Synthesis and Structure of 1-{2,2-Dimethyl-4,6-dioxo-5-(1-pyridinio)-1,3- dioxan-5-yl}pyridinium Ylide: A New Route to Meldrum’s Acid Derivatives

Abstract

2-Bromo-5,5-dimethyl-4,6-dioxo-1,3-dioxine (3) reacts with pyridine and aqueous potassium carbonate to give 1-{2,2-dimethyl-4,6-dioxo-5-(1-pyridinio)-1,3-dioxan-5-yl}pyridinium ylide (5). The crystal structure analysis confirms the betaine nature of 5 consisting of two distored ring fragments [interplanar angle 58.0(4)°] connected by a C-N single bond [1.440(1) Å ].