
thesized by a condensation reaction of 3-butanoyl tetramic acid 3, 3-ethoxy
carbonyl tetramic acid 4 and 3-acetyl tetramic acid 5 with a variety of sub
stituted benzaldehydes. The structures of the isolated compounds 6-19 have
been elucidated using FT-IR, H-1 and C-13-NMR spectroscopy, FAB-MS spectros
copy as well as elemental analyses.