Crystal structure and preparation of wil forlide A

A pure wilforlide A was separated from the ethanolic extract of tripterygiu m wilfordii Hook. F. root. The compound was characterized by IR, H-1 NMR an d microanalysis. Its crystal structure was also determined by X-ray crystal lography. The title compound is formulated as C30H46O3 with formulae weight M-r = 454.70. Its crystal belongs to orthorhombic system with P2(1)2(1)2(1 ) space group. The crystal cell parameters are a = 0.732(4) nm, b = 1.283(7 ) nm, c = 2.693(6) nm; V = 2.532 7 nm(3), Z = 4, D,= 1.192 g(.)cm(-3), mu ( Mo K alpha) = 0.695 cm(-1), F(000) = 1 107. The final R = 0.039, R-W = 0.04 4. The title compound is a five-membered ring terpene, whole skeleton of mo lecule stretches folded. The results of AM1 calculation shows that the mole cule is polar and reactive to the nucleophilic and redox reactions.