Zg. Aliev et al., CHEMISTRY OF 2-METHYLENE-2,3-DIHYDRO-3-FURANONES .13. INTERACTION OF YCARBONYLMETHYLENE-5-PHENYL-2,3-DIHYDRO-3-FURANONE WITH ACETONE AZINE, Russian chemical bulletin, 43(2), 1994, pp. 286-288
[3+2]-Cycloaddition of 2-methoxycarbonylmethylene-5-phenyl-2,3-furanon
e to acetone azine has been studied. This results in a monospirocycloa
dduct, viz., 9,9-dimethyl-6-methoxycarbonyl-2-phenyl- 1-oxa-7,8-diazas
piro[4.4]nona-2,6-dien-4-one. Its structure has been confirmed by X-ra
y diffraction analysis.