CRYSTAL STRUCTURE OF PICRIAFELTARRAGENIN EPOXY COMPOUND
苦玄参环氧甙元(Ⅰ)的晶体结构测定

Single crystals of picriafeltarragenin epoxy compound, C30H44O6, belong to space group P(212121) with lattice parameters a =28.373 (9)?, b=10.667 (5)?, c = 9.115 (4)? and 4 molecules in the unit cell. The intensities of 2890 independent reflectionsau collected using the PW-1100 fourcircle diffractometer. The structure was solved with MULTAN 78 program and refined to a final R = 0.084 by block diagonal least square method. Positions of all the hydrogen atoms were obtained from the difference Fourier synthesis. The shortest distance between two molecules is 3.5?.