A New General Method for the Synthesis of 1,3-Disubstituted 5-Cyano-4-methylthio-6-oxo-1,6-dihydropyrano[2,3-c]pyrazoles Using α-KetoketeneS,S-Acetals1
A New General Method for the Synthesis of 1,3-Disubstituted 5-Cyano-4-methylthio-6-oxo-1,6-dihydropyrano[2,3-<i>c</i>]pyrazoles Using α-Ketoketene<i>S</i>,<i>S</i>-Acetals<sup>1</sup>