Five-membered 2,3-dioxoheterocycles:: LIX.: Reaction of 3-aroyl-1H-pyrrolo[2,1-c][1,4]benzoxazine-1,2,4-triones with acyclic β-enaminoesters.: Crystal and molecular structure of ethyl 3-benzoyl-4-hydroxy-1-o-hydroxyphenyl-5-oxo-2,3-dihydro-1H-pyrrolo-2-spiro-3′-(5-methyl-2-oxo-2,3-dihydro-1H-pyrrolo-4-carboxylate)