Methyl (+/-)-1-ethyl-2-hydroxy-4-(4-methoxybenzoyl)-5-(4-methoxy-phenyl)-3-oxo-2,3-dihydro-1H-pyrrole-2-acetate

The title compound, C24H25NO7, is a racemic mixture of 2,3-dihydro- 1H-pyrrol-3-ones. It crystallizes in the triclinic system, space group P1, with Z = 2. The asymmetric unit contains two enantiomorphic molecules and the structure is stabilized by hydrogen-bond contacts

2(R)-hydroxy-4-(4-methoxybenzoyl)-2-methoxycarbonylmethyl-5-(4-methoxyphenyl)-1-(2-methylphenyl)-2,3-dihydro-1H-3-pyrrolone

The title compound, C29H27NO7, has a non-planar configuration. The methoxycarbonylmethyl group exhibits an E configuration. The crystal structure is stabilized by intermolecular O-H...O and C-H...O contacts

REACTIONS OF CYCLIC OXALYL COMPOUNDS .34. SYNTHESIS OF DIBENZOYLACETATE-N-CARBOXYALKYLAMIDES AND SEMIEMPIRICAL CALCULATIONS OF KETO-ENOL TAUTOMERS

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 half arrow right over half arrow left 4 is further investigated with aid of semiempirical quantum chemical calculations, based upon the molecular geometry of 3a, deduced from an X-ray study