Reactions of Cyclic Oxalyl Compounds, XXXIV. Synthesis of Dibenzoylacetate-N-carboxyalkylamides and Semiempirical Calculations of Keto-Enol Tautomers

Article abstract of DOI:10.1007/BF00810475

4-Benzoyl-5-phenylfuran-2,3-dione (1) and the urethanes 2 combine under loss of carbon monoxide yielding the open chain dibenzoylacetic acid derivatives 3 and 4. 3a, b only can be cyclized to the oxazinone 5.The keto-enole tautomerism 3 <-> 4 is further i