CRYSTAL-STRUCTURE OF 10-OXA-3,4 BENZOBICYCLO [5.3.0] DECA-1(7) ENE-8,9 DIONE, C13H10O3

The crystal and molecular structure of the title compound, C13H10O3, d etermined by single crystal X-ray diffraction is reported. Crystals ar e triclinic, space group P ($) over bar 1, a=9.251(1), b=8.837(1), c=7 .091(1)Angstrom; alpha=85.6(1)degrees, beta=108.2(1)degrees, gamma=110 .1(1)degrees; V=517(3)Angstrom(3); Dx=1.38 mg m(-3), (MoK alpha)=0.710 7 Angstrom; mu=0.91 mm(-1); F(000)=224. The structure was solved by di rect methods and the final R value is 0.059 (omega R=0.078) for 1393 i ndependent observed reflections. In the crystal the cycloheptadienic m oiety adopts an approximate twist chair conformation with a pseudo-two fold axis and presents disorder.