Preparation of Michael Adducts of Isobutyraldehyde and Acetylenecarboxylic Esters<i>via</i><i>N</i>-Isobutylidene-<i>t</i>-butylamine
作者:Shingo Miyajima、Kunio Ito
DOI:10.1246/bcsj.58.2659
日期:1985.9
N-Isobutylidene-t-butylamine reacted with methylpropiolate or dimethylacetylenedicarboxylate to afford the Michael adducts predominantly. The adducts were converted to the corresponding formyl esters.
(<i>Z</i>)- and (<i>E</i>)-4,4-Dimethyl-5-oxo-2-pentenoic Acids and Their Derivatives
作者:Kunio Ito、Shingo Miyajima
DOI:10.1246/bcsj.59.815
日期:1986.3
(Z)-4,4-Dimethyl-5-oxo-2-pentenoic acid (1) exists almost exclusively in the hydroxy lactone form, the tautomeric equilibrium constant (K=[Ring]/[Chain]) being 2.8×103 in water as estimated by the pKa method. Several examples are described of preference for ring forms of derivatives of 1, which are capable of exhibiting ring-chain tautomerism. (E)-4,4-Dimethyl-5-oxo-2-pentenoic acid (7) reacts with